Model and experiments to investigate thermal runaway characterization of lithium-ion batteries induced by external heating method

Intentionally inducing worst-case thermal runaway scenarios in Lithium-ion batteries on-demand is a definitive way to test the efficacy of battery systems in safely mitigating the consequences of catastrophic failure. This study investigates the combined impact of heating power and heating area on thermal runaway triggering. Two different heating powers and four incremental heating areas constitute eight heating schemes in the experimental test. A 3D model is built in Comsol to satisfy the experimental result and investigate the heat transfer thermal runaway mechanism induced by external heating. The results indicate that when the heating power is the same, the smaller heating area that has higher heating power density can trigger TR quicker. The heater produces less heating energy, and less flux energy will be introduced into the battery. Thermal runaway prediction and recommended heating scheme map is proposed based on simulation result. The heating scheme with both high heating power and the small heating area has the greatest ability on shortening the heating time. The flux energy and its equivalent flux power pass through the interface between heater and battery is used to construct a comprehensive description of thermal runaway mechanism induced by heating method.