The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform

Danielle Gonbeau - One of the best experts on this subject based on the ideXlab platform.

  • Ni3Sn4 Electrodes for Li-Ion Batteries: Li−Sn Alloying Process and Electrode/Electrolyte Interface Phenomena
    Chemistry of Materials, 2008
    Co-Authors: K. K. D. Ehinon, S. Naille, Rémi Dedryvère, Pierre-emmanuel Lippens, Jean-claude Jumas, Danielle Gonbeau
    Abstract:

    We have investigated the reaction mechanisms of lithium toward Ni3Sn4 in an electrochemical cell and the electrode/Electrolyte Interface phenomena in a combined X-ray photoelectron spectroscopy (XPS) and 119Sn Mossbauer spectroscopy approach, which allows a simultaneous analysis of the surface and of the bulk of the active material particles. We show that 4 mol of lithium per mole of Ni3Sn4 are consumed to form the solid Electrolyte Interface (SEI) at the first stage of discharge. The composition and behavior of this SEI have been compared to those observed with graphite. The Li−Sn alloying process occurs in the second stage of discharge to form Li7Sn2. This mechanism is reversible and allows restoring the Ni3Sn4 phase at the end of the cycle.

  • ni3sn4 electrodes for li ion batteries li sn alloying process and electrode Electrolyte Interface phenomena
    Chemistry of Materials, 2008
    Co-Authors: K. K. D. Ehinon, S. Naille, Rémi Dedryvère, Pierre-emmanuel Lippens, Jean-claude Jumas, Danielle Gonbeau
    Abstract:

    We have investigated the reaction mechanisms of lithium toward Ni3Sn4 in an electrochemical cell and the electrode/Electrolyte Interface phenomena in a combined X-ray photoelectron spectroscopy (XPS) and 119Sn Mossbauer spectroscopy approach, which allows a simultaneous analysis of the surface and of the bulk of the active material particles. We show that 4 mol of lithium per mole of Ni3Sn4 are consumed to form the solid Electrolyte Interface (SEI) at the first stage of discharge. The composition and behavior of this SEI have been compared to those observed with graphite. The Li−Sn alloying process occurs in the second stage of discharge to form Li7Sn2. This mechanism is reversible and allows restoring the Ni3Sn4 phase at the end of the cycle.

Zempachi Ogumi - One of the best experts on this subject based on the ideXlab platform.

  • STM study on graphite/Electrolyte Interface in lithium-ion batteries: solid Electrolyte Interface formation in trifluoropropylene carbonate solution
    Electrochimica Acta, 1999
    Co-Authors: Minoru Inaba, Yutaka Kawatate, Atsushi Funabiki, Soon-ki Jeong, Takeshi Abe, Zempachi Ogumi
    Abstract:

    Abstract Lithium intercalation within graphite was studied in an Electrolyte system, 1 M LiClO 4 dissolved in trifluoropropylene carbonate (TFPC). Lithium was intercalated within graphite in TFPC. The reversible capacity obtained (275 mAh g −1 ) was smaller than that in ethylene carbonate-based solutions while the irreversible capacity was larger (335 mAh g −1 ). The morphology change of the basal plane of highly oriented pyrolytic graphite (HOPG) was observed by electrochemical scanning tunneling microscopy (STM) to obtain information about passivating film (solid Electrolyte Interface, SEI) formation in this solvent system. The exfoliation of graphite layers was observed at 1.1 and 1.0 V vs. Li + /Li, and then swelling of graphite layers appeared along step edges at 0.5 V. The feature observed at 0.5 V was considered as SEI itself in this solvent system.

