The Defense Advanced Research Projects Agency (DARPA) is reportedly interested in a new wirelessly-connected contact lens recently unveiled in France, the latest in the agency’s ongoing search for small-scale technology to augment U.S. service members’ visual capabilities in the field.
Researchers at leading French engineering IMT Atlantique in mid-April announced “the first autonomous contact lens incorporating a flexible micro-battery,” a lightweight lens capable of not only providing augmented vision assistance to users but relaying visual information wirelessly — not unlike, say, the lens Jeremy Renner uses in Mission: Impossible – Ghost Protocol to scan a batch of nuclear codes: (Watch)
More importantly, the new lens can perform its functions without a bulky external power supply, capable of “continuously supply[ing] a light source such as a light-emitting diode (LED) for several hours,” according to the IMT Atlantique announcement.
“Storing energy on small scales is a real challenge,” said Thierry Djenizian, head of the Flexible Electronics Department at the Centre Microélectronique de Provence Georges Charpak and co-head of the p
The lens was primarily designed for medical and automotive applications, but according to French business magazine L’Usine Nouvelle (‘The New Factory’), the lens has garnered interest from both DARPA and Microsoft, which was recently contracted by the the U.S. Army to furnish soldiers with with its HoloLens augmented reality headset.
DARPA’s been on the hunt for a high-tech eyepiece more than a decade, and the agency has funded several similar projects in recent years.
In January 2012, DARPA announced that U.S.-based tech firm Innovega was developing “iOptiks” contact lenses designed to enhance normal vision by projecting digital images onto a standard pair of eyeglasses like a miniaturized heads-up display, “allow[ing] a wearer to view virtual and augmented reality images without the need for bulky apparatus,” as the agency put it.
Three years later, researchers at Switzerland’s École Polytechnique Fédérale de Lausanne (EPFL) unveiled a DARPA-funded contact lens that “magnifies objects at the wink of an eye,” The Guardian reported, although researchers concluded that the technology was better suited for age-related visual deterioration rather than battlefield applications.
“[DARPA researchers] were really interested in supervision, but the reality is more tame than that,” researcher Eric Tremblay told the American Association for the Advancement of Science at the time.
These past projects, like most other blue sky research projects pursued by the DARPA, have likely informed the Pentagon’s research and development of augmented reality tech that U.S. military planners have increasingly pursued in recent years. And the technology is only poised to improve: as Wired recently reported, big tech companies like Google, Sony, and Samsung are all pushing the envelope when it comes to consumer-marketxed augmented vision tech.
But when “smart” contact lenses will actually hit Pentagon armories, like most futuristic DARPA efforts, remains to be seen. In the meantime, it looks like U.S. service members in search of enhanced vision will have to stick to their “birth control glasses.”
This article by Jared Keller originally appeared at Task & Purpose. Follow Task & Purpose onTwitter. This article first appeared in 2019.
Scientists have long suspected that the way materials behave on the nanoscale – that is when particles have dimensions of about 1–100 nanometres – is different from how they behave on any other scale. A new paper in the journal Chemical Science provides concrete proof that this is the case.
The laws of thermodynamics govern the behavior of materials in the macro world, while quantum mechanics describes behavior of particles at the other extreme, in the world of single atoms and electrons.
But in the middle, on the order of around 10–100,000 molecules, something different is going on. Because it’s such a tiny scale, the particles have a really big surface-area-to-volume ratio. This means the energetics of what goes on at the surface become very important, much as they do on the atomic scale, where quantum mechanics is often applied.
Classical thermodynamics breaks down. But because there are so many particles, and there are many interactions between them, the quantum model doesn’t quite work either.
And because there are so many particles doing different things at the same time, it’s difficult to simulate all their interactions using a computer. It’s also hard to gather much experimental information, because we haven’t yet developed the capacity to measure behaviour on such a tiny scale.
This conundrum becomes particularly acute when we’re trying to understand crystallisation, the process by which particles, randomly distributed in a solution, can form highly ordered crystal structures, given the right conditions.
Chemists don’t really understand how this works. How do around 1018 molecules, moving around in solution at random, come together to form a micro- to millimetre size ordered crystal? Most remarkable perhaps is the fact that in most cases every crystal is ordered in the same way every time the crystal is formed.
However, it turns out that different conditions can sometimes yield different crystal structures. These are known as polymorphs, and they’re important in many branches of science including medicine – a drug can behave differently in the body depending on which polymorph it’s crystallised in.
What we do know so far about the process, at least according to one widely accepted model, is that particles in solution can come together to form a nucleus, and once a critical mass is reached we see crystal growth. The structure of the nucleus determines the structure of the final crystal, that is, which polymorph we get.
What we have not known until now is what determines the structure of the nucleus in the first place, and that happens on the nanoscale.
