Optimizing hybrid supercapacitor performance through synergistic integration of metal–organic frameworks and metal oxides

Metal-organic frameworks (MOFs) offer significant advantages for energy storage, including high surface area, customizable porosity, and abundant active sites. We utilized these properties to synthesize a novel barium-MOF and neodymium oxide composite (Ba-MOF/Nd₂O₃) as an electrode material for hybrid supercapacitors. Incorporating Nd₂O₃-a lanthanide-series rare-earth metal oxide-enhances the composite's electrochemical properties, particularly in terms of specific capacity, energy density, power density, and cyclic stability. In a half-cell setup, the composite provided a remarkable specific capacity of 718 C g^-1 at the lowest current density (1.9 A g^-1). For further investigation, a real device was functionalized, which provided better energy density of 96 Wh kg^-1 with a maximum power density of 9350 W kg^-1. The device exhibited a rate capability of 96% and capacity retention of 92%, even after the 5000 charge-discharge process. Furthermore, semi-empirical models were employed to assess the capacitive and diffusive contributions.