Direct Thermal-to-Electrochemical Energy Conversion Via A Pyroelectrochemical Cell

This work demonstrates a novel concept for the direct conversion of thermal energy to stored electrochemical energy that the authors call a “pyroelectrochemical cell” (PEC). The PEC uses a porous pyroelectric material as the separator of supercapacitor. Thermal energy (in the form of a temperature change with time) generates a voltage across the separator, which induces ion migration and charges the cell. Experimental results validate the device concept by demonstrating the separator’s dual functionality as pyroelectric material and porous membrane. A PEC with pyroactive separator was held at 50 mV and heated from 20 to 30
^o
C at a rate of 0.336 °C/min. When the separator pyroelectric field is oriented with positive dipole at the anode, chronoamperometric current increases by 155% due to heating, generating 9.66 mJ over the one-hour test. In a separate heating test (50 mV, 20 to 55
^o
C), when the separator orientation is reversed, changing the direction of the heating induced electric field, chronoamperometric current decreases from 15.3 μA to 5.2 μA, indicating the expected directional response of the pyroelectric separator.