Hexagonal Cadmium Sulfide Cathode for Aqueous Zinc-Ion Battery: Study of Zinc-Sulfide Formation and Zn/CdS Battery Stability

We report facile coprecipitation synthesis of binary chalcogenide cadmium sulfide (CdS), which has been used as an efficient cathode for aqueous zinc-ion batteries. Pure phase hexagonal CdS was synthesized using an alkaline pH-based coprecipitation method. Structural properties, electronic properties and morphological and electrochemical analysis of the single electrodes’ & Zn/CdS cell performance were studied using relevant state-of-the-art techniques. Determination of the compatibility of the cathode CdS with the Zn anode was carried out by band alignment of the cathode CdS and anode Zn, which was studied by cyclic voltammetric analysis. The high operating potential of 1.45 was obtained for the Zn/CdS system, during the discharge formation of ZnS, which occurs at the cathode because of the Zn²⁺ cation intercalation. The bond formation and cohesive forces were studied by the Born–Haber approach and the generalized Kapustinskii equation explaining the formation of Zn–S bonds. The galvanostatic charge–discharge (GCD) cyclic performance analysis was carried out for the Zn/CdS system with a high capacity of ∼159 mAh/g.