ZIF-8衍生柔性多孔炭材料的制备及其电容性能研究

Flexible Porous Carbon Material Derived from ZIF-8 for Supercapacitive Performance

摘要:

随着柔性可穿戴电子器件的迅速发展，柔性储能电极材料引起众多学者们的广泛关注。金属有机框架结构（MOFs）衍生物具有优异的储能性能，但其本征无柔性的物理特性亟需解决。采用静电纺丝技术将ZIF-8结构单元嵌入纤维结构中，获得高电容性能柔性多孔炭纤维。同时，探究了ZIF-8的嵌入量（CF-ZIF-8-1.2）对柔性多孔炭纤维结构及电容性能的影响。实验结果表明：柔性多孔炭纤维CF-ZIF-8-1.2的比电容可以达到425.5 F?g^-1（电流密度为1 A?g^-1），并呈现出较小的电荷转移电阻（R_s=0.06 Ω）和接触电阻（R_ct=2.31 Ω），这主要归因于CF-ZIF-8-1.2具有较大的比表面积（212.83 m²?g^-1）、相对丰富的孔隙结构和丰富的N和O原子共掺杂。随后，进一步将其组装成对称柔性超级电容器（CF-ZIF-8-1.2//CF-ZIF-8-1.2），其能量密度高达7.6 Wh?kg^-1（功率密度为250 W?kg^-1），在不同弯曲角度和扭曲下呈现出优异的电容保持率（97%以上），说明柔性多孔炭纤维电极材料具有优异的柔性和稳定性。因此，CF-ZIF-8-1.2柔性多孔炭纤维材料具有潜在应用前景。

Abstract:

With the rapid development of flexible wearable electronic devices， flexible energy storage electrode materials have attracted extensive attention. Metal-organic framework （MOFs） derivatives have excellent energy storage performance， but their intrinsic issue of non-flexible physical properties needs to be addressed. In this work， ZIF-8 structural units were embedded into the fiber structure using electrostatic spinning to obtain flexible porous carbon fibers with high capacitance performance. Meanwhile， the effect of intercalation amount of ZIF-8 （CF-ZIF-8-1.2） on the structure and capacitive properties of flexible porous carbon fibers was investigated. Results showed that the flexible porous carbon fiber （CF-ZIF-8-1.2） displayed a high capacitance performance of 425.5 F?g^-1 （current density is 1 A?g^-1） as well as low charge transfer resistance （R_s=0.06 Ω） and contact resistance （R_ct=2.31 Ω）， owning to its large specific surface area （212.83 m²?g^-1）， relatively rich pore structure and abundant N and O atom co-doping. The porous carbon fiber was further assembled into a symmetric flexible supercapacitor （CF-ZIF-8-1.2//CF-ZIF-8-1.2）， which exhibited an energy density of 7.6 Wh?kg^-1 （power density is 250 W?kg^-1）. Meanwhile， CF-ZIF-8-1.2//CF-ZIF-8-1.2 symmetric flexible supercapacitor showed excellent capacitance retention （above 97%） at different bending angles and warps， indicating the flexible porous carbon fiber has excellent flexibility and stability. Therefore， the CF-ZIF-8-1.2 flexible porous carbon fiber has potential application prospects.