Co₃O₄-CeO₂/C as a Highly Active Electrocatalyst for Oxygen Reduction Reaction in Al-Air Batteries

Developing high-performance and low-cost electrocatalysts for oxygen reduction reaction (ORR) is still a great challenge for Al-air batteries. Herein, CeO₂, a unique ORR promoter, was incorporated into ketjenblack (KB) supported Co₃O₄ catalyst. We developed a facile two-step hydrothermal approach to fabricate Co₃O₄-CeO₂/KB as a high-performance ORR catalyst for Al-air batteries. The ORR activity of Co₃O₄/KB was significantly increased by mixing with CeO₂ nanoparticles. In addition, the Co₃O₄-CeO₂/KB showed a better electrocatalytic performance and stability than 20 wt % Pt/C in alkaline electrolytes, making it a good candidate for highly active ORR catalysts. Co₃O₄-CeO₂/KB favored a four-electron pathway in ORR due to the synergistic interactions between CeO₂ and Co₃O₄. In full cell tests, the Co₃O₄-CeO₂/KB exhibited a higher discharge voltage plateau than CeO₂/KB and Co₃O₄/KB when used in cathode in Al-air batteries.