Experimental study on thermal runaway venting behaviour of LiNi0.8Co0.1Mn0.1O2 pouch cell under different sealing edge directions

In pouch cell modules, the sealing edges of the aluminum-plastic film are often installed facing either downward or up upward. The different sealing edge directions could lead to varying results of thermal runaway. The thermal runaway difference of different sealing edge install directions needs to be studied to help improve module safety. This paper proposes a novel experimental method for conducting thermal runaway tests on pouch cells with different sealing edge directions. The differences in heat generation and gas production of the cells are evaluated through Constant Volume Reactor and Gas Chromatograph analysis. The results indicate that the hazard is higher when the sealing edge is facing down compared to facing up. When thermal runaway is triggered in a 60 mm*60 mm heating area, the sealing edge facing downward delays the internal thermal runaway propagation time by 22.59 % compared to when it faces upward. The mass loss, peak venting pressure, and gas volume are respectively higher by 7.26 %, 14.52 %, and 1.78 %. Gas chromatograph analysis indicated minimal impact of sealing edge orientation on gas composition. This work provides guidance for the design of pouch cell modules, clarifying the optimal installation direction of sealing edges.