Preparation and performance of rose stalk-like niobium nitride nanofibers for supercapacitor

• Published in: Journal of materials science. Materials in electronics Vol. 33; no. 27; pp. 21384 - 21395
• Main Authors: Xu, Kaizheng, Cui, Shuai, Liu, Suyun, Lv, Dongfeng, Hu, Shilei, Cui, Yi, Chen, Yuejun, Wei, Yingna, Wei, Hengyong
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2022; Springer Nature B.V
• Subjects: Ammonia; Carbon; Characterization and Evaluation of Materials; Chemistry and Materials Science; Electrochemical analysis; Electrode materials; Electrodes; Electrolytes; Energy storage; Ethanol; Glycerol; Materials Science; Nanofibers; Niobium nitride; Optical and Electronic Materials; Solid solutions; Supercapacitors; Valence
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-022-08931-1

Rose stalk-like Nb 4 N 5 fibers were prepared by electrospinning, solvothermal method and ammonia reduction technology. The composition and morphology were characterized. The results showed that the corresponding XRD (X-ray diffractometer) pattern of the sample was indexed to tetragonal Nb 4 N 5 , and it existed as NbN x O 1− x solid solution, in which Nb ions exist in the form of + 3 and + 5. The abundant valence states made Nb ions undergo reversible proton insertion/chemical adsorption in the conductive channels of the Nb 4 N 5 nanofibers. The Nb 4 N 5 nanofibers presented a rose stalk-like structure, and thus its specific surface area was high to 76.42 m 2  g −1 with pore diameter of 13.2 nm. The specific capacitance of the Nb 4 N 5 ||Nb 4 N 5 symmetric supercapacitor device reached to 139.03 F g −1 at the current density of 10 mA g −1 . When the energy density was 12.60 Wh kg −1 , the power density of the supercapacitors was 2.16 kW kg −1 . It was indicated that the rose stalk-like structure gave the Nb 4 N 5 nanofibers a larger contact area which was conducive to the construction of a conductive network, and thus the electron transmission rate was improved, thereby improving the electrochemical performance of the Nb 4 N 5 fibers electrode materials for supercapacitors.