Integrated Design for Regulating the Interface of a Solid-State Lithium–Oxygen Battery with an Improved Electrochemical Performance

A composite solid-state electrolyte (SSE) with acceptable safety and durability is considered as a potential candidate for high-performance lithium–oxygen (Li–O2) batteries. Herein, to address the safety issues and improve the electrochemical performance of Li–O2 batteries, a solvent-free composite SSE is prepared based on the thermal initiation of poly(ethylene glycol) diacrylate radical polymerization, and an integrated battery is achieved by injecting an electrolyte precursor between electrodes during the assembly process through a simple heat treatment. The Li-metal symmetric cells based on this composite SSE achieve a critical current density of 0.8 mA cm–2 and a stable cycle life of over 900 h at a current density of 0.2 mA cm–2. This composite SSE effectively inhibits the erosion of O2 on the Li metal anode, optimizes the interface between the electrolyte and cathode, and provides abundant reaction sites for the electrochemical reactions during cycling. The integrated solid-state Li–O2 battery prepared in this work achieves stable long cycling (118 cycles) at a current density of 500 mA g–1 at room temperature, showing the promising future application prospects.