锑/离子液体衍生的氮掺杂碳复合物作为钠离子电池负极材料研究

Antimony has attracted enormous attention as anode materials for sodium-ion batteries due to its high theoretical gravimetric capacity (660 mA h/g). However, antimony suffers from huge volume changes during repeated sodium insertion/extraction processes, which results in Sb particles pulverization and aggregation as well as loss of electrical contact, leading to rapid capacity fading upon cycling. This project aims to prepare Sb/ionic liquids-derived nitrogen-doped carbon composites through a two-step strategy including mixing cyano-containing ionic liquids with SbCl3 and subsequently pyrolyzing. The as-synthesized composites are expected to have the following features, such as small Sb nanoparticles, uniform distribution, porous carbon network, and strong interaction between Sb nanoparticles and nitrogen-doped carbon matrix. The electrochemical properties of the composites as anode materials for sodium-ion batteries will be investigated in detail. We hope to circumvent the unsatisfactory electrochemical performance of Sb-based sodium-ion battery anodes. This project will explore the effect of ionic liquid species, pyrolysis temperature, addition of conductive additive, and introduction of template on sodium storage properties. The excellent Sb-based sodium-ion battery anode materials will be developed with high capacity, superior rate capability and long cycle life, which can provide theoretical and experimental basis for development and application of sodium-ion batteries.

由于具有较高的理论容量（660 mA h/g），锑在作为钠离子电池负极材料时受到广泛关注。但是，在重复的嵌/脱钠过程中锑经历巨大的体积变化，这会导致锑颗粒的粉化与聚集以及失去电接触，并最终导致容量的快速衰退。本项目通过先混合含氰基离子液体和三氯化锑，再将混合物热解处理制备出锑/离子液体衍生的氮掺杂碳复合物。这类复合物有望具有以下特征：较小的锑纳米颗粒、均匀的颗粒分布、多孔的碳基底、锑纳米颗粒与氮掺杂碳之间存在强的相互作用。系统研究这类复合物在作为钠离子电池负极材料时的性能，期望可以解决目前锑基钠离子电池负极材料电化学性能差的问题。探讨离子液体种类、热解温度、掺入导电添加剂、引入模板等对储钠性能的影响。开发出具有高容量、高倍率、长循环寿命的锑基钠离子电池负极材料，为钠离子电池的应用提供理论和实验依据。

锑因为具有高理论容量（660 mAh g−1）和合适的工作电压，被认为是最有前途的钠离子电池负极材料之一。尽管具有这些优势，锑在嵌/脱钠过程中存在严重的体积膨胀（~390%）会导致差的循环稳定性和倍率性能，这是锑在钠离子电池中应用所面临的重要挑战。为了解决这个难题，我们以氰基离子液体和三氯化锑等为前驱体，通过简单混合再热解的方法制备出锑/离子液体衍生的氮掺杂碳复合物，并将所得复合物用作钠离子电池负极材料。通过改变实验条件（如离子液体种类和热解温度等）调节了锑/碳复合物中锑颗粒的尺寸、锑颗粒在碳基底中分散性、锑颗粒与碳基底之间相互作用，改善了锑基材料在作为钠离子电池负极时存在的循环稳定性和倍率性能差的问题，所制备的锑/碳复合物均表现出较好的储钠性能和商业化应用前景。在0.1 A g−1电流密度下，Sb/N-rGO循环500圈后可逆容量为473 mAh g−1。项目负责人以第一/通讯作者发表SCI论文15篇、中文核心期刊2篇，其中影响因子9.0以上的5篇。研究工作受到国内外同行的广泛关注、引用和好评，截止目前，共被他引422次。