Ti-Oxide Doping Alleviated Defects and Introduced Ti–O–Si Bonds to Enhance the Cycling Stability of the Silicon‑Carbon Anode

Silicon-based anode materials have low electrical conductivity, volume expansion and the easy repeated formation of solid electrolyte interface layers, which seriously impede their commercialization. Introducing Ti–O–Si bonds into silicon-based materials has been proven to be an effective way to alleviate silicon defects. Here, we adopted a one-step mechanical force strategy to synthesize Ti–O–Si bonds, and high-energy ball milling was employed to promote the exfoliation of the lamellar structure of natural graphite spherical tailings and restructure it. During the process, nano-Si and Ti 4 O 7 were wound to form spherical particles. Nano-Si particles could not only be in situ immobilized within spherical matrices but also form Ti–O–Si bonds, thereby enhancing interface stability and reducing the formation of lithium dendrites. Due to the rational design of the components and structure, the stress concentration problem caused by the expansion of silicon material during charging and discharging has been alleviated. Si@C@Ti 4 O 7 anode exhibited a long cycle life (after 300 cycles at 0.5 A g −1 , 538.2 mAh g −1 ) and excellent ionic diffusion capability. This work demonstrated the feasibility of introducing Ti–O–Si bonds in a solid phase environment, offering a novel solution for optimizing the silicon-carbon interface and enhancing the high value utilization of natural graphite spherical tailings.