The Alkaline Dry Cell


Alkaline Dry Cell - Voltage 1.5 volts

This cell also uses a zinc can for the anode and its outside casing. The cathode post is made of manganese dioxide (MnO2). The electrolyte paste is potassium hydroxide (KOH). The cost of the materials is generally higher than the zinc-carbon cell but the major benefits are the longer operational life and longer shelf life. As the cell nears its end-of-life it may start to leak. Be cautious when working with any leaking cell because the potassium hydroxide is caustic. This cell is not re-chargeable. This means the chemical reaction can not be reversed by using electricity.

       

     Chemically this oxidation reduction reaction takes place.
   
          Zn + 2 MnO2  +  H2O   - - - >  Mn2O3  +  Zn(OH)2-  2e-