Hydrogen or electric vehicles? Why the answer is probably both

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The distinct virtues of the two main emerging types of greener transport mean both are likely to flourish, depending on the requirements of different types of user.

Battery-powered electric vehicles (BEVs) are gradually displacing the internal combustion engine in the move toward greener forms of transportation. An alternative is the hydrogen vehicle, or fuel cell electric vehicle (FCEV). Both are propelled by electric motors, but where the BEV is powered by a lithium ion battery, the FCEV uses a fuel cell to convert hydrogen into electricity.

It’s common to see the two technologies pitted against one another as alternatives. The major point of contention is whether hydrogen is as green as its supporters like to argue. That’s because while hydrogen vehicles emit no emissions, the process by which hydrogen is extracted and compressed into fuel tanks results in greater efficiency losses. Volkswagen has been quite public in asserting that this makes the BEV the clear winner.

However, there are other leading manufacturers, notably Toyota, Honda and Hyundai, who are clearly prioritising FCEVs. Companies investing in this technology are betting that hydrogen will likely play a much bigger role in our energy needs in general in the decades to come. There are also greener methods of extraction being developed, such as obtaining hydrogen from biomass.

Another key area of comparison is cost. Here, the BEV appears to have the upper hand for now. That’s partly because FCEVs are not being manufactured on a large enough scale yet. However, a recent report from Ballard and Deloitte China concludes that FCEVs will be cheaper to run than BEVs within a decade.

The FCEV boasts great benefits in areas where BEVs typically struggle. A major drawback of the battery-powered electric vehicle is range anxiety — fears the vehicle won’t travel far enough on a single charge. Because the energy in a fuel cell is much more densely packed, these vehicles can offer much better range without the need to refuel.

The FCEV also offers superior charging times. A major drawback for BEVs is the excessive charging time, with vehicles often taking hours to fully charge despite shorter ranges. In contrast, a hydrogen vehicle can be fuelled in roughly the same time it would take to add fuel to your traditional diesel or petrol vehicle.

These factors matter more for some vehicles than for others. At Pailton Engineering, we provide bespoke steering system solutions to a range of different vehicle manufacturers. Speaking from the perspective of someone who works closely with bus manufacturers and commercial vehicle manufacturers, the current debate between advocates of BEVs and FCEVs is too heavily skewed in favour of passenger cars.

Range anxiety and charging time are problematic for all of us, but if you have a fleet of heavy goods vehicles travelling long distances, the benefits of longer ranges are more apparent. To help alleviate range anxiety for these large vehicles, lightweighting is a big trend in zero-emission vehicle manufacturing, as less weight requires less energy to haul it.

Similarly, if you’re aiming to replace a fleet of diesel-powered buses with a green alternative, the fact that hydrogen-powered buses take so much less time to charge is an obvious selling point.

By asking which of these two technologies is superior, we risk falling into the trap of always seeing them in competition. That need not be the case. The answer will depend on which sector we’re talking about and the specific needs of any given vehicle manufacturer. If there was room for petrol and diesel, then why not electric and hydrogen?

It’s impossible to predict precisely what percentage of our transportation fleet will be accounted for by hydrogen vehicles by 2050. In the medium term, BEVs are likely to maintain their lead over their hydrogen equivalents in the automobile market. In other sectors, however, the picture is quite different. Both technologies are good bets. For manufacturers of buses, trucks and commercial vehicles, it will be important to recognise that both batteries and hydrogen fuel cells will probably play an important part in our greener future.

NextEra Energy to Build Its First Green Hydrogen Plant in Florida

Florida_Beach_Coast_XL_Shutterstock_721_420_80_s_c1The emerging green hydrogen market could open new opportunities for NextEra to use its renewable power.


Largest U.S. renewables generator “really excited” about green hydrogen, reveals plans for $65 million pilot plant for Florida Power & Light.

NextEra Energy is closing its last coal-fired power unit and investing in its first green hydrogen facility.

Through its Florida Power & Light utility, NextEra will propose a $65 million pilot in the Sunshine State that will use a 20-megawatt electrolyzer to produce 100 percent green hydrogen from solar power, the company revealed on Friday.

The project, which could be online by 2023 if it receives approval from state regulators, would represent the first step into green hydrogen for NextEra Energy, by far the largest developer and operator of wind, solar and battery plants in North America.

“We’re really excited about hydrogen, in particular when we think about getting not to a net-zero emissions profile but actually to a zero-emissions carbon profile,” NextEra Energy CFO Rebecca Kujawa said on Friday’s earnings call.

