5
$\begingroup$

Strontium has a very low standard electrode potential and fluorine has a very high one.

$$ E_{\ce{F2 + 2e^- -> 2F^-}} = 2.87\mathrm{V} $$ $$ E_{\ce{Sr -> Sr^+ + e^-}} = -4.10\mathrm{V} $$

In theory a strontium-fluorine battery would have a voltage of $6.97\mathrm{V}$ although there are many practical reasons such as danger and rarity of materials for such batteries not to be made.

Is a strontium-fluorine battery the theoretically highest voltage chemical battery using pure elements or is it possible to obtain a higher one?

|improve this question
$\endgroup$
  • $\begingroup$ You could always change the concentrations to change the EMF. But, if fluorine and strontium are indeed at the extreme opposites, you are right. $\endgroup$ – Yunfei Ma Mar 31 '16 at 3:18
7
$\begingroup$

The half-potential you've given for strontium is only for the first ionisation. The half-potential you'd actually get is -2.899V for the stable dication to give a cell potential of 5.769V. From the CRC Handbook[1], lithium has the lowest element->stable ion potential of -3.0401V, which is why it's common in batteries.

[1]: Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.

|improve this answer
$\endgroup$
  • $\begingroup$ Can more exotic stuff such as electrides, halides and alkalides achieve higher potentials? The only standard electrode potential I can find for one of these strange anions is for the hydride anion which is 2.23V which is still not better than flourine. $\endgroup$ – Steven Stewart-Gallus Apr 7 '16 at 0:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.