A Study on the Optimized Discharge Methods and Safety Verification of LFP Batteries

This study investigated the transportation safety of Lithium Iron Phosphate (LFP) cells by comparing and validating various discharge methods and safety tests. Experiments were conducted at 30%, 60%, and 100% SOC using external short-circuit, shunt resistor discharge, mechanical bending, and electronic discharge, and fire propagation risks were assessed through thermal propagation tests. The results showed that external short-circuiting caused ignition and rapid temperature rise, while shunt resistor discharge provided stable heat suppression and reproducibility but was limited by voltage rebound and long processing time. Mechanical bending was also insufficient for complete deactivation and therefore inappropriate as a standalone method. In contrast, electronic discharge to 0 V followed by external short-circuit prevented ignition and minimized temperature rise, demonstrating the most stable pretreatment approach. Accordingly, LFP cells can be transported with only lead-cutting when fire protection systems are available, whereas 0 V discharge followed by external short-circuit is essential under unprotected conditions. This study proposes an optimal pretreatment strategy to ensure the safe transportation of LFP batteries and highlights the need for further research on large-scale application and long-term stability.