Energy Storage Science and Technology ›› 2025, Vol. 14 ›› Issue (7): 2820-2832.doi: 10.19799/j.cnki.2095-4239.2025.0016

• Special Issue on the 13th Energy Storage International Conference and Exhibition • Previous Articles     Next Articles

Thermal runaway gas detection and early warning of lithium-ion batteries

Zijing ZHANG(), Beibei YUAN(), Hong LI, Ying GAO   

  1. Anhui Gotion New Energy Vehicle Technology Co. , Ltd. , Hefei 230011, Anhui, China
  • Received:2025-01-06 Revised:2025-02-14 Online:2025-07-28 Published:2025-07-11
  • Contact: Beibei YUAN E-mail:zhangzijing@gotion.com.cn;yuanbeibei@gotion.com.cn

Abstract:

Thermal runaway of lithium-ion batteries (LIBs) is a significant safety concern because of the release of highly toxic and flammable gases. These hazardous emissions can increase the risk of asphyxiation and cause serious fire accidents. Therefore, using gas detection for early warning of thermal runaway is crucial for the safety design of battery cells and packs. In this study, a laser Raman spectroscopy analyzer was used to detect the composition and concentration of thermal runaway gases emitted by LIBs with different cathode materials at various states of charge (SOC). The results demonstrate that the gas signal of a lithium iron phosphate battery (LFP) is primarily concentrated between the opening of the battery valve and thermal runaway under different SOC conditions. In contrast, nickel cobalt manganese batteries (NCM) mainly showed gas signals after thermal runaway. These findings indicate that H2, CO, CO2, CH4, and C2H4 are theoretically feasible as characteristic gases for providing early warning of thermal runaway in batteries. Based on the experimental results for the battery cells, the above characteristic gases were further used for thermal runaway gas detection and early warning verification in the battery packs. A composite gas sensor that can measure CO2 and CO/H2/HC concentrations in real-time was used to detect characteristic gas changes at different locations inside battery packs. The gas concentration information was collected and uploaded to the battery management system (BMS). Compared with traditional cell temperature and voltage monitoring, gas signals provide a practical and effective method for the early warning of thermal runaway in battery packs. The results demonstrate that: ① the gas signal is negatively correlated with the distance between the sensor and the thermal runaway trigger battery. ② The CO/H2/HC signals are faster than CO2. Remarkably, even at the farthest detection location, CO2 gas can send an alarm signal at least 578 s before thermal runaway, demonstrating the effectiveness of gas-based early warning. ③ Compared with the temperature and voltage of traditional BMSs, gas signals offer a considerable competitive advantage for thermal runaway warnings. This study investigates gas generation during the thermal runaway process in LFP and NCM battery cells to verify the gas-based early warning system in their corresponding battery packs. The results demonstrate that gas-sensing technology can provide timely warning of thermal runaway in both LFP and NCM battery packs, providing a crucial reference for the development of LIB thermal-runaway early warning technology.

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

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