Types Of Battery - Primary cell & Secondary Cell

Types Of Battery - Primary cell & Secondary cell

Edited By Shivani Poonia | Updated on Jul 02, 2025 06:12 PM IST

Italian scientist Alessandro Volta in 1800 formed the battery and that's called the Voltas invention and also known by the name of voltaic Pile. The invention of the battery was a great discovery at that time. Before the battery, there were no electricity experiments because it was unsafe to experiment directly from the electricity.

This Story also Contains

Types Of Batteries
Secondary cell
Some Solved Examples
Summary

Types Of Battery - Primary cell & Secondary cell

Types Of Batteries

Batteries can be categorized based on their chemistry, usage, and whether they are rechargeable or non-rechargeable.

Non-rechargeable batteries are called primary cell

Rechargeable batteries are called secondary cell

Primary Cells

In such cells, redox reaction occurs only once so cells can not be recharged again. The cell becomes dead after some time as electrode reactions cannot be reversed. For example, dry cells and mercury cells.

Dry Cell
- It is a compact form of the Lechlanche cell.
- It has an anode of Zn-container and a cathode of graphite rod surrounded by MnO₂ + carbon.
- Here a paste of NH₄Cl and ZnCl₂ is filled in between the electrodes.
  
  Cell Reactions
  At anode:
  Zn(s)→Zn+2(aq)+2e−
  At cathode:2MnO2( s)+2NH44(aq)+2e→Mn2O3( s)+2NH3( g)+H2O
- Zn⁺² combines with NH₃ to form diammine Zn(II) cation.
- A dry cell has a short life as NH₄Cl (acidic) corrodes the Zn-container even if the cell is not in use.
- The cell potential is 1.25 to 1.5 volt
Mercury Cell
- In commonly used mercury cells the reducing agent is zinc and the oxidizing agent is mercury(II) oxide.
  
  Cell Reactions
  At anode:
  Zn(Hg)+2OH→ZnO(s)+H2U+2em
  
  At cathode:
  HgO+H2O+2e−→Hg(l)+2OH
- The overall reaction is:Zn(Hg)+HgO(s)→ZnO(s)+Hg(l)
- The cell potential is approximately 1.35 V and remains constant throughout its life as the overall reaction does not involve any ion, whose concentration can change during its lifetime. It is used in hearing aids, watches, etc.

Secondary cell

A secondary cell, also known as a rechargeable battery, is a type of battery that can be recharged and used multiple times. Unlike primary cells, which are designed for single-use and must be disposed of once depleted, secondary cells can be restored to their full charge by applying an external electrical current.

Rechargeability
- Secondary cells can be recharged and used again after the initial discharge. This is achieved through a process where electrical energy is converted into chemical energy during charging.

Chemistry
- Various chemistries are used in secondary cells, including:
- Lead-Acid: Uses lead and lead dioxide electrodes with a sulfuric acid electrolyte.
- Nickel-Cadmium (NiCd): Uses nickel and cadmium electrodes with a potassium hydroxide electrolyte.

Applications
- Secondary cells are widely used in various applications, including:
- Consumer Electronics: Smartphones, laptops, tablets, and cameras.
- Electric Vehicles: Batteries for electric cars, bicycles, and scooters.
-*Power Tools: Rechargeable drills, saws, and other tools.
- Energy Storage Systems: Home energy storage and backup power solutions.

Advantages
- Cost-Efficient: Over time, secondary cells can be more economical than primary cells because they can be reused multiple times.
- Environmental Impact: Rechargeable batteries reduce waste since they do not need to be disposed of after a single use.
- Performance: Modern secondary cells often provide higher energy density and better performance compared to primary cells.

Disadvantages
-Initial Cost: Rechargeable batteries can be more expensive upfront compared to disposable ones.
- Maintenance: They may require specific charging protocols and can degrade over time, reducing their effective lifespan.

Some Solved Examples

Example.1

1. Choose the correct option :

a) Mercury batteries using a mercury oxide cathode have a flat discharge curve

b) Mercury batteries are used in voltage reference in electric instruments and in photographic light meters

c) Silver oxide batteries are used as an alternative to mercury batteries

1)a,b

2)b

3) (correct)a,b,c

4)a,c

Solution

Mercury batteries using mercury oxide cathode have a flat discharge curve and provide a constant voltage of 1.35 v for 95% of their lifetime. The rest is also correct.

Hence, the answer is the option (3).

