Bimetallic CuCo@Nitrogen/Carbon Nanoparticles as a Cathode Catalyst for Magnesium-Air Batteries

Mg-air batteries are regarded as one of the most promising electrochemical energy storage and conversion devices. Developing high-performance, low-cost and durable non-noble metal electrocatalysts for oxygen reduction reaction (ORR) at cathode is extremely critical for promoting the practical applications of Mg-air batteries. The bimetallic M-N-C catalysts possess the superior ORR activity and stability due to the synergetic effect of metal atoms. Herein, prussian blue analogues (PBA) were employed as precursors to prepare bimetallic M-N-C electrocatalysts. The CuCo@N/C and Co@N/C were derived from CuCo-PBA and CoCo-PBA calcined under different temperatures. The bimetallic CuCo@N/C nanoparticles pyrolyzed at 800 degrees C (CuCo@N/C-800) displays superior ORR performances and outstanding stability in alkaline and neutral electrolytes. The primary Mg-air batteries assembled with the CuCo@N/C-800 as the cathode catalyst displays better discharge performances than that of Co@N/C-800. This work provides an effective strategy to synthesize bimetallic and non-noble ORR catalysts for Mg-air batteries.