三维多孔二氧化锰/垂直石墨烯复合材料的可控制备及其柔性非对称超级电容器性能研究

The performance of electrode materials is one of the most importance factors for supercapacitors. How to obtain high-performance electrode materials with high mechanical flexibility via a large-scale and low-cost synthesis method has attracted considerable attention and still remained a huge challenge in the field of flexible supercapacitors. In this project, porous vertically-oriented graphene (VG) is synthesized on the three-dimensional flexible carbon cloth by plasma-enhanced chemical vapor deposition and chemical etching , and then the manganese dioxide is directly grow on the VG via liquid synthesis method, the obtained three-dimensional porous MnO2/VG composites are used as advanced binder-free electrodes for supercapacitors, to solve the problem of poor conductivity and flexibility of MnO2-based electrode; And introducing oxygen vacancies will employed to futher improve electrical conductivity of the oxide for making high performance and flexibility MnO2/VG composites; Secondly, we will deeply study the effects of synthesis conditions on the morphology, oxygen vacancy, structure, composition and capacitive properties of the composites to disclose the relationships among preparation-microstructure-electrochemical performance. Finally, to increase the operating voltage and boost the energy density of supercapacitors, flexible asymmetric supercapacitors (ASCs) based on the as-obtained MnO2/VG electrode as cathode will be assembled, and the key factors on the electrochemical performance of these ASCs will be also elucidated. The work will provide important theoretical and technical support to design high-performance flexible supercapacitor electrode material.

电极材料是决定超级电容器性能的关键因素之一。获得兼具高性能和高柔性的电极材料是目前柔性超级电容器研究领域的热点和难点。本项目拟通过在三维柔性碳布上构建多孔垂直石墨烯，并以此为载体在其表面原位生长二氧化锰，制备三维多孔二氧化锰/垂直石墨烯复合材料，来提高二氧化锰基电极材料的电容性能；在此基础上，通过调控纳米二氧化锰中氧空位浓度进一步改善氧化物的电导率，从而最终制备出具有高柔性和优异电化学性能的二氧化锰/垂直石墨烯复合材料。深入研究合成条件对复合材料的形貌、氧空位、结构、组成和电化学性能的影响及规律，揭示材料合成-微观结构-电化学性能之间的构效关系。通过采用不对称电极构建非对称超级电容器来提高工作电压，研制基于二氧化锰/垂直石墨烯复合材料的高性能柔性非对称超级电容器。本研究将为高性能柔性超级电容器电极材料的开发提供理论和技术支持。

电极材料是决定超级电容器性能的关键因素之一。获得兼具高性能和高柔性的电极材料是目前柔性超级电容器研究领域的热点和难点。本项目围绕研制高性能柔性超级电容器的目标，设计构筑了具有三维结构的高导电二氧化锰复合材料，构建了基于多孔柔性基底的可控合成方法，完成了系列三维二氧化锰复合材料的成功制备，掌握了复合材料的相关制备技术。同时研究了复合材料的电化学性能，揭示材料微观结构与电化性能之间的构效关系，主要研究结果包括：（1）采用电沉积法制备了基于多孔基底的垂直石墨烯，研究并构建了其可控合成技术，同时申请了相关的制备技术专利，此外通过两次电沉积制备了基于碳布的三维二氧化锰/石墨烯复合材料，该电极材料具有优异的电化学性能。（2）通过电沉积法制备了基于碳布的三维二氧化锰电极材料，与改性碳布组装成柔性非对称全固态超级电容器，该电容器表现出了较宽的电位窗口、大的比电容、高能量密度、稳定的循环能力和良好的机械柔性。（3）成功合成了一系列多孔复合电极材料，包括三维MnO2 /垂直取向石墨烯复合材料、三维MnO2 /碳纳米管复合材料、α-MnO2 /氮掺杂TiO2/CFP、Co-MnO2/CFP和富含氧空位的α-MnO2/CFP复合电极材料。（4）通过相关的表征及测试，探讨了各种复合电极的分级结构特征、氧空位特征、自支撑结构特征等与其高电容性能之间的构效关系。