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Electrochemical Investigations of Polyethylene Glycol‐Based “Soggy Sand” Electrolytes – From the Local Mechanism to the Overall Conduction
Author(s) -
Jarosik Anna,
Pfaffenhuber Christian,
Bunde Armin,
Maier Joachim
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201100351
Subject(s) - materials science , electrolyte , conductivity , thermal conduction , percolation (cognitive psychology) , electrochemistry , chemical engineering , zeta potential , dispersion (optics) , composite material , nanoparticle , nanotechnology , electrode , chemistry , engineering , biology , physics , optics , neuroscience
Using the example of SiO 2 dispersions in LiClO 4 /polyethylene glycol electrolytes, the conduction mechanism of “soggy sand” electrolytes is discussed. The study is essentially based on zeta potential, impedance and transference number measurements as well as on modeling. All the results can be explained by anion adsorption by the oxide particles and increased concentration of free Li + in the double layer. The initially colloidal dispersion quickly forms fractal networks by cluster–cluster aggregation. Once they percolate, an interfacially dominated Li + conductance is observed. The subsequent coarsening of the network is self‐decelerating leading to a steady state conductivity that is, for low volume fractions, enhanced compared to SiO 2 free electrolytes. At higher values, blocking and inhomogeneity effects (e.g., salt trapping) lead to decreased values of the overall conductivity.