Effects of Local Thermal Accumulation Conditions on the Thermal Characteristics of Lithium-Ion Batteries under High-Rate Charging

Abstract

Electric vehicles use lithium-ion batteries as their power source; however, many researchers have expressed concern about the safety of these batteries. In this study, a new method was used to establish an accurate model of a lithium-ion battery, which can be used to calculate the heat production of lithium-ion batteries and the change in lithium-ion concentration. The effect of local heat accumulation on the thermal characteristics of lithium-ion batteries was studied. The electrochemical heat generation and side-reaction heat generation of lithium-ion batteries under rates of 1C, 3C, and 5C were compared (C-rate is the measurement of the charge and discharge current with respect to its nominal capacity). The results show that adding the heat source during charging can reduce electrochemical heat generation but increase side-reaction heat generation. At the same time, adding heat will accelerate the precipitation of a lithium-ion battery, improving the overall temperature of the battery.