The Degradation Behavior of LiFePO4/C Batteries during Long-Term Calendar Aging

With widespread applications for lithium-ion batteries in energy storage systems, the performance degradation of battery attracts more and attention. Understanding battery’s long-term aging characteristics is essential extension service lifetime safe operation system. In this paper, lithium iron phosphate (LiFePO4) were subjected to (i.e., 27–43 months) calendar under consideration three stress factors time, temperature state-of-charge (SOC) level) impact. By means capacity measurements resistance calculation, behaviors tracked over time. Battery models established by a simple but accurate two-step nonlinear regression approach. Based on model, effect SOC level fade internal increase analyzed. Furthermore, life with respect different predicted. The analysis results can hopefully provide suggestions optimizing condition, thereby prolonging batteries.