A battery without mass! The future of electric vehicles and airplanes?

Scientists have recently developed a new type of structural battery that is ten times more efficient than previous prototypes. Unlike conventional batteries, this innovation not only stores energy, but also acts as part of the physical framework of a vehicle or device.

Structural batteries are often called “massless energy storage” because they are built directly into the body of a car, aircraft or even electronic device. This reduces the overall weight while increasing the strength of the structure. Researchers from Chalmers University of Technology and the Royal Institute of Technology in Sweden have shown how their latest design achieves record-breaking results.

The battery was made by inserting glass fibers between the electrodes, adding a polymer electrolyte, and hardening the cell in a furnace. The result is a flat battery that conducts electricity well and can withstand mechanical loads in all directions.

The prototype currently achieves an energy density of 24 Wh/kg, which is about 20 percent of the capacity of today's lithium-ion batteries, but with significantly higher safety and a stiffness of 25 GPa. Because the vehicles are lighter, they require less energy to drive, which compensates for the lower density.

The next steps include replacing aluminum with carbon fiber and thinning the separator. This could allow the battery to reach 75 Wh/kg and a stiffness of 75 GPa, putting it on par with many building materials while storing more energy.

The applications are not limited to electric cars, but also to e-bikes, satellites, laptops and especially aircraft, where weight is the biggest obstacle to electrification. Scientists even imagine a combination of such batteries with solar cells, which would allow the captured energy to be stored for later use.