Energy storage and building materials merge in a new rechargeable battery technology engineered at Chalmers University of Technology, Sweden. The functional cement-based battery multitasks as a sustainable structural component and as an energy storage medium for buildings.

Short carbon fibers are added to a cement-based mixture to increase conductivity and flexural toughness. A metal-coated carbon fiber mesh composed of iron and zinc for the anode and nickel oxides for the cathode is then embedded in the material.

A prototype rechargeable cement-based battery demonstrated an energy density of approximately 7 Wh/m2, 10 times greater than that achieved with earlier concrete-based batteries. While this value is low in comparison to commercial batteries, this limitation could be overcome by the large volume of battery material used in building construction. Cement-based electrodes fabricated with iron powder and nickel hydroxide powder were demonstrated to be rechargeable in liquid electrolytes and to power a small LED lamp for several hours.

Rechargeable cement-based batteries utilized as functional concrete. Source: Yen Strandqvist/Chalmers University of Technology

The researchers envision whole sections of multi-story buildings constructed of functional concrete. In addition to building-scale energy storage, the battery described in the journal Buildings could be paired with solar panels to power sensors embedded into highways, bridges and other concrete structures, or be deployed to deliver 4G connections in remote areas.