Experimental Investigation of Voltage Limitation Modes and State of Power Estimation for a High-Power Lithium-Ion Battery

Abstract

This paper investigates the behaviour of a high-power lithium-ion battery (LIB) pouch cell under voltage limitation at a high state of charge (SOC). The state of power (SOP) estimation is crucial in providing insights into optimising energy recovery during regenerative braking events. Experiments were conducted at different high-charging C-rates to analyse the voltage limitation modes and to assess the accuracy of a model-based SOP estimation algorithm developed based on published literature. The results show that the accuracy of the battery model alone is not sufficient to address the accuracy of the SOP estimation algorithm. Furthermore, different voltage limitation modes are discussed and the average power output is investigated. For example, it was observed that Constant-Current Constant-Voltage (CCCV) mode outputs 59.75% more power than Constant-Current (CC) pulses. These findings provide valuable insights into the behaviour of high-power LIB pouch cells and offer a foundation for further research to improve regenerative braking performance for motorsport applications.