“When we looked at this five or 10 years ago and thought about what it would take to get to true zero emissions, we were worried it was extraordinarily expensive for customers,” Kujawa said.

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“What makes us really excited about hydrogen — particularly in the 2030 and beyond timeframe — is the potential to supplement a significant deployment of renewables [and energy storage]. That last amount of emissions you’d take out of the system to get down to zero could be most economically served by hydrogen.”

Green hydrogen plans taking off around the world

Although still in its infancy as a market, the concept of green hydrogen is rapidly catching on globally as a potentially viable way to fully decarbonize energy systems, taking them beyond where simple renewable power generation alone can go even at very high penetrations.

The green hydrogen produced by Florida Power & Light’s electrolyzers would be used to replace a portion of the natural gas that’s consumed by the turbines at FPL’s existing 1.75-gigawatt Okeechobee gas-fired plant, Kujawa said. The electricity will come from solar power that would otherwise have been “clipped,” or gone unused.

If the hydrogen economy scales up and green hydrogen becomes economic, Florida Power & Light would likely retrofit some of its gas facilities to run wholly or partially on hydrogen, Kujawa said.

Most of the vast quantities of hydrogen produced globally today use fossil fuels as a feedstock, generating substantial emissions in the process. In contrast, green hydrogen is made using renewables to power the electrolysis of water, throwing off no CO2 emissions.

Whichever way it’s produced, hydrogen can be used for a variety of purposes, from swapping in for natural gas in thermal power plants to powering fuel cells used to move cars and ships. (For more background, read GTM’s green hydrogen explainer.)

The EU recently set a target of installing 40 gigawatts of electrolyzers within its borders by 2030 to produce green hydrogen, as it charts a path to net-zero.

Air Products, the world’s leading hydrogen producer, recently announced a massive green hydrogen plant to be built in Saudi Arabia, powered by 4 gigawatts of wind and solar. And last week California-based fuel-cell maker Bloom Energy sent its shares soaring by announcing its launch into the commercial hydrogen market.

For NextEra, hydrogen represents not only an opportunity to help decarbonize its FPL utility but also a potential new market for the wind and solar power it generates across North America.

NextEra will start with the same “toe in the water” approach it took with solar and batteries, Kujawa said. “While the investments are expected to be small in the context of our overall capital program, we are excited about the technology’s long-term potential, which should further support future demand for low-cost renewables as well as accelerating the decarbonization of transportation fuel and industrial feedstocks.”

Florida Power & Light’s push into green hydrogen comes just weeks after the utility announced it plans to exit its 847-megawatt portion of Georgia’s Plant Scherer, the largest operating coal-fired power plant in the U.S. — and the last remaining coal unit in NextEra’s portfolio.

CEO Robo’s thoughts on the election

NextEra CEO Jim Robo was asked on the earnings call what impact could come from November’s election, with Joe Biden pledging to push policies aimed at fully decarbonizing the U.S. power supply by 2035 and the Democratic platform promising a near-term surge of renewables.

NextEra will be “positioned really well regardless of who wins in November,” Robo said.

“You can remember back close to four years ago … there was some turmoil around our stock when President Trump was elected. We’ve managed to completely be fine under this administration in terms of being able to continue to grow our renewable business, because you know: it’s all about economics.”

“The time for renewables is now and that kind of transcends politics, frankly,” Robo said. “Obviously, we watch [political outcomes] closely. We think good clean energy policy is important and the right policy for America in the future.”

Waterloo Institute for Nanotechnology working to spray away COVID


What if you could spray away COVID-19?

That’s the idea behind an anti-viral surface coating being developed in a collaborative project between by researchers at The Waterloo Institute for Nanotechnology (WIN) within the University of Waterloo and SiO2 Innovation Labs.

The coating will kill the COVID-19 virus immediately upon contact with any surface.

According to Dr. Sushanta Mitra, Professor of Mechanical and Mechatronics Engineering and lead researcher on the project.

“The COVID-19 virus can survive on surfaces for 24 hours or more. In order to protect front-line workers and the general public, it’s important that the virus be neutralized immediately when it comes into contact with any surface. Our work will culminate in the production of an anti-viral coating that will do just that.”

                                                                     Dr. Sushanta Mitra


This research is multi-faceted and is being conducted by many different researchers at Waterloo, including chemical engineering professor Boxin Zhao and chemistry professor  John Honek.

