Mechanically Robust Si Nanorod Arrays on Cu/Ti Bilayer Film Coated Si Substrate for High Performance Lithium-Ion Battery Anodes

The deformation behavior and mechanical properties of a tilted Si nanorod array structure on Cu/Ti bilayer film coated Si substrate were studied for the first time by coupled atomic force microscopy and nanoindentation techniques. The individual Si nanorods fabricated by an oblique angle deposition technique are composed of many fine Si nanofibers with the diameter ranging from 10 to 50 nm. They are not brittle, but ductile. The ductile metallic Cu/Ti bilayer film roots contribute remarkably to the mechanical robustness of the Si nanorods. The toughening mechanism of such Si-based nanoanodes has been elucidated by experimental mechanics studies