Anomalous temperature dependence of the differential capacitance in valence asymmetric electrolytes. Comparison of Monte Carlo simulation results and the field theoretical approach

Abstract

In this paper, we consider the anomalous behaviour of the differential capacitance as a function of the reduced temperature for the case of valence asymmetric systems. Monte Carlo simulation results of these systems are discussed in view of the predictions of a field theoretical approach. We show that a simple field theory for point ions is sufficient to capture the main features of the phenomenon. In particular, the existence of scaling of the curves related to ionic strength is discussed as well as the increase of the differential capacitance peak as a function of the asymmetry between ions. This indicates that important features of the phenomenon are essentially related to the electrical properties of the system.

Keywords:

• Differential capacitance
• Anomalous temperature dependence
• Valence asymmetric electrolytes

Acknowledgements

M. Holovko and D. di Caprio are grateful for the support of the National Academy of Science of the Ukraine (NASU) and the Centre National de la Recherche Scientifique (CNRS) in the framework of project No. 18964. M. Valiskó, D. Boda and D. di Caprio are grateful for the support of the Hungarian Academy of Science and the CNRS in the framework of project No. 18983.