Furthermore, solid-state cells show significantly lower Coulomb efficiencies in the first cycle with values between 77% and 82% in the solid-state, compared to ≈90% in the liquid electrolyte based cells. Low first cycle efficiencies are common in other solidstate battery chemistries, e.g., using Li(Ni,Co,Mn)O2 as active material and generally, they are related to contact losses between the active material and the SE due to volumetric expansion as well as the formation of a SE-CAM interphase (CEI). The capacity retentions reflect the low initial efficiency in the first cycle, with gradual capacity losses afterwards (Figure ). The capacity retentions are comparable in general, but cathodes with the highest ΦCAM show a lower overall capacity retention of 73% (average Coulomb efficiency of 98.3%) compared to 85% (average Coulomb efficiency of 99.5%) for cathodes with the lowest ΦCAM after 40 cycles. Given the special role of the first charge cycle, these relative retentions and average efficiencies are referring to or count from the second charge onward. In addition to the capacity retention with ongoing cycling, the rate capability was tested for exemplary compositions of ΦCAM = 0.32, 0.51 and 0.74 (Figure ). In agreement with the constant C-rate cycling, no strong compositional trends can be observed in the rate retention upon first visual inspection of the data.