title: Building 3D structures of vanadium pentoxide nanosheets and application as electrodes in supercapacitors.
abstract: Various two-dimensional (2D) materials have recently attracted great attention owing to their unique properties and wide application potential in electronics, catalysis, energy storage, and conversion. However, large-scale production of ultrathin sheets and functional nanosheets remains a scientific and engineering challenge. Here we demonstrate an efficient approach for large-scale production of V2O5 nanosheets having a thickness of 4 nm and utilization as building blocks for constructing 3D architectures via a freeze-drying process. The resulting highly flexible V2O5 structures possess a surface area of 133 m(2) g(-1), ultrathin walls, and multilevel pores. Such unique features are favorable for providing easy access of the electrolyte to the structure when they are used as a supercapacitor electrode, and they also provide a large electroactive surface that advantageous in energy storage applications. As a consequence, a high specific capacitance of 451 F g(-1) is achieved in a neutral aqueous Na2SO4 electrolyte as the 3D architectures are utilized for energy storage. Remarkably, the capacitance retention after 4000 cycles is more than 90%, and the energy density is up to 107 W·h·kg(-1) at a high power density of 9.4 kW kg(-1).
authors.affiliation: Department of Mechanical Engineering & Materials Science, Rice University , Houston, Texas 77005, United States.
authors.forename: Jixin
authors.initials: J
authors.lastname: Zhu
authors.forename: Liujun
authors.initials: L
authors.lastname: Cao
authors.forename: Yingsi
authors.initials: Y
authors.lastname: Wu
authors.forename: Yongji
authors.initials: Y
authors.lastname: Gong
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Harry E
authors.initials: HE
authors.lastname: Hoster
authors.forename: Yunhuai
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shengtao
authors.initials: S
authors.lastname: Zhang
authors.forename: Shubin
authors.initials: S
authors.lastname: Yang
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Yan
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan
authors.forename: Robert
authors.initials: R
authors.lastname: Vajtai
mesh_terms: D025802:Electric Capacitance; D004566:Electrodes; D004573:Electrolytes; D004867:Equipment Design; D049329:Nanostructures / Q000737:chemistry*; D017968:Vanadium Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004573:Electrolytes; D017968:Vanadium Compounds; D014867:Water; C066075:vanadium pentoxide