Arabic Bulgarian Chinese Croatian Czech Danish Dutch English Estonian Finnish French German Greek Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Korean Latvian Lithuanian Malagasy Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swedish Thai Turkish Vietnamese
Arabic Bulgarian Chinese Croatian Czech Danish Dutch English Estonian Finnish French German Greek Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Korean Latvian Lithuanian Malagasy Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swedish Thai Turkish Vietnamese

definitions - Anode

anode (n.)

1.a positively charged electrode by which electrons leave an electrical device

2.the negatively charged terminal of a voltaic cell or storage battery that supplies current

Anode (n.)

1.(MeSH)Mediums used between an electric conductor and the object to which the current is to be applied. In electrotherapy, electrodes are instruments with a point or surface from which to transmit electric current to the body of a patient or to another instrument; in electrodiagnosis, they are needles or metal plates used to stimulate or record the electrical activity of tissue. (From Dorland, 28th ed)

   Advertizing ▼

Merriam Webster

AnodeAn"ode (�), n. [Gr. � up + � way.] (Elec.) The positive pole of an electric battery, or more strictly the electrode by which the current enters the electrolyte on its way to the other pole; -- opposed to cathode.

   Advertizing ▼

definition (more)

definition of Wikipedia

synonyms - Anode

Anode (n.) (MeSH)

Cathode  (MeSH), Electrodes  (MeSH)

see also - Anode

anode (n.)

anodal, anodic cathode


analogical dictionary



  Diagram of a zinc anode in a galvanic cell. Note how electrons move out of the cell, and the conventional current moves into it in the opposite direction.

An anode is an electrode through which electric current flows into a polarized electrical device. The direction of electric current is, by convention, opposite to the direction of electron flow. In other words, the electrons flow from the anode into, for example, an electrical circuit. Mnemonic: ACID (Anode Current Into Device).

A widespread misconception is that anode polarity is always positive (+). This is often incorrectly inferred from the correct fact that in all electrochemical devices negatively charged anions move towards the anode (hence their name) and positively charged cations move away from it. In fact anode polarity depends on the device type, and sometimes even in which mode it operates, as per the above electric current direction-based universal definition. Consequently, as can be seen from the following examples, in a device which consumes power the anode is positive, and in a device which provides power the anode is negative:

  • In a discharging battery or galvanic cell (diagram at right) the anode is the negative terminal since that is where the current flows into the device (see drawing). This inward current is carried externally by electrons moving outwards, negative charge moving one way constituting positive current flowing the other way. It is continued internally by positive ions flowing into the electrolyte from the anode, i.e., away (surprisingly) from the more negative electrode and towards the more positive one (chemical energy is responsible for this "uphill" motion).
  • In a recharging battery, or an electrolytic cell, the anode is the positive terminal, which receives current from an external generator. The current through a recharging battery is opposite to the direction of current during discharge; In other words, the electrode which was the cathode during battery discharge becomes the anode while the battery is recharging.
  • In a diode, it is the positive terminal at the tail of the arrow symbol, where current flows into the device. Note electrode naming for diodes is always based on the direction of the forward current (that of the arrow, in which the current flows "most easily"), even for types such as Zener diodes or solar cells where the current of interest is the reverse current.
  • In a cathode ray tube, it is the positive terminal where electrons flow out of the device, i.e., where positive electric current flows in.

An electrode through which current flows the other way (out of the device) is termed a cathode.



The word was coined in 1834 from the Greek ἄνοδος (anodos), 'ascent', by William Whewell, who had been consulted[1] by Michael Faraday over some new names needed to complete a paper on the recently discovered process of electrolysis. In that paper Faraday explained that when an electrolytic cell is oriented so that electric current traverses the "decomposing body" (electrolyte) in a direction "from East to West, or, which will strengthen this help to the memory, that in which the sun appears to move", the anode is where the current enters the electrolyte, on the East side: "ano upwards, odos a way ; the way which the sun rises" (,[2] reprinted in [3]).

The use of 'East' to mean the 'in' direction (actually 'in' → 'East' → 'sunrise' → 'up') may appear contrived. Previously, as related in the first reference cited above, Faraday had used the more straightforward term "eisode" (the doorway where the current enters). His motivation for changing it to something meaning 'the East electrode' (other candidates had been "eastode", "oriode" and "anatolode") was to make it immune to a possible later change in the direction convention for current, whose exact nature was not known at the time. The reference he used to this effect was the Earth's magnetic field direction, which at that time was believed to be invariant. He fundamentally defined his arbitrary orientation for the cell as being that in which the internal current would run parallel to and in the same direction as a hypothetical magnetizing current loop around the local line of latitude which would induce a magnetic dipole field oriented like the Earth's. This made the internal current East to West as previously mentioned, but in the event of a later convention change it would have become West to East, so that the East electrode would not have been the 'way in' any more. Therefore "eisode" would have become inappropriate, whereas "anode" meaning 'East electrode' would have remained correct with respect to the unchanged direction of the actual phenomenon underlying the current, then unknown but, he thought, unambiguously defined by the magnetic reference. In retrospect the name change was unfortunate, not only because the Greek roots alone do not reveal the anode's function any more, but more importantly because, as we now know, the Earth's magnetic field direction on which the "anode" term is based is subject to reversals whereas the current direction convention on which the "eisode" term was based has no reason to change in the future.

