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 MnO 2 and Mn 2 O 3 , 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.