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Fabrication route of PZT and KNN piezoelectric materials. Please note that for simplicity we are quoting typical laboratory-based times and temperatures for comparison but it is anticipated that these may be modified slightly for commercial production for different manufacturers.
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The increasing awareness of the environmental and health threats of lead as well as environmental legislation, both in the EU and around the world targeted at decreasing the use of hazardous substances in electrical appliances and products has reinvigorated the race to develop lead-free alternatives to lead zirconate titanate (PZT), which presently...
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... ceramics is typically fabricated using conventional powder processing technology which entails the four basic steps: i) preparation of powder; ii) shape forming; iii) sintering at high temperature and iv) component finishing. 54 As shown in Figure 1 (R.H.S), the starting materials for PZT are lead oxide (PbO), titanium oxide (TiO 2 ) and zirconium dioxide (ZrO 2 ). ...
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... manufacturing route for KNN-based compositions (Figure 1 can lead to the formation of secondary phases which impair the piezoelectric performance. ...
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... Eco-indicator 99 results for PZT in terms of damage to the ecosystem, human health and resources are shown in Figure 10. As indicated, the highest impact from the PZT production comes from waste disposal of lead which constitutes a threat to human as well as aquatic species. ...
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... and drying operations constitute 35% and 22% respectively. Electrical energy distribution is shown in Figure 11c. Optimised sintering approaches such as the use of sintering aids and low temperature processing technology can therefore contribute to the overall reduction in thermal energy demand for KNN and for that matter PZT fabrication. ...
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... Total primary energy consumption including thermal and electrical energy and materials embedded all expressed in MJ/kg. Figures 11 (b), (c) and (d) indicate the percentage contributions of each process or material relative to Figure 11 (a). ...
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... Total primary energy consumption including thermal and electrical energy and materials embedded all expressed in MJ/kg. Figures 11 (b), (c) and (d) indicate the percentage contributions of each process or material relative to Figure 11 (a). ...
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... results, in terms of actual values, of how process-based results compared to EIO results are shown in Table 2 and represented in graphical form in Figure 12 based on percentage contributions. Figure 14 shows the environmental profile of all the unit process exchanges representing the process analysis data of 1kg of KNN fabricated in the laboratory. ...
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... results, in terms of actual values, of how process-based results compared to EIO results are shown in Table 2 and represented in graphical form in Figure 12 based on percentage contributions. Figure 14 shows the environmental profile of all the unit process exchanges representing the process analysis data of 1kg of KNN fabricated in the laboratory. All the thirteen sustainability metrics are normalised, ensuring that the absolute indicator of each category of impact is 100%. ...
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... the thirteen sustainability metrics are normalised, ensuring that the absolute indicator of each category of impact is 100%. As indicated in Figure 14, the use of niobium pentoxide is the singular most outweighing contributor to climate change (76%), acidification (86%) eutrophication (89%), land use (97%) fresh water aquatic ecotoxicity (85%), fresh water sediment ecotoxicity (85%), human toxicity (93%), marine aquatic ecotoxicity (79%), marine sediment ecotoxicity (79%), terrestrial ecotoxicity (82%), ionising radiation (72%), malodours air (93%). Niobium pentoxide also has influence on material utilisation (52%), with thermal and electrical energy demand contributing 29% and 19% respectively. ...
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... is to be noted that the electrical energy required to produce 1kg of KNN (82.21 kWh) surpasses that of PZT (79.21 kWh). However, as indicated in Figure 14, the environmental impact of KNN is dominated by the presence of niobium due to its high emissions intensity compared to electricity, across all indicators. Freshwater sediment ecotoxicity (FSETP 100a) ...
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... this section, consideration is given to the impact of IO indirect (upstream) emissions in the production of KNN across six sustainability indicators with respect to vital economic sectors as indicated in Figure 15. ...
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... Eco-indicator 99 results for KNN based on damages to ecosystem, human health and resources is shown in Figure 16. As indicated, the highest impact from KNN production comes from the raw material extraction of niobium with a negligibly small impact from the waste disposal process. ...
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... quality Finally, as shown in Figure 18 (d), KNN causes more upstream IO GHG than PZT across all the economic sectors shown with the most significant upstream emissions coming from the chemical sector for both materials. What underlies the differences in this result between the two compounds are the material cost, substitution cost and energy (i.e. ...
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The prohibition of lead in many electronic components and devices due to its toxicity has reinvigorated the race to develop substitutes for lead zirconate titanate (PZT) based mainly on the potassium sodium niobate (KNN) and sodium bismuth titanate (NBT). However, before successful transition from laboratory to market, critical environmental assess...
