Large harvested energy with non-linear pyroelectric modules

Area of Science:

• Materials Science
• Energy Harvesting
• Solid State Physics

Background:

• Sustainable electricity generation is a critical global challenge.
• Pyroelectric materials convert temperature variations into electricity, but lack joule-range harvesting capabilities.
• Existing materials and devices are insufficient for large-scale thermal energy harvesting.

Purpose of the Study:

• To develop a macroscopic pyroelectric thermal energy harvester capable of joule-range electricity generation.
• To demonstrate the potential of pyroelectric materials for powering autonomous devices.
• To achieve high energy conversion efficiency using pyroelectric multilayer capacitors.

Main Methods:

• Fabrication of a macroscopic thermal energy harvester using 42g of lead scandium tantalate in multilayer capacitor form.
• Characterization of the device's electricity output per thermodynamic cycle and energy density.
• Testing the harvester's ability to power an autonomous energy system with microcontrollers and sensors.
• Evaluation of energy conversion efficiency relative to Carnot efficiency.

Main Results:

• The harvester produces 11.2 J of electricity per thermodynamic cycle.
• Individual pyroelectric modules achieve an energy density of 4.43 J cm⁻³ per cycle.
• Two small modules (0.3g) can sustainably power an autonomous energy harvester.
• An efficiency of 40% of Carnot efficiency is reached for a 10 K temperature span.

Conclusions:

• Macroscopic, scalable, and efficient pyroelectric energy harvesters are now feasible.
• These devices offer a promising avenue for generating electricity from heat.
• The high performance is attributed to a ferroelectric phase transition, low leakage current, and high breakdown voltage.