Electrodes are essential components in various electrochemical devices, such as batteries, capacitors, and fuel cells. They are conductive materials that facilitate the flow of electrical current in and out of the device. In a battery, for example, the anode (negative electrode) and cathode (positive electrode) are where oxidation and reduction reactions occur, respectively. These reactions enable the transfer of ions through the electrolyte, generating electrical energy. Electrodes are typically made from materials like metals, carbon, or composite materials, chosen for their conductivity, stability, and compatibility with the electrolyte. In capacitors, electrodes store and release electrical charge, while in fuel cells, they facilitate the conversion of chemical energy into electrical energy. The design and material of electrodes significantly impact the performance, efficiency, and lifespan of electrochemical devices.