[freebeard]

Via Hacker News:

www.science.org/content/article/electrified-cement-could-turn-houses-and-roads-nearly-limitless-batteries

Researchers have come up with a new way to store electricity in cement, using cheap and abundant materials. If scaled up, the cement could hold enough energy in a home’s concrete foundation to fulfill its daily power needs. Scaled up further, electrified roadways could power electric cars as they drive. And if scientists can find a way to do this all cheaply the advance might offer a nearly limitless capacity for storing energy from intermittent renewable sources, such as solar and wind.

So far, the cement devices are small, only big enough to power a few LED lightbulbs. But efforts are already underway to scale them up.

The cement devices are a kind of simplified battery called supercapacitors...... So, in recent years, several groups have made structural supercapacitors by spiking cement with highly conductive forms of carbon, such as graphene or carbon nanotubes. ..... In search of a cheaper alternative, Ulm and his colleagues turned to an age-old form of powdered carbon known as carbon black, which has been used since antiquity as a black pigment. Cheap and globally abundant, carbon black is also highly conductive.
.....
For structural concrete, the researchers found they could add up to 10% carbon black without compromising too much of its strength. Ulm says the group has patented its technology and is now working to scale it up to match the output of a 12-volt car battery.