A344 Journal of The Electrochemical Society, 160 (2) A344-A350 (2013) 0013-4651/2013/160(2)/A344/7/$28.00 © The Electrochemical Society Oxygen Reduction Reaction Using MnO2

Nitrogen-doped thermally exfoliated graphene (NExG) synthesized by a simple one-step method combined with α-MnO2 nanotubes (NT) is employed as air cathode materials for lithium oxygen (Li-O2) battery applications. α-MnO2 NT/NExG composite is shown to demonstrate excellent oxygen reduction reaction (ORR) activity in an aprotic non-aqueous electrolyte Li-O2 cell resulting in 2.92 V at the current density of 100 mA g−1, discharge current density of 7.2 A g−1 at 2.2 V, and the maximum power density of 15.8 W g−1 based on carbon mass. This excellent performance of the composite suggests that not only α-MnO2 NT exhibits a remarkable catalytic activity for ORR, but also NExG with a large surface area and high electrical conductivity is capable of catalyzing ORR, demonstrating an outstanding hybrid effect in an aprotic non-aqueous electrolyte Li-O2 cell