text:
J. Electrochem. Sci. Technol > Volume 12(1); 2021 > Article
Akhtar, Lee, Kim, Park, and Yoon: Conduction Mechanism of Charge Carriers in Electrodes and Design Factors for the Improvement of Charge Conduction in Li-ion Batteries
Journal of Electrochemical Science and Technology 2021;12(1):1-20.
Conduction Mechanism of Charge Carriers in Electrodes and Design Factors for the Improvement of Charge Conduction in Li-ion Batteries
Sophia Akhtar1, Wontae Lee1,3, Minji Kim1, Min-Sik Park2,*, Won-Sub Yoon1,*
1Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea
2Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, 17104, Korea
3The Institute of New Paradigm of Energy Science Convergence, Sungkyunkwan University, Suwon 16419, Korea
*E-mail address: wsyoon@skku.edu, mspark@khu.ac.kr
Received October 16, 2020 Accepted November 28, 2020
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
In-depth knowledge of electrode processes is crucial for determining the electrochemical performance of lithium-ion batteries (LIBs). In particular, the conduction mechanisms of charged species in the electrodes, such as lithium ions (Li+) and electrons, are directly correlated with the performance of the battery because the overall reaction is dependent on the charge transport behavior in the electrodes. Therefore, it is necessary to understand the different electrochemical processes occurring in electrodes in order to elucidate the charge conduction phenomenon. Thus, it is essential to conduct fundamental studies on electrochemical processes to resolve the technical challenges and issues arising during the ionic and electronic conduction. Furthermore, it is also necessary to understand the transport of charged species as well as the predominant factors affecting their transport in electrodes. Based on such in-depth studies, potential approaches can be introduced to enhance the mobility of charged entities, thereby achieving superior battery performances. A clear understanding of the conduction mechanism inside electrodes can help overcome challenges associated with the rapid movement of charged species and provide a practical guideline for the development of advanced materials suitable for high-performance LIBs.
Keywords: Li-ion Battery, Charge Transport Mechanism, Ionic Conduction, Electron Conduction
Lithium (Li)-ion batteries (LIBs) are promising sources of power for various applications ranging from electronic devices to plug-in hybrid electric vehicles [1–4]. For the successful implementation of LIBs, it is crucial to meet the rigorous requirements of the industry. As far as the operation is concerned, LIBs should be safe and there must not be a fire hazard. [5]. A typical LIB is primarily composed of porous electrodes [6–7] (i.e., active material, conductive additive, and binder coated on the current collectors), an electrolyte, and a separator to prevent a short-circuit during operation. Multiple processes occur inside these porous electrodes during the operation of LIBs [8].
Generally, there are two types of charge transfer processes occurring inside electrodes that govern the appropriate operation of LIB; the first process is the electron transfer and the second process is the ion transfer. However, it is necessary to understand the percolation path of these charged entities at the interfaces when they move simultaneously during the operation of the battery.
The electrons are supplied by the current collectors for electrodes, while lithium ions (Li+) move through the active material and pores, thereby creating a pathway through the electrolyte. It should be noted that electron transfer through the electrolyte is undesirable because it could cause severe damage to the cell and may result in the explosion of the cell, leading to serious hazards. The electronic conduction in electrodes should occur fast; therefore, a conducting additive is generally used alongside the active materials. The suitable current collectors that can lead to rapid electron movement are aluminum (Al) foil for the cathode and copper (Cu) for the anode.
Further understanding of the charge transfer reactions at the electrode–electrolyte interface is crucial to control the reaction kinetics [9]. The reactions that do not occur at the electrode–electrolyte interface are typically irreversible and affect the performance of the electrochemical cell [10]. Hence, the overall reaction must only occur at the interface.
The interfacial reactions are mainly responsible for determining the reversibility of the electrochemical reactions in LIBs. The reversibility of electrochemical reactions directly reflects on the coulombic efficiency, although it does not significantly affect the energy density of LIBs [10–11].
Charge transport mechanisms in the electrodes are highly dependent on the properties of active materials, because electrochemical redox reactions mainly occur at the surface of these materials with the electron transport coupled to Li+ transport. Therefore, the rate-limiting factor could either be ion or electron transport at the electrodes, depending on the active materials [12].
Both ionic and electronic conduction at the electrodes are rate-limiting steps because the internal resistance of the electrodes affects the conduction path of both Li+ and electrons. The electronic transport is affected by the film resistance of current collectors, conducting additives, and surface resistance induced by the active materials in the electrodes. In contrast, ionic transport is mainly governed by the solid-state diffusion of Li+ in the active materials as well as the ionic resistance of the electrolyte. Consequently, both Li+ and electron conduction significantly affect the overall performance of LIBs [5].
Li+ and electron transport follow a 3D complex tortuous path in the electrodes. A complex tortuous path for the charged species is generally formed in electrodes impregnated with the electrolyte and consisting of current collectors coated with an active material, a conductive additive, and a polymeric binder. Generally, electron transport occurs through the conductive additive and active material, whereas Li+ transport occurs through the electrolyte-filled pores. Thus, Li+ and electron transport may follow a longer path when compared with the thickness of an electrode [13–16].
Electrode processes typically govern the working of a cell. The internal resistance of every part of the electrode restricts the movement of Li+ and electrons. This resistance is offered by the electrode [8] during (1) electron transfer at the boundary of the active material and current collector, (2) electron transport in the porous electrode, (3) ion transport in the electrolyte solution infused in the porous electrode, (4) Li+ transfer at the active material/electrolyte interface, (5) Li+ diffusion in the active material, and (6) ion transport in the electrolyte through the separator. Electronic conduction and ionic diffusion related electrochemical processes are explained in chapter 2 and 3 of this review, respectively.
2. Electron Conduction and Transport Mechanism
According to the band theory, the electronic conduction behavior of materials can be interpreted by analyzing their electronic band structures, as illustrated by quantum mechanics. In general, the materials have distinct band structures, which are predominant features for determining the electrical properties of materials such as insulators, conductors, and semiconductors. Conductors have partially filled valence bands, whereas semiconductors have overlapped bands, thereby enabling electrons to move in a crystal upon the application of an external field. Moreover, metals exhibit excellent electrical conductivity because they have zero band gap.
In LIBs, metals that exhibit excellent electrical conductivity, such as Cu and Al, are generally employed as the current collectors. Active materials (i.e., insulators) usually possess a large band gap (e.g., lithium cobalt oxide (LiCoO2) has a bandgap of 0.5–2.7 eV and electrical conductivity of ~10−4); hence, electron movement does not occur due to the filled valence and empty conduction bands [12]. The electronic conduction characteristics of active materials can be described using two approaches: classical transport theory and quantum transport theory.
2.1 Classical approach
The classical transport theory considers electrical conduction as a flow of free electrons. Under the application of an external electric field and the internal frictional force, the flow of free electrons attains equilibrium, and a constant current density is observed. By implementing the time relaxation approximation, the electrical conductivity can be expressed as follows [17]:
σ=Nfe2τm
where σ is the electrical conductivity, τ is the relaxation time, Nf is the number of free electrons, m is the mass of an electron, and e is the charge of an electron. A classical approximation is generally used to describe the typical electrical conduction in metals [18].
2.2 Quantum mechanical approach
The quantum mechanical approach states that only the electrons that are located near the Fermi level contribute to σ of the materials. Such electrons near the Fermi level can be accelerated via an external electrical field. Thus, electron movement only occurs along the direction of the applied field. The displaced free electrons possess equal or slightly higher velocities than the Fermi velocity (γF) [12]. These free electrons could participate in the electron conduction; hence, σ for a quantum mechanical system can be expressed as
σ=13e2vF2τN(EF)
Equation (2) describes the dependence of σ on the γF of free electrons, τ, and density of states. The abovementioned equation explains that σ is directly dependent on τ and the average time between successive collisions of free electrons [18].
σ can also be explained in terms of the absolute value of e and the number of conducting electrons, as expressed in equation (3) [17]. Electron mobility is a useful entity for describing the transport or conduction of electrons.
σ=n∣e∣μe
Quantum mechanics provides a range of concepts for a clear understanding of the influence of dopants and impurities in materials on altering carrier concentrations. The quantum mechanical expression for conductivity considers the electrons and density of states near the Fermi level; hence, it is more advantageous as compared to the classical model.
2.2.1 Electron tunneling and percolation path
Electron tunneling is an exponential function of the distance as well as the inverse barrier height for electron transfer. The probability of electron tunneling tends to decrease exponentially with an increase in the height and width of the electron transfer barrier.
T=|FA|2≈16Eo(V-Eo)V2e-2κL
In equation (4), T is the probability that an electron will tunnel through the barrier, Eo is the total energy of an incoming electron, V is the height of the potential barrier, L is the width of the potential barrier, and κ is the wave number.
An efficient electron transfer between the active material and the current collector affects the kinetic performance of the working electrode. In addition, electron tunneling and percolation throughout the active material also affects the electrochemical performance of the cell.
2.3 Conduction in active materials
2.3.1 Electron transfer between the current collector and active material
In general, an increase in V reduces the probability of electron tunneling during the operation of LIBs. Pan et al. demonstrated the presence of electronic conductive Cu2O and insulated Al2O3 surface oxidation layers on the surface of Cu and Al foils, respectively. The insulated Al2O3 layer forces the electrons to tunnel through the Al2O3 surface layer on the surface of Al foil. As a result, the working capacity of Li4Ti5O12 (LTO) on the Al foil was found to decrease due to the kinetic limitation at a high current density [19].
Yang et al. [20] examined the feasibility of a 3D-NiCrAl alloy foam as a current collector for LiFePO4 cathode material. The metal foam current collector enables efficient redox reactions owing to the shorter migration path of electrons and the large active surface area in the electrode. It should be noted that this short migration path of electrons and large surface area were advantageous for reducing the charge overpotential during the cycles, because electrons do not need to travel towards the current collector, similar to conventional foil-type current collectors.
The 3D-NiCrAl alloy foam features a roughened surface, which improves its adhesion with the active material, thereby reducing the interfacial resistance between the current collector and the active material.
On comparing the charge/discharge curves in Fig. 3(a), it is evident that there is no major difference in the charge overpotential in the plateau region of the two types of current collectors, at a low current density. At a high current density (Fig. 3(b)), however, a significant increase in the charge overpotential is observed in the plateau region of a foil-type current collector.
In addition, a significant capacity loss is observed in the foil-type current collector at a high current density due to the limited Li+ diffusion. In contrast, the metal foam current collector shows significantly lower capacity loss even at a high current density, as shown in Fig. 3(c). The increase in the internal resistance restricted the performance of the foil-type current collector.
