An electrolyte is an element or compound that, when dissolved or melted in water or other solvent, dissociates into ions and is able to conduct an electric current, as in electrolysis. In a lead-acid car battery, for example, the electrolyte is dilute sulfuric acid, which contains negative sulfate ions and positive hydrogen ions. Seawater is the commonest natural electrolyte in the world, and by suspending a zinc and a steel sheet in it, a little electricity can be produced.
Electrolytes and life
Electrolytes differ in their concentrations in blood plasma, interstitial fluid, and cell fluid and affect the movement of substances between those compartments. Proper quantities of principal electrolytes and balance among them are critical to normal metabolism and function.