LAUSR

In this article, a novel composite battery model is developed, and a parameter and state-of-charge (SOC) joint estimation model is designed. The developed composite battery model considers the important reactions such as the solid–liquid phase diffusion of Li+. The relationship between the electrochemical reactions inside the battery is obtained, and the corresponding structure is designed for characterization. Based on the composite battery model, a parameter and SOC joint estimation model is established to adapt to various environments and obtain an accurate SOC estimation result. As experiments of different types of battery provided by China First Automobile Work confirmed, the developed composite battery model can increase the model accuracy of the equivalent circuit model without significantly increasing the model complexity. The designed parameter and SOC joint estimation model can obtain a favorable SOC estimation result under various environments.