News Article | May 3, 2017
One of the biggest challenges when designing an electric car is where to put the batteries. Every vehicle has hundreds to thousands of separate battery cells, each surrounded by a housing and connected to the car systems and sensors. This complex design takes up space - more than 50 percent of the area dedicated to batteries inside the car is taken up with housing and contacts. But now a team of engineers at the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) has developed a new battery concept that could substantially decrease the amount of space needed for housing and contacts - meaning more batteries can fit in the same car. Their system stacks battery cells directly one above the other across a large area, as opposed to the traditional approach where individual cells are strung side-by-side in small sections. The direct connection to each cell in the stack allows current to flow over the entire surface of the battery, significantly reducing electrical resistance. "With our new packaging concept, we hope to increase the range of electric cars in the medium term up to 1000 kilometers," Mareike Wolter, Project Manager at Fraunhofer IKTS. The key to being able to do this is a new electrode - in this case, a metallic tape coated on both sides with ceramic storage materials. One side is the battery's anode - the other is the cathode. Developing each material is a complex process, involving a suspension of powdered ceramics mixed with polymers and electrically conductive materials. "We use our expertise in ceramic technologies to design the electrodes in such a way that they need as little space as possible, save a lot of energy, are easy to manufacture and have a long life," said Wolter. The research is still a work-in-progress right now, but the concept is being scaled up to larger battery cells which can be installed in real electric cars. Initial tests are due for 2020, but Wolter is optimistic that this should take place without difficulties: "One of the core competencies of our institute is to adapt ceramic materials from the laboratory to a pilot scale and to reproduce them reliably," she said.
News Article | May 2, 2017
Production of the bipolar electrode on a pilot scale. Credit: Fraunhofer IKTS You cannot get far today with electric cars. One reason is that the batteries require a lot of space. Fraunhofer scientists are stacking large cells on top of one another. This provides vehicles with more power. Initial tests in the laboratory have been positive. In the medium term, the project partners are striving to achieve a range of 1000 kilometers for electric vehicles. Depending on the model, electric cars are equipped with hundreds to thousands of separate battery cells. Each one is surrounded by a housing, connected to the car via terminals and cables, and monitored by sensors. The housing and contacting take up more than 50 percent of the space. Therefore, the cells cannot be densely packed together as preferred. The complex design steals space. A further problem: Electrical resistances, which reduce the power, are generated at the connections of the small-scale cells. Under the brand name EMBATT, the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden and its partners have transferred the bipolar principle known from fuel cells to the lithium battery. In this approach, individual battery cells are not strung separately side-by-side in small sections; instead, they are stacked directly one above the other across a large area. The entire structure for the housing and the contacting is therefore eliminated. As a result, more batteries fit into the car. Through the direct connection of the cells in the stack, the current flows over the entire surface of the battery. The electrical resistance is thereby considerably reduced. The electrodes of the battery are designed to release and absorb energy very quickly. "With our new packaging concept, we hope to increase the range of electric cars in the medium term up to 1000 kilometers," says Dr. Mareike Wolter, Project Manager at Fraunhofer IKTS. The approach is already working in the laboratory. The partners are ThyssenKrupp System Engineering and IAV Automotive Engineering. The most important component of the battery is the bipolar electrode – a metallic tape that is coated on both sides with ceramic storage materials. As a result, one side becomes the anode, the other the cathode. As the heart of the battery, it stores the energy. "We use our expertise in ceramic technologies to design the electrodes in such a way that they need as little space as possible, save a lot of energy, are easy to manufacture and have a long life," says Wolter. Ceramic materials are used as powders. The scientists mix them with polymers and electrically conductive materials to form a suspension. "This formulation has to be specially developed – adapted for the front and back of the tape, respectively," Wolter explains. The Fraunhofer IKTS applies the suspension to the tape in a roll-to-roll process. "One of the core competencies of our institute is to adapt ceramic materials from the laboratory to a pilot scale and to reproduce them reliably," says Wolter, describing the expertise of the Dresden scientists. The next planned step is the development of larger battery cells and their installation in electric cars. The partners are aiming for initial tests in vehicles by 2020. Explore further: Freezing lithium batteries may make them safer and bendable
