A binder-free NiCo2O4 nanosheet/3D elastic N-doped hollow carbon nanotube sponge electrode with high volumetric and gravimetric capacitances for asymmetric supercapacitors.

Content Provider	Semantic Scholar
Author	Tong, Hao Yue, Shihong Lu, Liang Jin, Fengqiao Han, Qiwei Zhang, Xiaogang Liu, Jiyan
Copyright Year	2017
Abstract	To increase the volumetric and gravimetric capacitances of supercapacitors, a new class of electrode materials with high electrochemical activity and favorable structures is extremely desired. In this work, a hollow novel nitrogen-doped 3D elastic single-walled carbon nanotube sponge (NSCS) which is ultra lightweight with the lowest density of 0.8 mg cm-3, and has a high open surface structure for electrolyte accessibility and excellent compressible properties as the electrode scaffold has been successfully fabricated by the pyrolysis method which could produce the carbon nanotube sponge easily on a large scale without high-cost and time-consuming processes. Moreover, a NiCo2O4 nanosheet supported on the NSCS has been successfully fabricated. The highest volumetric and gravimetric capacitance of this electrode is 790 F cm-3 at 1.43 g cm-3 and 1618 F g-1 at 0.54 g cm-3 with excellent cycling stability. The density of NiCo2O4/NSCS electrode was adjusted by mechanical compression and the most favorable density of the film for both high volumetric and gravimetric capacitances obtained was 1.21 g cm-3. The thick NiCo2O4/NSCS film of 72 μm has been fabricated at this favorable density, presenting both high volumetric and gravimetric capacitances of 597 F cm-3 and 1074 F g-1 at 1 A g-1, respectively, indicating that the structure of the NSCS is extremely feasible for obtaining a thick film electrode with excellent volumetric and gravimetric capacitances. Furthermore, an asymmetric supercapacitor of NiCo2O4/NSCS//NGN/CNTs was fabricated, exhibiting a high gravimetric energy density of 47.65 W h kg-1 at 536 W kg-1 and a volumetric energy density of 33.44 W h L-1 at 376.16 W L-1.
Starting Page	16826
Ending Page	16835
Page Count	10
File Format	PDF HTM / HTML
DOI	10.1039/c7nr02498c
PubMed reference number	29072743
Journal	Medline
Volume Number	9
Issue Number	43
Alternate Webpage(s)	http://www.rsc.org/suppdata/c7/nr/c7nr02498c/c7nr02498c1.pdf
Alternate Webpage(s)	https://doi.org/10.1039/c7nr02498c
Journal	Nanoscale
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article