CuMnO2 Nanoflakes as Cathode Catalyst for Oxygen Reduction Reaction in Magnesium-Air Battery

Developing efficient and stable ORR catalysts for Mg-air batteries is crucial to enabling extensive applications. Herein, CuMnO2 nanoflakes were synthesized with a facile one-step hydrothermal way and applied as the cathode catalyst for Mg-air batteries. The ORR activities in alkaline and neutral electrolyte were then investigated. The half-wave potential has a minus variation of 22 mV after 5000 cycles, indicating the outstanding stability of the CuMnO2. The electron transfer number of the CuMnO2 is 3.70 under neutral condition, which demonstrates that the reaction process of ORR is equivalent to the commercial Pt catalyst. Moreover, the primary Mg-air battery with CuMnO2 as the cathode catalyst was assembled and the discharge properties were tested. The open circuit voltage achieved was 1.78 V and the operating voltage remained about 1.36 V after 22 h operation at 1.0 mA center dot cm(-2). It is evident that the CuMnO2 nanoflake is an effective catalyst to accelerate the reaction rate of ORR process in Mg-air battery. This work provides a novel approach for the subsequent exploration of non-noble metal catalysts for Mg-air batteries.

Automated summary

CuMnO2 nanoflakes synthesized through a hydrothermal method exhibited outstanding stability and efficiency when used as a cathode catalyst for Mg-air batteries. The electron transfer number of CuMnO2 under neutral conditions is comparable to commercial Pt catalyst, indicating its high ORR activity. The CuMnO2 nanoflake effectively accelerates the reaction rate of ORR process in Mg-air batteries, showing potential for further exploration of non-noble metal catalysts.