Electro-Thermal Coupling Modeling and Heat Generation Decoupling Analysis of Semi-Solid-State Lithium-Ion Battery

Abstract

Solid-state batteries are increasingly seen as the future of battery development due to their higher energy density and improved thermal stability. While all-solid-state batteries are gaining attention, semi-solid-state batteries, serving as a bridge between liquid batteries and all-solid-state ones, have not been extensively studied. This article delves into the electro-thermal characteristics of a commercial semi-solid-state battery through various experiments like HPPC, adiabatic calorimetry, and entropy heat coefficient analysis. It compares the internal resistance traits with those of a similar liquid lithium-ion pouch battery. By integrating a second-order RC equivalent circuit model with the Bernardi heat generation model, a comprehensive electro-thermal coupled model for semi-solid-state lithium-ion batteries is established. This model considers parameters such as temperature, state of charge, and charge/discharge rates to accurately predict terminal voltage, reversible and irreversible heat generation power, and temperature variations. The study demonstrates a high prediction accuracy with the maximum root mean square error of 0.043 V for terminal voltage, 0.67 W for heat generation power, and 0.56°C for temperature. Following the validation of the model, an analysis is conducted to dissect the different components contributing to battery heat generation. The insights gained from the characteristics analysis and electro-thermal model of semi-solid-state batteries can be valuable for enhancing the control strategies of battery management systems in the future.