3D Printed Electrodes Could Make Renewable Energy Storage More Efficient

Storing energy from wind and solar farms remains one of the harder problems in the clean energy transition. Lithium-ion batteries dominate small-scale storage, but grid-level applications need something safer, cheaper, and easier to scale. Redox flow batteries fit that profile: they store energy in liquid electrolytes held in external tanks, so you can increase capacity simply by using bigger tanks.

The catch is efficiency. The chemical reactions that store and release energy happen on the surface of electrodes inside the battery. Getting the liquid electrolyte to contact as much of that surface as possible, while keeping resistance low, is the engineering bottleneck. Researchers at the University of Waterloo set out to improve that with a 3D-printed design.

Nature-inspired internal geometry

Led by nanotechnology engineering professor Maxime van der Heijden, the team designed porous electrode structures using triply periodic minimal surface geometries. Those are repeating 3D shapes found in natural structures like butterfly wings and cell membranes. The team tested several TPMS variants and found that a diamond-style geometry worked best, pushing battery performance up by 52 percent over conventional designs.

The electrodes were printed with a digital light processing (DLP) 3D printer and then heat-treated to convert the polymer structures into conductive carbon capable of carrying current. The resulting material combines mechanical strength, high surface area, and open channels that let the electrolyte flow through with minimal resistance.

Tested in a real battery

The designs were validated in laboratory flow-cell experiments and in a working vanadium redox flow battery. The proof-of-concept results, published in the Journal of Energy Storage, show that 3D-printed electrodes can function inside an operating flow battery system.

Van der Heijden notes that the same approach could apply to electrolyzers used for hydrogen production, where efficient fluid movement matters just as much. The underlying principle is the same: use additive manufacturing to design the internal architecture of a material instead of accepting whatever structure a conventional mould produces.

Why this matters now

Grid-scale storage demand is growing fast as more wind and solar capacity comes online. Flow batteries using water-based electrolytes are safer than lithium-ion alternatives, but their efficiency has historically lagged. A 52 percent improvement in mass transport changes the economics enough to make flow batteries competitive in markets where they previously lost out. If the design can be manufactured at scale, it could accelerate deployment of longer-duration renewable energy storage.