How do lithium ion batteries self-extinguish?

Li-ion batteries are extremely flammable, but are able to stop themselves from catching on fire. 

14th May 2017
Why do li-ion batteries self-extinguish? (Getty)

Lithium ion batteries contain a highly flammable electrolyte solution that allows ions to move from anode to cathode and back through a separator. However, if there is an internal short circuit, heat can build up, and the battery can potentially burst into flame.

Diagram of Li-ion battery
© Raja Lockey

Stanford researchers have developed a new separator made of polymer that contains triphenyl phosphate (TPP), which is flame retardant. If temperatures reach 150°C, the polymer shell melts, releasing the TPP to prevent combustion.


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