Enhanced Oxygen Redox Kinetics and Stability in Li−O₂ Batteries Using Trimetallic MnCo_2‐xCu_xO₄ Spinel Catalysts

Abstract High energy density rechargeable Li−O 2 batteries (LOBs) have garnered significant attention as a promising energy storage device. However, the sluggish oxygen redox kinetics impeded the efficiency and cycling performance during both the charge and discharge processes. To address this issue, we introduce a non‐noble‐trimetallic MnCo 2‐x Cu x O 4 (X=0 to 1) spinel interface as a bifunctional catalyst, to improve the reaction kinetics and cycle stability of LOBs. The half‐filled e g orbital improves the synergistic interaction between Cu + /Cu 2+ , Co 2+ /Co 3+ , and Mn 3+ /Mn 4+ redox pairs in the lattice, which enhances catalytic performance. In the series of MnCo 2‐x Cu x O 4 (X=0 to 1) spinel catalyst MnCo 1.75 Cu 0.25 O 4 (MCU25) emerged as a standout performer. This exhibited notable half‐cell performance, featuring superior ORR/OER bifunctional electrocatalytic activity with a ΔE of 1.15 V (vs RHE). Notably, the MCU25 cathode exhibited remarkable stability for over 1250 hours, enduring 225 cycles at 500 mA h g −1 and stable up to 70 cycles at a capacity limit of 1000 mA h g −1 in LOBs. Furthermore, it demonstrated an exceptional discharge‐specific capacity of 11272 mA h g −1 at a current density of 175 mA g −1 , exceeding the performance achieved by state‐of‐the‐art RuO 2 around 10180 mA h g −1 .