Designing Pseudocapacitance for Nb2O5/Carbide-Derived Carbon Electrodes and Hybrid Devices.

Title Designing Pseudocapacitance for Nb2O5/Carbide-Derived Carbon Electrodes and Hybrid Devices.
Authors C.H. Lai; D. Ashby; M. Moz; Y. Gogotsi; L. Pilon; B. Dunn
Journal Langmuir
DOI 10.1021/acs.langmuir.7b01110
Abstract

Composite structures for electrochemical energy storage are prepared on the basis of using the high-rate lithium ion insertion properties of Nb2O5. The Nb2O5 is anchored on reduced graphene oxide (rGO) by hydrothermal synthesis to improve the charge-transfer properties, and by controlling the surface charge, the resulting Nb2O5-rGO particles are attached to a high-surface-area carbide-derived carbon scaffold without blocking its exfoliated layers. The electrochemical results are analyzed using a recently published multiscale physics model that provides significant insights regarding charge storage kinetics. In particular, the composite electrode exhibits surface-confined charge storage at potentials of <1.7 V (vs Li/Li(+)), where faradaic processes dominate, and electrical double layer charge storage at potentials of >2.2 V. A hybrid device composed of the composite electrode with activated carbon as the positive electrode demonstrates increased energy density at power densities comparable to an activated carbon device, provided the hybrid device operates in the faradaic potential range.

Citation C.H. Lai; D. Ashby; M. Moz; Y. Gogotsi; L. Pilon; B. Dunn.Designing Pseudocapacitance for Nb2O5/Carbide-Derived Carbon Electrodes and Hybrid Devices.. Langmuir. 2017;33(37):94079415. doi:10.1021/acs.langmuir.7b01110

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See more Niobium products. Niobium (atomic symbol: Nb, atomic number: 41) is a Block D, Group 5, Period 5 element with an atomic weight of 92.90638. Niobium Bohr ModelThe number of electrons in each of niobium's shells is 2, 8, 18, 12, 1 and its electron configuration is [Kr] 4d4 5s1. The niobium atom has a radius of 146 pm and a Van der Waals radius of 207 pm. Niobium was discovered by Charles Hatchett in 1801 and first isolated by Christian Wilhelm Blomstrand in 1864. In its elemental form, niobium has a gray metallic appearance. Niobium has the largest magnetic penetration depth of any element and is one of three elemental type-II superconductors (Elemental Niobiumalong with vanadium and technetium). Niobium is found in the minerals pyrochlore, its main commercial source, and columbite. The word Niobium originates from Niobe, daughter of mythical Greek king Tantalus.

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