In this study, our objective was to deepen the understanding of the correlation between the microstructure and ionic/electronic conductivity of the composite cathode with the cell performance. For this purpose, a conductive matrix (CM) composed of synthesized Li6PS5Cl with minimal CA content was developed by determining the electronic percolation threshold. The effective ionic and electronic conductivity of the CC was measured by EIS in different blocking conditions and balanced by adjusting the phase fractions. It is shown, that the best C-rate capability is in the range of balanced electronic and ionic conductivity with 70.0 % NMC, 28.2 % Li6PS5Cl and 1.2 % C65. Here, creating enough electronic conductive pathways is crucial for passivation coated NMC. When the AM content is increased, simultaneously, C65 content can be minimized to balance the σion & σel with the positive effect of reduced degradation. In addition, adjusting the particle size of the solid electrolyte proves to be an effective way to increase σion of the composite cathode. The residual porosity and interface contacts were addressed by employing different densification techniques (such as cold isostatic pressing). In uniaxial pressing (UP), even when the compaction pressure is increased from 375 to 500 MPa, there is a threshold value for the relative density (RD) ≤ 80.0 %. When cold isostatic pressing (CIP) is applied after UP, the RD can be further increased by approx. 4.5 %. Furthermore, the CC microstructures were analysed via scanning electron microscope (SEM), X-ray microscope (XRM) and FIB-tomography. Subsequently, these findings were correlated with the rate capability and cycling performance of the ASSBs. The results of this study will provide guidelines to effectively design CC microstructures for improved cell performance.