In a recent interview, Mitra said he thinks it will be six or seven months before preparations can be made to bring the product to market and he notes the huge advantages of working with SiO2 Innovation Labs, whose commercial and industrial coatings are made here.

“They already make materials to kill pathogens such as e-coli, they make anti-bacterial and anti-microbial coatings … We want the product to be made in Canada to help Canadians fight COVID, and hopefully make it available to the global community,” said Mitra.

In a release from SiO2 Innovation Labs, CTO Bruce Johnston said: “We’re thrilled to be collaborating with Professor Mitra and WIN in order to bring to market a surface coating that can neutralize pathogens quickly and their subsequent spread. Reduced infection rates will save lives and create safer environments in public and private spaces including homes, the work place, schools, stores, public transit and hospitality venues.

“Our history of creating and delivering safe, sustainable and environmentally friendly products is enabling us to meet this historic moment.”

Mitra’s research involves droplet transmission, viral load and interaction with various surfaces. The coating being developed will prevent droplet adherence even as it destroys the virus’ envelope — the lipid membrane — “because when you destroy that, you destroy the virus.”

Most of us learned about the virus ‘envelope’ from the information about the importance of hand-washing, soap being a surfactant.

The plan will be for the anti-COVID-19 material to be available in different forms, as a coating and also in spray or dip coat format.

Health workers can spray it on personal protective equipment (PPE) to repel (and destroy) viral droplets from masks or gowns; the coating can be used on door handles and high touch surfaces and floors.

“Once the economy is reopened and people go back to work, you’ll need this kind of coating,” said Mitra. “Clearing surfaces all the time is labour-intensive, but the coating lasts a long time.”

Do they have much competition for this product from other scientists?

“There are others working on similar products, and that’s good. There are eight billion people on this planet and we can’t meet the entire demand.”

As regards COVID-19, Mitra said: “The global effort is critical. We learn from each other, and that includes on a vaccine. We are all working to push as much knowledge as possible into the public domain.”

Mitra reminds us that The Waterloo Institute for Nanotechnology — which is Canada’s largest nanotechnology institute — is committed to UN Sustainable Development Goals.

“And one of the stated goals of the United Nations is good health for everyone,” he said. “This is our small effort in that direction.”

MIT: Lighting the Way to Better Battery Technology

MIT New Battery 0720 Supratim_Das_9Supratim Das is determined to demystify lithium-ion batteries, by first understanding their flaws.  Photo: Lillie Paquette/School of Engineering

Doctoral candidate Supratim Das wants the world to know how to make longer-lasting batteries that charge mobile phones and electric cars.

Supratim Das’s quest for the perfect battery began in the dark. Growing up in Kolkata, India, Das saw that a ready supply of electric power was a luxury his family didn’t have. “I wanted to do something about it,” Das says. Now a fourth-year PhD candidate in MIT chemical engineering who’s months away from defending his thesis, he’s been investigating what causes the batteries that power the world’s mobile phones and electric cars to deteriorate over time.

Lithium-ion batteries, so-named for the movement of lithium ions that make them work, power most rechargeable devices today. The element lithium has properties that allow lithium-ion batteries to be both portable and powerful; the 2019 Nobel Prize in Chemistry was awarded to scientists who helped develop them in the late 1970s. But despite their widespread use, lithium-ion batteries, essentially a black box during operation, harbor mysteries that prevent scientists from unlocking their full potential. Das is determined to demystify them, by first understanding their flaws.

In principle, rechargeable batteries shouldn’t expire. In practice, however, they can only be recharged a finite number of times before they lose their ability to hold a charge. An ordinary battery eventually stops working when the terminals of the battery — called electrodes — are permanently altered by the ions passing from one terminal of the battery to the other. In a rechargeable battery, the electrodes recover when an external charger sends those ions back where they came from.

Lithium ion batteries work the same way. Typically, one electrode is made of graphite, and the other of lithium compounds with transition metals such as iron, cobalt, or nickel. At the lithium electrode, lithium atoms part ways with their electrons, swim through the battery fluid (electrolyte), and wait at the other electrode. Meanwhile, the electrons take the long way around. They flow out the battery, through a device that needs the power, and into the second electrode, where they rejoin the lithium ions. When a mobile phone is plugged in to be charged, the ions and electrons retrace their steps, and the battery can be used again.

When a battery is charged, however, not all the lithium ions make it back. Every charging cycle leaves ions straggling at the graphite electrode, and the battery loses capacity over time. Das found this perplexing, because it meant that draining a phone’s battery didn’t harm it, but recharging it did. He addressed this conundrum in a couple of open-access academic publications in 2019.

