The Experts below are selected from a list of 30354 Experts worldwide ranked by ideXlab platform

Patrice Simon - One of the best experts on this subject based on the ideXlab platform.

  • Li4Ti5O12/poly(methyl)thiophene asymmetric hybrid Electrochemical Device
    Journal of Power Sources, 2004
    Co-Authors: Aurelien Du Pasquier, Alexis Laforgue, Patrice Simon
    Abstract:

    Abstract Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid Electrochemical Device with a nano-structured Li4Ti5O12 anode. This Device displays the specific power of a supercapacitor, with a higher specific energy of 10 Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.

  • li4ti5o12 poly methyl thiophene asymmetric hybrid Electrochemical Device
    Journal of Power Sources, 2004
    Co-Authors: Aurelien Du Pasquier, Alexis Laforgue, Patrice Simon
    Abstract:

    Abstract Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid Electrochemical Device with a nano-structured Li4Ti5O12 anode. This Device displays the specific power of a supercapacitor, with a higher specific energy of 10 Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.

Maria Forsyth - One of the best experts on this subject based on the ideXlab platform.

  • probing ion exchange in the triflic acid guanidinium triflate system a solid state nuclear magnetic resonance study
    Journal of Physical Chemistry C, 2014
    Co-Authors: Haijin Zhu, Douglas R Macfarlane, Maria Forsyth
    Abstract:

    Knowledge of ion exchange and transport behavior in electrolyte materials is crucial for designing and developing novel electrolytes for Electrochemical Device applications such as fuel cells or batteries. In the present study, we show that, upon the addition of triflic acid (HTf) to the guanidinium triflate (GTf) solid-state matrix, several orders of magnitude enhancement in the proton conductivity can be achieved. The static 1H and 19F solid-state NMR results show that the addition of HTf has no apparent effect on local molecular mobility of the GTf matrix at room temperature. At higher temperatures, however, the HTf exhibits fast ion exchange with the GTf matrix. The exchange rate, as quantified by our continuum T2 fitting analysis, increases with increasing temperature. The activation energy for the chemical exchange process was estimated to be 58.4 kJ/mol. It is anticipated that the solid-state NMR techniques used in this study may be also applied to other organic solid-state electrolyte systems to i...

  • proton transport behaviour and molecular dynamics in the guanidinium triflate solid and its mixtures with triflic acid
    Journal of Materials Chemistry, 2014
    Co-Authors: Haijin Zhu, Douglas R Macfarlane, Usman Ali Rana, Vijayaraghavan Ranganathan, Liyu Jin, Luke A Odell, Maria Forsyth
    Abstract:

    Knowledge of the proton transport behaviour in electrolyte materials is crucial for designing and developing novel solid electrolytes for Electrochemical Device applications such as fuel cells or batteries. In the present work, high proton conductivity (approximately 10−3 S cm−1) was observed in the triflic acid (HTf) containing guanidinium triflate (GTf) composites. The proton transport mechanism in the composite was elucidated by comparing the diffusion coefficients obtained from NMR and conductivity measurements. Several orders of magnitude enhancement of conductivity is observed upon addition of HTf to the organic solid, and this appears to follow percolation behaviour with a percolation threshold of approximately 2% HTf. The data support a structural diffusion (or Grotthuss) mechanism of proton transport with a calculated Haven ratio significantly less than unity. 13C SUPER and 14N overtone NMR experiments were used to study the mobility and symmetry of the triflate anion and guanidinium cation respectively at a molecular level. The former experiment shows that the CF3 group in the anion displays fast and isotropic motion at room temperature. In contrast to the high mobility of the anion group, the 14N overtone experiments indicate that the guanidinium cation is static in both the pure and the acid-containing GTf samples at room temperature. It is anticipated that these solid-state NMR techniques may be also applied to other organic solid state electrolyte materials to achieve a better understanding of their transport mechanisms and molecular dynamics.

Aurelien Du Pasquier - One of the best experts on this subject based on the ideXlab platform.

  • Li4Ti5O12/poly(methyl)thiophene asymmetric hybrid Electrochemical Device
    Journal of Power Sources, 2004
    Co-Authors: Aurelien Du Pasquier, Alexis Laforgue, Patrice Simon
    Abstract:

    Abstract Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid Electrochemical Device with a nano-structured Li4Ti5O12 anode. This Device displays the specific power of a supercapacitor, with a higher specific energy of 10 Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.

