"... The key components include an anode, the negative pole from
which electrons flow out"
Ah, journalists!
Perhaps the easier convenience to [incorrectly/imprecisely] understand
than to understand actuality for commonly presentable
[scientific/disciplined] truth;- but, then, that need not solely be
bound by what generally holds true for as much any finite sense of
truth, as do leeways among travesties abound for perpetuating the thin
veneer in shallow veils between pragmatism and barbarism. Granted,
though a few scientists, at any given moment, may reach farther,
nonetheless, it is specialism which has greater sway over any
likelihood to account, now-a-days, by what remainder is given when
posed to assess how many digits, indeed, might comprise one hand.
-
An anode is an electrode through which positive electric charge flows
into a polarized electrical device. The flow of charge is an electric
current. A common mnemonic is ACID for Anode Current Into Device; the
key notion is a positive current flows into the device; positive
charges are entering the device through the anode. There is a
complication because a current is often moving electrons, and the
charge on an electron is negative. Positive charge flowing into the
anode is the same as (negative) electrons flowing out of the anode.
Consequently, the direction of electric current is opposite to the
direction of electron flow: electrons flow out of the anode to the
outside circuit.
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. Actually, by the above universal definition of electric
current direction, anode polarity depends on the device type and,
sometimes, even on its operating mode. Consequently, as can be seen
from the following examples, the anode is positive in a device that
consumes power, and the anode is negative in a device that provides
power:
In a discharging battery or galvanic cell (diagram at right), the
anode is the negative terminal because it is where the current flows
into "the device" (i.e. the battery cell). This inward current is
carried externally by electrons moving outwards, negative charge
moving one way constituting positive current flowing the other way.
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, the anode is the positive terminal at the tail of the
arrow symbol (base of the triangle),[clarification needed] 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, the anode 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.
-wiki
