3D Printing Temperature Tailors Electrical and Electrochemical Properties through Changing Inner Distribution of Graphite/Polymer

Abstract

The rise of 3D printing technology, with fused deposition modeling as one of the simplest and most widely used techniques, has empowered an increasing interest for composite filaments, providing additional functionality to 3D‐printed components. For future applications, like electrochemical energy storage, energy conversion, and sensing, the tuning of the electrochemical properties of the filament and its characterization is of eminent importance to improve the performance of 3D‐printed devices. In this work, customized conductive graphite/poly(lactic acid) filament with a percentage of graphite filler close to the conductivity percolation limit is fabricated and 3D‐printed into electrochemical devices. Detailed scanning electrochemical microscopy investigations demonstrate that 3D‐printing temperature has a dramatic effect on the conductivity and electrochemical performance due to a changed conducive filler/polymer distribution. This may allow, e.g., 3D printing of active/inactive parts of the same structure from the same filament when changing the 3D printing nozzle temperature. These tailored properties can have profound influence on the application of these 3D‐printed composites, which can lead to a dramatically different functionality of the final electrical, electrochemical, and energy storage device.

Photo-Responsive Doped 3D-Printed Copper Electrodes for Water Splitting: Refractory One-Pot Doping Dramatically Enhances the Performance

“…SPECM is a scanning probe technique for the non-invasive examination of chemical, electrochemical, and photoelectrochemical characteristics with high spatial resolution. , The microscopic image is generated by recording an amperometric current at the SPECM probe, typically a disc-shaped UME dependent on the position . The localization of conductive surfaces on the 3DCu sample was done using the so-called “feedback mode.” In the feedback mode, the oxidation current of the redox-active mediator FcMeOH measured at the UME depends on the conductivity of the sample and the tip-to-substrate distance. , Isolating materials impede the diffusion of the mediator to the UME, resulting in a decreased current, called “negative feedback”. Conductive materials enable the recycling of the mediator, which results in a higher current, indicating positive feedback.…”

“…The localized (photo)­electrochemical characterization using SPECM was done with a cross-section sample of a 3DCu electrode doped with Al 2 O 3 . The detailed procedure for preparing the cross-section samples is published elsewhere . Briefly, the 3DCu electrode was encapsulated in a two-component epoxy resin using a vacuum impregnation chamber (CITOVAC, Struers Aps).…”

“…The detailed procedure for preparing the cross-section samples is published elsewhere. 30 Briefly, the 3DCu electrode was encapsulated in a twocomponent epoxy resin using a vacuum impregnation chamber (CITOVAC, Struers Aps). The resin was cured overnight at room temperature, and mechanical grinding/polishing was performed using a grinder/polishing machine (TEGRAMIN 30, Struers Aps) with a series of SiC grinding foils (final grit size 4000) and diamond suspension polishing fluids (DP-Suspension P with 9 and 3 μm).…”

The Effects of Material Extrusion Printing Speed on the Electrochemical Activity of Carbon Black/Polylactic Acid Electrodes**

“…[14][15][16][17] However, manufacturing composite electrodes using material extrusion process also provides different variables which can influence the conductivity of the printed electrode. [18,19] Printing parameters can have an influence on the structure of the electrode and previous studies have shown that orientation and print layer thickness can have a significant influence on the number of conductive pathways present within the printed conductive electrode. [20,21] Given the importance of manufacturing electrodes with optimal conductivity through material extrusion process, understanding the influence of different parameters on the printed part is critical as this can alter the conductivity of the electrode.…”

“…However, manufacturing composite electrodes using material extrusion process also provides different variables which can influence the conductivity of the printed electrode [18,19] . Printing parameters can have an influence on the structure of the electrode and previous studies have shown that orientation and print layer thickness can have a significant influence on the number of conductive pathways present within the printed conductive electrode [20,21] .…”