Manganese coating α-Ni(OH)2 as high-performance cathode material for Ni-MH battery

The α-Ni(OH)2 coated with manganese (Mn) materials was synthesized by the chemical precipitation method, and the electrochemical properties were investigated. The results showed that the ingredient of the coating is a mixture of MnO2 and Mn2O3, and the coating can inhibit the intercalated anions escape and stabilize the α-Ni(OH)2 phase structure in KOH alkaline solution. The coated electrodes have higher discharge capacities and higher capacity retention rates than the uncoated α-Ni(OH)2 electrode, the discharge capacity of Mn-coated electrodes is over 350 mAh g−1, and the capacity retention rate exceeds 92%, separately. The reason may be that the Mn coatings can block or decelerate water molecule and the anion to escape from the interlayers, therefore prevent α phase structural collapse and maintain high discharge capacity during a long lifespan cycle. Therefore, the Mn coating α-Ni(OH)2 is a promising candidate for high-power Ni-MH batteries.