Silver oxide/button cell help (1 Viewer)

[student5]

I need to explain how a silver oxide/button cell works in relation to its chemistry. I cannot find for the life of me any useful information on this, could someone please help!!

 

[captainhelium]

Hopefully this helps!

Reaction at anode which is composed on Zn

Oxidation: Zn_(s) + 2OH^-_(aq) --> ZnO_(s) + H₂O_(l) + 2e^-

Reaction at cathode which is composed of Ag₂O

Reduction: Ag₂O_(s) + H₂O_(l) + 2e^- --> 2Ag_(s) + 2OH^-_(aq)

And overall reaction is,

Zn_(s) + Ag₂O_(s) --> 2Ag_(s) + ZnO_(s)

And the electrolyte is potassium hydroxide (KOH) and the net cell potential is 1.5V

 

[student5]

Thank you, this helps heaps! Would you also happen to have an actual explanation as to what is going on? I have also done the same thing for a lead acid cell and talked about how the ions move throughout the battery etc. Would you have any information similar to that?

 

[captainhelium]

Thank you, this helps heaps! Would you also happen to have an actual explanation as to what is going on? I have also done the same thing for a lead acid cell and talked about how the ions move throughout the battery etc. Would you have any information similar to that?

No worries. I think what happens is you have KOH as your electrolyte in a porous medium within the middle of the button cell. Zinc acts as an anode on one end of the cell and silver oxide is the cathode at the other end of the cell. The Zinc basically reacts with the OH^- ions from the KOH electrolyte to form Zinc Oxide, water and releases two electrons which travels within the electrolyte I think. This is the oxidation process

The silver oxide then uses these two electrons from the oxidation of zinc and also reacts with water to form silver solid and hydroxide ions (which probably are released back into the KOH electrolyte).

These oxidation and reduction reactions consequently result in electrochemical cell being formed which have a net voltage of 1.5 V.

Perhaps this following diagram can help you visualise the actual structure of it a bit better:

https://dc.edu.au/wp-content/uploads/silver-oxide-button-cell.png

 

[student5]

Sorry I never got to reply but thank you very much