Thermal mass refers to the ability of an object or system to absorb, store, and release thermal energy. It reflects the thermal inertia of the material in the process of temperature change, that is, the ‘slowness’ of heating up or cooling down.
In the battery system, thermal mass determines the response speed of the battery to temperature changes, directly affecting battery safety, thermal management system design, and risk control of thermal runaway.
The main functions include:
Buffering temperature changes: Materials with high thermal mass can slowly increase in temperature when the battery is subjected to thermal shock, which helps to delay the occurrence of thermal runaway;
Improving system thermal stability: It can reduce the temperature difference inside the battery, improve the uniformity of temperature distribution;
Influencing cooling/heating strategies: Systems with high thermal mass are more difficult to heat up or cool down, requiring the thermal management system to output greater power or preheat in advance;
Determining the rate of heat diffusion: It, together with thermal conductivity, affects the heat diffusion behavior between modules/packages.
