Scientists convert cement into a 'living' device capable of storing and recovering energy

In early lab trials, a team in Denmark turned common cement into a “living” energy device used for buildings, walls, and bridges. 

The material stores power and can regain performance after it is fed nutrients, even after periods of dormancy during simple maintenance cycles. In tests, the device reached about 81 Wh per pound.

The work was led by Dr. Qi Luo, a postdoctoral researcher in civil and architectural engineering at Aarhus University. His research focuses on low carbon cement and functional materials that add useful functions to structural elements now and at scale.

Energy from cement

Energy storage usually sits in separate batteries outside walls, wired to panels and meters and serviced by extra crews annually.

Folding storage into structure could make buildings that pull double duty without extra hardware during construction and use, reducing cluttered rooms.

A supercapacitor, a device that stores and releases charge quickly, fits this job because it tolerates fast cycling and frequent partial charges.

That makes it useful for smoothing solar power and running sensors between grid pulses on small sites, campuses, and remote stations.

Cities lose energy when electricity must travel far across feeders, especially in summer peaks, and line losses mount.

Local energy storage built into the cement of bridges and walls would keep more energy close to where it is used and reduce peak strain on distribution gear across neighborhoods.

How the material works

The team used electroactive microorganisms, bacteria that move electrons to nearby materials, to add a living charge layer inside cement and form a thin biofilm.

The species is Shewanella oneidensis, a lab workhorse in bioelectric experiments across many research groups worldwide today, often collected from river and lake sediments.

These microbes perform extracellular electron transfer, a process where proteins hand off electrons to an electrode using small redox molecules and outer membrane sites.

Once inside cured cement, they knit a redox network that holds charge instead of acting like an inert filler for the matrix, which is a big shift.

Cement stays harsh for life forms, so the group embedded a microfluidic network, small channels that deliver liquid nutrients, to keep cells active.

When cells slow down, that network can revive them with a simple feed made from salts and vitamins, restoring activity without replacing material.

Researchers also tuned the pore structure so ions move freely without sacrificing compressive strength that builders expect, using controlled water ratios during curing. The cement matrix still bears load like usual concrete, which is critical for adoption in real projects.

What the tests showed

In laboratory trials, the team reports results that either match or beat prior cement energy devices. Performance figures include about 80 percent recovery after reactivation and lighting an LED using six blocks in series in early prototypes.

One sentence from the team captured the spirit of the project and the long term goal. “We’ve combined structure with function,” said Dr. Qi Luo, in a statement after the demonstration.

The cement kept part of its charge behavior even when the microbes died because conductive shuttles persist for a while after growth.

Residual biofilm, a thin matrix that contains redox molecules, continued to pass electrons until the next nutrient feed, helping maintain charge routes.

Temperature mattered less than you might expect for a lab device during cycling under repeat testing. The device kept working near 32 degrees Fahrenheit and at heat levels common for buildings, which covers most indoor structures.

Where this fits with other ideas

Researchers worldwide are also exploring structural energy storage made from cement, carbon, and water. One approach uses a carbon black network in concrete to make a large supercapacitor for building scale storage.

The new study adds biology to that toolbox, not a one off trick for headlines, and patient iteration. It shows a path to turn cement from a passive frame into an active circuit that can wake after resting, inviting creative design.

Mixing living parts into a structural material raises questions about shelf life, especially under dry indoor air and salt exposure from roads.

For real buildings, engineers will want passive safety if the microbes stop working for a while, without any drop in strength or stiffness.

Designers can also pick use cases that do not need high energy where quick bursts matter more than long discharge.

Remote sensors, emergency lighting, and short grid smoothing would fit the current performance envelope in a practical way, helping early adoption.

Next steps for cement energy

Scaling matters as much as lab performance for this approach to succeed. Future versions must keep microbes healthy in an alkaline matrix, with simple maintenance and low cost service plans for owners.

Engineers will also need safe nutrient recipes and refill schedules that crews can follow on routine visits. Buildings could carry small reservoirs that refresh walls every few weeks in a short, metered pulse with clear inspection steps and log records.

Codes and standards will guide the roll out across regions as pilots begin. Inspectors will want clear tests for electrical performance, mechanical strength, and long term stability under moisture swings, with verification protocols spelled out for contractors.

Supply chains matter too across construction in every market. Any added components must be affordable, easy to ship, and straightforward for crews on site, with training that matches practice and simple disposal rules.

The study is published in Cell Reports Physical Science.

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