title: Novel germanium/polypyrrole composite for high power lithium-ion batteries.
abstract: Nano-Germanium/polypyrrole composite has been synthesized by chemical reduction method in aqueous solution. The Ge nanoparticles were directly coated on the surface of the polypyrrole. The morphology and structural properties of samples were determined by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Thermogravimetric analysis was carried out to determine the polypyrrole content. The electrochemical properties of the samples have been investigated and their suitability as anode materials for the lithium-ion battery was examined. The discharge capacity of the Ge nanoparticles calculated in the Ge-polypyrrole composite is 1014 mAh g(-1) after 50 cycles at 0.2 C rate, which is much higher than that of pristine germanium (439 mAh g(-1)). The composite also demonstrates high specific discharge capacities at different current rates (1318, 1032, 661, and 460 mAh g(-1) at 0.5, 1.0, 2.0, and 4.0 C, respectively). The superior electrochemical performance of Ge-polypyrrole composite could be attributed to the polypyrrole core, which provides an efficient transport pathway for electrons. SEM images of the electrodes have demonstrated that polypyrrole can also act as a conductive binder and alleviate the pulverization of electrode caused by the huge volume changes of the nanosized germanium particles during Li(+) intercalation/de-intercalation.
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Xuanwen
authors.initials: X
authors.lastname: Gao
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Luo
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhong
authors.affiliation: School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Wexler
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Shu-Lei
authors.initials: SL
authors.lastname: Chou
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Hua-Kun
authors.initials: HK
authors.lastname: Liu
authors.affiliation: Centre for Green Products and Processing Technologies, Guangzhou HKUST Fok Ying Tung Research Institute, Guangzhou, China.
authors.forename: Zhicong
authors.initials: Z
authors.lastname: Shi
authors.affiliation: 1] Centre for Green Products and Processing Technologies, Guangzhou HKUST Fok Ying Tung Research Institute, Guangzhou, China [2] Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Chen
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba-city Ibaraki 305-0047, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ozawa
authors.affiliation: Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Jia-Zhao
authors.initials: JZ
authors.lastname: Wang