Free-standing silicon nanorods on copper foil as anode for lithium-ion batteries
A Si thick film with a thickness of ca. 2?m was deposited on a copper substrate by electron cyclotron resonancechemical vapor deposition (ECRCVD) under a mixture of silane (SiH4) and argon (Ar) gases. The surface modification of the silicon anode was carried out by the metal-assisted chemical etching method. Observation by SEM showed that the silicon on the copper substrate had a nanorod structure as the result of the etching process. The electrochemical performance of the anode prepared using the free-standing Si nanorods showed a specific capacity of more than 2000mAh/g with 84% of the discharge capacity remaining ever after 25 cycles of charge and discharge, as compared with 35% of the discharge capacity remaining for the pristine Si thick film.
silicon nanorod metal-assisted chemical etching lithium-ion battery anode