Effect of in-situ doped anions on electrochemical performances of cathodically electrodeposited Ni(OH)2

In this work, the anion in situ doped nickel hydroxide nanoparticles were electrochemically synthesized by different nickel salt solution. NO3−, Cl− and SO42− can be in situ intercalated into the cathodically deposited Ni(OH)2 sample (α-phase), while CH3COO− cannot be in situ intercalated into the cathodically deposited Ni(OH)2 sample (β-phase). The doping effect on the electrochemical performances of the synthesized sample is related with both of the size and the structure characteristic of the doped anions. On one side, the enlargement of lattice spacing is beneficial to H+/OH− transfer, and on the other side, the steric hindrance effect is restrictive to H+/OH− transfer. However, the NO3− intercalated Ni(OH)2 sample has the largest lattice spacing and the highest electrochemical performances due to its special planar structure characteristic and the effect on the dissociation energy of O-H bond in the charge-discharge process of Ni(OH)2.