Concrete already builds our world, and now it’s one step closer to powering it, too. Made by combining cement, water, ultra-fine carbon black (with nanoscale particles), and electrolytes, electron-conducting carbon concrete (ec³, pronounced “e-c-cubed”) creates a conductive “nanonetwork” inside concrete that could enable everyday structures like walls, sidewalks, and bridges to store and release electrical energy. In other words, the concrete around us could one day double as giant “batteries.”

As MIT researchers report in a new PNAS paper, optimized electrolytes and manufacturing processes have increased the energy storage capacity of the latest ec³ supercapacitors by an order of magnitude.

In 2023, storing enough energy to meet the daily needs of the average home would have required about 45 cubic meters of ec³, roughly the amount of concrete used in a typical basement. Now, with the improved electrolyte, that same task can be achieved with about 5 cubic meters, the volume of a typical basement wall.

“A key to the sustainability of concrete is the development of ‘multifunctional concrete,’ which integrates functionalities like this energy storage, self-healing, and carbon sequestration. Concrete is already the world’s most-used construction material, so why not take advantage of that scale to create other benefits?” asks Admir Masic, lead author of the new study, MIT Electron-Conducting Carbon-Cement-Based Materials Hub (EC³ Hub) co-director, and associate professor of civil and environmental engineering (CEE) at MIT.

The improved energy density was made possible by a deeper understanding of how the nanocarbon black network inside ec³ functions and interacts with electrolytes.

Using focused ion beams for the sequential removal of thin layers of the ec³ material, followed by high-resolution imaging of each slice with a scanning electron microscope (a technique called FIB-SEM tomography), the team across the EC³ Hub and MIT Concrete Sustainability Hub was able to reconstruct the conductive nanonetwork at the highest resolution yet. This approach allowed the team to discover that the network is essentially a fractal-like “web” that surrounds ec³ pores, which is what allows the electrolyte to infiltrate and for current to flow through the system.

“Understanding how these materials ‘assemble’ themselves at the nanoscale is key to achieving these new functionalities,” adds Masic.

Equipped with their new understanding of the nanonetwork, the team experimented with different electrolytes and their concentrations to see how they impacted energy storage density.

As Damian Stefaniuk, first author and EC³ Hub research scientist, highlights, “we found that there is a wide range of electrolytes that could be viable candidates for ec³. This even includes seawater, which could make this a good material for use in coastal and marine applications, perhaps as support structures for offshore wind farms.”

At the same time, the team streamlined the way they added electrolytes to the mix. Rather than curing ec³ electrodes and then soaking them in electrolyte, they added the electrolyte directly into the mixing water. Since electrolyte penetration was no longer a limitation, the team could cast thicker electrodes that stored more energy.

The team achieved the greatest performance when they switched to organic electrolytes, especially those that combined quaternary ammonium salts—found in everyday products like disinfectants—with acetonitrile, a clear, conductive liquid often used in industry. A cubic meter of this version of ec³—about the size of a refrigerator—can store over 2 kilowatt-hours of energy. That’s about enough to power an actual refrigerator for a day.

While batteries maintain a higher energy density, ec³ can in principle be incorporated directly into a wide range of architectural elements—from slabs and walls to domes and vaults—and last as long as the structure itself.

“The Ancient Romans made great advances in concrete construction. Massive structures like the Pantheon stand to this day without reinforcement. If we keep up their spirit of combining material science with architectural vision, we could be at the brink of a new architectural revolution with multifunctional concretes like ec³,” proposes Masic.

Taking inspiration from Roman architecture, the team built a miniature ec³ arch to show how structural form and energy storage can work together. Operating at 9 volts, the arch supported its own weight and additional load while powering an LED light.

However, something unique happened when the load on the arch increased: the light flickered. This is likely due to the way stress impacts electrical contacts or the distribution of charges.

“There may be a kind of self-monitoring capacity here. If we think of an ec³ arch at an architectural scale, its output may fluctuate when it’s impacted by a stressor like high winds. We may be able to use this as a signal of when and to what extent a structure is stressed, or monitor its overall health in real time,” envisions Masic.

The latest developments in ec³ technology bring it a step closer to real-world scalability. It’s already been used to heat sidewalk slabs in Sapporo, Japan, due to its thermally conductive properties, representing a potential alternative to salting.

“With these higher energy densities and demonstrated value across a broader application space, we now have a powerful and flexible tool that can help us address a wide range of persistent energy challenges,” explains Stefaniuk.

