Nitrogen- and oxygen-enriched 3D hierarchical porous carbon fibers: synthesis and superior supercapacity

Abstract

Supplementary InformaƟon (ESI) available: SEM and TEM images, the porous structure parameters, XRD patterns, electrochemical capacitive performances using a two-electrode and a three-electrode cell.. See Nitrogen-and oxygen-enriched hierarchical porous carbon fiber was fabricated by the phase-separable wet-spinning and the subsequent chemical activation of polyacrylonitrile (PAN) precursor. The wet-spinning could readily offer an interpenetrating 3D meso-/macro-porous network owing to the phase-separation of PAN in the coagulation bath (DMSO/ H2O), caused by the different solubility of PAN in DMSO and H2O, and the different content of PAN in fiber and the coagulation bath. The later chemical activation introduced abundant small-sized nanopores within the meso-/macroporous network skeleton. The obtained hierarchical porous carbon fiber exhibited high specific surface area of 2176.6 m 2 g -1 , large pore volume of 1.272 cm 3 g -1 , and was highly doped by heteroatoms of nitrogen and oxygen. When it was used as supercapacitor electrodes, high performance of reversible specific capacitances of 329 F g -1 at 0.1 A g -1 and 223 F g -1 at 20 A g -1 as well as the capacitance retention of 97.6% after 2000 cycles were achieved in a two-electrode cell.

Block copolymer–based porous carbon fibers

“…Our PCFs displayed 33% better capacitive performance than KOH-activated carbon fibers, e.g., the N and O dual-doped, KOH-activated PCFs reported by Li et al . ( 47 ) with a capacitance of ~270 F g −1 at 1 A g −1 . Our block copolymer–based PCFs were not subjected to any chemical activation or postsynthesis treatments.…”

Fast Microwave Synthesis of Hierarchical Porous Carbons from Waste Palm Boosted by Activated Carbons for Supercapacitors

“…In addition, three-dimensional (3D) structures of carbon materials as electrode materials can further facilitate the rapid diffusion of ions [14,15], and doping with heteroatoms (e.g., oxygen, nitrogen) can promote the wettability of carbon surface and participate in the Faradaic reaction contributing to pseudo-capacitance [16,17,18]. However, to fabricate this hierarchical porous carbon (PC) with heteroatom doping, hard templates (e.g., SiO 2 ), complicated subsequent synthesis, and chemical agents (e.g., urea) are often required [19,20]. Consequently, the high cost and time-consuming synthesis have severely hindered the application of supercapacitors.…”

Flexible and Wearable All‐Solid‐State Supercapacitors with Ultrahigh Energy Density Based on a Carbon Fiber Fabric Electrode

“…[32,33] However, the mechanical strength of these micron-sized fibers is not sufficient for weaving or knitted using a textile machine due to the large pore volume. [32,33] However, the mechanical strength of these micron-sized fibers is not sufficient for weaving or knitted using a textile machine due to the large pore volume.…”

“…More recently, N/O‐enriched, micron‐sized carbon fibers with high surface area and large pore volume (including micro/meso/macroporous) have been fabricated using the wet‐spun method and exhibited excellent electrochemical performances and better mechanical strength than those made of carbon powders or short fibers . However, the mechanical strength of these micron‐sized fibers is not sufficient for weaving or knitted using a textile machine due to the large pore volume.…”