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How to make perfect edges in 2D-materials

Posted By Terrance Barkan, Tuesday, October 20, 2020
Ultrathin materials such as graphene promise a revolution in nanoscience and technology. Researchers at Chalmers University of Technology, Sweden, have now made an important advance within the field. In a recent paper in Nature Communications they present a method for controlling the edges of two-dimensional materials using a ‘magic’ chemical. 

“Our method makes it possible to control the edges – atom by atom – in a way that is both easy and scalable, using only mild heating together with abundant, environmentally friendly chemicals, such as hydrogen peroxide,” says Battulga Munkhbat, a postdoctoral researcher at the Department of Physics at Chalmers University of Technology, and first author of the paper. 

Materials as thin as just a single atomic layer are known as two-dimensional, or 2D, materials. The most well-known example is graphene, as well molybdenum disulphide, its semiconductor analogue. Future developments within the field could benefit from studying one particular characteristic inherent to such materials – their edges.

Controlling the edges is a challenging scientific problem, because they are very different in comparison to the main body of a 2D material. For example, a specific type of edge found in transition metal dichalcogenides (known as TMD’s, such as the aforementioned molybdenum disulphide), can have magnetic and catalytic properties. 

Typical TMD materials have edges which can exist in two distinct variants, known as zigzag or armchair. These alternatives are so different that their physical and chemical properties are not at all alike. For instance, calculations predict that zigzag edges are metallic and ferromagnetic, whereas armchair edges are semiconducting and non-magnetic. Similar to these remarkable variations in physical properties, one could expect that chemical properties of zigzag and armchair edges are also very different. If so, it could be possible that certain chemicals might ‘dissolve’ armchair edges, while leaving zigzag ones unaffected. 

Now, such a ‘magic’ chemical is exactly what the Chalmers researchers have found – in the form of ordinary hydrogen peroxide. At first, the researchers were completely surprised by the new results. 

“It was not only that one type of edge was dominant over the others, but also that the resulting edges were extremely sharp – nearly atomically sharp. This indicates that the ‘magic’ chemical operates in a so-called self-limiting manner, removing unwanted material atom-by-atom, eventually resulting in edges at the atomically sharp limit. The resulting patterns followed the crystallographic orientation of the original TMD material, producing beautiful, atomically sharp hexagonal nanostructures,” says Battulga Munkhbat.

The new method, which includes a combination of standard top-down lithographic methods with a new anisotropic wet etching process, therefore makes it possible to create perfect edges in two-dimensional materials.

“This method opens up new and unprecedented possibilities for van der Waals materials (layered 2D materials). We can now combine edge physics with 2D physics in one single material. It is an extremely fascinating development,” says Timur Shegai, Associate Professor at the Department of Physics at Chalmers and leader of the research project. 

These and other related materials often attract significant research attention, as they enable crucial advances within in nanoscience and technology, with potential applications ranging from quantum electronics to new types of nano-devices. These hopes are manifested in the Graphene Flagship, Europe’s biggest ever research initiative, which is coordinated by Chalmers University of Technology. 

To make the new technology available to research laboratories and high-tech companies, the researchers have founded a start-up company that offers high quality atomically sharp TMD materials. The researchers also plan to further develop applications for these atomically sharp metamaterials.

Tags:  2D materials  Battulga Munkhbat  Chalmers University of Technology  Graphene  Graphene Flagship  nanomaterials  semiconductor  Timur Shegai 

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Talga Appoints CEO of European Operations

Posted By Terrance Barkan, Monday, October 19, 2020
Battery anode and graphene company Talga Resources is pleased to announce the appointment of Martin Phillips as the Chief Executive Officer of its European operations.

The appointment of Mr Phillips as CEO Europe follows Talga’s significant progress in building an ultra-low emission anode supply chain in Europe for greener lithium-ion batteries. Talga’s vertically integrated Vittangi Anode Project is steadily moving towards construction with 19,000tpa of anode capacity planned to start in 2023 and further expansion options currently being scoped.

As CEO Europe, Mr Phillips will focus on delivering on Talga’s technical and commercial initiatives underway in Europe including partner development with Mitsui and other parties, as well as Talga’s growing list of local European and global battery customer engagements.

Prior to joining Talga as Chief Operating Officer in 2016, Mr Phillips was the former Commercial Manager of Iluka Resources Ltd, responsible for implementation of business growth and development strategies and M&A. His previous positions included engineering and management roles in battery recycling programs and smelting innovations at MIM’s Mt Isa and UK operations.

In addition to his role as CEO Europe Mr Phillips will continue to oversee Talga’s operations as the Company’s COO. Mr Phillips will remain based in Europe, dividing his time between the UK and Sweden, and reporting to the Talga Board.

Talga Managing Director Mark Thompson commented: “Our maturing stage of development means this is the right time to further strengthen our European leadership. Martin’s experience, having been the COO of Talga for several years and previous Commercial Manager of international mineral sands producer Iluka Resources, will be invaluable in bringing Talga’s Vittangi Anode Project into production. This is a pivotal time for the Company and we are fortunate to have Martin leading our European operations going forward.”

Talga Non-Executive Chairman Terry Stinson commented: “Martin is an excellent choice for the role and his appointment as CEO Europe will strengthen local executive leadership to better support our strategic goals and objectives. Martin will continue to work in conjunction with Talga Managing Director Mark Thompson to deliver on our goal of becoming Europe’s largest producer of ultra-low emission natural graphite anode for lithium-ion batteries.”

