MIT Boffins Build Battery Alternative Out of Cement, Carbon Black, and Water
Long-time Slashdot reader KindMind shares a report from The Register: Researchers at MIT claim to have found a novel new way to store energy using nothing but cement, a bit of water, and powdered carbon black -- a crystalline form of the element. The materials can be cleverly combined to create supercapacitors, which could in turn be used to build power-storing foundations of houses, roadways that could wirelessly charge vehicles, and serve as the foundation of wind turbines and other renewable energy systems -- all while holding a surprising amount of energy, the team claims. According to a paper published in the Proceedings of the National Academy of Sciences, 45 cubic meters of the carbon-black-doped cement could have enough capacity to store 10 kilowatt-hours of energy -- roughly the amount an average household uses in a day. A block of cement that size would measure about 3.5 meters per side and, depending on the size of the house, the block could theoretically store all the energy an off-grid home using renewables would need." [...] Just three percent of the mixture has to be carbon black for the hardened cement to act as a supercapacitor, but the researchers found that a 10 percent carbon black mixture appears to be ideal. Beyond that ratio, the cement becomes less stable -- not something you want in a building or foundation. The team notes that non-structural use could allow higher concentrations of carbon black, and thus higher energy storage capacity. The team has only built a tiny one-volt test platform using its carbon black mix, but has plans to scale up to supercapacitors the same size as a 12-volt automobile battery -- and eventually to the 45 cubic meter block. Along with being used for energy storage, the mix could also be used to provide heat -- by applying electricity to the conductive carbon network encased in the cement, MIT noted. As Science magazine puts it, "Tesla's Powerwall, a boxy, wall-mounted, lithium-ion battery, can power your home for half a day or so. But what if your home was the battery?"
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