Breakthrough cement mixtures that enable buildings to store energy

Researchers at Lancaster University have developed a cement mixture that could turn constructions into batteries.

The cement is made from material flyash and an alkaline solution, which is capable of conducting electricity. The mixture is known as potassium-geopolymetric (KGP) and its production is cheaper than-the most common used construction material-Portland Cement. Moreover, due to the fact that conductivity is achieved by potassium ions hopping through the crystalline structure, it does not demand expensive or complex additives.

In order to function, KGP utilizes the diffusion of potassium ions within the building to store electrical energy and to sense mechanical stresses. Researchers believe that in the future it would be able to produce about 200-500 Watts/m². The concept assumes that KGP would store energy to a power source during the day and discharge it during the night. It could be used in residences in the same way a solar panel operates but also in other energy demanding constructions, like street lamps. Professor Mohamed Saafi, from Lancaster University's Engineering Department, said: "We have shown for the first time that KGP cement mixtures can be used to store and deliver electrical energy without the need for expensive or hazardous additives. These cost-effective mixtures could be used as integral parts of buildings and other infrastructure as a cheap way to store and deliver renewable energy, powering street lighting, traffic lights and electric vehicle charging points."

KGP mixtures can also detect changes in mechanical stress provoked mainly by cracks. These changes influence the way potassium ions move through the structure, altering the material's conductivity. The effect can be measured to evaluate structural health. Professor Mohamed Saafi stated: "The concrete's smart properties makes it useful to be used as sensors to monitor the structural health of buildings, bridges and roads."

The researchers are publishing their study in the journal 'Composite Structures' in October 1^st, 2018. Additionally, their future intentions include the optimization of KGP mixtures and the examination of the 3D-printing potential in advanced architectural shapes.