2D Material-Based Flexible Electrochromic Devices

Electrochromic devices (ECDs) are emerging as potential candidates for energy-efficient and visually adaptive technologies. A notable shift in the materials’ color results from the application of electric fields to particular electrochromic (EC) materials, which alter the materials’ ability to absorb or transmit light through electrochemical reactions. Due to their simple structure, low power consumption, and multicolor capabilities, ECDs have shown great promise in the fields of smart windows, displays, smart clothing, energy storage, and future wearable electronics. The advantages of ECDs over other color-change mechanisms, like thermochromism and photochromism, include their ability to display multiple colors, high contrast, quick color changes, low energy consumption, lack of blind visual angles, and ability to maintain color after powering off. These features give ECDs a promising future for the Internet of Things (IoT) and Industrial 4.0. When J. R Platt was researching organic dyes in 1961, he made the initial discovery of the EC effect. Redox reactions between the intercalated ions and the electrode material, which occur at the electrode material’s near surface when a voltage is applied, typically less than 3 V, are the main cause of EC behavior. However, restricted flexibility, low coloring efficiency, and long response times of 3D materials have made it difficult to use them for practical applications. One possible way to address these issues is to utilize two-dimensional (2D) materials, which have outstanding conductivity, flexibility, transparency, and fast ion diffusion. This chapter discusses 2D materials utilized in electrochromic devices.