Hollow multishelled structural ZnO fillers enhance the ionic conductivity of polymer electrolyte for lithium batteries

摘要

Abstract Composite polymer electrolyte (CPE) with ceramic fillers has gained great attention for lithium batteries with high energy density and safety. However, the agglomeration of ceramic fillers and weak polymer-ceramic interaction induces limited ionic conductivity and hinders its implementation. Here, hollow multishelled structure (HoMS) ZnO with a size range of 700 ~ 900 nm is designed as fillers for polyethylene oxide (PEO)-based CPE. Strong chemical and mechanical interaction between PEO and ZnO HoMS enable a high ionic conductivity and good electrochemical and mechanical stability. Wherein, double-shelled ZnO HoMS exhibits a good ionic conductivity of 1.04 × 10−4 S∙cm−1 and 1.2 × 10−3 S∙cm−1 at 30 ℃ and 60 ℃. Additionally, all-solid-state LiFePO4/Li full cell adopted with ZnO HoMS filled CPE exhibits a high initial specific capacity of 169 mAh∙g−1 and good cycling stability and withstands abuse test. The enhanced performance is due to that HoMS provides PEO with faster ion transport channels, more effective Lewis acid-based interaction sites, suppressed PEO crystallinity, and improved ionic conductivity.