PE-based film prevents lithium-ion batteries from overheating

The thin polyethylene film is embedded with spiky nanoparticles of graphene-coated nickel. (Source: Zheng Chen, Standford University)

Bunched together, as shown here, nanoparticles of graphene-coated nickel conduct electricity. When the battery overheats, the particles separate and electric current stops flowing. During cooling, the particles reunite and the battery starts producing electricity again. (Source: Zheng Chen)