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2. Improved electro-grafting of nitropyrene onto onion-like carbon via in situ electrochemical reduction and polymerization: Tailoring redox energy density of the supercapacitor positive electrode

Author

Anothumakkool, Bihag, Sayed-Ahmad-Baraza, Yuman, Ewels, Chris, Taberna, Pierre-Louis, Daffos, Barbara, Simon, Patruce, Brousse, Thierry, and Gaubicher, Joel

Subjects
Condensed Matter - Materials Science
Abstract

Herein, we report a improved method for the physical grafting of 1-nitropyrene (Pyr-NO2) onto highly graphitized carbon onion. This is achieved through a lowering of the onset potential of the pyrene polymerization via in situ reduction of the NO2 group. The additional redox activity pertaining to the reduced NO2 enables exceeding the faradaic capacity which is associated with the p-doping of the grafted pyrene backbone, as observed for pyrene, 1-aminopyrene, and unreduced Pyr- NO2. Theoretical calculations demonstrate the charge transfer and binding enthalpy capabilities of Pyr-NO2, which are significantly higher than those of the other two species, and which allow for improved p-stacking on the carbon surface. Upon 20 wt % grafting of Pyr-NO2, the capacity of the electrode jumps from 20 mAh g-1 electrode to 38 mAh g- electrode, which corresponds to 110 mAh g-1 per mass of Pyr-NO2 and the average potential is increased by 200 mV. Very interestingly, this high performance is also coupled with outstanding retention with respect to both the initial capacity for more than 4000 cycles, as well as the power characteristics, demonstrating the considerable advantages of employing the present in situ grafting technique.

Published
2019
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4. Capacitance of Nanoporous Carbon-Based Supercapacitors is a Trade-Off Between the Concentration and the Separability of the Ions

Author

Burt, Ryan, Breitsprecher, Konrad, Daffos, Barbara, Taberna, Pierre-Louis, Simon, Patrice, Birkett, Greg, Zhao, X. S., Holm, Christian, and Salanne, Mathieu

Subjects
Condensed Matter - Materials Science
Abstract

Nanoporous carbon-based supercapacitors store electricity through adsorption of ions from the electrolyte at the surface of the electrodes. Room temperature ionic liquids, which show the largest ion concentrations among organic liquid electrolytes, should in principle yield larger capacitances. Here we show by using electrochemical measurements that the capacitance is not significantly affected when switching from a pure ionic liquid to a conventional organic electrolyte using the same ionic species. By performing additional molecular dynamics simulations, we interpret this result as an increasing difficulty of separating ions of opposite charges when they are more concentrated, i.e. in the absence of a solvent which screens the Coulombic interactions. The charging mechanism consistently changes with ion concentration, switching from counter-ion adsorption in the diluted organic electrolyte to ion exchange in the pure ionic liquid. Contrarily to the capacitance, in-pore diffusion coefficients largely depend on the composition, with a noticeable slowing of the dynamics in the pure ionic liquid., Comment: 8 pages, 6 figures

Published
2017
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15. Tuning the Surface Chemistry of MXene to Improve Energy Storage: Example of Nitrification by Salt Melt.

Author

Liu, Liyuan, Zschiesche, Hannes, Antonietti, Markus, Daffos, Barbara, Tarakina, Nadezda V., Gibilaro, Mathieu, Chamelot, Pierre, Massot, Laurent, Duployer, Benjamin, Taberna, Pierre‐Louis, and Simon, Patrice

Subjects
SURFACE chemistry, NITRIFICATION, SURFACE conductivity, ELECTRIC conductivity, FUSED salts, IRON chlorides, AQUEOUS electrolytes, ENERGY storage
Abstract

The unique properties of 2D MXenes, such as metal‐like electrical conductivity and versatile surface chemistry, make them appealing for various applications, including energy storage. While surface terminations of 2D MXene are expected to have a key influence on their electrochemical properties, the conventional HF‐etching method limits the surface functional groups to F, OH, and O. In this study, O‐free, Cl‐terminated MXenes (noted as Ti3C2Clx) are first synthesized by a molten salt (FeCl2) etching route. Then, a substitution of surface termination from Cl to N is performed via post‐thermal treatment of Ti3C2Clx in Li3N containing molten salt electrolytes. While the Cl‐terminated pristine material does not show electrochemical activity, the surface‐modified, N‐containing Ti3C2Tx exhibits a unique capacitive‐like electrochemical signature in sulfuric acid aqueous electrolyte with rate performance—more than 300 F g−1 (84 mAh g−1) at 2 V s−1. These results show that control of the MXene surface chemistry enables the preparation of high‐performance electrodes in a previously not accessed limit of energy storage. [ABSTRACT FROM AUTHOR]

