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Brookhaven and Forge Nano to Mature Noble Gas-Trapping Technology

Posted By Graphene Council, Friday, July 10, 2020
A research proposal submitted by the Center for Functional Nanomaterials (CFN) and Nuclear Science and Technology (NST) Department at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, with the startup Forge Nano as a partner, has been selected as a 2020 Technology Commercialization Fund (TCF) project. Of the 82 technologies selected from among more than 220 applications, three were developed at Brookhaven Lab. This TCF funding is the first to be awarded to the CFN, where the technology was developed.

The DOE Office of Technology Transitions manages the TCF program, which was created by the Energy Policy Act of 2005 to promote promising energy technologies developed at DOE national labs. Federal funding awarded through the TCF is matched with nonfederal contributions by private partners interested in commercializing the technology. The goal of the TCF is to advance the commercialization of these technologies and strengthen lab-private sector partnerships to deploy them to the marketplace.  

The project that Brookhaven Lab and Forge Nano scientists will partner on is called “Maturation of Technology for Trapping Xenon and Krypton.”

Xenon (Xe) and krypton (Kr) are two noble gases produced during nuclear fission—a reaction in which the nucleus of an atom splits into two or more smaller, lighter nuclei—inside nuclear reactors. These gases can decrease the amount of energy extracted from a nuclear fuel source by increasing the pressure in the fuel rod (the sealed tubes that contain fissionable material) and reduce fuel rod lifetime. Moreover, radioactive isotopes of Xe and Kr can become trapped in unreacted fuel, which requires disposal. Therefore, capturing and removing Xe and Kr could improve the energy-generation efficiency of nuclear reactors and reduce radioactive waste.

For several years, scientists in the NST Department have been exploring various candidate materials—including microporous carbon and porous metal-organic frameworks—to absorb these fission gases, thereby reducing pressure buildup in fuel rods. Separately, scientists at the CFN have been developing 2-D porous, cage-like frameworks made of ultrathin—less than a single nanometer—inorganic silica (silicon and oxygen) and aluminosilicate (aluminum, silicon, and oxygen) films supported on metal surfaces. In 2017, they became the first team to trap a noble gas inside a 2-D porous structure at room temperature. Last year, they discovered the mechanism by which these “nanocages” trap and separate single atoms of argon (Ar), Kr, and Xe at room temperature. Following these studies, the CFN submitted an invention disclosure on the silicate materials for trapping gases (among other applications) to Brookhaven’s Intellectual Property Legal Group, which together with Brookhaven’s Office of Technology Transfer, helped the team explore promising applications and connected CFN and NST scientists.

“Trapping single atoms of noble gases at noncryogenic temperatures is extremely difficult and a relevant challenge for nuclear waste remediation, among other industrial applications,” said CFN Interface Science and Catalysis Group materials scientist Anibal Boscoboinik, who has been leading the work. “This difficulty is primarily due to the weak interaction of noble gases in their neutral state. The approach developed at the CFN enables trapping of the noble gas atoms in cages via ionization—converting them to electrically charged atoms, or ions—for a very brief time so they can enter the cages. Once they are inside, they go back to their neutral, stable state, but by that time they are already physically confined in the cages.”  

Now, through the TCF, Brookhaven will partner with Forge Nano to scale up the manufacture of the lab-demonstrated nanocages to maximize the surface area for trapping Kr and Xe atoms. One possible way to achieve this optimization is to place the nanoporous materials inside larger (mesoporous) materials—in other words, a cage within a cage. Forge Nano will apply its expertise in atomic layer deposition—a technique for depositing one atom at a time onto a surface material until a complete layer is formed—for precision nanocoatings to coat the inside of the mesopores with nanocages, where the trapping will occur.

“This innovative material application is a perfect match for us at Forge Nano for coating atomically thin controlled coatings,” said project partner Staci Moulton, the application engineer for business development at Forge Nano. “We are excited to work with CFN researchers to scale up their breakthrough.”