Tags:  Battery  Graphene  Li-ion Batteries  Mark Thompson  Martin Phillips  Talga Resources  Terry Stinson 

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Ten Things about Graphene Electronics

Posted By Terrance Barkan, Monday, October 19, 2020
Simon Thomas CEO of Paragraf, outlines ten facts about graphene, its role in the electronics industry, and potential future applications everyone should be aware of.

1. Researchers used sticky tape to create the first graphene

When the first graphene available for research was produced back in 2004, it was created using the ‘Scotch tape method’ – an exfoliation process involving the use of sticky tape to pull carbon layers from the top of a graphite block. Since then, several alternative methods have been developed. One option is to grind or pulverise a block of carbon to create graphene nanoparticles. Another way to achieve graphene is liquid phase epitaxy (LPE), which involves evaporating or pulverising liquids that contain carbon to form platelets or films on surfaces. Sublimination, on the other hand, involves thermally reducing carbon-containing solids, so only carbon is left on top of the solid. Finally, some manufacturers opt for chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PE-CVD), which focus on reacting carbon-containing gases at high temperatures.

2. Unrivalled benefits make graphene a wonder material

Graphene is frequently referred to as the wonder material, with good reason. It is over 100 times stronger than steel while being extremely light, over 100 times more conductive than silicon and features the lowest resistivity of all known materials at room temperature. When you combine this with optical transparency of over 97 percent, very high flexibility, the highest thermal conductivity of any material, and thermal and chemical stability, the potential is staggering. Graphene is the first single material that can offer all these benefits. These characteristics mean that graphene can help enhance many existing technologies in the electronics sphere as well as across other industries and help overcome challenges that have hindered the development of new technologies.

3. Graphene could be the revolution the electronics industry is waiting for

Graphene is ideally suited for electronics applications, thanks to its high thermal and electrically conductive properties, as well as its lightweight nature, being only one atom thick. The electrons in graphene have much higher mobility, and hence speed under an applied electric field, than semiconductors, such as silicon, that are widely used in electronic devices. Therefore, using graphene makes it possible to create more efficient devices that operate faster than conventional alternatives while using less power. Even though graphene is lightweight and flexible, it is significantly stronger mechanically than standard semiconductors, enabling it to tolerate much higher voltages. This is likely to become increasingly vital as all sectors of society look to embrace a greater degree of electrification. Additionally, when operating at these higher powers, graphene’s thermal stability and ability to conduct heat away rapidly reduce device complexity and materials costs. Ultimately, this unique combination of characteristics can help enable entirely new applications in the electronics industry.

4. Different types of graphene enable different technologies

There are three main groups of graphene products and technologies. Small particulate, or platelet, graphene is often supplied in a liquid and referred to as graphene suspension. Graphene flakes, typically around 5mm or smaller in size, are usually free-standing and easy to handle with simple tools. Finally, large-area graphene consists of layers of graphene supported on a substrate material, which can be up to 8 inches in size. Each type of graphene can be used for a wide range of applications. For example, simple exfoliated flakes have for long been used in research and development to demonstrate in lab-scale applications what graphene can do as an electronic material. They have also been used to make transistors that could potentially lead to electronic products that operate much faster, with lower power consumptions and weigh far less than existing electronics. The material can also lead to much more sensitive sensors, which could be game changing in applications such as medical diagnostics. Even in small particulates, graphene offers exceptional wear resistance and strength, making it highly useful as an additive in materials, solutions, and composites. Graphene paints, for example, have been shown to reduce water friction on ships’ hulls, making operation more efficient. Alternatively, they have also been used to further enhance the high strength properties of carbon composite materials used in aircraft wings. Large scale graphene, on the on the other hand, is crucial for enabling the scaling-up and commercialisation of graphene products, particularly electronics.

5. Paragraf’s proprietary graphene technology is fundamentally different

Paragraf has developed and perfected, a process for depositing single-atom-thick materials, such as graphene, that offers several unique benefits. Chief amongst them is the ease of use: Paragraf’s method results in graphene being produced on top of standard substrates, such as silicon, sapphire, and semiconductors, making it compatible with today’s manufacturing techniques, equipment, and infrastructure. It is also silicon technology compatible, in contrast with many existing graphene forms, which have high levels of contamination arising from the manufacturing technique used. Therefore, graphene can be directly plugged into the electronics device manufacturing chain, enabling it to be used like current standard materials. Crucially, unlike many other manufacturers, Paragraf fabricates graphene using a process called MOCVD (Metalorganic Chemical Vapor Deposition). This is key to overcoming the challenges associated with graphene created by conventional CVD (Chemical Vapor Deposition), such as purity and reproduction issues. Thanks to this innovative approach, for the first time, graphene is now available in forms and formats that will allow the scaling of single device lab prototypes to large scale, volume manufacturing. These technological advances indicate that graphene has real potential to enhance or even directly replace standard materials in many electronic devices, unlocking new levels of end technology performance.

