Pyroelectric Energy Harvesting Research Articles

Electronic cooling and energy harvesting using ferroelectric polymer composites

Thermal management emerges as a grand challenge of next-generation electronics. Efforts to develop compact, solid-state cooling devices have led to the exploration of the electrocaloric effect of ferroelectric polymers. Despite recent advances, the applications of electrocaloric polymers on electronics operating at elevated temperatures remain essentially unexplored. Here, we report that the ferroelectric polymer composite composed of highly-polarized barium strontium titanate nanofibers and electron-accepting [6,6] phenyl-C61-butyric acid methyl ester retains fast electrocaloric responses and stable cyclability at elevated temperatures. We demonstrate the effectiveness of electrocaloric cooling in a polymer composite for a pyroelectric energy harvesting device. The device utilizes a simulated central processing unit (CPU) as the heat source. Our results show that the device remains operational even when the CPU is overheated. Furthermore, we show that the composite functions simultaneously as a pyroelectric energy converter to harvest thermal energy from an overheated chip into electricity in the electrocaloric process. This work suggests a distinct approach for overheating protection and recycling waste heat of microelectronics.

Optimized pyroelectric behaviors by constructing the nonergodic-ergodic transition state

Bi0.5Na0.5TiO3 (BNT)-based relaxors are considered as potential candidates for pyroelectric applications due to their excellent pyroelectric performances. However, the excellent pyroelectric response in BNT-based relaxors is generally accompanied by a rapid decrease in the depolarization temperature Td, limiting the operation temperature. Herein, we find that the mixed non-ergodic and ergodic relaxor states (a kind of transition system) can promote polarization rotation and remain the reversibility of polarization transformation simultaneously, thereby improving pyroelectric performances and maintaining the Td . The Li+-doped BNKT-based relaxors which possess such a transition state exhibit excellent room temperature (RT) pyroelectric coefficients (1247 μCm−2K−1), and also, the Td can maintain at 69℃. This work provides a strategy for further insight into the enhanced pyroelectric response, which promotes the development of eco-friendly pyroelectric applications (such as infrared detection, temperature sensors, and pyroelectric energy harvesting).

Large pyroelectric energy conversion in lead scandium tantalate thin films

Non-linear pyroelectric energy harvesting using ferroelectric thin films exhibits high energy conversion, primarily due to their large breakdown field compared to bulks. Here, we report the pyroelectric energy conversion potential of lead scandium tantalate, Pb(Sc1/2Ta1/2)O3 (PST) thin film fabricated on a c-sapphire substrate using chemical solution deposition. To enable the application of high electric field and to assess the pyroelectric energy conversion performance, interdigitated electrodes were deposited on the PST thin film. A maximum harvested energy density of 9.1 J cm−3 per cycle was deduced from polarization measurements in films undergoing an Olsen cycle between 0 °C and 150 °C when the electric field was varied between 50 and 1500 kV/cm. Furthermore, PST thin films can reach up to 27 % of Carnot efficiency for a temperature interval of 10 K between 30 °C and 40 °C. This study highlights the significance of PST thin films for electro-thermal energy harvesting and promising opportunities for enhancing the conversion efficiency and power density using thin films or thin film multi-layer capacitors in the future for thermal energy harvesting.

Potentials and Limits of PMN-PT and PIN-PMN-PT Single Crystals for Pyroelectric Energy Harvesting

Waste heat is inherent to industrial activities, IT services (e.g., data centers and microprocessors), human mobility, and many other common processes. The power lost each year in this way has been estimated in the 1000 TWh in the EU which, owing to skyrocketing energy prices and not least the urgent need for decarbonizing the economy, has engendered tremendous research efforts among scientists and engineers to recover/recycle this waste energy. Beyond established thermal engineering solutions for waste heat, advances in multifunctional materials open new paradigms for waste heat harvesting. Two smart material types are of particular focus and interest at present; these are thermoelectric and pyroelectric materials, which can both transform heat to electrical power, though via different effects. The present paper summarizes our research work on a new class of pyroelectric materials, namely <111> oriented (1-x)(Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN-PT) and x-Pb(In1/2 Nb1/2)O3-y-Pb(Mg1/3 Nb2/3)O3-(1-x-y)-PbTiO3 (PIN-PMN-PT) single crystals that exhibit some of the highest pyroelectric properties ever measured. First, a figure of merit for pyroelectric energy harvesting is derived, followed by a detailed assessment of the properties of the said crystals and how they depend on structure, poling, thickness, and temperature. The properties are further contrasted with those of conventional pyroelectric crystals. It is concluded that the PMN-PT-base single crystals are best suited for harvesting devices with a working temperature range from 40 to 100 °C, which encompasses waste heat generated by data centers and some chemical and industrial processes, affording the highest figure of merit among pyroelectric materials.

