石墨烯复合物薄膜的制备及其在柔性非对称超级电容器中的应用

The new methods of programmably assembling graphene-based nanocomposite films will be developed. By these methods, the graphene-based composite films that possess excellent conductivity as well as high mechanical and electrochemical properties will be achieved. These graphene-based composite films can serve as the electrodes of flexible asymmetric supercapacitors. In addition, the kinetics model of assembling graphene-based nanocomposite films will be built and the dependence of the physical and electrochemical properties of these graphene-based nanocomposite films on their microstructure will be investigated. Based on these graphene-based nanocomposite films and solid state electrolytes, all-solid-state flexible integrated asymmetric supercapacitors with high performance will be designed. The resultant asymmetric supercapacitors can meet the demand of their applications in different bending states. The platform of in-situ characterizing the materials and devices of flexible asymmetric supercapacitors will be built. Combining the theoretical calculation and simulation, the relationship between structure and performance of electrode materials will be understood. Furthermore, during the charge and discharge process, the structural transform of electrode materials and the transmission of energy and mass at different bending states will be studied.

本项目将发展石墨烯与赝电容材料纳米复合和可控程序化组装的新方法，制备力学、电学和电化学性能兼备的石墨烯与赝电容材料的复合物薄膜，建立石墨烯复合物薄膜可控组装的动力学模型和构效关系，实现石墨烯复合物薄膜的性能优化。直接利用石墨烯与赝电容材料复合物薄膜作为电极材料，利用固态电解质，设计组装高性能、全固态和一体化的柔性非对称超级电容器器件，使其能够满足在不同弯曲状态下服役的需求。搭建原位表征柔性非对称超级电容器的材料和器件测试平台，结合理论计算，准确和全面的理解柔性非对称超级电容器材料和器件的构效关系及器件充放电过程中材料结构演变、能量传递与物质传输规律。

近年来，柔性可穿戴电子设备的高速发展促使其供能器件向着“轻、薄、柔”等方向发展。非对称超级电容器功率密度高、循环寿命长且安全性高、环境友好，设计组装高性能柔性非对称超级电容器对于促进柔性可穿戴电子设备的发展具有重要意义。电极材料的制备是柔性超级电容器设计的关键。本项目基于石墨烯和聚苯胺等材料，发展了金属还原自组装法和真空抽滤法等多种石墨烯及其复合物薄膜的制备策略，建立了石墨烯复合物薄膜可控组装的动力学模型和构效关系，获得兼具高力学、电学和电化学性能的石墨烯膜及石墨烯基复合膜电极。例如，以金属还原自组装法制备了还原氧化石墨烯（RGO）薄膜及聚苯胺/还原氧化石墨烯（PANI/RGO）复合物薄膜，该石墨烯与赝电容材料的复合膜具有良好的导电性，且复合膜在弯曲近180°时电导率仍能达到原始状态的98.5%，表现出良好的柔性。在此基础上，进一步以RGO薄膜为负极，PANI/RGO复合膜为正极，PVA/H2SO4为凝胶电解质组装了柔性全固态一体化非对称超级电容器。通过搭建拉伸台等原位测试装置，结合电化学性能测试平台，对材料和器件进行了系统的性能测试。结果表明，器件在弯曲近180°时，容量可达到原始未弯曲状态的98.4%，且在原始及弯曲状态下均表现出优异的循环稳定性。此外，器件经过反复多次弯曲后仍具有优异的电化学稳定性，其可弯曲次数大于500次。同时，结合有限元模拟等理论计算方法系统地研究了柔性一体化储能器件在弯曲状态下的力学行为。准确和全面的分析正常和弯曲形变下材料和器件的结构演变、能量传递规律。项目中实现了高稳定、超轻质、全固态和一体化柔性储能器件的设计组装，将有助于加快柔性储能器件的实用化进程，促进柔性电子设备发展。