Ni 0.9 Co 1.92 Se 4 nanostructures: binder-free electrode of coral-like bimetallic selenide for supercapacitors

• Published in: RSC advances Vol. 6; no. 79; pp. 75251 - 75257
• Main Authors: An, Weidan, Liu, Ling, Gao, Yanfang, Liu, Yang, Liu, Jinrong
• Format: Journal Article
• Language: English
• Published: 2016
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C6RA17825A

Coral-like Ni 0.9 Co 1.92 Se 4 nanostructured materials have been prepared through a simple and controlled two-step solvothermal method, which present a handsome electrochemical performance. The specific capacitance reaches 1021.1 F g −1 under the current density of 2 mA cm −2 over a 0.5 V electrode potential window with an areal capacitance of 6.43 F cm −2 . A superior rate capability of 77% is achieved with discharge rates increasing from 2 to 50 mA cm −2 , as well as a good cycling stability of 88.39% after 5000 cycles. Furthermore, a good energy density of 26.29 W h kg −1 is achieved under the power density of 265 W kg −1 when assembled into a Ni 0.9 Co 1.92 Se 4 //AC asymmetric supercapacitor with the operating potential window extended to 1.5 V. The high performance can be attributed to the coral-like architectures with rich redox reactions, high conductivity and transport rate for both electrons and electrolyte ions. Our results suggest that the coral-like Ni 0.9 Co 1.92 Se 4 nanostructured electrode materials may be a good choice for supercapacitors.