Citations
... Traditional piezoelectric ceramics, such as lead zirconium titanate (PZT), exhibit high piezoelectric coefficients but suffer from environmental concerns and high production costs. Indeed, some works established PZT life cycle assessment at around 55.74 kg equivalent CO 2 for 1 kg of PZT [6]. This value of global warming potential (GWP) is divided as 46.67 kg equivalent CO 2 for the production and 9.08 kg equivalent CO 2 for the economical part (transportation, selling, etc.). ...
Piezoelectric polymers, such as poly(vinylidene fluoride) (PVDF), offer a sustainable alternative to traditional ceramic‐based energy harvesters, addressing concerns regarding environmental impact and resource scarcity. The energy harvesting ability of these PVDFs under various mechanical constraints has been widely investigated. To determine the power output of the material, most of the studies usually use the same electrical setup: the piezoelectric material is in series with a load resistor and the voltage is measured at the resistor's terminals. This usual “passive” method of measurement can underestimate the optimal value of energy harvesting ability. To accurately assess the energy harvesting potential of PVDF, a novel “active” measurement method is proposed. This method involves the simultaneous application of both mechanical and electrical stimuli to the PVDF film, enabling precise control and optimization of the energy harvesting process. To validate this approach, the structural and electrical properties of the stretched PVDF were initially characterized to produce a datasheet. Subsequently, the energy harvesting performance was investigated using both “passive” and “active” methods. The results demonstrated a significant enhancement in power output, with the “active” method yielding up to 3.2 times higher values compared with the “passive” method. This finding highlights the importance of employing advanced measurement techniques to accurately characterize the energy harvesting capabilities of piezoelectric materials.
... PZT contains toxic lead and the toxicity issue is further enhanced due to the enhanced volatility, particularly during the calcination or sintering process. Thus, LFPPs have been commercialized and their development has been promoted by targeting problems like low durability and d 33 [14]. ...
Chapter 18:
Piezoelectric materials possess unique ability to interconvert electrical and mechanical energy, enabling their application in a variety of important areas like harvesting energy, high-power applications, sensing and actuation, and more. In this regard, lead titanate and other lead-based perovskites have been
commercialized due to their compelling dielectric and ferroelectric properties. However, growing environmental concerns regarding lead exposure during the synthesis and integration of lead-based materials in high-performance applications led to the enforcement of restrictive laws and regulations. A major part of the ongoing research in this field is more or less influenced by the desire to develop lead-free substitutes that have either comparable or, in some cases, better piezoelectric properties. As a potential substitute, perovskite ceramics have gained considerable interest because of their characteristic feature to respond to applied electrical fields as well as for the ease of tuning properties simply by making any compositional change. This chapter delves into the latest developments in lead-free piezoelectric perovskites (LFPP), providing a thorough overview of the crystallographic structures, polarization mechanisms, and material properties of BaTiO3, BiFeO3, Bi0.5Na0.5TiO3, and (K, Na) NbO3, which all contribute to their piezoelectric behavior. Finally, current challenges and prospects associated with LFPPs based on their performance have been discussed.
... Could the multi-century career of the Rochelle salt invention continue? Actual piezoelectric materials are hard and difficult to produce in non-standard shapes in a ecological or eco-designed paradigm [16]. Rochelle salt crystal (RS) is a crystalline solid with expected piezoelectric and ferroelectric properties, which can be easily obtained at relatively low temperatures. ...
This paper details some characterization results of selected Rochelle salt based transducers previously or recently fabricated using various techniques. Several elements of the expected increasing lifetime are shown. Polarization results comparing monocrystalline and polycrystalline structures show that the former is ferroelectric and strongly piezoelectric as expected. The second behaves as a piezoelectric and is strongly electrostrictive, reaching a significant displacement when subjected to high voltage. Because Rochelle salt could be the lowest environmental footprint ferroelectric and piezoelectric, it is an ecological smart material. It may have some limitations, but also circular and recoverable highly interesting properties. Thus, the possibility of revisiting the Rochelle salt based technology for disposable, ecological or eco-designed efficient acoustic transducer is here illustrated and discussed.
... The application of LCA in environmental policy is expanding to encompass intricate and extensive externalities 40 . It is a recognized systematic method employed to identify, quantify, and evaluate the environmental impacts associated with the entire value chain of an activity, product, or process 41,42 . The fundamental concept of LCA involves tracing a product throughout its life stages and establishing a distinction between its product system and the external environment 43 . ...