In this paper, the authors have used mechanochemistry – that is milling and grinding – to obtain nanosized particles, small enough that surface effects become significant. In other words, the chemistry of the nanoworld – which structures are the most stable at this scale, and what conditions affect their stability, has been studied for the first time with carefully controlled experiments.
And by changing the milling conditions, for example by adding a small amount of solvent, the authors have been able to control which polymorph is the most stable. Professor Jeremy Sanders of the University of Cambridge’s Department of Chemistry, who led the work, said “It is exciting that these simple experiments, when carried out with great care, can unexpectedly open a new door to understanding the fundamental question of how surface effects can control the stability of nanocrystals.”
Joel Bernstein, Global Distinguished Professor of Chemistry at NYU Abu Dhabi, and an expert in crystal growth and structure, explains: “The authors have elegantly shown how to experimentally measure and simulate situations where you have two possible nuclei, say A and B, and determine that A is more stable. And they can also show what conditions are necessary in order for these stabilities to invert, and for B to become more stable than A.”
“This is really news, because you can’t make those predictions using classical thermodynamics, and nor is this the quantum effect. But by doing these experiments, the authors have started to gain an understanding of how things do behave on this size regime, and how we can predict and thus control it. The elegant part of the experiment is that they have been able to nucleate A and B selectively and reversibly.”
One of the key words of chemical synthesis is ‘control’. Chemists are always trying to control the properties of materials, whether that’s to make a better dye or plastic, or a drug that’s more effective in the body. So if we can learn to control how molecules in a solution come together to form solids, we can gain a great deal. This work is a significant first step in gaining that control.
More information: A. M. Belenguer et al. Solvation and surface effects on polymorph stabilities at the nanoscale, Chem. Sci. (2016). DOI: 10.1039/C6SC03457H
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The batteries that power our high-tech lifestyle are built using materials extracted in dirty, often life-threatening conditions.
If you have a cell phone, laptop, a hybrid car, or an electric vehicle, you may want to sit down. This may hurt.
You have probably heard of blood diamonds and conflict minerals. Maybe you’ve even read up a bit on how big consumer tech companies are trying (and, in some cases, being forced by governments) to sort out where the materials that go into their gadgets come from. But stories about “supply chains,” “globalization,” and “poor working conditions” can seem a world away, or just plain academic.
In a sweeping, heartbreaking series, the Washington Post is making sure it hits home.
Take the example of Yu Yuan, a farmer who lives near a graphite factory in northeastern China. In a video, he swipes at shimmering grime accumulated in his window sill and points at a barren cornfield.
The crops turn black with graphite dust he says, and don’t grow properly. He and his wife worry about the air they’re breathing and their water is undrinkable, polluted by chemicals dumped from the graphite plant. “There is nothing here once the factory is done damaging this place,” he says.
Workers in Lubumbashi, Democratic Republic of the Congo, tend to an oven that processes slag from the region’s cobalt and copper-rich ores.
Over two pieces so far, the Post has traced the path of first cobalt and then graphite as they make their way from mines to factories and ultimately into our hands as the cathodes and anodes, respectively, for lithium-ion batteries.
Each story is a remarkable blend of globe-spanning investigative journalism, business reporting, and an appeal to us to confront the consequences of owning the devices that power our high-tech lifestyles.
While graphite is mined and processed mostly in China, a huge amount of cobalt comes from mines in the Democratic Republic of the Congo, where “artisanal” miners sometimes dig through the floor of their own houses in search of ore. Mines collapse frequently. Injuries and death are commonplace.
Once extracted, the materials end up in Asia, where companies you’ve probably never heard of turn them into battery parts. The largest battery makers in the world, including Samsung SDI, LG Chem, and Panasonic, then purchase the components and turn them into batteries that go into phones, computers, and cars. (article continued below)
A “New Way” to Power Our World?
Read (Watch the YouTube Video) About a New Energy Storage Company ~ Making Energy Dense, Flexible Form, Rapid Charge/ Re-Charge Super Capacitors and Batteries for Medical Devices, Drone Batteries, Power Banks, Motorcycle and EV Batteries, developed from a Rice University Technology using ‘Nanoporous Nickle’ and ‘Si Nano Wires.’
(article continued) Lithium batteries are prized for being light and having a high energy density compared to other battery chemistries. The modern smartphone would be difficult to imagine without a lithium battery as its power supply. They help power hybrid cars, and the small but fast-growing fleet of all-electric vehicles wouldn’t exist without them.
Interest in electric cars, in particular, is fueled by claims that the vehicles are clean and good for the environment. That may be true in the countries where they are mostly sold. But when we consider the bigger picture, the reality is something else altogether.
Read More: MIT Review – August 2016
Startups with novel chemistries tend to falter before they reach full production.
