Comparison of mechanically alloyed and sputtered tin–cobalt–carbon as an anode material for lithium-ion batteries

High energy ball milling, vertical-axis attritor milling and co-sputtering were used to prepare Sn30Co30C40 or Sn36Co41C23 electrode materials. By varying the milling conditions, it was possible to obtain nanostructured materials by mechanical methods whose X-ray diffraction patterns mimicked the diffraction pattern of the co-sputtered material. Electrochemical testing showed that composite electrodes made from each of the prepared materials showed stable charge–discharge capacity for at least 100 charge–discharge cycles and stable differential capacity versus potential profiles. Although the materials appear to be similarly nanostructured, the sputtered material showed a reversible capacity near 610 mA h/g, close to the theoretical capacity of 661 mA h/g, while the best material prepared by mechanical methods attained a specific capacity near 470 mA h/g. Further experiments are required to understand the differences in the nanostructure of these materials that leads to the differences in attained specific capacity.