Three‐Dimensional Porous Carbon Framework Confined Si@TiO2 Nanoparticles as Anode Material for High‐Capacity Lithium‐Ion Batteries

Abstract Silicon‐based lithium‐ion battery anodes, in recent years, have caught widespread interest seeing their great theoretical capacity, low charge‐discharge potentials, and ample natural storage. However, poor electrochemical performance is typically observed, attributed mainly to significant volume expansion, unstable solid‐electrolyte interphase, and low intrinsic electronic/ionic conductivity. Numerous attempts have been reported to revamp its electrochemical performance, including the capacity cycle stability and cycle life. Herein, we reported the synthesis of three‐dimensional (3D) Si@TiO 2 @C nanohybrids adopting a facile three‐step synthesis strategy. Compared with Si@C and C (derived from polyaniline) electrodes, the well‐designed Si@TiO 2 @C electrode delivered a momentous enhancement in the electrochemical performance thanks to the presence of robust TiO 2 shell and polyaniline‐derived porous carbon skeleton to cope with volume changes of silicon during lithiation and promote the electric conductivity of the overall electrode. The Si@TiO 2 @C hybrid electrode delivered a high initial discharge capacity of 1748.6 mA h g −1 at 100 mA g −1 and a stable reversible capacity of 1112.5 mA h g −1 at 100 mA g −1 after 500 cycles, with the coulomb efficiency of 98.8 %. Moreover, the electrode showed a high reversible capacity of 508.9 mA h g −1 even at 500 mA g −1 at the 500th cycle with the coulomb efficiency of 99.1 %. This work showed the paramount role of TiO 2 shell and 3D porous carbon skeleton, being a promising future for designing the next generation of high capacity, long cycle stable anode materials for lithium‐ion batteries.