碳网络支撑MoS2/金属纳米复合材料的嵌脱锂规律和电极过程研究

针对锂离子电池高比容量合金类负极材料存在纳米化过程复杂以及与碳等材料复合时不易分散的问题，从实用角度出发，提出一种可控碳框架网络包覆和支撑纳米金属复合材料制备方法：原料可以采用微米或者更大的金属颗粒，采用助磨剂及孔洞填充剂，以淀粉、柠檬酸、非离子型表面活性剂等为碳网络前驱体，球磨纳米化后高温热处理，除去填充剂留下金属膨胀空间，获得可控孔洞结构的碳框架包覆MoS2/金属纳米复合材料。研究该方法对不同金属负极Si、Sn、Al、Sb、Ge的适应性，通过调整模板设计适合不同金属负极的复合材料的空间结构，使金属和MoS2在充放电过程中，在碳网络中有合适的膨胀和收缩的空间，不会出现整体材料的巨大体积变化。采用多种分析手段对材料复合后的结构进行深入研究，利用原位表征技术探索材料的物相变化和结构变化，找出这类金属负极复合材料在电极过程中结构变化和嵌脱锂的规律。

The complexity of nanocrystallization and the difficulties of distribution in carbon materials have long been problems to the alloy materials with high specific capacity as anode materials for lithium ion batteries (LIBs). Proceeding from the reality, this program presents a method fabricating a kind of controlled carbon network coated/supported metals nanometallic composites. The metal powers with micron and even larger than micron scale can be selected as raw materials. Citric acid, starch and non-ionic surfactant are used as precursor of the carbon network. Then the raw materials and carbon precursor are nanocrystallized by ball milling in the presence of grinding agent and hole filling agent. After heat treatment, then the controlled carbon network coated/supported metals nanometallic composites with porous structure are left after the filling agent being removed. The adaptability of this method will be researched for different metals such as Si, Sn, Al, Sb and Ge. Different template structures are designed by adjusting template to be suitable to various metal-based anode composites. In the as-prepared structure, the metal and MoS2 has appropriate space to stand expansion and contraction in the carbon network during charge/discharge process then huge volume change of the whole material can be limited. The composite structure is deeply studied a variety of analytic means. The changes of phase and structure are explored by the in-situ characterization technique. The structural change and the insertion/extraction mechanism of lithium ions for the prepared metallic anode materials in electrode reaction will also be clarified.