Estimation methods for States of Charge and Health of Lithium-ion battery

Abstract

A battery energy storage system is one of the practical and effective ways to achieve carbon neutrality. Lithium-ion batteries are widely used because of their long cycle life, high energy density, high rated voltage, and low self-discharge rate, etc. Their large-scale application has put forward higher requirements for the battery management system (BMS) to ensure the reliable operation of batteries. However, due to the electrochemical reactions and complex operating conditions inside the battery, it is difficult to accurately assess the internal state of the battery. The state of charge (SOC) and state of health (SOH) are two important parameters in the battery management system. This paper systematically summarizes the current commonly used SOC and SOH estimation methods and analyzes the characteristics of each method. The problems and future research trends of battery SOC and SOH estimation techniques are also described, which are expected to provide a reference for further research in this field.