DISCHARGE PERFORMANCE OF COMPOSITE INSERTION ELECTRODES ANALYSIS OF DISCHARGES OF 50 VOL PERCENT LI3N TIS2 ELECTRODES/

The dynamic properties of composite insertion electrodes, i.e., mixed- phase electrodes with solid electrolyte and insertion electrode materi al, have been studied by modelling and experimental investigations. Th e developed models describe the coupled transport of chemical diffusio n in the insertion phase, ionic migration in the electrolyte phase and charge transfer between the two phases. Experimental investigations w ere performed on a 50 v/o Li3N/TiS2 composite electrode. Constant curr ent discharge curves were analysed by comparing with calculations base d on the models. In agreement with theory, the discharge curves vary w ith the square root of time in the beginning of discharge and thereaft er directly proportional to time. However, the linear regions were too short. This seems to be caused by a slow transport of lithium in LixT iS2 at high lithium concentrations.