This research investigates the environmental sustainability of three integrated power cycles: combined geothermal-wind, combined solar-geothermal, and combined solar-wind. Here, a promising solar technology, the perovskite solar cell, is considered and analysed in conjunction with another renewable-based cycle, evaluating 17 scenarios focusing on improving the efficiency and lifespan. Among the base cases, combined solar-wind had the lowest ozone depletion impact, while combined geothermal-wind had the lowest freshwater ecotoxicity and marine ecotoxicity impacts. The study shows that extending the perovskite solar cell lifespan from 3 to 15 years reduces CO2 emissions by 28% for the combined solar-geothermal and 56% for the combined solar-wind scenario. The most sustainable cases in ozone depletion, marine ecotoxicity, freshwater ecotoxicity, and climate change impacts are combined solar-wind, combined solar-geothermal, and combined geothermal-wind, respectively, among all evaluated scenarios. This research suggests investing in the best mix of integrated power cycles using established and emerging renewable technologies for maximum environmental sustainability.
... 4 Considering the pollution of lead-based materials in the process of preparation and scrapping to the sustainable development of society, countries and regions are successively issuing laws to restrict the use of lead-based materials in products. 5,6 As a result, many efforts have been made to explore the environmentally friendly high-performance lead-free materials to substitute these lead-based piezoelectric ceramics. Among them, K 0.5 Na 0.5 NbO 3 -based (KNN-based) ceramics have attracted large attention due to their high Curie temperature and excellent piezoelectric properties. ...
Considering that lead‐based piezoelectric ceramics are not conducive to sustainable development, the research and preparation of environmentally friendly lead‐free piezoelectric ceramics has become a new trend. Among them, potassium‐sodium niobate based (KNN‐based) piezoelectric ceramics are considered as the most potential candidates because of their good piezoelectric properties. However, the strong sensitivity to temperature has hindered the further application of KNN‐based ceramics. In this work, the ZnO dopant was introduced in 0.96K0.48Na0.52Nb0.96Sb0.04O3–0.04Bi0.5Na0.5HfO3 ceramics to improve their piezoelectric characteristics. On the one hand, Zn²⁺ could occupy B‐site and thus enhance the lattice distortion of BO6 octahedra, resulting the enhanced piezoelectric properties including kp = 46%, d33 = 344 pC/N and TC = 282°C in the optimal component with x = 0.01. On the other hand, the defect dipole formed by the acceptor dopant Zn²⁺ pinned the motion of domain wall, and thus improved the temperature stability over a wide temperature range of 20°C to 180°C, where the descent in unipolar strain decreased from 35% (x = 0) to 23% (x = 0.01). This work provides a point of view about how ZnO dopants make an influence on the KNN‐based ceramics.
... Life Cycle Assessment (LCA) analysis provides another point of view to the comparison of lead-based and lead-free piezoelectric ceramics. It was reported that the extraction of niobium from niobium ore and its purification represents a substantial environmental impact, implying that KNN can not be considered a 'greener' alternative to PZT [55,56]. A recent LCA study acknowledged the problem of niobium mining but concluded that the overall ecologically sustainable impact of KNN was much less than that related to PZT [57]. ...
Sodium potassium niobate (KNN) and KNN-based ceramics are considered viable alternatives to lead-based piezoelectric ceramics. Their chemical composition is the key to their phase transitional behaviour, which determines their functional properties. On the other hand, the microstructure is another factor that crucially contributes to shaping the properties of ceramics. The review addresses the synthesis of the perovskite solid solution as well as the issue of chemical homogeneity depending on the choice of the reagents. In sintering, the importance of stoichiometry in densification and microstructure evolution is discussed. Phase boundary engineering, which has been effective in tailoring the functional response of KNN-based ceramics, is discussed from the viewpoint of material chemistry and processing that may contribute to chemical homogeneity. Finally, consolidation approaches with a lower thermal budget are addressed.
... This combination of techniques results a consistent approach but one where complex data management is required (Islam et al., 2016). This technique has been well used in a wide range of industrial sectors and contexts (Ibn-Mohammed et al., 2016;Bilec et al., 2006;Smith et al., 2019). There are four generally utilised HLCA techniques, namely tiered, integrated, path exchange, and matrix augmentation (Crawford et al., 2018). ...
... The PZT material in the generator is a relatively large component of the device, but there exists only one peer-reviewed LCA that has measured the environmental impacts of PZT, 13 and there is no life cycle inventory in known databases for this component. Most uses of PZT are in small quantities in low-power applications such as in medical test devices and monitoring systems as sensors, or in advanced active control systems as actuators, for which LCAs that include detailed information on the piezoelectric element have not previously been published. ...
... There is a substantial difference between the results of this study and the impacts of the Ibn-Mohammad et al. (2016) study, 13 which reported 55.74 kg CO 2eq /kg for the climate change impact and 0.23 kg SO 2eq /kg for acidification potential for piezoelectric material, nearly 5 and 2.5 times as high, respectively, as these LCA results. In their study, the highest impacts across multiple impact categories originate from electricity use at about 90%, 13 which is inconsistent with producing a substance from the ceramic family. The highest impacts calculated among the three chemical compositions of the PZT material were 0.0917 kg SO 2eq /kg for acidification potential, 2.40 3 10 À6 CTUh/kg for carcinogenic potential, and 3,503 CTUe/kg for the ecotoxicity potential ( Figure 3). ...
