Heterostructured Nanocomposites of NiCo–S@Ni(OH)2 on Ni Foam for High-Performance Supercapacitors

The development of composite materials is a key area of research for enhancing the electrochemical performance of electrode materials. In this study, NiCo–S nanostructured hybrid electrode materials were prepared on nickel foam (NF) by using binary metal–organic frameworks (MOFs) as the sacrificial template through a two-step hydrothermal method. Ni–MOF was then deposited on the surface of NiCo–S/NF through the hydrothermal method and subsequently converted into Ni(OH) 2 through a subsequent alkalization treatment. The duration of the Ni–MOF hydrothermal process was varied as a parameter. NiCo–S@Ni–MOF/NF was prepared through hydrothermal reaction for 6 h, 9 h and 12 h, followed by heating in a 6 M KOH solution at 75 ∘ C for 6 h in a water bath. The electrode materials with the best morphology and electrochemical properties were obtained when the hydrothermal reaction time was 6 h. The optimized electrode had a specific capacity of 2533.2 F ⋅ g − 1 at 1 A ⋅ g − 1 and a capacity retention rate of 60.8% at 10 A ⋅ g − 1 , which indicated good rate performance. Additionally, the electrode material demonstrated excellent cycling stability, with a capacity retention rate of 95.3% after 5000 cycles at 50 mV ⋅ s − 1 . The energy density of the hybrid supercapacitor device assembled from this electrode material was 33.5 Wh ⋅ kg − 1 when the power density was 849.89 W ⋅ kg − 1 at a current density of 1 A ⋅ g − 1 .