Carbon-coated SiOx/TiO2 composite nanospheres with conductive TiO2 nanocrystals as anode materials for lithium-ion batteries

The ultrafine TiO 2 nanoparticles are encapsulated in SiO 2 nanospheres by StÖber method to form (SiO x /TiO 2 )@CN composite combined with TiO 2 crystalline transformation and carbon coating process. TiO 2 nanocrystals uniformly embedded in SiO 2 nanospheres to construct a conductivity network that accelerates lithium-ions diffusion, broadens the activation range, and releases the compressive stress induced by volume change. The uniform incorporation of nitrogen elements in the homogeneous surface carbon layer can further enhance the electrical conductivity of the composite. The synergistic combination of the above advantages can work together to endow (SiO x /TiO 2 )@CN with outstanding structural stability, high specific cycle capacity and excellent rate performance. The mass discharge capacity of M5@CN is stable at 547 mA h g − 1 after 500 cycles at 1.0 A g − 1 . The specific capacities of mass discharge at 0.2, 0.5, 1.0, 2.0, and 5.0 A g − 1 are 604, 577, 496, 375, 216 mA h g − 1 , respectively. This research provides a significant reference point for future modifications of SiO 2 -based anode materials.