Recent advances in semiconductor gas sensors for thermal runaway early-warning monitoring of lithium-ion batteries

Abstract

With the widespread application of lithium-ion batteries in electric vehicles and renewable energy storage, safety issues have become increasingly important. Lithium-ion batteries may experience thermal runaway under conditions such as overcharging and thermal abuse, leading to serious safety incidents. Therefore, timely monitoring and early warning of thermal runaway in lithium-ion batteries are crucial for ensuring their safe operation. Current monitoring methods mainly include temperature sensors, voltage monitoring, and gas sensors. Although temperature sensors and voltage monitoring are relatively mature, they lack sufficient sensitivity for early detection of thermal runaway. In contrast, gas sensors, particularly semiconductor gas sensors, have gradually become a research hotspot due to their high sensitivity and rapid response. The performance of semiconductor gas sensors primarily depends on their material composition and sensing mechanisms, which are usually based on the interactions between gas molecules and the surface electrons of the semiconductor. This paper discusses the sensitivity enhancement mechanisms of materials in detail from five perspectives: microstructure, micro-morphology, noble metal modification, element doping, and heterostructures. Based on recent reports, insights into the performance improvement and application potential of gas-sensitive materials are provided, offering new ideas and directions for future research. Additionally, this section elaborates on the working principle of lithium-ion batteries and the reaction mechanisms of thermal runaway. When thermal runaway occurs in lithium-ion batteries, the internal reactions can be divided into several stages based on temperature: dendrite formation, decomposition of the SEI film, reactions between the anode material and the electrolyte, melting of the separator and short-circuiting, decomposition of the electrolyte, and reactions between the electrolyte and the cathode and binder. These processes are accompanied by the generation and consumption of characteristic gases such as H₂, CO₂, CO, CH₄, and HF. Focusing on the characteristic gases of thermal runaway, the latest developments in semiconductor gas sensors in recent years are discussed in detail. A thorough review and in-depth summary of articles related to the use of semiconductor gas sensors for safety detection of thermal runaway in lithium batteries over the past few years are provided, aiming to help readers quickly and comprehensively understand and grasp the key technologies and current developments in this field. Finally, the future development directions of semiconductor sensors in thermal runaway of lithium-ion batteries are envisioned, including further innovations in materials, enhanced multi-component gas detection capabilities, innovative detection mechanisms, and integration with intelligent algorithms and data analysis technologies. These approaches are expected to achieve more precise early warning monitoring of thermal runaway, improving the safety and reliability of lithium-ion batteries. In summary, the application prospects of semiconductor gas sensors in monitoring thermal runaway in lithium-ion batteries are broad and worthy of in-depth exploration and research.