électrolyte

An electrolyte is a substance that dissociates into ions when dissolved in a solvent, producing an electrically conducting solution. In French contexts, the term is électrolyte. In solid form many electrolytes do not conduct; dissolution or melting enables ion mobility. Common electrolytes include salts (sodium chloride), strong acids (hydrochloric acid), and strong bases (sodium hydroxide).

Electrolytes are classified by their degree of dissociation: strong electrolytes dissociate completely (e.g., NaCl, HCl, KOH), weak electrolytes dissociate partially (acetic acid, ammonium hydroxide), and non-electrolytes (glucose, urea) do not form significant ions and do not conduct electricity.

In biology, electrolytes are essential for osmotic balance, nerve function, and muscle activity. Major bodily ions include sodium (Na+), potassium (K+), chloride (Cl-), calcium (Ca2+), bicarbonate (HCO3-), and phosphate (HPO4^2-). Imbalances are common in disease or dehydration and are treated with electrolyte solutions.

In chemistry and engineering, electrolytes serve as ion conductors in electrochemical cells and electrolytic processes. They can be aqueous or molten; conductivity increases with ion concentration and mobility. In energy storage, electrolytes enable ion transport in batteries and supercapacitors, and in electroplating and electrolysis they complete the circuit.