Editing Cathode (section)

==Charge flow==
Conventional current flows from cathode to anode outside the cell or device (with electrons moving in the opposite direction), regardless of the cell or device type and operating mode.

Cathode [[Electrical polarity|polarity]] with respect to the [[anode]] can be positive or negative depending on how the device is being operated. Inside a device or a cell, positively charged [[ion|cations]] always move towards the cathode and negatively charged [[ion|anions]] move towards the anode, although cathode polarity depends on the device type, and can even vary according to the operating mode. Whether the cathode is negatively polarized (such as recharging a battery) or positively polarized (such as a battery in use), the cathode will draw electrons into it from outside, as well as attract positively charged [[ion|cations]] from inside.

A battery or [[galvanic cell]] in use has a cathode that is the positive terminal since that is where conventional current flows out of the device. This outward current is carried internally by positive ions moving from the [[electrolyte]] to the positive cathode (chemical energy is responsible for this "uphill" motion). It is continued externally by electrons moving into the battery which constitutes positive current flowing outwards. For example, the [[Daniell cell|Daniell galvanic cell]]'s copper electrode is the positive terminal and the cathode.

A battery that is recharging or an [[electrolytic cell]] performing electrolysis has its cathode as the negative terminal, from which current exits the device and returns to the external generator as charge enters the battery/ cell. For example, reversing the current direction in a [[Daniell cell|Daniell galvanic cell]] converts it into an electrolytic cell<ref name="Reversed Daniell Cell">[http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrolyt.html#c1] {{webarchive|url=https://web.archive.org/web/20110604135153/http://hyperphysics.phy-astr.gsu.edu/HBASE/Chemical/electrolyt.html|date=4 June 2011}}, Daniell cell can be reversed to, technically, produce an electrolytic cell.</ref> where the copper electrode is the positive terminal and also the [[anode]].

In a [[diode]], the cathode is the negative terminal at the pointed end of the arrow symbol, where current flows out of 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 diode]]s or [[solar cell]]s where the current of interest is the reverse current. In [[vacuum tube]]s (including [[cathode-ray tube]]s) it is the negative terminal where electrons enter the device from the external circuit and proceed into the tube's near-vacuum, constituting a positive current flowing out of the device.