Researchers at the Massachusetts Institute of Technology (MIT) have discovered that mixing concrete and carbon black with water can create a supercapacitor for energy storage.
According to New Atlas, the energy harvested from this concrete block could be sufficient to power a household or rapidly charge an electric vehicle.
The MIT research team reported that a 45m³ block of concrete mixed with nano-sized carbon black can store approximately 10kWh of electricity—enough to meet about one-third of the average electricity consumption of a household in the United States.
Concrete and water, with a small amount of carbon black mixed in, transform concrete into an energy-storing supercapacitor – (Photo: MIT).
According to MIT, carbon black will form interconnected electrode structures during the hardening process with the concrete.
This process takes advantage of how water and concrete react with each other: water creates a branching “channel” network within the concrete as it begins to solidify, and carbon black naturally moves into those channels.
These channels exhibit a fractal structure, with larger branches splitting into smaller ones. This creates carbon electrodes with a very large surface area that runs throughout the concrete.
Supercapacitors can charge and discharge almost instantly. Therefore, their energy density and output are often much higher than what is achieved with standard lithium batteries.
The research team has tested these concrete supercapacitors on a small scale. They cut pairs of electrodes to create small 1V supercapacitors and used three of these to light a 3V LED. The team is currently working on blocks the size of car batteries, targeting a capacity of 10kWh.
Professor Franz-Josef Ulm of MIT, a co-author of the study, referred to this as a super-scalable technology: “You can go from electrodes that are 1mm thick to electrodes that are 1m thick. In that way, you can essentially scale the energy storage capability from lighting an LED for a few seconds to powering an entire house.”
The research has been published in the Proceedings of the National Academy of Sciences (PNAS).
