Researchers at the Harbin Institute of Technology have developed 3D-printed cement-based supercapacitors that combine structural strength with energy storage, retaining around 95% of their initial capacity after 10,000 charge-discharge cycles.
Cement-based supercapacitors: a new frontier in smart constructio
Building materials capable of supporting structural loads while simultaneously storing electricity could transform the future of construction. Researchers at the Harbin Institute of Technology have taken a step towards this goal by developing 3D-printable cement-based supercapacitors. Their innovative cement-based printing material addresses the deterioration of electrochemical performance, demonstrating the ability to retain most of its original energy storage capacity even after thousands of charging and discharging cycles.
Although the findings remain largely confined to laboratory testing, they point to promising applications for future buildings.
“If building materials could not only support structures, but also store energy, sense their surroundings and even interact with people, buildings would become more than just passive shelters,” explains Jing Zhong, co-author of the study. “They could become truly intelligent environments.”
The advantages of structural cement-based supercapacitors
Demand for low-cost, large-scale and decentralised energy storage devices has increased in recent years. Supercapacitors are well suited to these requirements, offering high power density, rapid charging and discharging capabilities, and a long operational lifespan.
At the same time, structural supercapacitors, manufactured using conventional building materials, have attracted considerable attention because they can combine load-bearing capacity with electrochemical functionality in a single component. Cement-based supercapacitors are particularly promising in this respect.
The material’s excellent mechanical strength, combined with its porosity, makes it especially attractive compared with other alternatives currently under investigation. In these devices, cement-based materials can serve as both a solid electrolyte and a structural electrode.
However, achieving the right balance between electrochemical performance and mechanical properties remains a significant challenge.
Two major obstacles typically arise when transforming cement into a supercapacitor. First, the different layers, particularly the electrode and separator, tend to delaminate or develop cracks at their interfaces.
Second, conventional stacked-layer designs require ions to travel relatively long distances through the material’s thickness. As thickness increases, these longer transport pathways reduce electrochemical performance.
How 3D-printed cement-based supercapacitors work
To overcome these limitations, the researchers developed a monolithic supercapacitor using 3D printing technology.
More specifically, the team printed electrodes made from carbon nanotubes, carbon black and cement directly into cement mortar, which acts as the separator.
By creating a single integrated structure, this approach eliminates the risk of delamination between individual layers.
The electrodes were also arranged in an interdigitated configuration, replacing the traditionally long vertical ion transport pathway with a much shorter horizontal route. This design also increases the effective contact surface area.
The experimental results demonstrate the potential of the technology.
The 3D-printed cement-based supercapacitors achieved a compressive strength of 23.00 MPa, comparable to that of commercial concrete used for slabs and staircases.
At the same time, the devices delivered a power density of 0.49 mW/cm² and an energy density of 22.52 µWh/cm².
Although these values remain modest compared with those of the broader energy storage sector, they represent promising results for cement-based supercapacitors.
For example, three printed supercapacitors integrated into the same slab and connected together were capable of powering a small array of LED lights.
The researchers also demonstrated the devices’ durability. After 10,000 charge-discharge cycles, the supercapacitor retained approximately 95% of its initial capacity.
The team further established that the device operates reliably under moderate heating and cooling conditions. However, at temperatures approaching -18°C, its performance begins to decline.
Future research will therefore focus on improving the low-temperature performance of cement-based supercapacitors, an important consideration for their potential use in building applications.
The scientific study, Monolithic 3D-Printed Interdigitated Cement-Based Supercapacitors for Structural Energy Storage, was published in ACS Nano.