Antimony Sulfoiodide‐Based Energy Harvesting and Self‐Powered Temperature Detection

The ferroelectric‐semiconductor behavior of antimony sulfoiodide (SbSI) has opened up the material as a base for energy‐harvesting devices. Specifically, SbSI has drawn much attention for pyroelectric energy harvesting and thermal sensing with outstanding electrothermal properties. This work investigates the thermistor properties of an SbSI material and presents the development of an SbSI nanorod/Kapton‐based triboelectric nanogenerator (TENG) for effective energy harvesting and temperature sensing. The TENG based on SbSI/ Kapton operating in vertical contact separation mode delivers a peak‐to‐peak voltage of 90 V and a current of 1510 nA, respectively. Introducing SbSI nanorods for TENG opens the possibility of extending the conventional triboelectric series. The electrical and dielectric properties of the SbSI nanorods are investigated. SbSI exhibits a highly linear temperature coefficient of resistance (TCR) of −0.026 °C−1, making it an excellent candidate material for a thermistor. In addition, the material exhibits an excellent thermal sensitivity (β20/80 = 1612.1 K). For demonstration, the SbSI thermistor is connected with TENG, and the outputs at various temperatures are analyzed for self‐powered temperature sensing. This capability allows for efficient temperature monitoring without relying on external power sources, advancing remote, and autonomous sensing applications.

Layered porous Na0.5Bi0.5TiO3-0.06BaTiO3 for enhanced pyroelectric thermal energy harvesting

Layered Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-6BT) ceramics of dense-porous-dense structure along the thickness are fabricated. The porous layer is sandwiched between the top and bottom dense layer, nullifying the electrode material's seepage into pores. Thus, porous pyroelectric material reduces the dielectric breakdown during poling and increases the repeatability of the poling process. The burnt-out polymer technique creates 10.7 %, 14.23 %, 21.3 % and 28 % porosity. The dielectric constant in layered porous structure decreased from 785 to 221 as the porosity increased from 5.4 % (pure NBT-6BT) to 28 % (layered NBT-6BT-12) at room temperature (poled condition). The introduction of porosity showed an increment of 124 % in the modified pyroelectric energy harvesting figure of merit Fe* for NBT-6BT-12 at 80 °C. The real-time thermal energy harvesting obtained by heating and cooling the pyroelectric material demonstrated equivalent voltage for NBT-6BT-12 layered porous structure. The layered porous structure can be a viable alternative for enhanced voltage sensitivity and energy harvesting.

Thermoelectric coupling effect in BNT-BZT-xGaN pyroelectric ceramics for low-grade temperature-driven energy harvesting

Pyroelectric energy harvesting has received increasing attention due to its ability to convert low-grade waste heat into electricity. However, the low output energy density driven by low-grade temperature limits its practical applications. Here, we show a high-performance hybrid BNT-BZT-xGaN thermal energy harvesting system with environmentally friendly lead-free BNT-BZT pyroelectric matrix and high thermal conductivity GaN as dopant. The theoretical analysis of BNT-BZT and BNT-BZT-xGaN with x = 0.1 wt% suggests that the introduction of GaN facilitates the resonance vibration between Ga and Ti, O atoms, which not only contributes to the enhancement of the lattice heat conduction, but also improves the vibration of TiO6 octahedra, resulting in simultaneous improvement of thermal conductivity and pyroelectric coefficient. Therefore, a thermoelectric coupling enhanced energy harvesting density of 80 μJ cm−3 has been achieved in BNT-BZT-xGaN ceramics with x = 0.1 wt% driven by a temperature variation of 2 oC, at the optical load resistance of 600 MΩ.

