Rational construction of spinel cobaltite/MXene composites towards superior interfacial charge dynamics for advanced pseudocapacitors

Abstract

The layered structure, large surface area, superior electrical conductivity, and outstanding chemical stability of MXenes make them attractive innovative electrode materials for supercapacitors. The incorporation of nanoparticles, particularly bi- and tri-metallic transition metal oxides, is commonly used to enhance the interlayer accessibility and improve the electrochemical performance. Among various MXenes, Nb₂CT_x stands out as an excellent candidate for supercapacitor applications because of its unique properties, which collectively facilitate rapid charge transport and efficient ion storage. A hydrothermal method was used in this work to fabricate a MgCo₂O₄/MXene nanocomposite. FTIR spectroscopy and XPS investigations revealed the chemical bonding, functional groups and various oxidation states, while XRD analysis confirmed the crystalline properties and phase uniformity of MgCo₂O₄/MXene. SEM coupled with EDX revealed irregular platelet-like nanoparticles distributed on the MXene layers and confirmed the elemental composition. The optimized electrode yielded an excellent specific capacitance of 1257.75 F g⁻¹ at 1 A g⁻¹ with a maximum cycling stability of 88.15% after 10 000 cycles. This research study illustrates a facile hydrothermal route for the synthesis of MXene-based nanocomposites with particles of controllable size for high-performance supercapacitor electrodes.