Using ion beams and test reactors at Texas A&M University’s Nuclear Engineering and Science Center and Accelerator Laboratory—one of the partner facilities accessible through the Nuclear Science User Facilities—the Brookhaven team will test the radiation stability of the materials at levels relevant to nuclear fission reactor environments.

“The radiation damage testing capabilities available at Texas A&M will greatly accelerate our ability to construct robust materials,” said NST Department Chair Lynne Ecker.

“Research in our group focuses on understanding at a fundamental level the physicochemical processes that happen on functional surfaces and interfaces exposed to chemicals,” said CFN Interface Science and Catalysis Group Leader Dario Stacchiola. “To probe these processes in real time and under operating conditions, we develop and operate state-of-the-art in situ and operando tools.”

To follow the trapping of the gases, they will perform x-ray photoelectron spectroscopy (XPS), a technique for identifying and quantifying the elements on a sample’s surface. These studies will be conducted using ambient-pressure (AP) XPS instruments located in the CFN Proximal Probes Facility and at the In situ and Operando Soft X-ray Spectroscopy (IOS) beamline of Brookhaven’s National Synchrotron Light Source II (NSLS-II).

If successful, this technology—which Brookhaven’s Intellectual Property Legal Group recently submitted a provisional patent application for—would have a major impact on the nuclear power industry and environment at large. As of 2018, nearly 450 nuclear reactors were generating electricity, equivalent to 10 percent of the global electricity supply. Nuclear power is the second largest source of low-carbon electricity (hydropower is the first).

“The nanocages can be transformative in the field of nuclear power generation by improving the efficiency and reliability of nuclear reactors and reducing radioactive waste and emission,” said Boscoboinik.

“A technology to more efficiently trap, separate, and sequester noble gases has applications in advanced nuclear reactors,” added Ecker. “The nanocages have the potential to become an enabling technology for future reactors. We’re very excited to explore this possibility by working with our partner, Forge Nano.”

Tags:  Anibal Boscoboinik  Arrelaine Dameron  Brookhaven National Laboratory  Center for Functional Nanomaterials  Dario Stacchiola  David King  Forge Nano  Graphene  Graphite  Lynne Ecker  Nuclear Science and Technology (NST) Department  Staci Moulton  U.S. Department of Energy 

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ZEN GRAPHENE SOLUTIONS LTD. COMPLETES NON-BROKERED PRIVATE PLACEMENT OF UNITS

Posted By Graphene Council, Wednesday, July 8, 2020
Zen Graphene Solutions Ltd. (“Zen Graphene” or the “Company”) (TSXV:ZEN) is pleased to announce the closing of the second tranche, comprised of 1,621,175 units, of its previously announced private placement of units (the “Offering”). The Company raised total gross proceeds of $2,049,999.80 under the Offering, which will be used to fund ongoing work on the Albany Graphite Project including graphene research and scale up, COVID-19 initiatives and other graphene applications development and for general corporate purposes. The Board of directors wishes to thank all the long-term shareholders and new shareholders who participated in the Offering.

Francis Dubé, CEO commented: “With this private placement now completed, the company is in a strong financial position to accelerate the many research and development projects it has underway and explore new opportunities that are being considered.”

The total Offering consisted of the issuance of 3,416,666 units (“Units”) at a price of $0.60 per Unit, for aggregate gross proceeds of $2,049,999.80. Each Unit consisted of one common share of the Company (“Common Share”) and one half of one non-transferable share purchase warrant (“Warrant”). Each whole Warrant will entitle the holder thereof to acquire one additional Common Share at an exercise price of $0.80 per Warrant, exercisable for a period of twenty-four months from the closing of the Offering (the “Exercise Period”).

