The equations show the standard electrode potentials of the half-cells used in a lithium iron phosphate cell:
Li++e−⇌LiE⊖=−3.04 V \text{Li}^+ + \text{e}^- \rightleftharpoons \text{Li} \quad E^{\ominus} = -3.04\text{ V} Li++e−⇌LiE⊖=−3.04 V FePO4+Li++e−⇌LiFePO4E⊖=+0.36 V \text{FePO}_4 + \text{Li}^+ + \text{e}^- \rightleftharpoons \text{LiFePO}_4 \quad E^{\ominus} = +0.36\text{ V} FePO4+Li++e−⇌LiFePO4E⊖=+0.36 VWhich statement is correct for this cell during discharge?
The cell potential is 2.68 V2.68\text{ V}2.68 V.
The reaction at the positive electrode is: LiFePO4→FePO4+Li++e−\text{LiFePO}_4 \rightarrow \text{FePO}_4 + \text{Li}^+ + \text{e}^-LiFePO4→FePO4+Li++e−.
The overall cell reaction is: Li+FePO4→LiFePO4\text{Li} + \text{FePO}_4 \rightarrow \text{LiFePO}_4Li+FePO4→LiFePO4.
The oxidation number of Fe\text{Fe}Fe changes from +2 to +3.
