Ordinary red bricks can now be transformed into energy storage units, with a little help from a team of chemists and engineers at Washington University.
The bricks, which cost about $3 to make, are powerful enough to illuminate an LED light bulb — and could someday provide a new way to store renewable energy.
The technology hinges on the reddish pigment known as iron oxide, or rust, that gives bricks their color. Scientists pumped the bricks with several gases that react with the rust and produce a special, microscopic plastic capable of conducting electricity.
This network of plastic fibers coats the tiny pores inside the brick, said Julio D’Arcy, Washington University assistant professor of chemistry and study co-author.
The result: a dark blue “smart brick” that can store energy.
“I love the idea of adding value to things that are affordable, things that we take for granted,” said D’Arcy, who paid 65 cents per brick at a St. Louis hardware store. “The fact that they’re inexpensive means that they could be accessible to everyone.”
The specially designed bricks are technically supercapacitors, which store power as static electricity — versus the chemical reactions in batteries — and can recharge very rapidly.
In the future, a brick wall could potentially serve a dual purpose, said D’Arcy, providing both structural support and storage for electricity generated via solar panels and other forms of renewable energy.
“That’s the advantage to integrating the bricks into construction materials: Anyone can put a supercapacitor together without having to be an engineer,” he said.
Hongmin Wang, a Washington University graduate student who led the study, said the research “uses common materials to do some uncommon things.”
“The most attractive aspect about this technology is that it enables people to make electrodes as large as they want, by just stacking bricks,” Wang said in an email. “This is hard to achieve with conventional batteries because batteries are pressurized and when stacked, that may cause an explosion.”
The technology is likely a few years from being ready for the commercial market, due to its low energy storage capacity, which is currently 1% of that of a lithium ion battery.
By mixing certain transition metals into the bricks, like manganese, the research team hopes to increase the amount of energy they can store.
Producing fewer, stronger bricks “would be less wasteful of material and cheaper,” D’Arcy said. “If you truly want to make this accessible for everyone, for example, the undeveloped world, you want it to bring the price down.”
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