Yolk structure of porous C/SiO2/C composites as anode for lithium-ion batteries with quickly activated SiO2

Abstract A yolk structure of C/SiO2/C and a hollow structure of C/SiO2 composites with porous feature are synthesized by one-step method and two steps method, respectively. When evaluate as an anode material for lithium-ion batteries (LIBs), the C/SiO2/C and C/SiO2 deliver an impressive cycle performance and exhibit an excellent rate capacity. More importantly, attributing to the one-step synthesis method of C/SiO2/C, it possesses interconnected micropore and higher special surface area, which provide a more efficient ionic transportation path and facilitate the diffusion of Li+ between the electrolyte and C/SiO2/C, thus the activation time of SiO2 can be effectively shorten. The capacity achieves the steady value of 1135 mAh g−1 (based on the weight of SiO2 in the electrode material) only by 60 cycles at 50 mA g−1 which is much faster than that of C/SiO2 and delivers a high-rate capacity of 390 mAh g−1 at 1000 mA g−1. Considering the good lithium storage abilities and fast-activated features, the C/SiO2/C composites hold promise in applications in practical LIBs.