多重网络导电聚合物复合水凝胶的可控制备及其自修复超级电容器电极材料研究

Flexible and wearable energy storage devices are easily scratched or damaged in the practical applications, resulting in problems including device failures and electrolyte leakages. These problems have become the bottlenecks for developing flexible and wearable energy storage devices. Inspired by the self-healing behaviors of living organisms in nature, this project intends to utilize the free-radical crosslinking copolymerization for the preparation of multiply-crosslinked polymer hydrogels, which can be used as the substrate for the sequent growth of conducting polymers with specific chain structures and controllable morphologies. The resultant conducting polymer composite hydrogels are expected to show self-healing properties by an efficient combination of conducting polymers with self-healing polymer hydrogel substrates. On one hand, the self-healing properties of polymer hydrogel substrates can be easily controlled by tailoring the multiply-crosslinked networks and their crosslinking density. On the other hand, the intrinsic self-healing properties of conducting polymers themselves can be designed by tailoring the interactions between the electrochemical and self-healing functional units in the chain structures of conducting polymers. New ideas and new methods for realizing the self-healing function-oriented structural design and controllable preparation of conducting polymer composite hydrogels will be provided. In addition, the relationship between structures, functional units and self-healing/electrochemical properties of the conducting polymer composite hydrogels and its regulation mechanism will be also revealed. Through the implementation of this project, it is expected to provide useful insights and database for the applications of new-type self-healing electrodes for flexible and wearable energy storage devices.

柔性可穿戴储能器件在实际应用中容易被划伤或损坏从而导致器件的失效以及电解液的泄露等问题，成为严重制约柔性可穿戴储能设备发展的瓶颈。受自然界中生物体自修复现象的启发，本项目提出自由基交联共聚制备具有多重交联网络的聚合物凝胶基体，设计合成具有特定侧链结构和可控形貌的导电聚合物，实现其与聚合物凝胶基体的高效复合，获得具有自修复性的导电聚合物复合凝胶电极材料。一方面通过调控聚合物凝胶基体的多重交联网络类型和交联密度提升复合凝胶材料的自修复性能，另一方面通过设计调控导电聚合物链结构中电化学和自修复功能单元间的相互作用进而赋予导电聚合物本征自修复性，为实现自修复导电聚合物复合凝胶材料的结构设计和可控制备提供新思路与新方法。揭示导电聚合物复合凝胶材料的组成-结构调控-自修复性/电化学性能之间的关系规律和调控机制，为其作为新型自修复电极材料在柔性可穿戴储能器件中的应用提供有益借鉴。

柔性超级电容器在现实应用中由于反复磨损和意外切割或刮伤造成机械损伤，进而导致器件性能大幅衰减甚至失效，已成为制约未来柔性超级电容器发展的瓶颈问题。作为超级电容器的核心组成，发展具有自修复性能的柔性超级电容器电极材料对于提高其可靠性和使用寿命至关重要。然而，目前自修复超级电容器电极材料普遍存在器件能量密度偏低、高自修复效率和高力学弹性难以兼顾等关键问题，限制了其广泛应用。本项目围绕导电聚合物复合水凝胶开展了系统研究工作，以多重网络聚合物凝胶作为自修复基体，实现其与导电聚合物的高效复合和界面调控，获得了兼具高力学弹性和自修复性的高性能导电聚合物复合水凝胶电极材料。本项目取得的主要研究结果如下：(1)发展了构筑分级响应网络的新策略，建立了简单高效制备自修复聚合物复合水凝胶的新方法；(2)提出了冷冻聚合构筑导电聚合物复合水凝胶的新策略，获得了高力学弹性和可自修复的新型导电聚合物复合水凝胶材料，拓展了其作为耐复杂形变和可自修复的高能量密度电极材料在柔性超级电容器中的应用；(3)基于自修复导电聚合物复合水凝胶材料构建了高性能自修复柔性超级电容器，揭示了自修复导电聚合物复合水凝胶的多层次结构与其自修复/电化学性能的关系规律。通过本项目的实施，发展了自修复导电聚合物复合水凝胶的可控构筑新方法，获得了耐复杂形变、可自主修复的新型导电聚合物复合水凝胶电极材料，为研制高性能自修复导电聚合物复合水凝胶电极材料及其在自修复柔性超级电容器等领域中的应用奠定了科学与实验基础。