Using the expressions for the chemical potentials in the negative (equation 4.24) and positive (equation 4.22) electrodes, we substitute them into equation (4.6) for the voltage:

An example voltage plot is shown in Figure 4.10. Note that because of the logarithmic term (due to configurational entropy), the voltage diverges (tends to infinity) as $X \to 0$. In practical terms, it is impossible to completely remove all Li from the positive electrode (i.e. to charge a battery to 100%) because doing so would require an infinite amount of energy.