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What is a primary cell? , meaning | type

Hello friends, in today’s article we are going to teach you what is called primary cell and what are the types of it, so if you want to go then read this article completely, then friends let’s start this article.

Meaning of primary cell?

All those cells which cannot be recharged are called primary cells. from chemical energy Electricity There is a means of obtaining energy, when they are immersed, both the electrolyte and the electron are spent, the whole electron or electrolyte These cells become useless on the expenditure of Rs. The electrodes or the electrolyte or both have to be replaced.

In the primary cell, two identical conducting plates, anode and cathode, are immersed in electrolyte, the electrolyte reacts more chemically with one plate and on closing the circuit, electrons move from one plate to another, causing a potential difference between the two electrodes. is established and electric current starts flowing in the circuit. The battery made from these cells is primary battery it is said.

What is primary cell meaning type

Primary cell type

  1. Voltaic Cell
  2. Daniell Cell
  3. Leclanche Cell
  4. Dry Cell
  5. Rechargeable Cell
  6. Mercury Cell
  7. Zinc Chloride Cell
  8. Silver Oxide Cell
  9. Bunsen Cell
  10. Nickel Cadmium Cell
  11. Alkaline Cell
  12. Lithium Cell

Voltaic Cell

It is made of a glass vessel filled with a solution of dilute sulfuric acid and in which copper and zinc rods act as electrodes. In this, the copper rod acts as the positive electrode and the zinc rod as the negative electrode. If the circuit is completed by connecting the electrodes with a wire, a current starts flowing in it because the sulfuric acid ions break down into hydrogen and sulfate ions. H2SO4 → 2H,+ SO4-2

The hydrogen ions start moving in the direction of the current and get deposited in the form of small bubbles on the copper plate. Sulfate ions move towards the zinc plate and react with zinc to form zinc sulphate.

Zn+2 + SO4-2 → ZnSO4 + 2e,

The current inside the cell flows from zinc plate to copper plate and outside copper plate to zinc plate. This is the reason that copper plate acts as anode and zinc plate acts as cathode.

Daniell Cell

In this type of cell copper rod ( + ) anode electrode ) copper sulphate ( CuSO4 ) is immersed in a glass vessel filled with solution. This solution acts as a de-polarizer. A glass vessel with a hole is placed in the middle of this glass vessel, in which amalgamated zinc rod is placed. [ ( – ) कैथोड इलेक्ट्रॉड ] mild H2 SO4 submerged in electrolyte. When a small lamp is placed at the ends of (– ) and ( + ) then a current starts flowing which flows from the copper rod to the zinc rod, then the following chemical reactions take place.

Zn+2 + H2SO4  → ZnSO4 + 2H+
2H+ + CuSO4 → H2SO4  + Cu+2

CuSO4 (Copper Sulphate) acts as a depolarizer in this cell. This cell provides 1.08 V electromotive force. In this, there is a coating of mercury on the zinc rod. When the cell is not to be used, the zinc rod should be taken out of the glass vessel and kept.

Leclanche Cell

Ammonium chloride (NH) in a glass vessel with open mouth as shown in figure ( 8.6 )4 CI) solution is filled in which a zinc rod is installed which acts as a cathode. In the middle of this vessel, a porous glass vessel in which the powder of manganese dioxide and carbon is filled. It acts as a de-polarizer and a carbon rod is placed in the middle which acts as the anode. If a small lamp is connected to the ends of carbon and zinc electrodes, the following chemical reactions take place in the cell. Zn+2 + 2NH4CI → ZnCl2 + 2NH3, + H2

Hydrogen ions move through the porous vessel to the carbon electrode and charge the carbon and split into self-discharged hydrogen atoms. when H2 the atoms of MnO2 They get oxidized when they react with manganese dioxide.

H2+2MnO2 → Mn2O3 +H2O

The viva-force of this cell is 46 volts. These cells are used where continuous current use is not required. Due to being liquid and of glass, it is difficult to carry them everywhere. It is used in telephone, electric bell and torch etc.

Dry Cell

These cells are often used in torches. This primary cell cannot be recharged. Its entire shell is made of zinc. In this, zinc (– ) acts as cathode electrode and carbon rod is attached in the middle which (+ ) acts as anode electrode. A brass round cylindrical cap is mounted on top of a carbon rod. This cell is round cylindrical in shape. It is filled with ammonium chloride paste.