Earlier this year, Ellen Williams, the director of ARPA-E, the U.S. Department of Energy’s advanced research program for alternative energy, made headlines when she told the Guardiannewspaper that “We have reached some holy grails in batteries.”
Despite very promising results from the 75-odd energy-storage research projects that ARPA-E funds, however, the grail of compact, low-cost energy storage remains elusive.
A number of startups are closer to producing devices that are economical, safe, compact, and energy-dense enough to store energy at a cost of less than $100 a kilowatt-hour. Energy storage at that price would have a galvanic effect, overcoming the problem of powering a 24/7 grid with renewable energy that’s available only when the wind blows or the sun shines, and making electric vehicles lighter and less expensive.
But those batteries are not being commercialized at anywhere near the pace needed to hasten the shift from fossil fuels to renewables. Even Tesla CEO Elon Musk, hardly one to underplay the promise of new technology, has been forced to admit that, for now, the electric-car maker is engaged in a gradual slog of enhancements to its existing lithium-ion batteries, not a big leap forward.
In fact, many researchers believe energy storage will have to take an entirely new chemistry and new physical form, beyond the lithium-ion batteries that over the last decade have shoved aside competing technologies in consumer electronics, electric vehicles, and grid-scale storage systems. In May the DOE held a symposium entitled “Beyond Lithium-Ion.” The fact that it was the ninth annual edition of the event underscored the technological challenges of making that step.
Qichao Hu, the founder of SolidEnergy Systems, has developed a lithium-metal battery (which has a metallic anode, rather than the graphite material used for the anode in traditional lithium-ion batteries) that offers dramatically improved energy density over today’s devices (see “Better Lithium Batteries to Get a Test Flight”). The decade-long process of developing the new system highlighted one of the main hurdles in battery advancement: “In terms of moving from an idea to a product,” says Hu, “it’s hard for batteries, because when you improve one aspect, you compromise other aspects.”
Added to this is the fact that energy storage research has a multiplicity problem: there are so many technologies, from foam batteries to flow batteries to exotic chemistries, that no one clear winner is attracting most of the funding and research activity.
According to a recent analysis of more than $4 billion in investments in energy storage by Lux Research, startups developing “next-generation” batteries—i.e., beyond lithium-ion—averaged just $40 million in funding over eight years. Tesla’s investment in its Gigafactory, which will produce lithium-ion batteries, will total around $5 billion. That huge investment gap is hard to overcome.
“It will cost you $500 million to set up a small manufacturing line and do all the minutiae of research you need to do to make the product,” says Gerd Ceder, a professor of materials science at the University of California, Berkeley, who heads a research group investigating novel battery chemistries. Automakers, he points out, may test new battery systems for years before making a purchase decision. It’s hard to invest $500 million in manufacturing when your company has $5 million in funding a year.
Even if new battery makers manage to bring novel technologies to market, they face a dangerous period of ramping up production and finding buyers. Both Leyden Energy and A123 Systems failed after developing promising new systems, as their cash needs climbed and demand failed to meet expectations. Two other startups, Seeo and Sakti3, were acquired before they reached mass production and significant revenues, for prices below what their early-stage investors probably expected.
Meanwhile, the Big Three battery producers, Samsung, LG, and Panasonic, are less interested in new chemistries and radical departures in battery technology than they are in gradual improvements to their existing products. And innovative battery startups face one major problem they don’t like to mention: lithium-ion batteries, first developed in the late 1970s, keep getting better.
IMAGE: IMAGE SHOWS MAGNETIC NANORODS IN THE VIAL ATTRACTED TO THE MAGNET. GEORGIA TECH RESEARCHERS HAVE DEVELOPED A NEW STRATEGY FOR CRAFTING ONE-DIMENSIONAL NANORODS BASED ON CELLULOSE USING A WIDE RANGE… view more
CREDIT: CREDIT: ROB FELT, GEORGIA TECH
GEORGIA INSTITUTE OF TECHNOLOGY
Materials scientists have developed a new strategy for crafting one-dimensional nanorods from a wide range of precursor materials. Based on a cellulose backbone, the system relies on the growth of block copolymer “arms” that help create a compartment to serve as a nanometer-scale chemical reactor. The outer blocks of the arms prevent aggregation of the nanorods.
The produced structures resemble tiny bottlebrushes with polymer “hairs” on the nanorod surface. The nanorods range in size from a few hundred nanometers to a few micrometers in length, and a few tens of nanometers in diameter. This new technique enables tight control over diameter, length and surface properties of the nanorods, whose optical, electrical, magnetic and catalytic properties depend on the precursor materials used and the dimensions of the nanorods.
The nanorods could have applications in such areas as electronics, sensory devices, energy conversion and storage, drug delivery, and cancer treatment. Using their technique, the researchers have so far fabricated uniform metallic, ferroelectric, upconversion, semiconducting and thermoelectric nanocrystals, as well as combinations thereof. The research, supported by Air Force Office of Scientific Research, will be reported on September 16 in the journal Science.
