Thermal runaway

One of the challenges of working with batteries is that they are undergoing a continuous chemical reaction process. From charging to releasing energy back to the system. The reaction should happen under controlled conditions (temperature, current, etc.) There is a chance that a battery can "short-circuit" internally, leading to an increase in temperature, which leads to more current, etc.

Sometimes (but not always), this happens when the battery is damaged: that's why you should not move your seat at an airplane if you lose your phone.

However, deterioration of batteries can also lead to thermal runaways.

In any case, the situation will be the same: a chain reaction that can't be stopped, and temperatures reaching several hundreds of degrees, enough to start a fire.

There is a fair chance that measuring outgassing can prevent thermal runaway of batteries