6. Graphene brings unprecedented accuracy to magnetic sensing

As graphene’s sheet carrier concentration – the number of electrons per unit area able to move through the material carrying charge – is very low, the material can be up to 50 times more sensitive than a standard semiconductor, such as silicon. This is a significant advantage when configuring the material to interact with other electrical or magnetic fields, for example, in a Hall Sensor. Furthermore, graphene is very robust and doesn’t suffer from the thermal impacts that affect conventional semiconductor devices, which allows the sensor to work in extremely high and low temperatures, including the ultra-low cryogenic range.

7. Graphene drastically reduces the Planar Hall Effect

As a two-dimensional material, graphene doesn’t exhibit the same directional properties as thicker or bulk materials, such as silicon. This is particularly important when it comes to Hall Effect sensors, as it helps mitigate an undesired feature called the Planar Hall Effect. Typically, three-dimensional materials are more prone to the Planar Hall Effect where out of plane fields can interfere with the measurements from the desired sensing plane causing spurious results. The single-atom thick structure of graphene (i.e. the lack of a third dimension) helps eliminate these errors and achieve higher precision mapping of magnetic fields. That’s why graphene sensors can offer far superior performance compared to traditional Hall Sensors. They can also be used in applications that traditional technologies have not been able to address, for example in extremes of radiation and temperature.

8. Paragraf pioneered the graphene-based Hall Effect sensor

For its first commercial application, Paragraf wanted to create a product that would demonstrate the power of graphene and highlight the advantages it offers when used as an electronic sensor. The company targeted a ubiquitous sensor to demonstrate the performance enhancement graphene can bring to a well-known electronic device and hence present a test case for graphene’s real-life potential. Paragraf’s hypothesis was that the performance of these legacy devices could be significantly improved with sophisticated graphene technologies. The resulting performance improvements could benefit many applications where accuracy is vital, including medical diagnostics, vehicle drive train efficiency, and global positioning.

9. Paragraf’s graphene technology is being tested by CERN

CERN (the European Organization for Nuclear Research) uses high precision and reliable measurement performance for many ongoing projects. That’s why the Magnetic Measurement section of the organisation is continuously looking for new ways to optimise the accuracy of its measurement technologies. Paragraf’s Hall Effect sensor was of particular interest to CERN scientists as, unlike other Hall Effect sensors, it displays negligible Planar Hall Effect, minimising inaccuracies in measurement and delivering much-improved measurement accuracy. This mutual interest in the development of magnetic sensing has led Paragraf and CERN to embark on a partnership to test the Hall Sensor’s capabilities and demonstrate the unique properties graphene opens for magnetic measurements.

10. The future spells more cost-effective manufacturing and improved performance

Future applications for graphene are very wide ranging. One of the most exciting areas of application is large-area graphene, which is the key to turning R&D projects into real-world products. With the availability of large-area graphene layers, many different fields of technology are set to benefit, including computing, energy generation, and energy storage. For example, in solar power applications, constraints arising from traditional construction methods currently mean that the solar cells have maximised efficiency at approximately 23-24 percent. However, by supplementing the silicon-based cells with graphene, this performance could be increased by up to three percent – a very significant increase. Paragraf is also currently looking at many other areas where graphene can prove transformative, including as a replacement for indium tin oxide (ITO). ITO is presently widely used in many fields of optoelectronics, as a transparent electrically conductive electrode. It is vital for many applications, but the associated cost and scarce availability of indium present challenges to manufacturers. Here, graphene could prove a good alternative. Its unique qualities could enable it to replace ITO in applications including solar panels, mobile phones, television screens, computers, and organic LEDs.

Tags:  CERN  chemical vapor deposition  CVD  Electronics  Graphene  LED  Paragraf  Semiconductors  Sensors  Simon Thomas 

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Automating 2-D Material Exfoliation with Suji Park

Posted By Terrance Barkan, Monday, October 19, 2020

Suji Park is a scientific associate in the Electronic Nanomaterials Group at the Center for Functional Nanomaterials (CFN), a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven National Laboratory. Since joining the CFN in October 2019, she has been designing and building hardware for the automated exfoliation of high-quality atomically thin “flakes” from 3-D bulk materials. When these 2-D material flakes are stacked into layered structures, new electrical, optical, magnetic, and other properties can emerge.

Such 2-D heterostructures could find applications in areas including catalysis, solar energy, and quantum computing. Park received a bachelor’s degree and PhD in materials science and engineering from Pohang University of Science and Technology in South Korea. She then went on to do three postdocs—one at a neutron imaging facility at the Korea Atomic Energy Research Institute, another in Stanford’s Chemical Engineering Department, and a third at the Stanford Institute for Materials and Energy Sciences at SLAC National Accelerator Laboratory.

What characterizes 2-D materials, and why are scientists interested in them?
2-D materials are ultrathin. They are just a few atoms thick—or even just a single atom thick! The most well-known 2-D material is graphene, which is made of sheets of carbon exfoliated from graphite. The different layers of graphite are held together by weak forces, making them easy to detach. This is why we can make 2-D single-layer flakes of graphene. By stacking flakes from different materials, we can create layered structures that are essentially new materials. This lets us tune their mechanical, optical, and electrical properties. There are exciting theoretical predictions for making quantum devices based on 2-D materials, but the bottleneck is actually making these layered materials.

