Structure Design and Performance of the Graphite/Silicon/Carbon Nanotubes/Carbon (GSCC) Composite as the Anode of a Li-Ion Battery

Silicon (Si) or Si-based compounds have been paid much attention in the field of lithium-ion battery anodes on account of desirable theoretical capacity, moderate working voltage, abundant resources, and bing nontoxic. However, some disadvantages, including inferior electrical conductivity and enormous volume change in the process of lithiation/delithiation, hinder their widespread application in commercial lithium-ion batteries. To solve the above problems, we designed and prepared the graphite/silicon/carbon nanotubes/carbon (GSCC) composites with hierarchical structure. Herein, the graphite can absorb the bulk expansion stress of the Si particles. The carbon layer carbonized by pitch can further mitigate the volume change and physically separate Si and electrolyte, and an admirable conductive network can be provided by the carbon nanotube. As a consequence, the as-prepared GSCC electrode possesses a capacity of 1100.6 mAh g–1 at 0.2 A g–1 and high initial coulomb efficiency (ICE) of 78% and has a good capacity retention of 73%. Therefore, the combinational design of the graphite/silicon/carbon nanotubes/carbon for the preparation of a silicon-based anode material is a meaningful exploration for large-scale production and commercial application in lithium ion batteries.