Enhanced electrochemical performance of Li-rich layered oxide, Li1.2Mn0.54Co0.13Ni0.13O2, by surface modification derived from a MOF-assisted treatment

Abstract

We developed a promising cathode material prepared by effective surface modification of Li-rich layered oxide (LLO) materials, using a Zr-based MOF (UIO-66-F4), as a precursor to produce in-situ MOF-derived ZrO2 (MDZ) coatings. A new method for F doping on LLO was also proposed. The MOF-assisted treatment renders a uniform nanoscale coating of ZrO2 and a porous structure of Li1.2Mn0.54Co0.13Ni0.13O2 hierarchical secondary microsphere. The rate capability, cycling stability, and first coulombic efficiency of LLO were significantly improved by the MOF-assisted treatment. The discharge capacity of the MOF-derived ZrO2 coated LLO (MDZ@LLO) material was 279 and 110.0 mAh g−1 at 0.1 C and 5 C, respectively. The capacity retention increased from 71.1% to 83.8% after 200 cycles at 1 C while the coulombic efficiency increased from 62% to 72% during the first cycle. Keywords: Lithium-ion battery, Lithium-rich layered oxide material, Surface modification, Fluorine doping