1. Electrolyte solutions

1.1 Context

An electrolyte is a chemical substance which, by definition, conducts electricity through its dissociation into cations (positively charged ions) and anions (negatively charged ions), and the movement of the latter. Most electrolytes are solid at room temperature: we call them solid salts. At high temperatures, these salts can dissociate and melt: molten salts such as sodium nitrate (NaNO ₃ ) can be used as heat transfer fluids or as phase-change materials in thermal energy storage. There are other types of solid electrolyte, such as nafion polymer or solid oxides, which are used in certain types of fuel cells and electrolyzers.

Some electrolytes can be liquid and partially dissociated at room temperature...