This book serves as a comprehensive guide for both beginners and researchers, offering insights into the diverse array of electrochemical devices and their intricate dependencies. It provides a comprehensive overview of electrochemical devices from fundamental principles to cutting-edge applications. By bringing together insights from materials science, chemistry, physics, engineering, and beyond, it offers a holistic understanding of the underlying mechanisms, design strategies, and practical considerations associated with these devices. The book begins by exploring of the fundamental principles of electrochemistry, laying the groundwork for understanding electrochemical reactions, charge transfer processes, and device operation mechanisms. Building upon this foundation, it delves into various types of electrochemical devices, including solar cells, photodetectors, sensors, batteries, and more.