A postdoctoral researcher at Queen’s University Belfast has developed a 3D printed flow battery cell that costs roughly £74 ($100) to build, after finding that a commercial version for his doctoral research would cost £2,000 to £3,000 ($2,700 to $4,050).

Dr. Hugh O’Connor and his supervisor decided to release the design for free to the international research community rather than sell it, aiming to standardize how scientists test flow battery technology.

Flow batteries store energy in liquids rather than the solid electrodes used in lithium-ion batteries, and are seen as important for storing renewable electricity for use when wind and solar generation are low. Most designs rely on vanadium, a metal that is more abundant than lithium but harder to access and subject to volatile pricing. QUB’s version is based on iron, which the researchers said is much easier to source.

How the design came together

“I started 3D printing them and I made lots of little tweaks. After a lot of trial and error, eventually these started to work really well,” O’Connor told the BBC.

O’Connor struggled to match his results against other published research and found colleagues elsewhere faced the same problem.

“We were at various conferences and meetings and calls; we noticed that other people were having the same problems, and lots of our colleagues were really interested in this work,” he said. “All of a sudden, we were in this position where we had this really nice, cheap cell, and we were all tackling the same problem.”

O’Connor briefly considered selling the design to colleagues, but after discussing it with his supervisor, decided to give it away instead.

“We kind of saw it as an opportunity to grow our network rather than make a small amount of money, and we feel like it can really benefit this technology,” he said.

The design uses about 10 components, including printed housing pieces, a membrane, gaskets, electrodes and current collectors, and ships with a step-by-step guide.

“It was really important that we sent out an Ikea-style instruction manual to our participants. And I think they followed it quite well,” O’Connor said.

Standardizing research across institutions

Dr. Josh Bailey, Illuminate Fellow at QUB’s School of Chemistry and Chemical Engineering, is among the researchers using O’Connor’s cell. He and the QUB team are co-leading reproducibility studies with several universities worldwide, using identical equipment to produce comparable results.

“We really honestly believe that flow batteries can be accelerated by these reproducibility studies and that the technology can be deployed more quickly if we’re all using the same standards. If we’re all going to get to 2050 and be at net zero, a lot more of our electricity needs to be stored in technologies like flow batteries,” Bailey said.

“It’s fun to know that the things that we’ve made here are out there and that we’re all working together to improve standards in flow batteries.”

O’Connor and Bailey are now testing larger cell stacks to gauge how the technology might scale for industrial use.