自支撑MPx（M=Co、Se）纳米线阵列的可控构筑及其储钠性能研究

Phosphorus shows the highest theoretical storage capacity and low oxidation reduction potential, which is an extremely potential anode material for sodium-ion batteries (SIBs). However, the low capacity and poor cycle performance due to the insulation and the huge volume changes of phosphorus during cycling hinder its large-scale application in sodium-ion batteries. To solve these problems, this project intends to employ the chemical combination of Co/Se and P to construct self-supported MPx (M=Co, Se) nanowire arrays with strong expansion resistance and high carrier mobility for sodium storage. The relationships of MPx component and sodium storage will be investigated to reveal the key factor for the electrochemical performance of phosphorus-based anode materials. The effects of MPx structure on sodium storage will be studied to exhibit the relationships between the microscopic structures of MPx nanowires array and the kinetics of sodium embedded, expansion/fall off and the stability of SEI. This study will provide powerful experimental basis and theoretical guidance for the design and preparation of phosphorus-based anode materials by understanding their sodium storage behavior.

磷（P）具有最高的理论储钠容量与较低的氧化还原电位，是一种极有潜力的钠离子电池负极材料。但因其导电性差和充放电时体积形变量大导致的电池容量低和循环性能差等问题阻碍了它的规模化应用。针对这些问题，本项目拟利用钠离子迁移率高、导电性良好的Se和导电率高、无体积形变的Co与P化合，构筑抗形变负荷能力强、载流子迁移率高的自支撑金属磷化物MPx（M=Co、Se）纳米线阵列并研究其储钠性能。考察MPx组成成分与储钠性能间的关系，揭示影响磷基负极材料电化学性能的关键要素；研究MPx结构对储钠性能的影响，揭示MPx纳米线阵列微观结构与嵌钠反应动力学、体膨胀/破裂脱落、SEI稳定性之间的关系。本研究将深入理解磷基负极材料的储钠行为，进而为设计与制备高效的磷基钠离子电池负极材料提供有力的实验依据和理论指导。

磷（P）具有最高的理论储钠容量与较低的氧化还原电位，是一种极有潜力的钠离子电池负极材料。但因其导电性差和充放电时体积形变量大导致的电池容量低和循环性能差等问题阻碍了它的规模化应用。针对这些问题，本项目利用钠离子迁移率高、导电性良好的Se和导电率高、无体积形变的Co与P化合，构筑抗形变负荷能力强、载流子迁移率高的自支撑金属磷化物MPx（M=Co、Se）纳米线阵列并研究其储钠性能。研究结果表明，微观结构、尺寸效应对无电化学活性的金属与磷化合形成的MPx纳米线储钠性能的影响较大，元素键合作用可用于改善由活性金属与磷化合形成的MPx纳米线储钠性能。本项研究为后续获得长循环寿命、高功率钠离子电池的研究探明了方向。