Electrolyte additives prevent fires in next-generation lithium batteries

June 18, 2015 // By Paul Buckley
Researchers at SLAC National Accelerator Laboratory and Stanford University have discovered that adding two chemicals to the electrolyte of a lithium metal battery prevents the formation of dendrites which could cause the battery to short out, overheat and catch fire.

The findings, published in Nature Communications, could help remove a major barrier to developing lithium-sulfur and lithium-air batteries, promising future
technologies that could store up to 10 times more energy per weight than batteries now used in consumer electronics and electric cars.

"Because these batteries would be much lighter than today's rechargeable batteries, they have a lot of potential for extended-range electric vehicles," explained Yi Cui, an associate professor at Stanford University and the Dept. of Energy (DOE)'s SLAC National Accelerator Laboratory. "But one of the things that's been holding them back is their tendency to form dendrites, which are also the culprit behind overheating and occasional fires in today's lithium-ion batteries."

Dendrites form when a battery electrode degrades, and metal ions become deposited on the electrode's surface. When those finger-like deposits elongate until they penetrate the barrier between the two halves of the battery, they can cause electrical shorts, overheating and fires.

In a previous study published in October 2014, Cui and his colleagues reported that they had developed a 'smart' lithium-ion battery that senses when dendrites start to puncture the barrier so the battery can be replaced before the situation becomes dangerous. The research could offer a solution for millions of batteries now in use in cell phones, laptops and other devices, as well as in electric cars and airplanes.