## 4 Conclusions  
In this work, we reported a novel silicon oxycarbide-graphite-tin nanoparticle composite for lithium-ion batteries. Samples were produced using flake graphite and liquid preceramic and tin precursors via an ultrasound-enhanced hydrosilylation reaction. Employing high power probe sonication ensures the homogeneous mixing of all components and accelerates the cross-linking process. Final ternary composites were obtained through pyrolysis, which transformed the preceramic polymer into carbon-rich silicon oxycarbide and tin precursor into the tin nanoparticles via carbothermal reduction. This resulted in homogeneous composites with tin nanoparticles uniformly distributed mainly in the ceramic phase. We observed that during carbothermal reduction of the tin precursor, carbon coming from the free carbon phase and mixed bonds silicon tetrahedra is preferably consumed over graphite. This is related to better mixing of the tin precursor with the preceramic polymer, as well as the high activation energy for the SnO\({}_{2}\)-graphite reaction. In our system, graphite provided appropriate conductivity and softness for stable alloying-dealloying of tin nanoparticles upon multiple cycles and also actively intercalated/deintercalated lithium ions. Replacing part of the ceramic matrix with graphite enabled an increase in the tin content with regard to literature reports, without deteriorating electrochemical stability upon prolonged charge-discharge cycles. Our best performing sample, SiOC:C\({}_{0.2}\)/Sn-60%, delivers a capacity about 100 mAh g\({}^{-1}\) higher than the state-of-the-art SiOC/Sn-40% measured at the same conditions, while the stability at 1C was roughly the same. However, ternary composites are sensitive to high polarization currents (above 1C) because of the graphitic component. **Supplementary Materials:**[72] The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/nano12030410/s1](https://www.mdpi.com/article/10.3390/nano12030410/s1)]([https://www.mdpi.com/article/10.3390/nano12030410/s1](https://www.mdpi.com/article/10.3390/nano12030410/s1)), Table S1. The results of deconvolution of Raman spectra for studied materials; Table S2. The results of deconvolution of Raman spectra for studied materials - continuation; Table S3. BET surface area for obtained composite materials. ; Table S4. Data obtained from XRD according to PDF card Sn-ref_00-004-0673; Figure S1. Raman fitting results for graphite. ; Figure S2. SEM images of SiOC, binary SiOC/Sn and ternary SiOC:C/Sn composites, (a-e) secondary electrons mode, (f-j) backscattering mode. ; Figure S3. SEM images of (a) SiOC/Sn-40%, (b) SiOC:C\({}_{0.2}\)/Sn-40%, and (c) SiOC:C\({}_{0.1}\)/Sn-60% samples. ; Figure S4. The adsorption curves of nitrogen (77 K) for obtained composite materials. ; Figure S5. The size distribution of the Snnanoparticles in the SiOC:C/Sn and SiOC/Sn nanocomposites. SiOC\({}_{\rm Pre}\) content corresponds to the weight percentage content of preceramic polymer in preceramic blend. ; Figure S6. EDX elemental composition of tin-rich (SiOC) and tin-poor (graphite) regions of the SiOC:C\({}_{0.2}\)/Sn-60% sample. ; Figure S7. SEM images of (a) SiOC:C\({}_{0.2}\)/Sn-40% and (b) SiOC:C\({}_{0.1}\)/Sn-60% composites showing accumulation of tin nanoparticles in the ceramic phase. ; Figure S8. Cyclic voltammetry curves of (a) SiOC:C\({}_{0.2}\)/Sn-60%, (b) SiOC:C\({}_{0.1}\)/Sn-60% and c) SiOC:C\({}_{0.2}\)/Sn-40%. ; Figure S9. SEM images of electrode layers before (\"fresh\") and after extended cycling tests (2 cycles at 18.6 mA g-1 followed by 100 cycles at 372 mA g-1) recorded for a) SiOC/Sn-40%, (b) SiOC:C\({}_{0.2}\)/Sn-40% and (c) SiOC:C\({}_{0.2}\)/Sn-60%. ; Figure S10. Diffractograms of the cycled electrodes, Inset: the selected 2 Theta range of the diffractogram of SiOC:C\({}_{0.2}\)/Sn-60% composite. D.K. : Investigation, Formal Analysis, Data Curation, Visualization, Writing--Original Draft, Writing--Review and Editing; P.V.W.S.