Investigation on electro-thermal behavior of liquid metal batteries under various abusive conditions

Liquid metal batteries (LMB) are one of the most promising solutions for grid-scale energy storage due to their characteristics of long life and low cost. On account of the all-liquid structure of LMB, the main challenge faced by many researchers is the impact of abusive conditions on the liquid-liquid interface stability and the intrinsic safety after an internal short circuit (ISC). This study set out to compare the influence of different abusive conditions on the electro-thermal characteristics of LMB through systemic experimental research, including mechanical (vibration, inclination), electrical (external short circuit) and thermal abuse (thermal shock). Results show that LMB has a strong self-healing ability under abuse conditions. It is worth mentioning that almost all the deformation of voltage and temperature caused by abusive conditions can be restored after the abuse is stopped, except for the ISC caused by the entire inclination. In comparison, mechanical abuse is more likely to induce ISC failure of LMB than electrical abuse and thermal abuse. In the vertical vibration of more than 10 Hz and inclination of more than 39.3°, the signs of transient ISC appear in the LMB voltage and temperature. Compared with mechanical abuse, there is only a temperature rise (550 °C to 564 °C) and coulombic efficiency reduction (98.3 % to 8 %) in the electrical and thermal abuse. This work is one of the first attempts to thoroughly examine the abuse performance of LMB and provides the first comprehensive assessment of LMB thermal safety.