Lithium-ion batteries (LIBs) are ubiquitous in our portable electronics, however they are ill suited for applications where cost or sustainability are of paramount importance, e.g. load-leveling for renewable energy based grid storage. Sodium-ion batteries (NIB) have attracted interest for use in these applications, because of the high abundance and low-cost of sodium. While the chemistry of lithium and sodium are, to a first approximation, similar, the larger size of sodium throws up challenges for NIB technology. These include standardising the electrolyte – the ionic solution which is used to transfer ions between electrodes. In this experiment, we will use total scattering with isotopic substitution to probe the liquid structure of a common sodium-ion battery electrolyte as a function of concentration and temperature.