Thermodynamics and Ferroelectric Properties of Pb1-xSrxTiO3 Solid Solutions

Pb1-xSrxTiO3 solid solutions have been utilized to compositionally tune the phase transitions and ferroelectric properties and thus are attractive for potential applications in tunable microwave devices and pyroelectric energy harvesters. However, a reliable thermodynamic description of the Pb1-xSrxTiO3 system is currently lacking. Here, we establish a thermodynamic free energy density function for the Pb1-xSrxTiO3 solid solution system taking into account both the polarization and octahedral tilt, and validated it by reproducing the experimentally measured polarization, lattice parameters, and dielectric constant values. Based on the thermodynamic model, we successfully explain the experimentally observed dielectric anomalies by analyzing the interactions between ferroelectric and octahedral tilt order parameters and constructed a comprehensive temperature-composition Pb1-xSrxTiO3 phase diagram which can be used to guide future experimental synthesis and thin film growth. The thermodynamic model developed in this work can be employed not only to predict the ferroelectric and structural states and their properties for compositions that have not yet been synthesized but also used as input to model the formation of mesoscale domain structures using the phase-field method.

Porous pyroelectric material for waste heat harvesting

The utilization of pyroelectric materials to harvest waste heat from the ambient environment has gained much interest. However, pyroelectric energy harvesting technology still faces the challenge of low output voltage. In this paper, a porous pyroelectric ceramic with 0.3 wt.% poly(methyl methacrylate) (PMMA) as the additive was prepared via a conventional solid-state reaction technique. Our experimental results indicated that the porous PMN–PMS–PZT:0.3PMMA ceramic had a decrease in both relative permittivity and volume heat capacity at a temperature of 44ˆ∘C, compared to that of the dense sample. Additionally, the porous ceramic demonstrated an enhanced voltage responsivity from 0.50 to 0.52 m2/C and a higher figure of merit from 0.64 to 0.65 nm3/J for energy harvesting, compared to the dense sample. When 0.3 wt.% PMMA was added, the voltage generated by the device increased by 17.01% due to the presence of pores, which suggests a potential application in the field of waste heat harvesting and sensing.

Enhancement of a pyroelectric body energy harvesting scheme employing pulsed electric fields.

This research utilizes waste heat energy as a sustainable energy source to enhance pyroelectric power output by combining pyroelectric nanogenerators with an external pulsed electric field. When the surface temperature of the pyroelectric body varies, applying different pulses of the external electric field results in maximum power accumulation. A novel power-generating experimental setup was developed to measure and compute pyroelectric power generation. A standard Fuji ceramic C-9 sample was used to generate pyroelectric energy in a 20 °C temperature range from 120 to 140 °C. The continuous temperature variation frequency was 0.05Hz, and the pulsed electric field was applied when the temperature rose. Pulses of the electric field with widths of 10, 50, 100, and 200ms were applied to the sample under different pulse amplitudes, and the amplitude of each pulse was 250, 500, 1000, or 1500 V/mm. The maximum power generated through the application of an external pulsed electric field under the above-mentioned conditions was evaluated. This system had the highest power density of 0.204 mJ cm-2 °C-1kV-1. In addition, for the lowest input power, the maximum power generation condition was a 10ms pulse width and an amplitude of 250Vmm-1 in the applied electric field. This state might power smart sensor modules, IoT devices, automobiles, and other waste heat energy applications. Nano-pulse electric field applications may reduce input power to its lowest level, dependent on net-producing power. Therefore, new researchers can use net-generation power efficiency to create a large-scale power source using multiple pyroelectric arrays.

Relaxor-antiferroelectric hybrids for pyroelectric energy conversion from low-grade heat using flexible PVDF-TrFE-CTFE-NaNbO3 nanocomposite films

