Thermal Runaway Mechanisms and Prevention Strategies in Lithium-Ion Batteries for Energy Storage

This chapter presents a systematic review of research advancements in the thermal safety of lithium-ion batteries for energy storage, with a focus on the mechanisms, early warning, and prevention and control strategies of thermal runaway. It begins by elucidating the fundamental structure, working principles, and heat generation mechanisms of lithium-ion batteries during charge and discharge, establishing an electrochemical–thermal coupling theoretical foundation for understanding thermal runaway. The review then provides an in-depth analysis of the root causes triggering thermal runaway, including separator rupture and internal short circuits due to mechanical abuse, cascading side reactions induced by electrical abuse (overcharge/overdischarge), and material decomposition and reaction runaway activated by thermal abuse. Key characteristic precursor signals of thermal runaway, such as temperature anomalies, voltage/current irregularities, and gas generation features, are analyzed in detail, offering a physicochemical basis for early warning. Furthermore, the chapter reviews thermal runaway prediction technologies, spanning from physics-based models grounded in reaction mechanisms to early warning methods based on gas composition analysis and data-driven intelligent diagnosis models utilizing machine learning. Regarding safety mitigation, recent achievements in enhancing the intrinsic safety of batteries through strategies like electrode material design and the application of high-stability separators are summarized. Finally, future challenges and directions are prospected, including balancing high energy density with safety, understanding the evolution of thermal runaway risk throughout the entire battery lifecycle, and exploring integration pathways for new materials and intelligent sensing technologies.