Direct‐Ink‐Writing of Electroactive Polymers for Sensing and Energy Storage Applications

Abstract

Considering the high levels of materials used in the fields of electronics and energy storage systems, it is increasingly necessary to take into consideration environmental impact. Thus, it is important to develop devices based on environmentally friendlier materials and/or processes, such as additive manufacturing techniques. In this work, poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) are prepared by direct-ink-writing (DIW) by varying solvent evaporation temperature and fill density percentage. Different morphologies for both polymers are obtained, including dense films and porous membranes, as well as different electroactive 𝜷-phase content, thermal and mechanical properties. The dielectric constant and piezoelectric d 33 coefficient for dense films reaches up to 16 at 1 kHz and 4 pC N −1 , respectively for PVDF-HFP with a fill density of 80 and a solvent evaporation temperature of 50 °C. Porous structures are developed for battery separator membranes in lithium-ion batteries, with a highest ionic conductivity value of 3.8 mS cm −1 for the PVDF-HFP sample prepared with a fill density of 100 and a solvent evaporation temperature of 25 °C, the sample showing an excellent cycling performance. It is demonstrated that electroactive films and membranes can be prepared by direct-ink writing suitable for sensors/actuators and energy storage systems.

Smart and Multifunctional Materials Based on Electroactive Poly(vinylidene fluoride): Recent Advances and Opportunities in Sensors, Actuators, Energy, Environmental, and Biomedical Applications

“…The highest ionic conductivity value of 3.8 mS• cm −1 was obtained for poly(VDF-co-HFP) membrane prepared with a fill density of 100. 467 Due to its low degree of crystallinity, poly(VDF-co-TrFE) is ideal for separator membranes. For this polymer, membranes with surface pillar microstructures have been developed for battery separator applications, varying pillar diameter, height, and bulk thickness.…”

“…To develop devices based on environmentally friendlier processes, such as additive manufacturing techniques, PVDF, and poly­(VDF- co -HFP) membranes, have been prepared by DIW varying solvent evaporation temperature and fill density percentage. The highest ionic conductivity value of 3.8 mS·cm –1 was obtained for poly­(VDF- co -HFP) membrane prepared with a fill density of 100 …”

Last developments in polymers for wearable energy storage devices

“…In addition, this material could be a good option for wearable energy storage devices because of its flexibility. The same researchers' group 80 announced a strategy to print by LDM poly (vinylidene fluoride)‐co‐hexafluoropropylene (PVDF‐HFP) copolymer, trying different infill densities and evaporation temperatures. They obtained remarkable cycling stability with 100% of infill density which is desirable in binders.…”

Additive manufacturing of highly flexible impact wave propagation sensor

“…Polyvinylidene fluoride (PVDF) [16], lead zirconate titanate (PZT) [15], and barium titanate (BTO) are common piezoelectric materials for the fabrication of sensors. However, PVDF is not suitable for high-temperature environments, and PZT is toxic [17].…”