ELEktrode

Elektrode, in German, refers to an electrode, a conductor through which electric current enters or leaves a non-metallic medium, most often an electrolyte. Electrodes are essential components in a wide range of devices, including batteries, fuel cells, electroplating baths, and electrochemical sensors, where they mediate charge transfer at the interface between conductor and electrolyte.

In electrochemistry, two roles are defined: the anode, where oxidation occurs, and the cathode, where reduction occurs. In galvanic (discharge) cells the anode tends to be negative and the cathode positive; in electrolytic cells the polarities are reversed. Working electrodes are studied in experiments, while reference electrodes provide a stable potential against which measurements are made. Electrodes may be inert or active, depending on whether they participate in the chemical reaction at the interface.

Electrode materials vary by application. Common inert materials include platinum and graphite; active electrodes include metal or alloy electrodes used in batteries or plating baths. The electrode surface is often engineered to maximize area and tailor interfaces. The electrode–electrolyte interface forms a double layer that governs charge transfer and polarization, impacting efficiency and response time in devices.

Applications span energy storage and conversion (batteries, supercapacitors, fuel cells), electroplating, electroanalysis (such as voltammetry and potentiometry), and medical or industrial sensing. In welding, an electrode can also refer to a consumable wire or rod that conducts current and supplies filler metal to form a joint.