Solid electrolytes receive widespread attention due to their high safety, high energy density and simplicity of processing. However, the poor interface stability between the solid electrolyte and the electrode leads to a significant increase in interface resistance, greatly reducing the electrochemical performance of lithium-ion batteries (LIBs). Here we designed and prepared a new type of solid composite electrolytes (SCEs), which were composed of poly (ethylene oxide) (PEO) blended with poly (vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) and doped with cubic phase Li6.7La3Zr1.7V0.3O12 (LLZVO) particles. Compared with our previous work, the addition of PVDF-HFP can further reduce the crystallinity of PEO, limit the formation of lithium dendrites, and make the electrolyte/electrode interface more stable. The SCEs had better ionic conductivity of 2.04 × 10-4 S cm−1 and 2.03 × 10-3 S cm−1 at 30 ℃ and 80 ℃, respectively, and the Li/SCEs/Li symmetrical battery cycled for 1800 h without short circuit. Moreover, the coulombic efficiency of LiFePO4/SCEs/Li battery remained at 98 % after 300 cycles. This opens up a new direction for the research of garnet-type composite solid electrolytes with lower interface resistance.
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