ja7b06173_si_001.pdf (2.04 MB)
Patternable Solvent-Processed Thermoplastic Graphite Electrodes
journal contribution
posted on 2017-08-10, 00:00 authored by Kevin
J. Klunder, Zach Nilsson, Justin B. Sambur, Charles S. HenrySince
their invention in the 1950s, composite carbon electrodes
have been employed in a wide variety of applications, ranging from
batteries and fuel cells to chemical sensors, because they are easy
to make and pattern at millimeter scales. Despite their widespread
use, traditional carbon composite electrodes have substandard electrochemistry
relative to metallic and glassy carbon electrodes. As a result, there
is a critical need for new composite carbon electrodes that are highly
electrochemically active, have universal and easy fabrication into
complex geometries, are highly conductive, and are low cost. Herein,
a new solvent-based method is presented for making low-cost composite
graphite electrodes containing a thermoplastic binder. The electrodes,
which are termed thermoplastic electrodes (TPEs), are easy to fabricate
and pattern, give excellent electrochemical performance, and have
high conductivity (700 S m–1). The thermoplastic
binder enables the electrodes to be hot embossed, molded, templated,
and/or cut with a CO2 laser into a variety of intricate
patterns. Crucially, these electrodes show a marked improvement in
peak current, peak separation, and resistance to charge transfer over
traditional carbon electrodes. The impact of electrode composition,
surface treatment (sanding, polishing, plasma treatment), and graphite
source were found to significantly impact fabrication, patterning,
conductivity, and electrochemical performance. Under optimized conditions,
electrodes generated responses similar to more expensive and difficult
to fabricate graphene and highly oriented pyrolytic graphite electrodes.
The TPE electrode system reported here provides a new approach for
fabricating high performance carbon electrodes with utility in applications
ranging from sensing to batteries.