Daniell Cell Battery Isaac Favila - Professor Scarbrough - CHM152LL History ● Invented in 1836 by John Frederic Daniell ● Precursor was voltaic cell ○ Invented by Luigi Galvani in 1799 ● One of the first practical batteries ever invented John Frederick Daniell History ● A great improvement to the voltaic cell ○ Longer lifespan due to the materials having a slower rate of corrosion ○ Voltaic cell was not reliable for long term use ● Was popular for powering telegram systems A 19th century Daniell Cell How does it work? Two Versions: Salt bridge separation Separation by porous barrier How does it work? Salt Bridge: ● Copper electrode placed in copper sulfate (CuSO4) solution ● Zinc electrode placed in zinc sulfate (ZnSO4) solution ● Bridged together by salt bridge made of potassium nitrate (KNO3) How does it work? Porous barrier: ● This time zinc solution is placed inside the copper solution ● The copper electrode is instead a copper strip ● The barrier separating the copper and zinc is porous to allow the solutions to interact How does it work? ● Zinc electrode oxidizes and releases electrons 2+ - Oxidation Reaction: Zn(s) ⟶ Zn (aq) + 2e ● The copper electrode pulls the excess electrons through the conducting material, creating a circuit 2+ - Reduction reaction: Cu (aq) + 2e ⟶ Cu(s) ● The salt bridge releases ions to balance the loss of Cu2+ and increase in Zn2+ Voltage ● Standard potential difference of 1.1 V ○ Copper reduction potential is +0.340V Solution ○ Zinc reduction potential is -0.762V Amount (Both Potential Solutions) Difference ● Table shows examples potential differences of 50ml 1.082V real-world Daniell Cells 20ml 0.92V 120ml 1.06V 250ml 1.053V 250ml 1.024V Works Cited “Daniell Cell.” Daniell Cell - Engineering and Technology History Wiki, Engineering and Technology History, 19 Feb. 2020, ethw.org/Daniell_Cell. “Daniell Cell.” MagLab, MagLab, 17 June 2019, nationalmaglab.org/education/magnet-academy/watch- play/interactive/daniell-cell. da Rosa, Aldo. “Daniell Cell.” Daniell Cell - an Overview , ScienceDirect, 27 Mar. 2013, www.sciencedirect.com/topics/engineering/daniell-cell. Roberge, Pierre R. “Daniell Cell.” Daniell Cell, Kingston Technical Software, 18 Nov. 2007, corrosion- doctors.org/Electrochemistry-of-Corrosion/Daniell-cell.htm. “Voltaic Pile.” MagLab, MagLab, 17 June 2019, nationalmaglab.org/education/magnet-academy/watch- play/interactive/voltaic-pile..