What role does the safety valve play in the safety of lithium-ion cells? Part II. Cells with various states of health and formats

• Published in: Journal of thermal analysis and calorimetry 2024-11, Vol.149 (21), p.11891-11901
• Main Authors: Ouyang, Dongxu, Pang, Yimei, Huang, Jian, Wang, Zhirong
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Electric cells; Hazard mitigation; Inorganic Chemistry; Lithium-ion batteries; Measurement Science and Instrumentation; Overheating; Physical Chemistry; Polymer Sciences; Safety valves; Thermal runaway
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-024-13540-7

To demonstrate the role of safety valves in enhancing the safety characteristics of lithium-ion cells, this study conducts a set of abusive testing including accelerating rate calorimetry testing, overheating testing, and overcharge testing. Additionally, the influence of safety valves on cells with different states of health (100%, 90%, and 80% SOH) and formats (14,650, 18,650, and 22,650) is investigated. The results reveal that safety valves have a substantial influence on the thermal runaway behaviour of cells. They effectively mitigate the risks and hazards associated with thermal runaway during overheating and ARC conditions. Beyond that, the presence of a safety valve can prevent thermal runaway triggered by overcharge. It is observed that cells with lower SOH and/or smaller diameters are more prone to experiencing earlier thermal runaway. Furthermore, this research finds that the influence of safety valves is more pronounced in cells with less degradation and/or smaller formats.