Performance of Partially Exfoliated Nitrogen‐Doped Carbon Nanotubes Wrapped with Hierarchical Porous Carbon in Electrolytes

Abstract

The preparation of highly conductive, high-surface-area, heteroatom-doped, porous carbon nanocomposite materials with enhanced electrochemical performance for sustainable energy-storage technologies, such as supercapacitors, is challenging. Herein, a route for the large-scale synthesis of nitrogen-doped porous carbon wrapped partially exfoliated carbon nanotubes (N-PPECNTs) with an interconnected hierarchical porous structure, as an advanced electrode material that can realize several potential applications for energy storage, is presented. Polypyrrole conductive polymer acts as both nitrogen and carbon sources that contribute to the pseudocapacitance. Partially exfoliated carbon nanotubes (PECNTs) provide a high specific surface area for ion and charge transportation and act as a conductive matrix. The derived porous N-PPECNT displays a nitrogen content of 6.95 at %, with a specific surface area of 2050 m g , and pore volume of 1.13 cm g . N-PPECNTs, as an electrode material for supercapacitors, exhibit an excellent specific capacitance of 781 F g at 2 A g , with a high cycling stability of 95.3 % over 10 000 cycles. Furthermore, the symmetric supercapacitor exhibits remarkable energy densities as high as 172.8, 62.7, and 53.55 Wh kg in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([BMIM][TFSI]), organic, and aqueous electrolytes, respectively. Also, biocompatible hydrogel and polymer gel electrolyte based, stable, flexible supercapacitors with excellent electrochemical performance could be demonstrated.

Effect of Different Nitrogen Configurations on Sodium Storage Properties of Carbon Anodes for Sodium Ion Batteries

“…The peaks at 399.2 ± 0.8 eV, 397.8 ± 0.6 eV, and 400.8 eV can be assigned to pyrrolic N, pyridinic N and quaternary N, respectively. − Among those three bonding configurations of nitrogen atoms, the content of pyrrolic N for PL-600, pyridinic N for PD-600 and quaternary N for BA-600 are calculated to reach 80.3%, 38.9%, and 66.9%, revealed in Figure f and Table S1, respectively. In particular, the content of N-5 is much higher than that of nitrogen-doped carbon materials reported in the previous literature. − Until now, it is always believed that N-6 plays a major role in the storage of alkali metal ions. ,, However, through experimental verification, when the content of N-5 is high enough, the same or even better performance can be achieved, because the introduction of N-5 can enhance the conductivity, enlarge the interlayer distance and increase defects for sodium storage. In addition, as illustrated in Figure S8, compared with N-6 and N-Q, the introduction of N-5 will cause more active sites in the carbon material itself.…”

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO2 hybrid composite

“…The specific capacitance ( C m ) of the electrode for the Cu/CuO/PCNF/TiO 2 composite can be calculated from the discharge profiles using the following equation [22–24]:…”

Three-Dimensional Hierarchical Porous Carbons Derived from Betelnut Shells for Supercapacitor Electrodes

“…in which C s is the specific capacitance (F g −1 ), I is the applied current, ∆t is the discharge time (s), V is the working potential window, and m is the mass of the active material [30]. Two BSPC-based symmetrical SC cells were assembled with 1 M KOH as the aqueous electrolyte and evaluated over the voltage window of 0.0 to 0.6 V. Likewise, in case of full-cell symmetrical SC, the specific capacitance, energy density, and power density were evaluated as follows:…”