Why is flake fabrication so challenging?
The traditional way to make 2-D materials is through mechanical exfoliation. Adhesives are repeatedly attached to and detached from a bulk crystal so that the fragments get thinner and thinner. When the materials become thin enough, the adhesives are pressed into silicon wafers to transfer the flakes onto the wafer surface. Eventually, you end up with some very small-sized monolayers.

However, the mechanics of this exfoliation process are not very well understood. This process is laborious, has very low reproducibility, and the quality of the flakes strongly depends on who is performing the exfoliation. Because of the lack of understanding, controlling the size, shape, and other parameters of the flakes is quite difficult. People spend a lot of time to get just one perfect flake. Then, they have to repeat this process many times to build complex layered structures.

Graphene was discovered in 2004. Why is our understanding of exfoliation mechanics still limited after all these years?
This has been a question of mine, too. When I began researching mechanical exfoliation, I found that many scientists have simulated how mechanical exfoliation works. However, these results are limited in terms of their applicability to real-world material performance.

Systematic experiments, in which all variables are carefully controlled, are difficult to perform because exfoliation has multiple steps. For example, if I have three possible variables—pressure, temperature, and speed—and I want to find out how speed affects the exfoliation process, I would fix the temperature and pressure and test the process for selected speeds. But for manual exfoliation, it’s not really possible to fix, or even to measure, the peeling speed. You can’t really ask a scientist to peel at a precise speed. This is a limitation of relying on human hands to make materials. Moreover, we lack statistical methods to analyze exfoliated flakes, which are difficult to see and characterize from images.

From an engineering standpoint, reproducibility and reliability are very important. Automation can help by minimizing human engagement. These factors are the motivation behind the automated 2-D material sample preparation system that I’m building to generate consistent, high-quality flakes.

What is involved in building this automated system?
When I joined the CFN, a prototype exfoliator already existed as part of the first generation of a larger automated machine called the QPress, or Quantum Material Press. This exfoliator used a stamp made of a polymer (PDMS) instead of a tape to perform basic robotic motions such as pushing and pulling.

First, I wanted to understand the factors important to mechanical exfoliation. By understanding this process, I can start to control it. I began by studying pressure-sensitive adhesives, which are adhesive tapes that stick to surfaces via applied pressure, and the theoretical background of mechanical exfoliation, step by step. I found that there are factors that we can control, such as pressure, temperature, and dwell time (how long the tape is adhered on a surface). But what is the appropriate amount of pressure? How long do we need to apply that pressure? What kind of pressure application is better—pushing or rolling? Answering such questions is the first step of automation.

To start, I upgraded the QPress exfoliator with functions to quantitatively control the temperature and pressure with various adhesives. With this setup, I could fulfill basic tests for each of these parameters and find specifications required for automation. I also tested the idea of using a roller instead of a stamp to apply pressure, temperature, and rolling speed at the same time. I tried a commercial laminator, and it actually worked! This test opened a new direction for us to consider for the automation process.

More recently, I came up with a new design for a fully automated roll-to-roll (R2R) exfoliator, relying on the knowledge I gained from my early experiments. On the basis of this design, I built a semi-automated R2R exfoliator. With this setup, I can do systematic research to better understand the underlying mechanisms of mechanical exfoliation and find optimized conditions.

As I explained, mechanical exfoliation is simply a combination of two steps: attachment and detachment, or peeling, of adhesives. With the early push-and-pull type of exfoliator, I could focus on the first step. However, the second step is as critical as the first. Using the R2R exfoliator, I want to control and compare important parameters in the detachment process besides temperature, pressure, and rolling speed (or dwell time). One parameter is the peeling speed and angle. For example, if you peel the tape at 45 instead of 90 degrees, the peeling force changes.

How does the R2R exfoliator work?
The R2R exfoliator has several components. A motorized tape unwinder continuously supplies bare pressure-sensitive adhesive tape from a reel. The tape runs over a roller for source material deposition, picking up the source materials. The tape with the source particles is located under a press roller. A sample stage moves to the left, and the roller compresses the source materials at a pressure similar to that of manual exfoliation. After the materials are compressed, we bake the sample using a heating plate installed in the sample stage. Finally, we move the sample stage to the right. The combined motion of a tape rewinder and the sample stage causes the compressed tape to peel off the sample surface. We can control the peeling speed with the sample stage and the peeling angle with an angle adjustment roller.

What excites you most about studying a process that is still not well understood?
Through my research, I am building an entirely new facility with unique capabilities. I am starting from a very basic understanding, progressing step by step. My role is to integrate the incremental findings and complete a big puzzle in my own creative way. It is challenging, but small improvements in understanding fundamental steps in 2-D materials fabrication will allow us to move forward and eventually complete the whole system. This system will help other researchers save time, effort, and research funds and support the creation of new 2-D materials that could be used in our daily lives. Contributing to society in this way makes me feel very good.

Which materials are you using for the tape and which 2-D materials are you exfoliating? Are the 2-D materials limited to those of interest for quantum information science, as the QPress name suggests?
For the purpose of machine development, I am currently using a simple commercial tape, the same that you would use in any office setting. Using commercial tapes is nice because we can easily test different kinds of adhesives. For instance, I am also studying wafer dicing tapes that are used in the semiconductor industry because they leave less residue on the wafer surface after exfoliation.

