Preparation of high ionic conductivity composite solid electrolyte with in-situ synthesis of LLZO@ZiF-67

Abstract

PEO based solid electrolyte has high crystallinity, which seriously hinder the transport of lithium ions at room temperature, resulting in low ionic conductivity. In this paper, a high performance composite solid electrolyte membrane with LLZO@ZiF-67 as an inorganic filler and PEO as matrix was synthesized. The LLZO@ZiF-67 inorganic filler, which covered by in-situ synthesis of ZiF-67 layer on surface of LLZO, show a large specific surface area and a polyhedral structure. The introduction of LLZO@ZiF-67 effectively reduce the crystallinity of PEO, providing a continuous channel for the transport of lithium ions, which result in a ionic conductivity as high as 1.09×10−4 S cm−1 at room temperature of the composite electrolyte PLZ-20. Furthermore, the electrochemical stability and interface compatibility to lithium metal are improved. The lithium stripping/plating process at 0.1 mA cm−2 can maintain stable for more than 600 h without short circuit. In addition, the initial discharge capacity of the full battery (Li / PLZ-20 / LFP) can reach up to 141.1 mA h g−1 with retention of 91.45% after 100 cycles, which provide possibility for the application of high performance solid state battery.