title: Germanium Silicon Alloy Anode Material Capable of Tunable Overpotential by Nanoscale Si Segregation.
abstract: We developed the novel electrode that enables fine control of overpotential by exploiting surface segregation that is the enrichment of one component at the surface of binary alloy. To realize this approach, we controlled the proportion of Si with low Li diffusivity at the surface by annealing the SiGe nanowire in H2 environment at various temperatures. The resulting SiGe nanowires annealed at 850 °C exhibited high reversible capacity (>1031 mA·h·g(-1)), and long cycle life (400 cycles) with high capacity retention (89.0%) at 0.2 C. This superior battery performance is attributed to the remaining unlithiated part acting as support frame to prevent pulverization of anode material, which results from the fine-tuning of overpotential by controlling the degree of Si segregation.
authors.affiliation: †Center for Artificial Low Dimensional Electronic System, Institute for Basic Science (IBS), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.|‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.
authors.forename: Hyungki
authors.initials: H
authors.lastname: Kim
authors.affiliation: §Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798 Korea.
authors.forename: Yoonkook
authors.initials: Y
authors.lastname: Son
authors.affiliation: †Center for Artificial Low Dimensional Electronic System, Institute for Basic Science (IBS), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.|‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.
authors.forename: Chibeom
authors.initials: C
authors.lastname: Park
authors.affiliation: §Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798 Korea.
authors.forename: Min-Joon
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: †Center for Artificial Low Dimensional Electronic System, Institute for Basic Science (IBS), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.|‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.
authors.forename: Misun
authors.initials: M
authors.lastname: Hong
authors.affiliation: †Center for Artificial Low Dimensional Electronic System, Institute for Basic Science (IBS), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.|‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.
authors.forename: Jungah
authors.initials: J
authors.lastname: Kim
authors.affiliation: †Center for Artificial Low Dimensional Electronic System, Institute for Basic Science (IBS), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.|‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.
authors.forename: Minkyung
authors.initials: M
authors.lastname: Lee
authors.affiliation: §Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798 Korea.
authors.forename: Jaephil
authors.initials: J
authors.lastname: Cho
authors.affiliation: †Center for Artificial Low Dimensional Electronic System, Institute for Basic Science (IBS), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.|‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 790-784 Korea.
authors.forename: Hee Cheul
authors.initials: HC
authors.lastname: Choi
keywords: GeSi nanowire; Surface segregation; cycling stability; lithium ion battery anode; overpotential