Swedish university makes breakthrough in “massless” battery technology

Researchers at Chalmers University of Technology have developed a structural battery that performs ten times better than previous versions. The battery uses carbon fiber as a conductor and load-bearing material, making it possible to store energy while supporting the structure of electric vehicles, for example.

The technology is called “massless” energy storage because the weight of the battery effectively disappears when it becomes part of the structure.

Today’s electric cars carry large batteries that do not contribute to the structure of the vehicle, but a structural battery can change that by being both a power source and part of the vehicle’s body.

– Previous attempts to make structural batteries have resulted in either good mechanical properties or good electrical properties, but here we have succeeded in creating a battery with competitive energy storage and stiffness, explains Leif Asp, professor at Chalmers and leader of the project.

The battery has an energy density of 24 Wh/kg, which is about 20% of the capacity of standard lithium-ion batteries. However, vehicles with structural batteries weigh much less, which means they require less energy to run. In addition, the lower energy density of the battery offers increased safety. The current model has a stiffness of 25 GPa, making it comparable to many construction materials.

“Only limited by our imagination”

Chalmers researchers are now working on a new project, funded by the Swedish Space Agency, where the goal is to further increase the battery’s performance.

– The next generation of structural batteries holds immense potential. It is entirely feasible to produce smartphones, laptops and electric bicycles that are half weight of current models, says Leif Asp.

The goal is to achieve an energy density of 75 Wh/kg and a stiffness of 75 GPa, which would make the battery as strong as aluminum but significantly lighter.

Asp also sees potential for this technology in future electric cars, aircraft and satellites.

– We are really only limited by our imagination. There is a huge interest in these lightweight, multifunctional materials, he concludes.