Heteroatom-doped porous carbon derived from zeolite imidazole framework/polymer core-shell fibers as an electrode material for supercapacitor

Abstract

In view of the respective advantages of electrical double layer capacitance (EDLC) and pseudocapacitance , the development of electrode materials with dual energy storage mechanisms (EDLC and pseudocapacitance) will play a significant role in maximizing the overall capacitance performance. In this paper, the core-shell fibers with dense zeolite imidazole framework (ZIF) coating were synthesized on the electrospun composite nanofiber substrate by a rapid in-situ growth strategy. After pyrolysis of ZIFs(shell)@PAN/PVP(core) fibers, heteroatom-doped porous carbon fiber materials with high specific surface area (410.55 m 2 g -1 ) were obtained. It not only had a layered porous structure , but also fully exposed the doped active sites, which made it have the advantages of EDLC and pseudocapacitance. As expected, the prepared porous carbon materials doped with rich heteroatom, as supercapacitor electrode materials, exhibited large specific capacitances of 492.7 F g −1 at a current density of 1 A g −1 and 406.4 F g −1 at 10 A g −1 . After 5000 cycles of galvanostatic charge-discharge at 10 A g −1 , its capacitance retention rate was as high as 98.65%, showing excellent charge storage performance and good cycle stability. Therefore, this work presents an effective strategy for the design and preparation of supercapacitor electrode materials with dual energy storage mechanisms.