An advanced hybrid supercapacitor constructed from rugby-ball-like NiCo2Se4 yolk–shell nanostructures

• Published in: Materials chemistry frontiers 2021-06, Vol.5 (12), p.4725-4738
• Main Authors: Ameri, Bahareh, Akbar Mohammadi Zardkhoshoui, Saied Saeed Hosseiny Davarani
• Format: Article
• Language: English
• Subjects: Activated carbon; Cathodes; Electrical resistivity; Electrochemical analysis; Electrode materials; Electrodes; Energy storage; Nanostructure; Rugby; Shells (structural forms); Supercapacitors
• ISSN: 2052-1537
• DOI: 10.1039/d1qm00349f

Electrode materials based on the yolk–shell structure are of considerable importance in the energy-storage field. Herein, rugby-ball-like NiCo2Se4 yolk–shell nanostructures (RB-NCS) are successfully synthesized and developed as an attractive cathode electrode material for hybrid supercapacitors. Benefiting from the high porosity of the obtained structure and desirable electrical conductivity, the as-designed RB-NCS electrode presents a prominent capacity of 258.1 mA h g−1 at 1 A g−1 and an impressive longevity of 92.2% over 14 000 cycles at 20 A g−1; meanwhile, a high coulombic efficiency of ≈98.1% is achieved. Considering the achieved excellent results, a hybrid supercapacitor was fabricated with the RB-NCS and AC (activated carbon) materials as the cathode and anode electrodes, respectively, in KOH electrolyte (6 M). The as-fabricated apparatus (RB-NCS(+)||AC(−)) delivered a desirable capacity of 71 mA h g−1 at 1 A g−1 with a good capacity retention of 68.9%. Also, the RB-NCS(+)||AC(−) apparatus reflected maximum energy and power densities of 56.9 W h kg−1 and 812.6 W kg−1 at 1 A g−1, respectively.