Synthetic Strategy of Si@void@C Nanoparticles for High-Performance Lithium-Ion Battery Anodes

Silicon anode materials have the absolute predominance of high theoretical specific capacity, but its conductivity is low. What is more, the huge volume expansion (∼300%) of silicon during cycling causes rapid capacity fading. Herein, high-performance Si@void@C nanoparticles are synthesized by a unique ZnO template and mild strategy for the first time. Compared with the traditional synthesis method, a milder and environmentally friendly synthesis strategy provides a new feasible scheme for the large-scale commercialization of silicon anodes. The carbon layer blocks the silicon from the electrolyte and improves the conductivity of materials, and the yolk–void–shell structure accommodates the volume expansion of silicon during cycling. Si@void@C nanoparticles prepared with the ZnO template show excellent cycle and rate performances compared with the traditional synthetic strategy. After 500 cycles, the specific capacity of Si@void@C still maintains 934 mA h g–1 at 1 A g–1, and the average specific capacity is as high as 1125.4 mA h g–1 at a high current density of 4 A g–1. To sum up, the potential of Si@void@C anode for lithium-ion batteries cannot be underestimated.