Abstract：Porous silicon (P-Si) microspheres were obtained by dealloying method using AlSi powders as raw material. Then, the surface of P-Si microspheres was coated with polypyrrole (PPy) by in situ chemical oxidation polymerization to get PPy-coated P-Si microspheres (P-Si@PPy). Finally, P-Si@PPy was calcined at 800 ℃ for 3 h in an Ar atmosphere to obtain nitrogen-doped carbon-coated porous silicon (P-Si@NC) microspheres. The morphology, structure, and electrochemical properties of the as-prepared P-Si@NC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. The results show that the diameter of porous silicon microspheres is about 1 μm and the thickness of nitrogen-doped carbon layer is about 18 nm. When P-Si@NC composites are used as the anode of lithium-ion batteries, the initial discharge specific capacity is up to 2 609.2 mAh/g at a current of 0.1 A/g with a high coulombic efficiency of 87.5%, and a discharge specific capacity of 1 574.8 mAh/g is achieved after 50 cycles, exhibiting excellent electrochemical performance. The porous structure of P-Si@NC provides a buffer space for the expansion/contraction of silicon during the lithiation/delithiation process, and the nitrogen-doped carbon layer not only serves as a protective layer to maintain the particle integrity, but also accelerates the transfer rate of lithium ions and electrons.
柏凌鸿, 白玉婷, 雷霆. 氮掺杂碳包覆多孔硅微球的制备及电化学性能[J]. 粉末冶金材料科学与工程, 2021, 26(3): 219-226.
BAI Linghong, BAI Yuting, LEI Ting. Preparation and electrochemical performance of nitrogen-doped carbon-coated porous silicon microspheres. Materials Science and Engineering of Powder Metallurgy, 2021, 26(3): 219-226.
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