Example.2

2 . Select the correct option in the context of dry cell

a) it is also called Lechlance cell

b) It can also be called Daniel cell

c) Electrolyte used is a moist paste of PbSO4 and PbSO4

1)a,c

2) (correct)c

3)a,b

4)b,c

Solution

As we have learned,

Batteries - Primary Cells
In such cells, redox reaction occurs only once so cells can not be recharged again. The cell dies after some time as electrode reactions cannot be reversed—for example, dry cells and mercury cells.

Dry Cell
- It is a compact form of the Leclanche cell.
- It has an anode of Zn-container and a cathode of graphite rod surrounded by MnO₂ + carbon.
- Here a paste of NH₄Cl and ZnCl₂ is filled in between the electrodes.
  Cell Reactions
  At anode:
  Zn(s)→Zn+2(aq)+2e−
- At cathode:2MnO2( s)+2NH4+(aq)+2e−→Mn2O3( s)+2NH3( g)+H2O
- Zn⁺² combines with NH₃ to form diammine Zn(II) cation.
- A dry cell has a short life as NH₄Cl (acidic) corrodes the Zn-container even if the cell is not in use.
- The cell potential is 1.25 to 1.5 volt
Lechlance and Daniel cells are different from dry cell

Hence, the answer is the option (2).

Example.3

3. A depolarizer used in dry cells is:

1)Ammonium chloride

2) (correct)Manganese dioxide

3)Potassium oxide

4)Sodium phosphate

Solution

As we have learned,

Dry Cell
- It is a compact form of the Leclanche cell.
- It has an anode of Zn-container and a cathode of graphite rod surrounded by MnO₂ + carbon.
- Here a paste of NH₄Cl and ZnCl₂ is filled in between the electrodes.
  Cell Reactions
  At anode:
  Zn(s)→Zn+2(aq)+2e−
- At cathode:2MnO2( s)+2NH4+(aq)+2e−→Mn2O3( s)+2NH3( g)+H2O
- Zn⁺² combines with NH₃ to form diammine Zn(II) cation.
- A dry cell has a short life as NH₄Cl (acidic) corrodes the Zn-container even if the cell is not in use.
- The cell potential is 1.25 to 1.5 volts

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MnO₂ acts as the depolarizer and presents the buildup of hydrogen gas molecules.

Hence, the answer is the option (2).

Example.4

4. Choose the incorrect option in the context of mercury cell :

a) AqO+KOH is used as an electrolyte

b) Zn is used as an electrolyte.

c) ZnO+KOH is used as an electrolyte

1)a,b.c

2) (correct)a,b

3)b,c

4)b

Solution

Electrolyte moist paste of KOH.

Cathode reaction IgO(s)+H2O(l)+2e−→Hg(1)+2OH−

Anode reaction Zn(Hg)+2OH−→ZnO(s)+H2O+2e−

ZnO+KOH◻ in the moist form is used as an electrolyte and zinc is used as an anode.

Hence, the answer is the option (2).

Example.5

5. Compound A used as a strong oxidizing agent is amphoteric. It is part of lead storage batteries. Compound A is:

1)PbO

2)Pb₃O₂

3) (correct)PbO₂

4)PbSO4

Solution

PbO₂ is an amphoteric and strong oxidizing agent and also a component of lead storage batteries in the cathode

Hence, the answer is the option (3).

Summary

Batteries are important as they provide a source of energy this feature makes them very important as they are used in mobiles and many more things. Dry cells are very small and easy to carry with them and due to their small size, they are very portable so they can be used in small devices. Mercury cells provide a consistent voltage output over a wide range of temperatures and has long shell life.

Frequently Asked Questions (FAQs)

1. What is the main difference between primary and secondary cells?

The key difference is rechargeability. Primary cells are single-use batteries that cannot be recharged once depleted. Secondary cells, also known as rechargeable batteries, can be recharged and reused multiple times.

2. How do secondary cells allow for recharging?

Secondary cells use reversible chemical reactions. When discharged, the chemical reactions can be reversed by applying an external electric current, restoring the original chemical composition and allowing the battery to be used again.

3. Can you name some widely used secondary cells?

Popular secondary cells include lithium-ion batteries (used in smartphones and laptops), nickel-metal hydride (NiMH) batteries, and lead-acid batteries (used in cars).

4. How does the energy density of primary cells compare to secondary cells?

Generally, primary cells have a higher energy density than secondary cells. This means they can store more energy per unit volume or weight, which is why they're often used in devices that require long-lasting power but are not frequently used.

5. Why can't primary cells be recharged?

Primary cells cannot be recharged because the chemical reactions that produce electricity are not easily reversible. Once the active materials are consumed, they cannot be restored through the application of an external electric current.

