Experimental and Modeling of Conductivity for Electrolyte Solution Systems.

Lianying Wu,Weitao Zhang,Yangdong Hu,Xia Chen,Yan Wang

doi:10.1021/acsomega.0c03013

Lianying Wu, Weitao Zhang + Show 3 more

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https://doi.org/10.1021/acsomega.0c03013

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Journal: ACS omega	Publication Date: Aug 24, 2020
Citations: 87	License type: cc-by

Affiliation: Ocean University of China, Qingdao University

Abstract

Studying the concentration and temperature dependence of the conductivity of electrolyte solution is of great significance for the evaluation and improvement of the performance of the electrochemical system. In this paper, based on the influence of the number of free ions and ion mobility on the conductivity, a semiempirical conductivity model with five parameters was proposed to correlate the conductivity, concentration and temperature data of electrolyte solutions at medium and high concentrations. The conductivities of NaCl and CaCl2 in propylene carbonate–H2O binary solvents were measured at temperatures varying from 283.15 to 333.15 K. The validity of the model was verified by the experimental data of this paper and the conductivity, concentration, and temperature data of 28 electrolyte solution systems in the literature. The electrolyte solutions investigated in this paper included binary organic solvent systems, pure organic solvent systems, and aqueous solution systems. The results showed that the proposed model can fit the experimental data well for both pure solvent and mixed solvents systems, which is of great value to practical engineering applications.

Highlights

The ionic conductivity of the electrolyte solution is known as a key parameter to evaluate the performance of the solution, and it has been widely used in the fields of electrochemistry, biochemistry, and environmental chemistry
Studying the concentration and temperature dependence of electrolyte solution conductivity is of great significance to the evaluation and improvement of electrochemical system performance.[4]
Using the MSA transport theory as a basis, Bernard et al extended the conductivity model to mixed solutions, which was further extended to weak electrolyte buffer solution systems, but the accuracy of the model depends on the selection of ion radius.[10−12] In recent years, Yim et al proposed a semiempirical model based on the free volume theory, which gave a good fit over the whole concentration range.[13,14]

Summary

Introduction

The ionic conductivity of the electrolyte solution is known as a key parameter to evaluate the performance of the solution, and it has been widely used in the fields of electrochemistry, biochemistry, and environmental chemistry. Using the MSA (mean spherical approximation) transport theory as a basis, Bernard et al extended the conductivity model to mixed solutions, which was further extended to weak electrolyte buffer solution systems, but the accuracy of the model depends on the selection of ion radius.[10−12] In recent years, Yim et al proposed a semiempirical model based on the free volume theory, which gave a good fit over the whole concentration range.[13,14] Different from theoretical models, the undetermined parameters in an empirical model of the electrical conductivity can be obtained by fitting the experimental data, such as the equation developed by Villullas and Gonzalez,[15] polynomial models,[16] and the Casteel−Amis equation.[17,18] One of the most successful empirical models is the Casteel−Amis model, which contains four parameters and can well fit the experimental data of electrolyte solutions from infinite dilution to saturation

Results

Discussion

Conclusion