title: Arrays of sealed silicon nanotubes as anodes for lithium ion batteries.
abstract: Silicon is a promising candidate for electrodes in lithium ion batteries due to its large theoretical energy density. Poor capacity retention, caused by pulverization of Si during cycling, frustrates its practical application. We have developed a nanostructured form of silicon, consisting of arrays of sealed, tubular geometries that is capable of accommodating large volume changes associated with lithiation in battery applications. Such electrodes exhibit high initial Coulombic efficiencies (i.e., >85%) and stable capacity-retention (>80% after 50 cycles), due to an unusual, underlying mechanics that is dominated by free surfaces. This physics is manifested by a strongly anisotropic expansion in which 400% volumetric increases are accomplished with only relatively small (<35%) changes in the axial dimension. These experimental results and associated theoretical mechanics models demonstrate the extent to which nanoscale engineering of electrode geometry can be used to advantage in the design of rechargeable batteries with highly reversible capacity and long-term cycle stability.
authors.affiliation: Division of Materials Science Engineering, Hanyang University, Seoul, Korea.
authors.forename: Taeseup
authors.initials: T
authors.lastname: Song
authors.forename: Jianliang
authors.initials: J
authors.lastname: Xia
authors.forename: Jin-Hyon
authors.initials: JH
authors.lastname: Lee
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Lee
authors.forename: Moon-Seok
authors.initials: MS
authors.lastname: Kwon
authors.forename: Jae-Man
authors.initials: JM
authors.lastname: Choi
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Seok Kwang
authors.initials: SK
authors.lastname: Doo
authors.forename: Hyuk
authors.initials: H
authors.lastname: Chang
authors.forename: Won Il
authors.initials: WI
authors.lastname: Park
authors.forename: Dong Sik
authors.initials: DS
authors.lastname: Zang
authors.forename: Hansu
authors.initials: H
authors.lastname: Kim
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Huang
authors.forename: Keh-Chih
authors.initials: KC
authors.lastname: Hwang
authors.forename: John A
authors.initials: JA
authors.lastname: Rogers
authors.forename: Ungyu
authors.initials: U
authors.lastname: Paik
mesh_terms: D003460:Crystallization / Q000379:methods; D011211:Electric Power Supplies; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008094:Lithium / Q000737:chemistry*; D008422:Materials Testing; D036103:Nanotechnology / Q000295:instrumentation*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*
chemical_list: D008094:Lithium; D012825:Silicon