Dependence of OCV, Hysteresis, Overvoltage on Temperature and SOC in Commercial LiFePO ₄ Lithium‐Ion Battery

ABSTRACT We present the experimental results of the dependences of the open‐circuit voltage (OCV), its hysteresis and the overvoltage in commercial LiFePO 4 lithium‐ion‐batteries (LFP‐LIB). Our results show that the OCV has minor dependence on temperature but depends on state‐of‐charge (SOC), while the hysteresis and overvoltage depend on both temperature and SOC. The dependence of hysteresis on SOC is nonlinear, and it has a bimodal characteristic at low temperature while unimodal at high temperature. These results suggest that if we employ modelling which takes into account the effects of temperature and SOC on hysteresis voltage, we can construct control systems of the LIB with higher accuracy than is currently possible.