First Principles Study of the Electrochemical Properties of CuO cathodes modified with Bi₂O₃ in Rechargeable Zn/CuO Batteries.

Rechargeable alkaline Zn/CuO batteries are a strong candidate for electrical energy storage applications due to their high theoretical capacity and low cost. Recent studies have shown that the addition of Bi₂O₃ and the implementation of carbon coating on CuO cathodes significantly enhances the performance and improves the cyclability of Zn/CuO batteries. We apply ab initio computational methods based on density functional theory to investigate the underlying mechanism governing the electrochemical discharge of CuO and Cu(OH)₂ cathode materials in the presence and in the absence of the Bi₂O₃ additive. The results of our calculations indicate the possibility of formation of mixed Cu and Bi oxides, such as CuBi₂O₄, that suppress the accumulation of Cu₂O in the battery cathode. Our predictions are consistent with the experimental observations that confirm the presence of CuBi₂O₄ in CuO cathodes modified with Bi₂O₃ .