3D-printed TPMS electrodes improve the performance of redox flow batteries
An international research group led by the University of Waterloo has demonstrated that the internal geometry of electrodes, mathematically designed and fabricated with 3D printing, can substantially modify the behavior of redox flow batteries. The Diamond geometry achieved the best results in balancing mass transport and hydraulic resistance.
- Porous electrodes with TPMS structures fabricated using Digital Light Processing and converted into conductive carbon material
- Four geometries compared: Gyroid, Diamond, IWP, and Cubic
- Proof of concept tested on a vanadium redox flow battery with voltage efficiency of 76% at 50 mA/cm²
- The approach treats the electrode as a designed fluid-dynamic component, not as a random porous material.
TPMS structures instead of conventional porous materials
The group led by Professor Maxime van der Heijden redesigned the physical architecture of the electrode instead of modifying the battery chemistry.
The researchers used TPMS (Triply Periodic Minimal Surfaces) structures, periodically repeated minimal surfaces that offer precise geometric control. These architectures were fabricated using Digital Light Processing, a resin 3D printing technology.
After printing, the electrodes were subjected to heat treatment to convert them into conductive carbonaceous material. This process transforms the polymer resin into a carbon structure suitable for electron transport.
Comparison of four geometries
The study simultaneously analyzed mass transport, pressure drop, available surface area, and electrochemical behavior.
| Geometry | Main feature |
|---|---|
| Gyroid | Analyzed TPMS structure |
| Diamond | Best for redox transport with low hydraulic resistance |
| IWP | Analyzed TPMS structure |
| Cubic | Analyzed TPMS structure |
The Diamond geometry proved particularly effective. It facilitated the transport of redox species while keeping hydraulic resistance relatively low, a fundamental compromise for practical applications.
The University of Waterloo mentions a performance increase of 52% for the best configuration. This value refers to the improvement in mass transport and the trade-off between electrochemical performance and pumping losses, not a generic increase in battery efficiency or capacity.
Vanadium battery test
The proof of concept demonstrated the practical feasibility of the approach on a real laboratory vanadium redox flow battery.
The researchers installed one of the printed electrodes in a vanadium redox flow battery. The system achieved a voltage efficiency of 76% at a current density of 50 mA/cm².
This is a proof of concept, not a battery ready for grid installation. However, it demonstrates an important principle for additive manufacturing in the energy sector.
Electrodes as fluid-dynamic components
The approach changes the design paradigm: the electrode becomes an engineered component instead of a material with a random structure.
In redox flow batteries, the electrode can be treated as a designed fluid-dynamic component. This contrasts with the traditional approach that accepts porous materials with a substantially random structure, such as conventional carbon felt.
3D printing allows simultaneous optimization of multiple parameters: electroactive surface area, permeability, tortuosity of flow paths, and current distribution. The geometric control offered by TPMS makes this level of optimization possible.
Implications for stationary storage
Redox flow batteries separate power and energy more than conventional batteries, making them suitable for grid applications.
The work, published in the Journal of Energy
article written with the help of artificial intelligence systems
Q&A
Which 3D printing technologies were used for the electrodes?
Researchers used Digital Light Processing (DLP) technology to fabricate TPMS structures in resin. Subsequently, the electrodes underwent heat treatment to convert them into conductive carbonaceous material.
Which TPMS geometry offered the best performance?
The Diamond geometry achieved the best results by balancing redox species transport with low hydraulic resistance. This trade-off is crucial for improving the practical efficiency of redox flow batteries.
Which geometries were compared in the study?
The study analyzed four different TPMS geometries: Gyroid, Diamond, IWP, and Cubic. Each structure was evaluated for mass transport, pressure drop, and electrochemical behavior.
What performance improvement was recorded?
The University of Waterloo reports a 52% performance increase for the best configuration. This value specifically refers to the improvement in mass transport and the trade-off with pumping losses.
On what type of battery was the proof of concept tested?
The proof of concept was tested on a vanadium redox flow battery. Tests demonstrated a voltage efficiency of 76% at a current density of 50 mA/cm².
