We will use X-ray pair distribution function (XPDF) at ESRF ID15A to resolve local structure in aqueous zinc acetate electrolytes modified with potassium acetate (co-salt) or acetonitrile (co-solvent). For the potassium acetate series, we will quantify how zinc coordination, ion pairing, and clustering evolve with composition and hydration, and relate these motifs to conductivity, zinc-ion transference, and plating behavior. For the acetonitrile series, we will measure bulk solutions and cloud-point compositions; under applied bias we will collect spatially resolved XPDF across the cell to track phase separation and local structural rearrangement. XPDF will provide sub-ångström real-space resolution, enabling extraction of short- and medium-range order. The resulting local structure–property relationships will guide electrolyte designs that stabilize zinc metal anodes and mitigate hydrogen evolution.