Thermal behaviors of lithium-ion cells during overcharge

The heat generation behavior in the overcharge has been investigated experimentally for various lithium-ion cells. Generated heat flow was examined by calorimetric measurement for different charging rates as a parameter and discussed. It is clarified that the heat generation during the overcharge is almost proportional to charging current. It is considered that if the cooling system can remove the equivalent heat to electrical input, it is possible to prevent the thermal-runaway which originates from the overcharge.