What is Electrochemical Cell
An electrochemical cell is a device that uses redox (reduction-oxidation) processes to turn chemical energy into electrical energy or vice versa. It is made up of two half-cells, which are compartments filled with electrodes and electrolytes. In each half-cell, one electrode oxidizes (loses electrons) while the other reduces (gains electrons).
The two half-cells are linked by a conductive channel known as the external circuit, which permits electrons to flow. An electric current is generated as a result of this electron transport. The voltage or potential difference between the two electrodes is measured in volts (V) and is what drives electron migration.
There are two main types of electrochemical cells: galvanic (voltaic) cells and electrolytic cells. In a galvanic cell, also commonly known as a battery, the redox reactions occur spontaneously. Chemical energy is converted into electrical energy, producing a current that can be used to power devices. Examples include alkaline batteries and lead-acid batteries used in cars.
On the other hand, an electrolytic cell uses an external power source to drive a non-spontaneous reaction. This external electrical energy input forces the redox reactions to occur in the desired direction. Electrolytic cells are employed in processes like electroplating, metal refining, and water splitting for hydrogen, electroplating, electrolysis of water, and electrolytic production of chemicals. They allow for the deposition of metals onto a surface, purification of metals, and can even facilitate the decomposition of water into hydrogen and oxygen gases.
Electrochemical cells are essential in a variety of applications. They find application in portable electronic gadgets, transportation, renewable energy systems, and industrial operations. Understanding the concepts and functioning of electrochemical cells is critical for progressing in domains like energy storage, electrochemistry, and materials research.
In conclusion, electrolytic cells employ external electrical energy to drive non-spontaneous reactions, whereas galvanic cells generate electrical energy through spontaneous reactions. Both forms of electrochemical cells are important in a variety of applications, ranging from industrial operations to portable power sources.
Advantages and disadvantages of Electrolytic and Galvanic cell
Advantages of Electrolytic Cells:
Wide range of applications:
Electrolytic cells are used in a variety of industries for operations such as electroplating, electrolysis, and electrolytic refining. Electrochemical synthesis and electrochemical sensors are also applications.
Accurate control:
Electrolytic cells provide accurate control of material deposition or dissolution, making them perfect for sectors where precision is critical.
Enormous quantities:
Because electrolytic cells can create enormous amounts of the desired product, they are suitable for industrial-scale manufacturing.
Purification:
Electrolytic cells can be used to purify metals by selectively removing contaminants using electrolysis.
Disadvantages of Electrolytic Cells:
High energy consumption:
High energy usage:
The operation of electrolytic cells is powered by an external power source. Because of the significant energy consumption that results, they are less energy-efficient than other processes.
Required Cost:
Specialized tools and materials are needed to set up and maintain electrolytic cells, which may be expensive.
Environmental issues:
The electrolytic process occasionally produces waste byproducts or releases hazardous substances that must be handled carefully and disposed of.
Limited uses:
Electrolytic cells have a limited range of uses and may not be appropriate for all chemical reactions. They might not work well for making non-metallic elements or extremely reactive compounds, for instance.
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| Electrolytic Cell |
Advantages of Galvanic Cells:
Portable and self-contained:
Galvanic cells, commonly known as batteries, are portable and can provide a source of electricity
without the need for an external power supply or continuous connection.
Longer shelf life:
Batteries have a relatively long shelf life as they can store energy for an extended period without significant discharge.
Easy to use:
Galvanic cells are ready to use and do not require any special installation or setup. They can be easily replaced when depleted.
Versatile:
Galvanic cells come in different sizes and configurations, making them suitable for a wide range of applications, from powering small electronic devices to large-scale applications like emergency power backup.
Disadvantages of Galvanic Cells:
Limited lifespan:
Batteries have a limited lifespan and will eventually become depleted and need to be replaced or recharged.
Environmental impact:
Improper disposal of batteries can lead to environmental pollution due to the presence of toxic metals like mercury and lead.
Expenses:
Batteries can be expensive, especially high-capacity ones or rechargeable batteries that require an additional charging system.
Limited power output:
Galvanic cells have limited power output compared to other power sources, making them unsuitable for high-power applications. Additionally, their voltage gradually decreases as they discharge, resulting in lower efficiency over time.
Chemical reactions products:
The chemical reactions within galvanic cells can generate heat or produce harmful gases, which can be hazardous if not handled properly.
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| Galvanic Cell |
Major Differences between Electrolytic cell and Galvanic cell
The following are the main variations:
Energy Transformation:
Galvanic cells convert chemical energy into electrical energy as a result of internal chemical processes, which enable the passage of electrons from the anode to the cathode. A spontaneous electric current results from this. However, in an electrolytic cell, a non-spontaneous chemical reaction is powered by electrical energy from an external power source. This indicates that the direction of electron flow has switched from cathode to anode.
Purpose:
Galvanic cells are typically used to produce and provide electricity, such in batteries. They are frequently employed in gadgets that need a portable and practical energy source. Conversely, electrolytic cells are employed in a variety of electrochemical procedures that call for particular chemical processes to take place. These procedures may involve chemical compound synthesis, electroplating, and electrolysis.
Construction or Structure:
Galvanic cells are made up of two distinct half-cells, each having a unique metal electrode submerged in an electrolyte solution. The half-cells are linked by an external circuit, which permits electron flow. The two electrodes of electrolytic cells, on the other hand, are normally submerged in an electrolyte solution. However, unlike galvanic cells, the two electrodes in an electrolytic cell are often made of the same material.
Spontaneity of Reactions:
The chemical processes in a galvanic cell take place spontaneously or without the need for external energy. The reactions go in a direction that causes an energy release. The processes in an electrolytic cell are not spontaneous; instead, they need an external electrical energy source to propel them in the desired direction.
Sign of the cell potential:
The positive cell potential in a galvanic cell signifies that the reaction is spontaneous and is releasing energy. In contrast, a negative cell potential in an electrolytic cell denotes an energy-input-required, non-spontaneous response.
Overall, the main difference between electrolytic cells and galvanic cells lies in their purpose, energy flow direction, and how the reactions are driven.
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