In recent years, there has been growing interest in developing high-performance, multifunctional ribbons for battery applications. In this study, we produced ultra-thin bimetallic ribbons (200–350 µm thick) of pure Al and pure Mg using single-roll melt spinning to form a layered Mg/Al structure. Key process parameters, including nozzle design and roll peripheral speed, were investigated via experiments and computational fluid dynamics (CFD) simulations. CFD analysis showed that a gradient-shaped nozzle reduced melt turbulence during co-flow of Mg and Al melt streams, improving Mg/Al interface formation. A diffusion layer formed at the Mg/Al interface, composed of Mg₁₇Al₁₂ and Mg₂Al₃ intermetallics as identified by electron probe micro-analysis (EPMA), is critical to the interfacial bonding in bimetallic ribbons. The thickness of this layer decreased with increasing roll speed, from 30.1 µm at 10 m/s to 4.5 µm at 20 m/s. These results were consistent with predictions from CFD analysis and DICTRA (DIffusion Controlled TRAnsformations) modeling, confirming that faster cooling rates at higher speeds limited diffusion layer growth. This work has established the feasibility of cladding dissimilar metals (Al and Mg) using a single-roll melt spinning process for battery applications.