Battery performance and safety are pivotal to long-term electric vehicle (EV) success, but thermal runaway remains a persistent concern. It stems from the limitations on temperature: batteries are only really happy within a narrow temperature range. The stability of the cells hinges on maintaining that sweet spot.
When temperatures exceed that range a chemical reaction begins and if it goes unchecked the cell will continue to heat up until it vents, ejecting some of its electrolytes in a gaseous form. If that is not stopped the cell will initialise its own burning, starting an exothermic reaction that can trigger the cells around it. In some cases this results in the batteries melting or suffering irreparable damage, but in extreme situations batteries can explode and the vehicle can catch on fire.
