Schulich researchers discover surprise ingredient for improved electricity grid capacity

University of Calgary researchers have found that one small change can make a big difference – particularly when it comes to electricity grid storage capacity.

Dr. Edward (Ted) Roberts, PhD, has been investigating battery storage options and was looking to increase the lifetime of a special kind of battery: a redox flow battery.

The Schulich School of Engineering professor and associate head (research) in the Department of Chemical and Petroleum Engineering hoped to modify the battery membrane with graphene, which is a unique carbon material measuring only one atom thick.

“We were surprised to find that, with the modified membrane, the battery efficiency and power density increased,” Roberts says. “Since the power density increases, this means that a smaller battery can be used for a given power requirement, reducing the cost of the battery.”

Flexible options

Redox flow batteries (RFBs) store electrical energy in liquids that are pumped through the battery.

Roberts says they are being developed for energy storage on electricity grids for things like managing intermittent renewable-energy generation.

For electricity grid storage, batteries are flexible and can be implemented anywhere, but they are expensive. Key metrics for batteries are the round-trip efficiency, power density, energy density and lifetime.

He adds that when you draw more power, efficiency drops, and a battery of a given size has a maximum amount of power it can produce.

“Other battery technologies such as lithium-ion don’t have the flexibility of RFBs to increase the amount of energy stored, as more batteries are needed to do that,” Roberts says. “RFBs offer design flexibility, have a longer lifetime and a lower cost per kilowatt-hour delivered over their lifetime.”

However, he points out the capital cost is relatively high, which previously limited RFB implementation.

Performance-driven

Dr. Ashutosh Singh, PhD’21, has been working with Roberts on the graphene production process and says there is a lot of potential with this development.

“The significant performance enhancement in flow battery performance is an indication of high quality of our graphene samples,” says Singh, a postdoctoral associate with Chemical and Petroleum Engineering. “We are presently working on scaling-up our reactor to produce more of this high-quality graphene material to use in many other fields.”

Singh believes there could be several applications for graphene, including solar cells, gas separations, filtrations and other critical industrial processes.

“This has the potential to make Calgary and Alberta one of the pioneers in this deep-tech space,” Singh says.

Powering up

Not only are the researchers excited about the possibilities, but partners have also come forward.

The University of Waterloo and Kitchener-based Evercloak Inc. are working on the technology for coating the membrance with the graphene, while Roberts says his team will test the technology using a small five-kilowatt commercial redox flow battery in a research microgrid that is being built on campus. The battery is being supplied by U.S. company, StorEn Technologies Inc.

Recently, the project received $307,000 of funding from Alberta Innovates to help cover its $477,000 budget. The remainder of the funding is coming from a previously approved NSERC Idea to Innovation (I2I) grant of $125,000 and $45,000 coming from the Canada Foundation for Innovation.

“The funding we have received is enabling us to accelerate the development of the technology,” Roberts says. “During the project, we plan to demonstrate the scale-up of both the graphene production and membrane-modification processes, which are key steps towards commercialization.”

He is also aiming to raise investment for the commercialization through the team’s startup, Bee Energy Inc.

The project runs until January 2023.