Researchers have developed a new form of carbon-cement concrete capable of storing electrical energy, opening possibilities for buildings and infrastructure that can also serve as large-scale energy storage systems.
Study: High energy density carbon-cement supercapacitors for architectural energy storage. Image credit: Francisco Duarte Mendes/Shutterstock.com
Importance of Concrete ‘Batteries’
The global transition from fossil fuels to a renewable energy-centered economy necessitates efficient, scalable, and sustainable energy storage solutions to manage fluctuating supply and demand. Electron-conducting carbon concrete (ec3) is a multifunctional material that offers a feasible approach to this problem by combining structural integrity with electrochemical energy storage capabilities.
Ec3 is prepared by combining water, ultra-fine carbon black particles, cement, and electrolytes. This blend forms a conductive nanonetwork within the concrete matrix that enables common structures like buildings, pavements, and bridges to potentially function as large-scale energy storage systems.
Current limitations include relatively low voltage, modest energy density compared with conventional batteries, and scalability challenges, though ongoing research aims to address these hurdles and refine the material. The ec3 concept aligns with the broader development of multifunctional concrete that integrates additional functionalities like energy storage, self-healing, and carbon sequestration.
Concrete is the most widely used construction material globally, and thus, incorporating such features on a large scale could significantly advance the sustainability and functionality of future infrastructure.
The Study and Findings
In a recent study, researchers provided insights into the nanoscale connectivity of the electrode’s conductive carbon network, investigated various material integration strategies and electrolyte compositions, and highlighted device scaling opportunities. The objective was to offer a viable approach for transitioning from a proof-of-concept to a practical alternative for large-scale energy storage.
Through electrolyte optimization, nanoscale three-dimensional (3D) imaging, and multicell stacking, the research team developed enhanced carbon-cement supercapacitors, able to create a robust energy storage medium from concrete. These energy-storing, high-voltage concrete components can support mechanical loads and also power electrical devices.
Optimized manufacturing processes and electrolytes significantly increased the demonstrated energy storage capacity of the latest ec3 supercapacitor. Using focused ion beam-scanning electron microscopy (FIB-SEM) tomography, researchers visualized the electrode’s percolating, fractal-like nano-carbon black network at the nanoscale, gaining critical insights into the material’s theoretical energy storage potential.
A proposed "cast-in electrolyte" method was also developed for improved manufacturing efficiency. This method is intended to allow the production of centimeter-thick electrodes without postcuring. However, this approach remains under optimization rather than a fully realized process.
In the developed prototypes, device performance scaled linearly with cell count and electrode thickness, and an analytical model was used to explain these scaling trends. The investigation of alternative organic and ionic electrolytes further improved electrochemical behavior. As a result, the theoretical modelling suggests that the volume of ec3 needed to power an average home’s daily energy requirements decreased substantially, from about 45 cubic meters in 2023 to just five cubic meters at the time of the study (September 2025).
Significance of the Study
Researchers successfully fabricated a 12 V (volt), 50 F (farad) supercapacitor module and a 9 V arch prototype that integrated energy storage into load-bearing architectural elements. This was realized by thoroughly understanding the nanocarbon black network within ec3 and its interaction with electrolytes.
Using FIB to sequentially remove the material’s thin layers, combined with high-resolution SEM imaging, researchers reconstructed the conductive nanonetwork at unprecedented resolution. They discovered the network forms a fractal-like ‘web’ surrounding the concrete’s pores, facilitating electrolyte infiltration and current flow.
Based on this insight, they experimented with diverse electrolytes and their concentrations, including seawater, therefore opening possibilities for marine and coastal applications like offshore wind farm support structures. Researchers also streamlined the manufacturing process by adding electrolytes directly into the mixing water, allowing the casting of thicker electrodes without electrolyte penetration limitation, increasing energy storage capacity.
The highest performance was attained using organic electrolytes, particularly those combining quaternary ammonium salts, common in disinfectants, with acetonitrile, a conductive industrial solvent. One cubic meter of this enhanced ec3 could theoretically store up to several hundred watt-hours of energy per cubic meter in current prototypes, with higher densities projected under optimized conditions. These densities are significantly below battery levels but sufficient for structural-scale storage applications.
While traditional batteries offer higher energy density, ec3’s ability to be integrated directly into architectural elements like slabs and vaults provides long-lasting, durable energy storage that can endure as long as the structure itself, marking a significant step toward sustainable, multifunctional infrastructure.
Inspired by Roman architecture, researchers built a miniature ec3 arch capable of supporting weight while powering a light-emitting diode (LED). The LED flickered under increased stress, indicating the potential of ec3 for monitoring real-time structural health.
Recent advances in ec3 development show its suitability for practical use. It is currently utilized to heat sidewalks in Sapporo, Japan, as a salt alternative. With higher energy densities and versatility, ec3 offers a sustainable solution for energy storage, especially important for renewable sources like solar power that require reliable storage for nighttime/cloudy conditions.
Unlike traditional batteries, ec3 uses abundant materials, enabling buildings and infrastructure to store energy efficiently. Future applications include roads and parking spaces that charge electric vehicles, and homes operating off-grid.
This approach effectively links energy systems and architecture, positioning ec3 as a promising new material system capable of helping to decarbonize construction and enable resilient infrastructure in the clean energy era.
Journal Reference
Stefaniuk, D., Weaver, J. C., Ulm, F. J., Masic, A. (2025). High energy density carbon–cement supercapacitors for architectural energy storage. Proceedings of the National Academy of Sciences, 122(40), e2511912122. DOI: 10.1073/pnas.2511912122, https://www.pnas.org/doi/10.1073/pnas.2511912122
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.