Though Batteries and cells serve the common purposes of providing the source of power for many electronic devices, yet, they are still different. A cell is the electronic device that stores chemical energy and transforms it into electrical energy to supply power to electronic devices. Now, moving on to what is a battery? A battery is an electronic device that acts just like a cell, the only difference is that it has one or more cells grouped together.
A battery and a cell both can only supply DC voltage and current. They have some chemical reaction stored inside them that gives rise to the electrons on one electrode. Further, the free electrons move from one electrode to another through the electrolytic solution present inside the cell. With this, an electric circuit is established inside the battery cell, giving rise to the electric current that can be used for the functioning of many electronic devices.
Now, you must have developed an idea of what is a battery cell, and how it functions.
A dry cell is a type of electric battery that is mainly used for home appliances and other portable devices. It is the type of electrochemical cell that was developed in 1886 by Carl Gassner, a German scientist. A dry cell is a variety that is currently used in all types of batteries. The dry cell consists of immobilized electrolytes with lower moisture and is mainly in the form of a paste.
Moving on to the battery types, there are two main types of battery based on the nature of the cell. Batteries can be classified into primary and secondary batteries. A primary one is non-rechargeable, and the secondary one is rechargeable.
Given here is a brief on primary cell and secondary cell.
A primary cell or battery is non-rechargeable, and cannot be reused once its electrolyte is all consumed. Once these batteries get discharged, they serve no more purposes and must be disposed. Some common examples of primary cells are the ones used in remotes, wall clocks, watches, and mini electronic gadgets.
There are Two Main Types of Primary Cells/Batteries.
1. Alkaline Batteries
Chemical composition of Zinc with Manganese dioxide forms these batteries. The electrolyte that is used in these types of batteries is potassium hydroxide, and since all the contents are purely alkaline, it is termed as an alkaline battery.
2. Coin Cell Batteries
The coin cell batteries also have alkaline electrolytes, and additionally, they also have the chemicals of lithium and silver oxides. These types of primary batteries are highly efficient in ensuring stable and steady voltage.
A secondary cell or battery is the one that is rechargeable and serves multiple purposes for a longer span. Passing current opposite to the direction of discharge, one can effectively recharge the cell again to its original state. Common examples of secondary cells are the ones used in Cars, UPS, robotics, cordless phones, solar lights, drones, etc.
After learning the secondary cell definition, let us move on to the types of secondary cells.
1. Lead-acid Batteries
These batteries contain lead-acid that is cheaper and used mostly in vehicles. They generally come with a voltage range of 2V to 24V and have a power density of 7 Wh/Kg.
2. Ni-Cd Battery
This type of battery is made of Nickel and Cadmium. It has a lower price, and has a lower discharge rate. These batteries come in multiple sizes and have a minimal voltage of 1.2V. The power density of this battery is 60 Wh/Kg.
3. Ni-MH Battery
These batteries are more preferred than Ni-Cd ones. They have a nominal voltage of 1.25V, are easily available, and have a lower impact on the environment. Their power density is 100Wh/Kg.
4. Li-ion Battery
These batteries are made up of Lithium metal. They are compact and can easily be used in portable devices. These are the best batteries in the secondary categorization, have a normal voltage of 3.7V and a power density of 126 Wh/Kg.
5. Li-Po battery
These batteries are also known as Lithium-ion Polymer batteries as they use polymer gel or electrolyte instead of liquid ones. These batteries are a bit costlier but are highly protected as compared to the Li-ion batteries. They have a power density of 185 Wh/Kg.
Q1: Explain in Brief the Primary and Secondary Cells.
Ans: A primary cell is a non-rechargeable cell that cannot be reused. Once these cells or batteries discharge, they cannot be charged by any amount of voltage. These batteries consume the entire electrolyte and thus complete discharges. Some common usage of these types of batteries is in low-end devices like watches, torches, etc.
On the other hand, a secondary cell is rechargeable. It serves multiple purposes for a longer time and can be recharged by passing some voltage in the opposite direction of its discharging. They are mainly used in high-end devices.
Q2: What are the Names of Electrodes Present in a Cell? Explain Them.
Ans: Electrodes present in any cell or battery are known as cathode and anode.
The anode is the electrode in which the current flows in from any external source. It is a positive electrode as it connects with the positive end of the battery, and electrons get attracted to it.
On the other hand, the cathode is the terminal from which the current flows out. It is the negative electrode as is connected with the negative terminal of the battery. The electrons are emitted out of this electrode.