Building materials are getting closer to doubling as batteries

Improved carbon-cement supercapacitors could turn the concrete around us into massive energy storage systems. Concrete already builds our world, and an MIT-invented variant known as electron-conducting carbon concrete (ec, pronounced "e c cubed") holds out the possibility of helping power it, too. Now that vision is one step closer. Made by combining cement, water, ultra-fine carbon black, and electrolytes, ec creates a conductive "nanonetwork" that could enable walls, sidewalks, and bridges to store and release electrical energy like giant batteries. To date, the technology has been limited by low voltage and scalability challenges. But the latest work by the MIT team that invented ec has increased the energy storage capacity by an order of magnitude.