锰基锌离子电池正极材料的结构调控及储锌机制原位研究

Developing high-performance aqueous zinc battery is a hot topic in developing low-cost and high-performance energy storage micro-device area. However, the development of the cathode still remains a great challenge in both theoretically and experimentally, including the fast capacity fading, the unexplored mechanism, and the simultaneous increase in both energy and power density. This project aims at the design and preparation of high performance and durable Manganese-based zinc battery cathode. This project will study the interaction among crystal structure, surface/interface structure and morphology structure with ion diffusion energy barrier, electron transport, and cycling reversibility, and reveal the intrinsic reaction mechanisms through advanced in-situ characterization techniques. We will study the relationship among the surface/interfacial texture, ion diffusion energy barrier, element chemical environment and the electrochemical performance of Mn-based cathodes in real time. This project will bring a new direction and lay a scientific foundation for the development and in-situ characterization of high-capacity zinc ion battery cathode energy storage devices.

当前高性能水系锌离子电池的开发是低成本大规模储能和高效微纳器件领域研究的热点与前沿。然后，其正极材料的开发在基础理论和实际应用方面仍然面临诸多挑战，电极材料容量衰减快及其机理尚不明确、功率密度与能量密度难以协同提升等。本项目拟在纳米材料设计和原位表征技术积累的基础上，设计构筑高安全长寿命锰基锌离子电池纳米正极材料，组装锌离子电池和搭设基于微纳器件的原位表征平台，测试其电化学性能，揭示其内在规律。利用多种原位表征技术技术对电极材料的离子扩散特性、表界面结构等与容量衰减之间的内在联系进行原位检测。系统表征纳米材料的微结构演变，揭示电极材料的本征储锌机制。探明金属离子掺杂提升储锌性能的新机制，反馈并指导优化该正极材料的整体储锌性能，实现水系锌离子电池储能器件的功率密度和能量密度的协同提升，为实现水系锌离子电池高容量正极材料的制备及电化学机制的原位表征奠定科学基础。

通过元素掺杂（NH4+, Mg2+, Sn4+, H+等等）与复杂纳米结构设计构筑等方面，对其晶体结构、界面结构和形貌结构的稳定性进行优化与提升。系统研究锰基正极材料的组分、结构、表界面及反应机制对于锌离子电池正极材料的协同作用影响，发现通过合适的离子可以有效的调控电极材料的电导率，稳定其层间结构，从而实现锌离子电池器件的能量密度、功率密度和循环寿命协同提升。并通过原位透射电子显微镜、原位拉曼、原位红外等技术探索了锌离子电池正极材料的不同的电化学反应电位下的结构演化，揭示了电极材料的本征电化学行为及锌离子电池容量衰减的本质。开发了一种新型的电化学动力学分析模型，可以有效区分电化学反应本征速率与嵌入速率（传质）的影响，从而可以探明电化学反应本征速率。最终，优化后的正极材料、锌金属负极进行匹配，组装并优化商业化级别的高面积比容量的水系锌金属电池。项目研究成果为锌离子电池的商业化应用与开发提供科学依据。