6. What are some common examples of primary cells?

Common primary cells include alkaline batteries (e.g., AA, AAA), zinc-carbon batteries, and lithium batteries used in watches and some medical devices.

7. Why are primary cells still used if secondary cells are rechargeable?

Primary cells are still used because they have advantages in certain applications. They have a longer shelf life, higher energy density, and are often cheaper for single-use purposes. They're ideal for low-drain devices or emergency equipment that isn't used frequently.

8. How does the self-discharge rate differ between primary and secondary cells?

Primary cells typically have a lower self-discharge rate than secondary cells. This means they can retain their charge for longer periods when not in use, making them suitable for devices that are used infrequently or need to be ready for emergencies.

9. What is the role of the electrolyte in both primary and secondary cells?

The electrolyte facilitates the movement of ions between the electrodes in both types of cells. It's a crucial component that enables the flow of electric current by allowing ions to move freely within the cell.

10. How does the internal resistance change over time in primary vs. secondary cells?

In primary cells, internal resistance generally increases over time as the active materials are consumed, leading to decreased performance. In secondary cells, internal resistance can increase with repeated charge-discharge cycles, but proper maintenance can slow this process.

11. How do environmental factors affect the performance of primary and secondary cells differently?

Both types are affected by temperature, but secondary cells are generally more sensitive. Extreme temperatures can reduce the capacity and lifespan of secondary cells more significantly. Primary cells are often more robust in varying environmental conditions.

12. How does the concept of "state of charge" (SOC) apply differently to primary and secondary cells?

State of charge refers to the level of charge in a battery compared to its capacity. It's more commonly used with secondary cells, where knowing the SOC is crucial for proper charging and usage. For primary cells, SOC is less relevant as they are used until depletion. Some primary cells have built-in charge indicators, but these are less precise than SOC measurements in secondary cells.

13. How do primary and secondary cells compare in terms of their internal pressure during operation?

Internal pressure can build up in both primary and secondary cells during operation, but it's generally more of a concern in secondary cells, especially during charging. Many secondary cells have safety vents to release excess pressure. In primary cells, pressure build-up is usually less significant but can occur near the end of their life, potentially leading to leakage.

14. How do the disposal and recycling processes differ for primary and secondary cells?

Both primary and secondary cells require proper disposal due to their potentially harmful materials. However, secondary cells, especially lithium-ion batteries, often have more established recycling processes due to their higher value and environmental impact. Primary cells are more likely to end up in landfills, though efforts are increasing to recycle them as well.

15. What is the significance of the "C-rate" in battery specifications, and how does it apply differently to primary and secondary cells?

The C-rate is a measure of

16. What happens inside a secondary cell during charging?

During charging, an external electric current is applied to the secondary cell. This current drives the chemical reactions in reverse, converting the discharge products back into the original active materials, essentially "storing" electrical energy as chemical energy.

17. What is the "memory effect" in batteries, and which type of cell does it affect?

The "memory effect" is a phenomenon where certain rechargeable batteries appear to "remember" smaller capacities if they are repeatedly recharged after only partial discharge. It primarily affects nickel-cadmium (NiCd) secondary cells and, to a lesser extent, nickel-metal hydride (NiMH) batteries.

18. Why are lithium-ion batteries considered superior to other types of secondary cells?

Lithium-ion batteries have several advantages: high energy density, low self-discharge rate, no memory effect, and a higher number of charge-discharge cycles. These properties make them ideal for portable electronic devices and electric vehicles.

19. What safety concerns are associated with primary and secondary cells?

Both types can pose safety risks if damaged or improperly used. Primary cells may leak corrosive materials if left too long after depletion. Secondary cells, especially lithium-ion, can overheat or catch fire if damaged or overcharged. Proper handling and disposal are crucial for both types.

20. How does the cost per use differ between primary and secondary cells?

While primary cells are often cheaper upfront, secondary cells can be more cost-effective in the long run for frequently used devices. The initial higher cost of secondary cells is offset by their ability to be recharged many times.

21. What is meant by the "C-rate" in battery specifications, and how does it apply to primary and secondary cells?

The C-rate is a measure of the rate at which a battery is charged or discharged relative to its capacity. It's more commonly used with secondary cells to describe charge and discharge rates. Primary cells are typically not described using C-rates as they are not designed for recharging.

22. How do primary and secondary cells differ in terms of their impact on the environment?

Primary cells generally have a larger environmental impact as they are discarded after a single use, contributing more to waste. Secondary cells, while containing potentially harmful materials, can be used many times before disposal, reducing overall waste. However, proper recycling is important for both types.

