Multiwalled carbon nanotubes-V2O5 integrated composite with nanosized architecture as a cathode material for high performance lithium ion batteries

Multiwalled carbon nanotubes (MWCNTs)-V2O5 integrated composite with nanosized architecture has been synthesized through hydrothermal treatment combined with a post-sintering process. During the hydrothermal reaction, protonated hexadecylamine (C16H33NH3+) acts as an intermediator, which links the negatively charged vanadium oxide layer with the mixed-acid pretreated MWCNTs by weak electrostatic forces to form a three-phase hybrid (MWCNTs-C-16-V-Ox). MWCNT-V2O5 composite and V2O5 nanoparticles can be obtained by sintering MWCNTs-C-16-V-Ox at 400 and 550 degrees C in air, respectively. Among them, MWCNTs-V2O5 possesses better electrochemical performance as a cathode material for lithium ion batteries (LIBs). The unique porous nanoarchitecture of MWCNTs-V2O5 provides a large specific surface area and a good conductive network, which facilitates fast lithium ion diffusion and electron transfer. Additionally, the uniformly dispersed MWCNTs conducting network also behaves as an effective buffer which can relax the strain generated during charge-discharge cycles. Electrochemical tests reveal that MWCNTs-V2O5 could deliver a superior specific capacity (402 mA h g(-1) during initial discharge at a current density of 100 mA g(-1) between 1.5 and 4 V versus Li/Li+), good cycling stability (222 mA h g (1) after 50 cycles) and high rate capability (194 mA h g (1) at a current density of 800 mA g (1)).