Design and Additive Manufacturing of Electrodes for Electrochemical Energy Storage

Supercapacitors exhibit rapid charge/discharge times and have attracted considerable attention within the automotive, aerospace, and telecommunication industries. The high electrical conductivity and surface area of porous carbons have been attractive for supercapacitor electrodes. Fabricating thick electrodes is one strategy to further increase energy density due to a higher volume fraction of active material. However, thick electrodes suffer from sluggish charged species transport. In this work, we investigate the use of computational optimization and additive manufacturing to design and fabricate thick porous electrodes with improved performance. Electrode performance was maximized by designing their morphologies via topology optimization and printing by projection micro stereolithography (PµSL) using commercial resin (PR48). The PR48 resin was then pyrolyzed (PR48-P) to create the final conductive electrode. The optimized PR48-P electrodes exhibited 99% improvement in capacitance compared to control electrodes printed with cubic lattice morphologies. To further improve performance, we formulated a resin combining graphene oxide (GO) and trimethylolpropane triacrylate (TMPTA). Electrodes printed with 3 wt% GO in TMPTA exhibited improved capacitance retention after pyrolysis compared to the PR48-P electrodes. This work demonstrates the enormous potential of leveraging topology optimization and additive manufacturing to resolve many challenges in the electrochemical storage and renewable energy regimes. 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 Figure 1