“One of our biggest motivations was to help enable the renewable energy transition. Solar power, for example, has come a long way in terms of efficiency. However, it can only generate power when there’s enough sunlight. So, the question becomes: How do you meet your energy needs at night, or on cloudy days?”

Franz-Josef Ulm, EC³ Hub co-director and CEE professor, continues, “The answer is that you need a way to store and release energy. This has usually meant a battery, which often relies on scarce or harmful materials. We believe that ec³ is a viable substitute, letting our buildings and infrastructure meet our energy storage needs.”

The team is working toward applications like parking spaces and roads that could charge electric vehicles, as well as homes that can operate fully off the grid.

“What excites us most is that we’ve taken a material as ancient as concrete and shown that it can do something entirely new,” says James Weaver, a co-author on the paper who is an associate professor of design technology and materials science and engineering at Cornell University, as well as a former EC³ Hub researcher.

“By combining modern nanoscience with an ancient building block of civilization, we’re opening a door to infrastructure that doesn’t just support our lives, it powers them.”

This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

A foundation created by Eric Schmidt, the former CEO of Google, will fund a project to send drone boats out into the rough ocean around Antarctica to collect data that could help solve a crucial climate puzzle. The project is part of a suite of funding announced today from Schmidt Sciences, which Schmidt and his wife Wendy created to focus on projects tackling research into the global carbon cycle. It will spend $45 million over the next five years to fund these projects, which includes the Antarctic research.

“The ocean provides this really critical climate regulation service to all of us, and yet we don’t understand it as well as we could,” says Galen McKinley, a professor of environmental sciences at Columbia University and the Lamont Doherty Earth Observatory and one of the lead scientists on the project. “I’m just really excited to see how much this data can really pull together the community of people who are trying to understand and quantify the ocean carbon sink.”

The world’s oceans are its largest carbon sinks, absorbing about a third of the CO2 humans put into the atmosphere each year. One of the most important carbon sinks is the Southern Ocean, the body of water surrounding Antarctica. Despite being the second smallest of the world’s five oceans, the Southern Ocean is responsible for about 40 percent of all ocean-based carbon dioxide absorption.

Scientists, however, know surprisingly little about why, exactly, the Southern Ocean is such a successful carbon sink. What’s more, climate models that successfully predict ocean carbon absorption elsewhere in the world have diverged significantly when it comes to the Southern Ocean.

One of the biggest issues with understanding more about what’s going on in the Southern Ocean is simply a lack of data. This is thanks in part to the extreme conditions in the region. The Drake Passage, which runs between South America and Argentina, is one of the toughest stretches of ocean for ships, due to incredibly strong currents around Antarctica and dangerous winds; it’s even rougher in the winter months. The ocean also has a particularly pronounced cloud cover, Crisp says, which makes satellite observations difficult.

“The Southern Ocean is really far away, so we just haven’t done a lot of science there,” says McKinley. “It is a very big ocean, and it is this dramatic and scary place to go.”

Chris Belasco, chief data officer (CDO) at the City of Pittsburgh, is focused on his team’s triumphs. While some data leaders might like to bask in the glory of their personal achievements, Belasco says success in the fast-moving digital age is very much about taking a collegiate approach: “The complaints should come to me, and the credit should go to the team.”

Belasco reached the CDO position by transferring his evaluation and analytics skills from academia to the public sector. He completed a PhD in public affairs and ran a unit at the University of Pittsburgh that conducted large impact evaluations on democracy and foreign assistance for the US Agency for International Development.

With a young family, he was keen to establish roots locally and joined the City of Pittsburgh in 2018 as enterprise project manager. He moved into the CDO role in 2022 and has relished the opportunity to help his organisation build data pipelines and refine its operational processes.

“I was fortunate enough to have good team members, some of whom are still here,” he said. “I’ve built the rest of the team, which has some incredibly sharp data engineering skills that I feel are a nice way to emphasise the capabilities of what the city has to offer.”

As a reflection of those capabilities, Pittsburgh achieved a higher level of Bloomberg Philanthropies’ What Works Cities Certification earlier this year. The certification recognised how the city has established data capabilities to inform policy, allocate funding, improve services, evaluate programmes, and engage residents. Belasco is proud of the achievement.

“Thirty-eight cities are either gold or platinum in the western hemisphere, and we are punching well above our weight class with the capabilities and practices that we’re able to demonstrate,” he says. “What we’re able to achieve through the work we’re doing, such as partnering with Astronomer, is pretty spectacular.”