Core‐Shell Structured Bi‐Amorphous SiO 2 @TiO 2 Composite for Lithium‐Ion Batteries Anode Material with Ultra‐Stable Performance

Abstract Surface coating strategies have shown to be effective for improving the cyclability of SiO 2 anode materials of lithium‐ion batteries (LIBs). Herein, we prepared commercially amorphous SiO 2 nanoparticles encapsulated in amorphous titanium oxide shells (a‐TiO 2 ) (SiO 2 @a‐TiO 2 ) by a facile hydrolysis of titanium isopropylate in alkaline alcohol system. The elastic a‐TiO 2 shell can mitigate the volume change of amorphous SiO 2 in the lithiation/delithiation processes and improve the electrical conductivity of SiO 2 ‐based anodes. By delicately optimizing the a‐TiO 2 shell (12.18 wt.%), SiO 2 @a‐TiO 2 composite delivers a superior cycling capacity of 647 mA h g −1 at a current density of 0.1 A g −1 after 300 cycles, corresponding to an admirable capacity retention rate of 87.3% from the 2nd to 300th cycle. The SiO 2 @a‐TiO 2 composite with core‐shell structures has outstanding electrochemical performance, which is prepared by a low‐cost and facile solution approach, thus it is expected to realize the large‐scale production of SiO 2 ‐based anode materials.