News Article | May 3, 2017
One of the big stumbling blocks preventing the wide scale acceptance of electric cars is dreaded range anxiety. With an average range of around 100 mi (161 km) per charge, all-electric vehicles still can't compete with more conventional cars – especially if lights, windscreen wipers, or air con are needed. To level the playing field a bit, Fraunhofer is working on a new battery design that could increase an electric car's range to 1,000 km (621 mi). Electric cars don't have a single battery, but a collection of battery packs made of hundreds or thousands of individual battery cells that are packed in and wired together. These separate battery cells each require a housing as well as terminals, wiring, cables, and electronic monitors, which all combine to take up 50 percent of the space of a whole battery pack. Additionally, all those electrical connections sap away current through resistance. In partnership with ThyssenKrupp System Engineering and IAV Automotive Engineering, the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden is developing EMBATT, a new type of battery that reduces the number of those components in a much simpler design that would free up space that could be used to provide extra electricity storage capacity. EMBATT takes its cue from another electrical power source, the fuel cell. Fuel cells work by combining oxygen with a gas, like hydrogen or methane, across a permeable membrane, to generate electricity. One key component of such cells is what is called a bipolar plate. This plate covers both sides of the cell and has a number of functions, but its main purpose is to act as the electrodes to collect the electricity produced by the cell with one plate acting as the anode and the other as the cathode. Fraunhofer's idea is to replace the housings and individual connectors in the battery packs with similar plates. Instead of setting the battery cells next to each other, they would be stacked directly one on top of one other over a large area and covered by plates, which would carry the current across its surface. This would not only simplify the design, but greatly reduce resistance, making more electricity available more quickly. In the Fraunhofer design, this bipolar plate is in the form of a metallic tape that's coated on both sides with a powdered ceramic mixed with polymers and electrically conductive materials. The ceramic acts as an energy storage medium, with one side of the tape acting as the anode and the other as the cathode depending on the formulation of the coating. Fraunhofer says that this arrangement would allow for easy manufacturing and long service life. The upshot of all this is that electric cars could carry bigger batteries that don't takes up more space or add weight, giving cars a range of 1,000 km (621 mi) in the medium term. So far EMBATT has been confined to the laboratory, but the partners are working on scaling up the technology for installation in test vehicles by 2020.
Zgalat-Lozynskyy O.,IPMS |
Herrmann M.,IKTS |
Ragulya A.,IPMS |
Andrzejczuk M.,WUT |
Polotai A.,MRA Laboratories Inc
Archives of Metallurgy and Materials | Year: 2012
Consolidation of commercially available titanium nitride nanostructured powder as well as nanocomposite powders in the Si 3N 4-TiN and TiN-TiB 2 systems have been performed by Spark Plasma Sintering (SPS) in the temperature range from 1200°C to 1550 °C. The effect of non-linear heating and loading regimes on high melting point nanocomposites consolidation has been investigated.
Zgalat-Lozynskyy O.,Ukrainian Academy of Sciences |
Herrmann M.,IKTS |
Ragulya A.,Ukrainian Academy of Sciences
Journal of the European Ceramic Society | Year: 2011
Consolidation of commercially available nanostructured titanium carbonitride (TiCN) powder has been performed by Spark Plasma Sintering (SPS) in the temperature range from 1300 to 1600°C. The effect of non-linear heating and loading regimes on consolidation of high melting point nanocomposites has been investigated. SPS consolidated TiCN material has demonstrated near fully dense and fine homogeneous microstructure with average grains size about 150nm. Nanohardness and fracture toughness of the TiCN nanocomposite have been measured as 33±0.9GPa and 3.2MPam1/2 respectively. © 2010 Elsevier Ltd.
Rose M.,IKTS |
Niinisto J.,CNT |
Niinisto J.,University of Helsinki |
Endler I.,IKTS |
And 3 more authors.
ACS Applied Materials and Interfaces | Year: 2010
The mechanisms of technologically important atomic layer deposition (ALD) processes, trimethylaluminium (TMA)/ozone and tetrakis(ethylmethylamino)hafnium (TEMAH)/ozone, for the growth of Al2O3 and HfO2 thin films are studied in situ by a quadrupole mass spectrometer coupled with a 300 mm ALD reactor. In addition to released CH4 and CO2 water was detected as one of the reaction byproduct in the TMA/O3 process. In the TEMAH/O3 process, the surface after the ozone pulse consisted of chemisorpted active oxygen and -OH groups, leading to the release of H2 CO2 and HNEtMe during the metal precursor pulse. © 2010 American Chemical Society.
