Ruthenium-based electrocatalysts supported on reduced graphene oxide for lithium-air batteries.

Ruthenium-based nanomaterials supported on reduced graphene oxide (rGO) have been investigated as air cathodes in non-aqueous electrolyte Li-air cells using a TEGDME-LiCF3SO3 electrolyte. Homogeneously distributed metallic ruthenium and hydrated ruthenium oxide (RuO2·0.64H2O), deposited exclusively on rGO, have been synthesized with average size below 2.5 nm. The synthesized hybrid materials of Ru-based nanoparticles supported on rGO efficiently functioned as electrocatalysts for Li2O2 oxidation reactions, maintaining cycling stability for 30 cycles without sign of TEGDME-LiCF3SO3 electrolyte decomposition. Specifically, RuO2·0.64H2O-rGO hybrids were superior to Ru-rGO hybrids in catalyzing the OER reaction, significantly reducing the average charge potential to ∼3.7 V at the high current density of 500 mA g(-1) and high specific capacity of 5000 mAh g(-1).