Three-dimensional cage-like structured VOF@CNT composite material: In situ one-step synthesis and high-performance as the anode for lithium-ion batteries

Abstract

Fabricating composites with three-dimensional (3D) nano-vanadium-based oxides and with carbon materials is one of the most effective ways to improve the performance of anode materials for lithium-ion batteries (LIBs). Herein, we firstly synthesized 3D V2O5 flowers (VOF) composed of interconnected ultrathin nanobelts through the surfactant-induced hydrothermal method, using vanadium pentoxide (V2O5) as vanadium source and carbon nanotubes as the carbon matrix. And then, the 3D VOF@CNT composite anode material was successfully prepared by in-situ bonding carbon nanotubes (CNT). Test results showed that the CNT can effectively inhibit the agglomeration of VOF nanoparticles, and thereby optimize the composite anode material's cycling stability and electrical conductivity. Meanwhile, as the carrier of lithium-ion (Li+), the VOF has a unique petal-like structure, which not only contributes to the Li+ diffusion and electron (e-) transport along the radial direction, but also provides sufficient space for the storage of Li+ and relieves the volume change of electrode during the cycle. Therefore, the composite electrode material still maintains at a high capacity of 417.7 mAh·g−1 after 200 cycles when the current density is 0.1 A·g−1. This work provides a method for preparing transition metal oxide electrode materials with great electrochemical performance and cycle stability.