All Warrants issued in connection with the Offering are subject to an acceleration clause. If the Company’s share price trades at or above $1.00 per share for a period of ten (10) consecutive trading days during the Exercise Period, the Company may accelerate the expiry date of the Warrants to 30 calendar days from the date on which written notice is given by the Company to the holders of the Warrants.
The Common Shares and the Warrants issued in connection with the second tranche of the Offering will be subject to a hold period until November 7, 2020 in accordance with applicable securities laws.

Tags:  COVID-19  Francis Dube  Graphene  Graphite  Healthcare  ZEN Graphene Solutions 

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Leading Edge Materials To Participate In Graphite And Graphene Anode Research Project

Posted By Graphene Council, Thursday, July 2, 2020
Leading Edge Materials announces the participation of its subsidiary Woxna Graphite AB in the newly launched research project “Graphite and graphene as battery electrodes” (the “Project”) which is part of the Vinnova funded competence centre Batteries Sweden (“BASE”).

The Project will research the utilization of natural graphite for battery applications through determination of functionality of the natural graphite in batteries, the addition of silicon to the graphite particles, long-term stability and characterization and optimization of the surface chemistry. The latter will look at innovative technologies for tailoring of the surface chemistry by for example surface coatings, covalent functionalization and artificial Solid Electrolyte Interphases.

BASE was created as an alliance for ultrahigh performance batteries with a long-term vision to address the energy storage challenges associated with the transition to a fossil-free society by developing new types of lightweight, inexpensive, sustainable and safe ultra-high-energy storage batteries. The competence centre, coordinated by the Ångström Laboratory and the renowned battery scientist Professor Kristina Edström at Uppsala University, was granted SEK 34,000,000 in funding by the Swedish governmental innovation agency Vinnova. The partners of BASE are leading Swedish academic institutions and industrial companies spanning the battery value chain; Uppsala University, Chalmers University of Technology, KTH Royal Institute of Technology, RISE Research Institutes of Sweden, ABB, Volvo, Altris, Comsol, Graphmatech, Insplorion, Northvolt, SAFT, Scania, Stena Recycling, Volvo Cars and Woxna Graphite. (https://www.batteriessweden.se/)

Filip Kozlowski, CEO states “Being part of this project is a great opportunity for Woxna Graphite to contribute to the long-term vision of the Batteries Sweden alliance. Being able to supply natural graphite from Sweden could enable sustainable high-performance battery materials of the future. One of the focus areas, surface modification of spherical purified natural graphite is a key area of innovation to enable improved performance and cycle life for lithium-ion battery anodes.”

Woxna Graphite AB is the owner of one of the western world’s few permitted and fully built graphite mines, located in central Sweden near the town of Edsbyn. The Woxna graphite mine and production facility is comprised of four graphite deposits each with a mining lease, an open pit mine, a processing plant and tailings dam, located close to the town of Edsbyn, Sweden.  Due to market conditions for traditional graphite markets the operation has been kept on a production-ready basis. Ongoing development is directed towards test work focused on the possible production and modification of high purity graphite using thermal purification technologies for emerging high growth high value markets, one such example being the lithium-ion battery industry.  Other potential high-value end-markets being investigated are purified micronized graphite for metallurgical and electroconductive additives and purified large flake graphite as a precursor for the production of expandable graphite suitable as a feed for graphite foils and fuel cell bipolar plates. The purification and modification of natural graphite is very energy intensive and having access to low cost low carbon footprint hydropower offers the potential to become a market leader in terms of sustainability.

Tags:  Batteries  Filip Kozlowski  Graphene  Graphite  Leading Edge Materials  Woxna Graphite AB 

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ZEN GRAPHENE SOLUTIONS LTD. COMPLETES FIRST TRANCHE OF NON-BROKERED PRIVATE PLACEMENT OF UNITS

Posted By Graphene Council, Wednesday, July 1, 2020
Zen Graphene Solutions Ltd. is pleased to announce the closing of the first tranche of its previously announced private placement of units (the “Offering”). The Company raised gross proceeds of $1,077,294.80 under the Offering, which will be used to fund ongoing work on the Albany Graphite Project including graphene research and scale up, COVID-19 initiatives and other graphene applications development and for general corporate purposes. A second tranche is expected to close shortly in line with previous interest received and reported in the news release of June 17th 2020. The Board of directors wishes to thank all the long-term shareholders and new shareholders who participated in the Offering.

