基于钒酸盐普遍存在循环性能较差的问题，我们发展了一种新型结构更稳定的高容量钒酸铵电极材料。在已有工作基础上，本项目拟详细考察水热合成中溶液pH值和反应时间等因素影响，探索片状纳米形貌的形成规律；通过不同类型表面活性剂的特征吸附，可控合成具有不同裸露晶面的目标材料，研究裸露晶面与性能之间的关系，获取钒酸铵的最佳裸露晶面并研究相关反应机理；进一步对片状钒酸铵进行超声剥离以制备超薄纳米片，对比分析剥离前后材料结构和性能的变化，揭示超声剥离的制备机理；采用XRD、TG、XPS等手段深入研究NH4+在充放电过程中的行为；研究钒酸铵的电极动力学过程，考察其在锂离子脱嵌过程中的物相变化规律；深入剖析材料的晶体结构，结合核磁等手段，验证分子内氢键的存在可能，总结材料的高容量储锂机制。通过层间结构稳定化机制的探索，本项目有望获得长寿命和高倍率的超薄钒酸铵嵌锂材料，并丰富相关理论基础。

In view of the inferior cycling life for vanadates, NH4V3O8, a novel high-capacity cathode with relatively stable structure has been proposed in our group. Based on our previous work, herein, the effect of factors in hydrothermal method, such as solution pH values and reaction duration will be investigated in details and the formation regulation of the nanoflake-morphology will be explored. NH4V3O8 nanoflakes with different exposed facets will be synthesized via the certain absorption of various surfactants. The preferable exposed facets with higher electrochemical performance will be optimized and its reaction mechanism will be studied in this project. The as-prepared NH4V3O8 are expected to be further exfoliated into nanosheets with several nanometers in thickness by a high-intensity ultrasonic field. The structure and electrochemical performance of NH4V3O8 nanosheets before and after the treatment will be well compared and the probable exfoliation mechanism will be given. Meanwhile, the behavior of NH4+ group in crystal will be investigated by means of XRD, TG, XPS et al. The kinetics of electrode process and the structural variations during the lithium insertion/extraction process will be studied. For confirming the possibility of intramolecular hydrogen bond, the crystal structure will be deeply analyzed on the basis of structure model in combination with NMR results. Finally,the high-capacity lithium storage mechanism of NH4V3O8 nanosheets will be summarized. Ultra-thin NH4V3O8 nanosheets with long cycling life and high rate capability will be obtained and the strategies for stabilizing the layered structure in this project will greatly contribute to the development of vanadium-based compounds as intercalated materials.