Published
2023
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25. (Invited) A Versatile Approach for Pre-Lithiation of LIC and Increase of Their Energy Density Via Pyrene Chemistry

Author

Gaubicher, Joël, primary, Anothumakkool, Bihag, additional, Ahmad-Baraza, Yuman Sayed, additional, Wiemers-Meyer, Simon, additional, Taberna, Pierre-Louis, additional, Daffos, Barbara, additional, Simon, Patrice, additional, Ewels, Chris, additional, Guyomard, Dominique, additional, Winter, Martin, additional, and Brousse, Thierry, additional

Published
2019
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30. Capacitance of Ti3C2Tx MXene in ionic liquid electrolyte

Author

Daffos Barbara, Yury Gogotsi, Babak Anasori, Patrice Simon, Zifeng Lin, Katherine L. Van Aken, Pierre-Louis Taberna, Centre National de la Recherche Scientifique - CNRS (FRANCE), Drexel University (USA), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UPS (FRANCE), Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France), Réseau sur le Stockage Electrochimique de l'Energie - RS2E (Amiens, France), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), 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), Réseau sur le stockage électrochimique de l'énergie (RS2E), Université de Picardie Jules Verne (UPJV)-Institut de Chimie du CNRS (INC)-Aix Marseille Université (AMU)-Université de Pau et des Pays de l'Adour (UPPA)-Université de Nantes (UN)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Drexel University, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université de Nantes (UN)-Aix Marseille Université (AMU)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Université de Picardie Jules Verne (UPJV)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Materials science, Matériaux, Analytical chemistry, Energy Engineering and Power Technology, 02 engineering and technology, Electrolyte, Ionic liquid, 010402 general chemistry, Electrochemistry, 7. Clean energy, 01 natural sciences, Capacitance, Carbide, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Supercapacitors, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Ionogel, Horizontal scan rate, Supercapacitor, Renewable Energy, Sustainability and the Environment, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Ti3C2Tx, chemistry, Electrode, 0210 nano-technology, MXene
Abstract

International audience; Ti3C2Tx MXene, a two-dimensional (2D) early transition metal carbide, has shown an extremely high volumetric capacitance in aqueous electrolytes, but in a narrow voltage window (less than 1.23 V). The utilization of MXene materials in ionic liquid electrolytes with a large voltage window has never been addressed. Here, we report the preparation of the Ti3C2Tx MXene ionogel film by vacuum filtration for use as supercapacitor electrodes operating in 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI) neat ionic liquid electrolyte. Due to the disordered structure of the Ti3C2Tx hydrogel film and a stable spacing after vacuum drying, achieved through ionic liquid electrolyte immersion of the Ti3C2Tx hydrogel film, the Ti3C2Tx surface became accessible to EMI+ and TFSI− ions. A capacitance of 70 F g−1 together with a large voltage window of 3 V was obtained at a scan rate of 20 mV s−1 in neat EMI-TFSI electrolyte. The electrochemical signature indicates a capacitive behavior even at a high scan rate (500 mV s−1) and a high power performance. This work opens up the possibilities of using MXene materials with various ionic liquid electrolytes.

Published
2016

34. Thin Film Electrodes for Fast Electrochemical Micro-Supercapacitors

Author

Arico, Cassandra, primary, Robert, Kevin, additional, Brousse, Kevin, additional, Ouendi, Saliha, additional, Douard, Camille, additional, Daffos, Barbara, additional, Taberna, Pierre-Louis, additional, Roussel, Pascal, additional, Le Bideau, Jean, additional, Simon, Patrice, additional, Brousse, Thierry, additional, and Lethien, Christophe, additional

Published
2017
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36. Sputtered Titanium Carbide Thick Film for High Areal Energy on Chip Carbon‐Based Micro‐Supercapacitors

Author

Létiche, Manon, primary, Brousse, Kevin, additional, Demortière, Arnaud, additional, Huang, Peihua, additional, Daffos, Barbara, additional, Pinaud, Sébastien, additional, Respaud, Marc, additional, Chaudret, Bruno, additional, Roussel, Pascal, additional, Buchaillot, Lionel, additional, Taberna, Pierre Louis, additional, Simon, Patrice, additional, and Lethien, Christophe, additional

Published
2017
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46. Design of Fe3–xO4raspberry decorated graphene nanocomposites with high performances in lithium-ion battery

