NH_4V_3O_8/carbon nanotubes composite cathode material with high capacity and good rate capability

摘要

NH_4V_3O_8/carbon nanotubes (CNTs) composites are synthesized by one-step hydrothermal method. All the samples show the flake-like morphology with the width of up to 5 |xm and thickness of 500 nm and the CNTs are clearly observed on the surface of modified NH_4V_3O_8 It is found that incorporation of 0.5 wt% CNTs into NH_4V_3O_8 could greatly improve its discharge capacity and cycling stability. It delivers a maximum discharge capacity of 358.7 mAhg~(-1) at 30mAg~(-1), 55mAhg~(-1) larger than that of the pristine one. At 150 mA g~(-1), the composite shows 226.2 mAh g~(-1) discharge capacity with excellent capacity retention of 97% after 100 cycles. The much improved electrochemical performance of NH_4V_3O_8 is attributed to incorporation of CNTs, which facilitates the interface charge transfer and Li* diffusion.