石墨毡表面原位生长碳微纳结构及其作为钠硫电池正极集流体的应用

Sodium sulfur cell is the most potentially energy-storage battery ,which has unbeatable advantage and potential applications in large-scale energy storage.The conductive property of its cathode current collector material (graphite felt)is an important factor to affect battery performance. However,the existing graphite felt possesses crude fiber and porosity, which results in the large positive resistance. Hence, it is the key to reduce the positive resistance. The project intends to study the carbon micro-nano structure (carbon silk, carbon nanotubes, etc) in-situ grown on the graphite felt. The resistance of current collector could be effectively reduced by means of increasing its specific surface area and the density of the conductive network. At the same time the carbon micro-nano structure can guarantee enough space to accommodate the sulfur of the positive active material. Through chemical regulation the different morphologies of micro-nano structured carbon composites are prepared in situ growth of the graphite felt. Moreover,the synthesis of the optimum condition is explored, and structural analysis and other means reveal the mechanism of affecting the morphology. With the best conditions the different morphologies complex are prepared and used as the sodium sulfur cell cathode current collector. The influence of sodium sulfur cell performance with the different morphologies of micro-nano structural complex has required further investigation. These results can provide a reliable experimental foundation and scientific basis for improving the sodium sulfur cell performance.

钠硫电池是目前最具潜力的一种储能电池，它在大规模能量存储方面有难以匹敌的优势和广阔的应用前景。其正极集流体材料(石墨毡)的导电性能是影响电池性能的一个重要因素，由于石墨毡纤维粗、孔隙率大，致使正极电阻较大，因此，进一步降低正极电阻是关键。本项目拟研究在石墨毡上复合生长碳微纳米结构(碳纳米丝,碳纳米管等),以此来增大集流体材料的比表面积、提高导电网络密度，从而有效降低集流体电阻；同时微纳结构的碳纳米丝或碳纳米管又能保证不显著减少石墨毡中容纳正极活性物质硫的空间。通过化学调控，在石墨毡的基体上原位生长制备出不同形貌微纳结构碳的复合材料，探索产物合成的最佳工艺条件，同时结合结构分析等手段来揭示影响产物形貌的机理。在此基础上将最佳条件制备的不同形貌复合物用作钠硫电池正极集流体，进一步研究具有不同形貌微纳结构特征的集流体对钠硫电池性能的影响规律，为有效提高钠硫电池的性能提供可靠的实验基础和科学依据。

钠硫电池是目前最具潜力的一种储能电池。其正极集流体材料(石墨毡)的导电性能是影响电池性能的一个重要因素，由于石墨毡纤维粗、孔隙率大，致使正极电阻较大，因此，进一步降低正极电阻是关键。本项目拟研究在石墨毡上复合生长碳微纳米结构(碳纳米丝,碳纳米管等)，以此来增大集流体材料的比表面积、提高导电网络密度，从而有效降低集流体电阻。我们通过CVD法成功的在石墨毡的基体上原位生长制备出了弯曲的碳纳米纤维；通过研究绿色环保的碳源材料，在石墨毡表面原位生长出了直立均匀的碳纳米纤维。研究成果已发表SCI收录论文6篇，申请发明专利一项。该项目的实施和完成不仅积累了经验，而且也为进一步开展相关研究奠定了良好的基础。