Mesoporous silicon/carbon hybrids with ordered pore channel retention and tunable carbon incorporated content as high performance anode materials for lithium-ion batteries

Abstract

In-situ magnesiothermic reduction reaction route was developed to synthesize mesoporous Si/C (silicon/carbon) hybrids with ordered pore channel retention and tunable carbon incorporated content as high performance anode materials for LIBs (lithium ion batteries). The effect of carbon incorporation on the microstructures and electrochemical performance of the Si/C hybrid LIBs anodes is investigated. The incorporation of carbon in the Si/C hybrids not only prevents the ordered structure of mesoporous silicon from collapsing, but also increases the electrical conductivity of the synthesized Si/C hybrids. The as-prepared Si/C hybrid LIBs anode with an optimal carbon content of 7.05 wt%, displays improved electrochemical performance with a high reversible specific capacity, rate capability and excellent cyclic performance, showing a higher specific capacity of up to 1452 mAh g−1 at a current density of 200 mA g−1 after 100 cycles and a high coulombic efficiency of up to 99.2%. The great improvement of the electrochemical performance of the ordered mesoporous Si/C hybrid LIBs anodes can be attributed to the unique ordered structure, large surface area, the homogeneously incorporated carbon in the Si/C hybrids. The synthesized ordered mesoporous Si/C hybrids are promising for potential applications as LIB anode materials with enhanced electrochemical performance.