Hierarchical copper cobalt sulfides nanowire arrays for high-performance asymmetric supercapacitors

• Published in: Applied surface science Vol. 487; pp. 198 - 205
• Main Authors: Du, Jialiang, Yan, Qing, Li, Yiju, Cheng, Kui, Ye, Ke, Zhu, Kai, Yan, Jun, Cao, Dianxue, Zhang, Xianfa, Wang, Guiling
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2019
• Subjects: CuCo2S4; High energy density; Nanowire array; Sulfidation; Supercapacitor; Supercapacitor; Sulfidation; High energy density; Nanowire array; CuCo2S4
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2019.04.275

Binary transition metal sulfides are considered to be promising electrode materials for high-performance supercapacitors because of their ultrahigh electron conductivity and superior electrochemical activity compared to the unitary transition metal sulfides. In this work, copper cobalt sulfides nanowire arrays on nickel foam with different element ratios and porosities are prepared by using a two-step hydrothermal method, and their electrochemical performance is explored. Benefited from the high electrical conductivity, rich active sites and optimized microstructure, the optimized copper cobalt sulfides (CuCo2S4) electrode can achieve a ultrahigh specific capacitance of 2446.6 F·g−1 at 1 A·g−1 and favorable rate performance. The asymmetric supercapacitor assembled with the CuCo2S4 nanowire array and activated carbon (AC) electrodes displays a high energy density of 33.4 Wh·kg−1 at a power density of 751.5 W·kg−1 can be obtained. Additionally, the assembled asymmetric cell shows a favorable capacitance retention of 78% after charging and discharging for 10,000 cycles at a high current density of 4 A·g−1. •The CuCo2S4 electrode achieves an ultrahigh specific capacitance of 2446 F·g−1 at 1 A·g−1.•The CuCo2S4 electrode has unique microstructure and exhibits good rate performance.•The CuCo2S4/AC-ASC displays high energy density of 33.4 Wh·kg−1 at power density of 751.5 W·kg−1.