There was also another problem. When a battery is “fast-charged” — a feature that comes with many of the latest electronics — lithium ions start layering (plating) over the carbon electrode, instead of transporting (intercalating) into the material. Prolonged lithium plating can cause uncontrolled growth of fractal-like dendrites. This can cause short-circuiting, even fires.

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In his doctoral research, Das and collaborators have been able to understand the microscopic changes that degrade a battery’s electrodes over its lifetime, and develop multiscale physics-based models to predict them in a robust manner at the macro-scale.

Such multiscale models can aid battery manufacturers to substantially reduce battery health diagnostics costs before it is incorporated into a device, and make batteries safer for consumers. In his latest project, he’s using that knowledge to investigate the best way of charging a lithium-ion battery without damaging it. Das hopes his contributions help scientists achieve further breakthroughs in battery science and make batteries safer, especially when the latest technology is often closely guarded by private companies. “What our group is trying to do is improve the quality of open access academic literature,” Das says. “So that when other people are trying to start their research in batteries, they don’t have to start at the theory from five to 10 years ago.”

Das is well-placed to walk between the worlds of academia and industry.

As an undergraduate in Indian Institute of Technology (IIT) Delhi, Das learned that chemical engineers could use equations and experiments to invent technology like drugs and semi-conductors. “Just the fact that here I was in college, learning something that gave me the power to potentially impact the lives of N number of people in a positive manner, was utterly fascinating to me,” Das says. He also interned at a consumer goods company, where he realized that academia would allow him more freedom to pursue ambitious ideas.

In his sophomore year, Das wrote to a professor at the Hong Kong University of Science and Technology, seeking an opportunity to do research. He flew out that summer, and spent weeks learning about high-power lithium-ion batteries. “It was an eye-opening experience,” Das recalls. He returned to his coursework, but the idea of working on batteries had taken hold. “I never thought that something I can do with my own hands can potentially make impact at the scale that battery technology does,” Das says. He continued working on research projects and made key contributions in the field of multiphase chemical reaction engineering during his undergraduate degree, and eventually wound up applying to the graduate program at MIT.

In his second year of graduate work, Das spent a semester as a technical consultant for Shell in Houston, Texas and Emirates Global Aluminum in Dubai. There, he learned lessons that would prove invaluable in his graduate work. “It taught me problem formulation,” Das says. “Identifying what is relevant for stakeholders; what to work on so as to best use the team’s skill sets; how to distribute your time.”

After Das’s experience in the field, he discovered that as a scientist he could share valuable knowledge about battery research and the future of the technology with energy economists. He also realized that policymakers considered their own criteria when investing in technology for the future.

Das believed that such a perspective would help him inform policy decisions as a scientist, so he decided that after completing his PhD, he would pursue an MBA focusing on energy economics and policy at MIT’s Sloan School of Management. “It will allow me to contribute more to society if I’m able to act as a bridge between someone who understands the hardcore, microscopic physics of a battery, and someone who understands the economic and policy implications of introducing that battery into a vehicle or a grid,” Das says.

Das believes that the program, which begins next fall, will allow him to work with other energy experts who bring their own knowledge and skills to the table. He understands the power of collaboration well: at college, Das was elected president of a dorm of 450-plus residents and worked with students and administration to introduce new facilities and events on campus. After arriving in Cambridge, Massachusetts, Das helped other students manage Ashdown House, represented chemical engineering students on the Graduate Student Advisory Board, and served in the leadership team for the MIT Energy Club, spearheading the organization of MIT EnergyHack 2019.

He also launched a community service initiative within the Department of Chemical Engineering; once a week, students mentor school children and volunteer at nonprofits in Cambridge. He was able to attract funding for his initiative and was awarded by the department for successfully mobilizing 80-plus students in the community within the span of a year. “I’m constantly surprised at what we can achieve when we work with other people,” Das says.

After all, other people have helped Das make it this far. “I owe a lot of success to a number of sacrifices my mom made for me, including giving up her own career,” he says. At MIT, he feels fortunate to have met mentors like his advisor, Martin Bazant, and Practice School directors Robert Fisher and Brian Stutts, and the many colleagues who have offered answers to his questions. “Here, I’ve discovered what it means to synergize with really smart people who are really passionate — and really nice at the same time,” Das says. “Grateful is the one word I’d use.”

