Micro/nano-structure Co3O4 as high capacity anode materials for lithium-ion batteries and the effect of the void volume on electrochemical performance

Two kinds of Co3O4 samples with micro/nano-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 Co3O4 materials are crystalline, single-phase without any impurity phase; the size of spheres and cubes are estimated to be 2 μm 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 Co3O4 electrodes with micro/nano-structure exhibit low initial irreversible capacity and superior cycling performance. The two Co3O4 materials with micro/nano-structure are confirmed to combine the advantages of the micro-materials and nano-materials for LIBs. Moreover, the Co3O4 spheres (s-Co3O4) exhibit more superior cycling performance than that of Co3O4 cubes (c-Co3O4) due to the larger void volume in spheres than that in cubes structure.