Safety Studies on Sodium Batteries: Heat Generation and Thermal Abuse test

The interest in post-lithium batteries as an alternative to lithium-ion batteries boosted recently due to their substantial abundance, low-cost, inherent safety, and sustainability. In recent decades, the crucial need for the improvement of battery safety is emphasized and safety remains focused as a critical barrier for post-lithium technology. In a thermal management system, total heat generation during cycling procedures and exothermic reactions onset are one of the most important features to control the temperature of each cell/battery pack to mitigate the risk of thermal runaway (TR). Despite safer battery materials, battery thermal management would be a key to safer post-lithium technology.
Na0.53MnO2 and Na3V2(PO4)3/C based materials as cathode and coconut shell-derived hard carbon (HC) as anode together with 1M NaClO4 in EC:DMC: EMC (vol, 1:1:1) plus 2% FEC in volume as electrolyte were studied. The heat generated during charging and discharging had been determined using an advanced MS80 3D Tian-Calvet calorimeter (Setaram Instrumentation, France) under isothermal conditions at 25 °C in the respective full cells. It was observed that during the charging process less heat was generated than during the discharging process. ... mehrFurthermore, it was observed that cell balancing shows a pronounced effect (approximately 40% in charging and 20 % in discharge) on the amount of heat generation which is a significant feedback for the cell designers. Finally, the exothermal reactions were identified by a Heat-Wait-Seek test in an accelerating rate calorimeter (ES-ARC, THT, UK). Thermal data and exothermal reactions give a relationship between different critical thermal and safety-related issues in beyond lithium batteries. These analyses are very essential for the state of health, aging prediction as well as subsequent tackling of safety-related issues in the post-lithium system.