1. The Zinc-Carbon Battery
By Catherine & Calvin

2. The Zinc-Carbon Battery
also called as LeClanche-Cell, Common Dry Cell
produced by George Leclanché in 1866
the first cell to contain only one low-corrosive fluid electrolyte with a solid cathode.

3. The Zinc-Carbon Battery (p231)
Characteristics in brief
Voltage: 1.5 – 1.75 V
Service Life: 110 min (continuous use)
Shelf life: ~ 1 – 2 years (at room temperature)

4. The Zinc-Carbon Battery
Paste made of NH4Cl, MnO2 and graphite

5. Carbon rod Inserted into the cathode Acts as a current collector
Retain moisture
Provides structural support
Not take part in reaction

6. Cathode mix Composed with NH4Cl, MnO2 and graphite (a form of carbon)
ammonium chloride(NH4Cl) acts as a fuel reserve for the cell during intermittent operation
The Cathode ½ Reaction:
2NH4+(aq) + 2MnO2(s) + 2e– → 2MnO(OH)(s) + 2NH3(aq)

7. Anode-Zinc Zn (s)+ 4NH3(aq) → Zn(NH3)42+(aq)+ 2e–
Most dry cells combine zinc with mercury (less than 1 part per million in modern cells)
to significantly improve its resistance to corrosion over times.
As the Zn is used up and Zn(NH3)42+ accumulates around the anode, the battery “wears out” and the voltage decreases.
The Anode ½ Reaction:
Zn (s)+ 4NH3(aq) → Zn(NH3)42+(aq)+ 2e–

8. The Zinc-Carbon Battery
Disadvantages
1) After using for a long time, the chemicals would leak out of the battery, it is not good for the environmental protection
2) it cannot be recharged
3) lifetime is short because it continually reacts at a slow rate
4) current is small (it ceases to function if required to produce large currents in short time)
5) voltage is not stable
6) resistance is high

9. The Zinc-Carbon Battery
Advantages
Cheap
Convenient
Usage:
1)flashlights
2)clock
3)toy
4)radio

10. Bibliography “Zinc-Carbon Batteries”,
28th Jan. 2003, 28th Dec.2011
‘‘Zinc/carbon batteries”,
no publish date, 28th Dec.2011
“Zinc–carbon battery”,
10th Dec.2011, 28th Dec.2011
2010, 28th Dec.2011