title: Ge/C nanowires as high-capacity and long-life anode materials for Li-ion batteries.
abstract: Germanium-based materials (Ge and GeOx) have recently demonstrated excellent lithium-ion storage ability and are being considered as the most promising candidates to substitute commercial carbon-based anodes of lithium-ion batteries. Nevertheless, practical implementation of Ge-based materials to lithium-ion batteries is greatly hampered by the poor cyclability that resulted from the huge volume variation during lithiation/delithiation processes. Herein, uniform carbon-encapsulated Ge and GeOx nanowires were synthesized by a one-step controlled pyrolysis of organic-inorganic hybrid GeOx/ethylenediamine (GeOx/EDA) nanowires in H2/Ar and Ar atmospheres, respectively. The as-obtained Ge/C and GeOx/C nanowires possess well-defined 0D-in-1D morphology and homogeneous carbon encapsulation, which exhibit excellent Li storage properties including high specific capacities (approximate 1200 and 1000 mA h g(-1) at 0.2C for Ge/C and GeOx/C, respectively). The Ge/C nanowires, in particular, demonstrate superior rate capability with excellent capacity retention and stability (producing high stable discharge capacities of about 770 mA h g(-1) after 500 cycles at 10C), making them promising candidates for future electrodes for high-power Li-ion batteries. The improved electrochemical performance arises from synergistic effects of 0D-in-1D morphology and uniform carbon coating, which could effectively accommodate the huge volume change of Ge/GeOx during cycling and maintain perfect electrical conductivity throughout the electrode.
authors.affiliation: CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China , Hefei 230026, Anhui, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Kepeng
authors.initials: K
authors.lastname: Song
authors.forename: Changbao
authors.initials: C
authors.lastname: Zhu
authors.forename: Chia-Chin
authors.initials: CC
authors.lastname: Chen
authors.forename: Peter A
authors.initials: PA
authors.lastname: van Aken
authors.forename: Joachim
authors.initials: J
authors.lastname: Maier
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu