Nanotechnology breakthrough enables conversion of infrared light to energy

A close up of the film which combines nanocrystals and microlenses to capture infrared light and convert it to solar energy. Credit: KTH Royal Institute of Technology

Invisible infrared light accounts for half of all solar radiation on the Earth’s surface, yet ordinary solar energy systems have limited ability in converting it to power. A breakthrough in research at KTH could change that.

A research team led by Hans Ågren, professor in theoretical chemistry at KTH Royal Institute of Technology, has developed a film that can be applied on top of ordinary solar cells, which would enable them to use infrared light in energy conversion and increase efficiency by 10 percent or more.

“We have achieved a 10 percent increase in efficiency without yet optimizing the technology,” Ågren says. “With a little more work, we estimate that a 20 to 25 percent increase in efficiency could be achieved.”

Photosensitive materials used in solar cells, such as the mineral perovskite, have a limited ability to respond to infrared light. The solution, developed with KTH researchers Haichun Liu and Qingyun Liu, was to combine nanocrystals with chains of microlenses.

“The ability of the microlenses to concentrate light allows the nanoparticles to convert the weak IR light radiation to visible light useful for solar cells,” Ågren says.

The research progress has been patented, and presented in the scientific journal Nanoscale.

More information: Qingyun Liu et al. Microlens array enhanced upconversion luminescence at low excitation irradiance, Nanoscale (2019). DOI: 10.1039/c9nr03105g

Journal information: Nanoscale

Provided by KTH Royal Institute of Technology

Combining Blockchain and Nanotechnology to Fight Criminal Counterfeiters and Build Brand Trust

Say the word “blockchain” to businesspeople and you’re likely to be met with either a “never heard of it” or an “it’s also called bitcoin isn’t it?” response. These kinds of comments are probably well known to those involved in nanotechnology. The reality is that neither of these transformational technologies are yet widely understood, and real-world applications are only now emerging to address business opportunities.

While blockchain is perhaps best known as the technology that underpins the (somewhat notorious) cryptocurrency called bitcoin, it can be applied to many different business areas like finance, healthcare, identity and supply chain. Major IT companies, such as IBM, Microsoft, SAP and Oracle, have invested big in making blockchain usable by business enterprises for these applications, and more.

In this article, we’ll highlight how the combination of blockchain and nanotechnology can be applied to a particularly challenging aspect of supply chain management, namely the huge global criminal marketplace in counterfeit goods, which hurts business profits, impacts brand trust and undermines customer relationships.

First, a quick primer on blockchain. A blockchain is a type of database that is tamper proof. Data stored in a blockchain cannot be changed (the technical term is immutable), it can be shared among multiple users, and significantly the composition of the data stored is agreed to by multiple users of the blockchain before it can be stored (this process is known as consensus). In short, blockchains are an incredibly secure way to keep information safe and consistent among multiple participants in a business network.

READ MORE: How Blockchain Technology Could Be The Primary Key To Cybersecurity

Next, a few words about the shadowy world of counterfeit goods. Sadly, it’s a big business for criminals. Recent industry statistics suggest counterfeiting is a $1.8 Trillion endeavor that spans the globe. Just about every product is a target for counterfeiters – luxury fashion accessories, wine, auto parts, pharmaceuticals, sports apparel and consumer electronics are common examples – and this activity impacts businesses and their brands both financially and reputationally and can represent a significant safety risk for consumers.

So how is the combination of blockchain and nanotechnology being leveraged to fight the counterfeiters?

At Quantum Materials Corp. we have developed nanomaterials called quantum dots over the past decade. Quantum dots are nanoscale semiconductor particles that possess notable and extremely useful optical and electrical properties. They measure from 10 to 100 atoms in size (approximately 10,000 dots would fit across the diameter of a human hair) and they generate light when energy is applied to them or generate energy when light is applied.

QMC creates in commercial quantities quantum dots that can be finely tuned to emit predetermined wavelengths of light (in both the visible and non-visible spectrums) with the ability to create billions of unique optical signatures. Moreover, they are excitable by numerous excitation energy sources.

Our quantum dots can be incorporated into almost any physical item at time of manufacture, and then provide a unique light signature that establishes absolute product identity. These identities are impossible to copy or clone so that products enhanced by them can be verified as being genuine items and not counterfeits.

 

Read About Another New Quantum Dot Security Company Dotz Nano ~ Tag – Trace – Verify

Dotz is a technology leader, specializing in the development and marketing of novel advanced carbon-based materials used for tracing, anti-counterfeiting and product-liability solutions. Our unique products: ValiDotz ™, Fluorensic™, and BioDotz™ can be imbedded into plastics, fuels, lubricants, chemicals, and even Cannabis  plants to create product specific codes and trace for origin  Follow Dotz Nano on Twitter

When the quantum dot signature of a product is scanned (via a hand-held scanner or an app on a smartphone), a digital representation is created that is stored on our secure and tamper-proof blockchain platform. It is this platform that allows for tracking of products providing visibility among all participants in their supply chain – from manufacture to customer purchase.

In addition, the blockchain platform is also used to store the unique digital identities of individual customers, and to tie ownership of a product to a customer at purchase time. No longer is it necessary to keep the receipt!

For example, a customer purchasing a luxury handbag that has QMC’s quantum dots incorporated into it by its manufacturer can use their smartphone to scan the bag to give them confidence that the bag is genuine. As a bonus, the manufacturer is notified that the bag’s authenticity has been checked and can offer a warranty or loyalty program to the customer in order to establish an enduring brand/customer relationship.

The bottom line for blockchain plus nanotechnology is that … it certainly impacts the bottom line. Surveys conducted by retailers point to customers not only appreciating being able to prove product authenticity but tending to buy more products where that functionality is available. They also frequent the retailer more often. Almost everyone is a winner – the customer, the retailer and the product brand. The criminal counterfeiters? Not so much.

By Stephen Squires, Founder & CEO, Quantum Materials Corp

MIT engineers develop a new way to remove carbon dioxide from air

In this diagram of the new system, air entering from top right passes to one of two chambers (the gray rectangular structures) containing battery electrodes that attract the carbon dioxide. Then the airflow is switched to the other chamber, while the accumulated carbon dioxide in the first chamber is flushed into a separate storage tank (at right). These alternating flows allow for continuous operation of the two-step process. Image courtesy of the researchers

The process could work on the gas at any concentrations, from power plant emissions to open air

A new way of removing carbon dioxide from a stream of air could provide a significant tool in the battle against climate change. The new system can work on the gas at virtually any concentration level, even down to the roughly 400 parts per million currently found in the atmosphere.

Most methods of removing carbon dioxide from a stream of gas require higher concentrations, such as those found in the flue emissions from fossil fuel-based power plants. A few variations have been developed that can work with the low concentrations found in air, but the new method is significantly less energy-intensive and expensive, the researchers say.

The technique, based on passing air through a stack of charged electrochemical plates, is described in a new paper in the journal Energy and Environmental Science, by MIT postdoc Sahag Voskian, who developed the work during his PhD, and T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering.

The device is essentially a large, specialized battery that absorbs carbon dioxide from the air (or other gas stream) passing over its electrodes as it is being charged up, and then releases the gas as it is being discharged. In operation, the device would simply alternate between charging and discharging, with fresh air or feed gas being blown through the system during the charging cycle, and then the pure, concentrated carbon dioxide being blown out during the discharging.

As the battery charges, an electrochemical reaction takes place at the surface of each of a stack of electrodes. These are coated with a compound called poly-anthraquinone, which is composited with carbon nanotubes. The electrodes have a natural affinity for carbon dioxide and readily react with its molecules in the airstream or feed gas, even when it is present at very low concentrations. The reverse reaction takes place when the battery is discharged — during which the device can provide part of the power needed for the whole system — and in the process ejects a stream of pure carbon dioxide. The whole system operates at room temperature and normal air pressure.

“The greatest advantage of this technology over most other carbon capture or carbon absorbing technologies is the binary nature of the adsorbent’s affinity to carbon dioxide,” explains Voskian. In other words, the electrode material, by its nature, “has either a high affinity or no affinity whatsoever,” depending on the battery’s state of charging or discharging. Other reactions used for carbon capture require intermediate chemical processing steps or the input of significant energy such as heat, or pressure differences.

“This binary affinity allows capture of carbon dioxide from any concentration, including 400 parts per million, and allows its release into any carrier stream, including 100 percent CO₂,” Voskian says. That is, as any gas flows through the stack of these flat electrochemical cells, during the release step the captured carbon dioxide will be carried along with it. For example, if the desired end-product is pure carbon dioxide to be used in the carbonation of beverages, then a stream of the pure gas can be blown through the plates. The captured gas is then released from the plates and joins the stream.

In some soft-drink bottling plants, fossil fuel is burned to generate the carbon dioxide needed to give the drinks their fizz. Similarly, some farmers burn natural gas to produce carbon dioxide to feed their plants in greenhouses. The new system could eliminate that need for fossil fuels in these applications, and in the process actually be taking the greenhouse gas right out of the air, Voskian says. Alternatively, the pure carbon dioxide stream could be compressed and injected underground for long-term disposal, or even made into fuel through a series of chemical and electrochemical processes.

The process this system uses for capturing and releasing carbon dioxide “is revolutionary” he says. “All of this is at ambient conditions — there’s no need for thermal, pressure, or chemical input. It’s just these very thin sheets, with both surfaces active, that can be stacked in a box and connected to a source of electricity.”

“In my laboratories, we have been striving to develop new technologies to tackle a range of environmental issues that avoid the need for thermal energy sources, changes in system pressure, or addition of chemicals to complete the separation and release cycles,” Hatton says. “This carbon dioxide capture technology is a clear demonstration of the power of electrochemical approaches that require only small swings in voltage to drive the separations.”​

In a working plant — for example, in a power plant where exhaust gas is being produced continuously — two sets of such stacks of the electrochemical cells could be set up side by side to operate in parallel, with flue gas being directed first at one set for carbon capture, then diverted to the second set while the first set goes into its discharge cycle. By alternating back and forth, the system could always be both capturing and discharging the gas. In the lab, the team has proven the system can withstand at least 7,000 charging-discharging cycles, with a 30 percent loss in efficiency over that time. The researchers estimate that they can readily improve that to 20,000 to 50,000 cycles.

The electrodes themselves can be manufactured by standard chemical processing methods. While today this is done in a laboratory setting, it can be adapted so that ultimately they could be made in large quantities through a roll-to-roll manufacturing process similar to a newspaper printing press, Voskian says. “We have developed very cost-effective techniques,” he says, estimating that it could be produced for something like tens of dollars per square meter of electrode.

Compared to other existing carbon capture technologies, this system is quite energy efficient, using about one gigajoule of energy per ton of carbon dioxide captured, consistently. Other existing methods have energy consumption which vary between 1 to 10 gigajoules per ton, depending on the inlet carbon dioxide concentration, Voskian says.

The researchers have set up a company called Verdox to commercialize the process, and hope to develop a pilot-scale plant within the next few years, he says. And the system is very easy to scale up, he says: “If you want more capacity, you just need to make more electrodes.”

This work was supported by an MIT Energy Initiative Seed Fund grant and by Eni S.p.A.

A new method of extracting hydrogen from water more efficiently to capture renewable energy

Crystal structure and {MoTe}6 polyhedra showing the building blocks of each polymorph. a monoclinic 1T′-MoTe2 phase and b hexagonal 2H-MoTe2 phase. Credit: Nature Communications 10.1038/s41467-019-12831-0

A new method of extracting hydrogen from water more efficiently could help underpin the capture of renewable energy in the form of sustainable fuel, scientists say.

In a new paper, published today in the journal Nature Communications, researchers from universities in the UK, Portugal, Germany and Hungary describe how pulsing electric currentthrough a layered catalyst has allowed them to almost double the amount of hydrogen produced per millivolt of electricity used during the process.

Electrolysis, a process which is likely familiar to anyone who studied chemistry at high school, uses electric current to split the bonds between the hydrogen and oxygen atoms of water, releasing hydrogen and oxygen gas.

If the electric current for the process of electrolysis is generated through renewable means such as wind or solar power, the entire process releases no additional carbon into the atmosphere, making no contributions to climate change. Hydrogen gas can then be used as a zero-emission fuel source in some forms of transport such as buses and cars or for heating homes.

The team’s research focused on finding a more efficient way to produce hydrogen through the electrocatalytic water splitting reaction. They discovered that electrodes covered with a molybedenum telluride catalyst showed an increase in the amount of hydrogen gas produced during the electrolysis when a specific pattern of high-current pulses was applied.

By optimising the pulses of current through the acidic electrolyte, they could reduce the amount of energy needed to make a given amount of hydrogen by nearly 50%.

Dr. Alexey Ganin, of the University of Glasgow’s School of Chemistry, directed the research team. Dr. Ganin said: “Currently the UK meets about a third of its energy production needs through renewable sources, and in Scotland that figure is about 80%.

“Experts predict that we’ll soon reach a point where we’ll be producing more renewable electricity than our consumption demands. However, as it currently stands the excess of generated energy must be used as it’s produced or else it goes to waste. It’s vital that we develop a robust suite of methods to store the energy for later use.

“Batteries are one way to do that, but hydrogen is a very promising alternative. Our research provides an important new insight into producing hydrogen from electrolysis more effectively and more economically, and we’re keen to pursue this promising avenue of investigation.”

Since the level of catalytic enhancement is controlled by electric currents, recent advances in machine learning could be used to fine-tune the right sequence of applied currents to achieve the maximum output.

The next stage for the team is the development of an artificial intelligence protocol to replace human input in the search for the most effective electronic structures use in similar catalytic processes.

The paper, titled “The rapid electrochemical activation of MoTe2 for the hydrogen evolution reaction,” is published in Nature Communications

More information: The rapid electrochemical activation of MoTe2 for the hydrogen evolution reaction, Nature Communicationsdoi.org/10.1038/s41467-019-12831-0 , www.nature.com/articles/s41467-019-12831-0

Journal information: Nature Communications

Provided by University of Glasgow

Sealed cell improves oxide-peroxide conversion in lithium-ion battery

Sealed for success. Oxygen-free cells improve lithium-ion batteries. Credit: battery supply 866599918 iStock MF3d

A new high-energy density and stable lithium-ion battery that works by reversible oxide-peroxide conversion could help in the development of improved “sealed” battery technologies. This is the new result from a team of researchers in Japan and China who have designed an oxygen-free cell in which the Li₂O to Li₂O₂ reaction can take place.

Lithium-ion batteries are hitting the headlines this week with news of this year’s Nobel Prize for Chemistry being awarded to John Goodenough, Stanley Whittingham and Akira Yoshino for the development of these devices.

Lithium is the material of choice in these batteries because it has a high specific capacity and low electrochemical potential. In recent years, focus has shifted from the rigid Li-intercalation structures commonly employed in the conventional heavy lithium-transition metal oxide cathodes used in these devices to Li-O₂ battery technology that exploits oxygen-related redox chemistries that have excellent theoretical gravimetric energy densities. 

Redox reaction between O₂ and Li₂O₂

These batteries work thanks to the redox reaction between O₂ and lithium peroxide, Li₂O₂. One of the main hurdles hindering their practical application, however, is that they require O₂ gas as the active species. This needs to be supplied by bulky O₂ storage or gas purification devices.

To overcome this problem, and the so-called O₂ crossover and electrolyte volatilization in these batteries, researchers led by Haoshen Zhou of the National Institute of Advanced Industrial Science and Technology (AIST) and Nanjing University in China have now designed an O₂-free sealed environment for the Li₂O to Li₂O₂ reaction.

The sealed Li₂O/Li₂O₂ battery system and photographs of the principal investigators. Courtesy: H Zhou

High-energy density, rechargeable and stable Li-ion battery

Zhou and colleagues did this by embedding Li₂O nanoparticles into an iridium-reduced graphene oxide (Ir-rGO) catalytic substrate to successfully control the charging potential within a small region of the device and avoid the unwanted phenomenon of over-polarization.

