Co 3 O 4 Hollow Nanoparticles and Co Organic Complexes Highly Dispersed on N‐Doped Graphene: An Efficient Cathode Catalyst for Li‐O 2 Batteries

Rechargeable Li‐O 2 batteries are promising candidates for electric vehicles due to their high energy density. However, the current development of Li‐O 2 batteries demands highly efficient air cathode catalysts for high capacity, good rate capability, and long cycle life. In this work, a hydrothermal‐calcination method is presented to prepare a composite of Co 3 O 4 hollow nanoparticles and Co organic complexes highly dispersed on N‐doped graphene (Co–NG), which acts as a bifunctional air cathode catalyst to optimize the electrochemical performances of Li‐O 2 batteries. Co–NG exhibits an outstanding initial discharge capacity up to 19 133 mAh g −1 at a current density of 200 mA g −1 . In addition, the batteries could sustain 71 cycles at a cutoff capacity of 1000 mAh g −1 with low overpotentials at the current density of 200 mA g −1 . Co–NG composites are attractive as air cathode catalysts for rechargeable Li‐O 2 batteries.