In situ preparation of MgCo2O4 nanosheets on Ni-foam as a binder-free electrode for high performance hybrid supercapacitors

Abstract

A binder-free, MgCo₂O₄ nanosheet-like architecture was prepared on Ni-foam using a hydrothermal method. MgCo₂O₄/Ni-foam was characterized by X-ray diffraction, field emission scanning electron microscopy (FESEM), and transmission electron microscopy techniques. The FESEM image revealed a nanosheet array-like architecture. The MgCo₂O₄ nanosheets grown on Ni-foam exhibited the maximum specific capacity of 947 C g⁻¹ at a specific current of 2 A g⁻¹. Approximately 96% of the specific capacity was retained from the maximum specific capacity after 5000 continuous charge–discharge cycles. This hybrid device exhibited a maximum specific capacity of 52 C g⁻¹ at a specific current of 0.5 A g⁻¹, and also exhibited a maximum specific energy of 12.99 W h kg⁻¹ at a specific power of 448.7 W kg⁻¹. These results confirmed that the binder-free MgCo₂O₄ nanosheets grown on Ni-foam are a suitable positive electrode material for hybrid supercapacitors.