News Article | December 1, 2015
Floating homes are becoming increasingly popular in Germany – not only as holiday homes, but also as permanent residences. The Lusatian Lake District (Lausitzer Seenland) is particularly suitable for such a lifestyle: with its 23 lakes and a surface area of over 32 000 acres, it is the largest artificial lake district in Europe. Over decades, the region, which is located between the German states Saxony and Brandenburg, had been characterized by open-cast lignite coal mining. In the coming years, this way of life of living on water will help enhance the region's attractiveness and boost its economy. This is also the objective of the Lusatian autartec project, which the two Fraunhofer Institutes based in Dresden, the Fraunhofer Institute for Transportation and Infrastructure Systems (IVI) and the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), are involved in, as well as other partners from the region such as medium-size companies, manufacturers, the Technical University of Dresden (TUD) and the Technical University of Brandenburg (BTU). They will all work hand in hand to build a floating home on Lake Geierswalde, to the northwest of the city of Hoyerswerda, by 2017. This floating home will not only look elegant, it will also be able to provide for its own water, electricity and heat. "These kinds of energy self-sufficient floating homes do not exist yet," says autartec project coordinator Professor Matthias Klingner of IVI. Many lakes in the Lusatian Lake District are cut off from infrastructure such as water and energy supply. "We want to find a solution for this kind of environment," says Klingner. Standing on a 13 by 13 meter steel pontoon, the house extends over two levels and offers 75 square meters of living space on the ground floor, and another 34 square meters on the first floor. A 15 square meter terrace overlooks the entire lake. The house combines modern architecture and structural engineering with state-of-the-art equipment and building facilities. For example, solar cells are integrated in the building envelope and lithium polymer batteries store the collected energy. In order to save space, the battey systems developed at IVI are integrated into the textile concrete walls or into the stair elements. Researchers at IVI are also working on the efficient provision of heating and cooling systems. A salt hydrate fireplace provides heat on cold winter days: above the fireplace there is a tub filled with water and salt hydrates. "When the fireplace is on, the salt hydrates liquefy and begin to absorb heat," Dr. Burkhard Fassauer of IKTS explains. When the salt hydrates are completely liquefied, the thermal energy can be stored almost indefinitely. In order to release the heat when required, radio-based technology is used to induce crystallization. The principle is known from pocket warmers: to induce crystallization, a metal disc inside is clicked so that the pocket warmer solidifies and gives off heat. When heated in water, the crystals liquefy and the heat is stored until the next click. However, a fireplace is not enough to heat the house during the winter. This is where a zeolith thermal storage unit in the pontoon can help: the zeolith minerals are dried during the summer – a purely physical process in which heat is stored. "In winter, the moist air is enough for the storage unit to give off heat," Fassauer explains. An adiabatic cooling system provides for cool air in the summer. Unlike conventional air conditioning systems, it does not require electricity but uses the principle of evaporative humidification to cool. A surface on the side of the house is landscaped and moistened and the process of evaporation then cools the building envelope. The experts at IKTS are responsible for the water supply in the houseboat. "We are currently developing and experimenting with a closed loop system for drinking and service water," Fassauer explains. To accomplish this, the scientists rely on a combination of ceramic membranes and various electrochemical and photocatalytic processes. Ashore, wastewater is usually treated using biological processes. This is not possible in a floating house. "We must rely on physical and chemical methods. Thus, ceramics provide very efficient ways to bring together processes like photocatalysis, electrochemistry and filtration in a confined space," says Fassauer. Other materials such as steel and plastic would fail in such aggressive processes. The equipment for the circulatory system will be accommodated in the pontoon. Explore further: University of Stuttgart gets a research house for solar heat storage
News Article | April 7, 2016