The improved electrochemical performance is ascribed to the lower impedance and smaller polarization arising from the metal foam current collector. The metal foam exhibits a considerably smaller charge transfer resistance (Rct) at a high current density, as compared to the foil-type current collector [20].
2.3.2 Electron transport in porous electrodes
The high electronic conductivity of active materials is essential for the electron transfer in electrodes. Typically, additional carbon coatings are adopted for active materials with poor electronic conductivity, such as LiFePO4. The carbon coatings form electron percolation pathways in the electrode, resulting in improved electronic conductivity (Fig. 4).
A uniform carbon coating on the nanoporous micro-LiFePO4 cathode material can effectively form electron percolation pathways in the electrode, leading to a substantial increase in electronic conductivity. As a resul t, the volumetric capacity of nanoporous micro-LiFePO4 is 2.5 times higher than that of the nano-LiFePO4 (Fig. 5(a–c)). As shown in Fig. 5(d–e), nanoporous micro-LiFePO4 exhibits higher gravimetric and volumetric capacities at a high current rate.
The mutual effect of morphology and high electronic conductivity of nanoporous micro-LiFePO4 after carbon coating might be responsible for the higher gravimetric and volumetric capacities. The nanoporous particles combine the high capacity and high current rate of nano-sized particles with the high volumetric energy density of micro-sized particles [21].
3. Ionic Diffusion and Transport Mechanism
3.1 Macroscopic and microscopic diffusion processes
Generally, ionic transport occurs under the influence of different gradients such as the electrical field, chemical potential, and concentration. On a macroscopic scale, diffusion can be better explained by Fick's first law, as expressed by equation 5 [22]:
J=-DVC
where J is the flux of particles, C is the particle concentration, and D is the chemical diffusion coefficient. The negative sign specifies the gradient of the diffusion process, typically from higher to lower concentrations. At the microscopic scale, the self-diffusion coefficient is more useful because it provides additional information regarding the intrinsic nature of Li+ migration.
D*=16a2vexp(-EakBT)
In equation (6), Ea is the activation energy barrier for Li+ migration, ν is the vibration frequency of migrating Li+ in the lattice, kB is Boltzmann's constant, T is the absolute temperature, and a is the hopping distance [17].
3.2 Ionic conductivity
In electrochemical devices such as LIBs, ionic conductivity (σ) refers to the movement of Li+ under the influence of an external potential. The Nernst–Einstein equation describes the relationship between σ and D:
σiDi=Zi2F2CiRT
Di = chemical diffusion coefficient of species i,
R = gas constant,
T = absolute temperature,
σi = ionic conductivity of species i,
Zi = charge,
F =Faraday's constant, and
Ci = concentration of species i
Di can be related to ionic mobility through the Nernst–Planck equation. Equation (8) further illustrates this relationship:
Di=uikBT
where ui refers to the mobility for species I [17].
3.3 Diffusion mechanisms
Generally, microscopic diffusion is caused by the thermal energy of the material. Below the melting point, the amplitude of phonons at equilibrium is low, and the thermal energy plays a critical role in deviating the atoms from their mean positions by increasing the temperature. In an excited state, atoms tend to overcome the energy barrier, leading to atomic migration. However, some conditions must be satisfied before this atomic migration can occur. An adjacent empty site must be available, and the atom must possess certain energy to break neighboring bonds and cause lattice distortions, thereby leading to atomic migration.
A solid is never perfect, and there exist certain defects in the crystal lattice of solids. These defects exist in various forms within the solids, such as simple missing atoms (vacancies) and interstitial or substitutional impurities within the crystal lattice. The existence of defects not only governs the purity of the solid structure but also affects the material performance. Furthermore, the diffusion inside solids can be categorized into two types: vacancy assisted diffusion and non-vacancy assisted diffusion [22].
3.3.1 Vacancy-assisted diffusion process
The diffusion is governed by the perturbations of atoms in the equilibrium state. Vacancy-assisted diffusion occurs easily in the crystal lattice, as compared to non-vacancy assisted diffusion. In the vacancy-assisted diffusion process, atoms are exchanged from a normal lattice site to the adjacent vacancy. When the atoms diffuse along a particular direction, the vacancy simultaneously moves in a direction opposite to the atomic diffusion. Vacancy-assisted diffusion is directly related to the concentration of vacancies in the solid crystal lattices. When the vacancies are present in the crystal lattice, there is a relatively lower lattice strain during atomic hopping, and a lower activation energy barrier is experienced by the lattice atoms [22].
On charging LIBs, the removal of Li+ creates vacancies in the crystal structure of active materials (Fig. 6). The change in the lattice structure is rather small during the de/intercalation of Li+ in active materials, which is a crucial requirement for the improved and prolonged cycling performance of LIBs. The concentration of vacancies in the crystal structure plays a vital role in determining the pathway as well as the energy barrier for Li+ migration. Fanghua et al. [24] showed that LiCoO2 exhibited varying energy barriers and Li+ diffusion pathways due to the presence of monovacancies and divacancies.
3.3.2 Non-vacancy assisted diffusion process
As the lattice strain inside the crystal structure is elevated due to the absence of vacancies, non-vacancy assisted diffusion is more complicated. These interstitial atoms are occasionally impurities or solute atoms that are doped or mixed to alter material properties.
According to the direct interstitial diffusion mechanism, an interstitial atom moves to an adjacent site, and the lattice undergoes a significant amount of strain. However, there is no permanent strain in the lattice on the completion of the diffusion process, because the matrix atom displacement is temporary, as shown in Fig. 7(a). The sizes of the interstitial atoms are smaller than the sizes of the matrix atoms [22].
On the contrary, the knock-off migration mechanism represents an indirect interstitial mechanism wherein the size of the interstitial atom is equal to that of the matrix atom, as shown in Fig. 7(b). During the diffusion process, an interstitial atom pushes the matrix atom towards another interstitial site, inducing a large strain in the lattice. Chen et al. [25] stated that Li+ diffusion is dominated by the knock-off diffusion mechanism during the lithiation of Li7Ti5O12.
3.4 Ionic transport in a porous electrode
The ionic transport in the electrolyte impregnated in the porous electrode is a predominant factor for determining the rate capability of LIBs. Ogihara et al. [26,27] combined electrochemical impedance spectroscopy with a transmission line model theory for cylindrical pores, to understand the internal resistance inside electrolyte-infused porous electrodes.
As shown in Fig. 8, there are different types of internal resistance at the electrode–electrolyte interface. Moreover, the charge transfer resistance to Li+ and electron transport is dependent on the thickness of the electrode.
In the electrodes, ionic resistance in the pores (Rion) is affected by the pore length, whereas Rct is inversely proportional to the active surface area. Rion is mainly responsible for the Li+ conduction in pores filled with the electrolyte. Hence, the power capability of LIBs is strongly affected by the ionic conduction pathways in electrodes [27].
Fukutsuka et al. [8] conducted a model study involving anodic nanoporous alumina featuring a porous framework with honeycomb-shaped pores ranging from 20 to 68 nm. It was observed that the specific σ of the electrolyte infused in the honeycomb pores was smaller than that of the bulk electrolyte solution (i.e., 7.6 mS/cm), regardless of the pore size. The Nyquist plots exhibited depressed semi-circles, referring to the presence of ionic transport resistance in the honeycomb pores. The plots also indicated the existence of the capacitive element associated with the ionic transport inside the active material. Hence, the specific σ of the electrolyte solution impregnated in the porous electrode influences the ionic transport resistance of the electrodes [8].
3.5 Ion transfer at the interface between the active material and electrolyte
The electrochemical kinetics at the electrodes of LIBs are affected by multiple factors. One of these factors is the charge transfer process involved at the electrode–electrolyte interface. Thus, it is also necessary to understand the reaction kinetics of the active materials. Abe et al. [28] evaluated the activation energy required for desolvation at the electrode–electrolyte interface. The semi-circles in the Nyquist plots were influenced by the salt concentration of the electrolyte and the electrode potential. The resistance is inversely proportional to the salt concentration of the electrolyte. The activation energy values were calculated for the de-solvated and solvated Li+ transfer based on the charge-transfer resistance vs temperature plots. The activation energy values for Li+ solvation were observed to be half of those required for the desolvation process [29].
On the contrary, solid electrolyte interphase (SEI) is a passive layer formed on the surface of the electrodes through the decomposition of electrolytes. The interphases assist in the reversible Li+ de/intercalation during the operation of LIBs, while restricting parasitic reactions.
Xu et al. [11] explained the interphasial reactions for solvation and desolvation. The solvation sheath of Li+ is composed of the solvent molecules that bind together with the Li+ core. These molecules are stabilized and remain undisplaced owing to the strong coulombic forces exerted by Li+ on its surrounding molecules.
This sheath tends to stabilize Li+ in the electrolyte by compensating the increase of Gibbs free energy. When Li+ intercalates into the graphite anode, this solvation sheath must be stripped out because the SEI on the graphite surface only allows the intercalation of naked Li+. This corresponds to the existence of a high energy transition state, as shown in Fig. 9. The desolvation process induces an additional resistance to Li+ transport and is a rate-determining step at the electrode–electrolyte interface [11].
3.6 Li+ diffusion in the active material
Ionic diffusion inside the active materials plays a vital role in determining the performance of LIBs. Ionic diffusion is generally favorable inside the battery; however, leakage current should be avoided. Since the rate capability of LIBs depends on the ionic charge transfer kinetics, it is important to understand the critical factors governing charge transfer, to evaluate the power characteristics of LIBs [30]. In LIBs, the Li+ de/intercalation process begins with the dissociation of Li+-electron pairs and ends with the concomitant entry of Li+-electron pairs into active materials via solid-state diffusion [31]. Ionic diffusivity (Dionic), as expressed in equation (9), is a parameter to characterize the ease of Li+ movement in active materials:
Dionic=D0exp(-ΔGkBT)
A decrease in the energy barrier can increase Li+ diffusivity (DLi). Although an increase in operating temperature (T) enhances diffusivity, it can pose a threat to safety.
τd=λ2Dionic
Dionic at the surface must be enhanced to shorten the diffusion time (τd) expressed by equation (10), and the electron/ion diffusion length (λ) should be reduced [31]. The following schematic describes the diffusion pathways of Li+ within the active material.
As depicted in Fig. 10, during Li+ diffusion in the electrode, the ions sequentially move through different parts of the electrode, namely the crystal structures, primary particles, secondary particles, porous electrodes, and bulk electrolyte [32]. Although the energy density of an LIB can be improved by increasing the thickness of the electrode, the Li+ kinetics is significantly reduced.
