Improved Li and Sb doped lead-free (Na,K)NbO3 piezoelectric ceramics for energy harvesting applications

2018 ◽  
Vol 44 (18) ◽  
pp. 22219-22224 ◽  
Author(s):  
Jinhwan Kim ◽  
Jae-Hoon Ji ◽  
Dong-Jin Shin ◽  
Jung-Hyuk Koh
Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3725 ◽  
Author(s):  
Manuel Vázquez-Rodríguez ◽  
Francisco J. Jiménez ◽  
Lorena Pardo ◽  
Pilar Ochoa ◽  
Amador M. González ◽  
...  

In this paper, a new prospect using lead-free piezoelectric ceramics is presented in order to determine their behavior in piezoelectric-based road traffic energy harvesting applications. This paper will describe the low-cost and fully programmable novel test bench developed. The test bench includes a traffic simulator and acquires the electrical signals of the piezoelectric materials and the energy harvested when stress is produced by analogous mechanical stimuli to road traffic effects. This new computer-controlled laboratory instrument is able to obtain the active electrical model of the piezoelectric materials and the generalized linear equivalent electrical model of the energy storage and harvesting circuits in an accurate and automatized empirical process. The models are originals and predict the extracted maximum power. The methodology presented allows the use of only two load resistor values to empirically verify the value of the output impedance of the harvester previously determined by simulations. This parameter is unknown a priori and is very relevant for optimizing the energy harvesting process based on maximum power point algorithms. The relative error achieved between the theoretical analysis by applying the models and the practical tests with real harvesting systems is under 3%. The environmental concerns are explored, highlighting the main differences between lead-containing (lead zirconate titanate, PZT) and lead-free commercial piezoelectric ceramics in road traffic energy harvesting applications.


2021 ◽  
Author(s):  
Javier Eduardo Camargo ◽  
Santiago Osinaga ◽  
Mariano Febbo ◽  
Sebastián P. Machado ◽  
Fernando Rubio-Marcos ◽  
...  

Abstract The development of bulk piezoelectric ceramics with high energy conversion efficiency is of decisive importance for the requirements of the advanced energy harvesting devices toward miniaturization and integration. There is an additional motivation in the piezoelectric ceramics, lead titanate-zirconate (PZT) ceramics are the most widely used energy harvesting (EH) materials. This fact is important because legal restrictions on the use of lead in electronic devices have led to greater efforts being made to develop lead-free alternatives to PZT-based materials. Here, we propose the Bi0.5(Na0.8K0.2)0.5TiO3 (BNKT) lead-free piezoceramics as a good candidate for the replacement of toxic lead compounds for energy harvesting applications. For that, we have carried out a systematic study of the voltage generation of BNKT-based piezoceramics for (EH) purposes. Specifically, our results reveal that the BNKT–based lead-free piezoceramics show adequated effective capacitance and output energy due to more effective performance with a piezoelectric charge coefficient and a maximum generated output voltage as high as 12.8 pC/N and 19.9 V, respectively. Finally, we consider that the design of new lead-free piezoceramics with superior property coefficients and functionalities, such as the BNKT-based piezoceramics, should be seriously considered as candidates for the replacement of the current toxic lead-based compounds.


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