钠离子电容器纳米复合电极材料的强偶联设计构筑及协同机理

Na-ion batteries share the merits of both secondary batteries with high energy densities and supercapacitors with high power densities. They will be ideal next-generation, large-scale electrochemical energy-storage devices, since their key materials are low-cost and resource-abundant. This project focuses on the research and development of anode (e.g., Ti, Nb, W-based oxides and sulfides) and cathode (e.g., 2D graphene and Mxene-type carbides) materials for high-performance Na-ion capacitors. The strategies including the strongly coupled assembly and functionalization will be utilized for designing and fabricating composite nanoarchitectures. The microstructure, electrochemical performance, tailoring mechanism of the resulting nanostructured electrode materials will be explored in detail. The essential relationship between the nanoarchitectural assemblies and the electrochemical properties as well as the evolution rules will be clarified. The strong-coupling interaction (e.g., chemical covalent bonds, hydrogen bonds, π-π conjugated effects) among the assembled nano-units, and the related synergistically enhanced effects will be systematically investigated. Furthermore, we will try to clarify the reaction mechanism, and surface/interface stability, electrode compatibility, and performance failure of Na-ion capacitors, and grasp the rules for the compatibility between the anodes and cathodes, and the electrode and electrolytes. It is expected that this research would both lay the scientific foundations and provide beneficial guidance for the design, fabrication, optimization, and feasibility of Na-ion capacitors, thus promoting the discipline cross and fusion of materials, chemistry, energy, etc.

钠离子电容器兼有二次电池能量密度高与超级电容器功率密度高的优点，其关键材料资源丰富、成本低，是用于规模储能较理想的下一代电化学储能器件。本项目旨在研发高性能钠离子电容器的负极（Ti、Nb、W基氧化物/硫化物）、正极（二维石墨烯、Mxene类碳化物）材料，采用强偶联组装与功能化等策略设计构筑复合纳米结构，探索强偶联复合电极材料体系的结构、优异特性及其调控机制，揭示强偶联纳米结构组装体与电化学性能的本质联系及其演变规律，阐明复合电极材料体系中组装单元间的共价键、氢键、π-π共轭等强偶联协同增效机制。研究钠离子电容器内部反应机理、表界面稳定性、电极相容性及器件性能衰减机制，掌握正负极适配性、电极/电解液相容性规律，为钠离子电容器的设计、构建、性能优化及其实用化提供理论与实验指导，促进材料、化学、能源等学科的交叉融合。

本项目采用原位自组装、原子层沉积、静电纺丝等创新的材料制备方法，设计合成与可控构筑了系列BiSb合金@C、T-Nb2O5/C、TiO2/MoS2@NC、V2O5@PEDOT/Graphene等纳米复合电极材料，系统研究了晶相结构、表面键合、纳米复合等关键因素对储钠/电荷储存电化学性能的影响规律。结合第一性原理理论计算，揭示了快速赝电容离子传输、“表面偶联”协同提升电荷传输机制。探索了纳米复合电极材料在混合钠离子电容器中的应用基础，研究了储钠电极动力学特征及其与电容电极的匹配性，为发展高性能长寿命大规模储能器件提供理论模型与实验基础，对推动低成本钠离子电容器的产业化应用具有重要的意义。在本项目研究内容的基础上，进一步拓展并初步验证了快充储能器件在极端环境温度的应用可行性。标注该项目资助的SCI学术论文20余篇，主要发表在Adv. Energy Mater.、Energy Storage Mater.、J. Mater. Chem. A、Chem. Eng. J.、Small、Sci. China. Mater.、J. Energy Chem.等著名国际学术期刊上，受到了国内外同行的广泛关注。获湖北省自然科学一等奖（排名第二）。入选2018-2021年度科睿唯安全球高被引科学家。培养博士后2名、博士生8名、硕士生9名。