Nowadays, researchers focus more on developing smart materials that respond to different stimuli for harvesting energy output. In this paper, the pyroelectric energy harvesting capabilities of smart terpolymer poly(vinylidene-fluoride-trifluoroethylene-chlorotrifluoroethylene) [PVDF-TrFE-CTFE]-based nanocomposites have been investigated. Sodium niobate (NaNbO3) from the perovskite family is selected as the filler. The Sol-gel method is used to synthesise NaNbO3 nanoparticles, and solvent-cast films for different weight fractions (0–20%) of fillers have been fabricated. Structural, morphological, and dielectric properties of the polymer nanocomposite samples were done at room temperature. The ferroelectric properties of the terpolymer is improved with filler addition. The thermal stability of composite films was confirmed using differential scanning calorimetric (DSC) studies. The thermodynamic Olsen cycle was applied to nanocomposites for calculating the harvested energy output. Maximum energy density is obtained for higher filler loading (20 wt % sodium niobate). The operating temperatures were selected at 303 K and 333 K with an applied field of 130 kV/cm. The results show that including NaNbO3 in the relaxor terpolymer matrix considerably enhances the energy harvesting density of the nanocomposites, indicating that they are promising materials for designing thermally stable energy harvesting systems.

Pyroelectric energy harvesting from power electronic substrates

Energy harvesting from available resources can lead to implementation of more controlling and actuating devices for industrial internet of things (IIoT). Energy harvesting from temperature fluctuations in power electronic devices by pyroelectric materials is a key solution to achieve self-powered sensor systems. In this study, performance of a pyroelectric energy harvester (PEH), utilized as a dielectric substrate in power electronic modules, is investigated. Accordingly, a comprehensive analytical model is developed in MATLAB software, and the theoretical results are validated with experimental data. The results of this study show that, the pyroelectric substrate can harvest an average power of 50 µW/cm2. Effect of amplitude and frequency of input heat, cooling density, and load resistance over PEH are studied. The results reveal that, frequency of the input heat rate higher than 2 Hz does not have a sensible impact on the power generation by the pyroelectric module. Convective cooling density with low heat transfer coefficients led to higher power generation. On the contrary, it can cause operating at higher temperature than the Curie temperature. The energy harvesting concept developed, for the first time, in this study shows significant potential of pyroelectric direct bonded copper substrate to provide self-powered sensors for IIoT in a vast range of power electronic applications.

Enhanced pyroelectric properties of BNT-xBNN lead-free ferroelectric ceramics for energy harvesting

Pyroelectric energy harvesting has been explored to obtain high room temperature pyroelectric coefficient (p) along with high depolarization temperature (Td) for the practical applications. However, the problem that Td and p of Bi0.5Na0.5TiO3-based ceramics cannot be increased simultaneously has not been solved. In this work, (1-x)Bi0.5Na0.5TiO3-xBaNi0.5Nb0.5O3 (BNT-xBNN, x = 0, 0.02, 0.03, 0.04 mol) lead-free ceramics were prepared by conventional solid-state reaction method. Introduction of BaNi0.5Nb0.5O3 can facilitate lattice cell expansion and decrease of the O-B-O bond angles, providing more possibilities for the B-site ion to deviate from the equilibrium position, producing micrometer level grain size (3.25–6.15 µm) with good ferroelectric performance (Pr = 42 μC/cm2, Ps = 47 μC/cm2). The permittivity (εr) of pristine samples raises from 439 to 723 when the content of BNN ascends to 0.03 mol. Hence, an enhanced room temperature p of 7.91 × 10−4 C m−2 K−1 with a high Td of about 150 °C has been attained in BNT-xBNN with x = 0.03 mol, which concomitantly generates the energy density of 22.3 μJ/cm3 with 90 MΩ load. Our work contributes to the development of pyroelectric properties for practical applications in energy harvesting.

Graphene Aerogel‐Supported Phase‐Change Material for Pyroelectric Energy Harvesting: Structural Modification and Form Stability Analysis

3D porous graphene aerogel (GA) has a capability to infiltrate plenty of phase‐change materials (PCM) into the internal pore. Since carbon‐based materials can offer excellent solar light absorption and conversion of thermal energy, they are widely used as container‐like supporting materials. In general, the GA shows a volume shrinkage problem due to the capillary force during the infiltration process, thus causing a loss in pore volume, that is, PCM weight loss. The PCM amount is proportional to both the absorbed and released thermal energies. Herein, cysteamine is introduced to bind GA. The PCM composite can reduce the volume shrinkage and have an excellent form stability even under the external force. Two kinds of PCMs are connected to a pyroelectric electrode to generate electrical energy. In addition, finite‐element method estimates the temperature profile and electrical peaks to confirm experimental results.

