PEO/PVDF–HFP/LLZTO Composite Solid Polymer Electrolyte for High-Performance All-Solid-State Lithium Metal Batteries
Huihui Gan, Jiajun Sun, Xia Ye, Pengyuan Qiu, Liang Li, Wen Zhu
Abstract
A composite solid polymer electrolyte (CSPE) is the best candidate in all-solid-state lithium metal batteries because of its flexibility, high safety, wide electrochemical stability, relatively high ionic conductivity, and excellent compatibility with the lithium metal. In this work, the garnet-type Li 6.75 La 3 Zr 1.75 Ta 0.25 O 12 (LLZTO) is introduced into a poly(ethylene oxide) (PEO)/poly(vinylidene fluoride–hexafluoropropylene) (PVDF–HFP)-based CSPE (PEO/PVDF–HFP/LLZTO CSPE). The PEO/PVDF–HFP/LLZTO CSPE possesses a high lithium-ion transference number of 0.47, a high ionic conductivity of 2.65 × 10 –4 S cm –1, a wide electrochemical window of 5.55 V vs Li + /Li, and effective inhibition of lithium dendrite growth for 1000 h with a current density of 0.10 mA cm –2 . Furthermore, the Li//LiFePO 4 cell assembled with the PEO/PVDF–HFP/LLZTO CSPE delivers superior rate capability and good cycling stability. Therefore, the PEO/PVDF–HFP/LLZTO CSPE is a very promising candidate for high-performance all-solid-state lithium metal batteries.