Lithium-ion battery sudden death: Safety degradation and failure mechanism

Environmental pollution and energy scarcity have acted as catalysts for the energy revolution, particularly driving the rapid progression of vehicle electrification. Lithium-ion batteries play a fundamental role as the pivotal components in electric vehicles. Nevertheless, battery sudden death poses substantial challenges to battery design and management. This work comprehensively investigates the failure mechanism of cell sudden death under different degradation paths and its impact on cell performances. Multi-angle characterization analysis shows that lithium plating is the primary failure mechanism of battery sudden death under different degradation paths. However, the formation mechanisms of lithium plating differ in various degradation paths. In the path-L and path-F, the limited lithium intercalation rate in graphite leads to lithium plating, while localized anode drying and uneven potential distribution are the causes in the path-H and path-R. Furthermore, sudden death significantly reduces the cell electrochemical performances and thermal safety, but the cell performance evolution varies under different degradation paths. Sudden death primarily affects the anode interface polarization process in the path-L and path-F, with a more severe impact on cell thermal safety. However, sudden death mainly affects the charge transfer process, with a relatively milder impact on cell thermal safety. These findings can provide valuable insights for optimizing battery design and management.