“We have developed a very general and robust strategy to craft a rich variety of nanorods with precisely-controlled dimensions, compositions, architectures and surface chemistries,” said Zhiqun Lin, a professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. “To create these structures, we used nonlinear bottlebrush-like block copolymers as tiny reactors to template the growth of an exciting variety of inorganic nanorods.”
Nanorod structures aren’t new, but the technique used by Lin’s lab produces nanorods of uniform sizes – such as barium titanate and iron oxide, which have not yet been demonstrated via wet-chemistry approaches in the literature – and highly-uniform core-shell nanorods made by combining two dissimilar materials. Lin and former postdoctoral research associate Xinchang Pang say the precursor materials applicable to the technique are virtually limitless.
“There are many precursors of different materials available that can be used with this robust system,” Lin said. “By choosing a different outer block in the bottlebrush-like block copolymers, our nanorods can be dissolved and uniformly dispersed in organic solvents such as toluene or chloroform, or in water.”
Fabrication of the nanorods begins with the functionalization of individual lengths of cellulose, an inexpensive long-chain biopolymer harvested from trees. Each unit of cellulose has three hydroxyl groups, which are chemically modified with a bromine atom. The brominated cellulose then serves as macroinitiator for the growth of the block copolymer arms with well-controlled lengths using the atom transfer radical polymerization (ATRP) process, with, for example, poly(acrylic acid)-block-polystyrene (PAA-b-PS) yielding cellulose densely grafted with PAA-b-PS (i.e., cellulose-g-[PAA-b-PS]) that give the bottlebrush appearance.
The next step involves the preferential partitioning of precursors in the inner PAA compartment that serves as a nanoreactor to initiate the nucleation and growth of nanorods. The densely grafted block copolymer arms, together with the rigid cellulose backbone, give researchers the ability to not only prevent aggregation of the resulting nanorods, but also to keep them from bending.
“The polymers are like long spaghetti and they want to coil up,” Lin explained. “But they cannot do this in the complex macromolecules we make because with so many block copolymer arms formed, there is no space. This leads to the stretching of the arms, forming a very rigid structure.”
By varying the chemistry and the number of blocks in the arms of the bottlebrush-like block copolymers, Lin and coworkers produced an array of oil-soluble and water-soluble plain nanorods, core-shell nanorods, and hollow nanorods – nanotubes – of different dimensions and compositions.
For example, by using bottlebrush-like triblock copolymers containing densely grafted amphiphilic triblock copolymer arms, the core-shell nanorods can be formed from two different materials. In most cases, a large lattice mismatch between core and shell materials would prevent the formation of high-quality core-shell structures, but the technique overcomes that limitation.
“By using this approach, we can grow the core and shell materials independently in their respective nanoreactors,” Lin said. “This allows us to bypass the requirement for matching the crystal lattices and permits fabrication of a large variety of core-shell structures with different combinations that would otherwise be very challenging to obtain.”
Lin sees many potential applications for the nanorods.
“With a broad range of physical properties – optical, electrical, optoelectronic, catalytic, magnetic, and sensing – that are dependent sensitively on their size and shape as well as their assemblies, the produced nanorods are of both fundamental and practical interest,” Lin said. “Potential applications include optics, electronics, photonics, magnetic technologies, sensory materials and devices, lightweight structural materials, catalysis, drug delivery, and bio-nanotechnology.”
For example, plain gold nanorods of different lengths may allow effective plasmonic absorption in the near-infrared range for use in solar energy conversion with improved harvesting of solar spectrum. The upconversion nanorods can preferentially harvest the IR solar photons, followed by the absorption of emitted high-energy photons to generate extra photocurrent in solar cells. They can also be used for biological labeling because of their low toxicity, chemical stability, and intense luminescence when excited by near-IR radiation, which can penetrate tissue much better than higher energy radiation such as ultraviolet, as is often required with quantum dot labels.
The gold-iron oxide core-shell nanorods may be useful in cancer therapy, with MRI imaging enabled by the iron oxide shell, and local heating created by the photothermal effect on the gold nanorod core killing cancer cells.
In addition to the researchers already mentioned, co-authors included graduate research assistant Yanjie He and postdoctoral researcher Jaehan Jung in Georgia Tech’s School of Materials Science and Engineering.
This research was supported by the Air Force Office of Scientific Research under grant FA9550-16-1-0187. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsor.
CITATION: Xinchang Pang, Yanjie He, Jaehan Jung, Zhiqun Lin, “1D nanocrystals with precisely controlled dimensions, compositions, and architectures,” (Science 2016).
Slate has recently published an online survey “Tell Us What You Think About Nanotechnology” (Follow the link above to take that survey).
