Home batteries hanging on a wall could be outmoded by electrified cement, developed by researchers at the Massachusetts Institute of Technology.

Embedded in the cement are supercapacitors, a kind of battery. A supercapacitor is made up of two plates able to conduct electricity, separated by an electrolyte and a membrane.  When the supercapacitor is charged, negative ions from the electrolyte migrate to one plate, positive ions to the other. The bigger or more numerous the plates, the more power that can be stored.

Unfortunately, cement is really bad at conducting electricity.

Various engineers have tried to solve that problem in recent years by littering the cement with forms of carbon that excel at conducting an electric charge, such as carbon nanotubes or graphene. The additives  work as intended, but are hard to produce in large quantities and, therefore, are prohibitively expensive for this kind of use.

At MIT, the researchers decided to try carbon black, a cheap, abundant carbon powder used in tires, paints, and other common products. Carbon black is also an excellent electrical conductor.

The group sprinkled carbon black into cement, which then was mixed with water, sand, and gravel to make concrete.

Because carbon black dislikes water, when water was added to the cement the carbon black particles tended to group together in long filaments through the cement that act like electrical wires. 

Next, the researchers sliced the electrified cement into bits the size of a small coin, added an electrolyte and membrane, and sealed the package. They wired and charged the plates, flipped a switch, and the button-size device lit a group of LED bulbs.

If used to make the basement of an average-size house, the electrified concrete could store 10 kilowatt-hours of power, enough to supply a typical home for a day. The concrete could be charged from the grid during off-peak hours or store electricity created by wind turbines, solar panels, or other renewable sources.

The developers are now at work building a device able to store the power of a 12-volt battery. After that, they plan to continue scaling up the technology to commercial levels.

TRENDPOST: A Tesla Powerwall home battery can cost more than $10,000. If the same storage was built into a home’s foundation, slab, or concrete walls, the cost could be included in the cost of a mortgage, making home power storage more widely affordable and, therefore, more widely available.

The same technology could be used to electrify roadways to charge electric cars as they’re driving, a technology that has seen early tests in several places around the world. See “Electric Road Lets EVs Run Indefinitely Without a Battery Charge” (21 Jun 2022).