Advanced Supercapacitors Based on Porous Hollow Carbon Nanofiber Electrodes with High Specific Capacitance and Large Energy Density

Abstract

Hollow carbon nanofibers with hierarchical porous shells were prepared by NaOH activation of the electrospinning SiCNO fibers, followed by carbonization treatment. By adjusting the carbonization temperature, porous hollow carbon nanofibers with different Brunauer−Emmett−Teller (BET) specific surface areas and total pore volumes are obtained, both of which are explored as electrode materials for supercapacitors. It was found that the obtained products (HCF800) possess the highest BET specific surface area of 2628.10 m 2 /g and the largest pore volume of 2.32 cm 3 /g when the carbonized temperature was designed at 800 °C, thus displaying the best supercapacitor performance. The electrochemical results in a three-electrode system show that HCF800 exhibits a high specific capacitance of 330.11 F/g as the discharge current density is 1 A/g and still maintains 65.3% of its original specific capacitance when the current density reaches 20 A/g. Moreover, in a twoelectrode system, HCF800 also exhibits an excellent specific capacity of 259.86 F/g at a current density of 1 A/g, marvelous cyclic stability with the specific capacitance retention of 95.3% even after 10,000 cycles, and a large energy density of 12.99 W h/kg at 1.0 A/g. Significantly, the supercapacitor performance of these porous hollow carbon nanofibers is also superior to that of many previously reported carbon materials, which proved them to be worthy candidates for high-performance electrode materials.

Structural design and mechanism analysis of hierarchical porous carbon fibers for advanced energy and environmental applications

“…From a polymer perspective, high dosages of sacrificial component will lead to a highly porous structure in CFs. 91,92 Kang's group successfully fabricated PCFs with well-distributed interconnected meso- and macro-pores derived via electro-blown spinning of PVA/PTFE blends. 93–96 The obtained highly porous structure offered more active sites for catalyst doping compared with normal CFs, which efficiently avoided the accumulation of the catalyst.…”

Yeast-Based Porous Carbon with Superior Electrochemical Properties

“… 9 In the past few years, many outstanding work on the preparation of biomass-based carbon electrodes has received much attention. Examples such as tofu, 10 cotton, 11 flour, 12 onions, 13 elm flower, 14 cornstalk, 15 coconut shell, 16 and synthetic carbon materials are assembled into supercapacitor electrodes for potential energy storage applications.…”

Ultrahigh‐Areal Capacitance Flexible Supercapacitors Based on Laser Assisted Construction of Hierarchical Aligned Carbon Nanotubes

“…i) Ragone plot shows the relationship of energy and power density of the hierarchical VACNT-based flexible SC and compared with other reported literatures. [8,9,49,50]…”

“…The volume energy and power density of VACNT-based SC is ≈0.5 W h cm −3 and 90 W cm −3 , which is superior to other recently reported flexible carbon-based SCs. [8,9,49,50] The excellent performance can be attributed to this fact that the Al micro grid-based VACNTs with high specific surface area can be directly used as electrodes without additional binders or conductive additives, which ensures the electrolyte accessibility to the electrode surfaces and offers an opportunity to optimize the rapid ionic diffusion in Al micro grid-based VACNT electrodes, resulting in the increase of energy density and power density. These results further demonstrate that Al micro grid-based VACNT SCs have great potential as an independent power source for small electronic devices.…”