TheConversation.com

Another factor that makes lithium-ion battery fires challenging to handle is oxygen generation. When the metal oxides in a battery’s cathode, or positively charged electrode, are heated, they decompose and release oxygen gas. Fires need oxygen to burn, so a battery that can create oxygen can sustain a fire.

Because of the electrolyte’s nature, a 20% increase in a lithium-ion battery’s temperature causes some unwanted chemical reactions to occur much faster, which releases excessive heat. This excess heat increases the battery temperature, which in turn speeds up the reactions. The increased battery temperature increases the reaction rate, creating a process called thermal runaway. When this happens, the temperature in a battery can rise from 212 F (100 C) to 1,800 F (1000 C) in a second.