Synthesis of High Specific Surface Area Co–Ni(OH)2 by a Self-Template Secondary Growth Method and Its Application as a Cathode Material in the Nickel Metal Hydride Battery

Abstract

Nickel hydroxide is one of the most important electrode materials for nickel–metal hydride (Ni-MH) batteries, Li-ion batteries, and supercapacitors. However, large-scale synthesis of high-performance nanonickel hydroxide materials at a low cost still remains a significant challenge. Here we report a scalable, simple, and low cost self-template secondary growth method to synthesize Co-doped nickel hydroxide (Co–Ni(OH)2). After secondary growth, the specific surface area of the product increased from 11.71 m2/g up to 102.4 m2/g, and the yield increased more than 36%. The obtained Co–Ni(OH)2 exhibits a high specific capacity of 360 mAh/g at a discharge current density of 45 mA/g, as well as excellent cycling stability and high-rate capability as a cathode material for Ni-MH batteries. Through this self-template secondary growth method, we successful increased the specific surface area of the product and reduced the waste of raw materials, and the product exhibited excellent electrochemistry.