Thermal runaway hazards comparison between sodium-ion and lithium-ion batteries using accelerating rate calorimetry

Sodium-ion batteries (SIBs) are gaining popularity due to their wide source of raw materials and low manufacturing cost. However, the thermal runaway (TR) characteristics and hazards of SIBs are currently unknown. In this study, the TR characteristics and hazards of three types of 18650 batteries, SIB with NaxTMO2 (NTM) as the cathode and two types of lithium-ion batteries (LIBs) with LiFePO4 (LFP) and LiNi0.5Co0.2Mn0.3O2 (NCM) as the cathode, are investigated and comparatively analyzed by using a standard accelerated calorimeter (ARC). The TR maximum temperature and the maximum temperature rise rate of the NTM battery are 511.7 °C and 2285.5 °C/min, respectively, which are intermediate between the LFP and NCM batteries. The calculation results show that the frequency factor (lnA) and activation energy (Ea) of the NTM batteries are 13.312 lg /s and 0.8840 × 105 J /mol, respectively. Under natural convection conditions, a fully charged NTM battery can spontaneously ignite if the storage temperature exceeds 169.6 °C. Finally, the TR hazard of SIB and LIBs are qualitatively evaluated by the TR assessment model, the TR hazard of NTM is between LFP and NCM batteries, with a preference for LFP battery. This work is instructive for the hazard assessment of SIB and promotes the development of research on the SIB safety.