An oxygen cathode with stable full discharge–charge capability based on 2D conducting oxide

Abstract

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.