Sea urchin shaped α-MnO₂/RuO₂ mixed oxides nanostructure as promising electrocatalyst for lithium-oxygen battery

α-MnO₂/RuO₂ mixed oxides in the form of sea urchin shaped nanostructures were synthesized in the weight ratio of 82:18 via a simple hydrothermal method. The synthesized α-MnO₂/RuO₂ urchin nanostructure was constructed with several straight and radially grown nanorods, and composed of homogeneously distributed MnO₂ and RuO₂ nanoparticles. When the α-MnO₂/RuO₂nanostructure was applied for air cathode catalyst, it displayed superior cyclic performances of lithium air battery with stable specific capacity, decreased overpotential and good retention rate. The α-MnO₂/RuO₂ urchin nanostructure exhibited excellent bifunctional electrocatalytic activity for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Linear sweep voltammetry study confirmed that the α-MnO₂/RuO₂ nanostructure possesses catalytic performance comparable to that of commercial Pt/C for the ORR, while it exhibits lower onset potential and higher limiting current than those of commercial Pt/C for the OER.