Engineers utilize ancient materials to develop new ‘supercapacitor’ cement: It’s a ‘fascinating’ combination

Rick Kazmer
September 7, 2023·

The wise man built his house upon a … supercapacitor?

Engineers at the Massachusetts Institute of Technology believe that this could be the case as they continue working on a unique renewable-energy storage system created from cement, water, and carbon black. The latter material resembles fine charcoal, according to the MIT experts.

If the battery alternative proves successful, home foundations could soon be made from a unique mix of ancient and new materials, creating energy storage at home and beyond.

“The material is fascinating,” MIT professor Admir Masic said in a university report, “because you have the most-used man-made material in the world, cement, that is combined with carbon black, that is a well-known historical material — the Dead Sea Scrolls were written with it.”

It’s important as experts continue the search for effective storage for renewable energy from the sun, wind, and waves. Since those energy sources can only produce power during specific times, that power must be stored for later use.

For this invention, the MIT researchers have figured out how to make the chemistry that charges batteries work in cement. Part of the big breakthrough is including carbon black, which is highly conductive, into the mix. Water helps the carbon form “wire-like” structures in the cement as it dries. The material is soaked in a salty solution that is an electrolyte, which is key to the process, just like in regular batteries, all per MIT in a lengthy description of the process.

In short, some other key parts needed for the charge/discharge cycle are added, creating an environment that allows the supercapacitor to work. A big improvement is the use of readily  available materials like cement instead of lithium, which is rare and often takes invasive mining to gather.

The payoff is realized in the power storage. MIT researchers said that a nearly 59-cubic-yard piece of their cement, complete with nanosized carbon black, could store enough energy to power a house for a day.

“Since the concrete would retain its strength, a house with a foundation made of this material could store a day’s worth of energy produced by solar panels or windmills and allow it to be used whenever it’s needed. And, supercapacitors can be charged and discharged much more rapidly than batteries,” according to the research report.

The experts are still working out some specifics. The more carbon black is added, power storage capacity increases while structural strength is reduced.

One futuristic idea is to make concrete roads that can be charged with solar panels. A supercapacitor highway could then charge electric vehicles, similar to how certain cellphones can be juiced up wirelessly, per MIT.

The goal is for concrete to help create a cleaner planet instead of just contributing to the air pollution tally.

It’s “a new way of looking toward the future of concrete as part of the energy transition,” MIT Professor Franz-Josef Ulm said in the report.