Ultrafine Mn3O4 nanowires/three-dimensional graphene/single-walled carbon nanotube composites: superior electrocatalysts for oxygen reduction and enhanced Mg/air batteries
The exploration of highly efficient catalysts for the oxygen reduction reaction to improve sluggish kinetics still remains a great challenge for advanced energy conversion and storage in metal/air batteries. In this work, ultrafine Mn3O4 nanowires/three-dimensional graphene/single-walled carbon nanotube catalysts with an electron transfer number of 3.95 (at 0.60 V vs Ag/AgCl) and kinetic current density of 21.7-28.8 mA cm-2 were developed via a microwave-irradiation-assisted hexadecyl trimethylammonium bromide (CTAB) surfactant procedure to greatly enhance the overall catalytic performance in Mg/air batteries. To match the electrochemical activity of the cathode catalysts, a large-scale Mg anode prepared with micropersimmon-like particles via a mechanical disintegrator and Mg(NO3)2-NaNO2-based electrolyte containing 1.0 wt % trihexyl(tetradecyl)phosphonium chloride ionic liquid were applied. Combining the ultrafine Mn3O4 nanowires/three-dimensional graphene/single-walled carbon nanotube as an efficient electrocatalyst for the oxygen reduction reaction and an Mg micro-/nanoscale anode in the novel electrolyte, the advanced Mg/air batteries demonstrated a high cell open circuit voltage (1.49 V), a high plateau voltage (1.34 V), and a long discharge time (4177 min) at 0.2 mA cm-1, showing a high energy density. Therefore, it is believed that this device configuration has great potential for application in new energy storage technologies.
Additional Grant Number
Please refer to publisher version or contact your library.