Advances in Early Warning of Thermal Runaway in Lithium‐Ion Battery Energy Storage Systems

Abstract Thermal runaway is a critical safety concern in lithium‐ion battery energy storage systems. This review comprehensively analyzes state‐of‐the‐art sensing technologies and strategies for early detection and warning of thermal runaway events. The primary inducing factors, evolution mechanism, and characteristic reactions at various stages are discussed. Detectable signals during thermal runaway, including temperature, gas emissions, pressure, strain, and acoustic signals, are examined, along with advancements in corresponding sensing technologies. The importance of sensor implantation, collaboration, and communication within battery cells is highlighted, as well as the development of intelligent algorithms and early warning models. Miniaturized, integrated, and arrayed sensors within battery cells are identified as an inevitable trend in advancing safety monitoring systems. Intrinsically safe design of future battery systems, considering distinct thermal runaway characteristics of emerging technologies, is crucial for enhancing safety and reliability. Future research shall focus on developing advanced sensing technologies for real‐time, in situ monitoring, establishing a new paradigm for thermal runaway diagnosis using intelligent algorithms, and integrating battery models with these algorithms for accurate state estimation and early warnings. This review provides insights to guide the development of advanced sensing and early warning strategies, facilitating the widespread adoption of renewable energy storage technologies.