Electrolyte solutions for chemical power sources

Abstract

The study of electrolyte solutions and the theory of their structure have been the subject of close attention of researchers over the past two centuries, since they provide conditions for ion transport and the formation of a type of conductivity. The occurrence of ionic conductivity depends on the structure and composition of the electrolyte, which form its physico-chemical and electrochemical properties. Of particular importance is the effect of the nature of the solvent and its interaction with the saline component of the solution. A common physico-chemical property of electrolyte solutions is the degree of dissociation, which determines the formation of a conductive medium. But there are still limitations. The limited understanding of the distribution of electrolytes by the degree of dissociation into strong and weak was discovered at the beginning of systematic studies of ionic processes in non-aqueous solvents (P. Walden, C. Kraus, G. Fuoss, N. A. Izmailov). Indeed, it turned out that many electrolytes that are completely dissociated in water (hydrogen peroxide, nitric and perchloric acid, and many salts) turn out to be weak in non-aqueous solvents, where their behavior falls under the law of acting masses. Thus, the strength of the electrolyte (as a property of dissociating into ions) is also determined by the property of the solvent. Therefore, modern theories divide electrolytes into true (ionophores) and pseudo-electrolytes (ionogens). Ionophores are compounds that already exist in the condensed state in ionic form. These are inorganic salts (NaCl, K2SO4), and organic salts such as N(C2H5)4Pic. Ionogens form (generate) ions only upon contact with a solvent. Ionogens include aqueous solutions of acetic acid, benzoic acid, hydrogen peroxide, and others. Thus, the solvent is an integral component of such an electrolyte, and its chemical and physical properties have a great impact on further changes in the physico-chemical properties of the electrolyte system.