Thermal Runaway

Thermal runaway is a self-accelerating, uncontrolled temperature rise in a battery cell or pack, triggered by thermal (overheating or fire), electrical (overcharging or high currents), or mechanical (piercing, crushing) causes. Rising temperatures damage internal components—separator, electrolyte, anode, and cathode—leading to exothermic reactions. For lithium-ion batteries, once temperatures reach ~150–200 °C, heat generation accelerates uncontrollably, potentially increasing 5–10 °C per minute, ultimately causing catastrophic failure.