Electrochemical Energy Storage Applications of CVD Grown Niobium Oxide Thin Films

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• 作者：Raquel Fiz ; Linus Appel ; Antonio Gutiérrez-Pardo ; Joaquín Ramírez-Rico ; Sanjay Mathur
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：August 24, 2016
• 年：2016
• 卷：8
• 期：33
• 页码：21423-21430
• 全文大小：590K
• 年卷期：0
• ISSN：1944-8252

文摘

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 gp>–1p>, while imparting good cycling stability, making these materials ideally suited for electrochemical energy storage applications.