Since the later discovery of the electron, an easier to remember, and more durably correct technically although historically false, etymology has been suggested: anode, from the Greek anodos, 'way up', 'the way (up) out of the cell (or other device) for electrons'.

  Flow of electrons

The flow of electrons is always from anode to cathode outside of the cell or device, regardless of the cell or device type and operating mode, with the exception of diodes, where electrode naming always assumes current in the forward direction (that of the arrow symbol), i.e., electrons flow in the opposite direction, even when the diode reverse-conducts either by accident (breakdown of a normal diode) or by design (breakdown of a Zener diode, photo-current of a photodiode or solar cell).

  Electrolytic anode

In electrochemistry, the anode is where oxidation occurs and is the positive polarity contact in an electrolytic cell. At the anode, anions (negative ions) are forced by the electrical potential to react chemically and give off electrons (oxidation) which then flow up and into the driving circuit. Mnemonics: LEO Red Cat (Loss of Electrons is Oxidation, Reduction occurs at the Cathode), or AnOx Red Cat (Anode Oxidation, Reduction Cathode), or OIL RIG (Oxidation is Loss, Reduction is Gain of electrons), or Roman Catholic and Orthodox (Reduction - Cathode, anode - Oxidation), or LEO the lion says GER (Losing electrons is Oxidation, Gaining electrons is Reduction)

This process is widely used in metals refining. For example, in copper refining, copper anodes, an intermediate product from the furnaces, are electrolysed in an appropriate solution (such as sulfuric acid) to yield high purity (99.99%) cathodes. Copper cathodes produced using this method are also described as electrolytic copper.

  Battery or galvanic cell anode

In a battery or galvanic cell, the anode is the negative electrode from which electrons flow out towards the external part of the circuit. Internally the positively charged cations are flowing away from the anode (even though it is negative and therefore would be expected to attract them, this is due to electrode potential relative to the electrolyte solution being different for the anode and cathode metal/electrolyte systems); but, external to the cell in the circuit, electrons are being pushed out through the negative contact and thus through the circuit by the voltage potential as would be expected. Note: in a galvanic cell, contrary to what occurs in an electrolytic cell, no anions flow to the anode, the internal current being entirely accounted for by the cations flowing away from it (cf drawing).

In the United States, many battery manufacturers regard the positive electrode as the anode, particularly in their technical literature. Though technically incorrect, it does resolve the problem of which electrode is the anode in a secondary (or rechargeable) cell. Using the traditional definition, the anode switches ends between charge and discharge cycles.

  Vacuum tube anode

In electronic vacuum devices such as a cathode ray tube, the anode is the positively charged electron collector. In a tube, the anode is a charged positive plate that collects the electrons emitted by the cathode through electric attraction. It also accelerates the flow of these electrons.

  Diode anode

In a semiconductor diode, the anode is the P-doped layer which initially supplies holes to the junction. In the junction region, the holes supplied by the anode combine with electrons supplied from the N-doped region, creating a depleted zone. As the P-doped layer supplies holes to the depleted region, negative dopant ions are left behind in the P-doped layer ('P' for positive charge-carrier ions). This creates a base negative charge on the anode. When a positive voltage is applied to anode of the diode from the circuit, more holes are able to be transferred to the depleted region, and this causes the diode to become conductive, allowing current to flow through the circuit. The terms anode and cathode should not be applied to a Zener diode, since it allows flow in either direction, depending on the polarity of the applied potential (i.e. voltage).

  Sacrificial anode

  Sacrificial anodes mounted "on the fly" for corrosion protection of a metal structure

In cathodic protection, a metal anode that is more reactive to the corrosive environment of the system to be protected is electrically linked to the protected system, and partially corrodes or dissolves, which protects the metal of the system it is connected to. As an example, an iron or steel ship's hull may be protected by a zinc sacrificial anode, which will dissolve into the seawater and prevent the hull from being corroded. Sacrificial anodes are particularly needed for systems where a static charge is generated by the action of flowing liquids, such as pipelines and watercraft.

In 1824 to reduce the impact of this destructive electrolytic action on ships hulls, their fastenings and underwater equipment, the Victorian scientist-engineer Sir Humphry Davy, developed the first and still most widely used marine electrolysis protection system. Davy installed sacrificial anodes made from a more electrically reactive (less noble) metal attached to the vessel hull and electrically connected to form a cathodic protection circuit.

A less obvious example of this type of protection is the process of galvanising iron (though the name of the process provides the essential clue). This process coats iron structures (such as fencing) with a coating of zinc metal. As long as the zinc remains intact, the iron is protected from the effects of corrosion. Inevitably, the zinc coating becomes breached, either by cracking or physical damage. Once this occurs, corrosive elements act as an electrolyte and the zinc/iron combination as electrodes. The resultant current ensures that the zinc coating is sacrificed but that the base iron does not corrode. Such a coating can protect an iron structure for a few decades, but once the protecting coating is consumed, the iron rapidly corrodes.

