Methanol-based thermoelectric conversion device with high power

A liquid thermoelectric conversion device (LTE) converts environmental heat into electric power via the electrochemical Seebeck coefficient α. The maximum power (W_max) is expressed as $W_{max}=\frac{{\alpha }^2\mathrm{\Delta }{T}^2}{4R^{\mathrm{\prime }}}$, where ΔT and R′ are the temperature difference between electrodes and device resistance in operation, respectively. Here, we systematically investigated the resistance components of LTEs composed of aqueous, methanol (MeOH) and acetone solutions containing 0.8 M Fe(ClO₄)₂/Fe(ClO₄)₃. We found that the charge transfer resistance R_ct of the MeOH LTE is the smallest among the three LTEs. We demonstrated that the W_max of the MeOH LTE is slightly larger than or comparable with that of the corresponding aqueous LTE. We further discussed the effects of the convection of an electrolyte on R′.