3D-Printed Diamond Electrodes Boost Flow Battery Performance by 52%

What they built

A team at the University of Waterloo led by chemical engineering professor Maxime van der Heijden redesigned the porous electrodes inside redox flow batteries. Instead of conventional random pore structures, they printed diamond-shaped lattices using triply periodic minimal surface geometries.

The result: a 52 percent performance increase in lab tests. That is not a marginal gain. Flow batteries already excel at long-duration grid storage because they store energy in liquid electrolytes rather than solid cells. Better electrode geometry makes that advantage even sharper.

Why geometry matters

In a redox flow battery, liquid electrolyte flows past the electrode surfaces where the actual energy-storing reactions happen. If the liquid does not reach those surfaces evenly, the battery wastes capacity. The Waterloo team used 3D printing to control that internal structure precisely.

They printed the structures on a digital light-processing 3D printer, then heat-treated the parts to convert them into conductive carbon electrodes. The diamond TPMS configuration outperformed every other geometry they tested.

The renewable energy connection

Grid-scale storage remains the missing link for wind and solar. Batteries that can discharge for eight hours or more at utility scale smooth out the gaps when the wind dies or clouds roll in. Flow batteries handle that duration well, but their energy density has always lagged behind lithium-ion.

Van der Heijden put it plainly: "With 3D printing, we can design the internal structure of an electrode in ways that are difficult to achieve using conventional manufacturing. That gives us much greater control over how the liquid moves through the battery and reaches the surfaces where the energy-storing reactions take place."

What is next

The researchers plan to increase electrode surface area, refine their manufacturing methods, and explore additional design tools for electrode structures. They also tested the printed electrodes in a working vanadium redox flow battery, confirming the designs function in a real operating system.