katoda
Katoda is the term for the electrode at which reduction occurs in an electrochemical cell. In galvanic (voltaic) cells the cathode is the positive terminal, while in electrolytic cells it is negative, because an external source forces electrons into the electrode. Regardless of polarity, the cathode is the site where cations in the electrolyte gain electrons and are reduced.
In galvanic applications such as the Daniell cell, electrons flow from the anode to the cathode through
In electronics the term is also used for the electrode that emits electrons in devices such as
Common cathode materials include metals and metal oxides; thermionic cathodes often use tungsten or oxide-coated tungsten.