NVPF Sodium-Ion Versus NMC and LFP Lithium-Ion Batteries in Thermal Runaway: Vent Gas Composition and Thermal Analysis

In this study, cells with three different cell chemistries Na3V2(PO4)2F3 (NVPF), LiNi0.6Mn0.2Co0.2O2 (NMC) and LiFePO4 (LFP) are analyzed in exactly the same setup to compare the hazardous vent gases and their thermal behavior during thermal runaway (TR). Additionally, the influence of different triggers on the failure behavior of NVPF cells is elucidated. The innovative perspective is providing a direct comparison of the three cell chemistries, the influence of the trigger method on the vent gas composition and the thermal behavior. Of the three cell chemistries, LFP releases the least amount of vent gas at 0.02 mol/Ah (41% H2, 27% CO2, 8% CO), followed by NVPF at 0.05 mol/Ah (42% CO2, 17% electrolyte solvent, 15% H2 and 10% CO) and NMC at 0.07 mol/Ah (36% CO, 24% CO2, 19% H2). The maximum vent gas temperature increases from NVPF (265 °C) to LFP (446 °C) and NMC (1050 °C). As for the triggers, overcharge has the highest vent gas production of the NVPF cells at 0.07 mol/Ah. The results offer valuable insight into storage system design and expand the assessment of battery cells.