As shown in Fig. 11(a–b), the thicker electrodes exhibited a significant capacity loss coupled with a low coulombic efficiency. τd is a function of electrode thickness; therefore, the time required for Li+ diffusion increased with an increase in electrode thickness. DLi also depends on electrode thickness and directly affects the specific capacity and rate capability of LIBs (Fig. 11(c)). During the operation of LIBs, a rapid decrease in DLi was observed for thicker electrodes due to the localized oversaturation or over-depletion of Li+ induced by the slower Li+ transport [32].
3.7 Ion transport in the bulk electrolyte through the separator
Thin separators are more suitable for enhancing the performance of LIBs, because thick separators are not feasible owing to their poor ionic conductivity. A thin separator typically possesses high porosity, which enables enhanced mass transport through the pores with reduced resistance from the electrolyte. Thus, the porosity of separators is a crucial factor in determining the internal resistance of LIBs. A uniform porosity of separators is desirable for maintaining a uniform current density with a smooth ionic current flow inside the LIBs. A non-uniform current density can cause a significant reduction in performance [33].
As the resistance is also affected by the pore structure of the separators, the total pore volume and pore size of separators could be tailored to enhance σ by decreasing the thickness of the separators (Fig. 12). A thinner separator enables an increase in the mass transportation of ions, thereby effectively lowering the resistance even at high current densities. For improving cycling performance and rate capability, the separator should be as thin as possible to minimize the cell resistance but still be able to maintain high ionic conductivity.
Pan et al. [34] demonstrated that small over-potential and high specific capacity of LiFePO4 could be attained by employing a thin separator even at high current densities.
As shown in Table 1 and Figs. 12 and 13(a–c), the lowest cell resistance was observed for Cladophora cellulose (CC)-25 separator with the highest porosity and lowest thickness. This supports the hypothesis that a reduction in the ionic transport path is beneficial for lowering cell resistance. As shown in Fig. 13(d–e), the cycling performance of CC-25 is superior to other samples due to the lower cell resistance.
4. Material Engineering
The material design is the most crucial step when developing high-performance LIBs.
Structural modifications of active materials are effective methods to reduce the interfacial resistance during electrode processes. Some of the effective structural modifications of active materials, depending on the type of active materials and interface scenarios, for improving the electrochemical performance of LIBs are briefly explained in the following section.
4.1 Surface modifications
Li-rich cathode materials, commonly known as over-lithiated oxides (OLOs), have received significant attention as promising cathode materials for LIBs. In particular, lithium manganese oxide (Li2MnO3), which has a monoclinic structure of the C2/m space group, can offer a high capacity of 300 mAh/g on an initial charge to 4.8 V vs Li/Li+. However, the practical use of Li2MnO3 is limited due to the low coulombic efficiency and irreversible capacity loss during the first cycle. Kim et al. [35] reported a positive effect of the TiO2 surface coating on Li2MnO3, where TiO2 acts as a suitable alternative for improving the structural stability of Li2MnO3. TiO2-coated Li2MnO3 exhibited a relatively lower interfacial resistance, as compared with that of uncoated Li2MnO3. TiO2 acted as a stabilizer and prevented the decomposition of the active material in the electrolyte at high potentials, thereby improving the rate performance of TiO2-coated Li2MnO3. LiCoO2 has an α-NaFeO2 layered structure, which assists in efficient reversible Li+ intercalation chemistry. Despite its high theoretical capacity, the working capacity of LiCoO2 is limited to just 140 mAh/g. This limited capacity of LiCoO2 originates from a factual phase transition (at >4.2 V) from a hexagonal to a monoclinic structure, causing a decrease in the coulombic efficiency. This leads to a decrease in Li+ diffusion, resulting in high internal strain and degradation of mechanical properties.
A large number of LiCoO2 surface coatings have been explored to overcome these problems. In particular, surface coatings containing metallic compounds were found to be effective because they act as a barrier between the electrolyte and the LiCoO2 particles. Kaluri et al. [36] reported a hybrid surface coating consisting of magnesium (Mg) and phosphorous (P) on the surface of LiCoO2.
A surface coating consisting of Mg and P can be effective for improving the electrochemical performance and thermal stability of LiCoO2 (Fig. 14(a)). After surface coating, Mg and P (MP)-coated LiCoO2 exhibited a high-capacity retention of 86.5%, even after 100 cycles. As shown in Fig. 14(b–c), the rate capability of MP-coated LiCoO2 was nearly 25 times higher than the rate capability of bare LiCoO2, even at a high current density of 10 C [37].
The decrease in the capacity of bare LiCoO2 cathode could be attributed to the structural degradation at high operating temperatures [36]. As a result, a significant dissolution of Co in the electrolyte was observed based on FIB post mortem analyses (Fig. 14(a)).
In addition, post-processes (i.e., heat-treatment and washing) can improve the rate performance of nickel (Ni)-rich layered materials. The surface of a treated, Ni-rich layered material is considerably cleaner than that of an untreated material, as shown in Fig. 15. As a result, treated cathodes exhibit a significantly higher rate performance than untreated materials due to the reduction in surface contamination [38].
4.2 Size control
4.2.1 Particle size effect
Nanostructured materials typically possess large surface areas as compared to bulk materials. Thus, it should be noted that reducing the particle size would be a wise strategy for increasing the surface area of active materials. The properties of active materials change drastically at the nanometer scale because the active surface area is enlarged. In LIBs, the diffusion distance and DLi are correlated to the particle size of active materials, which directly affects the movement of Li+ inside the active materials of electrodes [39].
Jiang et al. [40] studied the effect of the particle size of anatase TiO2 on the electrochemical performance of active materials. A decrease in the particle size of anatase TiO2 reduces the interstitial sites for Li+ insertion, resulting in a reduced diffusion or transport length of Li+; this improves the rate capability. Anatase TiO2 featuring a particle size of 6 nm exhibited a more stable cycling performance, as compared to other materials. Thus, a reduction in particle size increases the active surface area of active materials and facilitates the de/intercalation of Li+, thereby leading to an improvement in the rate capability as well as the specific capacity [40].
4.2.2 SEI Thickness
Liu et al. [41] demonstrated the enhanced performance of LIBs by employing chemically active multifunctional separators (MFSs). From a microscopic perspective, the capacity retention of electrodes can be increased through a simultaneous reduction in the interfacial resistance. MFSs would suppress parasitic reactions at the interfaces and reduce the SEI film thickness on electrodes, leading to a reduction in the interfacial resistance.
The cycling performance and capacity retention of LIBs could be improved through the lower interfacial resistance achieved by a reduction in the SEI film thickness. A thin SEI film enables a homogeneous distribution of current on the electrode surface, leading to an improved performance of the LIB.
4.3 Synergetic effect of the conductive binder
As a commercial binder, PVDF is commonly used for electrode fabrication owing to its excellent electrochemical stability and binding property. However, the insulator PVDF induces an increase in the internal resistance of the electrodes. Ling et al. [42] incorporated naturally occurring conductive binder sodium alginate (SA) along with poly(3,4-propylene-dioxythiopene) (PProDOT) in electrodes, as shown in Fig. 16 (a).
As shown in Fig. 16(b), the electrochemical performance of LiFePO4 could be improved by employing the conductive SA-PProDOT binder. The cycling performance and capacity retention of LiFePO4 are depicted in Fig. 16 (c–d). The capacity retention of LiFePO4 with the SA-PProDOT binder was estimated to be 86.6%, without a significant capacity loss even at a high current density of 1 C. Moreover, excellent Coulombic efficiency was noticeable even after 400 cycles. This clearly indicated that the conductive SA-PProDOT binder would be beneficial for improving electrochemical performance owing to its conductive nature [42].
4.4 Nano-structuring
Nano-structuring is useful for tailoring active materials so as to obtain desirable morphologies and microstructures such as particles, wires, sheets, and hollow porous structures. A short diffusion length and large surface area of nanostructured active materials could enhance the rate of ionic and electronic transport at the electrode–electrolyte interface. At the nanoscale, materials tend to have a large surface area, which is responsible for facilitating electrochemical reactions at the interfaces inside electrodes. Nanostructured materials lead to a decrease in the thermodynamic activation energy barrier at the electrode–electrolyte interface [31,43]. For example, LTO is a commonly used active material featuring a high capacity and a suitable potential window. However, due to its low conductivity, the insertion of Li+ in bulk LTO is limited. However, this could be further enhanced by decreasing the crystallite or particle size via nano-structuring. Feckl et al. [44] reported that Li+ insertion is greater in nano-LTO than in porous LTO.
As shown in Fig. 17, nano-LTO-400 with a particle size of 3 nm exhibited a better cycling performance, as compared to nano-LTO-500 with a particle size of 6 nm. Such an improvement in the performance can be explained by the enhanced insertion of Li+ induced by the smaller crystallite size [44].
4.5 Dopant manipulation
Simultaneously achieving high energy and high power at robust charging and discharging rates is a crucial requirement for the development of LIBs. Currently, LIBs still suffer from low power densities due to the use of bulk materials as active materials. Although bulk metal oxides or graphite anodes can offer high energy densities, the power density achieved is limited by the slow kinetics in bulk materials. The power characteristics of LIBs are dependent on efficient charge storage capability and also on the kinetics of charge transport during electrochemical reactions in the bulk electrode and electrolyte. Doping or substitution in bulk materials is an effective approach to introduce ions, heteroatoms, or vacancies in the crystal structure; this in turn enhances conductivity due to the excess or deficiency of charged species, leading to an improvement in the overall performance of the battery. Wu et al. [45] reported the substitution of nitrogen (N) and boron (B) atoms in place of carbon (C) atoms on the edges of graphite. B and N doping in graphene facilitates Li+ intercalation into the host structure of graphite and enhances electrical conductivity, thereby leading to high power and energy densities.
Graphene exhibited an enhanced coulombic efficiency during the cycles, after N and B doping, as shown in Fig. 18. The reversible capacity retentions for N-doped and B-doped graphene were measured to be 83.6% and 79.2%, respectively. The improvements in the parameters indicated the effective suppression of side reactions and electrolyte decomposition as well as the enhancement in Li+ absorption and the diffusion inside electrodes [45].
In addition, the Li+ diffusion path length in the 2D layered system can be controlled through the dopant ratio. For instance, the inter-slab size of LiO6 in the Nirich layered material can be increased by reducing the amount of Mn ions (Fig. 19). Consequently, this leads to a favorable environment for Ni2+ to diffuse in the Li layer (i.e., lowering the activation energy). Therefore, NCM721 exhibits a significantly higher DLi than NCM523 [46].
