A TiO₂/SiO_x/Si composite derived from cellulosic cotton as the structural template was biomimetically synthesized. Modified sol–gel deposition processes were performed to coat each cellulose nanofiber with a SiO₂ thin gel layer, followed by layer-by-layer self-assembly processes to form an external TiO₂ coating with controllable thickness. The resulted matter was calcined in air to obtain the TiO₂/SiO₂ composite, which was successively put in N₂ atmosphere and treated with magnesiothermic reduction reaction, resulting in the final TiO₂/SiO_x/Si composite. The composite possessed a typical hierarchical three-dimensional (3D) nanotubular network microstructure precisely inherited from the cellulosic cotton template, and each nanotube had a core-shell nanostructure with Si-based matters as the core and TiO₂ coating as the shell. Compared with the bare nanotubular SiO_x/Si material, the TiO₂/SiO_x/Si composite showed a highly enhanced electrochemical performance as an anode material for lithium-ion batteries (LIBs), delivering an initial discharge capacity of 2370 mAh g⁻¹ at a current density of 0.2 A g⁻¹ (an initial Coulombic efficiency of 56.4%), a reversible capacity of 682 mAh g⁻¹ after 100 discharge/charge cycles, and a discharge capacity of 241 mAh g⁻¹ at a high current density of 2.0 A g⁻¹. The excellent specific capacity, cycling stability and rate capability are ascribed to the synergistic effect of the unique 3D porous nanotubular network structure and the uniform TiO₂ coating layer, which accommodates the volume variation of Si-based components during cycling, offers sufficient ion transport pathways and improves the electron transfer efficiency. This work provides a facile biomass-based strategy for fabrication of metal oxide/Si composites with well-defined microstructures that exhibit significant potential as anode materials for LIBs.

仿生合成了以纤维素棉为结构模板的TiO ₂ / SiO _x / Si复合材料。进行了改良的溶胶-凝胶沉积工艺，在每根纤维素纳米纤维上涂覆了SiO ₂薄凝胶层，然后进行逐层自组装工艺，以形成厚度可控的外部TiO ₂涂层。将所得物质在空气中煅烧以获得TiO ₂ / SiO ₂复合材料，将其依次置于N ₂气氛中并用镁热还原反应处理，得到最终的TiO ₂ / SiO _x/ Si复合材料。该复合材料具有典型地从纤维素棉模板继承而来的三维三维（3D）纳米管网络微观结构，并且每个纳米管均具有核-壳纳米结构，其中硅基物质为核，TiO ₂涂层为壳。与裸露的纳米管SiO _x / Si材料相比，TiO ₂ / SiO _x / Si复合材料作为锂离子电池（LIBs）的负极材料具有更高的电化学性能，初始放电容量为2370 mAh g ^-1在0.2 A g ^-1的电流密度（初始库仑效率为56.4％）下，可逆容量为682 mAh g ^-1在100次放电/充电循环之后，在2.0A g ^-1的高电流密度下的放电容量为241mAh g ^-1。优异的比容量，循环稳定性和速率能力归因于独特的3D多孔纳米管网络结构和均匀的TiO ₂涂层的协同效应，该涂层可适应循环过程中基于Si的组分的体积变化，并提供足够的离子传输路径并提高了电子转移效率。这项工作为制造具有明确定义的微结构的金属氧化物/硅复合材料提供了一种基于生物质的简便策略，该复合材料具有显着的潜力，可作为LIB的阳极材料。