Uniform MnO₂ nanostructures supported on hierarchically porous carbon as efficient electrocatalysts for rechargeable Li-O₂ batteries

Through in situ redox deposition and growth of MnO₂ nanostructures on hierarchically porous carbon (HPC), a MnO₂/HPC hybrid has been synthesized and employed as cathode catalyst for non-aqueous Li-O₂ batteries. Owing to the mild synthetic conditions, MnO₂ was uniformly distributed on the surface of the carbon support, without destroying the hierarchical porous nanostructure. As a result, the as-prepared MnO₂/HPC nanocomposite exhibits excellent Li-O₂ battery performance, including low charge overpotential, good rate capacity and long cycle stability up to 300 cycles with controlling capacity of 1, 000 mAh·g^-1. A combination of the multi-scale porous network of the shell-connected carbon support and the highly dispersed MnO₂ nanostructure benefits the transportation of ions, oxygen and electrons and contributes to the excellent electrode performance.