23. What is a fuel cell, and how does it differ from primary and secondary cells?

A fuel cell is an electrochemical device that converts chemical energy from fuel into electricity. Unlike primary and secondary cells, fuel cells can continuously produce electricity as long as fuel is supplied. They don't store energy like batteries but generate it through a constant chemical reaction.

24. How do the discharge curves differ between primary and secondary cells?

Primary cells typically have a more stable voltage output during discharge, with a relatively flat discharge curve until near depletion. Secondary cells often have a more sloping discharge curve, with voltage gradually decreasing as the cell discharges.

25. What is the "open-circuit voltage" and how does it relate to battery type?

The open-circuit voltage is the voltage across the terminals of a battery when no load is connected. In primary cells, this voltage remains relatively constant until near depletion. In secondary cells, it can vary more significantly with the state of charge.

26. How does the concept of "capacity fading" apply to primary and secondary cells?

Capacity fading refers to the gradual loss of a battery's ability to hold charge. It's more relevant to secondary cells, where repeated charge-discharge cycles can lead to a reduction in capacity over time. Primary cells don't experience capacity fading in the same way, as they're not designed for multiple uses.

27. What is a "button cell" and why is it typically a primary cell?

A button cell is a small, disc-shaped battery commonly used in watches, hearing aids, and small electronic devices. They are typically primary cells because their small size makes it challenging to incorporate recharging mechanisms, and they're often used in low-drain devices where long shelf life is more important than rechargeability.

28. How do primary and secondary cells behave differently at low temperatures?

Both types of cells perform poorly at low temperatures, but primary cells generally fare better. Low temperatures slow down chemical reactions, reducing power output. Secondary cells, especially lithium-ion, can be more severely affected, with significant capacity loss and potential for damage if charged at very low temperatures.

29. What is the "shelf life" of a battery, and how does it differ between primary and secondary cells?

Shelf life refers to how long a battery can be stored before its performance significantly degrades. Primary cells typically have a longer shelf life, often several years, due to their lower self-discharge rates. Secondary cells generally have shorter shelf lives, especially if stored in a partially charged state.

30. How does the internal structure of primary and secondary cells differ?

The internal structure of primary cells is typically simpler, designed for one-time use. Secondary cells often have more complex structures to facilitate the reversible chemical reactions needed for recharging. This can include special separators, electrolyte formulations, and electrode designs that allow for repeated charge-discharge cycles.

31. What is a "deep cycle" battery, and is it a primary or secondary cell?

A deep cycle battery is a type of secondary cell designed to be regularly deeply discharged using most of its capacity. It's commonly used in applications like solar energy storage or electric vehicles. Unlike standard car batteries (also secondary cells), deep cycle batteries can withstand repeated deep discharges without significant damage.

32. How do primary and secondary cells compare in terms of power density?

Power density refers to the amount of power that can be delivered per unit volume or weight. Generally, primary cells have higher energy density but lower power density compared to secondary cells. This means secondary cells can often deliver higher currents (more power) for short periods, making them suitable for high-drain devices.

33. What is the significance of the "cut-off voltage" in battery operation?

The cut-off voltage is the minimum voltage at which a battery can operate effectively. It's important for both types but especially crucial for secondary cells. Discharging a secondary cell below its cut-off voltage can cause irreversible damage. Many devices with rechargeable batteries have built-in protection to prevent discharge below this voltage.

34. How do primary and secondary cells handle "pulse discharge" differently?

Pulse discharge refers to short bursts of high current draw. Primary cells, especially those designed for high-drain applications, can often handle pulse discharges well. Secondary cells, particularly lithium-ion, are generally better suited for frequent pulse discharges due to their lower internal resistance and ability to recover between pulses.

35. What is meant by the "nominal voltage" of a battery, and how does it relate to cell chemistry?

Nominal voltage is the reference voltage of a battery, often used to categorize it. It's closely related to the cell chemistry. For example, alkaline primary cells have a nominal voltage of 1.5V, while lithium-ion secondary cells typically have a nominal voltage of 3.6V or 3.7V. The actual voltage varies during discharge but centers around this nominal value.

36. What is a "flow battery" and how does it differ from conventional primary and secondary cells?

A flow battery is a type of rechargeable battery where the energy is stored in two chemical components dissolved in liquids contained within the system and separated by a membrane. Unlike conventional secondary cells, the electrolyte is stored externally and pumped through the cell. This allows for easy scaling of capacity by simply using larger tanks of electrolyte.

37. How do primary and secondary cells differ in their ability to deliver high currents?

Secondary cells generally have a better ability to deliver high currents due to their lower internal resistance. This makes them suitable for high-drain devices. Primary cells, while capable of high currents in some designs (like alkaline), are often optimized for longer, steady discharge rather than high current output.

