Watermelon‐Like Structured SiO<i>_x</i>–TiO₂@C Nanocomposite as a High‐Performance Lithium‐Ion Battery Anode

Abstract

Abstract A unique watermelon‐like structured SiO x –TiO 2 @C nanocomposite is synthesized by a scalable sol–gel method combined with carbon coating process. Ultrafine TiO 2 nanocrystals are uniformly embedded inside SiO x particles, forming SiO x –TiO 2 dual‐phase cores, which are coated with outer carbon shells. The incorporation of TiO 2 component can effectively enhance the electronic and lithium ionic conductivities inside the SiO x 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 SiO x –TiO 2 @C nanocomposite to have excellent electrochemical performances, including high specific capacity, excellent rate capability, and stable long‐term cycleability. A stable specific capacity of ≈910 mAh g −1 is achieved after 200 cycles at the current density of 0.1 A g −1 and ≈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.