title: High-energy lithium-ion hybrid supercapacitors composed of hierarchical urchin-like WO3/C anodes and MOF-derived polyhedral hollow carbon cathodes.
abstract: A lithium-ion hybrid supercapacitor (Li-HSC) comprising a Li-ion battery type anode and an electrochemical double layer capacitance (EDLC) type cathode has attracted much interest because it accomplishes a large energy density without compromising the power density. In this work, hierarchical carbon coated WO3(WO3/C) with a unique mesoporous structure and metal-organic framework derived nitrogen-doped carbon hollow polyhedra (MOF-NC) are prepared and adopted as the anode and the cathode for Li-HSCs. The hierarchical mesoporous WO3/C microspheres assembled by radially oriented WO3/C nanorods along the (001) plane enable effective Li+insertion, thus exhibit high capacity, excellent rate performance and a long cycling life due to their high Li+conductivity, electronic conductivity and structural robustness. The WO3/C structure shows a reversible specific capacity of 508 mA h g-1at a 0.1 C rate (1 C = 696 mA h g-1) after 160 discharging-charging cycles with excellent rate capability. The MOF-NC achieved the specific capacity of 269.9 F g-1at a current density of 0.2 A g-1. At a high current density of 6 A g-1, 92.4% of the initial capacity could be retained after 2000 discharging-charging cycles, suggesting excellent cycle stability. The Li-HSC comprising a WO3/C anode and a MOF-NC cathode boasts a large energy density of 159.97 W h kg-1at a power density of 173.6 W kg-1and 88.3% of the capacity is retained at a current density of 5 A g-1after 3000 charging-discharging cycles, which are better than those previously reported for Li-HSCs. The high energy and power densities of the Li-HSCs of WO3/C//MOF-NC render large potential in energy storage.
authors.affiliation: Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China. kfhuo@hust.edu.cn.
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.affiliation: Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China. kfhuo@hust.edu.cn.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China. kfhuo@hust.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China. kfhuo@hust.edu.cn.
authors.forename: Qifa
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China. kfhuo@hust.edu.cn and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Li
authors.affiliation: The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Gao
authors.affiliation: The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Xuming
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China. kfhuo@hust.edu.cn.
authors.forename: Kaifu
authors.initials: K
authors.lastname: Huo
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Paul K
authors.initials: PK
authors.lastname: Chu