Silicon cages with tailored mesopores as anodes for high rate performance lithium ion batteries

Silicon (Si) with high energy density is identified as the most promising candidate for commercial lithium-ion batteries anodes. Unfortunately, the volume expansion severely damages the battery cycle life during cycling, resulting in fast capacity fading during the battery operation. Herein, a facile design was proposed for the preparation of novel tailored mesoporous Si cages (TMSC) to mitigate this issue. The TMSC material, with mesoporous anamorphic spherical shells and nano-sized Si cores, consists of numerous interconnected channels and forms a half open three-dimensional network. When evaluated as electrode material for lithium-ion batteries, it exhibits the reversible capacity of 931.1 mAh/g after 200 cycles at 1 A/g, which is more stable than that of Si pomegranates with intact shells. Moreover, it displays a high rechargeable capacity of 552.3 mA h/g over 500 cycles at 4 A/g and the capacity decay ratio is only 0.11% for each cycle.