## 3 Results and Discussion
The morphology of the electrode layers of the composites with a lower number of tin nanoparticles (SiOC/Sn-40% and SiOC:C\({}_{0.2}\)/Sn-40%) does not change after extended cycling tests (Figure S9a,b), whereas the SiOC:C\({}_{0.2}\)/Sn-60%) exhibit some cracks (Figure S9c, which may be attributed to the higher Sn concentration and associated volume changes upon alloying as the tin nanoparticles are accumulated mainly on the ceramic part. The XRD analysis of cycled samples are presented in Figure S10 (in Supplementary Materials). The diffractograms are quite complex and reveal the presence of graphite, \(\beta\)-Sn (components of the composites), Li\({}_{2}\)CO\({}_{3}\), Sn\({}_{3}\)O\({}_{4}\) (components typical for SEI on tin containing electrodes) [65; 66; 67], Li\({}_{2}\)Sn\({}_{5}\) (one of the lowest lithiation states of Li-Sn alloys), and Cu (current collector). The XRD patterns of the cycled binary and ternary composites are similar. A quantitative analysis would be ambiguous because of the overlapping of the XRD reflexes and strong peaks coming from the copper current collector. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Material**} & **1 st Cycle** & **1 st Cycle** & \multirow{2}{*}{**\(\eta\) (0.005 V–1.5 V)/\%**} & \multirow{2}{*}{**\(\eta\) (0.005 V–3 V) /\%**} \\  & **C\({}_{\text{irve}}\)/mAh g\({}^{-1}\)** & & & \\ \hline SiOC:C\({}_{0.2}\)/Sn-40\% & 600 & 439 & 42 & 56.5 \\ SiOC:C\({}_{0.2}\)/Sn-60\% & 623 & 507 & 45 & 62 \\ SiOC:C\({}_{0.1}\)/Sn-60\% & 625 & 515 & 45 & 63 \\ SiOC/Sn-40\% & 699 & 572 & 45 & 65 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Selected electrochemical results. Coulombic efficiencies \(\eta\) within 0.005 V–1.5 V and 0.005 V–3 V potential regions were calculated by dividing the first lithiation capacity by the first delithiation capacity obtained in certain potential regions. Figure 9: (**a**) Cycling stability at 372 mA g\({}^{-1}\) and the corresponding Coulombic efficiencies; (**b**) rate capability of the ternary SiOC/C/Sn composites. To give some overview, we compared our ternary composites to the state-of-the-art SiOC/Sn-40%, which was reported as the best performing SiOC/Sn composite [13]. The capacity of SiOC/Sn-40% is around 520 mAh g\({}^{-1}\) with a stability of 90.1% over 100 cycles. It appears that the capacity of SiOC/Sn-40% is lower than the capacity of the SiOC:C\({}_{0.2}\)/Sn-60% sample but higher than that of SiOC:C\({}_{0.2}\)/Sn-40%, while the stability is similar to the stability of these samples. These results indicate that the capacity strongly depends on the composition in a way that the presence of tin increases the capacity of composites, while graphite decreases it, which can be expected taking into account their theoretical capacity values. However, graphite can be a good component improving the ability of the host matrix to host higher tin content, which in turn can help increase the overall capacity of a ternary composite compared to the binary one. The rate capability measurements within the 5 mV-1.5 V potential range are presented in Figure 9b. At lower current rates (C/5 and C/2 in respect to graphite) the SiOC:C\({}_{0.2}\)/Sn-60% composite exhibits the highest capacity values. However, with increasing polarization currents (above 1C-372 mA g\({}^{-1}\)) capacity values of all the ternary composites decrease more rapidly than for the binary SiOC/Sn-40% composite. Moreover, after returning to the low polarization currents, the capacities of the ternary composite do not increase as in the case of the binary composite. These results show that the composites with graphite are sensitive to high currents. The pure graphitic electrode also exhibits capacity fading at currents higher than 1C due to uneven SEI formation and lithium plating [68; 69]. On the other hand, SiOC ceramics are known as stable materials at high current rates [24; 70; 71].