Design and 3D Printing of Optimized Electrodes for Supercapacitor Applications

Supercapacitors have attracted considerable attention within the automotive, aerospace, and telecommunication industries due to their fast charging/discharging ability. The high electrical conductivity and surface area of porous carbons make them attractive candidates for supercapacitor electrodes. Maximizing porous carbon in electrodes (I.e., thick electrodes) is one strategy to further increase energy density of these devices. However, these porous carbons suffer from sluggish charged species transport in thicker electrodes, which limits them to thin electrode designs. In this work, we investigate the use of computer-guided optimization and additive manufacturing to design and print thick porous electrodes with improved performance. Electrodes with optimal performance were designed by topology optimization and printed by projection micro stereolithography (PµSL) using PR48 resin. The PR48 resin was then pyrolyzed (PR48-P) to create the final conductive electrode. The PR48-P electrodes with optimized design exhibited improved capacitance compared to those control electrodes printed as cubic lattice structures. To further improve performance, a new resin was synthesized by combining graphene oxide (GO) and trimethylolpropane triacrylate (TMPTA). Electrodes printed with 3 wt% GO in TMPTA exhibited improved capacitance retention after pyrolysis compared to PR48-P electrodes. This work demonstrates the benefits of using topology optimization to design electrodes and material development to improve functional properties of 3D printable resins. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.