In this, small particles of manganese dioxide and carbon are filled in a fine cloth bag in a zinc vessel. A carbon rod is placed in this pouch, which is separated from the ammonium chloride paste due to the pouch. This pouch is packed or sealed with bitumen paste from above, in which there is a cap of PVC on top in which holes are made to release the gas generated by chemical reaction. The internal resistance of this cell is 0.252 to 0.32. They are widely used in many types of portable devices and torches. it has a certain age

Rechargeable Cell

In these, the cathode (-) electrode is made of zinc and the anode (+) electrode is made of manganese dioxide. The electrolyte is made up of potassium hydroxide. They are used in portable devices, radios, transistors etc.

Mercury Cell

Mercury cells are smaller in size but more energy efficient. Its voltage discharge remains almost the same. It is high temperature tolerant and has a longer life. These cells are prepared from a paste or paste of potassium hydroxide and mercuric oxide.

In these, only these pastes act as electrolytes. (-) The cathode electrode is made of a compound of zinc and mercury, (+) the anode electrode is made of mercuric oxide. They are used in clocks, alarm systems, testing equipment, etc. V.V.B. of these cells 1.35 to 1.45 volts. These cells are button shaped 12.5 mm x 3 mm in thickness. The cell container is made of nickel painted steel to protect against corrosion. The middle electrode in these mercury cells is -ve.

There are two types of mercury cells – one whose voltage is 135 V and the other is 1.4V. Generally, the 1.35 V cell is used in scientific and medical equipment, while the 14 V cell is used for the general consumer.

Zinc Chloride Cell

Zinc chloride cell is a heavy duty cell because the value of the current it receives is high and it can be used for a long time for high current.

The structure of zinc chloride cell is similar to that of dry cell, the difference between these two is only in electrolyte. It does not contain ammonium chloride, but zinc chloride is used as an electrolyte. When water is used while the cell is in action, it dries up completely, so cells are used at low temperatures.

Silver Oxide Cell

These types of cells are very similar to Mercury cells, they provide low load and high voltage. Like mercury cells, silver oxide cells have good energy and flat output voltage characteristics. Its texture and mercury cell

There is no significant difference in texture. In this (+) anode electrode is made of silver oxide and (–) cathode electrode is made of zinc powder.

Bunsen Cell

This Bunsen cell is made of glass vessel. In this, the thin H2 SO4 Occurs in the form of an electrolyte. Tanu H2 SO4 In this, a rod made of zinc plated mercury is kept which acts as the (-) cathode electrode. A glass vessel with holes is placed inside this large vessel and a carbon rod is placed between it, which acts as the (+) anode electrode. Nitric acid HNO in this vessel3 ) is filled.

zinc rod dilute H2 SO4 It reacts with zinc to form sulphate and hydrogen ions. Hydrogen when nitric acid (HNO)3 ) then water and nitrogen dioxide are formed. V of this cell W. B . It is 19V.

Zn + H2 SO4 → ZnSO4 +2H
H+ HNO3 → H2O +NO2

Nickel Cadmium Cell

Its cathode (–) electrode is made of cadmium and anode (+) electrode is made of nickel hydroxide.

( Ni ( OH )4 ) is also used in nickel iron cells, the use of cadmium reduces the internal resistance of the cell. Its use is good for floating type patties. It is used to make batteries for large diesel engines.

Alkaline Cell

In this, the zinc (–) cathode acts as the electrode. The electrode of manganese dioxide is positive. An electrolyte is a solution of potassium hydroxide or an alkaline solution. Alkaline cells are also manufactured in standard sizes like carbon zinc cells. Their value is high and they are capable of supplying high current for a long time. A standard D type 1.5V alkaline cell has a capacity of 3.5 Ah (amper hour) compared to 2Ah (amper hour) from a carbon zinc cell.


  1. high energy density
  2. low internal resistance
  3. Capable of working at low and high temperatures.


  1. high price
  2. Re-charge is not possible.

Lithium Cell

This is also the primary cell. They are available in many sizes and configurations. The voltage of the cell is between 2.5 and 3.6 V depending on the chemicals used with the lithium. They hold higher voltage than other primary cells. It has a lifespan of 10 years and has a high energy-to-weight ratio of 350Wh/kg. These cells operate over a temperature range of 50 to +75 °C. These cells are used in watches, heart related pace makers, torches etc.

Advantages –

  1. high energy density,
  2. low weight,
  3. higher cell voltage,
  4. small size etc.

Disadvantage –

  • higher price.

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