Positive-positive-oxygen, negative-negative-return
The anode connected to the positive pole of the power supply has an oxidation reaction, and the cathode connected to the negative pole of the power supply has a reduction reaction.
Compared with the primary battery, the anode is oxidized and reduced.
Primary battery: divided into positive electrode and negative electrode, anion to negative electrode, cation to positive electrode and negative electrode to positive electrode. The negative electrode with external power supply is connected to the cathode and the positive electrode is connected to the anode.
Understanding: The negative electrode undergoes an oxidation reaction, losing electrons, becoming cations, and anions go to the negative electrode, attracting positive and negative ions.
basic concept
(1) The process of passing current through electrolyte solution or molten electrolyte and causing reduction-oxidation reaction at anode and cathode is called electrolysis.
(2) The device that converts electric energy into chemical energy is called electrolytic cell or electrolytic cell.
(3) When the ions reach the electrode, they lose or gain electrons, and a redox reaction occurs.
Cathode: the electrode connected to the negative pole of the power supply. (electrons are reduced)
Anode: the electrode connected to the positive pole of the power supply. (Loss of electrons leads to oxidation reaction)