磁场诱导离子凝胶聚合物电解质二维通道及离子传递特性

The design and fabrication of high-performance polymer electrolytes has been a huge challenge for the development of solid-state energy storage techniques. This project will focus on the key scientific problems that restrain enhancing the ion conducting performance of solid polymer electrolytes. To overcome these conundrums, this project aims to build numerous continuous and anisotropic channels by employing ultrathin 2-dimensional nanosheets and arranging them in a highly ordered form under a very strong magnetic field. In addition, the microstructures of these channels will be modulated by changing the types and size of ions absorbed onto the nanosheets. New synthetic strategies for the preparation of high-conducting solid sate polymer electrolytes will be obtained expectedly by studying the size effect and spatial configuration effect of ions, as well as the orientation effect of channels on the ion transport mechanisms. Ion transport functions in complex polymers will be hypothesized on the base of experimental results, and therefore dynamics and control methods can be developed by mathematical treating miscellaneous functions. In addition, multiscale coupling mechanisms between the microstructures of polymer electrolytes and ion conducting properties will be studied to clarify new mathematical description models and mesoscale coupling interactions. The success of this project will create a new multiscale research and development protocol for the electrolyte compositions—synthetic process—microstructure modulation—performance optimization, and will also drive the development and applications of ionogel polymer electrolytes.

构筑高性能聚合物电解质是发展固态储能技术的一个重要前沿课题。本项目针对提高聚合物电解质离子电导的关键技术难题，提出以二维超薄纳米片为填料，采用强磁场诱导其在聚合物基体中规则排列来获取连续通道，通过纳米片上修饰离子的构型及尺寸来调节通道的微结构；研究离子传递的尺寸效应、空间构型效应和通道取向的影响规律，获取制备高离子电导聚合物电解质的新方法；构筑离子在复杂体系中的传输模型，通过复杂函数的数学处理掌握离子动力学规律及调控方法；发展聚合物电解质微观结构和离子传导特性的跨尺度耦合机理，形成基于机理模型的数理描述方法，构建其介尺度关联方法。通过项目的实施，形成电解质组分-制备工艺-微结构调控-性能优化的多尺度协同研发体系，推动离子液体基凝胶聚合物电解质的应用。

锂金属电池其能量密度约为锂离子电池的一倍，是全球各国的研究热点。锂金属电池面临的关键科学难题包括：①不致密沉积带来的枝晶、死锂等问题，导致电池库伦效率低、安全性差。②锂负极剥离/沉积过程导致电极厚度变化，进而影响电池厚度、破坏界面稳定性。③固态电解质尽管可以很好的解决枝晶问题，但一方面其电导率-电化学稳定性-加工性能难以平衡，超薄高导通柔性固态电解质是科技部十四五固态电池研究的重点之一；另一方面，降低正极/电解质界面阻抗、构筑电极内部连续的离子电子通道也是固态电池面临的巨大挑战。本项目针对上述关键技术难题，以纳米复合凝胶聚合物电解质的离子电导调控为核心，以IL电解质、固态电解质与电极之间的界面两个角度为抓手，通过精确控制固体填料种类、复合方式和离子通道尺寸、维度、取向性及连续性，剖析了离子在复杂体系中的跳跃行为、电解质微结构与离子传递之间的构效关系、多离子相互影响及协同规律，获得调控固体电解质离子电导特性的方法。深入研究了跨尺度的内在关联，揭示了不同尺度之间的耦合协同关系，建立了调控电解质的数理模型和方法，发展出设计合成高性能复合聚合物电解质的新理论及新工艺。