Engineering nanostructured Ag doped α-MnO(2) electrocatalyst for highly efficient rechargeable zinc-air batteries

Engineering of highly active, and non-precious electrocatalysts are vital to enhance the air-electrodes of rechargeable zinc-air batteries (ZABs). We report a facile co-precipitation technique to develop Ag doped α-MnO(2) nanoparticles (NPs) and investigate their application as cathode materials for ZABs. The electrochemical and physical characteristics of α-MnO(2) and Ag doped α-MnO(2) NPs were compared and examined via CP, CV, TGA/DTA, FT-IR, EIS, and XRD analysis. CV result displayed higher potential and current for ORR in Ag doped α-MnO(2) NPs than α-MnO(2); but, ORR performance decreased when the Ag doping was raised from 7.5 to10 mmol. Moreover, α-MnO(2) and Ag doped α-MnO(2) NPs showed 2.1 and 3.8 electron transfer pathway, respectively, showing Ag doped α-MnO(2) performance to act as an active ORR electrocatalyst for ZABs. The EIS investigation exhibited that charge-transfer resistance for Ag doped α-MnO(2) was extremely lower associated to the MnO(2) demonstrating that the successful loading of Ag in α-MnO(2). A homemade ZAB based on Ag–MnO(2)-7.5 showed a high open circuit potential, low ohmic resistances, and excellent discharge profile at a constant current density of 1 mA/g. Moreover, Ag–MnO(2)-7.5 show a specific capacity of 795 mA h g(−1) with corresponding high energy density ∼875 Wh kg(−1) at 1 mA cm(−2) discharging conditions.