4.6 Hybrid composite design
A hybrid composite approach involves the synthesis of various composite materials by integrating conducting additives into active materials. The conducting additives induce the formation of sufficient conduction pathways in the electrodes. In addition to increasing the electrical conductivity, these conducting additives tend to decrease the length of Li+ diffusion, enabling faster Li+ de/intercalation.
Magasinski et al. reported a porous silicon (Si)-C composite containing irregular open channels that facilitate the adsorption and diffusion of Li+ within the composite material. Si typically undergoes a large volume expansion; however, in this case, the volume expansion of Si could be compensated by integrating free spaces in the composite. The Si-C composite exhibited better capacity retentions at high current densities, compared with those of simply annealed carbon black [47]. Thus, hybrid composites with a conducting additive could be a practical approach for further improving the electrochemical performance of the active materials in LIBs.
Currently, LIBs are associated with a major challenge that can only be overcome through a comprehensive understanding of the processes occurring at the electrode–electrolyte interface. Advanced materials can be efficiently designed only after obtaining an in-depth understanding of multiple electrode processes and interfacial reactions occurring at the electrodes. Conducting species always follow the path that offers the minimum transport resistance. Thus, the internal resistance to the transport of charged species depends on multiple intrinsic and extrinsic factors of the electrodes. The porous structure of the electrodes provides abundant interconnected open pores that enable electrolyte absorption, which considerably decreases the diffusion path of Li+. Understanding the basic scientific principles governing Li+ diffusion and electron transport in electrodes can help accelerate the pace of future research on improving the performance of LIBs. Reducing the resistance to the transport of charged species in electrodes would prove to be beneficial for achieving faster kinetics and enhanced electrochemical performance in the future.
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. NRF-2019R1A2C2003731).
Electrode–electrolyte interfaces in Li-ion, Li-polymer, and all solid-state Li-based batteries. The figures were reproduced with permission from Ref. [10]. Copyright 2018, Energy and Environmental Science.
Electrochemical processes occurring within a Li-ion battery electrode.
Electrochemical performance of metal foam and foil-type current collector at (a) 0.1 C and (b) 1.0 C. (c) Cyclic stability and electrochemical impedance spectroscopic curves for metal foam and foil-type current collectors. The figures were reproduced with permission from Ref. [20]. Copyright 2014, Journal of Material Chemistry A.
(a–d) SEM micrographs of nanoporous micro-LiFePO4 and nano-LiFePO4, and (e) schematic diagram of electronic conduction through the active material. The figures were reproduced with permission from Ref. [21]. Copyright 2009, Electrochemical Solid-State Letters.
Charge-discharge curves for (a) gravimetric capacity and (b) volumetric capacity, and (c) cyclability of nano-LiFePO4 and nanoporous micro-LiFePO4. (d) Gravimetric and (e) volumetric capacities of nano-LiFePO4 and nanoporous micro-LiFePO4. The figures were reproduced with permission from Ref. [21]. Copyright 2009, Electrochemical Solid-State Letters.
Vacancy-assisted diffusion in a crystal lattice. The figure was reproduced with permission from Ref. [23]. Copyright 2003, Encyclopedia of Applied Physics.
(a) Direct interstitial diffusion in a crystal lattice. (b) Knock-off migration mechanism. The figure was reproduced with permission from Ref. [23]. Copyright 2003, Encyclopedia of Applied Physics.
Internal resistance in a porous electrode. The figure was reproduced with permission from Ref. [26]. Copyright 2012, Journal of Electrochemical Society.
Interphasial resistance from two sub-processes: (a) desolvation of Li+ and (b) migration of naked Li+ across the interphase. The figure was reproduced with permission from Ref. [11]. Copyright 2011, Journal of Material Chemistry.
Schematic diagram indicating Li+ diffusion pathways. The figures were reproduced with permission from Ref. [32]. Copyright 2018, The Journal of Physical Chemistry Letters.
(a) Coulombic efficiency and irreversible capacity of electrodes during the first cycle and (b) voltage profiles with varying thickness. (c) Li+ diffusivity. The figures were reproduced with permission from Ref. [32]. Copyright 2018, The Journal of Physical Chemistry Letters.
(a) Dependency of the pore size on the thickness of the separator. (b) Digital images, (c) surface SEM, and (d) cross-section SEM images of Cladophora cellulose separator. The figures were reproduced with permission from Ref. [34]. Copyright 2017, Cellulose.
Charge-discharge curves at various cycling rates for the (a) CC-25, (b) CC-50, and (c) CC-100 based cells. (d) Nyquist and (e) capacity retention plots of Cladophora cellulose (CC) separators. The figures were reproduced with permission from Ref. [34]. Copyright 2017, Cellulose.
(a) FIB micrographs of bare and MP-coated LiCoO2 particles. Cycling stability of bare and MP-coated LiCoO2 at (a) 25°C and (b) 60°C. The figures were reproduced with permission from Ref. [36]. Copyright 2017, Advanced Energy Materials.
Schematic of post-processes (washing and heating) of Ni-rich layered cathode materials, SEM images for untreated (before) and treated (after) materials, and rate performances. The figures were reproduced with permission from Ref. [38]. Copyright 2020, Journal of Materials Chemistry A.
(a) Micro-emulsion system for SA-PProDOT and (b) galvanostatic discharge profiles of LiFePO4 with different binders. (c) Rate performance of LiFePO4 and (d) LiFePO4 performance for different types of binders. The figures were reproduced with permission from Ref. [42]. Copyright 2015, Nano Letters.
(a) Multi-cycling stability of nano-LTO-400 (gray symbol) and nano-LTO-500 (black symbol) at different rates and (b) HR-TEM image of nano-sized LTO at 400°C. The figures were reproduced with permission from Ref. [44]. Copyright 2012, Angewandte Chemie.
Electrochemical performance of (a, c) of N- and B-doped graphene electrode and (b, d) coulombic efficiency and cycle performance of N- and B-doped graphene electrode vs Li+/Li. The figures were reproduced with permission from Ref. [45]. Copyright 2011, ACS Nano.
Illustration of LiNi0.5+xCo0.2Mn0.3−xO2 (x = 0, 0.1, and 0.2) layered structure, slab thickness, and diffusion coefficients of each material during charging. The figures were reproduced with permission from Ref. [46]. Copyright 2017, Advanced Energy Materials
Properties of Cladophora cellulose (CC) separators. The table was reproduced with permission from Ref. [34]. Copyright 2017, Cellulose.
Thickness (μm)
Pore size (nm)
Porosity (%)
σ (mS/cm)
CC-25 10 21 44 0.82
CC-100 40 12 33 0.69
[1] M. Wang, Y. Tian, W. Liu, R. Zhang, L. Chen, L. Yinda and L. Xin, J Clean Prod, 2020, 265, 121769.
[2] L. Zhang, X. Qin, S. Zhao, A. Wang, J. Luo, ZL. Wang, F. Kang, Z. Lin and B. Li, Adv Mater, 2020, 33, 1908445.
[3] Q. Zhang, N. Cui, Y. Li, B. Duan and C. Zhang, J Energy Storage, 2020, 27, 100945.
[4] Z. Chen, J. Lu, B. Liu, N. Zhou and S. Li, Energies, 2020, 13(10), 2543.
[5] Y. Orikasa, Y. Gogyo, H. Yamashige, M. Katayama, K. Chen, T. Mori, K. Yamamoto, T. Masese, Y. Inada, T. Ohta, Z. Siroma, S. Kato, H. Kinoshita, H. Arai, Z. Ogumi and Y. Uchimoto, Sci Rep, 2016, 6, 26382.
[6] Y. Itou, N. Ogihara and S. Kawauchi, J Phys Chem C, 2020, 124(10), 5559–5564.
[7] A. Chu, A. Allam, A. Cordoba Arenas, S. Rizzoni and G. Onori, J Power Sources, 2020, 478, 228991.
[8] T. Fukutsuka, K. Koyamada, S. Maruyama, K. Miyazaki and T. Abe, Electrochim Acta, 2016, 199, 380–387.
[9] A. Yano, K. Hikima, J. Hata, K. Suzuki, M. Hirayama and R. Kanno, J Electrochem Soc, 2018, 165(14), A3221.
[10] X. Yu and A. Manthiram, Energy Environ Sci, 2018, 11(3), 527–543.
[11] K. Xu and A. Von Cresce, J Mater Chem, 2011, 21(27), 9849–9864.
[12] M. Park, X. Zhang, M. Chung, GB. Less and AM. Sastry, J Power Sources, 2010, 195(24), 7904–7929.
[13] CJ. Bae, CK. Erdonmez, JW. Halloran and YM. Chiang, Adv Mater, 2013, 25(9), 1254–1258.
[14] D. Kehrwald, PR. Shearing, NP. Brandon, PK. Sinha and SJ. Harris, J Electrochem Soc, 2011, 158(12), A1393.
[15] Y. Ren, AR. Armstrong, F. Jiao and PG. Bruce, J Am Chem Soc, 2010, 132(3), 996–1004.
[16] B. Vijayaraghavan, DR. Ely, Y-M. Chiang, R. García-García and RE. García, J Electrochem Soc, 2012, 159(5), A548.
[17] RE. Hummel, Electronic Properties of Materials-Springer-Verlag, 2011.
[19] HL. Pan, YS. Hu, H. Li and LQ. Chen, Chinese Phys B, 2011, 20(11), 118202.
[20] GF. Yang, KY. Song and SK. Joo, J Mater Chem A, 2014, 2(46), 19648–19652.
[21] SW. Oh, S-T. Myung, HJ. Bang, CS. Yoon, K. Amine and Y-K. Sun, Electrochem Solid-State Lett, 2009, 12(9), A181.
[22] H. Mehrer, Diffusion in SolidsFundamentals, Methods, Materials, Diffusion-Controlled Processes. Springer-Verlag, Berlin Heidelberg, 2003. p.1–651.
[23] AV. Chadwick, Encycl Appl Phys, 2003, 193–222.
[24] F. Ning, S. Li, B. Xu and C. Ouyang, Solid State Ionics, 2014, 263, 46–48.
[25] YC. Chen, CY. Ouyang, LJ. Song and ZL. Sun, Electrochim Acta, 2011, 56(17), 6084–6088.
[26] N. Ogihara, S. Kawauchi, C. Okuda, Y. Itou, Y. Takeuchi and Y. Ukyo, J Electrochem Soc, 2012, 159(7), A1034.
