TY  - CONF
AU  - Vijatović Petrović, Mirjana
AU  - Craciun, Floriana
AU  - Cordero, Francesco
AU  - MERCADELLI, ELISA
AU  - Galassi, Carmen
AU  - Ilić, Nikola
AU  - Brunengo, Elisabetta
AU  - Despotovic, Zeljko V.
AU  - Bobić, Jelena
AU  - Džunuzović, Adis
AU  - Stagnaro, Paola
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2472
AB  - The important task of scientific community nowadays is finding the way to use enormous
amount of mechanical energy released everywhere around us as a renewable and safe energy
source.
This research was focused on the preparation of flexible composite films, by combining a
highly flexible polyvinylidene fluoride (PVDF) polymer matrix with lead-free piezoelectric
perovskites, 0.94[(Bi0.5Na0.5)TiO3]-0.06BaTiO3 (NBT-BT), in different ratios, using the hot
pressing method. A crucial point of this investigation is to show that this material is quite
versatile and possesses functional properties which are sensitive to both microscopic and
chemical modifications.
Detailed investigation of processed flexible films led to the main conclusion that
electrical properties of these composites can be affected by different factors. Firstly, the hotpressing
method itself induces the formation of electroactive β-phase of PVDF polymer, the
NBT-BT as filler with negatively charged surface enables a predominant formation of desirable
piezoelectric PVDF phase as well and additionally, there is an influence of concentration and
type (pre-preparation method) of the added filler.
Dielectric permittivity values of composites were up to 110 and highly depend on the
filler amount. A very useful zone around room temperature as a plateau with relatively constant
dielectric permittivity and losses was noticed in each film`s dielectric spectra. Anelastic
measurements have shown a complete agreement with dielectric properties in which the
temperature dependence of the Young’s modulus and the losses are dominated by those of the
polymer.
Regarding the resulting dielectric and ferroeletric properties of the flexible composites,
the potential of these materials for the energy storage application was investigated. Energy
density efficiencies obtained for investigated materials have shown a decreasing trend with
increasing amount of filler with values of 66-74 %.
Assembled energy harvesting units were made by proper wiring and covering the flexible
film with Kapton protection layer. The obtained output voltage while applying the impact force
was from 1 V to 7 V, depending on the type of the flexible film.
The main conclusion derived from this study is that composite flexible films made of
lead-free NBT-BT filler and PVDF, have high potential to be used for environmentally safe lowenergy
storage and energy harvesting devices.
PB  - IEEE ISAF-ISIF-PFM 2021, Sydney, Australia
C3  - IEEE ISAF-ISIF-PFM 2021, Sydney, Australia, May 16-21, 2021.
T1  - Composite flexible films prepared by hot pressing for low-energy harvesting and storage
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2472
ER  - 

@conference{
author = "Vijatović Petrović, Mirjana and Craciun, Floriana and Cordero, Francesco and MERCADELLI, ELISA and Galassi, Carmen and Ilić, Nikola and Brunengo, Elisabetta and Despotovic, Zeljko V. and Bobić, Jelena and Džunuzović, Adis and Stagnaro, Paola",
year = "2021",
abstract = "The important task of scientific community nowadays is finding the way to use enormous
amount of mechanical energy released everywhere around us as a renewable and safe energy
source.
This research was focused on the preparation of flexible composite films, by combining a
highly flexible polyvinylidene fluoride (PVDF) polymer matrix with lead-free piezoelectric
perovskites, 0.94[(Bi0.5Na0.5)TiO3]-0.06BaTiO3 (NBT-BT), in different ratios, using the hot
pressing method. A crucial point of this investigation is to show that this material is quite
versatile and possesses functional properties which are sensitive to both microscopic and
chemical modifications.
Detailed investigation of processed flexible films led to the main conclusion that
electrical properties of these composites can be affected by different factors. Firstly, the hotpressing
method itself induces the formation of electroactive β-phase of PVDF polymer, the
NBT-BT as filler with negatively charged surface enables a predominant formation of desirable
piezoelectric PVDF phase as well and additionally, there is an influence of concentration and
type (pre-preparation method) of the added filler.
Dielectric permittivity values of composites were up to 110 and highly depend on the
filler amount. A very useful zone around room temperature as a plateau with relatively constant
dielectric permittivity and losses was noticed in each film`s dielectric spectra. Anelastic
measurements have shown a complete agreement with dielectric properties in which the
temperature dependence of the Young’s modulus and the losses are dominated by those of the
polymer.
Regarding the resulting dielectric and ferroeletric properties of the flexible composites,
the potential of these materials for the energy storage application was investigated. Energy
density efficiencies obtained for investigated materials have shown a decreasing trend with
increasing amount of filler with values of 66-74 %.
Assembled energy harvesting units were made by proper wiring and covering the flexible
film with Kapton protection layer. The obtained output voltage while applying the impact force
was from 1 V to 7 V, depending on the type of the flexible film.
The main conclusion derived from this study is that composite flexible films made of
lead-free NBT-BT filler and PVDF, have high potential to be used for environmentally safe lowenergy
storage and energy harvesting devices.",
publisher = "IEEE ISAF-ISIF-PFM 2021, Sydney, Australia",
journal = "IEEE ISAF-ISIF-PFM 2021, Sydney, Australia, May 16-21, 2021.",
title = "Composite flexible films prepared by hot pressing for low-energy harvesting and storage",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2472"
}

Vijatović Petrović, M., Craciun, F., Cordero, F., MERCADELLI, E., Galassi, C., Ilić, N., Brunengo, E., Despotovic, Z. V., Bobić, J., Džunuzović, A.,& Stagnaro, P.. (2021). Composite flexible films prepared by hot pressing for low-energy harvesting and storage. in IEEE ISAF-ISIF-PFM 2021, Sydney, Australia, May 16-21, 2021.
IEEE ISAF-ISIF-PFM 2021, Sydney, Australia..
https://hdl.handle.net/21.15107/rcub_rimsi_2472

Vijatović Petrović M, Craciun F, Cordero F, MERCADELLI E, Galassi C, Ilić N, Brunengo E, Despotovic ZV, Bobić J, Džunuzović A, Stagnaro P. Composite flexible films prepared by hot pressing for low-energy harvesting and storage. in IEEE ISAF-ISIF-PFM 2021, Sydney, Australia, May 16-21, 2021.. 2021;.
https://hdl.handle.net/21.15107/rcub_rimsi_2472 .

Vijatović Petrović, Mirjana, Craciun, Floriana, Cordero, Francesco, MERCADELLI, ELISA, Galassi, Carmen, Ilić, Nikola, Brunengo, Elisabetta, Despotovic, Zeljko V., Bobić, Jelena, Džunuzović, Adis, Stagnaro, Paola, "Composite flexible films prepared by hot pressing for low-energy harvesting and storage" in IEEE ISAF-ISIF-PFM 2021, Sydney, Australia, May 16-21, 2021. (2021),
https://hdl.handle.net/21.15107/rcub_rimsi_2472 .