The Offering consisted of the issuance of 1,795,491 units (“Units”) at a price of $0.60 per Unit, for aggregate gross proceeds of $1,077,294.80. Each Unit consisted of one common share of the Company (“Common Share”) and one half of one non-transferable share purchase warrant (“Warrant”). Each whole Warrant will entitle the holder thereof to acquire one additional Common Share at an exercise price of $0.80 per Warrant, exercisable for a period of twenty-four months from the closing of the Offering (the “Exercise Period”).

All Warrants issued in connection with the Offering are subject to an acceleration clause. If the Company’s share price trades at or above $1.00 per share for a period of ten (10) consecutive trading days during the Exercise Period, the Company may accelerate the expiry date of the Warrants to 30 calendar days from the date on which written notice is given by the Company to the holders of the Warrants. The Common Shares and the Warrants issued in connection with the Offering will be subject to a hold period until October 27, 2020 in accordance with applicable securities laws.

Tags:  Graphene  Graphite  ZEN Graphene Solutions 

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Talga Looks to Expand Battery Anode Capacity

Posted By Graphene Council, Wednesday, June 24, 2020
Battery  anode  company Talga  Resources  Ltd is  pleased  to provide an update on the development of the Vittangi Anode Project in northern Sweden.   As part of this  on-going  development  the  Company  is  engaging  directly  with  lithium-ion  (“Li-ion”)  battery manufacturers towards purchase agreements for its planned anode production.

Commercial   samples   of   Talnode-C,   and   in   some   cases   Talnode-Si,   are   progressing   through confidential  qualification  processes  under  36  active  customer  engagements.  These  include  the majority of announced Li-ion battery manufacturers in Europe (see Figure 1) and six of the world’s major automotive OEMs.

Expressions of Interest received by engaged parties for supply of Talnode-C in 2023 exceeds three times the annual production capacity proposed in the Company’s Pre-feasibility Study1. As a result of this  interest,  Talga  is  expanding  the  Niska  Scoping  Study  underway  to  evaluate  significantly  larger anode production options for the overall Vittangi Project.

Commenting on the Company’s progress, Talga Managing Director Mark Thompson said: “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.     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.”

Planning for expansion of anode production – Niska scoping study

Based on the strong interest from industry and the anticipated permitting timeframes in Sweden, the  Company  has  decided  to  expand  the  Niska  scoping  study  of  the  Vittangi  Project  to  review significantly  larger  anode  production  options.  The  outcomes  will  be  in  addition  to  the  current Nunasvaara South PFS production plan of 19,000 tpa*.

This  scoping  study  is  underway  on Talga’s  three  Vittangi  graphite  resources  not  currently  in  the PFS; Nunasvaara North, Niska South and Niska North (“Niska Scoping Study”), all located within approximately  2.5km  kilometres  north  of  Nunasvaara  South  (see  Figure  2).    Collectively  these JORC  resources  total  6.5  million  tonnes  at  26.8%Cg  (see  Table  1),  including  a  higher  grade resource domain at Nunasvaara North of 900,000 tonnes at 33.0%Cg (see Table 2).

A  mining  study  supporting  the  larger  scale  project  has  been  completed,  and  metallurgical  and battery  product  testwork  on  composite  samples  is  underway.  Due  to  the  significant  increase  in scale, the Company is targeting completion of the Niska Scoping Study in Q3 2020.

