Thermodynamic aspects of ion intercalation in KhFek[Fe(CN)6]l*mH2O compounds: application to the Everit's Salt/Prussian blue transition.
The K(+) reversible processes for ion exchange in K(h)Fe(k)[Fe(CN)(6)](l)*mH(2)O host compounds (Prussian Blue) were thermodynamically analyzed. A thermodynamic approach was established and developed based on the consideration of a lattice-gas model where the electronic contribution to the chemical potential is neglected and the ion-host interaction is not considered. The occupation fraction of the intercalation process was calculated from the kinetic parameters obtained through ac-electrogravimetry in a previous paper. In this way, the mass potential transfer function introduces a new way to evaluate the thermodynamic aspect of intercalation. Finally, based on the thermodynamic approach, the energy used to put each K(+) ion into the host material was calculated. The values were shown to be in good agreement with the values obtained through transient techniques, for example, cyclic voltammetry. As a result, this agreement between theory and experimental data validates the thermodynamic approach considered here, and for the first time, the thermodynamic aspects of insertion were considered for mixed valence materials.
Giménez-Romero
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UPR 15 du CNRS, Laboratoire Interfaces et Systèmes Electrochimiques, Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris, France.
Bueno
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García-Jareño
J J
JJ
Gabrielli
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Perrot
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H
Vicente
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