Structural and electrochemical performance of additives-doped alpha -Ni(OH) sub(2)

The additives-doped alpha -nickel hydroxides were prepared by supersonic co-precipitation method. The crystal structure and grain size of the prepared samples were characterized by X-ray diffraction (XRD) and Particle size distribution (PSD), respectively. Cyclic voltammetry (CV) tests show that Al-Co-Y doped Ni(OH) sub(2) has better reaction reversibility, higher proton diffusion coefficient than those of Al-Co doped Ni(OH) sub(2). Al-Co-Y doped Ni(OH) sub(2) also has lower charge-transfer resistance as shown by electrochemical impedance spectroscopy (EIS). Charge/discharge tests show that the discharge capacity of Al-Co-Y doped Ni(OH) sub(2) reaches 328 mAh/g at 0.2 C and 306 mAh/g at 0.5 C, while Al-Co doped Ni(OH) sub(2) can only discharge a capacity of 308 mAh/g at 0.2 C and 267 mAh/g at 0.5 C.