钠离子电池阴离子氧化还原材料结构设计与机制研究

钠离子电池阴离子氧化还原材料通过阴离子活性可提供较高比容量，从而有效降低钠离子电池的单位能量密度成本。但是，阴离子氧化还原反应存在一些基本科学问题，不可逆氧损失，动力学反应缓慢，主体结构稳定性差。本项目提出结合理论计算设计合成阴离子氧化还原材料，并调控材料的晶体结构、超结构、组分配比以及合成工艺等参数实现高的阴离子活性；结合原位拉曼光谱、微分电化学质谱和软X射线吸收谱等技术研究氧离子氧化还原反应的微观机制；利用离子掺杂、表面包覆等手段增强材料与氧的结合能力，增强阴离子氧化还原可逆性；通过阴阳离子氧化还原过程的分子动力学模拟与电化学测试，研究阴离子氧化还原的动力学特性，获得提升反应动力学的方法；通过研究主体结构演变规律和调控微观结构，获得稳定化阴离子氧化还原材料的策略。在此基础上，构建可逆性高、动力学反应快速、结构稳定性好的阴离子氧化还原新材料体系，为发展先进的钠离子电池技术提供技术支持。

The anion redox material releases a high reversible capacity based on anionic activity, which can effectively reduce the unit energy density cost of sodium-ion batteries. However, there are several basic scientific issues in the anionic redox reaction, such as the loss of irreversible oxygen, the sluggish kinetics and the poor stability of the layered structure. This project proposes to design and synthesize the anion-redox materials based on the theoretical calculation, and adjust the parameters of crystal structures, superstructures, compositions, and element ratios for target materials; to study the microscopic mechanism of oxygen redox reaction by in-situ Raman spectroscopy, differential electrochemical mass spectrometry and soft X-ray absorption spectroscopy; to enhance the ability of binding with oxygen, and reduce the side reaction of the electrode surface by means of ion doping and surface coating; to study the kinetic parameters of anion redox and obtain methods for improving reaction kinetics by molecular dynamics simulation and electrochemical test during anion-cation redox process; to obtain the strategy of stabilizing layered structure by studying the evolution mechanism of the main structure and regulating the microstructure. On the basis of above, this project will construct new anion redox material systems with high reversibility, fast kinetic reaction and good structural stability, and provide technical support for the development of advanced sodium-ion battery energy storage technology.