A partially Fe-substituted perovskite electrode for enhancing Zn-CO₂ batteries

Aqueous Zn-CO₂ batteries are a new technology for reducing carbon dioxide emissions and converting CO₂ into valuable products. The development of high-performance catalysts is crucial for improving the efficiency of the CO₂ reduction reaction(CO₂RR) in these batteries. The technical challenges of CO₂RR catalysts include high cost, complicated synthesis and low Faraday efficiency. In this study, we developed an efficient and cost-effective CO₂RR perovskite catalyst, by partially substituting Fe to the B site of precious metal-free La_0.5Sr_0.5MnO₃ (LSM) perovskite. Comprehensive investigation into the Structure, morphology, coordination information and electrochemical performance of pristine La_0.5Sr_0.5MnO₃ (LSM) and substituted La_0.5Sr_0.5Fe_0.6MnO₃ (LSF_0.6M) catalysts were conducted, LSF_0.6M catalyst shows enhanced electrochemical performance, Faraday efficiency, battery durability and battery power density than LSM. Specifically, the Fe-doped catalyst shows a significant improvement in CO₂ reduction reaction (CO₂RR) performance, with an 80% increase in current density, an 82% Faraday efficiency, and a 50% increase in power density of Zn-CO₂ battery. Characterization experimental results and DFT calculation reveal that Fe substitution can increase the perovskite lattice size to favor CO₂ absorption and *COOH formation, thus the improved CO yields. These analyses provided insights into the underlying mechanisms of the catalyst's performance in CO₂RR within the battery system. These results highlight LSF_0.6M perovskite as a very promising CO₂RR electrocatalyst for Zn-CO₂ battery.