Cathode

A cathode is the <a href="/facts/Electrode/251PaKX8">electrode</a> from which a <a href="/facts/Conventional_current/Dc1xdnUX">conventional current</a> leaves a polarized electrical device such as a <a href="/facts/Lead-acid_battery/84b8hALA">lead-acid battery</a>. This definition can be recalled by using the <a href="/facts/Mnemonic/6HfDn0ks">mnemonic</a> CCD for Cathode Current Departs. A conventional current describes the direction in which positive charges move. Electrons have a negative electrical charge, so the movement of electrons is opposite to that of the <a href="/facts/Conventional_current/Dc1xdnUX">conventional current</a> flow. Consequently, the mnemonic cathode current departs also means that electrons flow into the device's cathode from the external circuit. For example, the end of a household battery marked with a + (plus) is the cathode.
The electrode through which conventional current flows the other way, into the device, is termed an <a href="/facts/Anode/TjYt95zG">anode</a>.

Cathode open-in-new

Cathode