The influence of transformation pH value on the performance of nano-scale Ni(OH)2 was analyzed. The measurement results of XRD and TEM indicate that the samples are composed of β-Ni(OH)2 with crystal size of 20-50 nm, and the crystal lattice parameters of nano-scale Ni(OH)2 prepared at different transformation pH values are different. With the increase of transformation pH value, the agglomeration of nano-scale Ni(OH)2 becomes obvious. Cyclic voltammograms(CV) and electrochemical impedance spectroscopy(EIS) measurement results show that transformation pH value affects the proton diffusion coefficient(D) and charge-transfer resistance(Rct) of the material. The specific capacity is up to 327.8 mA·h/g, and the discharge performance of electrodes depends on both D and Rct, so the kinetic characteristics that electrodes reaction is controlled by both mass-transfer step and charge-transfer step was put forward.
The influence of transforming pH values on the electrochemical performance of nano-scale Ni(OH)2 was analyzed. The measurement results of XRD indicate that the nano-scale Ni(OH)2 prepared at different transformations of pH value is β(Ⅱ)-phase with different crystal lattice parameters. Cyclic voltammograms(CV) and electrochemical impedance spectroscopy(EIS) measurement results show that transformations of pH value affect the proton diffusion coefficient (D) and charge-transfer resistance (Rct) of the material. The simulation of cell experiment shows that the sample prepared at a pH of 10.1 exhibits the maximum specific capacity (327.8 mAh/g) and higher discharge platform, the discharge performance of electrodes depends on both D and Rct, so the kinetics characteristics that electrodes reaction is controlled by both mass-transfer step and charge-transfer step are put forward.