For 2-D material exfoliation, my current target is graphene because it is the most widely studied. The project team is also trying to produce high-quality flakes from materials for which it is hard to obtain such high quality—for example, very brittle materials. Team member Young-Jae Shin is an expert in 2-D materials. With the commercial laminator, he has been testing molybdenum disulfide and tungsten disulfide, which are more brittle than graphene. I will test these materials with the R2R exfoliator after I finish testing graphene.

Our goal is to help users exfoliate any materials that interest them. The QPress project was initially started with quantum materials in mind, given the recent emphasis on quantum information science research. However, the machine will be available to users who are looking to generate any kind of 2-D materials. Because the machine can run 24 hours a day, it saves a lot of time in generating flakes. Also, we’re planning to make a library-type database of different flakes that users can access for their research.  

You mentioned that the exfoliator will be part of a larger automated machine, the QPress. Are you only working on the exfoliation component?
The final QPress will have robot arms that transfer samples from the exfoliator station to cataloger, stacker, and characterization stations. This workflow will be automated. While my main focus so far has been on making the exfoliator, I’m also working on designing an automated setup for the stacker and figuring out how to combine these different modules. Achieving full automation could be difficult because different tools have different requirements in terms of sample environments, required motions, and physical space. It’s a complicated design issue.

My goals by the end of this year are to complete the fully automated R2R exfoliator, make the R2R exfoliator a functional part of the QPress, and build the first prototype of the automated stacker.

It sounds like building the exfoliator and integrating it into a multicomponent system requires a combination of 2-D materials knowledge and mechanical design expertise. How are you applying your knowledge and experience to this project?
My PhD was in materials science and engineering. For my thesis, I used a synchrotron x-ray microscope to study wetting on polymers. During my postdoc at Stanford, I continued using the synchrotron x-ray microscope to study the fluid dynamics of tear films on soft contact lenses.

When I went to SLAC, I changed my career path. I started studying microstructural changes in solid crystals through ultrafast electron diffraction. I was slightly involved in 2-D material studies, mostly on the experimental side rather than data analysis. Because I was a joint postdoc at Stanford and SLAC, my role was split between maintenance and user support of the electron diffraction facility and my own research. I was frequently involved in the development of new functions at the facility. For example, I designed an upgraded version of a vacuum chamber and manipulator system. So, over the years, I have become used to diving into new areas. As a result, I’m more open-minded and less fearful of taking on new and challenging projects.

Though my field of expertise is not 2-D materials, my unique background in materials science, fluid mechanics, and soft-matter physics and my hands-on experience is very useful in terms of building a facility for 2-D material exfoliation. For example, the adhesives used in mechanical exfoliation are polymers. What I researched during my PhD is the wetting property of polymers, or how they contact liquid surfaces. The exfoliation process is related to wetting but for solid flakes instead of liquids. So, I can apply my expertise related to the mechanics to understand interface phenomena between adhesives and flakes.

What led you to pursue studies in materials science and engineering and a career in scientific research?
I have liked science and math my entire life. Initially, I wanted to be a high school math teacher. But I realized that being a scientist was more aligned with my goal of making a general impact on the world. I chose materials science because materials are the fundamental elements accelerating technology development. I’m very excited to see what 2-D materials emerge from the QPress and how they are applied to new technologies.

Tags:  2D materials  Brookhaven National Laboratory  Energy  Graphene  quantum computing  Suji Park  U.S. Department of Energy 

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First Graphene makes progress with novel supercapacitor materials

Posted By Terrance Barkan, Monday, October 19, 2020
First Graphene have completed initial testing of their novel supercapacitor materials in collaboration with WMG a world leading battery test laboratory. Initial results show that the materials perform well in supercapacitor cells. Further work is underway to improve cell performance.

Chemical batteries, such as those based on Li ion technology, store large amounts of energy which can be discharged over many hours or miles. The energy is released by a chemical reaction which occurs between the anode and cathode. After many cycles the chemistry needs to be replenished and the battery replaced.

Supercapacitors, based on electrical double layer capacitance (EDLC), offer rapid charging and discharging giving a high-power density. These supercapacitors usually use activated carbon as a high surface-area charge storage medium. They do not depend on a chemical reaction as they work on charge separation within the device. This means that EDLC supercapacitors are stable and can typically withstand many charge / discharge cycles.

For electric vehicles (EVs), an ideal energy storage device combines a chemical battery (high energy density and hence long range) with a supercapacitor (rapid charge and discharge) to effectively manage periods where high power is needed for relatively short times, such as when starting and stopping. This will extend the battery life and ultimately extend the range of the vehicle[1].

An ideal route to this combined system is through the use of pseudocapacitor technology, where charge storage occurs through the electrical double layer capacitance mechanism and very rapid redox reactions between the ions in the electrolyte and the active materials on the electrode surface. Pseudocapacitance can increase the performance of a supercapacitor by an order of magnitude.

At the University of Manchester, a novel route to manufacturing materials that are suitable for pseudocapacitors has been identified. The manufacturing process has been progressed by First Graphene Ltd, who have successfully taken the concept from the laboratory scale to an operational environment in a very short time, representing a scale up from a Technology Readiness Level (TRL) of 3 (experimental proof of concept) to TRL6 (technology demonstrated in relevant environment).

