Free‐Standing Tunnel‐Structured MnO2 Nanorods‐Doped with Nickel and Cobalt Cations as Bifunctional Electrocatalysts for Zn–Air Batteries

• DOI: 10.1002/admt.202301142
• Publication Date: 2023-09-04T04:49:35Z
• Authors: Xiaoying Zheng; Alonso Moreno Zuria; Mohamed Mohamedi
• Keywords: Overpotential; Oxygen evolution; Limiting current; Nanorod

Abstract The rational design of the electrocatalysts is paramount to alleviating global energy and environment crisis. Despite a bright future MnO 2 shown in storage conversion, intrinsic low electrical conductivity glooms its application electrocatalytic reactions like oxygen reduction/evolution (ORR/OER). doping strategy applied equip self‐supported with enhanced ORR/OER zinc‐air battery performance. In this work, class free‐standing nanorods arrays on carbon paper‐doped either cobalt or nickel cations are engineered through simple hydrothermal method. substitutional by Co Ni that partly replaces Mn ions [MnO 6 ] octahedra brings about Jahn–Teller distortion exhibits excellent catalytic performance for ORR OER. Indeed, reveals resulted more positive half‐wave potential (by >20 mV), higher limiting current densities, an electron transfer number close four. As OER, not only decreases overpotential at 10 mA cm −2 but also enhancement density 1.76 V six times greater than undoped catalyst. An optimal concentration 0.25 molar ratio Co/Mn Ni/Mn discovered based bifunctionality. Homemade rechargeable Zn–air aqueous batteries assembled doped deliver peak power density, specific capacity, lower charge voltage, charge/discharge robust stability.