锑烯基纳米复合材料的电化学可控制备及其钠离子电池负极性能研究

Sodium-ion batteries (SIBs) are now recognized as the most promising alternative to lithium-ion batteries. Exploitation of Na-storage anode materials with excellent electrochemical performance is the critical issue for the development of SIBs. Antimony (Sb) is an appealing anode material for SIBs because of its large theoretical capacity and low discharge potential. However, due to huge volume change during sodium ion insertion and extraction, bulk Sb shows a quick capacity decay. In this project, halogenated antimonene will be synthesized by an efficient and economical electrochemical exfoliation and synchronous halogenation method. Furthermore, electrochemical growth of conducting polymer (CP) on the surface of halogenated antimonene will be conducted to construct core-shell halogenated antimonene@CP nanocomposites. This method takes full advantage of the precise regulation of the electrochemical reaction conditions to realize the compositional and structural control of the nanocomposites. On this basis we will further investigate the relation between composition, structure and Na-storage performance and expect to develop antimonene-based SIBs anode materials with excellent electrochemical performance. This study will provide valuable insight into the controllable synthesis of two-dimensional materials and their functional materials and be helpful to accelerate the study and applications of SIBs.

钠离子电池被公认为是替代锂离子电池的首选，开发高容量、高倍率和长寿命的负极材料则是钠离子电池应用的核心问题。锑由于具有高容量、低放电位的特点，是一种非常有前景的钠离子电池负极材料。但锑在嵌/脱钠过程中存在严重的体积膨胀，导致循环性能迅速衰减。本项目拟通过高效、经济的电化学剥离与同步原位卤化的方法一步得到卤化锑烯，进一步在卤化锑烯外表面通过电化学聚合法生长一层导电聚合物（CP)，获得具有核壳结构的卤化锑烯@CP纳米复合材料。该制备方法充分利用电化学反应条件可以精准调控的优点，实现复合材料中锑烯厚度、掺杂卤素种类与掺杂效果、壳层CP种类与厚度等组成和结构的可控调节。在此基础上，深入研究复合材料组成、结构和储钠性能之间的科学关系，以期获得高容量、高倍率和长寿命的钠离子电池锑烯基负极材料。该项目的开展将为二维材料及其功能化材料的可控制备提供重要参考，为钠离子电池的深入研究和广泛应用奠定基础。

锑烯是体相锑减薄至原子层厚的二维材料，具有超薄的厚度和超高的表面积，在储能、光电、催化等领域展示出巨大的应用前景。为了实现其应用，如何高效制备高质量的超薄锑烯是一个重要挑战。电化学剥离法是一种可规模化制备二维材料的方法，具有快速高效、绿色环保、低成本等优点，而且所得二维材料品质更高。在本项目资助下，取得了以下成果：（一）系统研究了锑在无机盐类和有机盐类电解质溶液中的电化学剥离行为，发现在硫酸钠水溶液中以硫酸根离子作为插层离子剥离金属锑的方法可以制得厚度均一的高质量超薄锑烯；（二）探索了功能化锑烯材料的制备，获得了超薄的二维氟化锑烯材料，同时完成了锑烯/石墨烯纳米复合材料的构建，系统的研究了锑烯/石墨烯纳米复合材料的电化学性能；（三）进一步拓展了以羧甲基纤维素锑作为前驱体可控制备核壳结构纳米锑@多孔碳复合材料，并系统的研究了其电化学性能。该项目的开展将为二维材料及其功能化材料的可控制备提供重要参考，对推动钠离子电池在储能领域的广泛应用奠定基础。