Catalytic Activities of MnO₂/RuO₂/Carbon Nanocomposites for Li-O₂ Battery Application

We report the synthesis and electrochemical characterization studies of a bifunctional catalyst suitable for lithium air battery application. MnO2 and RuO2 are supported on two different carbon supports such as graphite nanofiber(GNF) and graphene oxide(GO) to employ oxygen cathode catalyst of lithium-air batteries. MnO2/GNF is first prepared by a simple hydrothermal synthesis and is then decorated with RuO2 using a redox reaction technique. The highest electrocatalytic performance is observed from a weight ratio of RuO2:MnO2/GNF=5:5 with good cyclability and high specific capacity. Perovskite Ba0.5Sr0.5Co0.8Fe0.2O3(BSCF) decorated with palladium shows good ORR and OER activity when tested in aqueous medium (ORR onset potential : -0.072 V vs Hg/HgO, OER onset potential : 0.700 V vs Hg/HgO).