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 RuO 2 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 RuO 2 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 RuO 2 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 RuO 2 particles. The Li 2 O 2 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. Unlabelled Image • A 3D intersected graphene nanoribbons skeleton is prepared by chemical shear. • The ORR performance of the cell with GNRs is better than that with MWCNTs. • The battery with RuO 2 @GNRs shows an excellent cycling stability of 424 cycles. • The deposition of Li 2 O 2 shows two totally different morphologies on GNRs and MWCNTs. • The strip-like Li 2 O 2 deposited on the quasi-1D GNRs obeys conformal growth mode. [ABSTRACT FROM AUTHOR]