Autocatalysis surface-growth of Co0.85Se@carbon nanotubes on carbon nanosheets as anode material for superior lithium storage

Abstract

Cobalt selenide compounds are regarded as attractive anode materials for lithium-ion batteries. However, problems like as sluggish kinetics and volume change during repeated intercalation/deintercalation of Li+ severely limit their uses. In this work, a simple pyrolysis-selenization method is used to fabricate mixed-dimensional N-doped Co0.85Se@carbon nanotubes on carbon nanosheet (N-doped Co0.85Se@CNTs/C). The autocatalysis mechanism causes the curled carbon nanotubes to form on the carbon nanosheets. A small number of Co0.85Se nanoparticles are enclosed in the tops of carbon nanotubes, with the rest strewn on the surface of carbon nanosheets. Each component's synergistic contribution provides various ion/electron accessible paths as well as satisfying surface capacitive contributions, result in increased lithium storage performance. The N-doped Co0.85Se@CNTs/C composites exhibit excellent rate performance (596.6 mA h g−1 at 5 A g−1) and superb cycling performance (701.2 mA h g−1 after 600 cycles at 1 A g−1), as expected. This work shows that the construction of interface interaction may offer an alternative selection of anode materials based on rationally design for superior Lithium storage performance.