Researchers have developed a particularly flexible additive manufacturing method that allows them to produce bone implants, dentures, surgical tools or microreactors in almost any conceivable design. At the Medtec medical technology tradeshow in Stuttgart, Fraunhofer scientists will show their research results. The small pharmaceutical plant next to the patient’s bed is no bigger than a two-euro coin. With wires and channels that are just a few hundred micrometers wide, it constantly mixes various drugs — painkillers, blood thinners and antibiotics — and fine-tunes them to the patient’s current health condition. A futuristic scene of modern microreaction technology that doesn’t yet exist in hospitals. The Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden is working to change that in the near future. The researchers are focusing on suspension-based additive manufacturing methods and combinations of them with other manufacturing techniques to create not only microreactors, but also bone implants, dentures and surgical tools. At Medtec in Stuttgart from April 12 to 14, they will be presenting a technological solution for creating medical components in almost every conceivable design using additive manufacturing methods. “We have no limitations in terms of type or color of material for the target components. This allows us to process ceramics, glass, plastic or even metal using thermoplastic 3D printing. One more advantage is that several different materials can be produced at the same time,” says Dr. Tassilo Moritz from Fraunhofer IKTS’s “Materials and Processes” business division. In the lab, the scientists have already successfully made components out of high-performance ceramics and hard metals. Now, they are looking for partners to put their technology to real-world use. One area in which the multi-material approach is important is surgery: endoscopes frequently employ an instrument to first cut open tissue, and then quickly close the blood vessels back up again using electric current. To prevent electricity from shocking the patient, the instrument needs not only high-grade steel, but also insulated ceramic components. “Ceramic substances are often well-suited for medical devices and components. Ceramics are sturdy and can be cleaned thoroughly,” explains Moritz. Researchers arrived at their additive manufacturing method as a result of their expertise in ceramic materials and process technologies. The key to their technology lies in preparing optimum ceramic or metallic suspensions. The mixtures rely on a thermoplastic binder that becomes liquid at temperatures of around 80°C. This is a crucial point in additive manufacturing: it means the suspensions can quickly cool down, and one layer after another can be deposited in sequence. In this binder, they disperse powder particles of metal, glass or ceramics. “Our mixtures are very homogenous, and we precisely set the optimum level of viscosity. Only then can the printer put out the droplet size suitable for the particular component contour. Our mixtures can’t be too liquid or thick. To achieve this, we have to master the preparation technique,” says Moritz. The electrically generated temperature in the printer melts the suspension. After deposition, the droplets immediately harden as a result of the quick cooling process. The workpiece is then built up point by point on a flat platform. This allows different materials to be deposited at the same time via multiple application units. “Another challenge is adjusting the behavior of the different suspensions during the subsequent sintering of the components, to prevent any defects,” says Moritz. “To this end, we modify the initial powder through special grinding processes.” In sintering, finely grained ceramic or metallic substances are heated under pressure. The temperatures of the substances remain so low that the structure of the workpiece does not change. Moritz is hoping for great things from these new options for microreaction technology based on ceramic components. Until now, production technology has prevented a breakthrough in miniature chemical plants. Their use had previously been limited to research labs in the main. That could change: “We can now build ceramic components that fit the application instead of the production process,” says the materials scientist. “To date, ceramic microreactors have mostly been milled out of plates. Internal and external sealing have always been a technological challenge for this. And there has been the problem of making connections that fit. Now, we can just print them onto the ceramic component during manufacturing in whatever form.” This benefits not only doctors, but also pharmacists and chemists. In most cases, they are processing very expensive or hazardous substances. “It is more affordable and safer to first work with minimal quantities in a microreactor,” says Moritz.
