In a study that could improve the safety of next-generation batteries, researchers discovered that adding two chemicals to the electrolyte of a lithium metal battery prevents the formation of dendrites – “fingers” of lithium that pierce the barrier between the battery’s halves, causing it to short out, overheat and sometimes burst into flame.

The findings, published June 17 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...

... In tests, batteries with both chemicals added operated at 99 percent efficiency after more than 300 charge-discharge cycles, compared to significantly decreased efficiency after 150 cycles for batteries treated with lithium nitrate alone, said Fiona (Weiyang) Li, a postdoctoral researcher in Cui’s lab and first author of the paper.

“This is a really exciting observation,” she said. “We had been doing experiments all along with these two chemicals in there, but this was the first time we looked at the synergistic effect. This does not completely solve all the problems associated with lithium metal batteries, but it’s an important step.”