Modeling of Porous Insertion Electrodes with Liquid Electrolyte

The dynamics of porous insertion electrodes during charge or discharge is described by a simplified mathematical model, accounting for the coupled transport in electrode and electrolyte phases. A numerical method to evaluate the response of this model to either controlled potential or controlled current is outlined, and numerical results for the discharge of a porous TiS/sub 2/ electrode in an idealized organic electrolyte are presented. It is demonstrated how electrolyte depletion is the principal limiting factor in the capacity obtained during discharge of this electrode system. This depletion is a consequence of the mobility of the ions not inserted, therefore the performance or this type of electrode is optimized by choosing electrolytes with transport number as close to unity as possible for the inserted ion. 23 refs.