Physical and electrochemical performance of LiNi_1/3Co_1/3Mn_1/3O₂ cathodes coated by Sb₂O₃ using a sol–gel process

Sb₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials have been prepared using a sol–gel process. The surface-coated cathode materials have been physically characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). The electrochemical characteristics have been investigated by electrochemical impedance spectroscopy (EIS), galvanostatic cycler, and cyclic voltammetry (CV). Moreover, the Sb₂O₃ coating does not affect the crystal structure of LiNi_1/3Co_1/3Mn_1/3O₂ but instead form a thin compact layer on the surface. The 1wt% of Sb₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathode coated shows stable cyclability with capacity retention of 98% after the 30 cycles, which is higher than the bare and 2 wt% Sb₂O₃-coated cathodes and the EIS and CV tests illustrate the suppressed charge transfer resistance and good reversibility for the optimized coating concentration on the cathode. - Highlights: • We successfully prepared Sb₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathodes by a sol–gel process. • Sb₂O₃ has been used as an additive to give a protection layer from HF attack. • Electrochemical performance of 1 wt% Sb₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ was superior. • 1 wt% Sb₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathodes reveal good cyclability at high rates