Nitrogen‐Doped Porous Carbon Derived from Carbazole‐Substituted Tetraphenylethylene‐Based Hypercrosslinked Polymer for High‐Performance Supercapacitor

Abstract

Nitrogen-doped porous carbons are synthesized by KOH activation of hypercrosslinked 1,1,2,2-tetrakis (4-(9H-carbazol-9yl)phenyl)ethene (HTCP) polymer for efficient supercapacitor application. The obtained materials possess combined microporous and mesoporous structures with high BET surface area of upto 2226 m 2 g À 1 and nitrogen content of upto 2.62%. These structural properties result in increased accessible surface and redox sites for enhanced electrochemical capacitive storage. Effects of nitrogen functionalities and carbonization temperature on the porous materials are studied by monitoring the capacitive behaviours of the samples. The material afforded by carbonization of HTCP at 700°C (HTCP-700) offers a high specific capacitance of 445 F g À 1 (1 A g À 1 ) and excellent cycle durability of nearly 100% retention upto 10000 cycles in 1 M H 2 SO 4 electrolyte. The cyclic voltammetry and galvanostatic charge-discharge experiments indicate a good rate capability (278 F g À 1 at 20 A g À 1 ). The supercapacitor device fabricated with PVA-H 2 SO 4 gel electrolyte using HTCP-700 as an active material delivered maximum energy density of 11.6 W h kg À 1 .[a] N.

Calcium Chloride Activation of Mung Bean: A Low‐Cost, Green Route to N‐Doped Porous Carbon for Supercapacitors

“…The mung bean carbons with different structures and compositions offer a chance for investigating the structure‐performance relationship of bio‐carbon as supercapacitor. Based on other works, two points are beneficial to the specific capacitance of carbon material: (1) hierarchical nanostructure composed of macroporous and meso/microporous, which facilitates fast mass transport, along with large surface area for electrical charge storage; (2) heteroatom doping generate extra pseudocapacitance As shown in Figure , the specific capacitance was calculated by GCD curves and correlated with BET surface area, N content, charge transfer resistance Rct, and defect degree I D /I G . The results indicate that the specific capacitance correlates positively to the BET surface area, N content, and I D /I G .…”

Formation of High Surface Area Hierarchical Porous Carbon Via a Novel Two Step Activation Process for Fast Supercapacitors

“…Besides, we have calculated the pseudocapacitance contribution for the S3 sample at scan rate from 5 to 50 mV s À 1 The results of the double layer capacitance and total capacitance are shown in Figure S11a, and the double layer capacitance contribution are at different scan rates are shown in Figure S11b. [26] We can find that the double layer capacitance contributes to the most of the capacitance due to the large specific surface area of the prepared sample. All these electrochemical results demonstrate that the synthesized HPC is suitable for high-rate and highly stable supercapacitor applications.…”

“…It shows a specific capacitance retention of 82.3 % for 10000 cycles, indicated the stable cycling performances. Besides, we have calculated the pseudocapacitance contribution for the S3 sample at scan rate from 5 to 50 mV s −1 The results of the double layer capacitance and total capacitance are shown in Figure S11a, and the double layer capacitance contribution are at different scan rates are shown in Figure S11b . We can find that the double layer capacitance contributes to the most of the capacitance due to the large specific surface area of the prepared sample.…”

3D Hierarchical structure Electrodes of MnO2 Nanosheets Decorated on Needle‐like NiCo2O4 Nanocones on Ni Foam as a cathode material for Asymmetric Supercapacitors

“…5 shows Nitrogen adsorption–desorption isotherm of PPC, BHC and BPC. All three materials display type I isotherms,, typical of microporous structure. The surface areas calculated by using a multipoint BET model of PPC, BHC and BPC are 1054 m 2 /g, 1166 m 2 /g and 1572 m 2 /g, respectively.…”