Controllable Preparation And Performance Characterization Of Silicon Nanoparticles By Using Of Spark Erosion And High-energy Ball Milling

With the rapid development of nanotechnology,silicon(Si),as an important semiconductor material,has attracted special attention in various fields because silicon nanoparticles(SiNPs)have special physical and chemical properties.At present,SiNPs have been used in microelectronics,coatings,biological medicine,new energy and other industries.For example,Doping SiNPs used in the preparation of local boron back field of PERC batteries can increase carrier concentration and the efficiency of the battery.Heavy doped SiNPs exhibit excellent rate performance as anode materials for lithium batteries.From the above,the increasing demand and application area extend more requirements for the properties of SiNPs,such as size distribution,doping characteristics and Micromorphology.But the existing methods of preparing SiNPs are characterized by high cost,strict equipment requirements and unrealization of the controllable preparation of size and doping characteristics.The paper firstly separated SiNPs with average diameter of 30~50 nm from the byproducts of the spark erosion machining monocrystalline silicon ingot and productivity of 1g/h.In addition,this method can realize the controllable preparation of doping characteristics by adopting different doped silicon ingot.In view of low productivity?low utilization of materials and unrealization of controllable preparation of particle size,the paper adopted high-energy ball milling(HEBM)after the transformation of bulk silicon material into powder by spark erosion to process SiNPs with mean size(D50)of 87.5 nm and productivity of 100g/h.Besides,this method can realize the controllable preparation of particle size by controlling the milling time.SEM?TEM ?XRD are used to study the microstructure of SiNPs.The results showed that SiNPs generated by spark erosion were spherical and had uniform shape.However,defects such as stacking faults and amorphous regions appeared inside the particles.As contrast,SiNPs generated by spark erosion combining with high-energy ball milling showed lamellar and obvious morphological difference.But the particles interior had better crystal structure.The paper characterized the electrochemical properties of two different SiNPs by assembling buckle battery whose electrode is made of two different SiNPs.The electrode made of SiNPs produced by spark erosion has better cycling performance due to more uniform and small particle size distribution,consistent micromorphology,rich stacking faults and even distributed amorphous regions in the particles.