38. What is the "Peukert effect" and how does it apply to different types of batteries?

The Peukert effect describes how the capacity of a battery decreases when it's discharged at a higher rate. It's more pronounced in lead-acid secondary cells but also affects other types to varying degrees. Primary cells are less affected by this phenomenon as they're typically not used in applications requiring widely varying discharge rates.

39. How do the anode and cathode materials differ between primary and secondary cells?

In primary cells, anode and cathode materials are chosen for their ability to produce energy efficiently in one direction. In secondary cells, these materials must also be capable of reversing the chemical reaction. For example, a lithium-ion battery uses materials like graphite and lithium cobalt oxide that can repeatedly insert and remove lithium ions.

40. What is meant by the "energy efficiency" of a battery, and how does it compare between primary and secondary cells?

Energy efficiency in batteries refers to the ratio of energy output to energy input. For primary cells, this is essentially 100% as all stored energy is available for use. Secondary cells have lower energy efficiency due to losses during charging and discharging processes. Lithium-ion batteries, for instance, typically have an energy efficiency of 80-90%.

41. How does the concept of "cycle life" apply to primary and secondary cells?

Cycle life refers to the number of charge-discharge cycles a battery can undergo before its capacity falls below a certain percentage of its original capacity. This concept is primarily applicable to secondary cells, as primary cells are not designed for multiple cycles. Different types of secondary cells have varying cycle lives, with lithium-ion typically ranging from 500 to 1000+ cycles.

42. What is a "smart battery" and how does it relate to primary and secondary cells?

A smart battery is a rechargeable battery pack that includes a built-in microchip to manage and monitor its operation. This technology is exclusively used with secondary cells, providing features like accurate state of charge estimation, health monitoring, and optimized charging. Primary cells do not incorporate such advanced management systems.

43. How do primary and secondary cells compare in terms of their ability to function in extreme temperatures?

Primary cells generally perform better in extreme temperatures, especially cold conditions. Many types of primary cells can operate effectively in a wider temperature range. Secondary cells, particularly lithium-ion, are more sensitive to temperature extremes. Very low temperatures can significantly reduce their capacity, while high temperatures can accelerate degradation and pose safety risks.

44. What is the "float voltage" in battery charging, and how is it relevant to different cell types?

Float voltage is the voltage at which a fully charged battery is maintained to compensate for self-discharge. This concept is primarily relevant to secondary cells, particularly lead-acid batteries. It's not applicable to primary cells as they are not recharged. Proper float voltage is crucial for maintaining secondary cells in a fully charged state without overcharging.

45. How do primary and secondary cells differ in their susceptibility to "thermal runaway"?

Thermal runaway is a situation where an increase in temperature causes further increase in temperature, potentially leading to destructive results. It's a more significant concern with secondary cells, particularly lithium-ion batteries, due to their higher energy density and the presence of flammable electrolytes. Primary cells are generally less prone to thermal runaway, though they can still be dangerous if severely overheated.

46. What is a "trickle charge" and how does it relate to different battery types?

Trickle charging involves charging a battery with a current roughly equal to its self-discharge rate, maintaining a full charge. It's primarily used with certain types of secondary cells, like nickel-cadmium or lead-acid batteries. It's not applicable to primary cells and can be harmful to some types of secondary cells like lithium-ion, which prefer different charging methods.

47. What is the "memory effect" in batteries, and which types of cells are affected by it?

The memory effect is a phenomenon where certain rechargeable batteries appear to "remember" smaller capacities if they are repeatedly recharged after only partial discharge. It primarily affects nickel-cadmium (NiCd) secondary cells and, to a lesser extent, nickel-metal hydride (NiMH) batteries. It doesn't affect primary cells or lithium-ion secondary cells.

48. What is a "hybrid" battery system, and how does it incorporate aspects of both primary and secondary cells?

A hybrid battery system combines different types of batteries or energy storage technologies to leverage the advantages of each. For example, a system might use high-energy-density primary cells for long-term, low-drain applications alongside rechargeable secondary cells for high-power, frequent-use needs. This approach aims to optimize performance, lifespan, and cost-effectiveness.

49. How do primary and secondary cells differ in their ability to handle "pulse charging"?

Pulse charging involves charging a battery with pulses of current rather than a steady stream. This method is primarily used with certain types of secondary cells, like lead-acid or nickel-based batteries, to improve charging efficiency and battery life. It's not applicable to primary cells, which are not designed to be recharged at all.