News Article | October 10, 2016
Fraunhofer IKTS reports that it has successfully 3D printed a range of hardmetal tools. The tools will be on show at WorldPM 2016 in Hamburg in October. High mechanical and chemical as well as a high temperature resistance and extreme hardness are required for tools that are used in mechanical and automotive engineering or in the construction and forming industry. The researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden say that the tools produced with additive manufacturing (AM) have a ‘quality that is in no way inferior to conventionally produced high-performance tools’. Currently, cutting, drilling, pressing and stamping tools made of hardmetals are generally manufactured using uniaxial or cold isostatic dry pressing, extrusion and injection molding as well as by green shaping. In traditional tool manufacturing, complex geometries, such as helical or meandering cooling channels inside the component, are still implemented at high cost or not possible at all. Now IKTS scientists have succeeded in producing complex hardmetal tools via a binder jetting method. The starting powders or granules are locally wetted with an organic binder by a print head and bound. The challenge was to get 100% dense components, which have a perfect microstructure and thus good mechanical properties. By varying the metallic binder, bending strength, fracture toughness and hardness can be adjusted individually – the lower the amount of binder in the hardmetals, the harder the tool material. The prototypes manufactured at Fraunhofer IKTS have a binder content of 12 and 17% by weight and show a structure comparable to conventional routes. ‘Through the use of 3D printed complex green bodies which were subsequently sintered under conventional sintering conditions, we achieved components with a typical hardmetal structure and 100% density. Moreover, it is possible to get a homogeneous cobalt distribution, thus achieving a comparable quality to conventionally produced high-performance cemented carbide-based tools,’ said Johannes Pötschke, group leader at Fraunhofer IKTS. This story is reprinted from material from Fraunhofer, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
News Article | October 23, 2015
The Jena research team and its innovative battery (from left to right): Prof. Dr. Ulrich S. Schubert, Tobias Janoschka und Dr. Martin Hager. Credit: Anne Guenther/FSU Sun and wind are important sources of renewable energy, but they suffer from natural fluctuations: In stormy weather or bright sunshine electricity produced exceeds demand, whereas clouds or a lull in the wind inevitably cause a power shortage. For continuity in electricity supply and stable power grids, energy storage devices will become essential. So-called redox-flow batteries are the most promising technology to solve this problem. However, they still have one crucial disadvantage: They require expensive materials and aggressive acids. A team of researchers at the Friedrich Schiller University Jena (FSU Jena), in the Center for Energy and Environmental Chemistry (CEEC Jena) and the JenaBatteries GmbH (a spin-off of the University Jena), made a decisive step towards a redox-flow battery which is simple to handle, safe and economical at the same time: They developed a system on the basis of organic polymers and a harmless saline solution. "What's new and innovative about our battery is that it can be produced at much less cost, while nearly reaching the capacity of traditional metal and acid containing systems," Dr. Martin Hager says. The scientists present their battery technology in the current edition of the renowned scientific journal Nature. In contrast to conventional batteries, the electrodes of a redox-flow battery are not made of solid materials (e.g., metals or metal salts) but they come in a dissolved form: The electrolyte solutions are stored in two tanks, which form the positive and negative terminal of the battery. With the help of pumps the polymer solutions are transferred to an electrochemical cell, in which the polymers are electrochemically reduced or oxidized, thereby charging or discharging the battery. To prevent the electrolytes from intermixing, the cell is divided into two compartments by a membrane. "In these systems the amount of energy stored as well as the power rating can be individually adjusted. Moreover, hardly any self-discharge occurs," Martin Hager explains. Traditional redox-flow systems mostly use the heavy metal vanadium, dissolved in sulphuric acid as electrolyte. "This is not only extremely expensive, but the solution is highly corrosive, so that a specific membrane has to be used and the life-span of the battery is limited," Hager points out. In the redox-flow battery of the Jena scientists, on the other hand, novel synthetic materials are used: In their core structure they resemble Plexiglas and Styrofoam (polystyrene), but functional groups have been added enabling the material to accept or donate electrons. No aggressive acids are necessary anymore; the polymers rather 'swim' in an aqueous solution. "Thus we are able to use a simple and low-cost cellulose membrane and avoid poisonous and expensive materials", Tobias Janoschka, first author of the new study, explains. "This polymer-based redox-flow battery is ideally suited as energy storage for large wind farms and photovoltaic power stations," Prof. Dr. Ulrich S. Schubert says. He is chair for Organic and Macromolecular Chemistry at the FSU Jena and director of the CEEC Jena, a unique energy research center run in collaboration with the Fraunhofer Institute for Ceramic Technologies and Systems Hermsdorf/Dresden (IKTS). In first tests the redox-flow battery from Jena could withstand up to 10.000 charging cycles without losing a crucial amount of capacity. The energy density of the system presented in the study is ten watt-hours per liter. Yet, the scientists are already working on larger, more efficient systems. In addition to the fundamental research at the University, the chemists develop their system, within the framework of the start-up company JenaBatteries GmbH, towards marketable products. Explore further: Agreement will lead to commercialization of redox flow batteries More information: Tobias Janoschka et al. An aqueous, polymer-based redox-flow battery using non-corrosive, safe, and low-cost materials, Nature (2015). DOI: 10.1038/nature15746