What Are Primary and Secondary Battery Types with Examples and Uses
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.
Functioning of a Battery
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.
Dry Cell
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.
Different Types of Batteries
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.
What is the Primary Battery?
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.
What is a Secondary Cell?
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.
FAQs on Battery Types and Their Classification in Chemistry
1. What are the main types of batteries in chemistry?
The main types of batteries are primary batteries (non-rechargeable) and secondary batteries (rechargeable). In electrochemistry, they are classified based on whether the redox reaction is reversible.
- Primary batteries: Irreversible chemical reactions (e.g., alkaline battery).
- Secondary batteries: Reversible redox reactions, can be recharged (e.g., lead–acid, lithium-ion).
- Both types convert chemical energy into electrical energy through oxidation–reduction reactions.
2. What is the difference between primary and secondary batteries?
The key difference is that primary batteries cannot be recharged, while secondary batteries can be recharged because their reactions are reversible.
- Primary battery: Chemical reaction proceeds in one direction only (e.g., Zn–MnO2 alkaline cell).
- Secondary battery: External current reverses the reaction during charging (e.g., lead–acid battery).
- Secondary cells are used in cars, phones, and laptops due to rechargeability.
3. How does a lithium-ion battery work chemically?
A lithium-ion battery works by reversible movement of Li+ ions between electrodes during charge and discharge. During discharge, a simplified overall reaction is:
LiC6(s) + CoO2(s) → C6(s) + LiCoO2(s)
- Oxidation at anode: Lithium leaves graphite as Li+.
- Reduction at cathode: Li+ inserts into cobalt oxide.
- Electrons flow through the external circuit, producing current.
4. What is the chemical reaction in a lead–acid battery?
The overall discharge reaction in a lead–acid battery is:
Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l).
- Anode (oxidation): Pb → PbSO4
- Cathode (reduction): PbO2 → PbSO4
- Electrolyte: Sulfuric acid (H2SO4)
5. What is an alkaline battery and how does it work?
An alkaline battery is a primary battery that uses zinc and manganese dioxide in an alkaline electrolyte (KOH). The overall reaction is:
Zn(s) + 2MnO2(s) + 2H2O(l) → Zn(OH)2(s) + 2MnOOH(s).
- Anode: Zinc is oxidized.
- Cathode: MnO2 is reduced.
- Electrolyte: Potassium hydroxide (KOH).
6. What are the different types of rechargeable batteries?
The main types of rechargeable batteries are lead–acid, nickel–cadmium (Ni–Cd), nickel–metal hydride (Ni–MH), and lithium-ion.
- Lead–acid: Used in cars and backup power systems.
- Ni–Cd: Durable but contains toxic cadmium.
- Ni–MH: Higher capacity than Ni–Cd, used in AA rechargeable cells.
- Lithium-ion: High energy density, used in electronics and EVs.
7. What is the chemical reaction in a nickel–cadmium battery?
The overall discharge reaction in a nickel–cadmium (Ni–Cd) battery is:
Cd(s) + 2NiO(OH)(s) + 2H2O(l) → Cd(OH)2(s) + 2Ni(OH)2(s).
- Anode: Cadmium is oxidized to Cd(OH)2.
- Cathode: NiO(OH) is reduced to Ni(OH)2.
- Electrolyte: Potassium hydroxide (KOH).
8. What is a dry cell battery?
A dry cell is a primary battery that uses a paste electrolyte instead of a liquid solution. The classic zinc–carbon cell involves the simplified reaction:
Zn(s) + 2MnO2(s) + 2NH4Cl(aq) → ZnCl2(aq) + Mn2O3(s) + 2NH3(aq) + H2O(l).
- Anode: Zinc container.
- Cathode: Carbon rod with MnO2.
- Electrolyte: Ammonium chloride paste.
9. What is the difference between lithium-ion and lithium metal batteries?
The main difference is that lithium-ion batteries are rechargeable, while lithium metal batteries are primary (non-rechargeable).
- Lithium-ion: Lithium exists as Li+ ions moving between host materials (e.g., graphite and LiCoO2).
- Lithium metal: Uses metallic lithium as the anode.
- Lithium-ion batteries are safer and widely used in electronics and electric vehicles.
10. How do electrochemical cells generate electricity in batteries?
Electrochemical cells generate electricity through spontaneous redox reactions that transfer electrons from the anode to the cathode. For example, in a Daniell cell:
Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)
- Anode: Oxidation (Zn → Zn2+ + 2e-).
- Cathode: Reduction (Cu2+ + 2e- → Cu).
- Electron flow through the external circuit produces electric current.
