Concrete that stores energy: A new era of sustainable construction begins at MIT

Can the walls of our homes become the batteries of the future?
Scientists at MIT have developed a technology that allows concrete not only to support structures but also to store electrical energy. The improved carbon-cement supercapacitors (ec³) could transform buildings, sidewalks, and bridges into active components of energy systems.

Concrete that conducts electricity

The new material — an electron-conducting carbon-cement composite (ec³) — is created by combining cement, water, ultrafine carbon black, and electrolytes. The result is an internal nanoscale network that conducts electrons, enabling concrete to store and release energy like a giant supercapacitor.

According to researchers at the MIT Electron-Conducting Carbon-Cement-Based Materials Hub (EC³ Hub), this innovation could one day allow energy storage directly within architectural elements — such as walls, foundations, and even roads.

From basement to wall – a tenfold leap in efficiency

Just two years ago, storing enough energy to power an average household for one day required about 45 m³ of ec³ — roughly the amount of concrete used in building a basement. Today, thanks to improvements in composition and the use of new electrolytes, only 5 m³ of material is needed.

Professor Admir Masic of MIT explains that the key lies in optimizing the carbon black nanoscale network and using organic electrolytes. One cubic meter of next-generation ec³ concrete can store over 2 kWh of energy — enough to power a refrigerator for an entire day.

Ecology meets engineering

Importantly, the new concrete does not require rare or toxic raw materials. It uses widely available ingredients, including organic compound-based electrolytes and even seawater. This makes ec³ suitable for use in coastal and offshore structures, such as components of offshore wind farm infrastructure.

Another advantage is the simplicity of the production process. Instead of complex post-casting impregnation stages, the MIT team developed a method where the electrolyte is added directly to the mixing water, allowing the casting of thicker, higher-capacity elements.

Arches, lights, and warning signals

To demonstrate ec³’s potential, researchers built a miniature concrete arch that simultaneously supported weight and powered an LED light. Interestingly, when the structure was subjected to stress, the light began to flicker.

Scientists suspect this is due to interactions between mechanical deformation and electric current flow, suggesting that such structures could one day monitor their own structural health.

Concrete of the future: energy storage in every wall

The ec³ technology is already being tested in practice. In Sapporo, Japan, it has been used to heat concrete pavement slabs, whose thermal conductivity eliminates the need for salt during winter.
In the future, carbon-cement concrete could serve as the foundation for roads that charge electric vehicles, off-grid homes, or cities with built-in energy storage systems.