Electrodes can be defined as conductors that are used to make electrical contact with a non-metallic part of the circuit. 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 earlier version of an electrode was the 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 the current enters and leaves the electrolyte. Notably, an electrode does not necessarily have to be metals.
When studying electrodes, there are a few things that we come across. The two common terms we hear is cathode and anode. The 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 surrounding solution is reduced.
Here we will look at some examples of electrodes.
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.
The main use of electrodes is to generate electrical current and pass it through non-metal objects to basically alter them in several ways. Electrodes are also used to measure conductivity. Some 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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