A novel pulse resistance based thermal runaway early detection approach for lithium-ion and sodium-ion batteries

Abstract

Temperature monitoring of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) is essential for safe operation, as excessive temperature can trigger a thermal runaway (TR) event. Although surface temperature sensors have traditionally been used, their limitations have led to the exploration of alternative methods. Notably, estimating temperature based on pulse resistance ($R_{\mathrm{DC}}$) has emerged as a promising approach. Nonetheless, this method has not yet been investigated at temperatures exceeding the cell’s safety limits, highlighting a research gap for its application in TR early detection. In this study, the $R_{\mathrm{DC}}$-temperature relationship was characterized at temperatures exceeding the cell’s safety limits for two different LIB technologies and a SIB. The results revealed a turning point in the $R_{\mathrm{DC}}$-temperature relationship between 60 °C and 70 °C for both LIB technologies and at approximately 110 °C for the SIB. From this turning point, $R_{\mathrm{DC}}$ increases with increasing temperature. This contradicts the loss of sensitivity of $R_{\mathrm{DC}}$ to temperature variations predicted by the Arrhenius model at temperatures typically encountered during a TR event. Finally, a novel TR early detection approach based on the characterized $R_{\mathrm{DC}}$ behavior during a TR event is proposed. The strength of the method lies in the combination of two monitored $R_{\mathrm{DC}}$ properties changing during TR.