Why do ionic solids conduct electricity poorly but conduct when melted or dissolved?

Ionic solids are poor electrical conductors because their constituent ions are locked into a rigid, ordered crystalline lattice. In this solid state, the ions are held in fixed positions by strong electrostatic forces, meaning they lack the mobility required to carry an electric current.123

However, when an ionic solid is melted or dissolved in a solvent like water, the lattice structure breaks down, allowing the ions to move freely. This process, known as dissociation, creates an electrolyte solution or melt. When an electrical potential is applied, these charged particles can migrate toward the electrodes of opposite polarity, effectively carrying the electric current through the substance.45

While some solids can conduct electricity through a process called ion hopping, this is generally negligible compared to the conductivity provided by the free-moving ions found in molten or dissolved states.65