Manufacturing Electric Vehicles with Recycled Materials
Recycled materials have been used in cars for over a decade now, but mostly in out-of-sight places, like under the bonnet components. And they have always represented a very low proportion of total vehicle weight.
As recycled material quality has improved, there’s been a recent growth in the use of recycled materials in more visible areas of the car, especially in vehicle interiors. Several electric vehicle (EV) manufacturers have been leading this charge.
What’s Behind the Drive to Use Recycled Materials?
Car manufacturers are under pressure to make their vehicles less environmentally impactful. EVs are ahead of the curve, and so it’s natural that recycled materials would be used more extensively in EVs than in conventional vehicles.
Recycling materials use less energy and water compared to creating new (virgin) materials, and it creates fewer emissions. In many cases, it also prevents the physical environmental damage from extracting raw materials from the earth’s surface or under the seas.
From a marketing perspective, the majority of potential buyers want an EV because it represents an environmentally friendlier individual transport option than a conventional vehicle. These customers would, therefore, be more interested in other sustainable vehicle features. Manufacturers hope that the use of recycled materials may help buyers to choose one make over another.
Companies Leading the Recycling Charge
Nissan’s Green Program seeks to eliminate all waste throughout a vehicle’s life, from design through to disposal. By weight, almost 25 percent of the Nissan Leaf is manufactured from recycled materials. Old PET soda bottles are recycled to make the seats, recycled fabrics are used in the sound insulator pads under the hood, and parts from old electrical appliances are used in the center console. Resin from recycled plastics are even used to make larger plastic components for the Leaf, such as the dash and door parts.
Some of the BMW i3’s greenest features don’t utilize recycled materials, but instead, consider the environmental impact of the manufacturing process. Rather than using formaldehyde or other chemicals to tan their leather seats, BMW uses olive leaves. Panels on the doors and dash are made from renewable natural fibers like open-pore eucalyptus that’s been certified by the Forest Stewardship Council (FSC).
The Prius uses bio-plastics in their seat cushion design, and in several other parts throughout the interior.
Kia Soul EV
Like the Prius, rather than using recycled plastics, the Kia Soul EV makes the use of bio-plastics to make 10 different interior parts; from the door panels to the seat trims and the carpets. This organic material amounts to nearly 53 pounds per vehicle.
Can Recycled Materials Make EVs More Energy Efficient?
Electric vehicle manufacturers all have one major target when designing new models; increasing their energy efficiency so that they can increase their range. One of the key factors to consider is, therefore, the weight of the vehicle. The lighter it is, the less energy it requires to move it forward.
This must be balanced against improved safety standards. Since around 1990, conventional cars have actually been increasing in mass by around 8kg per year, for this very reason.
As a result, EV manufacturers are on the quest for lighter non-structural materials. In some instances, recycled materials are able to provide them with the solution, at the same time as having a lower manufacturing carbon footprint.
Some newly developed recycled materials are lighter than their alternatives, helping to bring down total vehicle weight. UK manufacturers Luxus have developed a new material, Hycolene, used to make interior parts that are between 10 and 12 percent lighter compared to their virgin plastic equivalents.
Another company, Benecke-Kaliko, uses TEPEO, an interior foil that is up to 50 percent lighter than PVC. This material can bring the weight of a car down by as much as 2kg and produces 48 percent less CO2 over its entire lifecycle compared with conventional PVC foil.
Other Environmental Considerations in EV Design
Material Recycling During Manufacture
A problem with recycling car parts, especially metals, at their end of life is scrap contamination; due to contamination with other materials, the metals are not considered pure enough to be recycled to make new structural car parts.
However, during the manufacturing process, there is the opportunity for structural car materials to feed into the recycling supply chain. In a controlled factory environment, recycled material quality can be maintained and scrap contamination can be a much lesser problem.
For an example of the amount of material that could be available to feed into the recycling supply chain, only about a half of the sheet metal used to make a car door actually ends up in the car, with the rest wasted. In a partnership between Jaguar Land Rover (JLR) and the aluminum manufacturer Novelis, 30,000 tons of press shop aluminum scrap were recovered from JLR plants and recycled by Novelis, to be incorporated into new body panels.
The alternative is to sell scrap steel to other industries where safety standards are lower, and there’s less of a problem with scrap contamination. For example, General Motors sells scrap steel from its manufacturing process to Blue Star Steel. Blue Star reprocess this steel to make components in heating and air conditioning equipment.
Lower Embodied GHG Emissions
As well as searching for new materials that can be made from recycled products, EV manufacturers can also make significant environmental savings from selecting raw materials that produce less carbon and GHG emissions in their manufacture.
This is the reasoning behind the use of bioplastics, woods sourced from sustainable forests, and in the case of BMW, carbon fiber that is produced using only hydroelectric power.
Lightweight Materials in Structural Components
The use of lightweight materials and multi-material components in car manufacturing has helped to produce lighter, more sustainable vehicles. For conventional vehicles, this has resulted in a significant reduction in CO2 emissions during vehicle use phase, helping them to achieve stricter vehicle emission standards. For EVs, it has helped to increase their mileage range.
Vehicle End of Life
While reaching all of their other safety and environmental objectives, EV manufacturers mustn’t lose sight of the need to make materials easier to recover and recycle or reuse at the end of the vehicle’s life.
The problem is that some of the joining techniques that fuse multiple materials together to make vehicles lighter can present serious challenges at the end of life. The ability to recover these materials in a closed-loop is severely limited. With new car design using more and more of these multi-material components, this is a growing concern.
Even better than finding opportunities to recycle components from end of life vehicles is reuse them. Toyota has found one such opportunity at Yellowstone National Park, where more than 200 hybrid batteries have been used to form a stationary storage unit that holds electricity generated by the park’s array of solar panels. With a combined capacity of 85kWh, they supply the power required by the buildings on the Lamar Buffalo Ranch campus.
Recycled materials represent an important, and growing part of EV manufacturers’ plans to improve vehicle sustainability. But they must be considered holistically alongside other elements of vehicle design to ensure true environmental savings.