Electrochromic materials typically consist of a thin film of nanostructured material, such as tungsten oxide (WO3) or niobium oxide (Nb2O5), deposited on a conductive substrate. When a voltage is applied, ions (usually lithium or hydrogen ions) move into or out of the nanostructured film, causing a change in its oxidation state. This ion insertion/extraction process modulates the material's optical properties, leading to a visible change in color.