Li-ion anode market growth

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. This will require >2,500,000 tpa of graphite anode, up from ~450,000 tpa anode production today. Europe  is  the  world’s  fastest  growing  region  for  Li-ion  battery  manufacturing  and  will  require
500,000 tpa of new graphite anode supply by 2029.2

While the COVID-19 outbreak in 2020 has severely impacted electric vehicle (“EV”) sales in the short  term,  Bloomberg  New  Energy  Finance  data3  shows  EV  sales  hold  up  better  than  internal combustion engine vehicles due to new (lower cost) models and supportive government policies.

In the quarters prior to the COVID-19 outbreak EV sales as % of total passenger vehicles rose rapidly  in  the  EU,  with  Germany  and  France  recording  increases  of  100%  during  the  period4. 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 countries5.

Competent Persons Statement

The Niska Mineral Resource estimate was first reported in the Company’s announcement dated 15 October  2019  titled  ‘Talga  Substantially  Increases  Flagship  Graphite  Resource  Size,  Grade  and Status’. The Company confirms that it is not aware of any new information or data that materially affects  the  information  included  in  the  previous  market  announcement  and  that  all  material assumptions and technical parameters underpinning the Resource estimate in the previous market announcement continue to apply and have not materially changed.

The Nunasvaara Mineral Resource estimate was first reported in the Company’s announcement dated 27 April 2017 titled ‘Talga boosts Swedish graphite project with maiden Niska resource’. The Company confirms that it is not aware of any new information or data that materially affects the information included in the previous market announcement and that all material assumptions and technical parameters underpinning the Resource estimate in the previous market announcement continue to apply and have not materially changed.

The Nunasvaara Ore Reserve statement was first reported in the Company’s announcement dated 23 May 2019 titled ‘Outstanding PFS results support Vittangi graphite development’. The Company confirms that it is not aware of any new information or data that materially affects the information included  in  the  previous  market  announcement  and  that  all  material  assumptions  and  technical parameters underpinning the Reserve estimate in the previous market announcement continue to apply and have not materially changed.

Tags:  Automotive  Battery  Graphene  Graphite  Li-ion Batteries  Mark Thompson  Talga Resources 

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Vittangi Project Supported by National Interest Demarcation

Posted By Graphene Council, Thursday, June 18, 2020
Battery anode and graphene additives company Talga Resources Ltd is pleased to advise of positive developments at its 100% owned Vittangi graphite project in northern Sweden (“Vittangi”).

A recent decision by the Swedish Geological Survey (“SGU”) completed the demarcation of Vittangi as a mineral deposit of national interest1. This designation adds support to consider the exploitation of Vittangi as a mineral deposit when government authorities review development plans and any potential competing land uses.

Under the Swedish Environmental Code, deposits of valuable substances or materials can be defined as being of national interest, meaning municipalities and central government agencies may not authorise activities that might prevent or significantly hinder exploitation of the mineral deposit. The national interest area covers the entirety of Talga’s currently defined Vittangi graphite resources (see Table 1 below), and undrilled extensional deposits, as detailed in Figure 1.

The SGU noted the Vittangi graphite deposit's significance to the country's supply capacity and its special material properties and concluded the deposit constitutes a unique natural asset of valuable substances or materials.

Further, they consider locally produced graphite could help strengthen the competitiveness of the Swedish battery manufacturing industry and that, as the known highest grade graphite deposit in the world, Vittangi could “meet a great need not only within Sweden but internationally”.
The decision2 takes note of the European Commission’s listing of graphite as a critical raw material and their warning that a lack of access to such critical commodities could slow the development of fossil-free energy sources.

Commenting on SGU’s decision, Talga Managing Director Mark Thompson said: "We welcome SGU’s decision as a positive and timely development following Talga’s recent lodgement of the Vittangi Graphite Project mining permit applications, towards becoming Europe’s first vertically integrated producer of Li-ion battery active anode material."