“The choice of Ir nanoparticles as the catalyst is key, as is the conductive rGO substrate,” explains Zhou. “The Ir can effectively enhance the reaction kinetics and protect the newly formed Li₂O₂ from further decomposition (by the formation of the inter-metallic Li_2-xO₂-Ir compound formed on the particles/substrate interface) while the rGO allows for the remarkable electrical conductivity of the system.”

The researchers also restrained two other serious problems that beset sealed redox systems: the irreversible evolution of O₂ and the production of superoxide (an aggressive and dangerous product). They did this by controlling the degree of the electrochemical reaction and its cycling depth and thus succeeded in producing a reversible capacity for the device of 400 mAh/g, a value that fares well when compared to other cathode candidates for Li-ion batteries.

The result is a high-energy density (1090 Wh/kg), high energy efficiency (a mere 0.12 V polarization potential), rechargeable Li-ion battery technology that is stable over 2000 cycles with 99.5% coulombic efficiency.

READ MORE

Lithium-ion battery pioneers bag chemistry Nobel prize

 

Although he and his colleagues still need to fully understand the catalysis mechanism at play in the cell, Zhou believes that the sealed Li₂O/Li₂O₂ battery system could gradually replace today’s open-cell Li-O₂ batteries and even become a a “hot” topic for next-generation battery research. “From an applications viewpoint, the very competitive properties of the sealed system could help in the development of cathode materials for commercial Li-ion battery technology,” he tells Physics World.

The researchers, reporting their work in Nature Catalysis 10.1038/s41929-019-0362-z, say they are now looking for more effective catalysts to further boost the reversible capacity region in their device and enhance the reaction kinetics.

Microscale acoustic “rockets” navigate the human body

Engineers turn bubbles into motors to propel minute vessels through landscapes of cells and particles suspended in fluid

Ever since nanotechnology became a real branch of engineering, its practitioners have been trying to design tiny structures that can work like submarines to navigate through the human body.

One stumbling block towards this goal has been what fuels and motor analogues could be used to propel and steer such nano-vessels around and inside blood vessels and organs without causing harm.

Researchers at Pennsylvania State University and the University of San Diego hit a wall with their research, because they were using toxic materials like hydrogen peroxide as fuel. A fortuitous discovery about the behaviour of bubbles has opened up a new avenue for their research, as they describe in Science Advances.

Working with material scientists at the Harbin Institute of technology in Shenzhen and surgeons at University of Michigan, Thomas Mallouk of the Department of Chemistry at Penn State was trying to move nano-vessels with acoustic levitation, a technique used to lift particles off microscope slides. Unexpectedly, he found that high-frequency sound waves made the vessels move at very fast speeds. Investigating this phenomenon further, Mallouk and his team designed microscale “rockets” that can use acoustics to zip around and steer in a liquid medium.

The rockets are not rocket-shaped. They resemble a round-bottomed cup 10µm in length and 5µm wide, 3D printed from a polymer and coated with a 10nm-thick layer of nickel and a 40nm-thick layer of gold.

The inside of the cup is then coated with trichlorosilane, which repels water. When submerged in fluid, an air bubble spontaneously forms inside the cup. When bombarded with ultrasound waves, the bubble vibrates, turning it into a motor and propelling it through the fluid. The vessel can be steered with precision by manipulating an external magnetic field. Each rocket has a characteristic resonant frequency, so individual vessels can be driven independently.

Steering of the vessels is so precise that Mallouk’s team made them move up microscopic staircase structures. The addition of fins to the cup structures allows them to be steered freely in three dimensions.

Moreover, the team describes using the vessels to push other particles or cells around, or tow them with precision through a crowded environment. The key to this is the small size of the vessels, Mallouk claims.

“This wasn’t available on a larger scale,” he said. “There’s a lot of control you can do at this length scale. At this particular length scale, we’re right at the crossover point between when the power is enough to affect other particles.”

