Summary
- Researchers at Chalmers University in Sweden are developing massless EV batteries using carbon fiber
- Removing the battery could increase range by 70% but the battery is designed to be a working part of the vehicle structure
- The team reported an energy density of 24 Wh/kg in 2021, with a goal of achieving 75 GPa stiffness
- The researchers are also working on a follow-up project to improve the battery’s performance
- Massless EV batteries are part of a broader sustainability movement in the auto industry with a focus on eliminating cobalt and manganese in batteries
Article
Research is underway at Chalmers University in Sweden to develop massless EV batteries, which could potentially increase range by 70%. The key ingredient in these batteries is carbon fiber, a lightweight and tough material that can also serve as a structural element in the vehicle. By using carbon fiber as a conductor, the need for copper or aluminum current collectors in a typical EV battery can be eliminated, leading to significant weight savings. The goal is to reduce the overall weight of the vehicle, improve range per kWh of battery pack installed, enhance handling, and simplify vehicle assembly, thereby reducing costs.
The research team achieved a major milestone in 2021 with the development of a massless EV battery that demonstrated 10 times the multi-tasking performance of previous iterations. While the energy density of these batteries was lower compared to typical Li-ion EV batteries, the weight of the vehicle could be greatly reduced, leading to less energy consumption and increased safety. With a stiffness of 25 GPa, the structural battery could compete with other commonly used construction materials. The ultimate goal is to reach 75 GPa to make massless EV batteries much lighter than aluminum but just as tough.
In a follow-up project funded by the Swedish National Space Agency, the researchers replaced aluminum foil in the cathode with carbon fiber, coated with the LFP formula. This new design achieved a stiffness of 70 GPa, matching the performance of aluminum with a lower weight. The energy density measured 30 Wh/kg, indicating progress but still falling short of Li-ion batteries. Despite the lower energy density, the researchers believe that commercial-ready massless EV batteries could offer lighter weight and improved structural capabilities for vehicles.
The pursuit of massless EV batteries is part of a broader shift towards sustainability in the automotive and energy storage industries. By using the LFP formula and semi-solid electrolytes instead of cobalt and manganese in conventional Li-ion batteries, researchers are working to address supply chain issues and enhance safety. However, carbon fiber production poses sustainability challenges due to its energy-intensive manufacturing process and lack of recyclability. Solutions such as recyclable carbon fiber composites developed by organizations like the US Department of Energy’s National Renewable Energy Laboratory are being explored to mitigate these issues.
As the development of massless EV batteries advances, the potential for longer driving ranges, reduced energy consumption, and increased safety in electric vehicles becomes more promising. The research at Chalmers University highlights the importance of investing in light and energy-efficient vehicles to drive the cleantech revolution forward. By combining structural elements with battery functions, massless EV batteries could revolutionize the electric vehicle industry and contribute to a more sustainable future for transportation.
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