A high-performance silicon/carbon composite as anode material for lithium ion batteries
Yangzhi Bai, Xinlong Cao, Zhanyuan Tian, Shifeng Yang, Guolin Cao
Abstract
Abstract To overcome the existing rapid capacity decay, low conductivity and the expands and contracts in volume of Si/C composite anodes in lithium ion batteries, we have developed a silicon/carbon composite by spray drying and twice organic carbon source cladding process. The samples are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectrometer, thermogravimetric analysis and x-ray photoelectron spectra (XPS). The electrochemical performance are analyzed by half-cell and full-cell experiments. The results show that the silicon/carbon composite is core–shell structure with the silicon embedded graphite as core and organic carbon layers as the shell, the particle size range from 8 μ m to 24 μ m. The first reversible capacity and initial coulombic efficiency of the silicon/carbon composite are 936.4 mAh g −1 and 88.6% in half-cell. The silicon/carbon composite exhibits a high capacity retention up to 80% after 680 cycles in full-cell, indicating an excellent cycling stability. The structure is beneficial to control volume expansion, improve conductivity and electrochemical performance.