Thermal response of lithium-ion battery during charging and discharging under adiabatic conditions

The thermal responses of the lithium-ion cells during charging and discharging are investigated using an accelerating rate calorimeter combined with a multi-channel battery cycler. The battery capacities are 800 and 1100 mAh, and the battery cathode is LiCoO2. It is found that the higher the current rates and the increased initial temperatures are, the greater the potential thermal hazard is. The temperature required to shut down the separator is 133 A degrees C for this separator used in the battery. When the temperature exceeds this activation threshold temperature, the separator will melt and cause an internal short circuit between the electrodes. The heat generation during the discharging process is measured under adiabatic conditions. The heat generation at thermal runaway process contributes to the main heat in the whole experimental process. The total heat generation rate to cell capacity varies from 6.58 to 8.96 J mAh(-1) in the six cases. The results can be used to investigate and provide guides for designing concepts for the safe use of lithium-ion batteries.