Cycling performance and failure behavior of lithium-ion battery Silicon-Carbon composite electrode

Abstract

Silicon-based anode materials have numerous advantages, including abundant reserves, high specific capacity, and environmental friendliness, which is an important direction for the development of anode materials in the future. However, the volume of silicon changes significantly during the processes of lithiation and de-lithiation, which limit its widespread use. In this study, silicon-carbon composites were prepared by using a high-temperature pyrolysis method. Among them, silicon was used as an active material, and phenolic resin served as the carbon source. Si@C showed better cycling stability and reversibility in constant current cycling tests compared silicon and graphite directly composites. Furthermore, according to the results of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), the addition of amorphous carbon can effectively reduce the electrode damage caused by volume expansion and the shrinkage of silicon materials, which has a positive effect on the stability of SEI. Additionally, the high conductivity of amorphous carbon improves the electrochemical kinetics of the battery during cycling, thereby enhancing the performance of silicon anodes.