Yin L, Huang Y, Chen H, Yan T. A mean-field theory on the differential capacitance of asymmetric ionic liquid electrolytes. II. Accounts of ionic interactions.
Phys Chem Chem Phys 2018;
20:17606-17614. [PMID:
29915842 DOI:
10.1039/c8cp02943a]
[Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A size-asymmetric mean-field theory with ionic interactions is developed for the electric double layer of room temperature ionic liquid (IL) electrolytes, based on the previous work on non-interacting ions (Y. Han et al., J. Phys.: Condens. Matter, 2014, 26, 284103). By solving the modified Poisson-Boltzmann equation with some simplified assumptions following a recent work (Z. A. H. Goodwin et al., Electrochim. Acta, 2017, 225, 190-197), an analytical expression of differential capacitance can be derived, with a scaled electrode potential due to the ionic interactions. Compared with non-interacting ions, the main effect of ionic interactions is the insufficient screening of the electrode potential, and this depresses the differential capacitance compared with the non-interactive case.
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