Hierarchically tubular architectures composed of vertical carbon nanosheets embedded with oxygen-vacancy enriched hollow Co3O4 nanoparticles for improved energy storage

Abstract

Although great efforts have been devoted to exploiting electrode materials with designed composition and nanostructure for high-performance electrochemical energy storage devices, it remains critically challenging to achieve hierarchically tubular architectures constructed with different low-dimensional building blocks due to the lack of appropriate synthetic strategies. Herein, hierarchically tubular structures composed of vertically aligned carbon nanosheets embedded with oxygen-vacancy enriched hollow Co3O4 nanoparticles (H-Co3O4/C) are prepared. Benefited from these unique features, H-Co3O4/C electrode containing 54 wt.% carbon and 46 wt.% Co3O4 exhibits high specific capacity of 328.0 C g−1 at 1 A g−1, good rate capability with 70% capacity retained at 20 A g−1, improved energy density of 8.3 Wh kg−1 at the power density of 4268.5 W kg−1 as well as remarkable stability for 10,000 charge-discharge cycles.