Classification of electrochemical cells

Classification of Electrochemical Cells

Electrochemical cells are systems that facilitate the conversion between chemical energy and electrical energy through oxidation-reduction (redox) reactions. These cells are broadly categorized based on how they function and their application in various chemical and industrial processes.

Types of Electrochemical Cells

1. 1. Galvanic (Voltaic) Cells:
   • These cells generate electrical energy from spontaneous redox reactions.
   • Each unit comprises two half-cells, containing a metal electrode immersed in its respective electrolyte solution.
   • Electrons flow from the anode (oxidation) to the cathode (reduction) through an external circuit.
   • Example: Daniell Cell represented as Zn | Zn²⁺ || Cu²⁺ | Cu
2. 2. Electrolytic Cells:
   • In these cells, electrical energy is applied to initiate redox reactions that do not occur spontaneously.
   • An external power source supplies energy to carry out the reaction.
   • The anode is positive and the cathode is negative, opposite to galvanic cells.
   • Example: Electrolysis of molten NaCl to produce Na and Cl₂.

Key Differences Between Galvanic and Electrolytic Cells

Applications

• Galvanic cells are used in batteries (e.g., dry cells, lead-acid batteries).
• Electrolytic cells are used in electroplating, metal extraction, and water splitting.