Abstract
To effectively address fundamental problems in using transition metal oxides as high-performance anode materials for lithium ion batteries (LIBs), we prepare Co3O4 QDs@SWCNT heterostructures composed of well-dispersed ultrafine cobalt oxide (Co3O4) encapsulated within flexible sheet-like single-walled carbon nanotubes (SWCNTs) matrix for the first time, through a facile and controllable method via evaporation-induced self-assembly (EISA) of single-walled carbon nanotubides (SWCNTDs). By varying the loading amount of Co3O4 content in the heterostructure, the optimized sample containing Co3O4 QDs as high as 83.3 wt% exhibits a very high specific capacity of 1198 mAh g-1 after 50 cycles at a specific current of 100 mA g-1 and a superior rate capability with high capacities of 1080, 944, 833, 648 and 423 mAh g-1 at specific currents of 100, 500, 1000, 2000 and 5000 mA g-1, respectively. When the specific current returns to 100 mA g-1, the optimized Co3O4 QDs@SWCNT heterostructure still delivers a very high capacity of ~1300 mAh g-1 after 40 extended cycles, demonstrating outstanding electrochemical reversibility. Moreover, the optimal Co3O4 QDs@SWCNT heterostructure demonstrates superior prolonged cycling stability for over 200 and 600 cycles at extremely high specific currents of 1000 and 2000 mA g-1, respectively. Such superior electrochemical performances are ascribed to the synergic effect of ultrafine Co3O4 nanoparticles and SWCNTs in the heterostructure, in which the robust SWCNTs not only offer excellent strain accommodation of the encapsulated Co3O4upon long-term cycling, but also significantly enhance overall electrical conductivity and mechanical stability of the electrodes. The facile and effective strategy in this work can be extended to design various nanoparticles@SWCNTs heterostructures for potential applications in LIBs, supercapacitors, catalysts, sensors and other fields. Keywords: Co3O4 QDs; Sheet-like SWCNTs; Evaporation-induced self-assembly; Rate capability; Prolonged cycling stability; Lithium ion battery
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
