Researchers from the Department of Architecture and Civil Engineering at Chalmers University of Technology, Sweden have recently published an article outlining a new concept for rechargeable batteries made of cement.
The ever-growing need for sustainable building materials poses great challenges for researchers. Doctor Emma Zhang, formerly of Chalmers University of Technology, Sweden, joined Professor Luping Tang's research group several years ago to search for the building materials of the future. Together they have now succeeded in developing a world-first concept for a rechargeable cement-based battery.
The concept involves first a cement-based mixture, with small amounts of short carbon fibres added to increase the conductivity and flexural toughness. Then, embedded within the mixture is a metal-coated carbon fibre mesh — iron for the anode, and nickel for the cathode. After much experimentation, this is the prototype which the researchers now present.
"Results from earlier studies investigating concrete battery technology showed very low performance, so we realised we had to think out of the box, to come up with another way to produce the electrode. This particular idea that we have developed, which is also rechargeable, has never been explored before. Now we have proof of concept at lab scale," Emma Zhang explains.
Luping Tang and Emma Zhang's research has produced a rechargeable cement-based battery with an average energy density of 7 Watt-hours per square metre (or 0.8 Watt-hours per litre). A modest estimate is that the performance of the new Chalmers battery could be more than ten times that of earlier attempts at concrete batteries. The energy density is still 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.