The ideal pseudocapacitor material is a hybrid, consisting of an electrochemically active metal oxide such as manganese (IV) oxide supported on a porous, electrically conductive scaffold such as graphene. This combines the benefits of the high theoretical specific capacitance, wide potential range and high electrochemical activity of manganese (IV) oxide with the good electrical conductivity and versatility of graphene.[2]

First Graphene Ltd have successfully demonstrated that this material can be manufactured at scale via a proprietary electrochemical process. Figure 1 shows high surface area manganese oxide “rosettes” grown onto the surface of a PureGRAPH® platelet. The process is extremely flexible and can be used for deposition of any single or mixed transition metal oxides. This opens up other applications, such as electrocatalysts for water-splitting cells used in the production of hydrogen gas.

[1] Applications of Supercapacitors in Electric and Hybrid Vehicles – Research Report UCD-ITS-RR-15-09

[2] Wu D, Xie X, Zhang Y, Zhang D, Du W, Zhang X and Wang B (2020) MnO2/Carbon Composites for Supercapacitor: Synthesis and Electrochemical Performance. Front. Mater. 7:2. doi: 10.3389/fmats.2020.00002

Unlike competitor materials, that are often simple mixtures, these materials are unique – having a nano-scale active metal oxide grown directly and intimately onto a conductive carbon scaffold. The company recognizes that this unique material requires a novel cell design to optimize performance and continues work with the University of Manchester on the materials chemistry and with Warwick Manufacturing Group at the University of Warwick with regard to processing the materials into test cells and evaluating the electrochemical performance.

In initial studies, a cell architecture has been devised using the novel metal oxide decorated graphene and standard ancillary materials – binder, separator and electrolyte. The cells have been shown to perform well as supercapacitors easily matching the performance of industry leading activated carbons. Of particular note is the capacitance per unit area of the metal oxide decorated graphene which at 1.0 Farad/m2 is significantly higher than activated carbon at 0.02 Farad/m2.  This indicates the manganese dioxide sample exhibits pseudocapacitive behavior and is not solely reliant on double layer capacitance.

Working closely with the WMG and the University of Manchester, the Company has identified further improvements that will be required in the assembly of supercapacitor cells for these novel materials. The next phase of development will focus upon optimization of electrolyte and cell lifetime improvements.

Craig McGuckin, Managing Director of First Graphene Ltd. says “We have made good progress in developing these unique materials by scaling manufacture and demonstrating high surface capacitance. Further work is required. We look forward to developing an optimized cell with our research partners.”

Mark Copley, Associate Professor of WMG says “The metal oxide decorated graphenes are an exciting class of materials for use in supercapacitors. I look forward to continued collaboration with First Graphene to help them realize their energy storage application ambitions”.

Tags:  Batteries  Craig McGuckin  electric vehicles  energy storage  First Graphene  Graphene  Mark Copley  supercapacitor  University of Manchester  University of Warwick 

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Q&A with ME Professor Xinwei Wang on New NSF grant to manufacture novel graphene aerogel-based photon sensors

Posted By Terrance Barkan, Friday, October 16, 2020
Explain to us what you are examining for this recent NSF grant you received.

This project is to design and manufacture micro-size bolometers that are based on graphene aerogel (GP). GP is a very light material, whose density can be much less than that of air. GP has a very low thermal conductivity, is flexible, and is electrically conductive. In fact, it is a very unique material quite different from traditional aerogels that are hard and non-electrically conductive (for many of them). We will develop a new laser-assisted chemical reduction manufacturing technique to directly manufacture microsize level GP circuits for bolometers. This new laser-assisted technique opens a very novel way in advanced manufacturing that is beyond heating/melting/solidification in current laser-assisted manufacturing.

The abstract mentions that this project has both military and civilian applications. Can you name a couple examples for each of these areas?

Bolometers using the micro-size sensors manufactured in our project will feature super sensitivity (0.05 K), very broad spectrum light detection (<0.4 um to over 20 um), and very fast response (~1 ms). Also they will have very high spatial resolution, and are expected to find broad applications as night surveillance cameras, infrared high solution and sensitivity temperature sensors for industry and research use, and thermographic camera to sense infrared radiation.

Considering Iowa State University’s role as a land-grant institution, will this project have any applications to industries that are especially relevant here in Iowa?

Our technique development could see broad applications in Iowa, such as farm-field high sensitivity and resolution temperature monitoring, remote human body temperature sensing for health condition checking, and wind turbine blade structure health diagnosis.

The K-12 outreach is an interesting component to this project. Why was this included as part of the project? What exactly do you plan to do for this?

This is a great question. In fact, during our lab tour to high school students, we have demonstrated the temperature sensing capability of our material to students, and they are very interested. In this project, each year we will hire one undergraduate student to do paid summer research, and will also high one high-school teacher to support one-month summer intern in our lab to significantly extend the impact of the project on education.

What are some of the mechanical engineering concepts and methods that apply to this research?

The project itself indeed requires multi-disciplinary knowledge, including material synthesis, structure characterization, and thermophysical design and testing. Our lab’s research has gone far beyond the traditional mechanical engineering scope. But the thermophysical design and testing (mechanical engineering research) will play a critical role in the project. Also we will hire students of materials science and applied physics areas to work on the project.

Does this project build upon past work you’ve done?

Yes, this project was built on our past extensive work on graphene aerogel, including synthesis, thermophysical properties studies, structure characterization, and structure domain and interface study using our thermal reffusivity theory. These place us at a very good starting point to conduct the project.