[27] N. Ogihara, Y. Itou, T. Sasaki and Y. Takeuchi, J Phys Chem C, 2015, 119(9), 4612–4619.
[28] T. Abe, H. Fukuda, Y. Iriyama and Z. Ogumi, J Electrochem Soc, 2004, 151(8), A1120.
[29] Z. Ogumi, Electrochemistry, 2010, 78(5), 319–324.
[30] TR. Jow, SA. Delp, JL. Allen, J-P. Jones and MC. Smart, J Electrochem Soc, 2018, 165(2), A361.
[31] Y. Tang, Y. Zhang, W. Li, B. Ma and X. Chen, Chem Soc Rev, 2015, 44(17), 5926–5940.
[32] H. Gao, Q. Wu, Y. Hu, JP. Zheng, K. Amine and Z. Chen, J Phys Chem Lett, 2018, 9(17), 5100–5104.
[33] P. Arora and Z. Zhang, Chem Rev, 2004, 104, 4419–4462.
[34] R. Pan, Z. Wang, R. Sun, J. Lindh, K. Edström, M. Str⊘mme and L. Nyholm, Cellulose, 2017, 24(7), 2903–2911.
[35] SJ. Kim, MC. Kim, DH. Kwak, DM. Kim, GH. Lee, HS. Choe and KW. Park, J Power Sources, 2016, 304, 119–127.
[36] S. Kalluri, M. Yoon, M. Jo, S. Park, S. Myeong, J. Kim, SX. Dou, Z. Guo and J. Cho, Adv Energy Mater, 2017, 7(1), 1601507.
[37] J. Qian, L. Liu, J. Yang, S. Li, X. Wang, HL. Zhuang and Y. Lu, Nat Commun, 2018, 9(1), 1–11.
[38] W. Lee, D. Lee, Y. Kim, W. Choi and W-S. Yoon, J Mater Chem A, 2020, 8(20), 10206–10216.
[39] KX. Wang, XH. Li and JS. Chen, Adv Mater, 2015, 27(3), 527–545.
[40] C. Jiang, M. Wei, Z. Qi, T. Kudo, I. Honma and H. Zhou, J Power Sources, 2007, 166(1), 239–243.
[41] H. Liu, A. Banerjee, B. Ziv, KJ. Harris, NPW. Pieczonka, S. Luski, GA. Botton, GR. Goward, D. Aurbach and IC. Halalay, ACS Appl Energy Mater, 2018, 1(5), 1878–1882.
[42] M. Ling, J. Qiu, S. Li, C. Yan, MJ. Kiefel, G. Liu and S. Zhang, Nano Lett, 2015, 15(7), 4440–4447.
[43] J. Wang, N. Yang, H. Tang, Z. Dong, Q. Jin, M. Yang, D. Kisailus, H. Zhao, Z. Tang and D. Wang, Angew Chemie, 2013, 52(25), 6417–6420.
[44] JM. Feckl, K. Fominykh, M. Dblinger, D. FattakhovaRohlfing and T. Bein, Angew Chemie, 2012, 51(30), 7459–7463.
[45] ZS. Wu, W. Ren, L. Xu, F. Li and HM. Cheng, ACS Nano, 2011, 5(7), 5463–5471.
[46] W. Lee, S. Muhammad, T. Kim, H. Kim, E. Lee, M. Jeong, S. Son, JH. Ryou and WS. Yoon, Adv Energy Mater, 2018, 8(4), 1701788.
[47] A. Magasinski, P. Dixon, B. Hertzberg, A. Kvit, J. Ayala and G. Yushin, Nat Mater, 2010, 9(4), 353–358.
14 Scopus
Related articles in J. Electrochem. Sci. Technol


text:
Around Danvers
"Get to Know Your E-Reader" program: 3-4:30 p.m. Jan. 9, Second Floor Technology Lab at the Peabody Institute Main Library, 82 Main St., Peabody. Free; registration is required. To register: 978-531-0100, ext. 24; peabodylibrary.org. Participants can bring their e-readers or tablets and learn how to download ebooks; use free library services like Overdrive, Libby, and Hoopla; and pick up basic troubleshooting techniques. Participants should also bring any login information and an instruction manual for their device, if available. The library does not have any e-readers or tablets available for public use.
"The Healing Power of Nature" program: 7 p.m. Jan. 10, Peabody Institute Library of Danvers, 15 Sylvan St. Clinical social worker Mary Jacobsen will provide an overview of research on nature's healing impacts on physical, cognitive and emotional well-being at all stages of life. Jacobsen worked as a psychotherapist for many years and has also worked as a teacher-naturalist for Mass Audubon. Her studies about the healing power of nature form a bridge between her professional worlds of psychotherapy and nature.
Red Cross blood drive: 8:30 a.m.-2 p.m. Jan. 11-13; and 12:45-6:15 p.m. Jan. 7-10 and 14-15, Danvers Blood Donation Center, 99 Rosewood Drive. Also 2-7 p.m. Jan. 4, Amity Mosaic Lodge, 30 High St. For information: 800-733-2767; http://redcrossblood.org. Blood can be donated every 56 days.
Don White performance: 6:30 p.m. Jan. 11, North Shore Unitarian Universalist Church, 323 Locust St. (Route 35), Danvers. Cost: $15. For information: https://nsuu.org; 978-729-5422. In his 30-year career, this comedian, singer-songwriter and storyteller from Lynn has opened for Arlo Guthrie, Ritchie Havens, Louden Wainwright III and Taj Mahal and shared a bill with David Bromberg, Janis Ian and Lyle Lovett.
Peabody Institute Library of Danvers community forum: 11 a.m. Jan. 12, Gordon Room, Peabody Institute Library of Danvers, 15 Sylvan St. Free. For information: https://www.danverslibrary.org. Director Alex Lent and library trustees are looking to encourage residents to think of ways the library can be even more useful to the Danvers community. All Danvers residents and library users are welcome to attend. Light refreshments will be served.
Teen Israel Advocacy Fellows annual recognition ceremony: 6:30-8 p.m. Jan. 13, Temple Ner Tamid, 368 Lowell St., Peabody. Free. To RSVP and for information: Susan Feinstein, 978-740-4431; sfeinstein@lappinfoundation.org. Lappin Foundation and the Consulate General of Israel to New England will recognize teens for their exceptional leadership, commitment to Israel advocacy and dedication to Israel. Jacob Baime, executive director of Israel on Campus Coalition, will be the keynote speaker, and congratulatory remarks will be made by Daniel Agronov, deputy consul general of Israel to New England.
Tu B'Shevat celebration: 11 a.m.-noon Jan. 13, Temple B'nai Abraham, 200 Lothrop St., Beverly. Free. For information or to RSVP: 978-740-4404, Phyllis Osher; posher@lappinfoundation.org. Lappin Foundation and Temple B'nai Abraham invite families with children ages 6 and younger to celebrate the birthday of the trees with planting, a PJ Library story, crafts and light snacks. Walk-ins are welcome.
Teen Room Tea Party: 4:30 p.m. Jan. 14, Teen Room, Peabody Institute Library, Main Library, 82 Main St., Peabody. Free. To register and for information: www.peabodylibrary.org; 978-531-0100, ext. 35. Open to teens in grades six through 12. Participants will learn traditional tea-brewing methods and the origin of tea while enjoying calming music, snacks and relaxation time.
"Strengths-based Management Styles" program: 8-10 a.m. Jan. 16, North Shore Community College Danvers Campus, 1 Ferncroft Road, DS106. Cost: $49. For information or to register: Susan Ryan, 978-236-1240. Part of NSCC's Supervisors' Connection Workshop series.
Tribute to Martin Luther King Jr.: 4-6 p.m. Jan. 21, Danvers High School Atrium, 60 Cabot Road. Free. For information: https://bit.ly/2RIc6AZ. The 21st annual event will feature remarks from Rabbi Allison Adler of Temple B'Nai Abraham of Beverly; music by Danvers High School's Chamber Singers, St. John's Prep's "Swingtown!" and the North Shore Unitarian Universalist Church Singing Group; readings of selections of Dr. King's writings; and a video produced by student representatives to the Danvers School Committee. The event is presented by the Danvers Committee for Human Rights and Inclusion and Danvers Public Schools.
DanversCARES Family Workshop Series: 6-7:30 p.m. Jan. 22, Gordon Room, Peabody Institute Library, 15 Sylvan St., Danvers. Free. For information: Sheryl James, sheryljames@danvers.org; 978-335-3484. To register: https://bit.ly/2BLlMRc. The workshop series is geared to Danvers families with children ages 5-11. This session's topic is "Developmental Stages."
"How to Speak So Your Legislators will Listen" program: 7 p.m. Jan. 22, Peabody Institute Library of Danvers, 15 Sylvan St. Free For information: 978-774-0554; danverslibrary.org. Nancy Brumback, chair of the League of Women Voters of Massachusetts' Legislative Action Committee, will discuss at what points in the legislation process communication from constituents is most effective and why it is important to contact legislators when you know they agree with you. A Q&A session will be held afterward. This is a nonpartisan event.
"Online Privacy and Digital Safety" program: 3-4:30 p.m. Jan. 23, Second Floor Technology Lab at the Peabody Institute Main Library, 82 Main St., Peabody. Free; registration is required. To register: 978-531-0100, ext. 24; peabodylibrary.org. This discussion on best practices for digital safety and privacy will include browsers, digital tracking, passwords, avoiding scams and managing social media settings.
Introduction to Modern Square Dancing: 7-9 p.m. Jan. 30, All Saints Episcopal Church, 13 Holten St., Danvers. Free. For information: 978-774-8159 ; riversidesquares.org; https://bit.ly/2Fey7R8. Riverside Square Dance Club will offer an introductory night of modern square dancing as well as free soups and other entertainment. No partner is necessary. Anyone who can walk briskly can square dance. Classes continue from 7 to 8:30 p.m. Wednesdays for 17 weeks at a cost of $85 per person.
"How Much Do You Know About the Common Cold?" program: 7 p.m. Jan. 31, Peabody Institute Library of Danvers, 15 Sylvan St. For information: 978-774-0554; danverslibrary.org. The discussion will cover myths and facts about the common cold, and a Q&A session will be held afterward. The presenter will be Dr. Noemi Custodia-Lora, executive director of Northern Essex Community College Lawrence campus and community relations.
