1
|
Rüdiger C, Valero-Vidal C, Favaro M, Agnoli S, Granozzi G, Kunze-Liebhäuser J. Effect of Air-Aging on the Electrochemical Characteristics of TiO
x
C
y
Films for Electrocatalysis Applications. ChemElectroChem 2017. [DOI: 10.1002/celc.201700912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Celine Rüdiger
- Physik-Department; Technische Universität München; James-Franck-Str. 1 85748 Garching Germany
| | - Carlos Valero-Vidal
- Physik-Department; Technische Universität München; James-Franck-Str. 1 85748 Garching Germany
- Institut für Physikalische Chemie; Leopold-Franzens-Universität Innsbruck; Innrain 52c 6020 Innsbruck Austria
- Advanced Light Source (ALS) and; Joint Center for Energy Storage Research (JCESR), Lawrence Berkeley National Laboratory; 1 Cyclotron Road Berkeley CA 94720 United States
| | - Marco Favaro
- Dipartimento di Scienze Chimiche; Università di Padova Via Marzolo 1 35131 Padova Italy
- Helmholtz-Zentrum Berlin (HZB); Institute for Solar Fuels; Hahn-Meitner-Platz 1 14109 Berlin Germany
| | - Stefano Agnoli
- Dipartimento di Scienze Chimiche; Università di Padova Via Marzolo 1 35131 Padova Italy
| | - Gaetano Granozzi
- Dipartimento di Scienze Chimiche; Università di Padova Via Marzolo 1 35131 Padova Italy
| | - Julia Kunze-Liebhäuser
- Institut für Physikalische Chemie; Leopold-Franzens-Universität Innsbruck; Innrain 52c 6020 Innsbruck Austria
| |
Collapse
|
2
|
Ternary CNTs@TiO₂/CoO Nanotube Composites: Improved Anode Materials for High Performance Lithium Ion Batteries. MATERIALS 2017; 10:ma10060678. [PMID: 28773032 PMCID: PMC5554059 DOI: 10.3390/ma10060678] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/02/2017] [Accepted: 06/16/2017] [Indexed: 11/16/2022]
Abstract
TiO₂ nanotubes (NTs) synthesized by electrochemical anodization are discussed as very promising anodes for lithium ion batteries, owing to their high structural stability, high surface area, safety, and low production cost. However, their poor electronic conductivity and low Li⁺ ion diffusivity are the main drawbacks that prevent them from achieving high electrochemical performance. Herein, we report the fabrication of a novel ternary carbon nanotubes (CNTs)@TiO₂/CoO nanotubes composite by a two-step synthesis method. The preparation includes an initial anodic fabrication of well-ordered TiO₂/CoO NTs from a Ti-Co alloy, followed by growing of CNTs horizontally on the top of the oxide films using a simple spray pyrolysis technique. The unique 1D structure of such a hybrid nanostructure with the inclusion of CNTs demonstrates significantly enhanced areal capacity and rate performances compared to pure TiO₂ and TiO₂/CoO NTs, without CNTs tested under identical conditions. The findings reveal that CNTs provide a highly conductive network that improves Li⁺ ion diffusivity, promoting a strongly favored lithium insertion into the TiO₂/CoO NT framework, and hence resulting in high capacity and an extremely reproducible high rate capability.
Collapse
|
3
|
Portenkirchner E, Neri G, Lichtinger J, Brumbarov J, Rüdiger C, Gernhäuser R, Kunze-Liebhäuser J. Tracking areal lithium densities from neutron activation - quantitative Li determination in self-organized TiO 2 nanotube anode materials for Li-ion batteries. Phys Chem Chem Phys 2017; 19:8602-8611. [PMID: 28290567 DOI: 10.1039/c7cp00180k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Nanostructuring of electrode materials is a promising approach to enhance the performance of next-generation, high-energy density lithium (Li)-ion batteries. Various experimental and theoretical approaches allow for a detailed understanding of solid-state or surface-controlled reactions that occur in nanoscaled electrode materials. While most techniques which are suitable for nanomaterial investigations are restricted to analysis widths of the order of Å to some nm, they do not allow for characterization over the length scales of interest for electrode design, which is typically in the order of mm. In this work, three different self-organized anodic titania nanotube arrays, comprising as-grown amorphous titania nanotubes, carburized anatase titania nanotubes, and silicon coated carburized anatase titania nanotubes, have been synthesized and studied as model composite anodes for use in Li-ion batteries. Their 2D areal Li densities have been successfully reconstructed with a sub-millimeter spatial resolution over lateral electrode dimensions of 20 mm exploiting the 6Li(n,α)3H reaction, in spite of the extremely small areal Li densities (10-20 μg cm-2 Li) in the nanotubular active material. While the average areal Li densities recorded via triton analysis are found to be in good agreement with the electrochemically measured charges during lithiation, triton analysis revealed, for certain nanotube arrays, areas with a significantly higher Li content ('hot spots') compared to the average. In summary, the presented technique is shown to be extremely well suited for analysis of the lithiation behavior of nanostructured electrode materials with very low Li concentrations. Furthermore, identification of lithiation anomalies is easily possible, which allows for fundamental studies and thus for further advancement of nanostructured Li-ion battery electrodes.
