2003 Volume 71 Issue 12 Pages 1052-1054
The individual self-diffusion coefficients of the lithium ion, anion and solvent in the electrolytes for lithium batteries have been measured by the pulsed-gradient spin-echo (PGSE) 7Li, 19F, and 1H NMR, respectively. Based on the classical Stokes-Einstein equation for self-diffusion coefficient, bulk viscosity and Stokes radius of the diffusing species, the solvation effects around the lithium ion in 17 different solvents are discussed from the hydrodynamic diffusing radius of the lithium ion. The normalized anion hydrodynamic sizes of N(SO2CF3)2 (TFSI) and BF4 in GBL and PC are also calculated by using the diffusion coefficients and the van del Waals radius. The self-association of BF4 at concentrated region is discussed.
