Ball-milled Ni-Mn-Zn hydroxide for alkaline secondary battery

In our previous study, Mn-substituted nickel hydroxide (Ni0.8Mn0.2(OH)2) was prepared by a simple ball milling method to reduce the cost of nickel hydroxide for alkaline secondary battery, but compared to the Ni(OH)2 electrode, the Ni0.8Mn0.2(OH)2 one showed an obvious decrease in its discharge potential. In this paper, Zn and Mn co-substituted nickel hydroxide (Ni0.8Mn0.2 − xZnx(OH)2, x = 0–0.075) is prepared by ball milling. The results of the cyclic voltammetry (CV) tests illustrate that the co-reduction of Mn(IV) to Mn(III) and NiOOH is observed on the Ni0.8Mn0.2 − xZnx(OH)2 electrodes, and it has a lower reduction potential than NiOOH. The co-substitution of Zn can effectively increase the co-reduction potential. The ball-milled Ni0.8Mn0.15Zn0.05(OH)2 electrode has a similar capacity (about 270 mAh g−1 at a 0.2C rate) and cycling durability to the commercial Ni(OH)2 with ball milling treatment, but the former has better high-power performance.