Ion solvation in lithium battery electrolyte solutions Part II. Solvent effects on lithium-ion intercalation in niobium triselenide

Abstract

Solvent effects on the intercalation of lithium ions in niobium triselenide electrodes have been investigated by cathodic polarization measurements in propylene carbonate (PC), acetonitrile (AN), 1,2-dimethoxyethane (DME), tetrahydrofuran (THF) and their 50% vol./vol. mixtures with PC, using 1 M LiClO 4 as the supporting electrolyte. The polarization follows the general order PC≈PC/AN≈PC/THF>THF>PC/DME>DME>AN which reflects the probable size of the solvated lithium ion. This suggests that intercalation of Li + into the host lattice occurs without desolvation. Lattice diffusion coefficients of Li + in NbSe 3 in the various solvents have been determined by an intermittent galvanostatic technique and found to be in the order AN>DME≈PC/DME>PC/AN>PC. This has also been explained in terms of solvation effects and the composition of the resultant Li + solvation shell.