Synthesis of carbon-based CoV electrocatalyst and its application in Zn-air battery devices

Precious metal catalysts are generally considered to be the best electrocatalysts for slow four-electron transfer mechanism in oxygen reduction and oxygen evolution reactions. However, its large-scale commercialization is limited due to its high cost, scarce resources and lack of stability. Therefore, under the same catalytic performance conditions, low cost and environmentally friendly non-noble metal electrocatalyst will become the focus of future electrocatalyst engineering. Dicyandiamine was used for carbon resource to prepare CoV-based carbon nanotube composites (named CoV-NC) by means of group coordination combined with freeze drying strategy and carbonization treatment. The morphology and structure of the sample was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and N 2 adsorption-desorption curve. In 0.1 M KOH electrolyte, the E onset potential of CoV-NC catalyst for ORR is 0.931 V, and the limiting current density is higher. The OER voltage is only 1.63 V at the current density of 10 mA·cm -2 , demonstrating that CoV-NC exhibits good catalytic activity of ORR and OER. As for an air-cathode material to assemble primary Zn-air battery, it can discharge continuously for 166 h at a current density of 5 mA·cm -2 , which is much better than commercial Pt/C catalyst.