Preparation and Electrical Properties of Polyacrylonitrile Based Porous Carbon by Different Activation Methods

Polyacrylonitrile (PAN)-based porous carbon was prepared by different methods of activation with PAN polymer microsphere as precursor. The morphology, structure and electrical properties for supercapacitor of the porous carbon were investigated. It was found that the morphology of PAN nanospheres tended to be destroyed in the process of one-step activation (activation and carbonization were carried out simultaneously, and could only be retained when the amount of activating agent KOH was small). While the spherical morphology could be well reserved during the two-step activation method (carbonization and activation sequentially). The specific surface area and pore volume increased first and then decreased, with the increase in activation holding time for both one-step and two-step activation methods. The specific surface area reached the maximum value with 2430 m(2) g(-1) for the one-step activation method and 2830 m(2) g(-1) for the two-step activation method. Additionally, their mass-specific capacitances were 178.8 F g(-1) and 160.2 F g(-1), respectively, under the current density of 1 A g(-1). After 2000 cycles, the specific capacitance retentions were 92.9% and 91.3%.

Automated summary

PAN-based porous carbon was prepared by different activation methods, with two-step activation retaining spherical morphology better. The increase in activation time impacted the specific surface area and pore volume. Both one-step and two-step activation methods showed high mass-specific capacitances and good capacitance retentions after cycling.