Nanotubes based composites rich in nitrogen for supercapacitor application

N-doped microporous carbon microspheres for high volumetric performance supercapacitors

“…Nevertheless, it should be noted that, despite a lower capacitance retention, the pristine N-doped microspheres still exhibit a better rate performance than many advanced carbons found in the literature such as threedimensionally hierarchical porous carbon [45], ordered mesoporous carbon nanopipes with nitrogen species [50], N-doped graphene sheets [51], N-rich carbon nanotubes composites [52] and N-doped carbon nanospheres [53]. The stability of the carbon microsphere-based supercapacitors was evaluated by long-term charge-discharge cycling at a current density of 5 A g -1 over 5000 cycles (Figure 5e).…”

Surface Modification of CNTs with N-Doped Carbon: An Effective Way of Enhancing Their Performance in Supercapacitors

“…13 _ENREF_13 Composites of CNTs and N-carbon obtained from polyacrylonitrile or melamine/formaldehyde have been prepared by Lota et al by physical mixing of both components, followed by carbonization. 14,15 For the former composites, surfacearea normalized capacitances of ~ 22 -32 μF cm -2 (2-electrode cell) were obtained for nitrogen contents of 7 -14 wt%, whereas for the latter surface-area normalized capacitances of ~ 24 -64 μF cm -2 (2-electrode cell) for N content ≥ 9.2 at%. Very recently, Jin and co-workers 16 and BaiGang and co-workers 17 followed a more complicated approach for the preparation of composites N-carbon/CNT, which is based on the carbonization of a N-rich polymer that has been previously coated onto the CNTs.…”

Carbon Nanotubes and Carbon Nanotubes/Metal Oxide Heterostructures: Synthesis, Characterization and Electrochemical Property

“…According to the mechanism of energy storage, ECs can be categorized into two classes [229]: (a) electrochemical double layer capacitors (EDLC), based on double-layer capacitance due to charge separation at the electrode/electrolyte interface, which thereby need materials with high specific surface area (e.g., activated carbon, CNTs), and (b) pseudocapacitors or supercapacitors, based on the pseudocapacitance of faradaic processes in active electrode materials such as transition metal oxides and conducting polymers. Because of their exceptional electronic properties, which allow ballistic transport of electrons over long nanotube lengths, CNTs have been considered a most promising candidate for electrochemical capacitors [230,231]. However, pure CNTs possess a rather low specific capacitance, typically about 10-40 F/g, which depends on the microtexture, purity, and electrolyte [231].…”

“…Because of their exceptional electronic properties, which allow ballistic transport of electrons over long nanotube lengths, CNTs have been considered a most promising candidate for electrochemical capacitors [230,231]. However, pure CNTs possess a rather low specific capacitance, typically about 10-40 F/g, which depends on the microtexture, purity, and electrolyte [231]. A considerable enhancement can be expected from the combination of CNTs with an electroactive material, which provides the additional pseudocapacitance while each tube acts as a minute electrode.…”