Researchers develop concept for rechargeable cement-based batteries

Researchers from the Department of Architecture and Civil Engineering at Chalmers University of Technology in Gothenburg, Sweden, have created a concept for rechargeable batteries made of cement.

The concept involves a cement-based mixture with small amounts of short carbon fibers added to increase conductivity and flexural toughness. Embedded within this mixture is a metal-coated carbon fiber mesh—iron for the anode and nickel for the cathode. Several combinations for the electrodes were tested before the iron anode and nickel-based oxide cathode were found to yield the best results. Additionally, researchers had to experiment with different ratios of carbon fiber before finding an optimal mixture of around 0.5% carbon fiber to improve the cement-based mixture’s conductivity for the electrolyte.

The resulting cement-based battery has an average density of 7 watt-hours per square meter during six charge and discharge cycles—low in comparison to commercial batteries, but still potentially very beneficial to the built environment considering the large volume at which the battery could be constructed when used in buildings, bridges, dams, and other concrete structures.

The research team—led by Chalmers Professor Luping Tang and Emma Zhang, PhD, formerly with the university, now Senior Development Scientist at Delta of Sweden—envisions possible applications for the concept that range from powering LEDs, providing 4G connections in remote areas, and cathodic protection against corrosion in concrete infrastructure.

“It could also be coupled with solar cell panels to provide electricity and become the energy source for monitoring systems in highways or bridges, where sensors operated by a concrete battery could detect cracking or corrosion,” said Zhang.

Technical questions that need to be answered before commercialization of the concrete technology include extending the service life of the battery and the development of recycling techniques. The batteries would need to either be able to match the 50-100 year life of a typical concrete building or be made easier to exchange and recycle when their service life is over.

Despite these obstacles, the researchers are optimistic the concept has plenty to offer as a future building material that contributes to additional functions such as renewable energy sources.