Lithium-ion battery heat generation investigation based on calorimetric entropy measurements

Battery global heat generation is related to both joule heating and entropy change. Basically, joule heat is due to internal resistance reaction to current flow. However, electrochemical reactions that occur during charge and discharge affect battery entropy and thus affect heat generation. In this paper, we focus on the thermal behavior of 12 Ah high-power lithium-ion cell during charge-discharge at different C rates. We conduct a series of tests on an accelerated rate calorimeter (ARC). The cell heat capacity (Cp) is identified and global heat generated by the battery is quantified. We measure cell entropy using both the potentiometric and the calorimetric methods. The part of reversible reaction in the cell thermal behavior during charge-discharge tests is identified. Experimental results are presented and discussed.