A superior composite gel polymer electrolyte of Li7La3Zr2O12- poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) for rechargeable solid-state lithium ion batteries

High-quality solid electrolyte is essential for the growing need of lithium ion batteries. Herein, we report a novel organic-inorganic composite electrolyte based on Li7La3Zr2O12 ceramic powder incorporated into PVDF-HFP through a simple combined method. At room temperature, the composite polymer electrolyte (CPE) possesses a good ionic transmission improvement of 3.71 × 10−4 S cm−1. The CPE behaves a fine lithium ion transference number of 0.58 and an electrochemical window of up to 4.65 V. CPEs display meliorative electrochemical stability compared to pure PVDF-HFP electrolyte. The cathode presents an excellent initial discharge capacity of 163.1 mAh g−1 at 0.2 C in Li/CPE/LiFePO4 cell. The cell with CPE displays much better capacity retention than that with pure PVDF-HFP electrolyte. The Li7La3Zr2O12 modified PVDF-HFP is a promising electrolyte for lithium ion batteries.