title: A three-dimensional core-shell nanostructured composite of polypyrrole wrapped MnO(2)/reduced graphene oxide/carbon nanotube for high performance lithium ion batteries.
abstract: Manganese oxides are promising anode materials for their high-energy density. However, they suffer from poor rate capability and fast capacity fading. Herein, we construct a three-dimensional (3D) core-shell structured polypyrrole (PPy)/MnO2-reduced graphene oxide (rGO)-carbon nanotubes (CNTs) composite via a facile two-step method. In the structure, the CNTs can facilitate fast electron conduction and keep structural integrity. The flexible and conductive rGO nanosheets work as both a reactive material and a carrier for MnO2in-situ growth. The MnO2nanosheets well distributed on the rGO/CNTs scaffold favor the energy storage by way of fast Li+insertion and extraction. PPy nanoparticles (∼10nm) well wrapped on the MnO2nanosheets not only enable the interfacial stabilization, but also provide a buffer layer to accommodate the volume expansion. As a result, the as-prepared PPy/MnO2-rGO-CNTs composite exhibits high specific capacity, excellent cycling stability and good rate capability. A reversible specific capacity of 1748.1mAhg-1is achieved at the current density of 100mAg-1after 200 cycles. Even at a high current density of 1000mAg-1, the composite still exhibits 941.1mAhg-1after 1200 cycles. The design strategy of the composite can be extended to other high-capacity metal oxide material.
authors.affiliation: State Key Laboratory of Space Power-source Technology, Shanghai Institute of Space Power Sources, Shanghai 200245, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, S-41296 Gothenburg, Sweden. Electronic address: daixin@chalmers.se.
authors.forename: Daixin
authors.initials: D
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Space Power-source Technology, Shanghai Institute of Space Power Sources, Shanghai 200245, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Space Power-source Technology, Shanghai Institute of Space Power Sources, Shanghai 200245, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Space Power-source Technology, Shanghai Institute of Space Power Sources, Shanghai 200245, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Space Power-source Technology, Shanghai Institute of Space Power Sources, Shanghai 200245, China.
authors.forename: Haijuan
authors.initials: H
authors.lastname: Pei
authors.affiliation: State Key Laboratory of Space Power-source Technology, Shanghai Institute of Space Power Sources, Shanghai 200245, China. Electronic address: jyxie@mail.sim.ac.cn.
authors.forename: Jingying
authors.initials: J
authors.lastname: Xie
keywords: Carbon nanotubes; Lithium ion batteries; MnO(2); Polypyrrole; Reduced grapheneoxide