Buzzing to rebuild broken bone

Buzzing a broken bone bonefracture

Healing broken bones could get easier with a device that provides both a scaffold for the bone to grow on and electrical stimulation to urge it forward, UConn engineers reported on June 27 in the Journal of Nano Energy.

Although minor bone breaks usually heal on their own, large fractures with shattered or missing chunks of bone are more difficult to repair. Applying a tiny electrical field to the site of the fracture to mimic the body’s natural electrical field helps the cells regenerate. But the  that do this are usually bulky, rely on electrical wires or toxic batteries, require invasive removal surgery, and can’t do much for serious injuries.

Now, a group of biomedical engineers from UConn have developed a  of non-toxic polymer that also generates a controllable electrical field to encourage bone growth. The scaffold helps the body bridge large fractures. Although many scientists are exploring the use of scaffolding to encourage bone growth, pairing it with  is new.

The team demonstrated the device in mice with skull .

The  the scaffold generates is very small, just a few millivolts. And uniquely for this type of device, the voltage is generated via remotely-controlled ultrasound. The ultrasound vibrates the polymer scaffolding, which then creates an electrical field (materials that create electricity from vibration, or vice versa, are called piezoelectric.) To help heal a thigh fracture, for example, the polymer scaffold can be implanted across the broken bone. Later, the person with the broken bone can wave the ultrasound wand over their own thigh themselves. No need for batteries, and no need for invasive removal surgery once the bone is healed.

“The  relates to the natural signal generated by your body at the injury location. We can sustain that voltage, on demand and reversible,” for however long is needed using ultrasound, says UConn biomedical engineer Thanh Nguyen. The piezoelectric polymer Nguyen and his colleagues use to build the scaffold is called poly(L-lactic acid), or PLLA. In addition to being non-toxic and piezoelectric, PLLA gradually dissolves in the body over time, disappearing as the new bone grows.

“The electric field created by the piezoelectric PLLA scaffold seems to attract bone cells to the site of the fracture and promote stem cells to evolve into bone cells. This technology can possibly be combined with other factors to facilitate regeneration of other tissues, like cartilage, muscles or nerves,” says Ritopa Das, a  in Nguyen group and the first author of the published paper.

Currently Nguyen and his colleagues are working to make the polymer more favorable to bone growth, so that it heals a large fracture more quickly. They are also trying to understand why electrical fields encourage bone growth at all. Bone itself is somewhat piezoelectric, generating a surface charge when the bone is stressed by everyday life activities. That surface charge encourages more bone to grow. But scientists don’t know whether it’s because it helps cells stick to the surface of the , or whether it makes the cells themselves more active.

“Once we understand the mechanism, we can devise a better way to improve the material and the whole approach of tissue stimulation,” Nguyen says.

Explore further

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Spinal Cord Stimulation Therapy for Chronic Pain from Boston Scientific 

EU’s Exploding Demand for Anode Materials for Lithium-Ion Batteries Creates Opportunity for Australia’s Talga Resources to Capture Significant Market Share as a Local ‘Non-Asia’ Source Provider

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Posted By Graphene Council, Friday, June 26, 2020

Overwhelming European demand sees Australia’s battery anode company Talga Resources plan for expanded output at its new Swedish battery anode factory.

Expressions of interest received for Talga’s lithium-ion battery anode products exceed 300% of planned annual capacity of the Vittangi Anode Project, the company says.

Talnode products are now in 36 active commercial engagements covering the majority of planned European li-ion battery manufacturers and six major global automotive OEMs.

Talga says it’s expanding the scale of the Niska scoping study for the Vittangi Project to review larger anode production options as a result of this significant interest.

Li-ion battery megafactories are set to require more than 2.5 million tonnes per annum (tpa) active anode material by 2029, up from about 450,000 tpa anode production today, with Europe the fastest growing market.

That’s because worldwide li-ion battery demand continues to rapidly increase, with global battery manufacturing capacity set to exceed 2.5 tera-Watt hours (TWh) per annum by 2029 across 142 battery plants.

“Our engagement with European battery companies and automotive OEMs has grown rapidly, with customers attracted by the potential of locally produced anode at competitive costs and with world-leading sustainability,” Talga managing director Mark Thompson says.

Graphene Anode Mark-Thompson-Talga-Resource

”As we progress Talnode-C through commercial qualification stages with customers it is pleasing to note that interest now greatly exceeds our original planned production, and that the need to review expansion options has arisen this early.”

The increased interest means the company is targeting completion of the Niska scoping study in Q3 2020.

