The Use of UV/vis Absorption to Measure Diffusion Coefficients in LiPF[sub 6] Electrolytic Solutions

This work describes the measurement of the diffusion coefficient in lithium-battery electrolytic solutions. We have adapted the method of restricted diffusion to measure diffusion coefficients of in various solvents using ultraviolet/visible (UV/vis) absorption. The use of UV/vis absorption provides a simple alternative to more arduous experiments and reduces the potential for experimental error due to side reactions. The diffusion coefficient was seen to decrease with concentration according to the following: for in acetonitrile and for in ethylene carbonate/diethyl carbonate (with in and in mol/L). This technique may be useful for any liquid solution with a UV-active species of greater than .