Nickel‐Nitrogen Doped MnO2 as Oxygen Reduction Reaction Catalyst for Aluminum Air Batteries

Abstract Aluminum‐air battery has the advantages of high energy density, low cost and environmental protection, and is considered as an ideal next‐generation energy storage conversion system. However, the slow oxygen reduction reaction (ORR) in air cathode leads to its unsatisfactory performance. Here, we report an electrode made of N and Ni co‐doped MnO 2 nanotubes. In alkaline solution, Ni/N‐MnO 2 has higher oxygen reduction activity than undoped MnO 2 , with an initial potential of 1.00 V and a half‐wave potential of 0.75 V. This is because it has abundant defects, high specific surface area and sufficient Mn 3+ active sites, which promote the transfer of electrons and oxygen‐containing intermediates. Density functional theory (DFT) calculations show that MnO 2 doped with N and Ni atoms reduces the reaction overpotential and improves the ORR kinetics. The peak power density and energy density of the Ni/N‐MnO 2 air electrode increased by 34.03 mW cm −2 and 316.41 mWh g −1 , respectively. The results show that N and Ni co‐doped MnO 2 nanotubes are a promising air electrode, which can provide some ideas for the research of aluminum‐air batteries.