Synthesis and Electrochemical Properties of Hierarchical Porous (Nickel/Cobalt)-Carbonate-Hydroxide Structures

Hierarchical porous Ni-3(CO3)(OH)(4) and (NixCo1-x)(6)(CO3)(2)(OH)(8) .H2O (x=0, 1/3, 1/2, and 2/3) structures have been synthesized via a hydrothermal route. The chloride ions in the precursor play an important role in the morphology of (Ni,Co)(6)(CO3)(2)(OH)(8) .H2O. The formation mechanism and growth process of urchin-like (Ni,Co)(6)(CO3)(2)(OH)(8) .H2O structure was investigated by adjusting the reaction time. The electrochemical properties of the products depend on the chemical composition and surface property. Ni-3(CO3)(OH)(4) exhibits higher specific capacitance at a low current density due to its porous structure and larger specific surface area. However, its rate property and cycle stability are much poorer. Co-6(CO3)(2)(OH)(8) .H2O nanorod-assembled structure possesses better cyclic performance but lower specific capacitance. (Ni,Co)(6)(CO3)(2)(OH)(8) .H2O electrodes behave improved rate property and cycle stability in comparison with Ni-3(CO3)(OH)(4), and higher specific capacitance than Co-6(CO3)(2)(OH)(8) .H2O, which can be attributed to the synergistic effect of bimetal species and unique surface property.

Automated summary

Hierarchical porous structures of Ni-3(CO3)(OH)(4) and (NixCo1-x)(6)(CO3)(2)(OH)(8) .H2O were synthesized via a hydrothermal route, with chloride ions playing a crucial role in the morphology of the (Ni,Co)(6)(CO3)(2)(OH)(8) .H2O structures. The electrochemical properties of the products were found to be influenced by their chemical composition and surface property, with Ni-3(CO3)(OH)(4) exhibiting higher specific capacitance but poorer rate performance and cycle stability compared to (Ni,Co)(6)(CO3)(2)(OH)(8) .H2O.