A novel electrochemical method for measuring salt diffusion coefficients and ion transference numbers

We have found it possible to determine salt diffusion coefficients and ion transference numbers by obtaining, respectively, the steady-state ion-transport-limited current at a microdisk electrode in spherical diffusion geometry and the transient ion-transport-limited current at a macrodisk electrode in planar diffusion geometry in ionic solutions containing no supporting electrolyte. The method is demonstrated in aqueous solutions of AgNO sub(3) and in propylene carbonate solutions of LiClO sub(4). The ion transport parameters obtained agree well with those reported previously. It would appear that the method also could be used in the study of ion transport in solid electrolytes.