Synergistic effects from super-small sized TiO ₂ and SiO _x nanoparticles within TiO ₂ /SiO _x /carbon nanohybrid lithium-ion battery anode

TiO ₂ /SiO _x /carbon nanohybrid consisting of super-small sized TiO ₂ and SiO _x nanoparticles is in situ formed within the in situ formed carbon matrix using difunctional methacrylate monomers as solvent and carbon source. The relative composition of TiO ₂ and SiO _x is systematically tuned by varying the feeding mass ratio of the precursors (TEOS/TTIP) and HF etching treatment after the carbonization process. The super-small sized TiO ₂ and SiO _x nanoparticles are well intermixed with each other and homogeneously dispersed throughout the carbon matrix, where a good control over crystallinity, morphology, and microstructure of the nanohybrids is achieved. Synergistic effects are demonstrated from both TiO ₂ and SiO _x regarding the increased reversible capacity from the SiO _x phase and maintenance of good cyclic stability by the TiO ₂ component when being used in lithium-ion batteries. A good balance is achieved in terms of reversible capacity, capacity retention, and rate performance in the TiO ₂ /SiO ₂ /C nanohybrid prepared with the TEOS/TTIP mass ratio of 1.0. The reversible capacities are improved by around two times compared to the SiO _x free sample with a good capacity retention of 78 %, which exhibits good rate capability at the current densities up to 3350 mA g ⁻¹ as well.