title: Coaxial carbon/metal oxide/aligned carbon nanotube arrays as high-performance anodes for lithium ion batteries.
abstract: Coaxial carbon/metal oxide/aligned carbon nanotube (ACNT) arrays over stainless-steel foil are reported as high-performance binder-free anodes for lithium ion batteries. The coaxial arrays were prepared by growth of ACNTs over stainless-steel foil followed by coating with metal oxide and carbon. The carbon/manganese oxide/ACNT arrays can deliver an initial capacity of 738 mAh g(-1) with 99.9 % capacity retention up to 100 cycles and a capacity of 374 mAh g(-1) at a high current density of 6000 mA g(-1). The external carbon layer was recognized as a key component for high performance, and the mechanism of performance enhancement was investigated by electrochemical impedance spectroscopy, electron microscopy, and X-ray diffraction analysis. The layer increases rate capability by enhancing electrical conductivity and maintaining a low mass-transfer resistance and also improves cyclic stability by avoiding aggregation of metal-oxide particles and stabilizing the solid electrolyte interface. The resultant principle of rational electrode design was applied to an iron oxide-based system, and similar improvements were found. These coaxial nanotube arrays present a promising strategy for the rational design of high-performance binder-free anodes for lithium ion batteries.
authors.affiliation: Department of Chemical Engineering, Norwegian University of Science and Technology, Sem Saelands vei 4, 7491 Trondheim (Norway), Fax: (+47)73595047 http://www.nt.ntnu.no/users/chen/index.htm.
authors.forename: Fengliu
authors.initials: F
authors.lastname: Lou
authors.forename: Haitao
authors.initials: H
authors.lastname: Zhou
authors.forename: Trung Dung
authors.initials: TD
authors.lastname: Tran
authors.forename: Marthe Emelie
authors.initials: ME
authors.lastname: Melandsø Buan
authors.forename: Fride
authors.initials: F
authors.lastname: Vullum-Bruer
authors.forename: Magnus
authors.initials: M
authors.lastname: Rønning
authors.forename: John Charles
authors.initials: JC
authors.lastname: Walmsley
authors.forename: De
authors.initials: D
authors.lastname: Chen
mesh_terms: D004553:Electric Conductivity; D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D004867:Equipment Design; D008094:Lithium / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D013499:Surface Properties; D013818:Thermogravimetry
chemical_list: D017895:Manganese Compounds; D037742:Nanotubes, Carbon; D010087:Oxides; C027424:manganese oxide; D008094:Lithium
keywords: carbon; electrochemistry; electron microscopy; nanotubes; x-ray diffraction