Watermelon-Like Structured SiOx-TiO2@C Nanocomposite as a High-Performance Lithium-Ion Battery Anode

A unique watermelon-like structured SiOx-TiO2@C nanocomposite is synthesized by a scalable sol-gel method combined with carbon coating process. Ultrafine TiO2 nanocrystals are uniformly embedded inside SiOx particles, forming SiOx-TiO2 dual-phase cores, which are coated with outer carbon shells. The incorporation of TiO2 component can effectively enhance the electronic and lithium ionic conductivities inside the SiOx particles, release the structure stress caused by alloying/dealloying of Si component and maximize the capacity utilization by modifying the Si-O bond feature and decreasing the O/Si ratio (x-value). The synergetic combination of these advantages enables the synthesized SiOx-TiO2@C nanocomposite to have excellent electrochemical performances, including high specific capacity, excellent rate capability, and stable long-term cycleability. A stable specific capacity of approximate to 910 mAh g(-1) is achieved after 200 cycles at the current density of 0.1 A g(-1) and approximate to 700 mAh g(-1) at 1 A g(-1) for over 600 cycles. These results suggest a great promise of the proposed particle architecture, which may have potential applications in the improvement of various energy storage materials.