One of the main impediments to making electric vehicles (EVs) a viable option for mainstream adoption continues to be the weight of batteries. Even with next-generation li-ion cells like those used in Tesla vehicles, it’s very difficult and expensive to get enough juice packed into such a small space. Volvo has been toying with EVs for a few years now, but the Swedish auto manufacturer has just announced a potentially revolutionary approach to designing electric vehicles. Volvo wants to replace some of the steel body panels in its cars with carbon fiber composite materials that can store power like a battery.
Using a standard Volvo S80 as a test platform, the company replaced the trunk lid, door panels, and hood with this new material. The rechargeable panels are composed of multiple layers of carbon fiber, which are insulated from each other by fiberglass inserts. The layers of polymer-infused carbon fiber are actually acting as the cathode and anode in this system with super capacitors built into the skin. The result is a structural component that can be charged like the battery in any other EV, either with regenerative braking or by plugging the vehicle into the power grid.
Because the battery panels in this test care are replacing heavy structural components while doing away with the centralized battery, the total weight is reduced dramatically. Volvo estimates that replacing an EV’s entire power system with battery-infused panels like this would reduce the weight by 15%. To put that in context, Tesla’s entry-level battery pack weighs over 1,000 pounds. Perhaps even more importantly, the weight will be evenly distributed to allow for better handling and less engineering hassle.
Beyond the realm of fully electric vehicles, even replacing a few parts of conventional cars could do away with the need for heavy 12-volt batteries that power the starter, lights, and other components. In the middle ground, hybrid vehicles could also benefit from rechargeable paneling.
This approach to powering EVs is not without its drawbacks, though. While carbon fiber is very strong, some parts of a car are designed to collapse in the event of an accident. By absorbing some of the energy from impact, the crumple zones can protect your squishy human body from the worst of it. That means more damage to the power paneling in places like the hood and trunk, which will be expensive to repair. Emergency crews could also face a new challenge trying to rescue people from such a vehicle after a crash — they would essentially be trying to fish someone out of a giant damaged battery.
Volvo didn’t say when it might use the nanomaterial in a production vehicle, but was keen to point out the sustainability of such an approach. If Volvo does put structural batteries into production, it will need to work on lowering the cost of carbon fiber, which is still quite high.