“Energy-Storing Concrete” Unveiled for the First Time, Industry Association Officially Launched
September 30, 2025
Aizawa High-Pressure Concrete Co. (Tomakomai, Hokkaido) unveiled the world’s first standard energy-storing concrete module and held a lighting ceremony at the “Yui” technology event on September 25 at its R&D base, RDM Fukushima Center in Namie, Fukushima Prefecture.
Energy-storing concrete functions as a supercapacitor, created by adding carbon black (fine carbon particles) into concrete to provide conductivity and act as an electrode. The technology is being jointly developed with the Massachusetts Institute of Technology (MIT).
A battery cell with an output of about 1V is formed by sandwiching a separator (fiberglass filter paper) impregnated with KCl electrolyte between two 45cm-square electrodes. Stacking 25 layers produces a unit output of about 25V, with dimensions of 590 × 590 × 1280mm. Connecting four such units yields a standard module with an output voltage of 100V.
Left Image – Structure of a Single Storage Unit
-
Electrode size: 450 × 450 mm
-
Components:
-
Positive electrode (ec3, anode)
-
Separator (fiberglass filter paper with KCl electrolyte)
-
Negative electrode (ec3, cathode)
-
-
Stacked layers are enclosed in a concrete housing (bottom, middle, top parts).
-
Prestressed steel (PC bars) are used for reinforcement, compression, and airtight sealing.
-
Overall size of one unit: about 590 × 590 × 1280 mm
Right Image – Standard Module
-
Formed by 4 units connected together.
-
Size of each unit: 500 × 590 × 1280 mm
-
Output voltage:
-
~25V per unit
-
100V for a 4-unit standard module
-
Performance (as reported)
-
Storage capacity (4-unit module): ~300 Wh
-
Energy efficiency: 90–95% (MIT test results)
-
Usable energy: 270–285 Wh
-
Applications:
-
Can power a 5V LED lamp (10Wh) for ~24 hours
-
Can charge a smartphone (iPhone 17) about 18 times
-
The separator is sealed within a concrete casing to retain moisture, with the interior coated using swimming-pool waterproof lining, rubber gaskets installed at joints, and prestressed steel (PC bars) compressed from above to ensure airtightness. Water leakage tests have been conducted to confirm safety.
A standard module (four units) has a storage capacity of about 300Wh, with an energy efficiency of 90–95% (MIT test results) and usable capacity of 270–285Wh. When fully charged, it can power a 5V LED lamp (10Wh) for around 24 hours, or recharge an iPhone 17 approximately 18 times.
At the event, LED lighting was powered by electricity stored in the module, which was charged using power supplied by a Toyota MIRAI fuel cell vehicle. The hydrogen for MIRAI was produced using solar power at the FH2R – Fukushima Hydrogen Energy Research Field in Namie.
At the same time, the Energy-Storing Concrete Industry Association held its first joint meeting, bringing together 45 concrete manufacturers and related companies from across Japan. The association aims to promote product development using this technology and establish a nationwide dissemination system.
