Ultrafast hetero-assembly of monolithic interwoven V_2O_5 nanobelts/carbon nanotubes architectures for high-energy alkali-ion batteries

摘要

Monolithic interwoven composite of V2O5 nanobelts and carbon nanotubes (designated as VNT5 subset of CNTs-40) is prepared via one-pot hydrothermal synthesis and subsequent vacuum filtration. The strong synergistic effect between versatile CNTs and in situ produced V2O5 nanobelts in hydrothermal process leads to the formation of 3D interwoven mesh intermediate with relatively loose and well-reticulated channels which facilitate mass transfer in ultrafast hetero-assembly (similar to 30s) of film-like monolithic VNTs subset of CNTs-40 composite during vacuum filtration. The interconnected CNTs network and interstitial porous channels in the monolithic VNT5 subset of CNTs-40 composite not only improve charge transport during the redox reactions of the active materials, but also serve as a robust and flexible buffer to accommodate the volume change during repetitive ion insertion/extraction. In the evaluation of binder-free cathodes in alkali-ion batteries, the monolithic VNT5 subset of CNTs-40 composite exhibits outstanding alkali-ion storage properties such as high initial capacity (215.2/295.8 mAhg(-1) for SIBs/LIBs at a current density of 200 mAg(-1)), high-rate capability (137.8/156.2 mAhg(-1) for SIBs/LIBs at a current density of 800/2000 mAg(-1)), and superior cycling stability (167/223.5 mAhg(-1) for SIBs/LIBs at a current density of 200 mAg(-1) after 200 cycles). The monolithic VNTs subset of CNTs-40 composite has large potential in high-performance alkali-ion batteries.