Conventional lithium-ion batteries are known to present a fire risk, and can even cause explosions in certain cases. The widespread usage of lithium-ion batteries, in everything from electric vehicles to electric toothbrushes, makes lithium-ion battery fire risk mitigation a major priority. There is a great need for lithium-ion battery designs that balance long cycle life, high voltage, and safety.

The fire risk arises when lithium-ion batteries undergo some kind of physical damage, are overcharged or even when they have manufacturing defects. This causes thermal runaway when anions—or negatively charged ions—break their bonds with lithium and release heat. Conventional lithium-ion batteries can undergo a temperature change of over 500°C when this occurs.

However, researchers in China have now found a way to drastically reduce the heat released when lithium-ion batteries are damaged. Their study, published in Nature Energy, details the new design and the experimental results of nail penetration tests, in which the temperature rise was only around 3.5°C.