In Situ Nitrogen‐Doped Covalent Triazine‐Based Multiporous Cross‐Linking Framework for High‐Performance Energy Storage

Abstract

Porous carbon as an electrode material has attracted extensive attention in the field of energy storage. Herein, to promote the energy density of carbon‐based materials, a class of in situ nitrogen‐doped 3D carbon skeleton with hierarchical pores through the structural evolution of pyridine‐incorporated porous covalent triazine‐based framework (p‐CTFs) is rationally designed and prepared. The controlled microscopic pore structure and nitrogen doping concentration can be achieved by varying the polymerization temperature. The experimental results show that p‐CTF‐800 has a large specific surface area (2795 m2 g−1), a rich nitrogen content (11.82%), and a broad pore size distribution (0.65–5 nm), and exhibited an excellent specific capacitance of 406 F g−1 in three‐electrode system and 245.7 F g−1 in water‐based symmetric supercapacitor. When using ionic liquid 1‐ethyl‐3‐methylimidazolium tetraflfluoroborate as electrolyte, the energy density can reach 77 Wh kg−1 at a power density of 175 W kg−1, and still remain at 56.4 Wh kg−1 even at a power density up to 8749 W kg−1. Moreover, p‐CTF‐800‐supercapacitor presents excellent cyclic stability (94% energy retention after 20 000 cycles for IL electrolytes) under current density of 4 A g−1. These results indicate that as‐prepared p‐CTFs can behave as excellent electrode candidate materials for the future high‐performance energy storage devices.

Pyrrolo[3,2-b]pyrrole-Based Covalent Triazine Framework: Three-dimensional Organization of Pores Using Nanostructural Spherical Carbon

“…Generally, the higher the pyrolysis temperature increases the SBET and the Cs values. This relationship was noticed for systems synthesized from terephtalonitrile, 61 pyridine-2,6-dicarbonitrile, 62 or tetrafluoroterephthalonitrile. 63 In some cases, high-temperature pyrolysis of CTFs results in highly porous materials with SBET value of about 3,120 m 2 g -1 (3,5-dicyanopyridine) or SBET value of about 2,500 m 2 g -1 (1,4-or 1,3-dicyanobenzene).…”

Fluorine/Nitrogen Co-Doped Porous Carbons Derived from Covalent Triazine Frameworks for High-Performance Supercapacitors

“…The G band (centered at ∼1597 cm –1 ) and D band (located at ∼1340 cm –1 ) indicate the graphitic and defective structure of materials, respectively. , As can be seen, the values of I G / I D increase from 0.93 to 1.11 as the pyrolysis temperature increases from 600 to 800 °C, revealing the higher graphitization of the obtained FNC material at the higher temperature. , The XRD patterns of three FNCs in Figure d show weak and broad peaks at around 24.5°, which can be attributed to the interlayer spacing of ∼3.4 Å and the (002) crystal plane of carbon. Such bulging peaks also imply their amorphous structure. − Note that the XRD patterns of FNC-700 and FNC-600 are slightly shifted to lower diffraction angles, manifesting their enhanced interlayer spacings, which may be attributed to the existence of more strongly electronegative C–F bonds in FNC-700 and FNC-600 compared to FNC-800. The C–F bonds with the strong interlaminar repulsion force enhance the delamination process and further enlarge the space of the interlayer .…”

“…According to GCD results, FNC-700 electrodes display an excellent cycling stability and a high C s of 326 F g –1 at 1 A g –1 , which are much better than those of FNC-600 (137 F g –1 ), FNC-800 (81 F g –1 ), and most of the reported carbon-based electrode materials derived from triazine-based COFs (Table S1). ,− ,− Even if the scanning rate rises up to 100 mV s –1 , the CV curve of FNC-700 can still retain its initial shape (Figure c), suggesting that FNC-700 has a great rate capability. ,− The superior rate performance is assumed to be related to the introduction of heteroatoms, that is, N and F atoms. The incorporation of the F element with strong repulsion may generate defects and a disordered structure, which may be in favor of providing an easier ion-diffusion path and further enhance the rate capability .…”

Nitrogen/Oxygen Enriched Hierarchical Porous Carbons Derived from Waste Peanut Shells Boosting Performance of Supercapacitors

“…[ 2,4,5 ] Owing to the high intrinsic conductivity, abundant morphology, large surface area, and tunable surface properties, porous carbons have been widely used as electrode materials for supercapacitors. [ 6–9 ] Various porous carbons have been fabricated from the green precursor of biomass, which exhibits outstanding performance in supercapacitors.…”

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conductivity, abundant morphology, large surface area, and tunable surface properties, porous carbons have been widely used as electrode materials for supercapacitors. [6][7][8][9] Various porous carbons have been fabricated from the green precursor of biomass, which exhibits outstanding performance in supercapacitors.Theoretically, the specific capacitance of a supercapacitor depends on the specific surface area of the carbonaceous electrode materials. The larger the surface area, the more the charge accumulated on the interface between the electrode and electrolyte distributions.

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