Effects of Different Safety Vent Bursting Pressures on Lithium-Ion Battery Thermal Runaway Process and Reaction Product Compositions

Abstract

With the accelerated application of lithium-ion batteries, the design and optimization of their safety features have become increasingly important. However, the mechanisms by which different safety vent bursting pressures affect thermal runaway and its product compositions remain unclear. This study comparatively investigates the effects of safety vent bursting pressures of 1 MPa, 2 MPa, and 3 MPa on thermal runaway characteristics and product compositions. The results indicate that, under these three conditions, the safety vent bursts at approximately 800 s, 1000 s, and 1300 s after heating begins, with gas volumes of 5.3 L, 6.1 L, and 6.5 L, respectively. Additionally, higher bursting pressures lead to increased H2 production during thermal runaway. The characterization of solid product compositions reveals that the aluminum current collector participates in internal thermal runaway reactions, resulting in substances such as LiAlO2 or metallic Al in the solid products under different bursting pressures. This study provides important references for improving existing battery safety standards and optimizing battery safety designs. It also provides insights and references for metal recovery from batteries and investigations into battery fires.

Keywords

• lithium-ion batteries
• thermal runaway
• safety vent bursting pressure
• reaction product composition