Enhanced electrochemical behavior of LiNi0.8Co0.1Mn0.1O2 cathode materials by nickel boride coating for LIB

A thin layer of nickel boride with high conductivity and stability was successfully coated on the surface of Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode materials with the assistance of polyvinyl pyrrolidone (PVP). Various characterization methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), etc., were used to characterize the as-prepared nickel boride coated LiNi0.8Co0.1Mn0.1O2 materials. An appropriate amount of nickel boride is helpful for reducing the diffusion resistance of lithium ions and the electrode polarization. Compared with the pristine [email protected] wt%Ni2B sample, the [email protected] wt%Ni2B sample coated with 0.75 wt% nickel boride possesses the best electrochemical properties. At the rate of 15C, the [email protected] wt%Ni2B sample has the discharge capacity of 159.5 mAh g−1, which is 20.1 mAh g−1 higher than that of the [email protected] wt%Ni2B sample. Moreover, the [email protected] wt%Ni2B sample has a better cycle performance than the [email protected] wt%Ni2B sample at 1C within different voltage range of both 2.8–4.3 V and 2.8–4.5 V for 100 charge/discharge cycles. The relatively better electrochemical properties of the [email protected] wt%Ni2B sample is ascribed to the lower electrochemical polarization and charge conduction impedance.