Cornlike Ordered Mesoporous Silicon Particles Modified by Nitrogen-Doped Carbon Layer for the Application of Li-Ion...

The cornlike ordered mesoporous silicon (OM-Si) particles modified by the nitrogen-doped carbon layer (OM-Si@NC) are successfully fabricated and used as the anode of lithium-ion battery (LIBs). The influences of the N-doped carbon layer on the structure and electrochemical properties of the OM-Si@NC composite are detailedly investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS), and charge/discharge tests. The results reveal that the amorphous N-doped carbon layer can offer the abundant conductive pathways for fast lithium ion transportation and electron transfer, which not only leads to a high specific capacity under high ampere density but also serves as a structural barrier maintaining the whole integrity and settling the mechanical breaking due to the huge volume changes of Si host. Therefore, the as-synthesized OM-Si@NC composite exhibits a high original discharge capacity of 2548 mA h g^-1 under 0.2 A g^-1 as well as a large reversible capacity of 1336 mA h g^-1 under 1 A g^-1 after 200 circles. The OM-Si@NC composite prepared by a relatively simple and feasible synthesis method shows excellent electrochemical performances and turns out to be promising for the application of high power LIBs.