title: Mesoporous Hybrids of Reduced Graphene Oxide and Vanadium Pentoxide for Enhanced Performance in Lithium-Ion Batteries and Electrochemical Capacitors.
abstract: Mesoporous hybrids of V2O5 nanoparticles anchored on reduced graphene oxide (rGO) have been synthesized by slow hydrolysis of vanadium oxytriisopropoxide using a two-step solvothermal method followed by vacuum annealing. The hybrid material possesses a hierarchical structure with 20-30 nm V2O5 nanoparticles uniformly grown on rGO nanosheets, leading to a high surface area with mesoscale porosity. Such hybrid materials present significantly improved electronic conductivity and fast electrolyte ion diffusion, which synergistically enhance the electrical energy storage performance. Symmetrical electrochemical capacitors with two rGO-V2O5 hybrid electrodes show excellent cycling stability, good rate capability, and a high specific capacitance up to ∼466 F g(-1) (regarding the total mass of V2O5) in a neutral aqueous electrolyte (1.0 M Na2SO4). When used as the cathode in lithium-ion batteries, the rGO-V2O5 hybrid demonstrates excellent cycling stability and power capability, able to deliver a specific capacity of 295, 220, and 132 mAh g(-1) (regarding the mass of V2O5) at a rate of C/9, 1C, and 10C, respectively. The value at C/9 rate matches the full theoretical capacity of V2O5 for reversible 2 Li(+) insertion/extraction between 4.0 and 2.0 V (vs Li/Li(+)). It retains ∼83% of the discharge capacity after 150 cycles at 1C rate, with only 0.12% decrease per cycle. The enhanced performance in electrical energy storage reveals the effectiveness of rGO as the structure template and more conductive electron pathway in the hybrid material to overcome the intrinsic limits of single-phase V2O5 materials.
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Gaind P
authors.initials: GP
authors.lastname: Pandey
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Emery
authors.initials: E
authors.lastname: Brown
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Grain Science and Industry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Grain Science and Industry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Xiuzhi Susan
authors.initials: XS
authors.lastname: Sun
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.|The Institute of Biomaterial, College of Materials and Energy, South China Agricultural University , Guangzhou, Guangdong 510642, China.
authors.forename: Yueping
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Chemistry, Kansas State University , Manhattan, Kansas 66506, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
keywords: Li-ion batteries; electrical energy storage; hierarchical hybrids; reduced graphene oxide; supercapacitors; vanadium pentoxides