While COVID-19 has severely impacted EV sales in the short term, Bloomberg New Energy Finance data shows EV sales hold up better than internal combustion engine (ICE) vehicles due to new (lower cost) models and supportive government policies.

In the quarters prior to the COVID-19 outbreak, EV sales as a percentage of total passenger vehicles rose rapidly in the EU, with Germany and France recording increases of 100% during the period.

Numerous countries across Europe have implemented some form of financial incentives towards customer uptake of EVs, and post COVID-19 these have increased markedly in some countries.

Talga is entering the European market at a time when 100% of anode supply is still sourced from Asia. The company’s marketing team reports that, post COVID-19, localisation is becoming an increasingly significant factor influencing customer’s purchasing decisions.

NC State University has developed a Flexible Carbon Nanotube Film with a unique combination of thermal, electrical and physical properties that make it an an Excellent Candidate for Next-Generation of Smart Fabrics

Carbon NTs that Heat and Cool id55557_1

Researchers reported in a new study that a material made of carbon nanotubes may be key in developing clothing that can heat or cool the wearer on demand. The film is twisted into a filament yarn and wound around a tube to show its flexibility. (Image: Kony Chatterjee)

A film made of carbon nanotubes (CNT) may be a key material in developing clothing that can heat or cool the wearer on demand. A new North Carolina State University study finds that the CNT film has a combination of thermal, electrical and physical properties that make it an appealing candidate for next-generation smart fabrics.

The researchers were also able to optimize the thermal and electrical properties of the material, allowing the material to retain its desirable properties even when exposed to air for many weeks. Moreover, these properties were achieved using processes that were relatively simple and did not need excessively high temperatures.
“Many researchers are trying to develop a material that is non-toxic and inexpensive, but at the same time is efficient at heating and cooling,” said Tushar Ghosh, co-corresponding author of the study (ACS Applied Energy Materials“In-plane Thermoelectric Properties of Flexible and Room Temperature Processable Doped Carbon Nanotube Films”). “Carbon nanotubes, if used appropriately, are safe, and we are using a form that happens to be inexpensive, relatively speaking. So it’s potentially a more affordable thermoelectric material that could be used next to the skin.” Ghosh is the William A. Klopman Distinguished Professor of Textiles in NC State’s Wilson College of Textiles.
“We want to integrate this material into the fabric itself,” said Kony Chatterjee, first author of the study and a Ph.D. student at NC State. “Right now, the research into clothing that can regulate temperature focuses heavily on integrating rigid materials into fabrics, and commercial wearable thermoelectric devices on the market aren’t flexible either.”
To cool the wearer, Chatterjee said, CNTs have properties that would allow heat to be drawn away from the body when an external source of current is applied.
“Think of it like a film, with cooling properties on one side of it and heating on the other,” Ghosh said.
The researchers measured the material’s ability to conduct electricity, as well as its thermal conductivity, or how easily heat passes through the material.
One of the biggest findings was that the material has relatively low thermal conductivity – meaning heat would not travel back to the wearer easily after leaving the body in order to cool it. That also means that if the material were used to warm the wearer, the heat would travel with a current toward the body, and not pass back out to the atmosphere.
The researchers were able to accurately measure the material’s thermal conductivity through a collaboration with the lab of Jun Liu, an assistant professor of mechanical and aerospace engineering at NC State. The researchers used a special experimental design to more accurately measure the material’s thermal conductivity in the direction that the electric current is moving within the material.
“You have to measure each property in the same direction to give you a reasonable estimate of the material’s capabilities,” said Liu, co-corresponding author of the study. “This was not an easy task; it was very challenging, but we developed a method to measure this, especially for thin flexible films.”
The research team also measured the ability of the material to generate electricity using a difference in temperature, or thermal gradient, between two environments. Researchers said that they could take advantage of this for heating, cooling, or to power small electronics.
Liu said that while these thermoelectric properties were important, it was also key that they found a material that was also flexible, stable in air, and relatively simple to make.
“The point of this paper isn’t that we achieved the best thermoelectric performance,” Liu said. “We achieved something that can be used as a flexible, electronic, soft material that’s easy to fabricate. It’s easy to prepare this material, and easy to achieve these properties.”
Ultimately, their vision for the project is to design a smart fabric that can heat and cool the wearer, along with energy harvesting. They believe that a smart garment could help reduce energy consumption.
“Instead of heating or cooling a whole dwelling or space, you would heat or cool the personal space around the body,” Ghosh said. “If we could get the thermostat down a degree or two, that could save a tremendous amount of energy.”
Source: North Carolina State University
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