Highly Flexible Freestanding Porous Carbon Nanofibers for Electrodes Materials of High-Performance All-Carbon Supercapacitors

Abstract

Highly flexible porous carbon nanofibers (P-CNFs) were fabricated by electrospining technique combining with metal ion-assistant acid corrosion process. The resultant fibers display high conductivity and outstanding mechanical flexibility, whereas little change in their resistance can be observed under repeatedly bending, even to 180°. Further results indicate that the improved flexibility of P-CNFs can be due to the high graphitization degree caused by Co ions. In view of electrode materials for high-performance supercapacitors, this type of porous nanostructure and high graphitization degree could synergistically facilitate the electrolyte ion diffusion and electron transportation. In the three electrodes testing system, the resultant P-CNFs electrodes can exhibit a specific capacitance of 104.5 F g(-1) (0.2 A g(-1)), high rate capability (remain 56.5% at 10 A g(-1)), and capacitance retention of ∼94% after 2000 cycles. Furthermore, the assembled symmetric supercapacitors showed a high flexibility and can deliver an energy density of 3.22 Wh kg(-1) at power density of 600 W kg(-1). This work might open a way to improve the mechanical properties of carbon fibers and suggests that this type of freestanding P-CNFs be used as effective electrode materials for flexible all-carbon supercapacitors.

Cobalt-doped mesoporous carbon nanofibres as free-standing cathodes for lithium–oxygen batteries

“…The sample presents the characteristic D band (at 1350 cm − 1 ) and the G band (at 1580 cm − 1 ). The D band results from the in-plane imperfections of the graphitic lattice and the G band is related to the existence of crystalline graphitic carbon [27]. In our case, the sample showed the two bands and therefore CNFs are based on a mixture of graphitic and disordered carbon (Fig.…”

“…3b is related to the (002) layers of graphite, which is maintained in the presence of the Co metal (JCPDS code #00-026-1076). As reported by Liu et al [27], during the carbonization process, Co ions of the metal salt are reduced into metal nanoparticles with different sizes. At the same time, the cobalt nanoparticles graphitize amorphous carbon into graphitic carbon.…”

“…In all the samples, the pore size did not vary with the Co acetate concentration in the precursor solution, as the average value was 3.6 nm. According to Liu et al [27], the cobalt salt can act as a catalyst of carbon consumption during thermal treatment. The Co salt is responsible for the formation of the pore structure as it acts as a porogen and as a catalyst [27].…”

“…According to Liu et al [27], the cobalt salt can act as a catalyst of carbon consumption during thermal treatment. The Co salt is responsible for the formation of the pore structure as it acts as a porogen and as a catalyst [27]. Such effect is directly related to the amount of Co(Ac) 2 in the precursor solution prepared for electrospinning.…”

Porous One‐Dimensional Nanomaterials: Design, Fabrication and Applications in Electrochemical Energy Storage

“…[53,80,286,287] Recently, Huang et al [80] produced bamboo-like Adv. To avoid the drawback of binders, porous nanofibers can be assembled into binder-free and self-standing films, which is promising in flexible energy storage applications.…”