P2/O3混型调控富碱Na/Li杂化锰基三元正极和三维碳网络锡基合金负极的材料设计合成及构建高比能储钠全电池与电化学性能研究

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.

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。

钠资源丰富、成本低，钠离子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。本项目按照任务书的任务，对储钠正负极材料进行研究，考察了其结构和电化学性能，发展了一系列储钠电极材料体系，为储钠二次电池发展提供了参考。主要内容包括：研制了三类嵌钠层状氧化物正极材料（富碱锰基三元材料、无钴镍锰二元材料和无钴镍锰铁三元材料），重点分析了富碱锰基三元正极材料的储钠构效关系，采用共沉淀-高温固相法与掺杂调控了其电化学P2-O2相变行为，首周放电比容量最高可达220 mA‧h‧g-1；开发了无钴镍锰二元和镍锰铁三元材料，采用高温固相法与掺杂调控了氧化还原反应对和电化学相变行为，发现了新的高压相变OP4相；发展了镍锡、锡锑和锡铁三种合金型锡基负极材料，采用限域模板-冷冻干燥-原位热解催化法合成构筑了三维多孔碳内嵌碳包覆纳米复合结构锡基合金，其中锡锑合金负极0.1 A‧g-1下循环200周比容量达359.2 mAh‧g-1。低成本制备的锰基钠离子电池正极材料体系能量密度高，循环寿命较长，具有良好的应用价值。同时研究了过渡金属硒（硫）化物纳米复合负极材料的设计合成及其储钠性能。这些成果为下一步开发适用于规模储能的钠离子电池奠定了坚实的基础。项目执行期间，发表重要学术论文27篇，其中2篇论文入选ESI高被引论文，授权中国发明专利21件；参与学术交流12次，作8次邀请报告；获教育部、河北省科技进步奖等3项；培养博士生2名，硕士生5名；专利成果转让5项。