Battery researchers are continually experimenting with alternative materials in an effort to boost performance, and a group from Stanford University and SLAC National Accelerator Laboratory is claiming to have landed on a winner. The team has redesigned the current collector component of lithium-ion batteries in a way that greatly reduces their weight, making them not only more efficient but also more resistant to fires.

Lithium-ion batteries feature a pair of current collectors, which work with the device’s two electrodes to distribute the current flowing in either direction. Today’s current collectors are typically made from sheets of copper or aluminum foil, which makes them one of the battery’s heaviest components, sometimes accounting for as much as 50 percent of the overall weight of the device.

Therefore, considerable performance improvements are to be gained by making these components and in turn the batteries themselves, lighter. This would enable them to store more energy per unit of weight, which would reduce the load an electrical vehicle has to carry with it, for example, allowing them to travel farther on each charge.

Previous approaches to this problem have involved tweaking current collectors to make them more porous or thin, as a way of cutting weight. But these have led to batteries that are more fragile, are chemically unstable or need to be compensated for by adding more electrolyte material, which makes them more costly.

The team from Stanford University and SLAC National Accelerator Laboratory were experimenting with another material entirely, a lightweight polymer called polymide. This was integrated with a fire retardant called triphenyl phosphate, or TPP, with the material then coated on either side with a very thin sheet of copper.