Rheological and structural characterization of 3D-printable polymer electrolyte inks

Abstract

Direct ink writing (DIW) is an extrusion-based technique that is increasingly used for extrusion of gel and quasi-solid polymer electrolytes for energy-based devices. Due to their high tunability in viscoelastic properties, poly(ethylene oxide) (PEO)-based inks are prime candidates as functional substrate material for optimization-based studies to improve extrudate printability. While optimization of ink printability in conventional 2D printing applications has been previously described, we have yet to observe a report analyzing the relationship between the morphological and rheological properties of direct-ink-writable inks tailored for printed energy devices (e.g., dye-sensitized solar cells (DSSCs)). To address this gap, we have characterized various electrolyte inks' morphological, rheological, and structural properties and studied these relationships to modify the ink's flow characteristics during extrusion and structure after deposition with high specificity. These metrics are used to define the electrolyte ink's printability as a step towards realization of printable electrolyte inks for DSSC devices.

Keywords

• Direct ink writing
• Polymer electrolyte
• poly(ethylene oxide)
• Dye-sensitized solar cell
• Rheology