Enhancement of a Pyroelectric Body Energy Harvesting Scheme Employing Pulsed Electric Fields

Enhancement of a Pyroelectric Body Energy Harvesting Scheme Employing Pulsed Electric Fields

Modeling of Olsen cycle for pyroelectric energy harvesting and assessment of abnormal electrocaloric effect in ferroelectric single crystals

The energy conversion potential of ferroelectric materials originating from their phase transitions, in particular temperature ranges and electric field values, is very promising. Pyroelectric energy harvesting consists of directly converting thermal energy into electrical energy. Due to its high energy conversion potential, the Olsen cycle is the most favorable for pyroelectric energy harvesting. This cycle includes two isothermal and two constant electric field branches. In this study, the Olsen cycle was modeled, then varying temperatures and applied electric field directions for different crystal orientations were simulated. Polarization responses were obtained via the Landau–Devonshire theory. Then, an innovative way to model the electrocaloric effect was proposed; experimental results and first-principle calculations confirmed the simulation results. The resulting negative electrocaloric effect due to crystal orientation, previously reported in the literature, has been successfully simulated through a phenomenological approach. Finally, we identified which phase transitions are interesting for pyroelectric energy harvesting applications depending on crystal orientations while obtaining an energy density in the order of ≈102mJ/cm3. This value corresponds to previous results in the literature.

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 thermoelectrics1, photovoltaics2 and thermophotovoltaics3. Pyroelectric materials, converting temperature periodic variations in electricity, have been considered as sensors4 and energy harvesters5–7, although we lack materials and devices able to harvest in the joule range. Here we develop a macroscopic thermal energy harvester made of 42 g of lead scandium tantalate in the form of multilayer capacitors that produces 11.2 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.

Harvesting of residuary thermal energy from Mg modified BNT-BKT pyroelectric solid solution using Olsen cycle

The incessant necessity of self-powered applications such as bio-medical devices, a wireless sensor etc has driven the request for high-production lead free pyroelectric materials towards energy harvesting. Herein, magnesium substituted bismuth sodium potassium titanate pyroelectric systems (Bi0.50Na0.41K0.09)(Ti1-xMgx)O3 where x = 0, 0.01 and 0.02 was synthesized. An indispensable role of magnesium on structural, microstructural and dielectric properties has been investigated. The co-existence of rhombohedral and tetragonal phase is confirmed by the X-ray diffraction pattern. The ferroelectric to relaxor/antiferro-electric phase transition was observed to be decrease from 150 °C to 76 °C with increase in doping from 0% to 2% respectively. Thereafter, the Olsen cycle was performed on the ferroelectric loops to demonstrate the energy harvesting properties of fabricated materials. The maximum of 475 mJ cm−1, 479 mJ cm−1 and 588 mJ cm−1 heat energy has been harvested from x = 0, 0.01 and 0.02 samples respectively. The Present work un-plug the various opportunities to develop high-performance pyroelectric energy harvester by utilizing lead free materials.

Gravure Printing for PVDF Thin-Film Pyroelectric Device Manufacture

Pyroelectric energy harvesting is one of the more recent and promising solid-state approaches for directly converting time-dependent temperature fluctuations into electric energy. Conventional printing technologies can offer many advantages for the production of pyroelectric thin-film-based devices, such as low cost, low temperature, the use of flexible substrates and shaping at the same time as deposition. Nevertheless, some issues related to low printed thickness and film-forming microstructure control need to be addressed. In this exploratory study, the possibility of exploiting the highly attractive gravure printing process for the potential industrial manufacture of flexible polyvinylidene fluoride (PVDF) thin-film pyroelectric devices was investigated. By the use of corona pre-treatment of the printing substrate and low-temperature polar solvent evaporation, multilayer gravure-printed PVDF pyroelectric devices were successfully manufactured for the first time, achieving a maximum generated current of 0.1 nA at 2.5 K/s from a device with an active area of 1 cm2. Considering the very low thermal inertia and performance scaling by the area expected for pyroelectric thin-film-based devices, combined with the upscaling potential of roll-to-roll gravure printing, our results provide new opportunities for on-demand, low-cost pyroelectric device manufacture and their integration in hybrid harvesters.

High Open-Circuit Voltage of a Pyroelectric Energy Harvester Based on KNN Single Crystals

High Open-Circuit Voltage of a Pyroelectric Energy Harvester Based on KNN Single Crystals