Premium
Structurally Stable Mesoporous Hierarchical NiMoO 4 Hollow Nanofibers for Asymmetric Supercapacitors with Enhanced Capacity and Improved Cycling Stability
Author(s) -
Sudheendra Budhiraju Venkata,
Sharma Ashutosh,
Sivakumar Sri
Publication year - 2017
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201700503
Subject(s) - nanofiber , mesoporous material , supercapacitor , materials science , anode , electrospinning , cathode , chemical engineering , specific surface area , current density , electrolyte , power density , nanotechnology , electrochemistry , carbon nanofiber , electrode , carbon nanotube , composite material , chemistry , catalysis , polymer , biochemistry , physics , engineering , power (physics) , quantum mechanics
Herein, we report, for the first time, the facile synthesis of four different mesoporous hierarchical structures of NiMoO 4 through electrospinning: solid nanofibers, porous nanofibers, hollow nanofibers, and microplates of NiMoO 4 . All of these structures were investigated as electrode materials for supercapacitors. Amongst these, hollow NiMoO 4 nanofibers demonstrated superior electrochemical performance with a high specific capacity of 214 mAh g −1 (1920 F g −1 ) at a current density of 2 A g −1 and a capacity retention of 92 % after 3000 cycles. An asymmetric supercapacitor fabricated from a hollow NiMoO 4 nanofiber cathode and an activated carbon anode displayed a high specific capacity of 49 mAh g −1 (110 F g −1 ) at a current density of 1 A g −1 and a capacity retention of 97 % after 5000 cycles. At this current density, the device delivered a high energy density of 39 Wh Kg −1 and a power density of 798 W Kg −1 at a relatively high mass loading of 5 mg cm −2 of active material on the substrate. This impressive performance of hollow NiMoO 4 nanofibers could be attributed to their mesoporous surface with high specific surface area (ca. 105 m 2 g −1 ), the hollow core and the interconnectedness of the fibers that improve the electrolyte penetration, increase the rate of the surface redox reactions and allow for faster transport of the charges.