Association constants in solutions of lithium salts in butyrolactone and a mixture of propylene carbonate with 1,2-dimethoxyethane (1 : 1), according to conductometric data

Abstract

A conductometric study is performed with solutions of lithium bis(oxalato)borate (LiBOB) in γ-butyrolactone (γ-BL) at 278.15–388.15 K and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), LiBOB, and lithium tetrafluoroborate (LiBF₄) in mixtures of propylene carbonate and 1,2-dimethoxyethane (PC + 1,2-DME) (1 : 1) at 278.15–348.15 K. Limiting molar electrical conductivities (LMECs) and association constants (Ka) in the studied solutions of electrolytes are determined using the Lee–Wheaton equation. The effect temperature, the nature of the solvent, and the properties of the anion have on the conductivity and interparticle interactions in solutions of lithium salts in γ-BL and PC + 1,2-DME (1 : 1) is established. It was concluded that the studied solutions are characterized by low values of their association constants. It was found that the ВОВ^– anion destroys the structure of the solvent.The thickness of the dynamic solvation shell of ions (ΔR) remains constant for both solvents over the studied range of temperatures, and ΔR is significantly greater for Li⁺ than for other ions.