All-Solid-State Potassium Polymer Batteries Enabled by the Effective Pretreatment of Potassium Metal

Abstract

K metal disk electrodes, prepared by putting a chunk of K metal in a 1,2-dimethoxyethane (DME) solution containing potassium bis(fluorosulfonyl)amide (KFSA) and 1,3,2-dioxathiolane 2,2-dioxide (DTD), exhibited suppressed polarization and interfacial resistance in continuous metal stripping–deposition reactions of a symmetric half-cell comprising a cross-linked polymer electrolyte. This simple and effective pretreatment process enhances passivation layer formation, enabling fabrication of the first 3 V-class all-solid-state K-ion battery operated at room temperature.