Putting the brakes on lithium-ion batteries to prevent fires

Lithium-ion (Li-ion) batteries are used to power everything from smart watches to electric vehicles, thanks to the large amounts of energy they can store in small spaces. When overheated, however, they're prone to catching fire or even exploding. But recent research offers a possible solution with a new technology that can swiftly put the brakes on a Li-ion battery, shutting it down when it gets too hot.