What is Cathode?
A cathode is an electrode that conducts electricity from the battery’s negative terminal to the positive terminal. A cathode is a negatively charged electrode by which electrons enter electrical devices. Cathode attracts cations or positive charges towards itself.
It is a primary cell that helps electrical devices pass or supply current. It helps in the reduction process in chemistry. A cathode is an electrochemical cell. A cathode is a negative electrode that gets electrons from the external circuit and reduces them. While in the case of a galvanic cell, the cathode is positive, and a copper cathode is dipped in copper sulfate (CuSO4) solution.
Copper ions accept electrons from the external cell and reduce them to copper metal which deposits on the cathode. Two types of the cathode are the cold cathode and the hot cathode.
A filament that releases more electrons than provided by thermal radiation and did not electrically heat is called a cold cathode. A filament in which electric current flows is called a hot cathode. Examples of cold cathodes are used in discharge lamps, discharge tubes, and vacuum tubes.
What is Anode?
An anode is an electrode that carries conventional current from the positive terminal of a battery to the negative terminal. It attracts anions or negative charges towards itself. An anode is a positively charged electrode from which electrons leave an electrical device.
An anode is an electrode where an oxidation reaction occurs. In an oxidation reaction, the electron is released to the external circuit. The anode is positive in an electrolytic cell, while in the galvanic cell, it is negative.
Anodes use electrical energy to precede a chemical reaction in an electrolytic cell. While in the galvanic cell, the anode has a negative potential for the solution. The anodes in the galvanic cell are made up of zinc metal dipped in a zinc sulfate solution.
After leaving the election, the zinc metal will oxidize into Zn2+ and provide two electrons to the external circuit.
Difference Between Cathode and Anode
Cathode and electrodes both help conduct electricity in an electrolytic cell. Both of these are used to create electrolytic or electrochemical cells.
- In the cathode, electricity moves out of the electrical circuit. While in the anode, the electricity moves the external circuit.
- The cathode is a negatively charged electrode and is an electron acceptor; because of its negative charge, it can accept positive charges. At the same time, the anode has a positive charge, can accept negative ions, and is an electron donor.
Comparison Between Cathode and Anode
| Parameter | Cathode | Anode |
| Definition | A cathode is an electrode that conducts electricity from the battery’s negative terminal to the positive terminal. | An anode is an electrode that carries conventional current from the positive terminal of a battery to the negative terminal. |
| Charge | Cathode has a negative charge. | Anode has a positive charge on it. |
| Ions | Cathods being negative charge attracts positive ions towards them. It is an electron acceptor. | Anode being a positive charge, attracts negative ions toward them. So, anodes are electron donors. |
| Type of reaction | Reduction reaction occurs at the cathode. | An Oxidation reaction occurs at the anode. |
| Electrolytic cell | In an electrolytic cell cathode has negative ions on it. | In an electrolytic cell, the anode has excess positive ions. |
| Galvanic cell | In a galvanic cell cathode, it has a positive charge and becomes an anode. | In a galvanic cell, the anode has a negative charge on it, and it becomes a cathode. |
References
- Wood, R.W., 1897. A new form of cathode discharge and the production of X-rays, together with some notes on diffraction. Preliminary communication. Physical Review (Series I), 5(1), p.1.
- Zhang, J., Han, J., Yun, Q., Li, Q., Long, Y., Ling, G., Zhang, C. and Yang, Q.H., 2021. What Is the Right Carbon for Practical Anode in Alkali Metal Ion Batteries? Small Science, 1(3), p.2000063.