NEXAFS and X-ray scattering study of structure changes after post-annealing treatments of aligned MWNTs

Bouchet-Fabre, B.; Pinault, Mathieu; Pichot, Vincent; Launois, Pascale; Mayne-l'Hermite, M.; Parent, Ph.; Laffon, K.; Durand, Dominique; Reynaud, C.

doi:10.1016/j.diamond.2004.11.018

Cited by 12 publications

(11 citation statements)

References 12 publications

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“…Its diffraction peaks are no more visible on the scattering pattern of the annealed sample, indicating that cementite nanoparticles have been removed during the annealing step. The same result holds for other iron‐based nanoparticles present in the raw carpet, such as γ‐iron . However, if amorphized, iron nanoparticles would no more be visible in diffraction experiment.…”

Section: Resultssupporting

confidence: 61%

Vertically aligned carbon nanotube‐based composite: Elaboration and monitoring of the nanotubes alignment

Huard

Roussel

Rouzière

et al. 2013

J of Applied Polymer Sci

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International audienceWe present the different elaboration steps of a composite formed of carbon nanotubes (CNT) carpet embedded in an epoxy polymer. Detailed characterization at each step of the elaboration process is performed. The good alignment of CNT in as-grown carpets is kept all along the elaboration process of the composite, as it is measured at both macro and microscopic scales by X-ray scattering. We also ensured by X-ray fluorescence measurements that the iron-based catalyst particles used for the synthesis were removed from the carpet after a high temperature post-annealing treatment. These measurements give valuable information for further applications involving unidirectional nanotube composites and membranes, where CNT alignment is a key parameter

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Section: Resultssupporting

confidence: 61%

Vertically aligned carbon nanotube‐based composite: Elaboration and monitoring of the nanotubes alignment

Huard

Roussel

Rouzière

et al. 2013

J of Applied Polymer Sci

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“…In order to verify the aforementioned phenomena of the limited formation of SEI thin film with CBN35 carbon black electrodes, the surface sensitive TEY-mode C K-edge X-ray absorption spectra at different electrochemical states in DEGDME-based electrolyte are displayed in Fig.6(d). For pristine electrodes, sharp peaks at 285.4 eV and 292.4 eV can be found and are attributed to carbon 1s core electrons excited to π(C-C)* and σ(C-C)* orbitals 91 , respectively, while the small peak around 288.3 eV may be related to π (C=O)* transitions [91][92][93][94] .…”

Section: Resultsmentioning

confidence: 98%

Boosting the sodium storage behaviors of carbon materials in ether-based electrolyte through the artificial manipulation of microstructure

et al. 2019

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The porous carbon blacks rationally designed by an NH3 etching route have been investigated as anode materials in DEGDME (Diethylene glycol dimethyl ether)-based electrolyte for sodium-ion batteries. The as-synthesized CBN35 carbon black with highest microporosity and appropriate surface area, exhibits a large specific charge capacity of 352 mAh g-1 at 50 mA g-1 and a superior rate capability of 125 mAh g-1 at 3200 mA g-1. Even cycled at 1600 mA g-1 over 3200 cycles, an outstanding reversible capacity of 103 mAh g-1 with a negligible 0.0162% capacity loss per cycle can still be achieved. Based on multimodal characterizations, including the structural probe of the evolution of carbon materials, the electrochemical techniques, and surface-sensitive XAS measurements, the exceptional electrochemical properties stem from several advantages of the modified carbon black system. The particular microporous structure provides relatively more accessible sodium storage sites and a hybrid insertion mechanism with sodium ion insertion into disordered structure while solvated sodium ion intercalation into graphitic phase. The system also features a controlled emergence of a robust SEI thin film, which could maintain the fragile porous structure and facilitate the sodium ions/solvated sodium ion migration.