DanversCARES Family Workshop Series: 6-7:30 p.m. Feb. 6, Gordon Room, Peabody Institute Library, 15 Sylvan St., Danvers. Free. For information: Sheryl James, sheryljames@danvers.org; 978-335-3484. To register: https://bit.ly/2BLlMRc. The workshop series is geared to Danvers families with children ages 5-11. This session's topic is "Observing Your Child's Behavior."
Celebrate Recovery: 7-8:30 p.m. Mondays, 63 Jefferson Ave., Salem; noon–1:30 p.m. Fridays, 75 Lindal St., Danvers. For information: 617-803-4589. Celebrate Recovery is now holding free and open groups for anyone who would like to drop by. Celebrate Recovery is a Christian 12-step recovery program for hurts, habits and addictions.
Tai Chi: 10 a.m. Tuesdays for "Step by Step"; 9:30 a.m. Thursdays for "Beginner Foundations"; and 11 a.m. Tuesdays for "Intermediate Sword" at Tapley Memorial Hall, 13 Page St., Danvers. For information and to RSVP: 978-314-4264. Johanna Hattendorf leads tai chi classes — participants will strengthen joints, improve balance, breathing and concentration, and decrease stress.
Jump In Joint — Open Mic Night: 7-9 p.m. every third Wednesday, Tapley Memorial Hall, 13 Page St., Danvers. For information: 978-777-2711; dh.tremblay@outlook.com. This event is free and open to the public; attendees may perform or sit back and enjoy. Performers may bring an instrument, tell a story, tell some jokes, read a poem and more. No preregistration. Talent of all types is encouraged. Arrive by 7 p.m. to make the lineup.
Membership Matters: 6 p.m. every third Thursday, Tapley Memorial Hall, 13 Page St., Danvers. For information: 978-777-1666. Danvers Historical Society membership meeting.
Danvers Historical Society Speaker Series: 7 p.m. every third Thursday, Tapley Memorial Hall, 13 Page St., Danvers. Snow date: every fourth Thursday. For information: 978-777-1666. 2019 topics to be scheduled: Danvers firefighting, Irish immigrants of Danvers, remembering George Jacobs, comedy improv workshop, the Seasons of Glen Magna Farms, pre-colonial archaeology and redware pottery.
Veterans Social: 4:30–6:30 p.m. every Thursday, VFW Hall, 5 Conant St., Danvers. For information: 978-836-2395. All veterans and their families, regardless of military branch, dates of service or location of assignments are welcome. Food and drink are served; guest speakers will provide current information on important veteran-related issues.
Overeaters Anonymous: 7–8 p.m. Mondays at All Saints Episcopal Church, 46 Cherry St., Danvers. OA is a free, 12-step support group for people with eating disorders. For information: 781-641-2303.
Teen Book Corps: 3:30–5:30 p.m. third Mondays, Peabody Institute Library West Branch, 603 Lowell St. For information and registration: http://peabodylibrary.org. Middle and high school students are invited to join the Peabody Institute Library's new Teen Book Corps, a community service group for ages 11–18 whose mission is to spread a love of books and reading in the Peabody community. All meeting hours count toward community service requirements.
Multi-sensory music program—singing and signing: 10:30–11:15 a.m. first Wednesdays of each month, Peabody Institute Library South Branch, 78 Lynn St., Peabody. Registration required. For information: 978-531-3380; http://peabodylibrary.org.
The Northshoremen: 7:30–10:30 p.m. Wednesdays, Italian Community Center, 300 Rantoul St., Beverly. For information: 508-397-4444. Men of all ages invited to learn four-part harmony with The Northshoremen.
Open mic night: 8:30 p.m. Thursdays, Maple Street Tavern, 49 Maple St., Danvers. For information: facebook.com/pages/Maple-Street-Tavern/231976953487000.
Boy Scout Troop 50 meetings: 7–8:30 p.m. Thursdays, St. Mary of the Annunciation Parish Hall, 24 Conant St., Danvers. For information: 978-994-9555; troop50.georgetownboyscouts@gmail.com. Troop meetings have started for the new scouting year. Boys ages 10 and over may join, whether or not they have previously participated in Cub Scouts.
Danvers Community Access Television weekend classes: 9 a.m.-1 p.m. Saturdays, 87 Elm St., Danvers. For information: 978-777-2720. DCAT is open every Saturday. Area residents are invited to edit, tape shows or take classes.

redpajama_set_name: RedPajamaCommonCrawl


Get the Construction Dumpster Rental you need in Marysville, CA, for the price you deserve.
Our prices are some of the lowest you can find in Marysville, CA. Call today to see for yourself!
We offer many different sizes of dumpsters, and different sizes are available in different areas. Call us to find out availability in Marysville, CA.
Check below for cities and zip codes near Marysville, CA.
Need a Construction Dumpster Rental near Marysville, CA? Call Us For a Free Quote Now!
A good dumpster service will not make you stay waiting a very long time. They will begin any kind of challenge on the same day an individual contact them if you love. All you have to perform is produce that mobile phone call.
If you are inside the mood to get rid of all the rubbish that has bought out your car port and surface buildings, you must call a corporation that can get you a dumpster to rent the next day.
Garbage is always created from small scale ranges, which includes junk creation with homes and also extends to large scale garbage formation such as professional and construction waste. Properties require constant waste fingertips services while construction web sites require fingertips management through the job. Even though it would be sensible to get a long term dumpster for your home or even office where waste fingertips is foreseen to always occur, this would not be an ideal remedy for dealing with short-term industrial or even construction throw away. Dumpster rental would be the perfect solution for managing short-term industrial or even construction waste items.
Choose the sized dumpster to rent that you'll want for the job you may be doing or even are having completed.
To make life simpler, choose a dumpster which is on tires. You will be able to advance it easily if you need to when tearing roof shingles off from the front of the house towards the back of the house you are working on. Keep your shoppers happy with rapid service you may offer since you can easily get your estimate on the roof covering job, roof shingles and next day dumpster done in the flash. With the wonderful speedy service, you will preserve your customers really satisfied and with that word of mouth will continue to let the roofing organization thrive.
There are numerous sizes involving dumpsters of course as well as the company you end up picking will help you find the perfect just one. Regular dimensions include Forty yard, 25 yard, Something like 20 yard and also "minis" of 10 yard size. Proportions will vary likewise, so you have to ensure there's adequate space to the dumpster you choose. Some Construction Dumpster Rental in Marysville, CA companies likewise have those lightweight sanitation items that are great for special occasions or added restrooms if the home is having a comprehensive redevelopment.
Garbage and also rubbish removal is something that many of us overlook. We obtain the junk from various trash containers around home each week, go on it outside for collection, and forget about it. What happens, though, if you wish to get rid of not just a couple of bags at once? Or when you're conducting a project that may generate a large amount of non-standard trash spanning a week, or even two, or even three? In these cases, it may be worth your while to look into renting the dumpster from a rubbish remover in your town. You can find just one by looking for rental options in your city or location, such as "Construction Dumpster Rental in Marysville, CA MD" or even "Construction Dumpster Rental in Marysville, CA DC." These containers offer several positive aspects: you can put almost any trash inside them; you can use them for an extended period of your time; and you can depart the actual fingertips work to the actual junk removal services professionals. Read on to find out if renting a dumpster may well be a good move for your next household project or even cleanout.
Trash generation in Guam is actually inevitable since, it is made as part of regular hotel remodelling and modernizing of lodges according to shifting trends. Resort industry throughout Guam is dealing with serious poor effects because of to down turn in the travel related industry in the state. So as to with remain the competition and attract the particular limited number of consumers who visit their state, hotels in the market are at regular renovation. It's essential sign they try to keep the hotels clean and tidy simply by removing the crap on timely basis and upgrading the place with the state-of-the-art technology in respect to upcoming developments. These steps from the resort industry of Guam will produce huge tons of trash within the state and this trash provides to be got rid of effectively.
Whether it be renovating your property or building a new one, it is surely going to design your life much easier if you hire a company to help you with the particular garbage. How can this kind of service be considered a time and effort saving idea? Check out the following. You can do your backyard tidy up, work place garbage removal and much more with this particular service. Along with disposal can and dumpster upon rent now you can design your job of keeping the property or office clean less of a challenge.
By exploring the above educational tips, you should easily find an extraordinary company to rent overnight dumpsters for your building business.
And then there are the companies that happen to be so devoted to having a reduced base cost that they have to include fees for things like shipping and delivery, pick-up, weekend rates and so on.
When have you ordered something as well as put some thing to the side since you might use it one day? This stuff can be little, like deals, or huge like storage area boxes and even machinery as well as furniture. End keeping these products that you don't will need! You are only collecting trash! For high priced items, offer them on the internet or from the classified component of your local paper. When marketing things, restriction how long you are going to wait ahead of dropping your price and ways in which long you are going to keep the merchandise. Less expensive products can either go to charity as well as go right into the trash, dependant upon whether another individual could use them.
You can have your den renovated to fit regarding how you use it. If you want it bigger, get rid of a wall membrane as mentioned above. If you'd like it a lot more professional looking you might want to have wooden bookshelves installed. You may need a larger area which means that your clients can certainly sit a lot more comfortably. If you have more than one consumer from the very same business appear at a time, you will not want one person or maybe more sitting outside your family room in an additional room.
The 20 cubic yard dumpster is used for major building you may be performing on the most your house. The 20 cubic yard dumpster is equivalent to 10 pickup truck lots.
If you are excitedly planning on redesigning your kitchen than you have been occupied picking out brand-new kitchen cabinets, brand-new flooring, maybe new kitchen appliances and more. Together with your large cooking area remodeling job you will definitely will need to rent a dumpster to remove all of the dirt.
The larger the capacity of the rent a dumpster unit, the particular deeper they have an inclination to grow. For the reason that most companies employ a standard measured frame so the different pots can be carted around quickly. This can be a difficulty for people who order large dumpsters although need to get heavy components inside. If that's likely to be the case for you, be sure to request your rental comes with improvements for convenience, most depots shouldn't have any trouble producing suitable modifications as long you actually let them know things you need.
Many people will go their entire lifestyles without previously needing to end up in Construction Dumpster Rental in Marysville, CA. Others may well do it each and every day. But for those in between, it may seem like somewhat of a labyrinth when deciding the way to go about it. Perhaps you have a huge function in the setting up and need a method to dispose of all the trash. You will be planning a massive demolition and need a quick place to shop debris without having to take countless trips to the dump. Whatever the reason, you can find people that will let you get exactly what you need. Below are some hints that might help you get started.