Author

Gerber, Olivier, Bégin-Colin, Sylvie, Pichon, Benoit P., Barraud, Elodie, Lemonnier, Sébastien, Pham-Huu, Cuong, Daffos, Barbara, Simon, Patrice, Come, Jeremy, and Bégin, Dominique

Abstract

Fe3–xO4raspberry shaped nanostructures/graphene nanocomposites were synthesized by a one-step polyol-solvothermal method to be tested as electrode materials for Li-ion battery (LIB). Indeed, Fe3–xO4raspberry shaped nanostructures consist of original oriented aggregates of Fe3–xO4magnetite nanocrystals, ensuring a low oxidation state of magnetite and a hollow and porous structure, which has been easily combined with graphene sheets. The resulting nanocomposite powder displays a very homogeneous spatial distribution of Fe3–xO4nanostructures at the surface of the graphene sheets. These original nanostructures and their strong interaction with the graphene sheets resulted in very small capacity fading upon Li+ion intercalation. Reversible capacity, as high as 660mAh/g, makes this material promising for anode in Li-ion batteries application.

Published
2016
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47. From molecule-based (super)conductors to thin films, nanowires and nanorings.

Author

Cassoux, Patrick, De Caro, Dominique, Valade, Lydie, Casellas, Hélène, Daffos, Barbara, and Elena Sanchez Vergara, Maria

Abstract

Thin films of (TTF)(TCNQ) (TTF=tetrathiafulvalene, TCNQ=tetracyanoquinodimethane) are deposited on Si (001), KBr, and stainless steel conversion coatings (SSCC) using chemical vapor deposition. These films are characterized by IR, XRD, conductivity measurements, and SEM. Conducting nanowires and nanorings of (TTF)(TCNQ) and nanowires of (TTF)[Ni(dmit) 2 ] 2 (typically, 20 nm×20 μm) are prepared by successively dipping SSCC in acetonitrile solutions of TTF and TCNQ, or (TTF) 3 (BF 4 ) and (Bu 4 N)[Ni(dmit) 2 ], respectively. These nanowires are observed by SEM. The (TTF)(TCNQ) nanowires are also observed by TEM and AFM and characterized by current-voltage measurements. Nanowires of (TTF)[Ni(dmit) 2 ] 2 are also obtained on silicon conversion coatings (SiCC) and characterized by Raman spectroscopy. [ABSTRACT FROM PUBLISHER]

Published
2003
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48. The effects of local graphitization on the charging mechanisms of microporous carbon supercapacitor electrodes

Author

Yin, Huan, Shao, Hui, Daffos, Barbara, Taberna, Pierre-Louis, Simon, Patrice, SAFEGE, Safege company, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)

Subjects
Nanoporous carbon, Electrical double-layer capacitance, Charge storage mechanism, Electrochemical quartz crystal microbalance, [CHIM.MATE]Chemical Sciences/Material chemistry
Abstract

International audience; The electrochemical quartz crystal microbalance (EQCM) technique has been used to study the charge mechanisms in two TiC-derived nanoporous carbons (CDC), synthesized at 800 ℃ and 1100 ℃. These two carbons have a similar pore size and porous volume, but the CDC prepared at 1100 • C shows a more graphitic microstructure. The EQCM study revealed that the charge storage mechanism in the CDC-800 is mainly controlled by a counterion adsorption process, while an expanded ion-exchange process was observed for the CDC-1100. Combined with the potential of zero charge (PZC), these measurements suggest a strong interaction between the anions and graphitic carbon. For the first time, we provide experimental evidence that the local carbon structure affects the charge storage mechanism of the electrical double-layer capacitance in high surface area porous carbons.

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49. Thermal Oxidation of Carbonaceous Nanomaterials Revisited: Evidence of Mechanism Changes.

Author

Picheau E, Hof F, Derré A, Daffos B, and Pénicaud A

Abstract

Kinetic data, for example, activation energy and reaction order, are crucial for the understanding of chemical reactions and processes. Here, we describe a novel method for obtaining kinetic data based on thermogravimetric measurements (TGA) that exploits in each measurement multiple successive isothermal steps (SIS). We applied this method to the notoriously challenging carbon combustion process for vastly different carbons for oxygen molar fractions between 1.4 % and 90 %. Our obtained apparent E A values are within the wide range of results in the literature and vary in a systematic way with the oxygen partial pressure. The improved accuracy and large amount of obtainable data allowed us to show that the majority of experimentally obtained apparent data for apparent E A are neither in a kinetic regime nor in a diffusion-controlled one but rather in a transition regime., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2019
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