Concrete has been the backbone of human civilization for thousands of years, shaping our homes, bridges, and cities.
Now, researchers at MIT believe it can do something entirely new: store electricity.
Imagine walls, sidewalks, or parking lots that double as batteries, providing energy storage right where it’s needed.
Thanks to new advances in electron-conducting carbon concrete, known as ec³ (pronounced “e-c-cubed”), this futuristic idea is coming closer to reality.
This special type of concrete is created by mixing cement, water, ultra-fine carbon black, and electrolytes. Together, these ingredients form a conductive “nanonetwork” inside the concrete that can store and release energy, much like a giant supercapacitor.
Early versions of ec³ already showed promise, but the latest research has made a dramatic leap.
By experimenting with new electrolytes and improved manufacturing methods, MIT scientists have increased its energy storage capacity by tenfold.
Just last year, meeting the daily energy needs of a typical home would have required about 45 cubic meters of ec³—roughly the amount of concrete in a basement.
Now, that same task can be done with only 5 cubic meters, the size of an ordinary basement wall. This jump in performance means concrete “batteries” could become practical for homes, buildings, and even large-scale infrastructure projects.
The breakthrough came from a better understanding of how carbon black particles arrange themselves within the concrete.
Using advanced imaging techniques called FIB-SEM tomography, researchers reconstructed the nanonetwork in 3D and found it forms a fractal-like web around the concrete’s pores.
This web allows electrolytes to flow and electrons to move through the system efficiently, making energy storage possible. With this knowledge, the team fine-tuned the type and concentration of electrolytes added to the mix.
The results were impressive. The scientists discovered that even common electrolytes like seawater could work, opening the door to coastal and marine applications.
Organic electrolytes turned out to perform best, especially those made from simple compounds found in everyday products.
A cubic meter of this enhanced ec³—about the size of a refrigerator—can store over 2 kilowatt-hours of energy, enough to run an actual refrigerator for a day.
Unlike traditional batteries, which eventually degrade, ec³ could last as long as the structure itself. Imagine roads that charge electric vehicles as they drive, or bridges that help stabilize the power grid. In Japan, ec³ has already been tested in heated sidewalks that melt snow without the need for salt.
The researchers also noticed something surprising when they built a small ec³ arch to demonstrate its strength and ability to power a light. As the load on the arch increased, the light flickered.
This suggests that ec³ might not only store power but also act as a built-in sensor to monitor structural stress in real time. In the future, buildings made of this material could “report” when they are under strain from heavy winds or other pressures.
For the researchers, the potential of ec³ goes beyond technical performance. Concrete is already the most widely used construction material in the world.
By giving it new abilities like energy storage, self-healing, and even carbon capture, they envision a future where the same structures that shelter us also help solve our energy challenges.
As MIT professor Admir Masic explains, “The Ancient Romans revolutionized architecture with concrete, and their buildings still stand today. We’re trying to continue that spirit by combining material science with architectural vision. Concrete powered the past, and now it may power the future.”
