Theoretical investigation on the self-organized MXene heterostructures: interface, sliding and Li/Na ion storage application

MXene heterostructure compositions offer unique advantages by addressing self-stacking issues and increasing capacity simultaneously. The weak van der Waals (vdW) interaction between MXene heterostructures provides an excellent opportunity for engineering material properties. In this study, using Density Functional Theory (DFT) calculations, we focus on Ti3C2Tx/Nb2CTx heterostructures, discover a synchronous correlation between interlayer spacing and system energy during global sliding, with the distance between the nearest functional groups on opposite sides of the interlayer remaining almost constant, which we term the “decoupled interlayer correlation”. Based on this correlation, we investigate the potential applications of Ti3C2Tx/Nb2CTx 2D heterostructures in batteries and capacitors. Specifically, we perform calculations on 1-layer and 2-layer Li/Na intercalation, focusing on structural transformations and optimal capacities achievable through layer-sliding. Additionally, we explore Young’s moduli of ground-state configurations to characterize the elastic properties. These findings not only provide insights for further research on energy storage utilizing MXene heterostructures but also encourage exploration into sliding in other 2D systems that leverage vdW interactions.