Research highlights from Fraunhofer IKTS

© Fraunhofer IKTS
cerenergy® – Assembling of a ceramic high-temperature battery cell for stationary energy storage.

Electricity from ceramics – environmentally friendly and cost-effective stationary energy storage systems

Stationary energy storage systems are key element of a modern and sustainable energy supply. Globally growing energy supply and the steady increase of peak loads call for reliable solutions. Conventional and renewable power generation will grow together through low-cost energy storage and will provide affordable energy supply in the long-term. Due to latest ceramic processes the high-temperature battery cerenergy® developed at Fraunhofer IKTS has been optimized regarding low costs and good series production.

Batteries based on sodium-nickel-chloride already appeared in the 80s for applications in electric vehicles. Fraunhofer IKTS researchers took up this technology and re-evaluated it in the context of a stationary energy supply that is looking for cost-effective, long-lasting and reliable solutions. Characteristic for batteries of this type is the exclusive use of indigenous raw materials and metals such as nickel, alumina or cooking salt. This makes these batteries ecologically sustainable. Researchers also succeeded in significantly reducing costs. The key to this remarkable development lies in the core of the high-temperature batteries, the ceramic beta-aluminate electrolytes. Their design decisively determines cost and function of the technology. By means of the ceramic manufacturing and synthesizing route available at Fraunhofer IKTS, the processing of both the ceramic powder up to the beta-aluminate is realized. Thus, an all-ceramic large-scale production technology is offered for a contemporary energy storage.

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Photocatalysis module.
© Fraunhofer IVI
autartec® "FreiLichtHaus".

Living on water– self-sufficient waste water treatment by ceramics

A life away from car noise and exhaust fumes – more and more people are attracted to the water. Energy-efficient swimming houses not only fulfill this vitality, but also stimulate the economy of structurally weak regions. In the autartec© project, Fraunhofer IKTS works together with partners from industry and research on a houseboat that supplies itself with water, electricity and heat.

For the water supply in the houseboat, the IKTS researchers develop a closed-loop system for drinking and industrial water. They rely on a combination of ceramic membranes and various electrochemical and photocatalytic processes. While the sewage is always biologically treated onshore, this process is not possible on a floating house. Physical and chemical methods help to solve this problem: ceramics offers very efficient possibilities to bring processes such as photocatalysis, electrochemistry and filtration together in a confined space. Other materials such as steel and plastic would fail in such aggressive operations. The technology for the circulatory system is to be housed in the pontoon that bundles everything under one roof.

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Wire die with integrated cooling channel in the raw state after sintering: at Fraunhofer IKTS in Dresden hardmetal components are developed according to customer requirements via 3D binder jetting.

Design freedom by additive manufacturing – complex hardmetal tools out of the 3D printer

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. To date, reliable cutting, drilling, pressing and stamping tools made of hardmetals are manufactured by uniaxial or cold isostatic dry pressing, extrusion and injection molding as well as by green shaping at Fraunhofer IKTS. 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.

Researchers at Fraunhofer IKTS managed the development of complex hardmetal tools via 3D printing in a quality that is in no way inferior to conventionally produced high-performance tools. The binder jetting method is used in this case. The starting powders or granules are locally wetted with an organic binder by a print head and bound. The challenge was to get one hundred percent 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 twelve and seventeen percent by weight and show a structure comparable to conventional routes.

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3.5-m2 module for field tests with 19-channel NF membranes.
© Fraunhofer IKTS
163-channel NF membranes with membrane surface area/element of 1.3 m2.

Clean recycling water – ceramic nanofiltration membranes for the processing of oil sands

Oil extraction from oil sands requires a large amount of water for different processes. Hot water used to reduce the viscosity of the oil makes up the largest share. After oil/water separation, the water is sent to the tailings ponds and can be reused as “recycle water“ without any further treatment. One approach to increase profitability and sustainability is to make these enormous amounts of water usable for further production processes. Ceramic nanofiltration (NF) membranes can provide a contribution to an economical and environmentally friendly solution.

Due to their resistance to organic matter and oil residues, desalination behavior, and thermal stability, ceramic nanofiltration membranes can contribute to the development of new and more efficient recycling processes, including partial heat recovery. In a current project started in 2013 together with partners Shell Global Solutions International B.V., Shell Canada Ltd., and Andreas Junghans - Anlagenbau und Edelstahlbearbeitung GmbH & Co. KG, 19-channel elements with ceramic NF membranes are being tested in an oil field in Canada. The 19-channel NF membranes showed rejection of alkaline earth metals (Ca and Mg) of up to 80 % and of alkali metals (Na and K) of up to 55 %. The permeate was free of organic matter. Long-term tests performed over several months confirmed the stability of the membranes.

© Fraunhofer IKTS
Manufacturing of Li-ion battery electrodes in the pilot-plant scale – electrode coils.

Electricity from ceramics II – New battery concepts for electric vehicles

Driving enjoyment and electric drive – two terms that are no longer contradictory. Today, hardly any automobile manufacturer goes without an “e-car“ in its range of models. However, further full-scale research in the advancement of energy storage materials and concepts as well as the constant improvement of corresponding production technologies has to be conducted until electric vehicles become established in everyday life. Furthermore, optimal cost, performance and lifespan shall be achieved by means of intelligent system architectures and future-oriented lightweight housings. 

The three project partners thyssenkrupp System Engineering GmbH, IAV GmbH and Fraunhofer IKTS take this a vital step further. With EMBATT, they develop the concept and specially tailored production technologies for lithium-based high-performance batteries set-up in a planar manner, which are directly integrated into the chassis of the vehicle. Thereby, significantly more compact energy storage solutions with energy densities of 450 Wh/l and therefore ranges of up to 1000 km are realizable. This becomes possible by pooling the specific experiences and competencies of the three partners in a joint project. Fraunhofer IKTS conducts research on the development of customized materials and specific methods for electrode manufacturing.

© Fraunhofer IKTS
CeraCode® labeling for metal processing at high temperatures.

Components marking for extreme conditions -– ceramic phosphors in metal processing

For a reliable, clear and tamper-proof marking of semi-finished and end products there are a variety of labeling solutions on the market. These range from a simple serial number to integrated RFID chips (Radio Frequency IDentification). However, these solutions do not meet the specific requirements of metal processing. However, these solutions do not meet the special requirements of metal processing such as high temperatures. Under the name CeraCode® researchers at Fraunhofer IKTS developed a marking for metal components, which defies even high temperatures without affecting the properties of the component.

Core element of the process are ceramic phosphors that respond to optical excitation with a pronounced luminescence. These phosphors are very robust: they withstand high temperatures, are resistant to harsh chemical environment, and can be added to a variety of materials. Thus, it is possible to incorporate the phosphors directly into inks or pastes, and to print on the metal surface. Depending on whether static or dynamic information is required, screen or inkjet printing is used. Both processes can be integrated into production lines. As only a minimal amount of material is printed, an influence on the workpiece characteristics or the adhesion of coatings is excluded. Inks and pastes dosed with phosphors are safe and environmentally friendly, which means no additional health and safety measures are necessary. Due to the high contrast between marking and substrate, automated readout is possible in all lighting situations.