Preferential Lithium Plating in the Interfacial Void Region in All-Solid-State Batteries via Pressure Gradient-Driven Lithium-Ion Flux

Abstract

All-solid-state batteries (ASSBs) are considered to be a breakthrough that overcomes the limitations of conventional lithium-ion batteries. However, the morphological instability caused by dendritic Li growth leading to short-circuiting is a critical problem, and solving it is still an outstanding conundrum. In this work, we demonstrate that the morphological instability can be bypassed by developing a pressure gradient between the land (contact) and void (noncontact) regions of the interface of the solid electrolyte and electrode. This pressure gradient leads to inward Li plating of the interfacial void space in a structured electrode. Using simulations and investigations of Li plating morphology for a square hole-patterned electrode and a sulfide electrolyte, we demonstrate that the pressure gradient at the interface directs total Li+ flux toward the void region, resulting in preferential Li plating in the interfacial void space. This work provides a new academic strategy for controlling the direction and position of Li plating in ASSBs.