SGU Decision Background
In preparing the demarcation SGU obtained extensive information on the Vittangi Graphite Project including details relating to its geology and material properties. The demarcation defines the boundaries of the original declaration of Nunasvaara as a deposit of national interest which contained only a centre co-ordinate. Results from Talga’s extensive exploration work were made available during the investigation and SGU carried out their own detailed electromagnetic survey to assist in the demarcation, which covers approximately 20km strike of graphite mineralisation.

Competent Persons Statement
The Nunasvaara Mineral Resource estimate was first reported in the Company’s announcement dated 27 April 2017 titled ‘Talga Substantially Increases Flagship Graphite Resource Size, Grade and Status’. The Company confirms that it is not aware of any new information or data that materially affects the information included in the previous market announcement and that all material assumptions and technical parameters underpinning the Resource estimate in the previous market announcement continue to apply and have not materially changed.

The Niska Mineral Resource estimate was first reported in the Company’s announcement dated 15 October 2019 titled ‘Talga boosts Swedish graphite project with maiden Niska resource’. The Company confirms that it is not aware of any new information or data that materially affects the information included in the previous market announcement and that all material assumptions and technical parameters underpinning the Resource estimate in the previous market announcement continue to apply and have not materially changed.

Tags:  Graphene  Graphite  Mark Thompson  Talga Resources 

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ZEN Graphene Solutions Ltd. Reports on Expressions of Interest for Non-Brokered Private Placements of Units

Posted By Graphene Council, Thursday, June 18, 2020
ZEN Graphene Solutions Ltd. is pleased to announce it has received expression of interest from investors in an amount of $1,777,000 for the non-brokered private placement announced on June 15, 2020. These expressions of interest have far exceeded management’s expectation and, subject to TSX Venture Exchange approval, the Company is working diligently to complete the Offering. Management believes that this highlights the progress ZEN has made in becoming an advanced materials graphene company. Following completion of the Offering, ZEN’s cash balance will exceed any balance in recent years thereby ensuring the Company can continue executing its business plan during the COVID-19 pandemic. A subsequent news release will be issued concurrently with the closing of the Offering.

The proceeds of the Offering will be used to fund ongoing work on the Albany Graphite Project including: Graphene research and scale up, COVID-19 initiatives and other graphene application development, and general corporate purposes. All securities issued to purchasers under the Offering will be subject to a four-month hold period from the closing date of the Offering, pursuant to applicable securities legislation and policies of the Exchange. Finders’ fees may be paid, as permitted by Exchange policies and applicable securities law.

Tags:  Graphene  Graphite  ZEN Graphene Solutions 

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A touch of gold and silver

Posted By Graphene Council, Saturday, June 6, 2020

Metals are usually characterized by good electrical conductivity. This applies in particular to gold and silver. However, researchers from the Max Planck Institute for Solid State Research in Stuttgart, together with partners in Pisa and Lund, have now discovered that some precious metals lose this property if they are thin enough. The extreme of a layer only one atom thick thus behaves like a semiconductor. This once again demonstrates that electrons behave differently in the two-dimensional layer of a material than in three-dimensional structures. The new properties could potentially lead to applications, for example in microelectronics and sensor technology.

One might think that gold leaf, which is only 0.1 µm thick, is actually quite thin. Far from it. It can actually be several hundred times thinner. For example, the research team of Ulrich Starke and his former doctoral student Stiven Forti have successfully created a gold layer only a single atom thick. Two-dimensional gold, so to speak.

Starke is head of the Interface Analysis Facility at the Max Planck Institute for Solid State Research in Stuttgart. His team has long been working on the border between three-dimensional (voluminous) and two-dimensional (planar) materials. Solid state researchers are interested in this transition because it is associated with changes in certain material properties. This has previously been demonstrated in two-dimensional carbon, or graphene. Among other things, its electrons are significantly more mobile and allow the electrical conductivity to increase to 30 times that of the related three-dimensional graphite.

