Si–Ni–Carbon composite synthesized using high energy mechanical milling for use as an anode in lithium ion batteries

Si–Ni–Carbon composite was prepared by two-step high energy mechanical milling process. The microstructure was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometry (EDS). The electrochemical properties have been investigated until the 50th cycle. As a result, Carbon was coated on the surface of the Si–Ni composite, where Ni was distributed in Si matrix and the Si–Ni–Carbon composite demonstrated a large reversible capacity of ca. 960 with an excellent cycling stability. The reasons for good electrochemical characteristics were analyzed by high resolution transmission electron microscope (HR-TEM), powder resistance analysis and Barret–Joiner–Halendar (BJH) analysis. Uniformly dispersed Ni improved electronic conductivity and induced fast charge transport significantly in the Si–Ni–Carbon composite. In addition, pores and disordered Carbon layer played a role of media to accommodate a large volume change of Si during cycling. Our experiments suggest that the Si–Ni–Carbon composite should be a promising new anode material for lithium ion secondary batteries with a high capacity.