Mn Nanoparticles Encapsulated within Mesoporous Helical N‐Doped Carbon Nanotubes as Highly Active Air Cathode for Zinc–Air Batteries

Abstract

AbstractThe practical application of clean energy conversion and storage technologies, such as fuel cells and metal–air batteries, have been significantly impeded by the high cost and scarcity of precious metal catalysts used for the oxygen reduction reaction (ORR). Transitional metal/carbon compounds are a promising alternative to precious metal catalysts for the ORR. Herein, Mn nanoparticles encapsulated within mesoporous helical N‐doped carbon nanotubes (Mn@HNCNTs) are developed as highly active ORR catalysts. In terms of the onset potential and half‐wave potential for ORR, the optimized Mn@HNCNTs exhibit an excellent ORR performance, which is comparable to Pt/C. When the Mn@HNCNTs are assembled as air cathodes, with zinc foil as the anode in primary zinc–air cells, the obtained cell delivers a higher cell voltage and capacity than the zinc–air cell using Pt/C as the air cathode, as well as many reported cells using TM/CNT‐based air cathodes. The electrocatalytic performance in the zinc–air cell demonstrates that Mn@HNCNTs have great potential for use as ORR catalysts in metal–air batteries.