Piezoelectric and structural properties of bismuth sodium potassium titanate lead-free ceramics for energy harvesting

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 leadfree 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 leadfree 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.

A critical review: the impact of electrical poling on the longitudinal piezoelectric strain coefficient

“…Recently Camargo et al investigated the lead-free BNKT piezoceramic, and showed that higher piezoelectric properties ( d 33 = 129 pC N −1 and d 31 = 12.8 pC N −1 ) and an output voltage of 19.9 V g −1 were achieved, and that these materials can be successfully applied as energy harvesters instead of lead-based toxic materials. 186…”

“…Using the desired orientation of the domain ) and an output voltage of 19.9 V g À1 were achieved, and that these materials can be successfully applied as energy harvesters instead of lead-based toxic materials. 186 In BNT materials, texturing is achieved via the reactivetemplated grain increment process, using particles such as Na 0. NBiT or BiT particles into templates of pure-phase BNT.…”

“…Recently et al investigate on lead-free BNKT piezoceramic and shows higher piezoelectric properties and output voltage of d 33 129 pC/N, d 31 12.8 pC/N, and 19.9 V/g are achieved and can be successfully applied as energy harvesters instead of lead-based materials toxic[186].In BNT materials texturing is achieved by the reactive-templated grain increment process, using particles such as Na 0.5 Bi4.5 Ti 4 O 15 (NBiT) or Bi 4 Ti 3 O 12 (BiT). Current research has established ways for converting plate materials such as NBiT or illustrating BiT particles into templates of pure-phase BNT [187, 188].…”

Improvements in piezoelectric and energy harvesting properties with a slight change in depolarization temperature in modified BNKT ceramics by a simple technique

“…1 The development of piezoelectric materials with high energy conversion efficiency is of decisive importance for the requirements of advanced energy harvesting (EH) devices toward miniaturization and integration. 2 Lead titanate zirconate (PZT) ceramics are the most widely used energy harvesting materials due to their excellent piezoelectric properties, 3 i.e. , high mechanical quality factor ( Q m ), high piezoelectric constant ( d 33 ), and large planar electromechanical coupling factor ( k p ).…”

“…Recent reports have identified many possible lead-free candidates based on barium titanate (BaTiO 3 , BT), potassium sodium niobates (K 0.5 Na 0.5 NbO 3 , KNN), bismuth sodium titanates (Bi 0.5 Na 0.5 TiO 3 , BNT), bismuth potassium titanates (Bi 0.5 K 0.5 TiO 3 , BKT), and bismuth layered ferroelectrics. 2,5 Among them, BNT has been found to be a possible energy storage material due to its high spontaneous polarization ( P m ) exceeding 40 μC cm −2 , which results from the hybridization of the Bi 6p and O 2p orbitals. 6 Nevertheless, a pure BNT ceramic is known to be to be sintered with difficulty, and it also has other issues, such as beginning polarized with just as much complication, not to mention its having a high coercive field ( E c ), high conductivity, and poor temperature stability.…”