Monday, 14 May 2018: 10:10
Room 607 (Washington State Convention Center)
Hybrid Si/C materials have attracted huge attentions during the past 20 years. The attempts include core/shell, yolk/shell, nanotubes, nanowires and etc. However, the cost of the synthesis of these materials are high and requires complex methods and sufficient time. Therefore, the researchers switched to micron-size silicon as starting material and tried to fabricate composites of silicon with other conductive materials. It was proven that silicon, with more than 300% volume change during charge/discharge process, and low conductivity, cannot satisfy the needs, individually. Among the conductive materials, graphite (Gr) was the first choice. However, the Si/Gr composites did not deliver significant capacity in the first experiments. Here, we looked at the problem again and proposed a new method to elaborate the capacity of Si/Gr composites. This approach is based on size reduction and uniform mixing of silicon and graphite at first stage, followed by conformal carbon coating and creating empty voids inside the composite at the last step. The obtained results are comparable to previous experiments and the whole synthesis can be done with minimum cost in reasonable time.