Highly rechargeable lithium oxygen batteries cathode based on boron and nitrogen co-doped holey graphene

Abstract

Heteroatoms doped carbon based materials with enhanced catalytic properties hold great potential in energy storage applications, including rechargeable lithium oxygen batteries (LOBs). However, large-scale production of heteroatoms co-doped carbon with high-level dopants as well as the precise control of uniformly distributed dopant location remain challenges. Holey graphene as an emerging carbon based material has attracted increased attention as cathode for LOBs due to its nanoholes through the graphene nanosheet basal plane. Apart from the given rapid diffusion channels for mass (e.g., O2 and Li+ ), the nanoholes also provide rich egdes for the mass adsorption and storage as well as the heteroatoms doping. Herein, we report an environment-friendly and simple approach to mass production of hG with abundant in-plane nanoholes via direct oxidation of reduced graphene oxides (rG) by a controlled flow gas of H2O. Based on the obtained hG, 3.0 at.% B and 2.1 at.% N atoms are further co-doped into the hG to form B, N-hG. Benefiting from its holey structures and the synergistic effect of B and N, the B, N-hG as cathode for LOBs displays promising properties with a maximum discharge capacity of 15340 mAh g−1 and long cycling stability over 117 cycles.