Ruthenium decorated hierarchically ordered macro–mesoporous carbon for lithium oxygen batteries

Abstract

Design and synthesis of functional cathode materials with superior catalytic activity are still a major challenge for non-aqueous Li–O₂ batteries. Herein, we developed a ruthenium-decorated hierarchically ordered macro–mesoporous carbon (MmC@Ru) via a mixed template method. The as-prepared MmC@Ru exhibits an ordered macroporous carbon skeleton with well-distributed mesopores, which are uniformly decorated by Ru nanoparticles. Cathodes made of MmC@Ru can provide enough room to accommodate the discharge products, facilitate the oxygen and electrolyte diffusion and then reduce the charge and discharge overpotential. As evaluated by electrochemical tests, it was found that the MmC@Ru cathode presents a high specific capacity of 12 400 mA h g⁻¹ at a current density of 200 mA g⁻¹ and an excellent cycling performance up to 100 cycles at 400 mA g⁻¹ with the restricted capacity at 1000 mA h g⁻¹.