  • stm study on graphite Electrolyte Interface in lithium ion batteries solid Electrolyte Interface formation in trifluoropropylene carbonate solution
    Electrochimica Acta, 1999
    Co-Authors: Minoru Inaba, Yutaka Kawatate, Atsushi Funabiki, Soon-ki Jeong, Takeshi Abe, Zempachi Ogumi
    Abstract:

    Abstract Lithium intercalation within graphite was studied in an Electrolyte system, 1 M LiClO 4 dissolved in trifluoropropylene carbonate (TFPC). Lithium was intercalated within graphite in TFPC. The reversible capacity obtained (275 mAh g −1 ) was smaller than that in ethylene carbonate-based solutions while the irreversible capacity was larger (335 mAh g −1 ). The morphology change of the basal plane of highly oriented pyrolytic graphite (HOPG) was observed by electrochemical scanning tunneling microscopy (STM) to obtain information about passivating film (solid Electrolyte Interface, SEI) formation in this solvent system. The exfoliation of graphite layers was observed at 1.1 and 1.0 V vs. Li + /Li, and then swelling of graphite layers appeared along step edges at 0.5 V. The feature observed at 0.5 V was considered as SEI itself in this solvent system.

Han Chen - One of the best experts on this subject based on the ideXlab platform.

  • Modifying the electrode-Electrolyte Interface of anode supported solid oxide fuel cells (SOFCs) by laser-machining
    Energy Conversion and Management, 2018
    Co-Authors: Yanli Zhang, Yiheng Gu, Lin Ge, Yifeng Zheng, Han Chen
    Abstract:

    Abstract The NiO-yttrium stabilized zirconia (YSZ) anode substrates prepared by tape casting are modified via laser-machining technique in mesoscale for electrode-Electrolyte Interface modification. Two different surface processing methods are applied: (i) scanning the whole surface with continuous tracks to produce a “coarser” surface; (ii) engraving spots on the substrates surface forming “pits array”. The microstructure and electrical performance of the cells based on these anode substrates are investigated. For the scanned anode, confocal laser scanning microscope (CLSM) images show that the surface roughness increases with the laser intensity. The scanning electron microscopy (SEM) images of single cells show that electrode-Electrolyte Interface contact area is increased. Compared with the unmodified cell, the maximum power density of the cells fabricated with “coarser” anode substrates is improved by 47% at 800 °C. For the second case, the SEM images of cross-section of single cells show that the electrode-Electrolyte Interface is wavy, resulting increase in the electrochemically active area. It’s found that the degree of performance enhancement of the cells is related to the pits size, and a suitable diameter and depth of the pits are needed. The highest power density of the cells with “pits array” increases by 55% at 800 °C. In both cases, electrochemistry impedance spectroscopy (EIS) results show that ohmic and polarization resistances of single cells are decreased after modification.

  • Modification of electrode/Electrolyte Interface by laser micro-processing for solid oxide fuel cell
    Materials Letters, 2017
    Co-Authors: Yanli Zhang, Shoucheng He, Lin Ge, Han Chen
    Abstract:

    Abstract A strategy based on laser micro-processing was proposed to improve the solid oxide fuel cell performance by modifying electrode/Electrolyte Interface with a “dimples array” structure. Electrochemistry impedance spectroscopy (EIS) results showed that both ohmic and polarization resistance of single cell were decreased remarkably after interfacial modification. Moreover, the maximum power density of modified cell was increased by up to 58% at 800 °C. The microstructural images of electrode/Electrolyte Interface indicated that the structured Interface extended the triple-phase boundary (TPB) length for electrochemical reaction, which led to the major improvement in the cell performance.

Mamoru Mabuchi - One of the best experts on this subject based on the ideXlab platform.

  • solid Electrolyte Interface phenomena during anodic polarization of pd0 2m0 8 m fe co ni alloys in h2so4
    Journal of Alloys and Compounds, 2010
    Co-Authors: Masataka Hakamada, Kazuki Tajima, Kazuki Yoshimura, Yasumasa Chino, Mamoru Mabuchi
    Abstract:

    Abstract Pd0.2Fe0.8, Pd0.2Co0.8 and Pd0.2Ni0.8 alloys were subjected to electrolysis in H2SO4 for production of nanoporous Pd. Surface analyses with different surface sensitivities revealed that Fe and Ni at the surface layer dissolve in H2SO4 after the electrolysis of Pd0.2Fe0.8 and Pd0.2Ni0.8, respectively, but this dissolution is confined to the surface layer. On the other hand, aggregation of Pd adatoms at the solid/Electrolyte Interface allowed exposure of internal Co atoms to the Electrolyte, and as a result, nanoporosity formed only from Pd0.2Co0.8 alloys. These results experimentally suggest that the aggregation of remnant element (Pd in this case) at solid/Electrolyte Interface is necessary for the formation of nanoporosity by dealloying.

