The Synthesis and Application of Llzo Ultrathin Electrolyte Film

Abstract

Compared with a conventional lithium-ion battery, all-solid-state battery exhibits excellent safety, which is the one of drawbacks of the conventional lithium-ion battery. The Garnet electrolyte Li7La3Zr2O12 (LLZO), as the typical representative of solid electrolyte, shows outstanding safety and electrochemical stability. During the process of this work, the LLZO underwent the changes from micro-sized particles, nano-particles slurry, and the final ultrathin film. The micro-sized particles was obtained by the conventional solid state reaction. Nanoscale LLZO slurry was prepared using high energy ball-milling technology, with the addition of 1-Methyl-2-pyrrolidinone, LiN(CF3SO2)2, SPEEK-PSI-Li and Piuronic®F127. The LLZO ultrathin electrolyte film was obtained by the method of wet coating and drying out the solvent of LLZO slurry. The as-prepared LLZO ultrathin film, with a thickness of several micrometers, was applied in the cell of Li/LLZO/LFPO. At room temperature, the battery showed a capacity of 160.4 mAh g-1 for the first discharge, which was about 94.4% of the theoretical capacity value. After 100 cycles, the cell provided a discharge capacity of 136.8 mAh g-1. At 60 ℃, the battery presented more stable electrochemical performance. The capacity loss during the cycles form the 2nd to 100th was only 0.06% (0.7 mAh g-1). The excellent performance could be attributed to the ultrathin solid electrolyte film.