title: In situ atomic-scale imaging of electrochemical lithiation in silicon.
abstract: In lithium-ion batteries, the electrochemical reaction between the electrodes and lithium is a critical process that controls the capacity, cyclability and reliability of the battery. Despite intensive study, the atomistic mechanism of the electrochemical reactions occurring in these solid-state electrodes remains unclear. Here, we show that in situ transmission electron microscopy can be used to study the dynamic lithiation process of single-crystal silicon with atomic resolution. We observe a sharp interface (~1 nm thick) between the crystalline silicon and an amorphous Li(x)Si alloy. The lithiation kinetics are controlled by the migration of the interface, which occurs through a ledge mechanism involving the lateral movement of ledges on the close-packed {111} atomic planes. Such ledge flow processes produce the amorphous Li(x)Si alloy through layer-by-layer peeling of the {111} atomic facets, resulting in the orientation-dependent mobility of the interfaces.
authors.affiliation: Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA. lxhua99@gmail.com
authors.forename: Xiao Hua
authors.initials: XH
authors.lastname: Liu
authors.forename: Jiang Wei
authors.initials: JW
authors.lastname: Wang
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.forename: Feifei
authors.initials: F
authors.lastname: Fan
authors.forename: Xu
authors.initials: X
authors.lastname: Huang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Sergiy
authors.initials: S
authors.lastname: Krylyuk
authors.forename: Jinkyoung
authors.initials: J
authors.lastname: Yoo
authors.forename: Shadi A
authors.initials: SA
authors.lastname: Dayeh
authors.forename: Albert V
authors.initials: AV
authors.lastname: Davydov
authors.forename: Scott X
authors.initials: SX
authors.lastname: Mao
authors.forename: S Tom
authors.initials: ST
authors.lastname: Picraux
authors.forename: Sulin
authors.initials: S
authors.lastname: Zhang
authors.forename: Ju
authors.initials: J
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Zhu
authors.forename: Jian Yu
authors.initials: JY
authors.lastname: Huang
mesh_terms: D003460:Crystallization; D011211:Electric Power Supplies; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure*; D012825:Silicon / Q000737:chemistry*
chemical_list: D008094:Lithium; D012825:Silicon