Changing the acoustic stimulation adjusts the speed of the vessels. “If I want it to go slow, I can turn the power down, and if I want it to go really fast, I can turn the power up,” explains Jeff McNeill, a graduate student who works on nano-and microscale motor projects. “That’s a really useful tool.”

Mallouk is working with engineers and roboticists at Penn to equip the vessels with computer chips and sensors to give them autonomy and intelligence, which would allow them to be used for tasks including imaging and even surgery. “We’d like to have controllable robots that can do tasks inside the body: delivering medicine, diagnostic snooping,” he said.

Unique Rice platform helps bioscientists learn how ectoderm cells begin to differentiate

During embryonic development, the entire nervous system, the skin and the sensory organs emerge from a single sheet of cells known as the ectoderm. While there have been extensive studies of how this sheet forms all these derivatives, it hasn’t been possible to study the process in humans – until now.

Rice bioscientist Aryeh Warmflash, graduate student George Britton and their colleagues have created a system in which all of the major cell types of ectoderm are formed in a culture dish in a pattern similar to that seen in embryos.This technique, based on controlling the geometry of stem cell colonies with microscale patterns, has helped them make the most comprehensive analysis yet of signaling pathways that drive patterning of human ectoderm.

“There are very few possible signals the embryo uses to generate the wide variety of cell types that arise,” Britton said. “We want to understand the timing of these signals and how the cells interpret them in time to generate this variety.”

It revealed that the balance between two signaling pathways, BMP and Wnt, are both critical, and even a bit adaptable as they orchestrate patterning in the ectoderm. The logic they employ ultimately drives ectodermal cells to their fates, but the research showed they can take more than one road to get there.

Britton said the micro-patterned plates and a better understanding of how the signaling pathways work let them manipulate stem cell colonies to form unusual patterns at the start, but ultimately they always seemed to converge at the same place. “We found different trajectories of the signals that arrived at the same pattern,” he said. That suggested the system by which stem cells become neurons, neural crest cells, neurogenic placodes and epidermis cells is pretty robust.

“A lot of people are interested in the transcription factor network that directs neural crest emergence, so this is a powerful system to dissect the signals that contribute to that logic,” Britton said. “That was one thing we feel we contributed to the field.

“There’s also the idea that cells that have the ability to interpret relative levels of BMP and Wnt to incorporate the appropriate fate decision,” he said. “In the embryo, cells are moving around quite a bit in a space where signals and the ligands they’re exposed to are also moving around. It might be that cells are reading the relative levels to determine a certain fate.”

The researchers observed that the relative activity of BMP and Wnt signaling determines cells’ decisions to become either neural crest or placodal cells, while BMP alone initiates and controls the size of the surface ectoderm, all within about the first four days.

“Four days is about right in the sense that cells are starting to make decisions: ‘I’m going to be a placodal cell, I’m going to be a neural crest cell, I’m going to be neural fate and I’m going to an epidermal fate,” Britton said.

“We see that approximately a day or two after BMP treatment. But it’s hard to put a finger on whether these are the final patterns,” he said. “We’d have to do a more careful observation to make sure those placodal cells don’t change to neural crest cells, or vice versa. That will give us information on how these lineages and fates settle into a final pattern, maybe by day 6 or 7.”

He said future studies will further refine their understanding of how signaling patterns work, as well as how the development of all the germ layers collaborate.

“Until now, studies of human stem cells differentiating to ectodermal fates were mostly about how to get all the cells in your culture dish to become a particular cell type; for example, how to make a dish full of neurons,” Warmflash said. “We are interested in a different question: How do cells interact with each other to make patterns of different cell fates? The system we developed does this outside the embryo and is allowing us to begin to tackle this question.”

Rice University

University of Sydney – Make Like a Leaf: ‘Carbon Photosynthesis’ With Nanotechnology to Convert CO2 Into Fuels

Researchers develop process for carbon dioxide conversion.

University of Sydney researchers are drawing inspiration from leaves to reduce carbon emissions, using nanotechnology to develop a method for ‘carbon photosynthesis’ that they hope will one day be adopted on an industrial scale.

