An electrochemical cell is a device that converts chemical energy into electrical energy or vice versa through redox (reduction-oxidation) reactions. It consists of two electrodes immersed in electrolyte solutions, where one electrode undergoes oxidation (loses electrons) and the other undergoes reduction (gains electrons).
There are two main types of electrochemical cells:
- Galvanic (Voltaic) Cell – produces electricity from spontaneous chemical reactions.
- Example: Daniell cell.
- In this cell, chemical energy is converted into electrical energy.
- Electrolytic Cell – requires electricity to drive a non-spontaneous chemical reaction.
- Example: Electrolysis of water.
- In this cell, electrical energy is converted into chemical energy.
Key components of an electrochemical cell:
- Anode: Electrode where oxidation occurs (electrons are released).
- Cathode: Electrode where reduction occurs (electrons are gained).
- Electrolyte: Conducts ions to complete the circuit.
- External circuit: Allows electrons to flow from anode to cathode.
In simple terms, an electrochemical cell is like a battery or a chemical engine that moves electrons through a circuit using chemical reactions.