2D Nitrogen-Doped Carbon Nanotubes/Graphene Hybrid as Bifunctional Oxygen Electrocatalyst for Long-Life Rechargeable Zn-Air Batteries

The rational construction of efficient bifunctional oxygen electrocatalysts is of immense significance yet challenging for rechargeable metal-air batteries. Herein, this work reports a metal-organic framework derived 2D nitrogen-doped carbon nanotubes/graphene hybrid as the efficient bifunctional oxygen electrocatalyst for rechargeable zinc-air batteries. The as-obtained hybrid exhibits excellent catalytic activity and durability for the oxygen electrochemical reactions due to the synergistic effect by the hierarchical structure and heteroatom doping. The assembled rechargeable zinc-air battery achieves a high power density of 253 mW cm(-2) and specific capacity of 801 mAh g(Zn)(-1) with excellent cycle stability of over 3000 h at 5 mA cm(-2). Moreover, the flexible solid-state rechargeable zinc-air batteries assembled by this hybrid oxygen electrocatalyst exhibits a high discharge power density of 223 mW cm(-2), which can power 45 light-emitting diodes and charge a cellphone. This work provides valuable insights in designing efficient bifunctional oxygen electrocatalysts for long-life metal-air batteries and related energy conversion technologies.