Professor Jun Huang from the University of Sydney Nano Institute and the School of Chemical and Biomolecular Engineering is developing a carbon capture method that aims to go one step beyond storage, instead converting and recycling carbon dioxide (CO2) into raw materials that can be used to create fuels and chemicals.

” Drawing inspiration from leaves and plants, we have developed an artificial photosynthesis method,” said Professor Huang.

To simulate photosynthesis, we have built microplates of carbon layered with carbon quantum dots with tiny pores that absorb CO₂  and water.

“Once carbon dioxide and water are absorbed, a chemical process occurs that combines both compounds and turns them into hydrocarbon, an organic compound that can be used for fuels, pharmaceuticals, agrichemicals, clothing, and construction.

“Following our most recent findings, the next phase of our research will focus on large-scale catalyst synthesis and the design of a reactor for large scale conversion,” he said.

While the research has been conducted on a nanoscale, Professor Huang hopes the technology will be used by power stations to capture emissions from burning fossil fuels.

“Our CO₂ absorbent plates may be small, but our goal is to now create large panels, similar to solar panels, that would be used by industry to absorb and convert large volumes of CO₂ ,” said Professor Huang.

CO emissions from the burning of fossil fuels and transport are the main cause of global warming, contributing up to 65 percent of the total global greenhouse gas emissions.

While plants ‘breathe’ in CO₂ , a process called photosynthesis, deforestation and development has decreased their overall capacity to restore oxygen levels.

As nations attempt to curb emissions and divest from fossil fuels, Dr. Huang feels there should also be an increased focus on carbon capture and re-use to minimize the harmful impact of increased atmospheric CO₂.

“The current global commitment to cut carbon emissions by 30 percent by 2030 is an enormous challenge, and one that will be difficult to achieve given that energy needs are accelerating,” said Professor Huang.

Carbon capture technologies have been around for over 10 years. However, they require carbon to being held in deep underground chambers.

“Carbon conversion could be a financially viable alternative as it would allow for the generation of industrial quantities of materials, such as methanol, which is a useful material for production of fuels and other chemicals,” he concluded.

DISCLOSURE

Professor Jun Huang’s research is supported by the Australian Research Council (DP180104010, the Sydney Research Accelerator Prizes (SOAR) and the University of Sydney Nano Institute Grand Challenge program.

The paper was authored by Dr Haitao Li, Dr Yadan Deng, Dr Youdi Liu, Dr Xin Zeng, Professor Dianne Wiley and Professor Jun Huang.

Australia wants to build a giant underground ‘battery’ to help power the nation – ‘Hydro Down Under’

The power down under. Image: REUTERS/Action Images

Governments around the world are looking to boost renewable energy capacity as they race to cut their reliance on fossil fuels. But one of the big questions they face is how to keep the lights on when the sun isn’t shining or the wind isn’t blowing.

Australia’s answer is to build a giant underground hydropower plant beneath a national park.

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The $3.1 billion Snowy 2.0 project – so called because it’s located in the Snowy Mountains in New South Wales – will use water flowing between two reservoirs to generate 10% of the nation’s energy needs at peak times and when renewables are offline.

Image: Snowy Hydro

Water will stream through 27 kilometres of tunnels from the Tantangara Dam to the Talbingo Reservoir 700 metres below, while passing through a power plant 1 kilometre beneath the surface. The turbines will be reversible so they can pump the water back uphill when demand is low, using wind energy.

Known as a pumped hydro scheme, the project is designed to work like a giant battery – storing water energy that can be released as electricity to the grid with a notice of just 90 seconds. It’s hoped the plant will provide energy storage of 175 hours, enough to power 3 million homes for a week.

“Snowy 2.0 will provide the storage and on-demand generation needed to balance the growth of wind and solar power and the retirement of Australia’s ageing fleet of thermal power stations,” says Snowy Hydro Chief Executive Paul Broad. “In short, it will keep our energy system secure and keep the lights on.”

The first power produced from Snowy 2.0 is expected to flow into the national grid in late 2024.

Image: Snowy Hydro

A sensitive issue

The project is controversial, not least because of its planned location – the Kosciuszko National Park. Named after the nation’s highest mainland peak, the 2,228 metre Mount Kosciuszko, the park is a UNESCO Biosphere Reserve.

