3D-Printed Electrode Design Boosts Redox Flow Battery Performance by 52 Percent

A Better Electrode from a 3D Printer

Researchers at the University of Waterloo think they can make grid-scale batteries safer and more efficient by borrowing shapes from nature. Led by chemical engineering professor Dr. Maxime van der Heijden, the team 3D-printed porous electrodes for redox flow batteries and found that one geometry, inspired by triply periodic minimal surfaces, improved performance by 52 percent compared with conventional designs.

The work, published in the Journal of Energy Storage, focuses on a type of battery that stores energy in liquid electrolytes held in external tanks. Unlike the lithium-ion cells in phones and electric cars, redox flow batteries use water-based fluids that do not catch fire. That makes them attractive for storing wind and solar power at the scale of neighborhoods, factories, or grid substations.

Why Geometry Matters

In a redox flow battery, the electrode is where the chemical reactions happen. The liquid has to reach as much of the electrode surface as possible, but it also has to flow smoothly without creating dead zones or excessive pressure drops. Traditional carbon-felt electrodes are cheap and workable, but their internal structure is random. That randomness leaves some surface area underused and some flow paths blocked.

3D printing lets the researchers control the structure precisely. They tested several repeating geometries and found that a diamond-shaped TPMS pattern worked best. These shapes, which resemble structures found in biology, spread the liquid evenly while keeping plenty of surface area active. After printing the polymer lattice with a digital light-processing printer, the team heat-treated it to turn the plastic into a conductive carbon scaffold.

The electrodes then went into real flow cells and a working vanadium redox flow battery. They worked. That matters because lab demonstrations often fail when engineers try to scale them up.

What This Means for Renewable Energy

Wind and solar are intermittent. The sun does not shine at night, and the wind does not blow on demand. Grid operators need ways to store surplus energy when generation is high and release it when it is low. Lithium-ion batteries do this today, but their cost, fire risk, and limited cycle life make them less appealing for multi-hour or multi-day storage.

Redox flow batteries are a natural fit for that longer-duration role because capacity can be increased just by adding bigger tanks. The catch has always been cost and efficiency. If 3D-printed electrodes can push performance up by half, the economics start to look very different.

Van der Heijden's team is not pretending the problem is solved. The next steps are to increase surface area further, refine manufacturing, and explore design tools that can optimize electrodes for specific chemistries. But the proof of concept is there: a 3D-printed electrode, shaped like something that grew in nature, can make renewable energy storage safer and cheaper.