SiO@C/TiO2 nanospheres with dual stabilized architecture as anode material for high-performance Li-ion battery

Abstract

Abstract Silicon-based materials have been widely used as anode materials in lithium-ion batteries (LIBs) because of the high specific capacity. However, there exist some shortcomings, especially in the thermal stability of the batteries, as well as huge volume expansion (＞300%) causes structural cracking. Herein, a core-shell structured SiO@C/TiO2 nanospheres has been successfully synthesized via ball milling and sol-gel method, the morphological, componential and thermal features are characterized with X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy. The results exhibit that the SiO could spontaneously absorb the huge volume expansion stress, the C/TiO2 shell as a compact fence was utilized to effectively enhance the electrical conductivity and further control the integrity and stability of well-wrapped core-shell framework during the charge/discharge processes. The electrochemical analysis show the SiO@C/TiO2 nanospheres possess a remarkably high initial coulomb efficiency of 97%. The reversible capacity can reach to 1565 mA h g−1 at 0.1 A g−1 after 100 cycles, which is higher than those of N–SiO (1353 mA h g−1) and SiO@C (1326 mA h g−1). Even at 2 A g−1, it exhibit a discharge capacity of 844.6 mA h g−1 after 220 cycles. This excellent performance can be primarily attributable to the well-designed core-shell structure of SiO@C/TiO2 nanospheres, where the outer rigid C/TiO2 coating can not only effectively alleviate the large volume change of SiO but also maintain the stable structure of anode materials, which are considered as a promising candidate to the anode material for new generation power LIBs.