2D/2D interface engineering of NiCrFe-layered double hydroxide-MXene hybrid architecture for extrinsic supercapacitors

The mesoporous hybrid architecture of MXene and NiCrFe-layered double hydroxide (NCF-LDH) can significantly enhance the electrochemical performance of pristine NCF-LDH. In this study, a NiCrFe-LDH-MXene (NCFM) hybrid structure is synthesized through the self-assembly of exfoliated NCF-LDH and MXene nano- sheets. The 2D/2D NCFM hybrid architecture displays expanded surface area, interconnected porous morphology, and intimate coupling between nanosheets. This unique architecture, along with strong interfacial interactions and synergistic effects between MXene and NCF-LDH nanosheets, greatly improves electrical conductivity and increases the number of active sites accessible to electrolytes. Moreover, the hybrid architecture prevents self-aggregation and restacking of the NCF-LDH and MXene nanosheets, ensuring full exposure of the active sites. Due to this unique 2D/2D hybrid architecture, the NCFM hybrid demonstrates an excellent specific capacity of 1082C g(-1) at a current density of 1 A g(-1). Furthermore, the solid-state supercapacitor constructed using NCF-LDH as the battery-type electrode and activated carbon as the capacitive electrode achieves a notable energy density of 62 Wh kg(-1) at a power density of 0.8 kW kg(-1). Additionally, the supercapacitor exhibits an outstanding capacitance retention rate of 86 % after 11,000 cycles at 8 A g(-1). These exceptional findings encourage further investigation into such promising 2D/2D hybrid structures with excellent charge storage capabilities and microstructural characteristics for developing next-generation energy storage systems.