Researchers at the Massachusetts Institute of Technology (MIT) have developed a new form of concrete that can both support structures and store electrical energy. The material, called electron-conducting carbon concrete (ec³), combines cement, water, and ultra-fine carbon black nanoparticles to form a conductive internal network. This enables the concrete to function as a supercapacitor, storing and releasing energy like a rechargeable battery — but built directly into the fabric of buildings and infrastructure.

From Structure to Energy Storage

Traditionally, concrete serves purely structural purposes. With ec³, MIT’s team envisions walls, bridges, pavements, and foundations that also act as distributed energy-storage systems. Recent developments have increased the material’s energy capacity tenfold: where powering an average home once required 45 cubic metres of ec³, the same can now be achieved with just five.

Such “multifunctional concrete” could drastically reduce the environmental impact of energy storage, avoiding the use of scarce or toxic materials found in traditional batteries. “Concrete is already the world’s most used construction material — why not use that scale to create other benefits?” asks Admir Masic, co-director of MIT’s EC³ Hub.

Nanotechnology and Circular Design

Using high-resolution imaging, researchers discovered that the carbon network inside ec³ forms a fractal-like web that allows electrolytes to move and charge to flow efficiently. This self-organising nanoscale structure was key to the material’s breakthrough performance.

The team also tested various electrolytes, including organic compounds and even seawater, opening possibilities for coastal or marine applications such as offshore wind foundations. By mixing electrolytes directly into the cement slurry, they created thicker electrodes with higher energy density — up to 2 kilowatt-hours per cubic metre, roughly enough to power a refrigerator for a day.

Toward Smart, Self-Monitoring Structures

Beyond storage, ec³ may also offer real-time structural health monitoring. In tests, a small ec³ arch powered an LED whose brightness changed under load, suggesting that stress could be detected through electrical feedback. Future structures could therefore signal fatigue or damage through their own energy output.

The material’s durability, recyclability, and potential for integration into existing construction systems make it a compelling candidate for sustainable design. Applications under development include heated pavements in cold climates, energy-storing building façades, and roads that charge electric vehicles.

A Step Toward Energy-Positive Architecture

As the world transitions to renewable energy, materials like ec³ could help close the storage gap — providing carbon-efficient, long-lasting, and locally produced alternatives to lithium-based batteries.

By merging ancient building materials with cutting-edge nanoscience, MIT’s researchers are reimagining concrete as not just the foundation of cities — but also their power source.

Source: MIT
Photo: MIT EC³ Hub