Li-La-Zr-O固态电解质包覆对富锂锰基层状正极材料性能影响

Li-rich Mn-based layered oxide Li1.188Ni0.198Co0.087Mn0.553O2 (LMO) material was successfully coated with Li-La-Zr-O solid electrolyte (LLZO) by sol-gel process. Both LLZO-coated LMO and pristine materials were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and electrochemical impedance spectroscopy (EIS) to explore the effect of LLZO coating layer. Galvanostatic charge-discharge tests indicate that after 450 cycles at 1 C, the 2 wt% LLZO-coated LMO material (LMO@LLZO) exhibits a significant cycle stability of 193 mAh g-1 capacity with a capacity retention of 84.8 % compared to the LMO material of 125.4 mAh g-1 capacity with a capacity retention of 54.1 %. This is because the Li-La-Zr-O coating layer improve the surface stability and suppressed side reactions. In addition, the 2 wt% LLZO coating layer could also improve the rate performance of the electrode by obviously reducing interfacial charge-transfer resistance.)