MOF-Derived Ultrathin NiCo-S Nanosheet Hybrid Array Electrodes Prepared on Nickel Foam for High-Performance Supercapacitors
Jing Li, Jing Li, Jun Li, Jun Li, Meng Shao, Yanan Yan, Ruoliu Li
Abstract
At present, binary bimetallic sulfides are widely studied in supercapacitors due to their high conductivity and excellent specific capacitance (SC). In this article, NiCo-S nanostructured hybrid electrode materials were prepared on nickel foam (NF) by using a binary metal–organic skeleton as the sacrificial template via a two-step hydrothermal method. Comparative analysis was carried out with Ni-S and Co-S in situ on NF to verify the excellent electrochemical performance of bimetallic sulfide as an electrode material for supercapacitors. NiCo-S/NF exhibited an SC of 2081 F∙g−1 at 1 A∙g−1, significantly superior to Ni-S/NF (1520.8 F∙g−1 at 1 A∙g−1) and Co-S/NF (1427 F∙g−1 at 1 A∙g−1). In addition, the material demonstrated better rate performance and cycle stability, with a specific capacity retention rate of 58% at 10 A∙g−1 than at 1 A∙g−1, and 75.7% of capacity was retained after 5000 cycles. The hybrid supercapacitor assembled by NiCo-S//AC exhibited a high energy density of 25.58 Wh∙kg−1 at a power density of 400 W∙kg−1.