Hysteresis

In the field of batteries, hysteresis usually refers to the phenomenon where the voltage-capacity (V-Q) curve during charging and discharging does not coincide. Even when the battery is at the same state of charge (SOC), the voltages during charging and discharging are different, and this path dependence exhibits a ‘hysteresis’ characteristic.
Performance in batteries: During the charging process, the voltage of the battery is usually higher than the discharge voltage at the same SOC. On the voltage-capacity graph, it forms a **’figure-eight’**, which is a hysteresis loop. The size of the hysteresis varies with factors such as temperature, aging degree, and current rate.