Modeling of Porous Insertion Electrodes with Liquid Electrolyte

The dynamics of porous insertion electrodes during charge or discharge is described by a simplified mathematicalmodel, accounting for the coupled transport in electrode and electrolyte phases. A numerical method to evaluate theresponse of this model to either controlled potential or controlled current is outlined, and numerical results for thedischarge of a porous TiS2-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. Thisdepletion is a consequence of the mobility of the ions not inserted, hence the performance of this type of electrode isoptimized by choosing electrolytes with transport number as close to unity as possible for the inserted ion.