Minimizing Intersheet Junction Resistivity via Au4Cu2 Nanocluster-Based Connectivity in Mo2TiC2 MXene for Symmetric Supercapacitor Device

Abstract

MXenes with their intrinsic metallic conductivity and redox versatility have emerged as frontrunners in the search for advanced energy storage materials. However, their energy storage capabilities are often hindered by the limited accessibility of electrolytes to active sites and enhanced electrical resistance due to the susceptibility to layer restacking. To address these challenges, a novel, ultrasmall Au4Cu2 nanocluster, strategically embedded within Mo2TiC2 MXene layers, is introduced. This integration is facilitated through precise interfacial local interactions, which govern the regulation of interlayer electron flow. The Au4Cu2 nanocluster modifies the local electron density, promoting a gradient in electronic conductivity throughout the MXene layers and acting as a nanoscopic bridge that counters the tendency for restacking. This approach markedly enhances the charge transfer efficiency and, consequently, the charge storage capacity. The nanoclusters/MXene composite-based symmetric supercapacitor provides superior energy density and power density. The findings reveal a sophisticated interface engineering strategy for the prevention of interlayer restacking of MXenes that significantly elevates their ability to store charge.