Scalable Fabrication of Silicon‐Graphite Microsphere by Mechanical Processing for Lithium‐Ion Battery Anode with Large Capacity and High Cycling Stability

Abstract

AbstractIn order to combine the high stability of graphite and the large theoretical capacity of silicon, silicon‐graphite composites attract tremendous attentions. However, the cycling stability is still a bottleneck hindering their commercialization due to the large volume expansion and poor interface compatibility. In this study, the bead grinding method is used to break micro‐sized silicon and graphite particles by strong shear force simultaneously, inducing the solid‐solid interface reaction between fresh silicon nanoparticles and graphite nanosheets. Subsequently, an evaporation induced self‐assembly happens in spray drying process, allow for scalable synthesis of Si‐graphite microsphere. The silicon‐graphite microsphere (Si−G microsphere) delivers an excellent cycling performance, with a reversible capacity of 1895 mAh g−1 at a current density of 0.5 A g−1 over 500 cycles and a capacity retention of 99.8 %. Moreover, the pouch‐type full battery of Si−G microsphere/graphite||LiNi0.5Co0.2Mn0.3O2 exhibits remarkable cycling stability with the capacity retention of 79.3 % after 800 cycles. The manufacture process using commercial raw materials and simple mechanical strategy demonstrates great potential for the low‐cost and scaled synthesis of high‐performance silicon‐graphite anodes.