Physical and electrochemical characterization of amorphous lithium lanthanum titanate solid electrolyte thin-film fabricated by e-beam evaporation

摘要

Amorphous lithium lanthanum titanate (LLTO) solid electrolyte thin-films have been fabricated by e-beam evaporation. The effect of different e-beam power on the physical properties and electrical performance of LLTO thin-film is investigated. Higher e-beam power is a key factor to obtain good quality LLTO thin-film which has higher ionic conductivity. X-ray diffraction patterns, X-ray photoelectron spectra, scanning electron microscopy and impedance spectroscopy are used to characterize their physical and electrical properties. An all-solid-state of Li/LiPON/LLTO/ LiCoO_2 cell using LLTO thin-film as solid electrolyte exhibits the first discharge capacity of about 50 μA h/cm~2-μm and the capacity fading is about 0.5% per cycles after 100 discharge—charge cycles at discharge current of 7 μA/cm~2, demonstrating the promise of e-beam evaporation deposition for the fabrication of LLTO thin-film for all-solid-state thin-film rechargeable lithium batteries.