纳米钛硫化物可控合成及作为转换型负极的储钠特性研究

Transition metal sulfides (TMDs) have potential advantages of widespread materials availability, environmental benignity and high theoretical specific capacity which is a potential anode electrode material for sodium ion batteries. However, the volume expansion during the charge/discharge process and the dissolusion of intermediate sodium polysulfide in the ethers electrolyte, leading to low capacity utilization and poor long-term cycling performance of the material. In order to address this problem, this project is planned to achieve TMDs high capacity, long cycle and fast charge/discharge through using titanium sulphide which have strong sodium polysulfide adsorption characteristics as the anode sodium storage electrode and designing reasonable carbon coated nanostructures. Systematic investigations including exploiting the method of controllable synthesis of nano-titanium sulfides and advanced carbon coating technology, systematic study the physical and chemical properties and electrochemical properties of nano-titanium sulfide, summary the influence rules of nano-titanium sulfide structure, carbon source and carbon content on these parameters, reveal the chemisorption mechanism of titanium sulfide to sodium polysulfide and the convension sodium storage mechanic of titanium sulfide assiated by theoretical calculation. This project will open up and provide theoretical guidance and technical support for the designing high performance conversion TMDs sodium storage anode material.

过渡金属硫化物（TMDs）具有资源丰富、环境友好且理论比容量高的优势，是一种极具应用潜力的钠离子电池负极材料。然而，充放电过程中的体积膨胀以及中间产物多硫化钠在醚类电解液中的溶解流失，导致材料容量利用率低且长期循环性能不佳。为了解决这一问题，本申请从形貌调控、化学吸附以及物理限制三个方面出发，采用具有强多硫化钠化学吸附特性的钛硫化物作为储钠负极，通过设计合理的碳包覆纳米结构，实现TMDs的高容量、长循环以及快速充放电。具体研究内容包括，开发可控合成纳米钛硫化物方法以及先进碳包覆技术；系统研究纳米钛硫化物物理化学特性、电化学性能，总结纳米钛硫化物结构形貌、碳源、碳含量对这些参数的影响规律；结合理论计算，揭示钛硫化物与多硫化钠化学吸附机制，阐明钛硫化物作为转换型负极的储钠电化学反应机理。通过本项目实施，为发展高性能转换型TMDs储钠负极材料提供理论基础知识和技术支持。

过渡金属化合物具有资源丰富、环境友好且理论比容量高的优势，是一种极具应用潜力的钠离子电池负极材料。本项目围绕开发高性能过渡金属化合物储钠负极展开，设计合成了一系列电导率高、结构稳定的过渡金属氧/硫化物材料，如钛硫化物(TiS2, TiS, Ti2S)、钛氧化物(TiO, Ti2O)、硫化铜等，系统地研究了此类化合物的储钠电化学性能，阐明了材料结构与储钠性能的构效关系；通过非原位表征结合理论计算，分析了过渡金属化合物的结构演变，揭示了过渡金属化合物的储钠反应机理以及电化学动力学机制。通过本项目研究，为发展廉价且高性能的储能材料与器件提供了理论指导与技术支持。