Thick electrode forming technology and properties of high capacity silicon-based anode materials

In order to alleviate the volume expansion and achieve the improvement electrochemical properties of silicon-based anode materials, a multiphase Si-MgO-G composite material was prepared using Mg, SiO and graphite as raw materials. The effect of different high energy ball milling process on the reaction degree of Mg and SiO were studied, and the application of thick electrode forming technology was discussed. The results showed that after high-energy ball milling for (1+5) h, Mg and SiO reacted in situ to produce Si-MgO product, and the reaction product was then mixed with graphite to prepare multiphase Si-MgO-G composite materials. The structure, morphology and phase constitution of the prepared silicon-based anode composite materials were characterized by XRD, SEM and TEM. It was found that the composite was composed of Si, MgO and graphite, and there was an interface coherent relationship of Si(220)//MgO(200). The electrochemical performances were analyzed by CV and EIS. The results indicated that the thickness, active material load and first area specific capacity of the SMG-6h thick electrode prepared by kneading and open milling process were about 7.4, 6.0 and 6.2 times of the thin electrode. This process demonstrates that simple, green thick electrode forming technique can increase the area specific capacity of lithium-ion batteries. © 2020, Editorial Office of FINE CHEMICALS. All right reserved.