Which … got us to thinking. “We” (Team GNT) should have our very own Survey on Nanotechnology with more focus on you … OUR READERS!
With over 5 Years of publication, 132,000+ hits on any average reporting cycle, representing Followers in over 50 Countries, and 10,000 plus Followers across Social Media … we are guessing you just might have some very “illuminating” and valuable thoughts, visions and opinions to share with us!
So … we are asking you to share your comments with us by answering a few questions and also … leaving us any ‘Open Comments’ you would care to leave. We will gather your responses, share the most interesting ones and let you know what others are “thinking and saying” about Nanotechnology.
1. What Area or Application of Nanotechnology do you find most interesting? (Examples: Bio-Med, Cancer Treatment-Diagnosis, Electronics, Energy – Energy Storage, Materials, Sensors, Quantum Computing, etc.) Don’t let our suggestions limit your responses!
2. Which Areas or Applications do you think are most promising right now? In the future? that will dramatically change the World we live in?
3. Are you worried about the ‘safety’ of nanomaterials? On a scale of 1 to 10, 10 being MOST WORRIED. Why?
4. Which Nanotechnology Application or Area of Research interests you the most?
We have provided a ‘Response/ Contact Form’ for you below OR … you can Leave Us a Comment in the Comments Section. We are really looking forward to hearing from ALL of you!
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The secret to making the best energy storage materials is growing them with as much surface area as possible. Like baking, it requires just the right mixture of ingredients prepared in a specific amount and order at just the right temperature to produce a thin sheet of material with the perfect chemical consistency to be useful for storing energy.
A team of researchers from Drexel University, Huazhong University of Science and Technology (HUST) and Tsinghua University recently discovered a way to improve the recipe and make the resulting materials bigger and better and soaking up energy—the secret? Just add salt.
The team’s findings, which were recently published in the journal Nature Communications, show that using salt crystals as a template to grow thin sheets of conductive metal oxides make the materials turn out larger and more chemically pure—which makes them better suited for gathering ions and storing energy.
“The challenge of producing a metal oxide that reaches theoretical performance values is that the methods for making it inherently limit its size and often foul its chemical purity, which makes it fall short of predicted energy storage performance,” said Jun Zhou, a professor at HUST’s Wuhan National Laboratory for Optoelectronics and an author of the research. Our research reveals a way to grow stable oxide sheets with less fouling that are on the order of several hundreds of times larger than the ones that are currently being fabricated.”
In an energy storage device—a battery or a capacitor, for example—energy is contained in the chemical transfer of ions from an electrolyte solution to thin layers of conductive materials. As these devices evolve they’re becoming smaller and capable of holding an electric charge for longer periods of time without needing a recharge. The reason for their improvement is that researchers are fabricating materials that are better equipped, structurally and chemically, for collecting and disbursing ions.
In theory, the best materials for the job should be thin sheets of metal oxides, because their chemical structure and high surface area makes it easy for ions to attach—which is how energy storage occurs. But the metal oxide sheets that have been fabricated in labs thus far have fallen well short of their theoretical capabilities.
According to Zhou, Tang and the team from HUST, the problem lies in the process of making the nanosheets—which involves either a deposition from gas or a chemical etching—often leaves trace chemical residues that contaminate the material and prevent ions from bonding to it. In addition, the materials made in this way are often just a few square micrometers in size.
Using salt crystals as a substrate for growing the crystals lets them spread out and form a larger sheet of oxide material. Think of it like making a waffle by dripping batter into a pan versus pouring it into a big waffle iron; the key to getting a big, sturdy product is getting the solution—be it batter, or chemical compound—to spread evenly over the template and stabilize in a uniform way.
“This method of synthesis, called ‘templating’—where we use a sacrificial material as a substrate for growing a crystal—is used to create a certain shape or structure,” said Yury Gogotsi, PhD, University and Trustee Chair professor in Drexel’s College of Engineering and head of the A.J. Drexel Nanomaterials Institute, who was an author of the paper. “The trick in this work is that the crystal structure of salt must match the crystal structure of the oxide, otherwise it will form an amorphous film of oxide rather than a thing, strong and stable nanocrystal. This is the key finding of our research—it means that different salts must be used to produce different oxides.”
Researchers have used a variety of chemicals, compounds, polymers and objects as growth templates for nanomaterials. But this discovery shows the importance of matching a template to the structure of the material being grown. Salt crystals turn out to be the perfect substrate for growing oxide sheets of magnesium, molybdenum and tungsten.
The precursor solution coats the sides of the salt crystals as the oxides begin to form. After they’ve solidified, the salt is dissolved in a wash, leaving nanometer-thin two-dimensional sheets that formed on the sides of the salt crystal—and little trace of any contaminants that might hinder their energy storage performance. By making oxide nanosheets in this way, the only factors that limit their growth is the size of the salt crystal and the amount of precursor solution used.
