Electrospinning Derived Hierarchically Porous Hollow CuCo2O4 Nanotubes as an Effectively Bifunctional Catalyst for Reversible Li–O2 Batteries

The structural engineering and design of effectively bifunctional cathode catalysts perform a vital role in enhancing the oxygen-electrode kinetics for achieving highly reversible Li–O2 batteries. Herein, one-dimensional CuCo2O4 nanotubes are fabricated by a cost-efficient electrospinning technique as a bifunctional cathodic catalyst for a lithium–oxygen battery for the first time. The as-fabricated CuCo2O4 nanotubes with hollow and hierarchically mesoporous/macroporous architecture accelerate the mass (O2 and Li+) transport and alleviate the clog of insoluble discharge products. Along with their highly intrinsic activity toward oxygen reduction and evolution reactions, the CuCo2O4 nanotubes-based lithium–oxygen battery demonstrates remarkably improved electrochemical performance, such as low overpotential, high discharge capacities (8778 mAh g–1 at 100 mA g–1), superb rate capability, and superior reversibility up to 128 cycles under a controlled capacity of 1000 mAh g–1 at 200 mA g–1. The further ex-situ SEM and XRD analyses reveal that the disk-like toroidal-shaped Li2O2 product can be efficiently decomposed during the recharging process, confirming the good reversibility of CuCo2O4 nanotubes-based cathode. These outcomes demonstrate the good prospect of CuCo2O4 nanotubes as an effectively non-noble metal catalyst in the reversible Li–O2 battery.