Characteristics of particle emissions from lithium-ion batteries during thermal runaway: A review

The thermal runaway (TR) of lithium-ion batteries (LIBs) is hindering the large-scale promotion of new energy vehicles. The process of TR is often accompanied by high-temperature air flow and the eruption of particles. The particle emission was supposed to pose a risk of igniting combustibles in the surrounding environment. Relevant studies have been conducted, but reviews of these studies are lacked. Therefore, we summarize the properties of particles released upon the TR of LIBs, including morphology, mass, size, thermal stability, chemical composition, spread and deposition, temperature, and eruption distance. It was found that most of the particles appear as black, irregular-shaped powders, and their main components are carbon, carbonates, metals, metal oxides and various organic matter. Particle contains >30 elements, of which up to 40 % are metals, and >70 % of metals are polluting to the atmosphere, soil or water. Owing to different particle sizes, particles may eventually be deposited or suspended in the air, harming the environment and human body. Therefore, it is necessary to strengthen the research, supervision and treatment of LIB particle emissions. Specifically, conduct an in-depth study of the temperature and eruption range of sparks, and focus on the analysis of non-metallic elements, and conduct a comprehensive composition analysis and determination, and study the influencing factors of particle size distribution and guide the design of protective masks. Our work may pave the way for providing theoretical guidance for improving the safety of LIBs and establishing effective particle emission management methods.