Collapse
Affiliation(s)
- E Portenkirchner
- Leopold-Franzens-University Innsbruck, Institute of Physical Chemistry, Innrain 52c, Innsbruck, 6020, Austria.
| | | | | | | | | | | | | |
Collapse
|
4
|
Rüdiger C, Favaro M, Valero-Vidal C, Calvillo L, Bozzolo N, Jacomet S, Hein J, Gregoratti L, Agnoli S, Granozzi G, Kunze-Liebhäuser J. Substrate Grain-Dependent Chemistry of Carburized Planar Anodic TiO 2 on Polycrystalline Ti. ACS OMEGA 2017; 2:631-640. [PMID: 31457460 PMCID: PMC6641173 DOI: 10.1021/acsomega.6b00472] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/27/2017] [Indexed: 06/10/2023]
Abstract
Mixtures or composites of titania and carbon have gained considerable research interest as innovative catalyst supports for low- and intermediate-temperature proton-exchange membrane fuel cells. For applications in electrocatalysis, variations in the local physicochemical properties of the employed materials can have significant effects on their behavior as catalyst supports. To assess microscopic heterogeneities in composition, structure, and morphology, a microscopic multitechnique approach is required. In this work, compact anodic TiO2 films on planar polycrystalline Ti substrates are converted into carbon/titania composites or multiphase titanium oxycarbides through carbothermal treatment in an acetylene/argon atmosphere in a flow reactor. The local chemical composition, structure, and morphology of the converted films are studied with scanning photoelectron microscopy, micro-Raman spectroscopy, and scanning electron microscopy and are related with the crystallographic orientations of the Ti substrate grains by means of electron backscatter diffraction. Different annealing temperatures, ranging from 550 to 850 °C, are found to yield different substrate grain-dependent chemical compositions, structures, and morphologies. The present study reveals individual time scales for the carbothermal conversion and subsequent surface re-oxidation on substrate grains of a given orientation. Furthermore, it demonstrates the power of a microscopic multitechnique approach for studying polycrystalline heterogeneous materials for electrocatalytic applications.
Collapse
Affiliation(s)
- Celine Rüdiger
- Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Marco Favaro
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Carlos Valero-Vidal
- Institut
für Physikalische Chemie, Leopold-Franzens-Universität
Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Laura Calvillo
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Nathalie Bozzolo
- CEMEF
- Centre de Mise en Forme des Matériaux, MINES ParisTech,
PSL Research University, CNRS UMR 7635, CS 10207 Rue Claude Daunesse, 06904 Sophia Antipolis Cedex, France
| | - Suzanne Jacomet
- CEMEF
- Centre de Mise en Forme des Matériaux, MINES ParisTech,
PSL Research University, CNRS UMR 7635, CS 10207 Rue Claude Daunesse, 06904 Sophia Antipolis Cedex, France
| | - Jennifer Hein
- Lehrstuhl
für Technische Chemie II, Technische
Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Luca Gregoratti
- Elettra
− Sincrotrone Trieste SCpA, SS14-Km163.5 in Area Science Park, 34149 Trieste, Italy
| | - Stefano Agnoli
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Gaetano Granozzi
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Julia Kunze-Liebhäuser
- Institut
für Physikalische Chemie, Leopold-Franzens-Universität
Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| |
Collapse
|