Constructing poly(ethylene oxide)-based composite solid electrolytes: starting from the internal mechanism in batteries

Solid polymer electrolytes (SPEs) represented by poly(ethylene oxide) (PEO) stand out in the realms of environmental sustainability and processability. Their high flexibility, a characteristic of polymer materials, renders them irreplaceable in applications such as wearable devices and flexible electronic components, positioning them as promising candidates for large-scale commercialization in the future. Nonetheless, PEO-based SPEs exhibit limitations in their ionic conductivity, electrochemical stability windows, and mechanical properties. This article delves into the intrinsic mechanisms of PEO-based SPEs, analyzes the genesis of their current limitations, and summarizes the progress in research strategies that modify PEO-based SPEs through the fabrication of composite solid electrolytes.