Electro-Chemo-Mechanical Failure Mechanisms of Solid-State Electrolytes

Review article, 2023

Solid-state lithium-metal batteries (SSLMBs) are considered as the next-generation energy storage systems due to their high theoretical energy density and safety. However, the practical deployment of SSLMBs has been impeded by the failure of solid-state electrolytes (SSEs) which is indicated by the increased impedance, elevated polarization, and capacity degradation. The failure is commonly a result of lithium (Li) dendrite growth and propagation, inactive Li generation, unstable interface formation, void and pore formation, and crack infiltration. The failure processes can be divided into electric failure, (electro)chemical failure, and mechanical failure based on the different mechanisms. The systematical understanding of SSEs failure is crucial for the development of SSEs. Therefore, this review comprehensively summarizes the details of the three SSEs failure to provide new insights for future studies, shedding light on the design of SSLMBs with high energy density, safety, and cycling stability. Failure mechanisms: This review provides a comprehensive summary of the coupled electro-chemo-mechanical failure mechanisms of solid-state electrolytes. The electric failure results from the short circuits caused by growth and propagation of Li dendrites and the capacity loss because of inactive Li formation. The formation of kinetics/thermal unstable interphase accounts for the (electro)chemical failure. Cracks infiltration and voids/pores formation lead to mechanical failure.