WHAT DOES THERMAL RUNAWAY MEAN?

Thermal runaway or TP is the risk of “thermal runaway” of a battery.  If an internal short circuit occurs in the electrodes of a lithium-ion battery, for example due to contamination of the separator by a trapped foreign particle or mechanical damage, the short-circuit current can heat up the immediate vicinity of the damaged area due to the internal resistance. As a result, the surrounding areas are also affected. This process spreads and releases the energy stored in the accumulator within a short space of time. This escalation of the cell temperature can lead to an explosion and fire in the battery system. The main danger of thermal runaway is a probable chain reaction, thermal propagation.  The runaway of a battery cell is often due to the poor quality of the cell production. Thermal runaway leads to outgassing of the battery, which is represented by predetermined breaking cells, a so-called burst element. The outgassing of individual cells or cell packs is intended to prevent the occurrence of thermal propagation.