Enhanced cycling performance of Al-substituted α-nickel hydroxide by coating with β-nickel hydroxide

► β-nickel hydroxide-coated Al-substituted α-nickel hydroxide as cathode material for Ni−MH battery is first reported. ► The coated Al-substituted α-nickel hydroxide combines both the advantages of α-nickel hydroxide and β-nickel hydroxide. ► The enhancement of the capacity retention of coated Al-substituted α-nickel hydroxide is significant.