Lithium Metal/Organic Solid Electrolyte Interfaces to Stabilize Li Plating/Stripping Reaction

Solid-state Li metal batteries are attracting great attention as energy storage devices with high energy density and safety. However, the practical use is hindered by the low Coulombic efficiency of Li plating/stripping reactions due to interfacial issues between Li metal and solid electrolyte, such as reductive decomposition of electrolytes, whisker-like Li growth, and poor interfacial contact between the solid materials. Among solid electrolytes, flexible organic solid electrolytes are suitable for good Li metal/electrolyte interface formation. Particularly, salt-concentrated gel electrolytes have the potential to solve these issues because they will form superior solid electrolyte interphase (SEI) to suppress electrolyte decomposition and Li whisker growth. Here, we take the Li metal/salt-concentrated gel electrolyte interface as a model interface and discuss Li plating/stripping reactions, Li deposition morphology, and ion dynamics at the interface along with the coordination environments of the electrolytes.