The Power-Storage-Brick

The same bricks used to build homes can be transformed into energy-storing units that hold electricity like batteries, according to a study by researchers at Washington University. The bricks are coated with a polymer that conducts electricity and absorbs ions.

Motors lift the bricks to high levels when wind and solar produce more power than is being used, then lower them to generate electricity. The entire process requires very little concrete or water.

Energy storage

Bricks are one of the oldest building materials around, but engineers at Washington University in St. Louis have found a way to turn them into pseudo-batteries that can conduct and store electricity. A single brick stores enough power to illuminate an LED light bulb, and can be charged 10,000 times without losing more than 10 per cent of its energy. The process is relatively inexpensive, and the bricks can be recycled again and again.

To make the bricks into energy storage devices, researchers pumped acid vapors through their pores and used a sulfur-based compound that reacts with iron to form a polymer coating. The resulting bricks are riddled with nanofibers of the conducting polymer PEDOT, which allows them to absorb and conduct electricity. The red pigment in the bricks also acts as a natural electrolyte, helping the bricks retain their charge.

The bricks are technically supercapacitors, which differ from batteries in a few key ways. Supercapacitors can store large amounts of energy, but they cannot hold that charge for as long as batteries can. Still, the technology could be useful in a number of applications.

For example, it would be a good solution for electric vehicles that use product-category/powerwall demand charges or tariffs that are based on the time of day when they use power. It would also be a great solution for power plants that operate on renewables, which are often subject to a lot of peaks and troughs.

Lighting

Bricks are one of the most familiar building materials on earth. They’ve been used to construct Neolithic dwellings, ranch-style houses, and modern McMansions for thousands of years. But now, researchers at Washington University have found a way to transform bricks into pseudo-batteries that can store and conduct electricity. The team pumped iron-oxide-rich red bricks with specific vapors to produce polymers that coat the brick’s microscopic pores, making them capable of conducting electricity. The process is simple and inexpensive, and it can be performed on brand new bricks or old ones.

The coated bricks act as supercapacitors, which hold energy as static electricity (versus the chemical reactions that occur in batteries). They can also be charged and discharged more quickly than traditional batteries. In tests, a single coated brick could power a green LED light for 10 minutes — even while submerged in water. The technology is still in the proof-of-concept stage, but it could eventually make it possible to build walls that simultaneously serve as both structural supports and energy storage devices.

The research is published in the journal Nature Communications. But the researchers warn that the bricks aren’t yet ready for commercial use. A coated brick costs three times as much as a standard brick, and it isn’t strong enough to be used for load-bearing walls.

Powering devices

Whether they were erecting Neolithic dwellings, ranch-style homes or modern McMansions, bricks have been builders’ favorite construction material for thousands of years. Now, chemists have identified a new potential solar system for these omnipresent building blocks: They can be transformed into energy storage devices capable of turning on LED lights through a series of reactions.

The team from Washington University in St. Louis used chemical vapors to react with red brick’s iron oxides, coating them with a network of plastic nanofibres. They also infused the bricks with a conductive polymer called PEDOT, which acts like an ion sponge to conduct electricity. The end result is a brick that can charge to 3 volts in 10 seconds, and power a green LED light for about ten minutes on a single charge.

D’Arcy explains that his team’s bricks are technically supercapacitors, not batteries. Supercapacitors store electric charges but can’t deliver long-term energy as a battery can, he writes in The Conversation.

While much work remains to be done, the proof-of-concept bricks represent “food for thought” in an industry looking for ideas for storing renewable energy, he says. For example, rooftop solar panels could be wired to charge the bricks, providing in-house backup power for lighting and other small appliances when the sun isn’t shining. The research was published this week in Nature Communications.

Battery replacement

Giant bricks may not be the first thing that comes to mind when talking about energy storage, but they are key to a gravity-based system that could help us manage our growing dependence on renewable power. Developed by a company called Energy Vault, the system uses energy generated when wind and solar production is high to lift 30-tonne bricks into the air inside a special building. The bricks store what’s known as potential energy, like a stretched spring, and when they are lowered back down, the energy they release is used to power power grids.

Scientists at Washington University in St. Louis have taken the idea a step further by pumping cheap, iron-oxide-rich red bricks with specific vapors that form polymers, transforming them into pseudo-batteries that can conduct and store electricity. The bricks can hold enough charge to light up an LED bulb, and they cost only about $3 each. When paired with solar panels, they can even keep your lights and phone charged for days.

As cities repair and repurpose their industrial heritage brick architecture (as discussed in Reprogramming the City), these brick batteries could be woven into buildings, enabling them to function as on-demand energy sources. They could be charged with solar, wind, geothermal, or other on-site renewable energy sources, and when the time comes, they can be used to replace gasoline generators that make noise, smoke, and require frequent fuel refills.