Synergistic ion transport facilitated by one-dimension wollastonite in solid polymer electrolytes for stable lithium metal batteries

Abstract

Solid polymer electrolytes suffer from relatively low Li+ conductivity, poor mechanical strength and interfacial incompatibility with electrodes, which hinder their further application in solid-state batteries. In this work, one-dimension (1D) wollastonite fillers are introduced into the solid polymer electrolyte, which not only contribute to the improved mechanical strength and electrochemical window, but also effectively inhibit polymer crystallization. More importantly, the abundant Lewis sites at wollastonite surface provide 1D ion pathway to boost ion transport in the electrolyte, achieving high ionic conductivity and Li+ transfer number. Owing to these favorable properties, the as-prepared polymer electrolyte exhibits enhanced interfacial stability toward Li anode, enabling long-term cycling in a Li-Li symmetric cell without short circuit. Showing good interfacial compatibility with both LiFePO4 and LiCoO2 cathode materials, the modified polymer electrolyte delivers high rate capability (143 mAh g−1 at 5C) and stable cycling performance (capacity retention of 93.12% after 380 cycles) in full cells. Through regulating the interfacial interactions between polymer matrix and fillers, this work points out a new direction towards high-performance all-solid-state batteries.