Coralloid-like Nanostructured c-nSi/SiO_x@C_y Anodes for High Performance Lithium Ion Battery

Balancing the size of the primary Si unit and void space is considered to be an effective approach for developing high performance silicon-based anode materials and is vital to create a lithium ion battery with high energy density. We herein have demonstrated the facile fabrication of coralloid-like nanostructured silicon composites (c-nSi/SiO_x@Cy) via sulfuric acid etching the Al₆₀Si₄₀ alloy, followed by a surface growth carbon layer approach. The HRTEM images of pristine and cycled c-nSi/SiO_x@Cy show that abundant nanoscale internal pores and the continuous conductive carbon layer effectively avoid the pulverization and agglomeration of Si units during multiple cycles. It is interesting that the c-nSi/SiO_x@C_4.0 anode exhibits a high initial Coulombic efficiency of 85.53%, and typical specific capacity of over 850 mAh g^-1 after deep 500 cycles at a current density of 1 A g^-1. This work offers a facile strategy to create silicon-based anodes consisting of highly dispersed primary nano-Si units.