Abstract: Due to the characteristic gas generation during the thermal runaway process of lithium-ion battery, it could be early warned by detecting the gas emission and concentrations. In this paper, the generation mechanism of thermal runaway gas was introduced. The research status on influence of battery type, battery parameters and external environment on the thermal runaway gas were summarized, as well as the producing phenomenon of different characteristic gas. The recent progress on the early warning of the thermal runaway of lithium ion battery based on the detection of gas was reviewed and analyzed. Moreover, the future development in this field was also prospected, which could provide some directions for improving the operation security of li-ion battery.

Key words: lithium-ion battery, thermal runaway, characteristic gas, early warning