  • Solid/Electrolyte Interface phenomena during anodic polarization of Pd0.2M0.8 (M = Fe, Co, Ni) alloys in H2SO4
    Journal of Alloys and Compounds, 2010
    Co-Authors: Masataka Hakamada, Kazuki Tajima, Kazuki Yoshimura, Yasumasa Chino, Mamoru Mabuchi
    Abstract:

    Abstract Pd0.2Fe0.8, Pd0.2Co0.8 and Pd0.2Ni0.8 alloys were subjected to electrolysis in H2SO4 for production of nanoporous Pd. Surface analyses with different surface sensitivities revealed that Fe and Ni at the surface layer dissolve in H2SO4 after the electrolysis of Pd0.2Fe0.8 and Pd0.2Ni0.8, respectively, but this dissolution is confined to the surface layer. On the other hand, aggregation of Pd adatoms at the solid/Electrolyte Interface allowed exposure of internal Co atoms to the Electrolyte, and as a result, nanoporosity formed only from Pd0.2Co0.8 alloys. These results experimentally suggest that the aggregation of remnant element (Pd in this case) at solid/Electrolyte Interface is necessary for the formation of nanoporosity by dealloying.

K. K. D. Ehinon - One of the best experts on this subject based on the ideXlab platform.

  • Ni3Sn4 Electrodes for Li-Ion Batteries: Li−Sn Alloying Process and Electrode/Electrolyte Interface Phenomena
    Chemistry of Materials, 2008
    Co-Authors: K. K. D. Ehinon, S. Naille, Rémi Dedryvère, Pierre-emmanuel Lippens, Jean-claude Jumas, Danielle Gonbeau
    Abstract:

    We have investigated the reaction mechanisms of lithium toward Ni3Sn4 in an electrochemical cell and the electrode/Electrolyte Interface phenomena in a combined X-ray photoelectron spectroscopy (XPS) and 119Sn Mossbauer spectroscopy approach, which allows a simultaneous analysis of the surface and of the bulk of the active material particles. We show that 4 mol of lithium per mole of Ni3Sn4 are consumed to form the solid Electrolyte Interface (SEI) at the first stage of discharge. The composition and behavior of this SEI have been compared to those observed with graphite. The Li−Sn alloying process occurs in the second stage of discharge to form Li7Sn2. This mechanism is reversible and allows restoring the Ni3Sn4 phase at the end of the cycle.

  • ni3sn4 electrodes for li ion batteries li sn alloying process and electrode Electrolyte Interface phenomena
    Chemistry of Materials, 2008
    Co-Authors: K. K. D. Ehinon, S. Naille, Rémi Dedryvère, Pierre-emmanuel Lippens, Jean-claude Jumas, Danielle Gonbeau
    Abstract:

    We have investigated the reaction mechanisms of lithium toward Ni3Sn4 in an electrochemical cell and the electrode/Electrolyte Interface phenomena in a combined X-ray photoelectron spectroscopy (XPS) and 119Sn Mossbauer spectroscopy approach, which allows a simultaneous analysis of the surface and of the bulk of the active material particles. We show that 4 mol of lithium per mole of Ni3Sn4 are consumed to form the solid Electrolyte Interface (SEI) at the first stage of discharge. The composition and behavior of this SEI have been compared to those observed with graphite. The Li−Sn alloying process occurs in the second stage of discharge to form Li7Sn2. This mechanism is reversible and allows restoring the Ni3Sn4 phase at the end of the cycle.