UNUSUAL, NON-COTTRELL BEHAVIOR OF IONIC TRANSPORT IN THIN CELLS AND IN FILMS

Transport of a single-salt MX across thin-layer solid/liquid electrolyte cells and corresponding membranes is treated with consideration of the bulk resistance and the resulting bulk voltage drop. The interfaces are reversible ionic or M/M(+z) character, and X(-z) is blocked. The analysis uses floating boundary conditions but linearizes the nonlinear, implicit equations describing current, voltage, and transport parameters. Bulk resistance causes a major distribution of applied voltage between interfacial and bulk components. Modified Cottrell current-time responses appear, in time-region sequence, with ohmic, normal Cottrell, exponential, and steady-state characteristics. Closely related problems are treated approximately, including impedances, e.g., small-amplitude ac responses, of resistive films with simultaneous dc voltage applied and with simultaneous dc current flow; analysis of passive networks with dc-voltage-dependent circuit elements; and distribution of resistivity across small and large levels of concentration-polarized thin-layer films and cells.