Simulation study on internal short circuit of lithium ion battery caused by lithium dendrite

The internal short circuit of the lithium ion battery (LIB) is one of the main reasons that cause thermal runaway. Mechanical, thermal, and electrical abuse of LIBs may lead to irreversible growth of lithium dendrites. Short circuits will happen inside the battery if the separator is pierced by the lithium dendrites growing to a certain extent. In this paper, the internal short circuit of LIBs caused by lithium dendrites is simulated by finite element numerical simulation method. The thermal response characteristics of LIBs under various time, radius, and center distance of lithium dendrites are compared and analyzed. The results show that the heat production of short circuit in LIB caused by lithium dendrite is mainly contributed by the positive and negative electrodes. The short-circuit current, heat production power and maximum temperature of the battery increase with the increase of the lithium dendrite radius. Meanwhile, when the center distance of lithium dendrites increases, the short-circuit current and heat production power also increase. The greater the center distance of lithium dendrite, the greater the total heat production of the battery. For example, when the center distance of lithium dendrite is 2700 µm, the total heat production reaches 0.2161 J, which is 1.9 times that of 0 µm (0.1129 J). We believe that the simulation results related to lithium dendrites obtained by the three-dimensional electrochemical-thermal coupling model can provide relevant theoretical basis for the experimental research on the growth of lithium dendrites, short circuit and heat production in LIBs, and help to design safer LIBs.