Electrochemical cell

Electrochemical cell refers to a device capable of either generating electrical energy from chemical reactions or facilitating chemical reactions through the introduction of electrical energy. These cells are fundamental to electrochemistry, playing a crucial role in various applications ranging from power generation in batteries to the electroplating of metals.

Types of Electrochemical Cells

Electrochemical cells are broadly categorized into two main types: galvanic cells (or voltaic cells) and electrolytic cells.

Galvanic Cells

Galvanic cells, named after Luigi Galvani, are devices that convert chemical energy into electrical energy through spontaneous redox reactions. These cells consist of two different metals connected by a salt bridge or a porous membrane that allows ions to move between the anode and cathode compartments, thus completing the circuit and allowing the flow of electrons through an external wire. Common examples include the Daniell cell, which is made of copper and zinc electrodes.

Electrolytic Cells

Unlike galvanic cells, electrolytic cells require an external source of electrical energy to induce non-spontaneous chemical reactions. These cells are used in various industrial processes such as the extraction of metals, electroplating, and water electrolysis. In these cells, the anode is positively charged, and the cathode is negatively charged, which is the opposite of their charges in galvanic cells.

Applications

Electrochemical cells have a wide range of applications in everyday life and industrial processes. They are used in the production of electrical batteries, corrosion protection (cathodic protection), electroplating of metals, and the electrolysis of water to produce hydrogen and oxygen. In the medical field, electrochemical cells are used in devices such as pacemakers and biosensors.

Principles of Operation

The operation of electrochemical cells is governed by the principles of redox reactions, where oxidation (loss of electrons) occurs at the anode, and reduction (gain of electrons) occurs at the cathode. The potential difference between the electrodes, known as the cell potential, is a measure of the cell's ability to produce an electric current. The cell potential can be calculated using the Nernst equation, which takes into account the concentrations of the reactants and products.

See Also

• Redox
• Electrode potential
• Nernst equation
• Standard electrode potential