As per the definition of electrode, it is any substance that is a good conductor of electricity and these substances usually connect nonmetallic parts of a circuit for example semiconductors, an electrolyte, plasmas, vacuum or even air. The term was first coined by William Whewell and derived from Greek words elektron, which means “amber” and hodos which translates to “a way.” An early version of an electrode was electrophore which was used to study static electricity. It was invented by Johan Wilcke. To help you understand the concept in simple terms, an electrode is a point where current enters and leaves the electrolyte. Notably, an electrode does not necessarily have to metals.
When studying electrodes, there are few things that we come across. The two common terms we hear is cathode and anode. Cathode is the current that leaves the electrodes or cathode is a result of reduction reaction taking place in an electrolyte mixture. Here electrons are released from the electrode and the solution around it is reduced. Whereas when the current enters during oxidation reaction it is known as the anode. As such, electrodes are vital components in electrochemical cells as they transport produced electrons from one half-cell to another, which results in the production of an electrical charge.
Types and Examples of Electrodes
Here we will look at some of the examples of electrodes. There are mainly two types of electrodes namely reactive and inert electrodes. An inert type does not participate in any reaction while reactive types participate actively in reactions. Some commonly used inert electrodes include platinum, gold,graphite(carbon), and rhodium. Some of the reactive electrodes include zinc, copper, lead, and silver.
Uses of Electrodes
The main use of electrodes are to generate electrical current and pass it through nonmetal objects to basically alter them in several ways. Electrodes are also used to measure conductivity. Some of the other uses include:
Electrodes are used in different battery types, electroplating and electrolysis, welding, cathodic protection, membrane electrode assembly, for chemical analysis, and Taser electroshock weapon. In the medical field, electrodes are also used in ECG, ECT, EEG, and defibrillator. Electrodes are further used for electrophysiology techniques in biomedical research.
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