MIT's Innovative Concrete Supercapacitor: A Game-Changer for Energy Storage
Science telegram channel
MIT's brilliant minds have made a groundbreaking discovery: a unique blend of cement, carbon black, and water can transform ordinary concrete into a powerful supercapacitor. This innovative concrete can store enough energy to power a household or rapidly charge electric vehicles.
Previously, we've explored the concept of using concrete as an energy storage medium. In 2021, researchers from Chalmers University of Technology demonstrated how concrete, embedded with carbon fiber mesh electrodes and mixed with carbon fibers for conductivity, could store substantial amounts of electrical energy. MIT's recent discovery, however, takes this concept a step further by eliminating the need for mesh electrodes, allowing the carbon black to form its own electrode structures during the curing process.
The secret lies in the reaction between water and cement. As the concrete begins to harden, the water forms a network of channels, into which the carbon black naturally migrates. These channels, resembling a fractal-like structure, create carbon electrodes with a vast surface area throughout the concrete. When bathed in a standard electrolyte like potassium chloride, these channels function as the plates of a supercapacitor.
Supercapacitors are known for their ability to charge and discharge almost instantly, offering higher power density and output than standard lithium batteries. However, there's a trade-off between the energy storage volume and the strength of the concrete, as adding more carbon black increases energy storage but weakens the final concrete.
The beauty of this technology lies in its scalability. Concrete is often used in large quantities, and an average American home built on a standard five-inch-thick concrete slab uses about 31 cubic yards of concrete. The MIT team estimates that a block of nanocarbon black-doped concrete of 1,589 cubic feet can store around 10 kWh of electricity. This is enough to cover about a third of the power consumption of an average American home, or to significantly reduce your grid energy bill when paired with a decent-sized solar rooftop array.
The team has successfully tested these concrete supercapacitors on a small scale and is now working on larger-scale demonstrations. According to MIT Professor Franz-Josef Ulm, this technology is super-scalable. "You can go from 1-millimeter-thick electrodes to 1-meter-thick electrodes, and by doing so basically you can scale the energy storage capacity from lighting an LED for a few seconds, to powering a whole house," says Ulm.
The potential applications of this technology are vast. It could be paired with roadside solar panels and inductive charging coils to create super-quick, drive-through wireless EV charging roads. It could also be used in the foundations of large grid-based energy storage facilities, providing quick jolts of power to the grid as well as longer-duration contributions at lower power.
However, there are still many questions to be answered. It's unclear whether this kind of concrete would be suitable for outdoor use where it'll get wet, or whether these concrete supercapacitors can practically be poured on-site to self-assemble in situ. The safety of touching these concrete supercapacitors is also yet to be determined. Nonetheless, this fascinating project promises to revolutionize the way we think about energy storage.
____