There are amount of Construction Dumpster Rental in Marysville, CA companies out there who can help you in this respect. This is the most economical way of eliminating huge numerous piled up rubbish in the shortest time feasible. Dumpster rental companies distribute across the market will be equipped with wide verities regarding dumpsters to suit your exclusive requirements, although a throw off dumpster is a best option to remove the trash in community tidy up.
As of The new year, televisions, computers, laptops in addition to monitors usually are banned in the garbage in accordance with Brand new Jersey's Electronic Spend Management React (Act).
Community cleanups have gotten more and more popular as the citizens carry back their local neighborhoods one road at a time. Affordable dumpster can be shipped the very next day. The neighbors all enjoy participating in a tidy up day that includes construction dumpster rental fees. Keep large trash for example furniture from the sidewalks as it waits intended for trash pick-up and obtain the lawns sparkling clean up by using a Construction Dumpster Rental in Marysville, CA. Renting a dumpster gives the community with each other and eliminates excess rubbish quickly and easily. Everybody can throw away the surplus that has hemorrhoids up all-around their homes, streets, etc in a easily rented and shipped dumpster. There is no need to bag the items staying disposed and so a dumpster helps make trash discretion and tidy up day or week easy for everyone. Keep your neighborhood rubbish free by having a community tidy up day. Some sort of construction Construction Dumpster Rental in Marysville, CA will make your project well-known and quick; everyone will probably be happy to engage.
When you rent a dumpster look for built to be on tires to make the job much easier to suit your needs and/or your specialist hired to get the job done.
The larger the total capacity of the rent the dumpster unit, the deeper they have a tendency to grow. The reason being most companies work with a standard size frame so your different bins can be carted about around effortlessly. This can be a dilemma for people who purchase large dumpsters yet need to obtain heavy materials inside. If that is likely to be the case for you, be sure to request your rental comes with improvements for convenience, most depots should not have any trouble producing suitable alterations as long you actually let them know what you need.
Many people will go their entire life without at any time needing to enter Construction Dumpster Rental in Marysville, CA. Others might do it each and every day. But for those invoved with between, it could seem like a labyrinth when deciding the way to go about it. Perhaps you have a huge affair in the organizing and need an easy method to dispose of every one of the trash. You will be planning a major demolition and need a rapid place to retail store debris without taking countless visits to the eliminate. Whatever the reason, you can find people that can assist you get just the thing you need. Here are a few hints that can help you get started out.
There are quantity of Construction Dumpster Rental in Marysville, CA companies in the market who can direct you towards this value. This is the most inexpensive way of eliminating huge numerous piled up rubbish in the quickest time achievable. Dumpster rental companies pass on across the industry will be designed with wide verities of dumpsters to suit your special requirements, yet a spin off dumpster might be a best option to dispose the trash about community cleaning.
As of 2011, televisions, computer systems, laptops along with monitors usually are banned from the garbage in accordance with Brand new Jersey's Electronic Squander Management React (Act).
Local community cleanups are getting to be more and more popular because the citizens acquire back their local communities one neighborhood at a time. Inexpensive dumpster can be delivered the very next day. This neighbors just about all enjoy involved in a cleaning day which includes construction dumpster renting. Keep significant trash for instance furniture away from the sidewalks even though it waits regarding trash pick-up and acquire the meters sparkling clean up by using a Construction Dumpster Rental in Marysville, CA. Renting a dumpster brings the community jointly and removes excess rubbish quickly and easily. Anyone can throw away the extra that has loads up around their homes, streets, etc in a single easily booked and delivered dumpster. There is no need to carrier the items staying disposed thus a dumpster creates trash convenience and cleaning day or maybe week easy for everyone. Maintain your neighborhood rubbish free by having a community cleaning day. Some sort of construction Construction Dumpster Rental in Marysville, CA can certainly make your project common and rapid; everyone are going to be happy to be involved.
When you rent the dumpster look for engineered to be on added wheels to make the work much easier for you and/or your contractor hired to get the job done.


Last week I posted about what I've done related to mesh simplification. The models shown on the following examples are lighter versions resulting from that, running more smoothly on my phone.
Navigating the scene: 1-finger orbit, 2-finger pan and pinch for zoom.
I couldn't thank my mentors Steffi and Ian enough for their help, advice and patience!
I'm also really grateful to OSRF for choosing me and to GNOME for organizing the program.
All the code of Gzweb Mobile can be found here and the wiki page about it here.


text:
Marco Kerstens
If you've got good ideas, you can do what you like here.
When I was 19, pretty much straight after I'd passed my secondary school exams (HAVO), I started in IT. I worked at an IT company where I gained a basic knowledge and learnt to program. Soon after that, I started work at Nationale-Nederlanden. I've been here around ten years now. First I worked in testing, but quickly I was able to progress my career – something that I'd always intended to do and what's also made possible here – and I started to develop and manage applications.
I work on development and operations in a cloud environment. To do that, I learnt to work with .NET, a framework for seamless cooperation between applications. Working in the cloud, however, is very different from how we used to work here. Then, we had a lot of data centres at Nationale-Nederlanden. To get the information you needed for your work, you had to go through complicated and lengthy processes. But now, in a cloud environment, you can work with the latest technology and access resources in no time. As a result, I can come up with new applications in a day and know that they work. Nationale-Nederlanden gives us the rights and the confidence to work in the cloud and to do great things.
On a typical working day, I deal with a variety of issues. For example, I check whether the systems have been running properly overnight. I can then see what needs to happen on the sprint backlog. This could be anything: from developing a new functionality to getting stalled processes up and running again.
We recently found an application that had been written in Clipper. This is an old programming language that was used a lot to make programs under the DOS operating system. The language was mostly used to make database programs. Hardly anybody is familiar with Clipper these days. The language doesn't work on Windows 10. So, we converted the application, in continuous interaction with and feedback from the users.
Initially, you can get a bit despondent working with such an old language, but after we'd asked the users what they did with the application, we started deliberating, grappling, testing and building. Suddenly, we had something! We took it to the users. It didn't look that great to begin with, but they were incredibly enthusiastic, because the application was much better than they were used to. We then discovered that we could use Bootstrap for this application. Bootstrap is an open source with tools for websites, such as typography, forms and buttons. Suddenly, the interface looked much better. Yes, you really do have the scope here to develop applications and that makes me very happy.
And there are lots more challenges we can embrace if we have the right IT programmers in house. For them, Nationale-Nederlanden is an exciting and inspiring environment. Because if you've got good ideas, you're given all the scope and freedom to carry them out. You see, at Nationale-Nederlanden, we make sure that people don't need to worry. That's our strength and it will stay that way. But IT does play a very dominant role in this.
IT Engineer Nationale-Nederlanden Non-life & Income
Show all people


Fractures are broken bones. They can occur during athletic activity, be the result of a fall, or a traumatic accident. Fractures also occur as a result of conditions that weaken bones, such as osteoporosis. The severity of the fracture depends on the type and location of the break.
Diabetes—People with diabetes have an increased risk of foot ulcers and neuropathy, a serious condition in which nerve function is reduced, creating less sensation. Neuropathy may also cause a chronic burning or tingling sensation.
When a cause cannot be determined, any pain in the ball of the foot is generally referred to as metatarsalgia. It is most likely caused by poor footwear or by high-impact activities. People with a high arched foot are more likely to develop metatarsalgia.


text:
E - Klasse 6 - Arbeit Nr. 3 - GreenButterSolutions
ENGLISCH > ARBEITEN > Klasse 6
a prisoner in the US
1. Reading comprehension. Answer the questions below in complete sentences.
A true story?
While my friend, George, was reading in bed, two thieves climbed into his kitchen.
After they had entered the house, they went into the dining-room. It was very dark, so they turned on a torch.
Suddenly, they heard a voice behind them. "What's up?
What's up?" someone called. The thieves dropped the torch and ran away as quickly as they could.
George heard the noise and came downstairs quickly. He turned on the light, but he couldn't see anyone. The thieves had already gone.
But George's parrot, Harry, was still there. "What's up, George?" he called.
"Nothing, Harry," George said and smiled. "Go back to sleep."
1.1. Who tells the story?
1.2. When did this story happen?
1.3. What was George doing when the thieves climbed into the kitchen?
1.4. Where did the thieves go after they had entered the house?
1.5. Why did they use a torch?
1.6. What didn't they know?
1.7. What was so special about George's parrot?
1.8. What was his name?
1.9. What did Harry do?
1.10. What did the thieves do then?
1.11. Why did George come downstairs?
1.12. Why couldn't he see anyone?
1.13. How did George know that thieves had been in the house?
2. Tell the story above to a friend. Use your own words. Do not write more than 45 words.


2-pole induction continuous rated motor with squirrel cage rotor. Stator insulation class 'H' (180ºC).
The rotor shaft is carried in two single row, deep groove ball bearings. The bearings are enclosed with high temperature grease-containing special Anti-corrosion additive.
Waterproof/oil proof, rubber-insulated, neoprene-sheathed copper conductor flexible cable, 50ft. (15m) length standard. Type SOOW in North America, EPR in the Middle East and HO7RN in the EU. 6 Core with thermal overloads optional.
Tandem Tungsten Carbide/Tungsten Carbide and Tungsten Carbide/Tungsten Carbide Mechanical seals wholly enclosed in a pressure compensated oil chamber.
Nitrile Rubber– Lined Diffuser. Polyurethane Optional.
Nitride Hardened 410SS to 56HRC is Standard.


text:
15 Surpising Celebs Who Got Married In Secret Without Telling Anyone
by Kaye L
Getting married should be one of the most exciting, joyous times in anyone's life. It's a time for family and friends to come together to celebrate the love that two people have for one another. That's if you're a normal person. For celebrities, it's slightly different. It's more about how two famous people can get married and actually make the moment about them and not about ducking and diving the paparazzi. In order to do this, a lot of celebrities have opted to get married in secret. Normally, a move like this would be rare but more and more of the rich and famous are trying to keep their privacy and hide as much of their personal information as possible. So, sure, they duped their fans a bit by not allowing them to experience their intimate moments, but we are just going to have to suck it up. They can't give us all of themselves all the time. So, the least we can do as fans and supporters is allow them to have their wedding to themselves. Who are we kidding? We would have much rather been in the loop the entire time. The good thing is that some of these couples shared intimate details about their marriage with us after it happened but, of course, some of them are still holding out on us. It seems like the secret marriage is the new thing in Hollywood and we are all just going to have to get used to it. Here are just a few of those celebrities that left their fans out of their wedding plans.
