Microano-structure Co_3O_4 as high capacity anode materials for lithium-ion batteries and the effect of the void volume on electrochemical performance

摘要

Two kinds of Co_3O_4 samples with microano-structure as high capacity anode materials for Lithium-ion Batteries are synthesized by a facile method. The structure, composition and surface morphology are analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), respectively. The XRD data indicates that the two Co_3O_4 materials are crystalline, single-phase without any impurity phase; the size of spheres and cubes are estimated to be 2 urn and the nanoparticles are around 100 nm. The cyclic voltammetry and discharge/ charge measurements are carried out to detect the electrochemical properties. The results demonstrate that the two Co_3O_4 electrodes with microano-structure exhibit low initial irreversible capacity and superior cycling performance. The two Co_3O_4 materials with microano-structure are confirmed to combine the advantages of the micro-materials and nano-materials for LIBs. Moreover, the Co_3O_4 spheres (s-Co_3O_4) exhibit more superior cycling performance than that of Co_3O_4 cubes (c-Co_3O_4) due to the larger void volume in spheres than that in cubes structure.