Large harvested energy with non-linear pyroelectric modules

Coming up with sustainable sources of electricity is one of the grand challenges of this century. The research field of materials for energy harvesting stems from this motivation, including thermoelectrics(1), photovoltaics(2) and thermophotovoltaics(3). Pyroelectric materials, converting temperature periodic variations in electricity, have been considered as sensors(4) and energy harvesters(5-7), although we lack materials and devices able to harvest in the joule range. Here we develop a macroscopic thermal energy harvester made of42 g of lead scandium tantalate in the form of multilayer capacitors that produces11.2 J of electricity per thermodynamic cycle. Each pyroelectric module can generate up to 4.43 J cm(-3) of electric energy density per cycle. We also show that two of these modules weighing 0.3 g are sufficient to sustainably supply an autonomous energy harvester embedding microcontrollers and temperature sensors. Finally, we show that for a 10 K temperature span these multilayer capacitors can reach 40% of Carnot efficiency. These performances stem from (1) a ferroelectric phase transition enabling large efficiency, (2) low leakage current preventing losses and (3) high breakdown voltage. These macroscopic, scalable and highly efficient pyroelectric energy harvesters enable the reconsideration of the production of electricity from heat.

Automated summary

A new type of macroscopic thermal energy harvester has been proposed, which can convert heat into electricity, making significant contributions to sustainable energy. This harvester has high efficiency and high electric energy density, capable of sustainably powering microcontrollers and sensors.