Interestingly, the charging process is significantly delayed in the initial cycle of SSB-NCA (Fig. ). At about 3 V a sloping region occurs, similar to what has been reported previously . During the beginning of the charging process, the lattice parameters a and c remained almost the same while the rapid non-linear change in lattice parameters were observed as the charging process continued. The time dependence of the lattice parameter points to a growing SEI layer, since as the thickness of the SEI increases the polarization follows, hence, the accessible capacity and correspondingly the changes in lattice parameter decreases. Although no phases (Fig. ) other than NCA and LPSCl have been observed by XRD (potentially related to the detection limit), the degradation of LPSCl and the formation of passivating interphases is evident from XPS and SEM analysis. As shown in Fig. , cathode particles are compactly embedded in the LPSCl matrix. The situation changes after 200 cycles when NCA secondary particles were fractured and dispersed into the LPSCl matrix with significant contact loss (Fig. ). Moreover, LPSCl particles alter their shape from roundish to needle structure (Fig. and Fig. ) and significant changes in chemistry takes place (Fig. ). For LPSCl powder the S 2p spectrum shows two doublets. The main one at 161.4 (S 2p3/2) is related to PS4 3-. A minor second doublet appears at 160.1 eV (S 2p3/2) . It corresponds to S 2-, which originates from the Li2S precursor . In the corresponding P 2p spectrum, a single doublet at 131.7 eV (P 2p3/2) appears, which can be assigned to the PS4 3-compounds . In cycled SSB-NCA a significant amount of new peaks appear at binding energies beyond 166.0 eV in the S 2p spectrum, suggesting the formation of oxygenated sulfur (SOx) compound , and at 163.5 eV, related to bridging sulfur (P-[S]x-P) . The P 2p spectrum presents new components at 133.1 eV and 134.5 eV, related to the formation of P2Sx (polysulfides) and POx , respectively. Additional peaks indicate the presence of other, potentially more complex, compounds. The formation of interphases also contributes to the physical separation of the individual components, due to morphological changes (Fig. ) . Moreover, we hypothesize that non-linearity of the lattice parameter curve is related to the heterogeneity of the formed SEI, which is also evident from observations made by SEM. This heterogeneity causes a non-uniform current distribution around the NCA particles, which potentially further leads to current hotspots. Due to kinetic limitations in the NCA, these hot spots cause local over-charging that leads to high-stress states and ultimately causing fracturing of the cathode particles and void formation (Fig. , j and Fig. ) . This fracturing into partially electronic disconnected primary particles and voids results in a lower accessible capacity and subsequently in a higher effective current experienced by NCA particles, which leads, as a consequence, to a further lowering in accessible capacity . The lower accessibility is also evident by the overall change in lattice parameters as shown in Fig. (compared to LIC@NCA in Fig. ). Nevertheless, in the subsequent cycles, the lattice parameter changes from an approximately exponential decay to a linear behavior (see Fig. ), suggesting that the formation of SEI is kinetically limiting.