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“…The formation and evolution of SEI for CBC13 carbon black electrodes in DEGDMEbased electrolyte were also investigated by the highly surface-sensitive C K-edge X-ray absorption spectroscopies in TEY (Total Electron Yield) mode, as shown in Figure 5(d). For the pristine CBC13 carbon black, two obvious features at 285.4 and 292.4 eV should correspond to the transitions of C 1s electrons toward the π*(C-C) and σ*(C-C) orbitals 110 , respectively, while the peak at 288.2 eV is related to the π*(C=O) transitions [110][111][112][113] . Upon discharging to 0.001 V, the peaks for the π*(C-C) and π*(C=O) transitions shift negatively and the σ*(C-C) feature completely disappears.…”

Section: Resultsmentioning

confidence: 99%

“…The formation and evolution of SEI on CBC13 carbon black electrodes in the DEGDME-based electrolyte were also investigated by the highly surface-sensitive C K-edge XAS in the TEY mode, as shown in Figure d. For the pristine CBC13 carbon black, two obvious features at 285.4 and 292.4 eV should correspond to the transitions of C 1s electrons toward the π*(C–C) and σ*(C–C) orbitals, respectively, while the peak at 288.2 eV is related to the π*(CO) transitions. − Upon discharging to 0.001 V, the peaks for the π*(C–C) and π*(CO) transitions shift negatively, and the σ*(C–C) feature completely disappears. Importantly, a newly formed sharp peak around 290.0 eV attributed to the σ*(C–O) transitions for the oxygen-containing functional groups ,, and a broad peak around 301.0 eV as the σ*(CO) feature ,, can be clearly identified in the XAS measurement, as a strong evidence for electrolyte decomposition and subsequent SEI generation.…”

Section: Resultsmentioning

confidence: 99%

Engineering Surface Oxygenated Functionalities on Commercial Carbon toward Ultrafast Sodium Storage in Ether-Based Electrolytes

Xiao

Sun

Liu

et al. 2020

ACS Appl. Mater. Interfaces

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The pursuit of a high-capacity anode material has been urgently required for commercializing sodium-ion batteries with a high energy density and an improved safety. In the absence of the thermodynamically stable sodium intercalated compounds with graphite, constructing nanostructures with expanded interlayer distances is still the mainstream of developing highperformance carbonaceous anodes. In this regard, a porous carbon material has been fabricated by a facile CO 2 thermal etching process and the great importance of oxygenated functionalities for sodium ion storage is firstly uncovered by the electrochemical and physiochemical characterizations. Due to the abundant ionic/electronic pathways and more active sodium storage sites in microporous structure with the noticeable pseudocapacitive behaviors, the functionalized porous carbon could achieve a highly reversible capacity of 505 mAh g -1 at 50 mA g -1 , an excellent rate performance of 181 mAh g -1 at 16000 mA g -1 , and an exceptional rate cycle stability of 176 mAh g -1 at 3200 mA g -1 over 1000 cycles. These outstanding electrochemical performances should be attributed to a synergistic mechanism, fully utilizing the graphitic and amorphous structures for the simultaneous intercalations of sodium ions and solvated sodium ion species, respectively. Additionally, the controllable formation and evolution of a robust but thin solid electrolyte interphase (SEI) film with the emergence of obvious capacitive reactions on defective surface, favoring the rapid migrations of sodium ions and solvated compounds, also contribute to the remarkable electrochemical performances of the porous carbon black.

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NEXAFS and X-ray scattering study of structure changes after post-annealing treatments of aligned MWNTs

Cited by 12 publications

References 12 publications

Vertically aligned carbon nanotube‐based composite: Elaboration and monitoring of the nanotubes alignment

Vertically aligned carbon nanotube‐based composite: Elaboration and monitoring of the nanotubes alignment

Boosting the sodium storage behaviors of carbon materials in ether-based electrolyte through the artificial manipulation of microstructure

Engineering Surface Oxygenated Functionalities on Commercial Carbon toward Ultrafast Sodium Storage in Ether-Based Electrolytes

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