Critics question the reliability of the project’s cost estimates and its ability to fulfil its claimed potential output. They say it is unlikely to be finished on time and ask if the money would be better spent on conventional battery storage.

Environmental groups say the project will create 9 million cubic metres of tunnelling waste, and claim that dumping it in an ecologically sensitive landscape would be “environmental vandalism”.

Snowy Hydro, the company behind the project, refutes these claims and says it will deliver on time and to budget. It says any environmental impact will be limited to just 100 hectares of the 674,000 hectare park – and the project is expected to create 5,000 new jobs.

Hydro upgrade

Snowy Hydro 2.0 builds on the original Snowy Hydro project, which marks its 70th anniversary this year. It grew out of a scheme to alleviate the effects of droughts in the continent’s interior by storing water from the Murray, Murrumbidgee, Snowy and Tumut rivers.

Work began on the first Snowy Mountains hydroelectric scheme in 1949. The $564 million project was completed in 1974 and includes seven power stations, 16 major dams, 145 kilometres of interconnected tunnels and 80 kilometres of aqueducts.

The government says the new project is essential to Australia’s transition to renewable energy sources. Currently, almost two-thirds of the country’s electricity is generated by coal-fired plants. Together I coal and gas account for 85% of the nation’s power generation. 

The government has set a target of increasing the contribution of renewables to 23.5% by the end of next year.

The latest Fostering Effective Energy Transition report from the World Economic Forum ranks Australia 43rd out of 115 countries in terms of the performance of its energy system and its readiness for transition to clean energy.

Rice University: Li-Ion Components for High-Temperature Aerospace, Industrial Apps

A toothpaste-like composite with hexagonal boron nitride developed by researchers at Rice University is an effective electrolyte and separator in lithium-ion batteries intended for high-temperature applications in a number of industries, including aerospace and oil and gas. (Source: Jeff Fitlow/Rice University)

One major and dangerous problem with lithium-ion batteries is that they can catch fire when heated to high temperatures, an issue that has caused damage and even death when devices ignited without warning.

Now researchers at Rice University have come up with a solution to this very serious safety problem in the form of a combined electrolyte and separator for rechargeable lithium-ion batteries that supplies energy at usable voltages and in high temperatures. The material is a toothpaste-like composite that is capable of performing well at and withstanding high temperatures without combusting.

The problem with most current lithium-battery chemistries is that they present safety concerns when heated beyond 50C (122F) due to the electrolyte/separator combination used in them, explained Marco-Tulio Rodrigues, a Rice graduate student and one of the authors of a paper on the research published in Advanced Materials Science.

 

“The separator is usually a thin polymer film and may deform at high temperatures, causing a short circuit,” Rodrigues told Design News. “The electrolytes are based on organic solvents, which tend to boil at high temperatures, increasing the internal pressure of the cell. Although commercial batteries implement some protection mechanisms to avoid these problems, any damages to the cell case may potentially lead to ignition, since the electrolyte is also highly flammable.”

 

The work of the Rice team addresses both the issue of developing a separator that will not cause a short circuit and an electrolyte that doesn’t have the tendency to catch fire, he said.

The batteries made with the components they developed functioned as intended in temperatures of 50C (122F) for more than a month without losing efficiency, according to researchers. Moreover, test batteries consistently operated from room temperature to 150C (302F), setting one of the widest temperature ranges ever reported for such devices, they said.

To solve the electrolyte problem, researchers used solutions based on ionic liquids in the electrolytes, which have largely been proposed as substitutes for organic solvents in the electrolyte of lithium-ion batteries because they present a much higher thermal stability, Rodrigues explained.

“These chemicals are basically special salts with a very low melting point, in such a way that they are liquid at room temperatures,” he said. “They are completely nonflammable and they do not evaporate at all until they decompose, which occurs beyond 350C (662F).”

With the electrolyte situation solved, researchers turned their attention to finding a new separator, which they addressed with a material called hexagonal boron nitride, also known as white graphene.