Homogeneous precipitation of α-phase Co–Ni hydroxides hexagonal platelets

This paper describes the synthesis of α-phase Co–Ni hydroxides hexagonal platelets through homogeneous precipitation, using hexamethylenetetramine (HMT) or urea as a hydrolytic agent. In the CoCl2–NiCl2–HMT system, pure α-phase can be synthesized at the concentrations of both metal ions higher than 20 mM, while in the CoCl2–NiCl2–urea system, the formation of pure α-phase is independent of the concentrations of the metal ions. When using HMT, monodisperse hexagonal platelets of α-phase Co–Ni hydroxides can be produced in the presence of polyvinylpyrrolidone (PVP). Cyclic voltammogram curve of the hexagonal platelets prepared with HMT demonstrates electrochemical performance superior to that of urea.

Graphical abstractMonodisperse hexagonal platelets of α-phase Co–Ni hydroxides, synthesized with hexamethylenetetramine as hydrolytic agent and in the presence of polyvinylpyrrolidone, exhibit better electrochemical performance as compared to that with urea as hydrolytic agent.Figure optionsDownload full-size imageDownload as PowerPoint slide