“Lateral growth of the 2D oxides was guided by salt crystal geometry and promoted by lattice matching and the thickness was restrained by the raw material supply. The dimensions of the salt crystals are tens of micrometers and guide the growth of the 2D oxide to a similar size,” the researchers write in the paper. “On the basis of the naturally non-layered crystal structures of these oxides, the suitability of salt-assisted templating as a general method for synthesis of 2D oxides has been convincingly demonstrated.”
As predicted, the larger size of the oxide sheets also equated to a greater ability to collect and disburse ions from an electrolyte solution—the ultimate test for its potential to be used in energy storage devices. Results reported in the paper suggest that use of these materials may help in creating an aluminum-ion battery that could store more charge than the best lithium-ion batteries found in laptops and mobile devices today.
Gogotsi, along with his students in the Department of Materials Science and Engineering, has been collaborating with Huazhong University of Science and Technology since 2012 to explore a wide variety of materials for energy storage application. The lead author of the Nature Communications article, Xu Xiao, and co-author Tiangi Li, both Zhou’s doctoral students, came to Drexel as exchange students to learn about the University’s supercapacitor research. Those visits started a collaboration, which was supported by Gogotsi’s annual trips to HUST. While the partnership has already yielded five joint publications, Gogotsi speculates that this work is only beginning.
“The most significant result of this work thus far is that we’ve demonstrated the ability to generate high-quality 2D oxides with various compositions,” Gogotsi said. “I can certainly see expanding this approach to other oxides that may offer attractive properties for electrical energy storage, water desalination membranes, photocatalysis and other applications.”
Canada has a chance to add a new dimension to its energy economy – one that is clean, profitable and globally groundbreaking.
The opportunity is electricity storage, which until now has been limited by technology to a relatively modest scale. That’s about to change. And it means that Canada – and specifically Ontario – can become an ideal seedbed for storage technology, because there are ready markets for both large- and small-scale storage systems.
First, the large scale. Ontario has a fleet of nuclear generators that operate around the clock, and come close to filling the demand for power at off-peak hours. In addition, Ontario has developed a large renewable energy sector of wind and solar generation (in addition to its traditional hydro stations.) Problems sometimes arise when the natural weather cycles that drive wind and solar production are out of synch with the market cycle. On a sunny, breezy Saturday afternoon in May, with the nuclear plants running flat out, the hydro stations churning out power with the spring runoff and solar and wind systems near peak production, Ontario may have more electricity than it needs.
Our electricity system operators have a solution, of course: Sell the excess electricity to our neighbours. But since our neighbours are often in the same boat, Ontario must cut the price close to zero – or in extreme situations, even pay neighbouring states or provinces to absorb our overproduction.
Wouldn’t it make far more sense to store that excess energy, knowing that it will be needed in a matter of days, or even hours? What’s been lacking is the technology to do the job.
That’s changing however, as Ontario’s current program to procure 50 megawatts of storage capacity demonstrates. Companies with a variety of approaches are working hard to bring their solutions to market – many of them clustered at the MaRS centre in Toronto. Some, such as Hydrogenics Corp., convert electricity into hydrogen, which can be used to supplement natural gas.
My own company, NRStor, has partnered with Temporal Power and is operating a flywheel storage system in Minto, Ont., that helps the market operator to maintain consistent voltage on the grid.
Of course, businesses around the globe are looking at the same opportunities as we are, and here lies the opportunity for Canada to rebrand its energy economy.
A recent report by Deutsche Bank calls battery storage the “holy grail of solar penetration,” and believes that with the current rate of progress in improving efficiency, mass adoption of lithium ion batteries at a commercial/utility scale could occur before 2020.
Analysis by Prof. Andrew Ford of Washington State University calculates that a 1,000-megawatt air storage system from U.S.-based General Compression Inc. could deliver $6- to $8-billion of value to Ontario – in the form of lower energy costs to local utilities – over a 20-year period. All this is of interest to large-scale electricity system operators, big utilities and their customers.
But there is another reason for us to pay attention to energy storage – a reason grounded on a much more human scale. There are still large rural areas around the globe where there is no reliable electrical grid – including Northern Canada.
There is great potential for these communities, including remote First Nations communities, to improve their standard of living by installing microscale renewable generation in combination with storage, and relying less on carbon-spewing diesel generators, powered by fuel that must be transported long distances at great expense.
Storage is the key to making renewable energy a fully competitive component of any electrical grid. It can make our grid cleaner and more efficient, for the benefit of all consumers – large and small, urban and rural. We have the chance, in Canada, to become world leaders in developing this technology. Let’s seize it.
Annette Verschuren is the chairwoman and CEO of NRStor and on the board of MaRS Discovery District.
A discovery made in Leiden helps not only to make natural gas from CO2 but also to store renewable energy. Research by Professor Marc Koper and PhD student Jing Shen shows how this process can be implemented in a cost-effective and controllable way.
