Numerical study of thermal characteristics in a Li||Bi liquid metal battery subject to internal short circuit

Abstract

Liquid metal batteries (LMB) are emerging as a promising solution for grid-scale energy storage due to their high capacity and cost-effectiveness. Given the intricate nature of energy transfer during the internal short circuit (ISC) process in LMB, a multi-physics model is introduced in this paper to investigate the heat generation power and temperature distribution during ISC in 40 Ah Li||Bi LMB. The influence of the critical factors—state of charge (SOC), short location and short area size—on ISC is analyzed through a parametric sweep approach. Results reveal that the heat generation during ISC in LMB primarily stems from the alloying chemical reaction between the metallic electrodes (e.g., lithium and bismuth forming Li₃Bi). The heat generation rate is predominantly influenced by SOC and the short-circuit area size, as these factors govern the reaction kinetics. Additionally, the heat transfer pathway is largely determined by the short-circuit location. During the ISC process, the most severe temperature rise occurs with a peak heat generation rate of 675 W and a peak temperature of 888 °C after 168 s. Furthermore, a temperature rise rate of 1 ^oC/s for the anode is proposed as a reliable boundary for the early warning of ISC in LMB.