  • li4ti5o12 poly methyl thiophene asymmetric hybrid Electrochemical Device
    Journal of Power Sources, 2004
    Co-Authors: Aurelien Du Pasquier, Alexis Laforgue, Patrice Simon
    Abstract:

    Abstract Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid Electrochemical Device with a nano-structured Li4Ti5O12 anode. This Device displays the specific power of a supercapacitor, with a higher specific energy of 10 Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.

Haijin Zhu - One of the best experts on this subject based on the ideXlab platform.

  • probing ion exchange in the triflic acid guanidinium triflate system a solid state nuclear magnetic resonance study
    Journal of Physical Chemistry C, 2014
    Co-Authors: Haijin Zhu, Douglas R Macfarlane, Maria Forsyth
    Abstract:

    Knowledge of ion exchange and transport behavior in electrolyte materials is crucial for designing and developing novel electrolytes for Electrochemical Device applications such as fuel cells or batteries. In the present study, we show that, upon the addition of triflic acid (HTf) to the guanidinium triflate (GTf) solid-state matrix, several orders of magnitude enhancement in the proton conductivity can be achieved. The static 1H and 19F solid-state NMR results show that the addition of HTf has no apparent effect on local molecular mobility of the GTf matrix at room temperature. At higher temperatures, however, the HTf exhibits fast ion exchange with the GTf matrix. The exchange rate, as quantified by our continuum T2 fitting analysis, increases with increasing temperature. The activation energy for the chemical exchange process was estimated to be 58.4 kJ/mol. It is anticipated that the solid-state NMR techniques used in this study may be also applied to other organic solid-state electrolyte systems to i...

  • proton transport behaviour and molecular dynamics in the guanidinium triflate solid and its mixtures with triflic acid
    Journal of Materials Chemistry, 2014
    Co-Authors: Haijin Zhu, Douglas R Macfarlane, Usman Ali Rana, Vijayaraghavan Ranganathan, Liyu Jin, Luke A Odell, Maria Forsyth
    Abstract:

    Knowledge of the proton transport behaviour in electrolyte materials is crucial for designing and developing novel solid electrolytes for Electrochemical Device applications such as fuel cells or batteries. In the present work, high proton conductivity (approximately 10−3 S cm−1) was observed in the triflic acid (HTf) containing guanidinium triflate (GTf) composites. The proton transport mechanism in the composite was elucidated by comparing the diffusion coefficients obtained from NMR and conductivity measurements. Several orders of magnitude enhancement of conductivity is observed upon addition of HTf to the organic solid, and this appears to follow percolation behaviour with a percolation threshold of approximately 2% HTf. The data support a structural diffusion (or Grotthuss) mechanism of proton transport with a calculated Haven ratio significantly less than unity. 13C SUPER and 14N overtone NMR experiments were used to study the mobility and symmetry of the triflate anion and guanidinium cation respectively at a molecular level. The former experiment shows that the CF3 group in the anion displays fast and isotropic motion at room temperature. In contrast to the high mobility of the anion group, the 14N overtone experiments indicate that the guanidinium cation is static in both the pure and the acid-containing GTf samples at room temperature. It is anticipated that these solid-state NMR techniques may be also applied to other organic solid state electrolyte materials to achieve a better understanding of their transport mechanisms and molecular dynamics.

Alexis Laforgue - One of the best experts on this subject based on the ideXlab platform.

  • Li4Ti5O12/poly(methyl)thiophene asymmetric hybrid Electrochemical Device
    Journal of Power Sources, 2004
    Co-Authors: Aurelien Du Pasquier, Alexis Laforgue, Patrice Simon
    Abstract:

    Abstract Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid Electrochemical Device with a nano-structured Li4Ti5O12 anode. This Device displays the specific power of a supercapacitor, with a higher specific energy of 10 Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.

  • li4ti5o12 poly methyl thiophene asymmetric hybrid Electrochemical Device
    Journal of Power Sources, 2004
    Co-Authors: Aurelien Du Pasquier, Alexis Laforgue, Patrice Simon
    Abstract:

    Abstract Electrochemically prepared poly(methyl)thiophene is characterized by cyclic voltammetry and galvanometry with an activated carbon counter-electrode. It is then used as a cathode in a laminated plastic asymmetric hybrid Electrochemical Device with a nano-structured Li4Ti5O12 anode. This Device displays the specific power of a supercapacitor, with a higher specific energy of 10 Wh/kg, and better cycle-life than a Li-ion battery. The matching ratio of the active materials was found to strongly influence cycle-life.