Thermal Runaway of Na-Ion Batteries with Na3V2O2(PO4)2F Cathodes

Abstract

The metal-ion battery manufacturing growth rates increase attention to the safety issues. For promising sodium-ion batteries, this topic has been studied in much less detail than for the lithium-ion ones. Here, we explored the thermal runaway process of Na-ion pouch cells with the Na₃V₂O₂(PO₄)₂F (NVOPF)-based cathode. The thermal runaway onset temperature for such cells is noticeably higher than that for the NMC-based LIBs. We show that thermal runaway is triggered by the anode and the separator decomposition rather than by the processes at the cathode. The composition of the gas mixture released during thermal runaway process is similar to that for Li-ion batteries. The results suggest that sodium-ion batteries based on polyanionic cathodes can pave the way to safer metal-ion energy storage technologies.