Ni-doping to improve the performance of LiFeBO3/C cathode material for lithium-ion batteries

Ni-doping is used to improve the performance of LiFeNiBO3/C for the first time. The structure and electrochemical properties of as-prepared Ni-doped samples (LiFe1-xNixBO3/C) are investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscope, electrochemical impedance spectroscopy, and galvanostatic charge-discharge tests. The results show that LiFe1-xNixBO3/C composites consisted of similar spherical particles are linked and well-coated by nano-carbon frameworks, forming a multi-layer core-shell structure. Moreover, the substitution content of iron by nickel has significant effect on the electrochemical characteristics, especially for the rate performance. Particularly, the LiFe0.94Ni0.06BO3 shows the best electrochemical property, exhibiting a discharge capacity of 201.5 mAh g−1 at a current density of 10 mA g−1. The results indicate that Ni doping in LiFeBO3/C can effectively enhance the electrochemical performance, especially at a high charge/discharge rate.