Fabrication of mesoporous SiO2/P(VDF-HFP) composite membrane for high-performance lithium-ion batteries

Abstract

The aim of this work is to improve the characteristics of lithium-ion batteries (LIBs) by designing and applying advanced quasi-solid electrolytes. Mesoporous silica nanorods (m-SiO2) with a high specific surface area (537.8 m2 g−1) were prepared via a sol–gel method, then compounded with poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and Li-salt (in organic solvent) to prepare composite gel electrolyte (m-SiO2/P(VDF-HFP)-GE) membrane. It exhibits strong thermal stability (∼353 °C), wide electrochemical stability window (5.3 V), excellent lithium-ion transfer number (tLi+ = 0.71) and high ionic conductivity (σ = 1.6 × 10−3 S cm−1). Meanwhile, when the m-SiO2/P(VDF-HFP)-GE membrane was assembled with LiFePO4 and Li, a long-cycling stable LIB with high-capacity (137 mA h g−1 at 0.3C) was obtained.