Abstract The effect of the geometrical parameters of interdigitated batteries, including the number, thickness and the length of the digits, on the delivered battery capacity was investigated in order to optimize battery performance. This optimization was carried out in two dimensions maintaining the area of the different components constant and based on the Doyle/Fuller/Newman theoretical model that describes the electrochemical and ionic transport processes within separator and electrodes. It is observed that the delivered capacity of the battery increases with increasing number of digits as well as by increasing the thickness and the length of the digits, which is related to the smaller path for lithium ion movement during the intercalation/deintercalation processes. Thus, an optimized interdigitated geometry with eight digits shows a delivered capacity of 323 Ah·m − 2 at 350 °C in comparison with 0.7 Ah·m − 2 for a conventional geometry.