Two three-electrode half-cells, termed cells 1 and 2, were made for the validation of the theoretical derivation. The working electrode (⌀13 mm) was a tape-cast composite electrode consisting of 90 wt% NMC811 powder (Customcells Itzehoe GmbH), 5 wt% of carbon black (Super C65, Imerys) and 5 wt% poly(vinylidene difluoride) (PVdF, Solvay), whose fabrication procedure can be found in the previous work. According to the supplier, the NMC811 particles have a median diameter of 4 µm and specific surface area of 1.5 m 2 g -1 , determined by the Brunauer-Emmett-Teller (BET) analysis of the nitrogen adsorption isotherm. The specific volume was calculated from the molecular mass and the previously reported (rhombohedral) unit cell parameters obtained through X-ray diffraction (XRD) to be 0.63056 cm 3 g -1 . The areal loadings of NMC811 were 2.11 and 2.13 mg cm -2 in cells 1 and 2, respectively. Both the counter (⌀15 mm) and reference electrodes (ring with inner and outer diameters of 16 and 22 mm, respectively) were metallic lithium (Cyprus Foote Mineral, 125 μm thick). The reference electrode was placed between the working and counter electrodes with separators (Celgard 2325) on both sides according to a previously reported cell geometry. The cells were assembled in an Ar-filled glove box with 1 M LiPF6 in a mixture of ethylene carbonate/diethylene carbonate (EC/DEC 1:1 by volume, Solvionic, purity: 99.9%) as the electrolyte and sealed in pouch bag material. Assembled cells were rested for 12 hours before 3 pre-cycles at 20 mA g -1 between 3.0 and 4.3 V. Electrochemical tests were carried out using a Biologic MPG 2.