Non-linear pyroelectric energy harvesting with commercial multilayer capacitors

Pyroelectric materials enable the transformation of periodic temperature variations into electrical power, offering a promising and sustainable electricity source. To date, several pyroelectric materials have been tested for waste heat harvesting, including ceramics such as lead scandium tantalate, which showed the highest performance when used in multilayer capacitors. However, these custom-made optimized capacitors are available in limited quantities, which questions their possible use in future large heat harvesters. Here, we investigate the potential of largely available industrially manufactured multilayer capacitors for non-linear pyroelectric heat harvesting. We first present an electrical screening of several of these capacitors, measuring their breakdown voltage, losses and theoretical harvested energy density for a given Olsen cycle. The best sample presents a maximum active energy density of 3.7 J cm^-3 for a cycle run over a temperature span of 200 °C and under an applied voltage of 450 V. Then, characterization shows that this multilayer capacitor is made of Ca and Zr-doped BaTiO₃, with a Curie temperature of 10 °C. Finally, the capacitor's performance is evaluated in the context of a prospective heat harvesting device, confirming its potential as a viable candidate for non-linear pyroelectric energy harvesting.