The conversion of the greenhouse gas CO2 into natural gas is achieved using a chemical process in which CO2 is bubbled through an acid solution. The solution contains a graphite electrode — to which a small negative voltage is applied — with a cobalt-porphyrin catalyst attached to it. It was already known that this catalyst can convert CO2 into carbon monoxide and methane, but the reaction always released unwanted hydrogen. In their investigation, Koper and Shen show for the first time how the process works. They therefore know exactly what the best acidity degree is in order to minimise the amount of hydrogen and to convert as much CO2 as possible into natural gas.
An added benefit is that the catalyst is entirely made up of common materials. Cobalt porphyrin is a part of vitamin B12, while the graphite for the electrode is similar to a pencil lead. Therefore the catalyst only costs a few euros. Comparable methods of converting CO2 into methane often use rare and expensive metals, such as platinum.
Realising a dream
Koper hopes that this discovery will bring his dream a little closer to realisation: to convert CO2 and water, the by-products of fuels, into new energy or building blocks for the chemical industry. If this can be achieved using solar energy, this process will also offer a method of storing renewable energy.
Using renewable energy efficiently
‘We’re generating more and more electricity using solar panels and windmills, but that energy is by no means always used straight away,’ Koper explains. ‘In Germany, for example, too much renewable electricity is generated sometimes, so you want to store it. That is the most important potential application of our research: to use renewable energy efficiently by converting water and CO2 into valuable products.’
A fundamentally different way
Still, Koper thinks that it will take a while to get to that point. ‘This is something for the long term and it could be another fifty years before we have a method that makes valuable products and is also robust, scalable and cost-effective. But I’m nevertheless convinced that this is the way to go. It will not be easy, but this discovery is helpful. We have to find a fundamentally different way to manage energy, and our discovery can contribute to that.’
Jing Shen, Ruud Kortlever, Recep Kas, Yuvraj Y. Birdja, Oscar Diaz-Morales, Youngkook Kwon, Isis Ledezma-Yanez, Klaas Jan P. Schouten, Guido Mul, Marc T. M. Koper. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin. Nature Communications, 2015; 6: 8177 DOI: 10.1038/ncomms9177
Chemists at the University of Waterloo have discovered the key reaction that takes place in sodium-air batteries that could pave the way for development of the so-called holy grail of electrochemical energy storage. Researchers from the Waterloo Institute for Nanotechnology, led by Professor Linda Nazar who holds the Canada Research Chair in Solid State Energy Materials, have described a key mediation pathway that explains why sodium-oxygen batteries are more energy efficient compared with their lithium-oxygen counterparts.
Understanding how sodium–oxygen batteries work has implications for developing the more powerful lithium–oxygen battery, which is seen as the holy grail of electrochemical energy storage. Their results appear in the journal Nature Chemistry. “Our new understanding brings together a lot of different, disconnected bits of a puzzle that have allowed us to assemble the full picture,” says Nazar, a Chemistry professor in the Faculty of Science. “These findings will change the way we think about non-aqueous metal-oxygen batteries.”
Oxygen is reduced at the surface of the cathode to form superoxide and reacts with trace water to form soluble HO2. The latter undergoes metathesis with Na+, driven by the free energy of formation of crystalline NaO2, to form cubic nuclei that crystallize from solution. Growth of the NaO2 from solution to form micrometre-sized cubes occurs via epitaxial growth promoted by phase-transfer catalysis of the superoxide from solution to the solid.
Sodium-oxygen batteries are considered by many to be a particularly promising metal-oxygen battery combination. Although less energy dense than lithium–oxygen cells, they can be recharged with more than 93 per cent efficiency and are cheap enough for large-scale electrical grid storage. The key lies in Nazar’s group discovery of the so-called proton phase transfer catalyst. By isolating its role in the battery’s discharge and recharge reactions, Nazar and colleagues were not only able to boost the battery’s capacity, they achieved a near-perfect recharge of the cell. When the researchers eliminated the catalyst from the system, they found the battery no longer worked.
Oxygen is reduced at the surface of the cathode to form superoxide and reacts with trace water to form soluble HO2. The latter undergoes metathesis with Na+, driven by the free energy of formation of crystalline NaO2, to form cubic nuclei that crystallize from solution. Growth of the NaO2 from solution to form micrometre-sized cubes occurs via epitaxial growth promoted by phase-transfer catalysis of the superoxide from solution to the solid.
“These findings will change the way we think about non-aqueous metal-oxygen batteries.” – Professor Linda Nazar Canada Research Chair in Solid-State Energy Materials University of Waterloo
Unlike the traditional solid-state battery design, a metal-oxygen battery uses a gas cathode that takes oxygen and combines it with a metal such as sodium or lithium to form a metal oxide, storing electrons in the process. Applying an electric current reverses the reaction and reverts the metal to its original form.
