# Understanding the Current Distribution and Mass Transport Properties in 3D-Printed Architected Flow-Through Electrodes

## TL;DR

This study explores how 3D-printed lattice structures affect current and mass transport in flow-through electrodes for energy storage.

## Contribution

The paper introduces new scaling relationships (WaLattice and DaLattice–1) to predict and optimize electrochemical performance in architected electrodes.

## Key findings

- Mass-transfer coefficients vary with lattice geometry, with Octet structures showing the highest performance.
- Inertial effects become significant at Reynolds numbers above 3, especially in Octet lattices.
- Current distribution uniformity is influenced by lattice design and process conditions.

## Abstract

Architected materials offer promising advancements in
energy storage
by enabling highly customizable, high-surface-area, ordered, and low-defect
porous structures. This study investigates the current distribution
and mass transport within complex 3D-printed lattice electrodes under
flow-through conditions. Conductive lattices were fabricated using
microstereolithography followed by pyrolytic carbonization. Lattice
geometry effects were analyzed by varying the unit cell type [simple
cubic (SC), body- and face-centered cubic (BCC/FCC), IsoTruss, and
Octet], porosity, and current density. Current distribution uniformity
was investigated using a model high-efficiency copper deposition reaction.
Local film thickness distributions were predicted using a numerical
model and validated experimentally using micro-X-ray computed tomography.
Scaling relationships for informing electrochemical reaction conditions
and current uniformity are formulated as a modified lattice-based
Wagner number (WaLattice) and a corresponding
inverse Damkohler number (DaLattice–1). Validated models reveal that mass-transfer coefficients
scale as Octet > IsoTruss > FCC ∼ BCC > SC. Inertial
effects
become significant at Reynolds number Re > 3 and
are particularly pronounced in Octet structures due to an abundance
of struts oriented away from the fluid flow direction. The study underscores
the importance of electrode engineering and process conditions necessary
to tailor mass transport and current uniformities to various device
applications.