Are there any other individuals or agencies that should be acknowledged here?

This project has no co-PIs, and will be solely conducted at ISU. But I do really appreciate the preliminary results that are developed by my former Ph.D. student: Yangsu Xie, now a professor at Shenzhen University, China. She has done a great job, and was also awarded the ISU Research Excellence Award during her study here.

When did work on this project begin? For how long will this be funded?

This is a 3-year project starting on August 15, 2020 with a total funding of $349,652

Anything else you want to add?

I am so excited to conduct this project. My laboratory has focused mostly on micro/nanoscale thermal transport: design, characterization and control. This is the first project we are focusing on laser-assisted manufacturing. Also this year I have another project funded by DOE [Department of Energy] to conduct research on manufacturing. Our strong technical expertise in theory, micro/nanoscale physics characterization and control will find us unique positions in manufacturing and will enable us to make novel contributions and advances.

Tags:  Graphene  graphene aerogel  Iowa State University of Science and Technology  Nick Hunter  Sensors  Xinwei Wang 

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Posted By Terrance Barkan, Friday, October 16, 2020
RMC Advanced Technologies (RMC AT), a subsidiary of NanoXplore headquartered in Montreal, Canada, plans to expand its existing manufacturing facility in Newton. RMC AT recently acquired the Newton facility and operations from Continental Structural Plastics in September. Over the next three years, RMC AT plans to create 49 new jobs and invest a minimum of $7 million in new facility construction, machinery, and equipment. Salaries for the new employees will vary by position and experience. The overall average salary will be higher than the Catawba County average wage.

With nearly 400 global employees, RMC Advanced Technologies is an international manufacturer of graphene-enhanced plastics and composite products for industrial and transportation markets. The newly-acquired Newton operation further positions the company with the ability to continue to produce body and hood components for major North American truck and bus manufacturers. As part of the expansion, RMC AT will be constructing a new paint line, allowing the company to offer existing and new customers a turnkey solution and distinguish their offering from other competitors in the marketplace.

“RMC Advanced Technologies is extremely excited to have acquired and, in quick order, to be expanding our new Newton operation to better fulfill the needs of our North American customers,” said Ali Karnib, Vice President of Operations – Composite Business Unit. “We greatly appreciate the support from the State of North Carolina, Catawba County, and the City of Newton on this expansion project and we look forward to being an involved corporate citizen in our new community.”

"Catawba County is firmly committed to supporting our manufacturers and our manufacturing workforce,” said Randy Isenhower, chair, Catawba County Board of Commissioners. “With the expansion of RMC Advanced Technologies, we continue to strengthen our transportation components cluster and create new opportunities to grow our workforce.” 

“RMC Advanced Technologies considered operations across the globe for this expansion,” said Newton Mayor Eddie Haupt. “We are delighted they felt the City of Newton and Catawba County offered them the best mix of low business costs, access to key customer supply chains and a skilled manufacturing workforce. We appreciate their recognition that Newton provides great opportunities through our talented workforce and outstanding utility service. We look forward to growing with RMC Advanced Technologies for many years to come.”

“As we have been working with RMC Advanced Technologies on their expansion, we have been highly encouraged by the company’s desire to be actively involved in our community,” said Dr. Garrett Hinshaw, chair of Catawba County EDC. “Our community needs partners like RMC Advanced Technologies if we are to build impactful and lasting efforts like K-64 and Catawba Valley Community College’s Workforce Solutions Complex.”

RMC Advanced Technology plans to hire a variety of employees for the new manufacturing operation in areas of production, maintenance, quality, management, and supply chain logistics. Hiring is expected to begin early 2021.

Local incentives will be considered for the project at upcoming public hearings by the Catawba County Board of Commissioners and Newton City Council.

Tags:  Ali Karnib  composites  Eddie Haupt  Garrett Hinshaw  Graphene  NanoXplore  plastics  Randy Isenhower  RMC Advanced Technologies 

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ZEN Graphene Solutions Announces New Research Collaboration Agreement on Carbon Aerogels with German Aerospace Center

Posted By Terrance Barkan, Friday, October 16, 2020
ZEN Graphene Solutions today announced that it has signed a new research collaboration agreement with the Deutsches Zentrum für Luft- und Raumfahrt (“DLR”, the German Aerospace Center) to investigate the use of Albany PureTM graphene-based nanomaterials in the fabrication of novel carbon aerogel composites. The goal of this collaborative research project titled, “Development of Innovative Composites based on Carbon Aerogels”, is to develop electrode materials for new generation batteries and will build on the collaboration between ZEN, DLR and Dr. Lukas Bichler at the University of British Columbia‐Okanagan Campus (UBC-O) that was previously reported on October 15, 2018 and November 1, 2019.

In November 2019, ZEN reported on encouraging preliminary results on graphene-carbon erogel battery development work which indicated that relatively low loadings (<5 wt.%) of graphene-based material, combined with DLR’s proprietary carbon aerogel structure, can result in an anode with a significant specific discharge capacity. Preliminary best results were achieved with a 2 wt.% loading of graphene dispersed in aerogel and resulted in an initial specific discharge capacity of 2800 mAh/g and a discharge capacity of 1300 mAh/g after 50 cycles at a current capacity of 186 mA/g. These unoptimized results were believed to be better than those currently reported in the literature for graphene aerogel batteries. Graphene-enhanced aerogels could have the potential to be a low-cost, low-weight, high-performance composite materials for near future energy storage applications.

