title: In situ observation of the electrochemical lithiation of a single SnO₂ nanowire electrode.
abstract: We report the creation of a nanoscale electrochemical device inside a transmission electron microscope--consisting of a single tin dioxide (SnO(2)) nanowire anode, an ionic liquid electrolyte, and a bulk lithium cobalt dioxide (LiCoO(2)) cathode--and the in situ observation of the lithiation of the SnO(2) nanowire during electrochemical charging. Upon charging, a reaction front propagated progressively along the nanowire, causing the nanowire to swell, elongate, and spiral. The reaction front is a "Medusa zone" containing a high density of mobile dislocations, which are continuously nucleated and absorbed at the moving front. This dislocation cloud indicates large in-plane misfit stresses and is a structural precursor to electrochemically driven solid-state amorphization. Because lithiation-induced volume expansion, plasticity, and pulverization of electrode materials are the major mechanical effects that plague the performance and lifetime of high-capacity anodes in lithium-ion batteries, our observations provide important mechanistic insight for the design of advanced batteries.
authors.affiliation: Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM 87185, USA. jhuang@sandia.gov
authors.forename: Jian Yu
authors.initials: JY
authors.lastname: Huang
authors.forename: Li
authors.initials: L
authors.lastname: Zhong
authors.forename: Chong Min
authors.initials: CM
authors.lastname: Wang
authors.forename: John P
authors.initials: JP
authors.lastname: Sullivan
authors.forename: Wu
authors.initials: W
authors.lastname: Xu
authors.forename: Li Qiang
authors.initials: LQ
authors.lastname: Zhang
authors.forename: Scott X
authors.initials: SX
authors.lastname: Mao
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Hudak
authors.forename: Xiao Hua
authors.initials: XH
authors.lastname: Liu
authors.forename: Arunkumar
authors.initials: A
authors.lastname: Subramanian
authors.forename: Hongyou
authors.initials: H
authors.lastname: Fan
authors.forename: Liang
authors.initials: L
authors.lastname: Qi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kushima
authors.forename: Ju
authors.initials: J
authors.lastname: Li