A team of researchers from MIT has developed a new type of conductive concrete capable of storing and releasing electricity, turning structural elements such as walls, sidewalks or bridges into real “building batteries”. This material, called ec3, combines cement, water, ultrafine carbon black and electrolytes, generating an internal network that allows electron conduction and energy storage, opening the door to buildings that can fulfill a dual function: structural support and large-scale energy storage.

Thanks to its composition and the internal organization of the components, the ec3 has managed to multiply its energy capacity by ten compared to previous versions. While in 2023 45 cubic meters were needed to cover the daily consumption of a home, now about 5 cubic meters is enough, a volume similar to that of a basement wall. A single cubic meter can store more than 2 kWh, enough to power a refrigerator for a day.

Early tests show that the material not only supports load, but can also generate electricity. For example, a small arc of ec3 managed to power an LED light, which flashed when the structure was put under stress, suggesting that in the future buildings could monitor their own structural state. In Japan, sidewalks built with this concrete have proven their ability to generate heat and melt snow, thanks to their thermal conductivity.

The practical applications of ec3 are broad and go beyond research: it could be integrated into walls, floors or sidewalks to store energy generated by solar panels or wind turbines, acting as a reserve during the night or on cloudy days. It also allows urban infrastructures to be managed intelligently, regulating temperature, monitoring structural stresses or contributing to the energy efficiency of residential and commercial buildings.

The development of the ec3 is inspired by Roman engineering and seeks to combine architectural vision with advanced materials science. One of its objectives is to facilitate the energy transition, which makes it possible to store energy generated by renewable sources without relying on conventional batteries based on scarce or polluting materials.

During the Boston Innovation for Construction Program, recently organized by the Barcelona ConTech Hub, attendees were able to learn first-hand about these advances through the exhibition of Admir Masic, co-director of the MIT EC³ Hub and Associate Professor at the MIT Department of Civil and Environmental Engineering. Masic stressed that concrete, the most widely used building material in the world, has even greater potential if it is harnessed for energy storage and sustainability, opening the door to new ways of building and managing urban infrastructure.