Speaker
Description
The growing concerns on environmental impact require a new generation of materials and processes for sustainable electronics and energy storage systems [1]. In this scope, additive manufacturing techniques arise as an effective process to improve the sustainability of device fabrication [2]. In this work, direct-ink-writing was used to produce poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) films and membranes. Different parameters were variated such as solvent evaporation temperature and fill density percentage, which allowed to obtain different morphologies, including dense films and porous membranes. In addition, the different conditions allowed to tune electroactive 𝜷-phase content, thermal and mechanical properties. The prepared PVDF-HFP films with a fill density of 80 and a solvent evaporation temperature of 50 °C, show a dielectric constant of 16 at 1 kHz and a piezoelectric d33 coefficient of 4 pC.N-1. The porous structured samples were applied as separators for lithium-ion batteries. The highest ionic conductivity (3.8 mS.cm-1) is achieved for the sample with a fill density of 100 and a solvent evaporation temperature of 25 ºC. The assembled batteries present excellent cycling performance, achieving values up to 130 mAh.g-1 at C/8 rate. With this work, the versatility of the printing process is demonstrated, allowing the fabrication of advanced materials for high-end applications.
