where I is the applied current (in mA) and Qexp(I) (in units of mAh) is the experimentally achieved capacity at that current. Thereby, this definition of rate differs from the definition of the C-rate by relating the current to a practical rather than a theoretical capacity. With that, the inverse of the practical rate directly represents the time in which the charge was acquired. 41 The cathode utilizations as a function of the practical rate are shown in Figure . At the highest applied current density, cathodes with ΦCAM = 0.32 and 0.74 and comparable thickness achieve similar capacities of 55 mAh•g -1 and 51 mAh•g -1 , respectively. Nonetheless, this capacity is achieved at a significantly higher practical rate of 14.9 h Applying this model, Eq. 7 describes the rate performance of the investigated cathodes (dashed lines in Figure ). Moreover, the resulting parameters τ and n confirm the initial hypothesis from visual inspection with both showing a detrimental linear increase with the areal loading of the cathode (Figure ). To understand this observation, we again consider the δ-parameter introduced in the porous electrode theory. While at a rate of 0.134 C, the δ-parameter was close to unity for most of the investigated cathodes, indicating uniform reaction rates and explaining the good cathode utilization even at high CAM volume fractions (Figure ), the average δ-parameter over the investigated current density range δavg is significantly increased. At a composition of ΦCAM = 0.32 this translates to δavg = 3, while for the highest CAM volume fraction and thickness this value is increased to δavg = 22. This significant increase of δavg with increase of ΦCAM and the cathode thickness indicates that nonuniformity of the reaction rate distribution, measured by δavg, can occur as consequence of applying higher current densities. In fact, the parameters τ and n quantifying the rate capability increase linearly as a function of δavg (Figure ) corroborating this hypothesis.