A European research team has developed a rechargeable cement-based battery that could turn buildings into giant energy storage units, combining structural strength with electrochemical function for the first time.
Engineered by scientists from the University of Bordeaux and the University of the Basque Country, the innovation transforms metakaolin — a synthetic clay derivative — into a durable geopolymer that doubles as a solid-state battery when paired with zinc and manganese dioxide electrodes. “This is more than a battery,” said lead author Dr Vadim M. Kovrugin, an energy storage specialist. “It’s a new material concept where infrastructure can actively contribute to the energy ecosystem.” The cement-like device delivered an energy storage capacity of 3.3 watt-hours per litre, positioning it as a promising tool for integrating battery systems directly into the built environment. It avoids the carbon-heavy production of traditional Portland cement and instead supports clean, efficient electrochemical storage.
Unlike earlier cement battery prototypes, which suffered from irreversible chemical reactions in alkaline environments, this geopolymer features a mildly acidic matrix that maintains zinc in ionic form, allowing for effective recharging through reversible plating and stripping. However, the researchers identified critical challenges. Hydrogen evolution during charging causes the formation of hexahydrated zinc sulfate, which damages the internal structure over time. To combat this, a modular, layered design was proposed, enabling replacement of degraded sections without compromising load-bearing strength. Water management also emerged as a key issue. The material lost significant moisture after 40 days of curing, reducing conductivity and battery performance. Yet raising hydration risks weakening its mechanical properties, prompting calls for more precise formulation and curing strategies.
Despite these hurdles, the team remains optimistic. “Our findings highlight the potential for integrating energy storage into building materials, paving the way for sustainable infrastructure development,” the study concluded. The innovation could lead to a new class of smart materials, where future buildings are not just energy-efficient but energy-generating — a potential turning point in sustainable architecture.
