Rambutan‐like hierarchically porous carbon microsphere as electrode material for high‐performance supercapacitors

Abstract

Used as high-performance electrodes, both structural and compositional alterations of carbon materials play very important roles in energy conversion/storage devices. Especially in supercapacitors, hierarchical pores and heteroatom doping in carbon materials are indispensable. Here the rambutan-like hierarchically porous carbon microspheres (PCMs) have been constructed via a hydrothermal treatment, followed by carbonization/activation. The hierarchically porous microstructure is composed of three-dimensional porous carbon networks, which give rise to a large surface area. Moreover, N and O functional groups are introduced in the as-prepared samples, which could generate the extra pseudocapacitance. Benefitting from the interconnected hierarchical and open structure, PCM exhibits outstanding capacitive performance, for example, superior specific capacitance and rate capability (397 and 288 F g −1 at 0.5 and 20 A g −1 , respectively), as well as long cycling stability (about 95% capacitance retention after 10,000 cycles). These encouraging results may pave an efficient way to fabricate advanced supercapacitors in the future.

Enhancement of Mass Transport for Oxygen Reduction Reaction Using Petal‐Like Porous Fe‐NC Nanosheet

“…Compared with melamine, DTPA played a vital role in optimizing the porosity and morphology, which was possibly caused by the unique 3D molecular structure and the release of more volatile molecules from the DTPA derivative during the high‐temperature pyrolysis. [ 55 ] Particularly, the external surface area was predominant in all catalysts (>70%, Table S2, Supporting Information), with FeNC‐D0.5 possessing the highest proportion of 91% and the highest pore volume of 1.34 cm 3 g −1 (Table S2, Supporting Information) among the FeNC‐D n .…”

Carbon‐based flexible self‐supporting cathode for lithium‐sulfur batteries: Progress and perspective

“…Pyridine nitrogen makes the lithium end of LiPSs be anchored through dipole-dipole interaction, whereas the π system formed between graphite nitrogen and sulfur end of LiPSs has a better phase. [29][30][31][32] Such a dual interaction enhances the absorption of LiPSs on the CNTs surface and improves the electrochemical activity and sulfur utilization.…”

“…The S/N‐CNT membrane obtained by vacuum filtration has a good conductivity, and the LSBs with this material as cathode have a good cycle and rate ability, which can be attributed to the formation of pyridine nitrogen, pyrrole nitrogen, and graphite nitrogen, reducing the shuttle effect. Pyridine nitrogen makes the lithium end of LiPSs be anchored through dipole–dipole interaction, whereas the π system formed between graphite nitrogen and sulfur end of LiPSs has a better phase 29‐32 . Such a dual interaction enhances the absorption of LiPSs on the CNTs surface and improves the electrochemical activity and sulfur utilization.…”

The synthesis of carbon microspheres film composed of nano‐onions and its application as flexible supercapacitors

“…Figure 5 shows the SEM images of the carbon products grown at 600°C for 10 min with different pressure (the atmospheric pressure condition and the vacuum [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]). It can be seen that the tubular and strip structures appeared in the product and no microsphere formed under the atmospheric pressure.…”

“…Carbon nanomaterials are widely used for electrodes of supercapacitors because of the unique structure and excellent physical and chemical performances, including high specific surface areas (SSAs), great conductivity, and superior mechanical property. 7,8 At present, many kinds of carbon nanomaterials have been used in energy storage, such as zero-dimensional (0D) carbon nano-onions (CNOs), 9 1D carbon nanotubes (CNTs), 10 and 2D graphene. 11 In the flexible supercapacitors, carbon films, especially these with composite structure, can improve the effective utilization of materials through the construction of composite.…”