Low-cost and high-safety montmorillonite-based solid electrolyte for lithium metal batteries

Composite solid-state electrolyte have good interfacial compatibility and mechanical properties, but their safety (such as easy to catch fire) and economic cost are still problems. In present work, an composite solid-state electrolyte was prepared by inserting poly(vinylidene fluoride)-based polymer electrolyte matrix into the interlayer of a low cost clay mineral-montmorillonite. The composite electrolyte exhibited remarkable characteristics, including excellent flame retardancy, high room temperature ionic conductivity of 2.28 × 10−4 S cm−1, wide electrochemical stability window of 4.8 V, high lithium-ion transference number of 0.57 and good mechanical strength of 12.58 MPa. Furthermore, LiFePO4-based solid-state battery, utilizing this composite solid-state electrolyte, exhibited stable cycling with discharge specific capacity of 130 mAh g−1 for over 100 cycles at a rate of 0.5C at room temperature. This successful performance demonstrated the potential of utilizing low-cost and environmentally friendly raw clay mineral materials in high energy density solid-state battery applications.