RuO2-particle-decorated graphene-nanoribbon cathodes for long-cycle Li-O2 batteries

In this work, we report a novel cathode composed of three-dimensional intersected graphene nanoribbons skeleton decorated with RuO2 catalyst, where graphene nanoribbons are obtained by unzipping multi-walled carbon nanotubes. The graphene nanoribbons framework exhibits a three-dimensional intersected structure and a large specific surface area, leading to a higher capacity than multi-walled carbon nanotubes. The RuO2 introduced via a facile dropping method enhances the oxygen evolution reaction kinetics and obviously reduces the charge overpotential. More importantly, the Li-O-2 battery with RuO2 decorated graphene nanoribbons cathode presents an excellent cycling stability of 424 cycles at a curtailed capacity of 1000 mAh g(-1), which can be attributed to the synergistic effect between the intersected band-like graphene and highly effective RuO2 particles. The Li2O2 deposited on graphene nanoribbons shows a totally different surface morphology compared with that on multi-walled carbon nanotubes due to the different structures of carbon substrates. This work provides a promising design of highly efficient air electrodes for high-performance Li-O-2 batteries.