Silicon-multi-walled carbon nanotubes-carbon microspherical composite as high-performance anode for lithium-ion batteries

Silicon-multi-walled carbon nanotubes-carbon (Si-MWNTS-C) microspheres have been fabricated through the ball milling and spray drying method followed by the carbonization process. The as-prepared composite microspheres are confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The specific capacity of the as-prepared microspherical composite as anode in lithium-ion batteries (LIBs) is about 1100 mAh g⁻¹ at the current density of 0.2 A g⁻¹ (based on the total weight of the composite). At the high current density of 6 A g⁻¹, the Si-MWNTS-C microspheres exhibit reversible capacity of 415 mAh g⁻¹. Through the ex situ SEM, we observed that the Si-MWNTS-C microspherical composite particles have no extinct change on the electrode surface except for the growth of the spherical particles after 100 cycles. The excellent electrochemical performance is ascribed to the synergistic effect between Si nanoparticles (Si NPs) and MWNTS-C microspheres. The as-prepared Si-MWNTS-C microspheres can effectively accommodate large volume changes and provide a 3D conductive network during the lithiation–delithiation processes.