Condensed Matter Physics, 2011, vol. 14, No. 4, p. 43801:1-6
DOI:10.5488/CMP.14.43801           arXiv:1202.4843

Title: Application of the SRISM approach to the study of the capacitance of the double layer of a high density primitive model electrolyte
  S. Woelki (Institute of Physical and Theoretical Chemistry, University of Regensburg, Germany) ,
  D. Henderson (Department of Chemistry and Biochemistry, Brigham Young University, Provo UT 84602, USA)

In this study the Singlet Reference Interaction Site Model (SRISM) is employed to the study of the electrode charge dependence of the capacitance of a planar electric double layer using the primitive model of the double layer for a high density electrolyte that mimics an ionic liquid. The ions are represented by charged hard spheres and the electrode is a uniformly charged flat surface. The capacitance of this model fluid is calculated with the SRISM approach with closures based on the hypernetted chain (HNC) and Kovalenko-Hirata (KH) closures and compared with simulations. As long as the magnitude of the electrode charge is not too great, the HNC closure shows the most promise. The KH results are reasonably good for a high density electrolyte but are poor when applied at low densities.

Key words: singlet integral equations, ionic liquid, restricted primitive model, capacitance
PACS: 82.45.Fk, 61.20Qg, 82.45.Gj

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