Prussian Blue Analogues Derived CuO@Co3O4 Nanoparticles As Effective Oxygen Reduction Reaction Catalyst For Magnesium-Air Battery

Abstract

Developing efficient, durable and cost-effective non-noble metal catalysts for oxygen reduction reaction (ORR) is remarkably significant to promote the efficiency and performance of Mg-air battery. Herein, the CuO@Co3O4 nanoparticles are synthesized by a low-cost and simple approach using the CuCo-based prussian blue analogues (PBA) as precursor of pyrolysis at different calcination temperatures. It is found that the CuO@Co3O4 nanoparticles calcined at 600 ºC (CCO-600) have relatively small size and superior ORR performance. The onset potential is 0.889 V and the diffusion limiting current density achieves 6.746 mA·cm-2, as well as prominent stability in 0.1 M KOH electrolyte. The electron transfer number of the CCO-600 is 3.89 under alkaline medium, which manifests that the reaction mechanism of ORR is dominated by 4 e process. It is similar to the commercial Pt. Moreover, the primary Mg-air battery with the CCO-600 as the cathode catalyst has been assembled. The Mg-air battery of the CCO-600 as the cathode catalyst possesses better discharge performance than the CuCo-based PBA. The open circuit voltage of CCO-600 arrives 1.76 V and energy density of 1895.95 mWh/g. This work provides an effective strategy to develop non-noble metal ORR catalyst for the application of metal-air batteries.