Figure 1.

Schematic representation of two electric fields in a thermocell. The internal electric field ${\overrightarrow{E}}_{\mathrm{int}}$ is created in the solution volume by thermodiffusion of ions. The thermogalvanic electric field $\overrightarrow{E}$ is created between the two electrodes. The hot and cold electrode potentials are ${\mathcal{V}}_{\mathrm{hot}}$ and ${\mathcal{V}}_{\mathrm{cold}}$ : $\left|\overrightarrow{E}\right|=\left|\frac{{\mathcal{V}}_{\mathrm{hot}}-{\mathcal{V}}_{\mathrm{cold}}}{l}\right|$, l being the distance between the electrodes.Electric field in a thermocell