Zhao Weiwei, Wang Weikang, Peng Jiali, Chen Tiantian, Jin Beibei, Liu Shujuan, Huang Wei, Zhao Qiang
Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, P. R. China.
Dalton Trans. 2019 Jul 2;48(26):9631-9638. doi: 10.1039/c8dt05069d.
Two-dimensional (2D) metal porphyrin frameworks (MPFs) with a π-conjugated skeleton, high surface area, and more accessible active sites have been applied as active materials for supercapacitors, but the poor electrical conductivity limits the enhancement of electrochemical performance. Moreover, MPF-based flexible supercapacitors have been rarely reported. Here, for the first time, we fabricated wrinkled 2D ultrathin 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin copper(ii) (Cu-TCPP) nanosheets through the surfactant-assisted synthetic method. The as-obtained wrinkled Cu-TCPP nanosheets were further composited with conductive polypyrrole (PPy) to construct a flexible Cu-TCPP/PPy film through the combination of the electrophoretic deposition method and electrochemical polymerization technology. The wrinkled 2D ultrathin Cu-TCPP nanosheets not only offer macroporous channels for fast ion/electron transport, but also effectively reduce the transmission path of electrolyte ions. The PPy affords 3D conductive networks for rapid electron transport and enhances the electrochemical kinetics. The synergistic effect of Cu-TCPP and PPy leads to the enhanced supercapacitive performance of Cu-TCPP/PPy in comparison with the individual components. As a result, the freestanding Cu-TCPP/PPy electrode shows a capacitance of 340.6 mF cm-2 at 1 mA cm-2, 71.14 F cm-3 at 0.1 A cm-3, and 163.34 F g-1 at 0.2 A g-1, more than 45% greater than that of the pristine PPy film of 224.6 mF cm-2, 48.15 F cm-3 and 92.2 F g-1 at the corresponding current densities. Moreover, the fabricated binder-free symmetric supercapacitor possesses a maximum energy density of 2.27 μW h cm-2 at the highest power density of 50 μW cm-2. This work provides a new strategy to design 2D metal-organic framework-based flexible all-solid-state supercapacitors with high energy storage performances.
具有π共轭骨架、高比表面积和更多可及活性位点的二维（2D）金属卟啉框架（MPF）已被用作超级电容器的活性材料，但较差的导电性限制了其电化学性能的提升。此外，基于MPF的柔性超级电容器鲜有报道。在此，我们首次通过表面活性剂辅助合成法制备了具有褶皱的二维超薄5,10,15,20-四（4-羧基苯基）卟啉铜（II）（Cu-TCPP）纳米片。通过电泳沉积法和电化学聚合技术相结合，将所制备的具有褶皱的Cu-TCPP纳米片与导电聚吡咯（PPy）进一步复合，构建了一种柔性Cu-TCPP/PPy薄膜。具有褶皱的二维超薄Cu-TCPP纳米片不仅为离子/电子快速传输提供了大孔通道，还有效缩短了电解质离子的传输路径。PPy提供了三维导电网络以实现快速电子传输，并增强了电化学动力学。与单个组分相比，Cu-TCPP和PPy的协同效应使Cu-TCPP/PPy的超级电容性能得到增强。结果，独立的Cu-TCPP/PPy电极在1 mA cm-2时的电容为340.6 mF cm-2，在0.1 A cm-3时为71.14 F cm-3，在0.2 A g-1时为163.34 F g-1，分别比相应电流密度下原始PPy薄膜的224.6 mF cm-2、48.15 F cm-3和92.2 F g-1高出45%以上。此外，所制备的无粘结剂对称超级电容器在最高功率密度50 μW cm-2时的最大能量密度为2.27 μW h cm-2。这项工作为设计具有高储能性能的基于二维金属有机框架的柔性全固态超级电容器提供了一种新策略。
