Calculating the reaction energy in a Lithium Iron Phosphate battery

[Kerrowman]

Can anyone help me calculate the Gibbs free reaction energy in a Lithium Iron Phosphate battery with the combined equation?

LiC₆ + FePO₄   →   C₆ + LiFePO₄  

Since the Lithium ions are acting as intermediaries and are on both sides, I understand that they can be removed from the equation.

Since the formation energies of all these molecules are not listed in any tables I can find, I presume I have to work from the components of each molecule, so using the Gibbs formation energies of Li⁺, C₆, Fe⁺, Fe²⁺ and PO₄^3-, before I can use the combined equation above? 

For example to get the ΔG°_f (FePO₄) do I use the equation:

Fe³⁺ + PO₄^3-  →  FePO₄  and then just add the ΔG^o_f Reactants together, which would be -5 + (-1019) kJ/mol

I have found the following formation energies so far:

ΔG°(Li⁺) = -58kJ/mol, ΔG°(C) = 0kJ/mol (standard state?), ΔG°(Fe²⁺) = -79kJ/mol, 

ΔG°(Fe3⁺) = -5kJ/mol and ΔG°(PO₄^3-) = -1019kJ/mol

For the combined equation I then need to use ΔG°r = 𝛴 ΔG^o_f Products  - 𝛴 ΔG^o_f Reactants, however I am not clear how to get the formation energies of all the components in the first place.

Thanks

[Harry_-]

Sorry I don't have lots of time to write a reply at the moment I'm working on a lab. However if you can find the redox potentials for the cell you could use:

 

ΔG^o= nFE

n is the number of moles used in the balanced equation

F is faraday's constant of 96500 Cmol^-1

E is your cell potential under standard conditions (reduction - oxidation potentials)

 

If you need help ask or there are lots of good online videos on that equation.

 

Regards,

Harry

[StringJunky]

I'll @Kerrowman as that should send them a note you have responded, if they have notifications enabled..