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Hierarchical clews of carbon nanobelts (CsCNBs) with surface area up to 3445 m2g−1have been synthesized by a template-free method from low cost raw materials.

Single electric double-layer capacitors cannot meet the growing demand for energy due to their insufficient energy density. Generally speaking, the supercapacitors introduced with pseudocapacitance by doping heteroatoms (N, O) in porous carbon materials can obtain much higher capacitance than electric double-layer capacitors. In view of above merits, in this study, nanoporous carbon materials with ultrahigh N enrichment (14.23 wt%) and high specific surface area (942 m 2 g −1 ) by in situ introduction of N-doped MOF (ZTIF-1, Organic ligands 5methyltetrazole/C2H4N4) were produced. It was found that as supercapacitors' electrode materials, these nanoporous carbons exhibit a capacitance as high as 272 F g -1 at 0.1 A g −1 , and an excellent cycle life (almost no attenuation after 10,000 cycles.). Moreover, the symmetric supercapacitors were assembled to further investigate the actual capacitive performance, and the capacitance shows up to 154 F g -1 at 0.1 A g −1 . Such excellent properties may be attributed to a combination of a high specific surface area, ultrahigh nitrogen content and hierarchically porous structure. The results shown in this study fully demonstrate that the nanoporous carbon materials containing ultrahigh nitrogen content can be used as a potential electrode material in supercapacitors.

Hollow carbon nanospheres (HCNs) with specific surface areas up to 2949 m g and pore volume up to 2.9 cm g were successfully synthesized from polyaniline-co-polypyrrole hollow nanospheres by carbonization and CO activation. The cavity diameter and wall thickness of HCNs can be easily controlled by activation time. Owing to their large inner cavity and enclosed structure, HCNs are desirable carriers for encapsulating sulfur. To better understand the effects of pore characteristics and sulfur contents on the performances of lithium-sulfur batteries, three composites of HCNs and sulfur are prepared and studied in detail. The composites of HCNs with moderate specific surface areas and suitable sulfur content present a better performance. The first discharge capacity of this composite reaches 1401 mAh g at 0.2 C. Even after 200 cycles, the discharge capacity remains at 626 mAh g .