One-Dimensional RuO sub(2)/Mn sub(2)O sub(3) Hollow Architectures as Efficient Bifunctional Catalysts for Lithium-Oxygen Batteries

Rational design and massive production of bifunctional catalysts with fast oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics are critical to the realization of highly efficient lithium-oxygen (Li-O sub(2)) batteries. Here, we first exploit two types of double-walled RuO sub(2) and Mn sub(2)O sub(3) composite fibers, i.e., (i) phase separated RuO sub(2)/Mn sub(2)O sub(3) fiber-in-tube (RM-FIT) and (ii) multicomposite RuO sub(2)/Mn sub(2)O sub(3) tube-in-tube (RM-TIT), by controlling ramping rate during electrospinning process. Both RM-FIT and RM-TIT exhibited excellent bifunctional electrocatalytic activities in alkaline media. The air electrodes using RM-FIT and RM-TIT showed enhanced overpotential characteristics and stable cyclability over 100 cycles in the Li-O sub(2) cells, demonstrating high potential as efficient OER and ORR catalysts. Keywords: Bifunctional; electrocatalysts; manganese oxide; ruthenium oxide; lithium-oxygen batteries; electrospinning