title: Electrocatalytic activity of lithium polysulfides adsorbed into porous TiO2coated MWCNTs hybrid structure for lithium-sulfur batteries.
abstract: Lithium-sulfur batteries have attracted great attention because of their high energy density, environmental friendliness, natural abundance and intrinsically low cost of sulfur. However, their commercial applications are greatly hindered by rapid capacity decay due to poor conductivity of electrode, fast dissolution of the intermediate polysulfides into the electrolyte, and the volume expansion of sulfur. Herein, we report a novel composite MWCNTs@TiO2-S nanostructure by grafting TiO2onto the surface of MWCNTs, followed by incorporating sulfur into the composite. The inner MWCNTs improved the mechanical strength and conductivity of the electrode and the outer TiO2provided the adsorption sites to immobilize polysulfides due to bonding interaction between TiO2and polysulfides. The MWCNTs@TiO2-S composite with a mass ratio of 50% (MWCNTs in MWCNTs@TiO2) exhibited the highest electrochemistry performance among all compositing ratios of MWCNTs/TiO2. The performance improvement might be attributed to the downward shift of the apparent Fermi level to a more positive potential and electron rich space region at the interface of MWCNTs-TiO2that facilitates the reduction of lithium polysulfide at a higher potential. Such a novel hybrid structure can be applicable for electrode design in other energy storage applications.
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Xiulin
authors.initials: X
authors.lastname: He
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Huijie
authors.initials: H
authors.lastname: Hou
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Xiqing
authors.initials: X
authors.lastname: Yuan
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Long
authors.initials: L
authors.lastname: Huang
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Jingping
authors.initials: J
authors.lastname: Hu
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Bingchuan
authors.initials: B
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Electrical &Electronic Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Jia
authors.initials: J
authors.lastname: Xie
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Jiakuan
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Sha
authors.initials: S
authors.lastname: Liang
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P R China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wu