Physical characterization, electrochemical performance and storage stability of spherical Al-substituted γ-NiOOH

Spherical Al-substituted γ-NiOOH as an individual positive electrode material for a new type of alkaline primary/rechargeable Zn-NiOOH battery was prepared by the chemical oxidation of spherical Al-substituted α-Ni(OH)2. The spherical Al-substituted γ-NiOOH was characterized by XRD, SEM, FT-IR, TGA-DTG, TPD-MS and HT-XRD. The tap density and average nickel oxidation state were measured. Its electrochemical performance and storage stability were also investigated. The results show that the as-prepared spherical Al-substituted γ-NiOOH has remarkably higher specific discharge capacity and superior storage stability in alkaline electrolyte compared to spherical β-NiOOH.