title: Anisotropic swelling and fracture of silicon nanowires during lithiation.
abstract: We report direct observation of an unexpected anisotropic swelling of Si nanowires during lithiation against either a solid electrolyte with a lithium counter-electrode or a liquid electrolyte with a LiCoO(2) counter-electrode. Such anisotropic expansion is attributed to the interfacial processes of accommodating large volumetric strains at the lithiation reaction front that depend sensitively on the crystallographic orientation. This anisotropic swelling results in lithiated Si nanowires with a remarkable dumbbell-shaped cross section, which develops due to plastic flow and an ensuing necking instability that is induced by the tensile hoop stress buildup in the lithiated shell. The plasticity-driven morphological instabilities often lead to fracture in lithiated nanowires, now captured in video. These results provide important insight into the battery degradation mechanisms.
authors.affiliation: Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States.
authors.forename: Xiao Hua
authors.initials: XH
authors.lastname: Liu
authors.forename: He
authors.initials: H
authors.lastname: Zheng
authors.forename: Li
authors.initials: L
authors.lastname: Zhong
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.forename: Khim
authors.initials: K
authors.lastname: Karki
authors.forename: Li Qiang
authors.initials: LQ
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kushima
authors.forename: Wen Tao
authors.initials: WT
authors.lastname: Liang
authors.forename: Jiang Wei
authors.initials: JW
authors.lastname: Wang
authors.forename: Jeong-Hyun
authors.initials: JH
authors.lastname: Cho
authors.forename: Eric
authors.initials: E
authors.lastname: Epstein
authors.forename: Shadi A
authors.initials: SA
authors.lastname: Dayeh
authors.forename: S Tom
authors.initials: ST
authors.lastname: Picraux
authors.forename: Ting
authors.initials: T
authors.lastname: Zhu
authors.forename: Ju
authors.initials: J
authors.lastname: Li
authors.forename: John P
authors.initials: JP
authors.lastname: Sullivan
authors.forename: John
authors.initials: J
authors.lastname: Cumings
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Wang
authors.forename: Scott X
authors.initials: SX
authors.lastname: Mao
authors.forename: Zhi Zhen
authors.initials: ZZ
authors.lastname: Ye
authors.forename: Sulin
authors.initials: S
authors.lastname: Zhang
authors.forename: Jian Yu
authors.initials: JY
authors.lastname: Huang