新疆煤基多孔硬碳/锡复合纤维负极材料的设计、构筑及储钠性能研究

Sodium-ion battery is an attractive and alternative energy storage technology to replace lithium-ion battery, because of its abundance (uniformly distributed everywhere across the world) and inexpensive cost for preparing sodium-based electrode materials. However, develop suitable anode materials for sodium-ion battery would be one of the key issues. .Porous hard carbon/tin nanofiber composite has excellent performance for sodium ion batteries, due to the composite can combines the merits and mitigate the shortcomings of both the components. However, the synergetic effect between the porous hard carbon and Sn nanopaticles, and the correlation between the performance and synthesis method of the composite is uncertain. What’s worse is the high price of the carbon resouces, which limits its application in sodium ion batteries..In the project, porous hard carbon/tin nanofiber for sodium-ion battery will be prepared by two methods from Xinjiang coal. The composition and structures of raw coal are investigated, and the effects of technic parameter on composition, structure and morphologyanalyze will be studied as well. Furthermore, the correlations between electrochemical properties and composition, structure and morphology of the materials are discussed. The route for synthesis superior electrochemical performance of porous hard carbon/tin nanofiber from Xinjiang coal will be built through optimize synthesis technic parameter and mathematical model. On the one hand, the work will develop the synthetic methods of porous hard carbon/tin nanofiber from coal in theory to realize the controllable preparation of porous hard carbon/tin nanofiber anode materials; on the other hand, it will also provide theoretical and scientific basis for the development of high-performance anode materials for sodium ion batteries by optimizing the technic parameters of the assembly and testing process, and discussing the synergetic effect mechanism of porous carbon and Sn nanoparticles for storge Na+ ion.

钠离子电池具有资源丰富、价格低廉等优点，是当前研究热点。而发展相应的负极材料已成钠电池的关键问题。硬碳/锡纤维负极材料因结构稳定、容量高备受关注，但碳与锡协同机制和材料构效关系不明确，且所用碳源价格昂贵。.本项目以新疆煤为碳源，深入开展煤基多孔硬碳/锡复合纤维的制备与储钠性能研究。分析原料煤的组成与结构，优选适合硬碳纤维生产的煤质，建立煤基多孔硬碳/锡复合纤维的制备工艺；阐明材料制备工艺-微观结构-宏观性能（储钠）的相关性，揭示能量转化过程中材料结构、形貌、元素价态等变化对电化学性能的影响规律，弄清碳/锡协同储钠机制，以期实现对材料性能的调控和提升，获得高性能煤基多孔硬碳/锡复合纤维负极材料。该项目将在理论上发展并丰富煤基碳/锡复合纤维的合成方法学，为优势资源转化利用提供思路；同时，探究碳与锡协同机制，阐明材料结构与性能的构效关系，为设计、合成高性能硬碳基负极材料提供理论基础和科学依据。

本项目以新疆煤为碳源，深入开展煤基多孔炭纤维及其复合材料的制备与电化学性能研究。分析原料煤的组成与结构，优选出黑山煤为研究对象；采用混酸对原料煤进行功能化，并研究改性煤结构、形貌、元素价态等信息变化，探究了混酸改性机制，获得具有良好溶解性的改性煤。调控制备条件、活化工艺等，建立了煤基炭纤维及其复合材料的制备方法，成功制备出一系列煤基炭纤维及复合材料；探究了材料制备工艺-微观结构-宏观电化学性能间相关性，实现了材料性能的有效调控和进一步提升。相关研究为煤基炭纤维功能材料在高能量密度钠（锂）离子电池中的应用奠定了坚实的科学技术基础，为提升煤炭资源的附加值提供了实验数据参考。