Graph Theory Design of 3D Printed Conductive Lattice Electrodes

Abstract

Abstract3D printing has the promising capability to fabricate engineered lattice structures with broadly tunable surface area and optimal geometries for maximizing structural and functional properties. This study characterizes the electrical conductivity of 3D lattices of varying size, structure, and porosity to guide additively manufactured electrode design in energy storage devices. Graph theory‐based calculations and experiments comparing the conductivity of multiple strut lattice structures and illustrating the scaling laws governing architectures with either coated or solid conductive struts are presented. The lightweight lattices explored here show higher conductivity than random foams that lack a periodic mesostructure. It is experimentally demonstrated that the 3D lattice type influences the specific capacity when employed in supercapacitors, outperforming 2D supercapacitor counterparts, and other 3D printed electrodes while allowing for optimization of the design for different energy storage applications. Additionally, it is shown that tuning the physical structure of the lattices allows for precise control over the electrical response to mechanical loading, as confirmed through experimental measurements. The lattice structure programs the electrodes’ mechanical stiffness, with higher relative density samples showing higher Young's modulus. These results can serve to guide the design of 3D printed electrodes in a variety of electrochemical and electromechanical device applications.

3D Printed Microlattices of Transition Metal/ Metal Oxides for Highly Stable and Efficient Water Splitting

“…The calculation of the surface area of microlattices follows a methodology similar to that outlined in our previous report (details available in the experimental methods section). [27] This validates that the 3D microlattices both expose a higher abundance of active sites and decreases interface resistance between the electrolyte and the electrode, thereby boosting electrocatalytic efficiency. We derived the Tafel plots from the polarization curves to delve into the reaction kinetics occurring on each electrode, shown in Figure 3b.…”

“…We use 3D architected polymer scaffolds as platforms for the subsequent in situ synthesis of transition metal and transition metal oxide interfaces on conductive graphitic carbon lattices, as depicted schematically in Figure 1c. Stereolithography is employed to create various 3D scaffold templates [27] with adjustable lattice structure, pore size, and volumetric porosity. After the printing phase, the 3D scaffold templates are immersed in an aqueous solution of a metal nitrate salt precursor, facilitating its infusion into the polymer -similar to the hydrogel additive manufacturing (HIAM) approach developed by Saccone, et al [26] .…”

“…Methods such as stereolithography (SLA), involve selectively solidifying a monomeric resin layer by layer, producing complex features down to the single micron scale for a variety of materials like ceramics [24,25] and hydrogels [26] . Additionally, SLA is adept at producing free-standing porous geometries such as microlattices that simultaneously provide high surface area and high electrical conductivity along with mechanical strength [27] . These properties make SLA promising for engineering masstransport in porous solids, but new chemistries and synthetic approaches are required for extending this benefit to transition metal/metal oxide catalyst materials.…”

“…In this paper, we present the fabrication and architectural design of 3D free-standing microlattices integrating highly active transition metal/metal oxides via SLA (stereolithography) [27] (shown in Figure 1a, b) for efficient electrocatalytic water splitting under alkaline conditions. This method utilizes polymer-based 3D scaffold templates designed explicitly for high gas evolution efficiency to improve electrode stability and enhance water splitting performance.…”

Rational Design of 3D‐Printed Metastructure‐Based Pressure Sensors

“…As described in previous work, [ 26 ] these gold electrodes can help reduce the contact resistance and limit resistance variation that may arise from the contact between the testing jaws and the MBPS. According to our earlier work, [ 29 ] the contact resistance was ≪1 ohm, while the nominal resistance of the MBPS was approximately 1 kohm. Therefore, it is reasonable to ignore the contact resistance in the FEM analysis.…”