Electrochemical Power Sources

Electrochemical power sources are devices that convert chemical energy into electrical energy through electrochemical reactions. These power sources play a crucial role in various applications, including portable electronics, electric vehicles, and renewable energy storage. There are several types of electrochemical power sources, each with its own set of characteristics and applications. Here are some of the most common ones:

Faraday’s Laws of Electrolysis

These laws describe the quantitative relationship between the amount of material liberated or deposited during electrolysis and the amount of electric charge passed through the electrolyte.

Polarization or Back e.m.f.:

Polarization occurs in electrolytic cells due to the resistance offered by the electrodes and the electrolyte to the flow of current. Back electromotive force (e.m.f.) opposes the applied voltage during electrolysis.

Value of Back e.m.f.:

The value of back e.m.f. depends on the characteristics of the specific electrolytic cell and the materials involved.

Primary and Secondary Batteries:

Primary batteries are non-rechargeable, while secondary batteries are rechargeable.

Classification of Secondary Batteries based on their Use:

Batteries can be classified based on their application, such as automotive, industrial, or consumer electronics.

Classification of Lead Storage Batteries:

Lead-acid batteries are classified based on their construction and application.

Parts of a Lead-acid Battery:

Parts include positive and negative plates, separators, electrolyte, and the battery case.

Active Materials of Lead-acid Cells:

The active materials are lead dioxide (positive plate), sponge lead (negative plate), and sulfuric acid (electrolyte).

Chemical Changes:

During discharge, lead sulfate forms on both plates. During charging, lead sulfate converts back to lead dioxide and sponge lead.

Formation of Plates of Lead-acid Cells:

The plates are formed through specific processes like the Plante process and the Faure process.

Plante Process:

A method for manufacturing lead-acid battery plates.

Structure of Plante Plates:

The plates have a dense structure and are less porous.

Faure Process:

Another method for manufacturing lead-acid battery plates.

Positive Pasted Plates; Negative Pasted Plates:

Plates with active material pastes applied.

Structure of Faure Plates:

These plates have a more porous structure compared to Plante plates.

Comparison: Plante and Faure Plates:

Differences in structure and manufacturing processes.

Internal Resistance and Capacity of a Cell:

Internal resistance affects the efficiency of the cell, and capacity refers to the amount of charge a battery can store.

Two Efficiencies of the Cell:

Coulombic efficiency and voltage efficiency.

Electrical Characteristics of the Lead-acid Cell:

Including voltage profiles during charging and discharging.

Battery Ratings:

Specifications indicating the performance and capacity of a battery.

Indications of a Fully-Charged Cell:

Parameters like specific gravity and voltage.

Application of Lead-acid Batteries:

Widely used in automotive and uninterruptible power supply (UPS) systems.

Voltage Regulators:

Devices that maintain a steady voltage output.

End-cell Control System:

Monitoring and controlling individual cells in a battery.

Number of End-cells:

The final cells in a battery pack.

Charging Systems:

Methods like constant-current, constant-voltage, and trickle charging.

Sulphation-Causes and Cure:

Formation of lead sulfate and methods to mitigate it.

Maintenance of Lead-acid Cells:

Practices to prolong battery life.

Mains Operated Battery Chargers:

Chargers powered by the electrical grid.

Car Battery Charger:

Chargers designed for automotive batteries.

Automobile Battery Charger:

Chargers specifically for vehicle batteries.

Static Uninterruptable Power Systems:

Backup power systems that provide continuous power during outages.

Alkaline Batteries:

Batteries using an alkaline electrolyte.

Nickel-Iron or Edison Batteries:

Rechargeable batteries with nickel and iron electrodes.

Comparison: Lead-acid and Edson Cells:

Differences between these battery types.

Silver-Zinc Batteries:

Batteries utilizing silver and zinc electrodes.

High-Temperature Batteries:

Batteries designed for use in elevated temperatures.

Secondary Hybrid Cells:

Batteries combining characteristics of different types.

Fuel Cells:

Devices converting chemical energy directly into electrical energy.

Hydrogen-Oxygen Fuel Cells:

Fuel cells using hydrogen and oxygen as reactants.

Batteries for Aircraft:

Specific batteries designed for aviation applications.

Batteries for Submarines:

Batteries used in submarines for underwater propulsion.