title: Anomalous Stagewise Lithiation of Gold-Coated Silicon Nanowires: A Combined In Situ Characterization and First-Principles Study.
abstract: Through a combined density functional theory and in situ scanning electron microscopy study, the effects of presence of gold (Au) spreading on the lithiation process of silicon nanowire (SiNW) were systematically examined. Different from a pristine SiNW, an Au-coated SiNW (Au-SiNW) is lithiated in three distinct stages; Li atoms are found to be incorporated preferentially in the Au shell, whereas the thin AuSi interface layer may serve as a facile diffusion path along the nanowire axial direction, followed by the prompt lithiation of the Si core in the radial direction. The underlying mechanism of the intriguing stagewise lithiation behavior is explained through our theoretical analysis, which appears well-aligned with the experimental evidence.
authors.forename: Chia-Yun
authors.initials: CY
authors.lastname: Chou
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Seo
authors.forename: Yu-Hao
authors.initials: YH
authors.lastname: Tsai
authors.forename: Jae-Pyoung
authors.initials: JP
authors.lastname: Ahn
authors.forename: Eunsu
authors.initials: E
authors.lastname: Paek
authors.affiliation: ∥Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
authors.forename: Mann-Ho
authors.initials: MH
authors.lastname: Cho
authors.forename: In-Suk
authors.initials: IS
authors.lastname: Choi
authors.forename: Gyeong S
authors.initials: GS
authors.lastname: Hwang
keywords: density functional theory calculation; gold-coated silicon nanowire; in situ characterization; lithium ion battery; stagewise lithiation