Storing energy in electrified cement is still a largely untapped opportunity, despite the article in Science journal that we link to below. Back then, on July 31, 2023, Robert S Service explained how this technology could turn buildings into renewable energy storage devices. His article summarized research at Massachusetts Institute of Technology.
Potential For Storing Energy in Electrified Cement
‘Electrified cement’ in the context of Robert S Service’s article, is a cement-based supercapacitor. This is a product of mixing carbon black, graphene, or metal oxides into cement, to create a porous structure. This structure is then able to store, and release electricity.
The device in question consisted of two electrically conductive plates, with an ion-conducting electrolyte, and a thin membrane separating them. Positively charged ions from the electrolyte accumulated on one plate, as the device charged. While negatively charged ions accumulated on the other plate.
However, that was not all there was when it came to storing energy in electrified cement. The amount of energy stored depended on the total surface area of the supercapacitor’s two conductive plates. Researchers had tried to incorporate these into concrete for decades, without success.
The Problem With Cement and the Breakthrough Solution
The problem that previous researchers faced, was cement (a primary ingredient of concrete) is a bad conductor. Previous researchers had tried to resolve this with highly conductive forms of carbon without success, and so there was an impasse.
And then, Franz-Josef Ul, and his colleagues at Massachusetts Institute of Technology (MIT) had a bright idea. They laid their hands on some powdered carbon black, mixed a small amount of it with cement, and added water. They must have been frustrated by the way the carbon black granules clumped together.
And then they noticed something. The clumped carbon black created a network of interconnected tendrils through the cement! Ul and his team cut this ‘wired cement’ into small, button-size plates, added a membrane and a simple electrolyte, sealed the sandwich structure, and the capacitors lit up LED lights.
The researchers concluded a 45-cubic-meter network could power an average home, after charging. There has been some progress with bringing this idea to market.
From where we sit, this process seems frustratingly slow. We are curious to know why storing energy in electrified cement is taking so long to come to fruition.
More Information
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