钠资源丰富、成本低，钠基二次电池在储能领域潜力大。但由于其正极材料比容量低、结构稳定性差，负极材料循环稳定性差等缺点，限制了应用。本项目针对钠离子电池电极材料的高容量、循环稳定性、高比能（正极）相互兼顾的内在基础科学问题开展研究。通过对富碱锰基三元材料中Na/Li 比与掺杂对钠离子在多相间嵌钠‐脱钠行为的增强作用机制，三维多孔碳Sn 基合金复合结构对电极循环稳定性改善机理，揭示钠离子在多相多尺度材料中传输扩散动力学和电化学极化规律，利用多相多尺度结构可控性调控电极材料的结构稳定性、嵌钠/脱钠动力学及容量释放，实现高容量、高循环稳定性和低首次不可逆容量的统一，研制出高性能钠基储能关键材料及其高效、低成本制备方法。对于深化认识复相/复合结构电极材料及成分调控的嵌钠/脱钠特性均有普遍意义，支撑我国钠基二次电池基础科学研究和满足规模储能要求。

Since sodium is abundant in resources and low in cost, sodium-based secondary battery has drawn great attention in energy storage. However, its application has been limited due to the low specific capability and weak structural stability of the cathode materials associated with the poor cycling stability of the anode materials. In this work, a research focusing on the intrinsic basic scientific issues of high capacity, cycling stability and high specific energy (cathode materials) of the sodium ion battery electrode materials has been conducted. With the study on the mechanism of the Na/Li ratio and the insertion-extraction of the sodium ion in alkali-rich Mn-based ternary materials as well as the enhancing of the cyclic stability of the three-dimensional porous carbon Sn-based alloy composite structure, the ion diffusion kinetics and the electrochemical polarization principles of sodium ions in multiphase and multi-scale materials are revealed. The structural stability of the electrode materials and the kinetics of the insertion-extraction of the sodium ion as well as the capacity release are controlled by the controllable multi-phase and multi-scale structure. The unification of the high capacity, high cycle stability and low initial irreversible capacity are realized and the key materials of the sodium-based energy storage with the high performance are developed, meanwhile, the high-efficiency and low-cost preparation methods have also been discovered. The project is of universal significance to deepen the understanding of the electrode materials with the complex phase/composite structure as well as the composition regulation of the insertion-extraction of the sodium ion, which supports the basic scientific research of sodium-based secondary batteries and meet the requirements of the large-scale energy storage.