Introduction: Other than in solutions or in ionic liquids, ionic conduction can take place in the solid state also. The solids that exhibit ionic conduction are called ‘solid-state ionic conductors’. Based on the charge of ionic species responsible for the conduction, they are divided into cationic and anionic conductors; then, based on specific species involved in the conduction, they are further subdivided into sodium ion conductors, proton conductors, fluorine ion conductors, and so on. Electrolytes in which the solid conductor is a polymer are more specifically referred to as polymer electrolytes (or ionomers). .
