Polymer-Based Solid-State Batteries

Polymer-based solid-state batteries exhibit desired properties of good safety and high energy density, and they are very likely to become the devices of choice for the next generation of energy storage. Among solid electrolytes, polyoxyethylene (PEO)-based polymer electrolytes are widely used in solid-state batteries. However, the electrochemical window of electrolytes themselves is narrow, which limits further improvement of energy density. At present, only LiFePO4 is suitable for paring with a PEO electrolyte, and such a limitation severely hinders the real-world application of PEO polymer solid-state batteries. In particular, the side reactions at the interface between the electrode material and the PEO polymer electrolyte are the main challenge that greatly shortens battery cycle life. To suppress these side reactions, people have adopted corresponding strategies and achieved considerable progress. In order to fully understand the changes at the interface of solid-state batteries, various advanced characterization methods have been employed. This will provide a more scientific basis for improving the cycle stability of solid-state batteries in the next stage.