## 5 Conclusions  
NMC 622 cathodes were assembled versus lithium using coin cell design. The influence of film thickness and laser structuring pattern on rate capability, as well as the diffusion coefficient of lithium-ions in electrodes were investigated. Galvanostatic measurements and cyclic voltammetry were applied to study the discharge capacity and energy density of the cells with structured and unstructured cathodes. An ultrafast laser with a wavelength of 1030 nm was used to generate line patterns down to the current collector in cathodes with film thicknesses of 91 \(\upmu\)m to 250 \(\upmu\)m. The pitch distance of line pattern was varied from 200 \(\upmu\)m to 600 \(\upmu\)m. Despite the mass loss due to the laser ablation of electrode material during laser processing, the cells containing structured cathodes with 200 \(\upmu\)m pitch distance showed great improvement in specific capacity with discharge rates from C/2 to 3C. Comparing that to a cell with unstructured cathode, an increase of energy density from 50% to 300% was observed in galvanostatic measurements. At higher discharge rates of above 2C, the cells with 91 \(\upmu\)m cathodes showed better electrochemical performance in terms of the volumetric energy density compared to cells with thicker cathode. Besides, volumetric energy density can be improved by increasing the electrode thickness at low C-rates (C/10 and C/5), due to a decrease of Al foil fraction inside the cathode. The increased surface area after laser processing provides new lithium diffusion pathways, which guarantees a high discharge capacity at elevated C-rates. However, a deterioration of energy density with increasing cathode thickness and increasing discharge rate was observed, which is due to the increase of internal resistance and the damage of the mechanical integrity of thick cathode material. Besides, the qualities of NMC 622 powder, such as particle sizes and purity, have impacts on the electrochemical performance, which were observed in the ongoing study using NMC 622 powder from another supplier. Cyclic voltammetry verifies that the chemical diffusion coefficient of lithium-ions in NMC 622 electrode decreases with increasing electrode film thickness. However, the diffusion coefficients of lithium-ions in structured and unstructured cathodes were almost the same. To explain the improved rate capability of structured cathodes, the expansion of the electrode's surface must be taken into account. With line pattern, up to 400% surface expansion is applied to cathode, resulting in new diffusion paths for lithium-ions. The Ragone chart reveals a trade-off between power and energy for NMC 622 cathodes, and laser structuring shows an improvement of energy at higher power. Besides, the production cost of cells could be reduced, since less cathode sheets and other inactive components, such as separators and current collectors, are required for a 52-Ah automobile pouch cell with increasing electrode film thickness. Therefore, proper film thickness and laser structuring pattern should be selected related to the specific application-oriented demand. Thick electrodes (> 200 \(\upmu\)m) without laser structuring are suitable for applications such as energy storage at low discharge rates of C/10 and C/5. While structured electrodes with thicknesses below 100 \(\upmu\)m are more suitable for high-power (\(\geq\) 1000 W/L). Meanwhile, the combination of laser structuringand thick film electrode has potential in the automobile industry, where high power and high energy are simultaneously required. Conceptualization, P.Z. and W.P. ; methodology, P.Z. ; validation, H.J.S. and W.P. ; investigation, P.Z. ; resources, H.J.S. and W.P. ; data curation, P.Z. ; writing--original draft preparation, P.Z. ; writing--review and editing, P.Z. and W.P. ; supervision, W.P. This research was funded by German Research Foundation (DFG), project No. 392322200. We are grateful to our colleagues [PERSON], [PERSON], and [PERSON] for their technical assistance and support with material and battery analyses.