Part of the Computing fundamentals glossary:

A cathode is the metallic electrode through which current flows out in a polarized electrical device.

Conversely, an anode is the electrode in a polarized electrical device through which current flows in from an outside circuit. Cathodes get their name from cations (positively charged ions) and anodes from anions (negatively charged ions).

In a device that uses electricity, the cathode is the negatively charged electrode. Such devices include diodes, vacuum tubes, cathode ray tubes, oscilloscopes, electrolytic cells in hydrogen production and secondary battery cells in rechargeable batteries. 

However, in a device that produces power the cathode is the positive terminal, due to the flow of electrons being reversed. Such devices include galvanic cells and primary cell non-rechargeable batteries, as well as secondary battery cells (rechargeable) when the energy within the battery is being consumed.

In many applications, since the cathode gains electrons to produce current, it gradually gains mass from the cations it attracts.

See a video demonstration:

This was last updated in June 2014
Contributor(s): Matthew Haughn
Posted by: Margaret Rouse

Related Terms

Definitions

  • flash storage

    - Flash storage, based on flash memory, is used for data repositories, storage systems and consumer devices, such as USB drives, smartphones and solid-state drives. Flash-based storage is faster than... (WhatIs.com)

  • statistical mean, median, mode and range

    - Calculating the mean, median, mode and range of a set of numbers allows you to track changes over time and set acceptable ranges and variance. Here's how to find your data's mean, median, mode or r... (SearchDataCenter.com)

  • Schrodinger's cat

    - Schrodinger's cat explained: This definition describes Schrodinger's famous thought experiment and its place in quantum theory. (WhatIs.com)

Glossaries

  • Computing fundamentals

    - Terms related to computer fundamentals, including computer hardware definitions and words and phrases about software, operating systems, peripherals and troubleshooting.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About cathodePowered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.