Study of 18650 LiFePO4 Lithium-Ion Battery Cells for Stationary and EV Applications: Performance, Reliability, and Safety

The increasing demand for energy storage in both stationary and electric vehicle (EV) applications necessitates a thorough evaluation of the performance, reliability, and safety of lithium-ion battery cells. Performance analysis involves investigating key parameters such as capacity, energy efficiency, and cycle life. Reliability assessment encompasses long-term cycling tests, accelerated aging experiments, and capacity retention analysis to determine the cells' durability under varying operating conditions. Safety evaluation involves analyzing thermal stability and determining the battery's state of health. This study presents a comprehensive assessment of 18650 LiFePO4 (LFP) lithium-ion battery cells for stationary and EV applications. The cells were aged at different temperatures, states of charge (SOC), and depths of discharge (DOD) to determine the extent of capacity fade and degradation. The results showed that the DOD and charging protocol during aging play a crucial role in the performance of the cells. Cells with lower DOD exhibited reduced capacity loss and higher state of health (SOH). Furthermore, the study indicates that cells stored in a fully discharged state at room temperature exhibit better capacity retention and higher SOH compared to cells stored at higher temperatures. The heat generation rate of all tested cells was relatively low, indicating the good thermal stability of the cells, ensuring their safety and performance.