Gold atoms are pushed between graphene and silicon carbide

However, for many metals, producing layers of material just one atom thick is not an easy task. “With classical deposition methods, gold atoms, for example, would immediately agglomerate into three-dimensional clusters”, explains Starke. His team is therefore working with a different method – intercalation – on which they did pioneering work around 10 years ago. Intercalation literally means sliding something in between. And that is precisely how it works. The researchers start with a silicon carbide wafer. Using a process they developed themselves, they first convert its surface into a single-atomic layer of graphene. “If we vaporise sublimated gold on to this silicon carbide-graphene arrangement in a high vacuum, the gold atoms migrate between the carbide and the graphene”, explains Forti. The former Max Planck doctoral candidate is now doing research at the Center for Nanotechnology Innovation in Pisa. It is not yet fully understood how the thick gold atoms get into the interstitial space. But this much is clear: higher temperatures favour the process.

The team had also applied the intercalation technique to other elements, including germanium, copper, and gadolinium. Yet, according to Forti, the main focus was the influence on the properties of graphene. In the case of gold, however, it was found for the first time that the intercalated atoms arranged themselves in a regular, periodically recurring two-dimensional structure – crystalline – along the silicon carbide surface. “If the intercalation is carried out at 600°C, the graphene layer prevents the gold atoms from agglomerating to form drops”, says Forti about the function of the carbon layer in the sandwich structure.

A gold layer consisting of only two atomic layers conducts like a metal
The successful preparation of the gold layer of one atom thickness was only the first step. Subsequently, the extremely thin materials and their possibly special characteristics became interesting for the researchers. They could indeed show that the extremely thin layer of gold develops its own electronic – and semiconductor – properties. To compare: the electrical conductivity of voluminous (i.e. three-dimensional gold) is nearly as good as that of copper. Because theoretical considerations forecast a metallic character for pure 2D gold, the semiconductor finding was somewhat surprising. “Interactions between the gold atoms and either the silicon carbide or the graphene carbon obviously still play a role here. This influences the energy levels of the electrons”, says Starke.

Semiconductors are essential materials in microelectronics and other fields. For example, electronic switching elements such as diodes or transistors are based on it. Starke’s team can envisage some typical semiconductor applications for the new 2D material. A second layer of gold atoms again gives a metallic character – and thus influences the electrical conductivity. “By varying the amount of sublimated gold, we can tightly control whether one or two layers of gold form”, explains Forti.

It would therefore be conceivable to use components with alternating single- or double-atomic gold layers. The new manufacturing method would then have to be suitably combined with common lithographic methods of chip production. For example, diodes significantly smaller than conventional ones could be produced. According to Starke, the different electronic states of single and double-layer gold could also be used in optical sensors.

Electronic effects also in the graphene layer

Another application idea results from effects caused by the intercalated gold in the adjacent graphene layer, which apparently depend on the thickness of the gold. “A gold layer one atom thick causes an n-doping in the graphene. This means we obtain electrons as charge carriers”, says Forti. In spots where the gold is two atomic layers thick, exactly the opposite – p-doping – happens. There, missing electrons or positively charged so-called “holes” act as charge carriers. The gold also enhances the interaction of plasmons (i.e. fluctuations in the density of charge carriers) with electromagnetic radiation. “A structured, alternating arrangement of n- and p-doping in the graphene could thus be used. For example, as a highly sensitive yet high-resolution detector array for terahertz radiation like those used in materials testing, for security checks at airports, or for wireless data transmission”, says Starke.

Starke’s team has already taken the next step in the production of two-dimensional precious metal layers. Also in an intercalation experiment with silver, a strictly crystalline two-dimensional silver layer formed between silicon carbide and graphene. And what’s more: even this metal, which is usually an even better electrical conductor than gold, becomes a semiconductor when reduced to two dimensions. The initial results indicate that the energy required to make the silver layer electrically conductive is probably higher than for 2D gold. “The semiconductor properties of a component made from this material might therefore be thermally more stable than those of gold”, says Starke about possible practical consequences.

