Researchers from Chalmers University of Technology in Sweden recently published an article outlining a new concept for rechargeable batteries made of cement, Tech Xplore reports. The concept involves a cement-based mixture with small amounts of short carbon fibres added to increase the conductivity and flexural toughness. Embedded within the mixture is a metal-coated carbon fibre mesh – iron for the anode, and nickel for the cathode. Luping Tang and Emma Zhang’s research has produced a rechargeable cement-based battery with an average energy density of 7 Watthours per square metre (or 0.8 Watthours per litre). The energy density is low in comparison to commercial batteries, but this limitation could be overcome thanks to the huge volume at which the battery could be constructed when used in buildings. The researchers see applications that could range from powering LEDs, providing 4G connections in remote areas, or cathodic protection against corrosion in concrete infrastructure.