Enhanced Electrochemical Performance of Nickel-Rich Cathode Materials by Surface Modification with Al2O3–ZrO2 for Lithium Ion Batteries

Abstract

Al2O3–ZrO2 was coated on the surface of nickel-rich cathode materials by the sol–gel method to improve its electrochemical performance. The nanometer-thick Al2O3–ZrO2 coating layer refrains the side reaction between the electrolyte and the electrode, thus preventing the collapse of LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 layered structure and protecting the stability of the material. The electrochemical test shows that LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 coated with Al2O3–ZrO2 has good cycle and rate performance. Under the cut-off voltage of 2.8–4.5[Formula: see text]V, LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 coated with Al2O3–ZrO2 delivered an initial capacity which was 166.7[Formula: see text]mAh[Formula: see text]g[Formula: see text]at 1C (200[Formula: see text]mAh[Formula: see text]g[Formula: see text] rate, and the capacity retention rate was 77.7% after 200 cycles. The pristine LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 delivered an initial capacity which was 166.4[Formula: see text]mAh[Formula: see text]g[Formula: see text] at 1C rate, and the capacity retention rate was 51.7% after 200 cycles. The EIS and CV provided the enhanced electrochemical performance of LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 coated with Al2O3–ZrO2 which was due to accelerating Li[Formula: see text] diffusion of nickel-rich materials and electrolytes.