Tags:  2D materials  Graphene  Graphite  Max Planck Institute for Solid State Research  Sensors  Stiven Forti  Ulrich Starke 

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Skoltech scientists get a sneak peek of a key process in battery 'life'

Posted By Graphene Council, Friday, May 29, 2020
Researchers from the Skoltech Center for Energy Science and Technology (CEST) visualized the formation of a solid electrolyte interphase on battery-grade carbonaceous electrode materials using in situ atomic force microscopy (AFM). This will help researchers design and build batteries with higher performance and durability.

A solid electrolyte interphase (SEI) is a thin layer of electrolyte reduction products formed on the surface of a lithium-ion battery anode during several initial cycles. It prevents further electrolyte decomposition, stabilizing the electrode/electrolyte interface, and ensures a long battery life. Forming a SEI film takes time and energy, and its quality largely governs battery performance and durability: a poorly formed SEI results in rapid degradation of battery performance.

Still, the formation of SEI remains poorly understood, and scientists use in situ atomic force microscopy that allows direct observation of this process. Until now, most of these measurements were carried out on Highly Oriented Pyrolytic Graphite (HOPG), a very pure and ordered form of graphite which has a clean and atomically flat basal plane surface. However, HOPG is a poor replacement for actual battery-grade electrode materials, so the process is significantly different from what happens inside a commercial battery.

A Skoltech team led by research scientist Sergey Luchkin and professor Keith Stevenson succeeded in visualization of SEI formation on battery-grade materials. For this, they had to design an electrochemical cell that allowed the measurements necessary for this direct observation of SEI formation.

"Battery-grade materials are powders, and visualizing dynamic processes on their surface by AFM, especially in liquid environment, is challenging. A standard battery electrode is too rough for such measurements, and isolated particles tend to detach from substrate during scanning. To overcome this issue, we embedded the particles into epoxy resin and made a cross section, so the particles were firmly fixed in the substrate," says Luchkin.

The researchers found that the SEI on battery-grade materials nucleated at different potential than that on HOPG. It was also more than two times thicker and mechanically stronger. Finally, they were able to demonstrate that SEI was better bound with the rough surface of battery-grade graphite than with the flat surface of HOPG.

"Spatially-resolved investigations of battery interfaces and interphases detailed in this work provide significant new insights into the structure and evolution of the anode SEI. Therefore, they provide firm guidelines for rational electrolyte design to enable high performance batteries with improved safety," adds Stevenson.

Tags:  Battery  Graphene  Graphite  Keith Stevenson  Sergey Luchkin  Skoltech Center for Energy Science and Technology 

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AMD's truly “Green RFID” solution continues to advance towards market deployment

Posted By Graphene Council, Friday, May 29, 2020
Advanced Material Development is pleased to be associated with the publication of a research paper in the prestigious scientific journal Advanced Material Technology. The paper “Large-Scale Surfactant Exfoliation of Graphene and Conductivity-Optimized Graphite Enabling Wireless Connectivity” describes some of the previous research by its Universities of Sussex and Surrey teams into the developments of AMD’s proprietary “Conductively Optimized Graphite” (COG) nano-material.

This report highlights the success of the early stage prototype in achieving read distances in excess of 2M in lab conditions with theoretical ranges beyond 11M. Ongoing work in the Sussex labs continues to improve the print qualities of the conductive ink for commercial production needs.

AMD maintains full ownership of all critical and underlying IP and is holding talks with a number of potential global partners in the fast-growing RFID industry to further develop and deploy this Green RFID solution.

We are also pleased to note that the Sussex team are back in the labs following shutdown and hence work has been disrupted only marginally.

Tags:  Advanced Material Development  Advanced Material Technology  Graphene  Graphite  RFID  Universities of Sussex 

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