[Chemistry Class Notes] on Battery Pdf for Exam

Batteries are globally used in several electronic devices as a source of power. Well, what do you mean by a battery? And, what is a battery cell? A battery is an electronic device that is required for storing chemical energy and transforming it into the electrical one. Can you imagine your life without a battery? No, right. Let us move on to a more detailed brief on what is a battery, what are their usages, and what are the types of batteries.

Functioning of a Battery

Can you imagine how limited electronic usage will become and how tough our lives will be without those devices on which we are so dependable. And to have them work effectively, batteries are highly important.

The battery is a vital device that helps many electronic devices to work seamlessly. It stores chemical energy and provides electrical energy to many devices. Now, after understanding what a battery is, let us move on to how it functions.

• The storage of energy in the battery and its transformation from one form to another is termed electrochemistry.

• An electrochemical cell supports the functioning of the battery.

• A battery may contain only one or many electrochemical cells.

What is meant by a battery is precisely clear, now, moving on to more details on electrochemical cell. Every electrochemical cell contains two electrodes, that are separated by an electrolyte. Now, moving on to how an electrochemical cell gets the electricity.

The chemical reaction taking place inside the cell generates electrons at one electrode. These electrons then start moving and produces electricity. Inside a battery, a chemical reaction occurs, and the electrons flow from one electrode to another for forming an electric circuit. 

What are the Different Types of Battery?

Batteries are mainly categorized into two types. 

1. Primary Batteries: They are also known as non-rechargeable batteries. These are the batteries that are only beneficial for single-time usage. These batteries cannot get charged and reused. The common examples of primary batteries are Alkaline Batteries and Coin Cell Batteries. These batteries are generally used in watches, clocks, torches, and other low-end electronic devices.

2. Secondary Batteries: They are known as rechargeable batteries. These batteries are the long-term ones, and they are reusable and serve well for multiple purposes. They are a bit costlier than the primary batteries, but they serve the users for a longer span when used carefully with caution and safety. Some common examples of secondary batteries are Lead-acid battery, Lithium-ion battery, etc. These batteries are used mainly in robotics, solar lights, high-end toys, etc.

Some Common Terms Related to the Batteries

When it comes to the batteries, other than Voltage and Current, many terms are related to them. Here is a detailed description of all the related technical terms with the batteries

Power Capacity

It is the energy that gets stored in a battery. It is measured in Watt-hour.

Power Capability

It is the maximum amount of current that the battery is capable of delivering. It is also termed as C-rating.

Nominal Voltage

Since the voltage of the battery stays constant and is not variable, it is known as nominal Voltage, i.e., fixed voltage.

Charging Current

It is the maximum amount of current that can be applied to the battery for charging.

Charging Voltage

It is the maximum amount of voltage that must be applied to the battery to charge it efficiently.

Discharging Current 

It is the maximum amount of current that can be drawn out of the battery and delivered to load. If the current drawn exceeds the stated discharging current, the battery drains up fast, causing it to heat up and it might also explode. 

Shelf Life

Sometimes the batteries stay idle or sealed for a longer span, especially in the shops. The shelf-life is the time for which the battery can stay powered up and usable. It is mainly present for the non-rechargeable batteries, as they are for single usage only. The rechargeable batteries with lower shelf life are still rechargeable after that.

Cut-off Voltage

The voltage for which the battery might get considered as completely discharged is the cut-off voltage. If we try to discharge the battery after that voltage, it might get damaged.

Cycle Life

If a battery is completely charged and then it discharges to 80% of its original capacity, it is said to have complete a cycle. The number of cycles that a battery completes is defined as the cycle life. If the cycle life is more, the battery has a better quality.