Ab Initio Studies of the Discharge Mechanism of CuO Cathodes Modified with Bi₂O₃ in Rechargeable Alkaline Zn/CuO Batteries

Rechargeable alkaline Zn/CuO batteries are a promising candidate for energy storage applications due to their high capacity and low cost. Recent studies have shown that the addition of Bi 2 O 3 and the implementation of carbon coating on CuO cathodes enhances the performance and improves the cyclability of Zn/CuO batteries. However, the mechanism of influence of Bi 2 O 3 on the electrochemical performance of CuO cathodes in rechargeable Zn/CuO batteries is not fully understood. We apply density functional computational methods to investigate the electrochemical discharge of CuO cathodes modified with a Bi 2 O 3 additive. Our calculations suggests that the improved performance of Zn/CuO-Bi 2 O 3 cells could be partially attributed to the formation of stable mixed Cu-Bi oxides, such as CuBi 2 O 4 , which suppress the accumulation of highly resistive Cu 2 O in the battery cathode. The results of our study are consistent with the experimental observations that confirm the presence of CuBi 2 O 4 in CuO cathodes modified with Bi 2 O 3 .