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5 results on '"Yannick Lei"'

1. MnO2-coated Ni nanorods: Enhanced high rate behavior in pseudo-capacitive supercapacitor

Author

Frédéric Favier, Yannick Lei, Barbara Daffos, Patrice Simon, Pierre-Louis Taberna, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Supérieure de Chimie de Montpellier - ENSCM (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Montpellier 1 (FRANCE), Université de Montpellier 2 (FRANCE), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Energie électrique, Materials science, Matériaux, General Chemical Engineering, High rate capacitance, Manganese dioxide, Mineralogy, 02 engineering and technology, Substrate (electronics), 010402 general chemistry, Electrochemistry, 01 natural sciences, 7. Clean energy, Coating, chemistry.chemical_compound, Supercapacitor, Anodizing, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Dielectric spectroscopy, chemistry, Chemical engineering, Electrode, Aluminium oxide, Nanorods, Nanorod, 0210 nano-technology
Abstract

International audience; Ni nanorods prepared by electrochemical growth through an anodized aluminium oxide membrane were used as substrate for the electrodeposition of MnO2 either in potentiostatic mode or by a pulsed method. Electrochemical deposition parameters were chosen for an homogeneous deposit onto Ni nanorods. Resulting Ni supportedMnO2 electrodes were tested for electrochemical performances as nanostructured negative electrodes for supercapacitors. They exhibited initial capacitances up to 190 F/g and remarkable performances at high charge/discharge rates.

Published
2010

2. Mesoporous carbon–manganese oxide composite as negative electrode material for supercapacitors

Author

Claire Fournier, Jean-Louis Pascal, Yannick Lei, Frédéric Favier, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, Inorganic chemistry, Composite number, Capacitance, chemistry.chemical_element, 02 engineering and technology, Manganese Oxide, 010402 general chemistry, 01 natural sciences, General Materials Science, Supercapacitor, Nanocomposite, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, Chemical engineering, Mechanics of Materials, Electrode, Mesoporous Carbon, Cyclic voltammetry, 0210 nano-technology, Mesoporous material, Carbon
Abstract

International audience; 3D-assembles of silica spheres were used as hard template to synthesize porous carbon materials with large mesopores to be included as current collectors in supercapacitors and developing large surface areas reaching up to 900m2.g-1. Birnessite-type MnO2 was deposited by a co-precipitation method in the porous network. Electrochemical performances of resulting MnO2/C nanocomposites were evaluated by cyclic voltammetry and showed an initial capacitance and a retained capacitance after 500 cycles for the nanocomposite at 6wt% MnO2 in C of about 660 and 490 F.g-1, respectively.

Published
2008

3. New topotactic synthetic route to mesoporous silicon carbide

Author

Khalil Rajoua, Pengcheng Gao, David Zitoun, Frédéric Favier, Andrès F. Cardozo Pérez, Yannick Lei, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Institute of Nanotechnology and Advanced Materials, and Bar-Ilan University [Israël]

Subjects
Materials science, Composite number, Hexagonal phase, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, General Chemistry, Thermal treatment, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, Mesoporous organosilica, chemistry, Polymerization, Chemical engineering, Materials Chemistry, Silicon carbide, 0210 nano-technology, Mesoporous material, Carbon, ComputingMilieux_MISCELLANEOUS
Abstract

Mesoporous silicon carbide (SiC) was synthesized by a one-pot thermal reduction of SiO2/C composites by metallic Mg at the remarkably low temperature of 800 °C. Two distinct mesostructured silica were used as hard templates for composite preparation: a hexagonal 3D close-packed assembly of Stober silica spheres and an ordered mesoporous SBA15 silica. In the latter case, SiC has crystallized in its 2H–SiC hexagonal phase, which is rather unique at such a low temperature. Composites were obtained by impregnation/polymerisation/carbonisation of a molecular carbon precursor within the porous structure of the silica template. After thermal treatment at a moderate temperature in the presence of Mg and subsequent by-products rinsing off, both prepared SiC showed distinct mesoporous structures related to the initial SiO2 architectures. By comparison of the mesoporous characteristics, resulting SiC was found to retain the carbon structures of the pristine composites. The description of the synthetic mechanism of this topotactic reaction contrasts with the usual assumption stating the templating role of silica.

Published
2011

5. New topotactic synthetic route to mesoporous silicon carbideElectronic supplementary information (ESI) available: Raman spectra of prepared SiC materials, XRD patterns of reaction products from SiO2and carbon black mixture, and corresponding Raman spectrum. See DOI: 10.1039/c1jm12457a

Author

Peng-Cheng Gao, Yannick Lei, Andrès F. Cardozo Pérez, Khalil Rajoua, David Zitoun, and Frédéric Favier

Abstract

Mesoporous silicon carbide (SiC) was synthesized by a one-pot thermal reduction of SiO2/C composites by metallic Mg at the remarkably low temperature of 800 °C. Two distinct mesostructured silica were used as hard templates for composite preparation: a hexagonal 3D close-packed assembly of Stöber silica spheres and an ordered mesoporous SBA15 silica. In the latter case, SiC has crystallized in its 2H–SiC hexagonal phase, which is rather unique at such a low temperature. Composites were obtained by impregnation/polymerisation/carbonisation of a molecular carbon precursor within the porous structure of the silica template. After thermal treatment at a moderate temperature in the presence of Mg and subsequent by-products rinsing off, both prepared SiC showed distinct mesoporous structures related to the initial SiO2architectures. By comparison of the mesoporous characteristics, resulting SiC was found to retain the carbon structures of the pristine composites. The description of the synthetic mechanism of this topotactic reaction contrasts with the usual assumption stating the templating role of silica. [ABSTRACT FROM AUTHOR]

Published
2011
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