高性能硅负极材料电子/离子传导网构筑及作用机制研究

The present silicon anodes can not meet the need of high performance lithium batteries because of their fast capacity fading; Study on the oxidization of graphite, the purification of graphite oxide, the reuse of raw materials and adjusting approach of quality control to establish one method for the mass production of graphite oxide and graphene quantum dots with high quality, low cost and environmentally friendly; Investigate on the formation of multiple graphene oxide gel and change law in performance to build up the strategy for precise fabrication of graphene conduction network; Research on the building on electron/ion conductive network for the core-shell type silicon cathode and its action mechanism. On the basis, design and synthesize a series of silicon anode materials with a regularly change on the structure and property; Investigate on the microstructure and the properties of silicon anode materials and the synergistic effects. With the combination of quantum chemistry and physics of electrostatics, establish the theoretical model of structure-activity relationship for silicon anode materials; Set up the lithium battery research model and high power experiment device to evaluate the electrochemical performance of different electrode materials for lithium battery; Establish the prediction model of cell performance and cycle life to study on the relationship of material structure, properties and cell performances. On the basis, further perfect design idea of the silicon anode materials. .Completion of the project can make the research on silicon anode, graphene and related areas of China into the international frontier, this has the vital significance to promote international academic exchanges and personnel training.

现有硅负极因容量衰减快不能满足高性能锂电池需要；研究石墨氧化、氧化石墨纯化、物料回用和品质调控机制，建立高质量、低成本且绿色环保的氧化石墨及其量子点宏量制备方法；研究氧化石墨烯多重凝胶的形成和性能变化规律，建立高密度石墨烯传导网精准构建方法；研究核壳型硅负极材料电子/离子传导网构筑及作用机制，设计合成在结构和性质上呈规律性递变的硅负极材料；研究硅负极材料微观结构、性质和协同效应。结合量子化学和物理静电学，建立硅负极材料构效关系理论模型；建立锂电池研究模型和大功率实验装置，考察不同电极材料的电化学性能；建立电池性能评价和循环寿命预测模型，研究硅负极材料结构、性质和电池行为三者关系的规律性，完善硅负极材料设计思想。.研究成果应用于电动汽车，可大幅增加续航里程、缩短充电时间和延长使用寿命。项目的完成可使我国在硅负极、石墨烯及相关领域的研究进入国际前沿，对促进国际学术交流和人才培养都具有重要意义。

项目开展3D石墨烯的制备、功能化和性能研究，建立“多重凝胶”、 “w/o/w多重乳液模板法”和“ Pickering乳液模板法”等3D石墨烯构筑新方法。解决了3D石墨烯因“大而空”造成电学和力学性能不佳、因使用前“撕裂”造成电学和力学特性部分丧失、因缺少特定功能造成应用领域严重受限、因尺寸较大的石墨烯片重叠造成电催化活性位点大量减少等科学问题。开发了近三十种高密度石墨烯气凝胶、3D石墨烯微米球、3D石墨烯纳米球和3D石墨烯杂合微球，显著提升了3D石墨烯的电学性质、应用方便性和应用领域；项目开展石墨烯量子点的设计合成研究，开发了十二种功能各异的石墨烯量子点。通过对石墨烯量子点结构与光电性能关系研究，建立石墨烯量子点功能调控有效新方法；设计合成可与金属离子配位的功能石墨烯量子点，解决了金属离子在石墨片表面的固定问题，实现对电极材料晶体结构的有效调控，开发了系列高分散性石墨烯-金属纳米复合物；开展石墨烯-金属复合物的可控制备研究，实现不同电极材料与石墨烯之间的协同催化作用；开展硅负极材料电子/离子传导网构筑及作用机制研究，设计合成了在结构和性质上呈规律性递变的硅负极材料。通过对硅负极材料微观结构、性质和协同效应三者关系的深入探讨，结合量子化学和物理静电学，建立硅负极材料构-效关系理论模型；利用锂电池研究模型和大功率实验装置，研究不同电极材料的电化学性能，建立电池性能评价和循环寿命预测模型，揭示了硅负极材料结构、性质和电池行为的关系。所开发的硅-石墨烯复合负极在储锂容量、倍率特性和循环寿命方面得到明显改善，展示了在储能器件、光电催化、生物传感、高分子复合材料等领域的广阔应用前景和较好的理论价值。项目完成发表论文37篇，SCI收录35篇，申请发明专利21个，共培养青年教师2名、博士研究生3名和9名硕士研究生。