In the case of the sodium–oxygen cell, the proton phase catalyst transfers the newly formed sodium superoxide (NaO2) entities to solution where they nucleate into well-defined nanocrystals to grow the discharge product as micron-sized cubes.The dimensions of the initially formed NaO2 are critical; theoretical calculations from a group at MIT has separately shown that NaO2 is energetically preferred over sodium peroxide, Na2O2 at the nanoscale.When the battery is recharged, these NaO2 cubes readily dissociate, with the reverse reaction facilitated once again by the proton phase catalyst. Chemistry says that the proton phase catalyst could work similarly with lithium-oxygen. However, the lithium superoxide (LiO2) entities are too unstable and convert immediately to lithium peroxide (Li2O2). Once Li2O2 forms, the catalyst cannot facilitate the reverse reaction, as the forward and reverse reactions are no longer the same.So, in order to achieve progress on lithium–oxygen systems, researchers need to find an additional redox mediator to charge the cell efficiently. ”We are investigating redox mediators as well as exploring new opportunities for sodium–oxygen batteries that this research has inspired,” said Nazar. “Lithium–oxygen and sodium-oxygen batteries have a very promising future, but their development must take into account the role of how high capacity – and reversibility – can be scientifically achieved.” Postdoctoral research associate Chun Xia along with doctoral students Robert Black, Russel Fernandes, and Brian Adams co-authored the paper.
The ecoENERGY Innovation Initiative program of Natural Resources Canada, and the Natural Sciences and Engineering Research Council (NSERC) of Canada funded the project.
Rice University scientists advanced their recent development of laser-induced graphene (LIG) by producing and testing stacked, three-dimensional supercapacitors, energy-storage devices that are important for portable, flexible electronics.
The Rice lab of chemist James Tour discovered last year that firing a laser at an inexpensive polymer burned off other elements and left a film of porous graphene, the much-studied atom-thick lattice of carbon. The researchers viewed the porous, conductive material as a perfect electrode for supercapacitors or electronic circuits.
To prove it, members of the Tour group have since extended their work to make vertically aligned supercapacitors with laser-induced graphene on both sides of a polymer sheet. The sections are then stacked with solid electrolytes in between for a multilayer sandwich with multiple microsupercapacitors.
A schematic shows the process developed by Rice University scientists to make vertical microsupercapacitors with laser-induced graphene. The flexible devices show potential for use in wearable and next-generation electronics. (Courtesy of the Tour Group)
The flexible stacks show excellent energy-storage capacity and power potential and can be scaled up for commercial applications. LIG can be made in air at ambient temperature, perhaps in industrial quantities through roll-to-roll processes, Tour said.
Capacitors use an electrostatic charge to store energy they can release quickly, to a camera’s flash, for example. Unlike chemical-based rechargeable batteries, capacitors charge fast and release all their energy at once when triggered. But chemical batteries hold far more energy. Supercapacitors combine useful qualities of both – the fast charge/discharge of capacitors and high-energy capacity of batteries – into one package.
LIG supercapacitors appear able to do all that with the added benefits of flexibility and scalability. The flexibility ensures they can easily conform to varied packages – they can be rolled within a cylinder, for instance – without giving up any of the device’s performance.
“What we’ve made are comparable to microsupercapacitors being commercialized now, but our ability to put devices into a 3-D configuration allows us to pack a lot of them into a very small area,” Tour said. “We simply stack them up.
“The other key is that we’re doing this very simply. Nothing about the process requires a clean room. It’s done on a commercial laser system, as found in routine machine shops, in the open air.”
An electron microscope image shows the cross section of laser-induced graphene burned into both sides of a polyimide substrate. The flexible material created at Rice University has the potential for use in electronics or for energy storage. (Courtesy of the Tour Group)
Ripples, wrinkles and sub-10-nanometer pores in the surface and atomic-level imperfections give LIG its ability to store a lot of energy. But the graphene retains its ability to move electrons quickly and gives it the quick charge-and-release characteristics of a supercapacitor. In testing, the researchers charged and discharged the devices for thousands of cycles with almost no loss of capacitance.
To show how well their supercapacitors scale up for applications, the researchers wired pairs of each variety of device in serial and parallel. As expected, they found the serial devices delivered double the working voltage, while the parallels doubled the discharge time at the same current density.
The vertical supercapacitors showed almost no change in electrical performance when flexed, even after 8,000 bending cycles.
Tour said that while thin-film lithium ion batteries are able to store more energy, LIG supercapacitors of the same size offer three times the performance in power (the speed at which energy flows). And the LIG devices can easily scale up for increased capacity.
“We’ve demonstrated that these are going to be excellent components of the flexible electronics that will soon be embedded in clothing and consumer goods,” he said.