title: Electrochemical Energy Storage Applications of CVD Grown Niobium Oxide Thin Films.
abstract: We report here on the controlled synthesis, characterization, and electrochemical properties of different polymorphs of niobium pentoxide grown by CVD of new single-source precursors. Nb2O5 films deposited at different temperatures showed systematic phase evolution from low-temperature tetragonal (TT-Nb2O5, T-Nb2O5) to high temperature monoclinic modifications (H-Nb2O5). Optimization of the precursor flux and substrate temperature enabled phase-selective growth of Nb2O5 nanorods and films on conductive mesoporous biomorphic carbon matrices (BioC). Nb2O5 thin films deposited on monolithic BioC scaffolds produced composite materials integrating the high surface area and conductivity of the carbonaceous matrix with the intrinsically high capacitance of nanostructured niobium oxide. Heterojunctions in Nb2O5/BioC composites were found to be beneficial in electrochemical capacitance. Electrochemical characterization of Nb2O5/BioC composites showed that small amounts of Nb2O5 (as low as 5%) in conjunction with BioCarbon resulted in a 7-fold increase in the electrode capacitance, from 15 to 104 F g(-1), while imparting good cycling stability, making these materials ideally suited for electrochemical energy storage applications.
authors.affiliation: Institute of Inorganic Chemistry, University of Cologne , Greinstraße 6, 50939, Cologne, Germany.
authors.forename: Raquel
authors.initials: R
authors.lastname: Fiz
authors.affiliation: Institute of Inorganic Chemistry, University of Cologne , Greinstraße 6, 50939, Cologne, Germany.
authors.forename: Linus
authors.initials: L
authors.lastname: Appel
authors.affiliation: Institute of Inorganic Chemistry, University of Cologne , Greinstraße 6, 50939, Cologne, Germany.|Departamento Fisica de la Materia Condensada-ICMS ( Universidad de Sevilla-CSIC ), Avda Reina Mercedes s/n, 41012 Seville, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gutiérrez-Pardo
authors.affiliation: Departamento Fisica de la Materia Condensada-ICMS ( Universidad de Sevilla-CSIC ), Avda Reina Mercedes s/n, 41012 Seville, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Ramírez-Rico
authors.affiliation: Institute of Inorganic Chemistry, University of Cologne , Greinstraße 6, 50939, Cologne, Germany.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mathur
keywords: biomorphic carbon; chemical vapor deposition; electrochemical energy storage; niobium oxides; precursors