A two-dimensional conducting oxide nanosheet, which was prepared by a two-step process involving exfoliation and heat treatment, was employed as a Li–O2 cathode without adding any conductive additives. The 2D nanostructures in the Li–O2 cathode can provide a large surface-to-mass ratio, increase the electrode–electrolyte contact area and facilitate oxygen diffusion and electron transmission. The as-synthesized conducting oxide nanosheet of RuO2 enables the Li–O2 cathode to be operated under full discharge–charge conditions, and to deliver a high specific capacity of ∼900 mA h g−1 with stable discharge–charge overpotentials (0.15/0.59 V) over 50 cycles.
