నైరూప్య

Silicon Carbide-Derived Carbon Coated Graphitized Mesocarbon Microbead Composites for Anode of Lithium-Ion Battery

Zhengwei Cui , Ye Cong , Xuelian Du , Xuanke Li , Jiang Zhang , Zhijun Dong , Guanming Yuan and Yanjun Li

Unique silicon carbide-derived carbon (SiC-CDC) and graphitized mesocarbon microbead (GMCMB) composites (GMCMB@SiC-CDC) were prepared by solid reaction of GMCMB and silicon and following etching reaction with chlorine. The microstructure of SiC-CDC was characterized as mainly amorphous carbon combined with some short and curved sheets of graphite. N2 adsorption/desorption isotherms and pore size distributions proved the composites presented both an enormous amount micropores centered at around 0.5~0.6 nm and a few mesopores (2~50 nm). The GMCMB@SiC-CDC composites showed higher specific surface area and pore volume, especially the microporous surface area and volume. The composites as the anode materials manifested much higher charge specific capacities of 877.6 mAh·g-1 at the first cycle compared with pure GMCMB of 359.6 mAh·g-1, which was probable that Li ions could insert into not only carbon layers but also micropores. The GMCMB@SiC-CDC composites presented better discharge specific capacities at higher charge/discharge rates. The component and electrochemical performances of the composites can be optimized through changing the molar ratio of GMCMB/Si to control the corresponding proportion of SiC-CDC and GMCMB.