Linear-Polyethyleneimine-Templated Synthesis of N-Doped Carbon Nanonet Flakes for High-performance Supercapacitor Electrodes

Abstract

Novel N-doped carbon nanonet flakes (NCNFs), consisting of three-dimensional interconnected carbon nanotube and penetrable mesopore channels were synthesized in the assistance of a hybrid catalytic template of silica-coated-linear polyethyleneimine (PEI). Resorcinol-formaldehyde resin and melamine were used as precursors for carbon and nitrogen, respectively, which were spontaneously formed on the silica-coated-PEI template and then annealed at 700 °C in a N2 atmosphere to be transformed into the hierarchical 3D N-doped carbon nanonetworks. The obtained NCNFs possess high surface area (946 m2 g−1), uniform pore size (2–5 nm), and excellent electron and ion conductivity, which were quite beneficial for electrochemical double-layered supercapacitors (EDLSs). The supercapacitor synthesized from NCNFs electrodes exhibited both extremely high capacitance (up to 613 F g−1 at 1 A g−1) and excellent long-term capacitance retention performance (96% capacitive retention after 20,000 cycles), which established the current processing among the most competitive strategies for the synthesis of high performance supercapacitors.

Linear-PEI-Derived Hierarchical Porous Carbon Nanonet Flakes Decorated with MoS2 as Efficient Polysulfides Stabilization Interlayers for Lithium–Sulfur Battery

“…For the CNNFs, the typical 3D hierarchical porous structure possessing 3D interconnected nanotube nanoflakes can be observed (Figure 2a,b), similar to our previous reports for L-PEI template and its derivative materials. 53,57 The diameters of the carbon nanotubes are about 15−20 nm, while their length can reach up to hundreds of nanometers or several micrometers. Also, as shown in the TEM image (Figure 2e), there are large amounts of meso-to macro-scale pores among the adjacent carbon nanotubes.…”

“…Three peaks located at 397.6, 399.0, and 400.4 eV are found, which can be attributed to pyridinic-, pyrrolic-, and graphitic-N, respectively. 53 Due to the strong electronegativity of nitrogen, N-doped carbon materials usually introduce chemisorption of lithium polysulfides through the Li−N interactions. 34 The relatively low peak intensity for O−CO demonstrates the reduction of oxygencontaining groups from carbon materials after annealing.…”

“…Synthesis of the MoS 2 -Decorated CNNFs (CNNFs-MoS 2 ). Carbon nanonet flakes (CNNFs) are synthesized according to our previous report 53 (more details can be found in the Supporting Information, SI). PEI (Figure 1a) is first transformed from PEI−H + (Scheme S1 in SI) and then PEI@SiO 2 nanotubes (Figure 1b) are formed after mixing PEI and TMOS at proper temperature.…”

2D/1D V2O5 Nanoplates Anchored Carbon Nanofibers as Efficient Separator Interlayer for Highly Stable Lithium–Sulfur Battery

“…: 41-1426, space group of Pmmn (59), a = 11.5 Å, b = 3.6 Å, and c = 4.4 Å) was also given as reference [51]. According to the XRD results, there were two broad peaks centered at around 25.0 • and 43.2 • for the CF, which can be indexed to the (002) and (100) diffractions of crystalline carbon [52,53]. For the V-CF, all the recorded XRD peaks can be assigned to the orthorhombic V 2 O 5 , without detections of any other vanadium oxides within the accuracy of measurements.…”

Preparations of NiFe2O4 Yolk-Shell@C Nanospheres and Their Performances as Anode Materials for Lithium-Ion Batteries

“…Studies have shown that the existence of the porous structure can accelerate the dynamic process of ion diffusion in the structure, and a large specific surface area can increase the contact area between the electrode and the electrolyte and improve electrochemical performance [ 48 , 49 ]. In order to compare the specific surface area and pore size of NFO-YS@C and NFO-S@C, the N 2 adsorption–desorption isotherms and pore size distributions are shown in Figure 4 .…”