Additionally, DLR has received federal funding from the Helmholtz Association to create the Helmholtz Innovation Lab, called ZAIT, or the Center for Aerogels in Industry and Technology, which will be working together with industrial partners on the development of aerogels. ZEN supported this application with a letter of intent indicating the Company would continue to collaborate with DLR in developing graphene-based aerogel batteries and other graphene-based products.

Francis Dubé, ZEN CEO commented, “We are pleased to move forward with DLR and UBC-O, and continue our collaboration. Initial results were interesting and this research has us excited about the future potential of this technology.”

Tags:  Batteries  composites  German Aerospace Center  Graphene  Lukas Bichler  nanomaterials  University of British Columbia‐Okanagan  ZEN Graphene Solutions 

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WMG and Senergy Innovations Ltd Launch Graphene Enabled All Polymer Solar Thermal Cell

Posted By Terrance Barkan, Friday, October 16, 2020
Solar thermal cells continue to attract much interest as they have massive potential to heat water in a cost-effective and sustainable process. To date, the efficiency of these cells has been limited as the polymers used in their manufacture are poor thermal conductors.

However, thanks to funding from BEIS (Department for Business, Energy & Industrial Strategy) a team of researchers led by Professor Tony McNally, from WMG, at the University of Warwick in partnership with Senergy Innovations Ltd have developed the first nanomaterial enabled all polymer solar thermal cell.

The thermal properties of the polymers employed are modified such that heat from sunlight can be transferred with high efficiency to heat water in a cheap and sustainable manner. The modular design of the cells allows for the rapid construction of a solar thermal cell array on both domestic and industry roofing.

The team are now working with a consortium of industry partners focused on manufacturing the solar thermal cells in high volumes.

Dr Greg Gibbons, at WMG, and his team have also produced the first prototype (1:1 scale) of the solar thermal cell fully manufactured by 3D printing. This activity has been transformative in guiding the design and critical aspects of the manufacture of the solar thermal cells.

Professor Tony McNally, Director of the International Institute for Nanocomposite Manufacturing (IINM), at WMG, University of Warwick comments:

“It is really pleasing to see several years of research activity and the understanding gained being translated in to a real world application. Our fundamental work on the thermal conductivity of 1D and 2D materials, including graphene, and composites of these materials with polymers could revolutionise the supply of affordable, clean and sustainable energy.”

Christine Boyle, CEO, Senergy Innovations Ltd. adds:

“Switching to advanced polymer materials meant a more efficient manufacturing process and more flexible product design. This resulted in the breakthrough of the low cost, low carbon, lightweight smart Senergy panels. Our job now is to ensure that Senergy solar panels become a key part of the smarter built environment and make renewable heating and cooling systems affordable and accessible for everyone.”

Tags:  BEIS UK  Christine Boyle  Graphene  Greg Gibbons  International Institute for Nanocomposite Manufact  Senergy Innovations  Solar Cells  Tony McNally  University of Warwick 

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Why the hype about graphene?

Posted By Terrance Barkan, Thursday, October 15, 2020

Graphene is one of the most innovative materials to be developed and utilised this century. Researchers at Swinburne have been heavily involved in its development, innovation and commercialisation.  

What is graphene?
Graphene is both the lightest and strongest material known to man.  It is a single layer of carbon atoms arranged in a honeycomb-like structure and is the most electrically conductive substance on Earth.

It was discovered in 2004 by an unusual technique. Researchers from the University of Manchester in the UK used sticky tape to peel flakes from a lump of graphite, separating the layers until they were just one atom thick.

Graphene has proven highly versatile and has been used for building materials, military equipment, solar cells and smart devices.

Swinburne’s graphene ‘hub’
As part of the Graphene Supply Chain Cooperative Research Centre Projects (CRC-P), Swinburne is working with industry partner Imagine Intelligent Materials to develop graphene to meet strict quality assurances and to be used in large-scale manufacturing. It is also working to establish industry partnerships.

The material is also a key focus of the Next Generation Materials program, led by Professor Baohua Jia at Swinburne’s Manufacturing Future Research Institute (MFRI).

Deputy Vice-Chancellor (Research and Enterprise), Professor Bronwyn Fox, says Swinburne researchers are working to establish standard knowledge and procedures for investors and suppliers of graphene.

“In the supply chain certification lab, we are developing the research to understand the relationship between the structure and performance of graphene so that industry can have security of supply, ensure successful applications and strengthen future investments in the technologies that utilise this material.”

Swinburne researchers have analysed the complete graphene supply chain – from production to industry practice. They have investigated graphene’s properties and tested its ability to combine with other materials in engineering developments, as well its potential to be used as a thin, protective coating. 

A graphene-enabled future
Astronomer and Lead Scientist of the Royal Institution of Australia, Professor Alan Duffy recently spoke with Victoria's Lead Scientist, Dr Amanda Caples about the future of graphene, its many uses and why it's a key part of Industry 4.0.

Tags:  Alan Duffy  Amanda Caples  Baohua Jia  Bronwyn Fox  Graphene  Royal Institution of Australia  Swinburne University of Technology  University of Manchester  Victoria State Government 

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