Two-dimensional (2D) materials possess high aspect ratios, tuneable surface chemistry, high electrical conductivity and favourable mechanical properties, making them promising interfacial modifiers for composite systems. However, their tendency to aggregate, restack or lose effective contact with surrounding phases remains a key challenge. The central hypothesis of this thesis is that processing-controlled interfacial assembly can regulate three key interface-related factors: the spatial co-distribution of 2D materials and adjacent functional components, their interfacial contact or coupling, and the structural integrity of 2D nanosheets and constructed interfaces during processing and operation. Controlling these factors is expected to enable more load transfer, more stable conductive pathways and improved electrode integrity. To examine this hypothesis, three representative systems were investigated at different structural levels: reinforcement-matrix interfaces in aluminium matrix composites, active material-conductive network interfaces in conversion-type electrodes, and active material-textile scaffold in flexible electrodes.
First, Ti3C2Tx (MXene) was incorporated into aluminium matrices through electrostatic self-assembly followed by high-pressure torsion (HPT) processing. The surface terminations, layered morphology and mildly acidic assembly environment of MXene facilitated its attachment to aluminium powder surfaces, while HPT promoted further nanosheet dispersion and grain refinement. This combined strategy improved microstructural homogeneity and contributed to enhanced hardness and tensile performance.
Second, FeS2/reduced graphene oxide (rGO) composites were prepared through scalable ball milling of natural pyrite-derived FeS2 with rGO and evaluated as lithium- and sodium-ion battery electrodes. This process refined the FeS2 particles and promoted -IIIinterfacial
contact with rGO, enabling improved electronic connectivity, reduced charge-transfer resistance and enhanced cycling stability in both battery systems. In addition, the cycling-induced evolution of the composite structure, electrode thickness and charge-transfer resistance was analysed to clarify the origins of capacity fluctuation and fading.
Third, flexible electrodes were constructed by electrochemically reducing graphene oxide on textile scaffolds, followed by dip-coating FeS2/rGO active materials onto the conductive rGO-textile framework. The rGO-coated textile acted as a flexible conductive scaffold and interfacial mediator, improving active-layer adhesion, enabling high mass loading and maintaining electrochemical performance under bending and cycling.