Piezoelectric energy harvesting devices (PEHDs) for road installation are being researched as potentially low-emission electrical generators, but their life cycle greenhouse gas (GHG) emissions must be assessed to guide their design and implementation toward minimizing their carbon footprint. Parametric life cycle assessments (LCAs) of a PEHD, its generator, and the piezoelectric material were performed using data from a pilot-scale PEHD installation. The GHG emissions of the lead zirconate titanate (PZT) piezoelectric stack were determined to be lower than previously reported in the literature at 10.81–15.90 kg CO2eq/kg piezoelectric. The GHG emissions of electricity generated by a PEHD range from 48.65–588.63 g CO2eq/kWh, spanning from similar to renewables to slightly higher than electricity from natural gas. Sensitivity analysis indicated that spatial parameters and the device lifetime had the largest influence on the LCA results. PEHDs installed on roads show potential to be low-GHG emission energy systems.
... The nanodomains/PNRs, which range in size from several nm to µm and are more responsive to external electric fields, are predicted to facilitate a moderate P and slight Pr in RFEs, and these features are expected to contribute to a high Wrec and η [68]. In this regard, various lead-based and lead-free perovskite RFEs, namely (Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) [69,70], Pb(Mg1/3Nb2/3) O3-PbTiO3 (PMN-PT) [70], (Pb, La)(Zr, Ti)O3 (PLZT) [71] and BT [72][73][74], (Na, K)NbO3 (KNN) [75,76], and (Bi, Na)TiO3 (BNT) [75,76], have been explored for energy storage applications, respectively. ...
... The nanodomains/PNRs, which range in size from several nm to µm and are more responsive to external electric fields, are predicted to facilitate a moderate P and slight Pr in RFEs, and these features are expected to contribute to a high Wrec and η [68]. In this regard, various lead-based and lead-free perovskite RFEs, namely (Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) [69,70], Pb(Mg1/3Nb2/3) O3-PbTiO3 (PMN-PT) [70], (Pb, La)(Zr, Ti)O3 (PLZT) [71] and BT [72][73][74], (Na, K)NbO3 (KNN) [75,76], and (Bi, Na)TiO3 (BNT) [75,76], have been explored for energy storage applications, respectively. ...
... The nanodomains/PNRs, which range in size from several nm to µm and are more responsive to external electric fields, are predicted to facilitate a moderate P and slight P r in RFEs, and these features are expected to contribute to a high W rec and η [68]. In this regard, various lead-based and lead-free perovskite RFEs, namely (Pb(Zn 1/3 Nb 2/3 )O 3 -PbTiO 3 (PZN-PT) [69,70], Pb(Mg 1/3 Nb 2/3 ) O 3 -PbTiO 3 (PMN-PT) [70], (Pb, La)(Zr, Ti)O 3 (PLZT) [71] and BT [72][73][74], (Na, K)NbO 3 (KNN) [75,76], and (Bi, Na)TiO 3 (BNT) [75,76], have been explored for energy storage applications, respectively. ...
Materials offering high energy density are currently desired to meet the increasing demand for energy storage applications, such as pulsed power devices, electric vehicles, high-frequency inverters, and so on. Particularly, ceramic-based dielectric materials have received significant attention for energy storage capacitor applications due to their outstanding properties of high power density, fast charge–discharge capabilities, and excellent temperature stability relative to batteries, electrochemical capacitors, and dielectric polymers. In this paper, we present fundamental concepts for energy storage in dielectrics, key parameters, and influence factors to enhance the energy storage performance, and we also summarize the recent progress of dielectrics, such as bulk ceramics (linear dielectrics, ferroelectrics, relaxor ferroelectrics, and anti-ferroelectrics), ceramic films, and multilayer ceramic capacitors. In addition, various strategies, such as chemical modification, grain refinement/microstructure, defect engineering, phase, local structure, domain evolution, layer thickness, stability, and electrical homogeneity, are focused on the structure–property relationship on the multiscale, which has been thoroughly addressed. Moreover, this review addresses the challenges and opportunities for future dielectric materials in energy storage capacitor applications. Overall, this review provides readers with a deeper understanding of the chemical composition, physical properties, and energy storage performance in this field of energy storage ceramic materials.
... Research on lead-free electroceramics has increased due to concerns about lead toxicity [2][3][4]. Efforts are being made to improve their storage capacity to replace lead-based materials. Currently, several lead-free ceramic systems are considered potential candidates for energy storage applications [5]. ...
