A Study on Crystalline Structure and Li+-Ion Diffusion Coefficient of LiNixFe1−xPO4/C Cathode Material

This work focused on synthesising Ni-doped LiNi x Fe 1− x PO 4 /C ( x = 0, 0.05 and 0.1) cathode materials by hydrothermal method. The crystalline structure and morphology of the synthesised materials were investigated through x-ray diffraction, Raman scattering spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. Their electrochemical performance was analysed by cyclic voltammetry and galvanostatic cycling test. The highest initial capacity of 170.3 mAh/g was achieved for LiNi 0.1 Fe 0.9 PO 4 /C. It also maintained 99.68% of its initial capacity for 120 cycles, with a Li + -ion diffusion coefficient of 1.12 × 10 −12 cm 2 /s compared with that (9.21 × 10 −13 cm 2 /s) of LiNi 0.05 Fe 0.95 PO 4 /C.