15 Benji Madden & Cameron Diaz
via glamour.com
This couple had a small wedding, but it was still star-studded and a classic Hollywood affair. The actress had a lot of her close, famous friends take part in her wedding and show up as guests to support their girl. Nicole Richie, who introduced her to Benji Madden, and Drew Barrymore served as bridesmaids. Some of the famous guests were Lionel Richie, who surprised the couple with a serenade on their special day. Gwyneth Paltrow, Toni Collette, and Judd Apatow cheered them on and Ryan Admas provided music all night long. So, as you can see, it was a secret, but it was also meaningful and intimate to the couple. She describes her new family as a strong support system because they are such a close-knit family. She waited till she was 41 to get married and she seems quite happy with the decision.
14 Jason Momoa & Lisa Bonet
via torontosun.com
These two have to be one of the cutest couples in Hollywood. For a long time, they were just boyfriend and girlfriend until one day it was "leaked" that they were actually married. In early October of 2017, the couple tied the knot in front of a small group of friends and family. While Momoa was making the media rounds for Justice League, he expressed how annoyed he was about his business being out in the streets saying, "I thought it would have stayed that way" but that some jerk online "leaked it" and "I will find you." He went on to say, "You know what, I've been married to my wife for 12 years, it's just a gathering of our families and celebrating our love." We certainly feel sorry for whoever leaked that information. Aquaman may put hands on them.
13 Amy Schumer & Chris Fischer
via E! Online
One day, Amy Schumer wasn't married, and the next day, she was. No one even knew she had a man. As of February 13, she is a Mrs. We don't know much but what we do know is the wedding took place in Malibu at a rented home. Jennifer Lawrence, Larry David, and Jennifer Aniston were among the guests. A no-photo policy was reportedly enforced. She officially announced her nuptials on Instagram a few days later. She still hasn't commented on her marriage and she probably never will. The funny girl is acting super funny towards her fans. All we want are a few pictures Amy, come on. How can you go from going on a few dates to getting married and leaving us out of the loop?
12 Rachel Weisz & Daniel Craig
via Radar Online
Rachel Weisz and Daniel Craig are notoriously private. Fans didn't even know that were dating when they secretly tied the knot in 2011. The couple met on the set of their film, Dream House, and began a relationship almost immediately. They got married the same year the film was released. At first, people thought it was a rumor but then the couple sort of confirmed their relationship by walking hand and hand down the red carpet. They got married in a small ceremony in New York but had only four people in attendance. Her son, his daughter, and probably two adult friends who stood in as best man and bridesmaid. Ever since they got married, they have been super low-key about their love. Maybe this is the secret to keeping their relationship intact.
11 Leighton Meester & Adam Brody
These two made many teen drama fans dreams come true when they hooked up and became the cutest couple to come out of a television drama. They shocked the world by having a child and then they shocked us when they secretly got married in early 2014. The couple never publicly talks about their marriage or their kid. At a time, they even avoided being seen together in an effort to keep their relationship their own. This is expected by Meester, who has had a few scandals attached to her name in the past thanks to her money-hungry mom. She was probably so sick of being the topic of people's conversation. She and Brody make the cutest couple ever and while we don't know anything about their wedding, we can only assume it was low-key, small and beautiful.
10 Mila Kunis & Ashton Kutcher
via NY Daily News
Mila Kunis and Ashton Kutcher have certainly been very quiet about their relationship. In addition to having two kids that they are super secretive about, they got married and told no one about it. The only reason why fans can speculate that the couple is married is that during an interview on the Late Late Show, she was asked about her marriage and, while she didn't confirm, she couldn't stop smiling. However, on the Ellen Show, Ellen Degeneres managed to get a little bit of information out of Kutcher. He said that pulling the secret wedding off took strategizing, "We really didn't want helicopters at our wedding." Fans now know that they got married on July 4th weekend but pretended for months beforehand that they were already married. They certainly jumped through hoops to keep their secret.
9 Mary-Kate Olsen & Olivier Sarkozy
via Popsugar
There isn't much that we know about Mary-Kate Olsen and Olivier Sarkozy's relationship, period. So, of course, their wedding is straight out of a Mary-Kate and Asley Olsen Mystery novel. But, here is what we do know. It had about 50 guests, it was possibly on Thanksgiving weekend, in New York for sure (they both live there). One thing we know for sure is that every guest had to surrender their phones at the door which is why there are absolutely no public photos. The couple got engaged in 2014, which shocked everyone, especially her young fans because of the 20-year difference between the two. One factual detail that came from their wedding was reported by the New York Post, they stated that the couple had out "bowls and bowls full of cigarettes."
8 Kristen Bell & Dax Shepard
We know that they were married in 2013, but neither Kristen Bell or Dax Shepard is willing to discuss any details of their wedding. This comes as no surprise to anyone because they don't discuss anything about their lives. They graced fans with a picture of them, signing what looked to be a marriage license with no one else around. It was at the Beverly Hills courthouse in a small room. Bell told the press, "It was still one of the best days of my life." She also added that there was no family or friends just them, the judge, and their vows. They now have two kids and are still super hush about their life, in fact, even more now that they have children.
7 Margot Robbie & Tom Ackerley
via Fame Focus
Margot Robbie and Tom Ackerley are barely seen together in public. No one knew they were even dating until she sort of announced her marriage on Instagram. They have supposedly been together since 2013 and got married in 2016. Robbie was regularly asked if she was married or engaged to her long-term boyfriend and she quickly shut down the rumors every time. She was quoted by Extra saying, "I can't even get a day off at the moment, so that stuff's gonna have to wait." All of a sudden, a few months later, she was married (well, rumor had it at least). Of course, we don't know anything about her wedding day except that it was in her native country Australia. A private ceremony in Byron Bay to be exact. She is quite family oriented so we can only assume that she kept the ceremony family only.
6 Amanda Seyfried & Thomas Sadoski
via Entertainment Tonight
This couple met in 2015 on the set of a play, The Way We Get By. They got engaged in 2016 and then very soon after they were married. Seyfried described it as a marriage on a whim, "We just took off into the country with an officiant, just the two of us, and we did our thing." So, they kept it really private, no family and no friends just the two lovebirds. Thomas Sadoski told James Corden on The Late Late Show with James Corden, "we had a great day. It was perfect." In March 2017, he also announced that the couple was expecting their first child together. Even after their wedding, they kept it low-key and walked through the neighborhood with their puppy. Then, they had dinner.
5 Blake Lively & Ryan Reynolds
via: Elle
Blake Lively and Ryan Reynolds allowed Martha Stewart Weddings to feature their wedding, but they told only a handful of people they were getting married. We know the couple got married in Charleston and we know the bride had a Marchesa gown, which apparently not even the magazine was able to get great pictures of. Lively and Reynolds have always been very private about their life together— no one even knew they were dating for as long as they were. Fans never hear about their kids or their love story, which is weird because they seem so open and honest on social media, with Reynolds making jokes about his children and parenting style. Yet, they still manage to be notoriously private. It's working for them, so we can't really complain.
4 Ellen Page & Emma Portner
Ellen Page and Emma Portner tied the knot in early 2018 and in a very unnatural, public move for the couple, they announced it on social media. "Can't believe I get to call this extraordinary woman my wife," said Page as she introduced the world to her wife, Emma Portner, a teacher at a Broadway dance academy. Portner echoed the message on her Instagram page. The couple also shared a picture of their wedding bands. It isn't known how long they have been a couple because Page only started posting photos of her partner earlier that summer. The duo seems genuinely happy and after their announcement, they went back to being the low-key, quiet couple that their fans are used to. We aren't sure what's next for this couple, but we hope it's babies.
3 Adele & Simon Konecki
Adele showed up to the Grammys with a ring on her finger and the world went crazy. She supposedly had a small, intimate affair with mainly friends and family, oh, and Robbie Williams. The wedding also included Konecki's 10-year-old daughter and Adele's mother, Penny. It was supposedly held at their home in order to keep it secret and intimate. It was very non-traditional, in fact, the only traditional part of the wedding was Adele's white dress. That was one thing she insists on having. It has been reported that the couple always wanted to have a ceremony to show their love, but they just kept putting it off. We don't know if we would pick Konecki for Adele, but we do know that he better treat her right because her fans are loyal.
2 Kerry Washington & Nnamdi Asomugha
via an24.net
Kerry Washington and Nnamdi Asomugha are the definitions of private. They never talk about their relationship or their kids. They barely even walk the red carpet together unless it is a super prestigious event. Even then they don't walk the actual carpet together, they show up separately and, sometimes, don't even sit with one another. Washington hasn't ever talked about her love story and we have come to terms with the fact that she probably never will. Fans still don't know when the couple met or when they got engaged or even what Washington's wedding ring looks like. The most information we could gather was they got married in Oklahoma, apparently. Some magazines have been quoted saying that their wedding was "simple and sweet" but, we aren't sure how they know that, seeing as Washington and her man are tight-lipped on everything.
1 RuPaul & Georges LeBar
via Hellomagazine.com
RuPaul and Georges LeBar have been together for over 20 years. Fans had just assumed that they would end up keeping their relationship common law. After so many years, couples normally don't get married, so what's the point, right? For RuPaul and his long-term partner, it was apparently something that they wanted to get around to. They were secretly married in March 2017. RuPaul got candid on Hollywood Today Live saying, "We got married on our 23rd [anniversary]. I met him on the dance floor at Limelight in 1994, on his birthday. So we got married on his birthday, the anniversary of when we met, this year." This couple was built to last and whether they cemented it with marriage or not they would still be together.
References: USAToday.com, ETOnline.com, Elle.com, HarpersBazaar.com, VanityFair.com, People.com, Mirror.co.uk, EOnline.com
More in Pop Culture
10 Rules Taylor Swift Followed To Achieve Success
10 Things Jennifer Lawrence Does To Achieve Success
Every Cast Member Of The Good Place's Net Worth
The Cryptocurrency Craze: 10 Celebs Who Have Backed Bitcoin
The Net Worth Of The Cast Of Harry Potter
Every Cast Member Of Supernatural's Net Worth
8 Ridiculously Expensive Things Keanu Reeves Has Bought
Net Worth Of The Cast And Crew Of Family Guy
Lead Singers Who Are Loaded: 10 Famous Frontmen Who Are Worth $100 Million Or More
10 Crazy Expensive Things Mariah Carey Has Bought
Long Live The Queen: The Net Worth Of The Queen & The Royal Family
Net Worth Of The Kennedys (Including Arnold Schwarzenegger & Maria Shriver)
10 Simple Ideas That Made People Millionaires
Every Cast Member Of Sons Of Anarchy's Net Worth
10 Of The World's Most Expensive Parking Spots, Ranked