The initial cathode utilization is related to the transport given that it is a measure of the contacted and electrochemical active CAM in the composite, i.e., how accessible and at which rate active material particles are for both charge carriers. In the following, the initial cathode utilization is measured by the average capacity per gram CAM QCAM. The average includes both, the average over the first five cycles (excluding first charge) of each individual cell, and the average and standard deviation of all cells investigated with the same composition. Porous electrode theory can guide the understanding of these trends given that it aims to describes the reaction rate distribution throughout the cathode, as quantified by the δ-parameter (Eq. 4, Figure ). With that, the δ-parameter (Eq. 4, Figure ) should be This is the case for all composites in the range of ΦCAM = 0.32 to 0.74 at 0.134 C and with thicknesses between 85 μm and 73 μm (Figure , right). For these cells, the δparameter ranges between 0.3 and 2.8 (Figure ). Consequently, the δ-parameter analysis predicts high uniformity of the reaction rate distribution and gives a rational for the marginal changes in cathode utilization. Increasing the cathode thickness and, considering constant C-rates, the applied current density, increases the value of δ from 2.8 to 6.3 and 11.1, moving away from the desired condition of δ ≲ 1 and explaining the decrease of the cathode utilization going to a thick electrode configuration. For the edge case of pure Li2FeS2 as cathode, the δ-parameter significantly increases to ≈300