Electrode

Electrode is a conductor through which electricity enters or leaves an object, substance, or region. They are used in a wide range of applications, including but not limited to, electronics, chemistry, and medicine.

Overview

An Electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). The word was coined by William Whewell at the request of the scientist Michael Faraday from two Greek words: elektron, meaning amber (from which the word electricity is derived), and hodos, a way.

Types of Electrodes

There are two types of electrodes: Anode and Cathode. The anode is positively charged, while the cathode is negatively charged.

Anode

The Anode is the electrode where oxidation (loss of electrons) takes place. In a galvanic cell, it is the negative electrode, as it is the electrode that provides electrons. In an electrolytic cell, it is the positive electrode.

Cathode

The Cathode is the electrode where reduction (gain of electrons) takes place. In a galvanic cell, it is the positive electrode, as it is the electrode that accepts electrons. In an electrolytic cell, it is the negative electrode.

Electrodes in Medicine

In medicine, electrodes are used in numerous ways, including in ECG machines to monitor heart activity, in EEG machines to monitor brain activity, and in ECT for treating mental disorders.

See Also

• Electrolysis
• Electrochemical cell
• Battery
• Fuel cell
• Electrode potential
• Standard electrode potential

References

• Arc welding electrodes and electrode holder
  Arc welding electrodes and electrode holder
• Galvanic cell with no cation flow
  Galvanic cell with no cation flow
• Batteries
  Batteries
• Rechargeable batteries
  Rechargeable batteries
• Battery discharge and charge
  Battery discharge and charge
• Hush adiabatic electron transfer model parameters
  Hush adiabatic electron transfer model parameters
• Redox flow battery
  Redox flow battery