If, conversely, tin is used to coat steel, when a breach of the coating occurs it actually accelerates oxidation of the iron.

At least one anode is found in tank-type water heaters. The anode should be removed and checked after 5 years (sooner if there is a sodium based water softner inline), and replaced if 15 cm (6 inches) or more of bare wire is showing. This will greatly extend the life of the tank.

  Related antonym

The opposite of an anode is a cathode. When the current through the device is reversed, the electrodes switch functions, so anode becomes cathode, while cathode becomes anode, as long as the reversed current is applied, with the exception of diodes where electrode naming is always based on the forward current direction.

  See also


  1. ^ Ross, S, Faraday Consults the Scholars: The Origins of the Terms of Electrochemistry in Notes and Records of the Royal Society of London (1938-1996), Volume 16, Number 2 / 1961, Pages: 187 - 220, [1] consulted 2006-12-22
  2. ^ Faraday, Michael, Experimental Researches in Electricity. Seventh Series, Philosophical Transactions of the Royal Society of London (1776-1886), Volume 124, 01 January 1834, Page 77, [2] consulted 2006-12-27 (in which Faraday introduces the words electrode, anode, cathode, anion, cation, electrolyte, electrolyze)
  3. ^ Faraday, Michael, Experimental Researches in Electricity, Volume 1, 1849, reprint of series 1 to 14, freely accessible Gutenberg.org transcript [3] consulted 2007-01-11

  External links



All translations of Anode

sensagent's content

  • definitions
  • synonyms
  • antonyms
  • encyclopedia

Dictionary and translator for handheld

⇨ New : sensagent is now available on your handheld

   Advertising ▼

sensagent's office

Shortkey or widget. Free.

Windows Shortkey: sensagent. Free.

Vista Widget : sensagent. Free.

Webmaster Solution


A windows (pop-into) of information (full-content of Sensagent) triggered by double-clicking any word on your webpage. Give contextual explanation and translation from your sites !

Try here  or   get the code


With a SensagentBox, visitors to your site can access reliable information on over 5 million pages provided by Sensagent.com. Choose the design that fits your site.

Business solution

Improve your site content

Add new content to your site from Sensagent by XML.

Crawl products or adds

Get XML access to reach the best products.

Index images and define metadata

Get XML access to fix the meaning of your metadata.

Please, email us to describe your idea.


The English word games are:
○   Anagrams
○   Wildcard, crossword
○   Lettris
○   Boggle.


Lettris is a curious tetris-clone game where all the bricks have the same square shape but different content. Each square carries a letter. To make squares disappear and save space for other squares you have to assemble English words (left, right, up, down) from the falling squares.


Boggle gives you 3 minutes to find as many words (3 letters or more) as you can in a grid of 16 letters. You can also try the grid of 16 letters. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame !

English dictionary
Main references

Most English definitions are provided by WordNet .
English thesaurus is mainly derived from The Integral Dictionary (TID).
English Encyclopedia is licensed by Wikipedia (GNU).


The wordgames anagrams, crossword, Lettris and Boggle are provided by Memodata.
The web service Alexandria is granted from Memodata for the Ebay search.
The SensagentBox are offered by sensAgent.


Change the target language to find translations.
Tips: browse the semantic fields (see From ideas to words) in two languages to learn more.

last searches on the dictionary :

4242 online visitors

computed in 0.078s

I would like to report:
section :
a spelling or a grammatical mistake
an offensive content(racist, pornographic, injurious, etc.)
a copyright violation
an error
a missing statement
please precise:



Company informations

My account



   Advertising ▼


Commercial use of this term


Commercial use of this term

47 mm Copper Anode Sphere Ball for plating 503g (20.0 USD)

Commercial use of this term

Lots10~1000Pcs 5mm 4Pin RGB Common Anode/Cathode LED Lamp Emitting Light Diode (52.05 USD)

Commercial use of this term

MVP Discs, SOFT Proton ANODE, NEW, 174g (16.0 USD)

Commercial use of this term

Genuine Suburban 232768 RV Water Heater Aluminum Anode Rod (13.94 USD)

Commercial use of this term

Radiator Corrosion Inhibiting zinc anode (13.95 USD)

Commercial use of this term


Commercial use of this term


Commercial use of this term


Commercial use of this term


Commercial use of this term


Commercial use of this term

Volvo Penta Zinc Anode 873395 (10.0 USD)

Commercial use of this term


Commercial use of this term

OEM Yamaha 115 130 150 175 Trim Torque Tab Skeg Anode 6E5-45371-01-00 SameDay (25.05 USD)

Commercial use of this term


Commercial use of this term

Cast Copper Wing off a Copper Anode, abt. 5-1/2 Lbs. (34.99 USD)

Commercial use of this term

BLOCKSignalling Infra Red Aspect Signals Controller for Common Anode LED's ASP2 (27.0 AUD)

Commercial use of this term

Bravo 3 Aluminum Anode Kit, Mercruiser III I/O 2004' & up. salt / brackish (34.95 USD)

Commercial use of this term