MIT concrete battery technology: how carbon cement supercapacitors could store renewable energy in buildings and roads

Researchers at MIT have developed a method to turn concrete into a supercapacitor by mixing cement with water and carbon black. The carbon black forms a conductive network inside the concrete, which can store electrical charge when soaked in an electrolyte. A volume of 45 cubic meters of this material can store about 10 kilowatt hours of energy, roughly the daily electricity use of an average home. The technology is still in early development. The team has demonstrated it at a small scale, powering an LED, and is now working on sealing the concrete to prevent the liquid electrolyte from drying out. If scaled successfully, the material could be used in building foundations to store solar power or in roadways to wirelessly charge electric vehicles. While the energy density is lower than lithium-ion batteries, the advantage is scale. Concrete is already used in massive quantities worldwide. Turning a fraction of that into storage could provide grid-scale backup for intermittent renewable energy without adding new materials or manufacturing lines.