Nanostructured silicon-graphite composites range among the best options for achieving high-energy anodes of lithium-ion batteries. Growing silicon nanowires on graphite produces silicon-rich composites, named Gt-SiNW, with high capacity and stability. We previously demonstrated that, in this composite, silicon distributes homogeneously around the graphite (Figure 1), and the direct contact provides enhanced mechanical stability to the electrode1. However, their cost effective production remains a challenge, since the growth of silicon nanowires requires a metal catalyst, for which gold is the most efficient and common. We now turn to more abundant and lower cost metals, such as tin. As tin metal readily oxidizes in air, we compare tin sulfide and tin oxide2 as sources of tin. We show that both SnS and SnO2 are reduced in situ during the growth process by the vapors of diphenylsilane, used as the source of silicon. Tin enables silicon nanowire growth at lower temperature than with gold, lowering the energy cost. As the oxygen content in the anode active material has a strong impact on lithiation efficiency and SEI formation3, whether the oxygen and sulfur brought by the SnO2 and SnS catalyst incorporate in the composite is an important question. We thus investigate the effect of choosing SnS or SnO2 as a growth catalyst on the composite nanostructure and composition. A quantitative in depth analysis of the composition of the composites by energy dispersive spectroscopy (EDS) allowed to measure accurately the content in oxygen not only in the composite, but also in its graphite and silicon parts. Studying the composition revealed that oxygen from SnO2 seeds is incorporated into the silicon nanowires, corresponding to about 5% in weight in the silicon. By contrast, no sulfur and very little oxygen are detected in the composite from SnS seeds. We show that SnS-seeded Gt-SiNW composites, in which the silicon contains less SiO2, result in an anode material of superior initial Coulombic efficiency and a slightly higher Coulombic efficiency in cycling, while capacity, stability in cycling and rate capability are very similar for the two anode active materials. This small but reproducible improvement is attributable to the lower oxygen content in the anode active material. The silicon content in Gt-SiNW composites were optimized at a content in Si of 25% in weight for a capacity 1000 mAh g-1. At C/5 rate, this composite delivers an areal capacity up to 3.6 mAh cm-2 that increases linearly with the electrode loading (Figure 2a), showing the good electronic conductivity of the electrode. It shows an 82% capacity retention over 200 cycles. In rate capacity tests (Figure 2b), the optimal Gt-SiNW composite shows little capacity fade up to a rate of 2C.