Internal failure coupled with interfacial disintegration of solid-state electrolyte induced by the electrodeposition of lithium metal under defected interface

Owing to the introduction of the electrodeposition of lithium (Li) metal, the electro-chemo-mechanical (ECM) failure of solid-state electrolytes is accepted widely as the major challenge for the application of solid-state batteries with the expected higher energy density as well as the safety. It is no-doubtable the depth understanding of this failure process is of high importance. Herein, an ECM model based on the basic continuum damage mechanics that coupled with electrochemical kinetics was built to reveal the degradation process of solid-state electrolyte during the electrodeposition of Li metal. Not only the propagation of damage happens from the defected interface to bulk of solid-state electrolyte, the interfacial disintegration of solid-state electrolyte is pictured as well, illustrating the sources of the short circuit inside and the interfacial failure eventually. Moreover, the spontaneous occurrence of this electro-chemo-mechanical process inside the solid-state electrolyte in isolation, and that is regulated and exacerbated by the existence of internal voids significantly. Therefore, both of the interface and bulk of solid-state electrolyte are proposed to be strengthened, which can be paved as the promising pathways to prevent the failure of solid-state electrolyte for expanding the lifespan of solid-state Li metal batteries with higher energy density and satisfied safety.