Core competence "energy and drive systems"

We develop new, efficient options for electrical energy storage, and investigate systems that are already available on the market. Our emphasis is on lithium-ion batteries, all-solid-state batteries, redox-flow batteries and so-called post-lithium-ion systems, such as lithium-sulfur or sodium-based batteries. Cells and battery modules are characterized and simulated thermally and electrically, to tailor them for specific applications. Other topics of interest are safety and abuse investigations with accompanying gas analysis, post-mortem investigations on cells and battery modules, and the development and validation of safety concepts for operation, transport and storage. In our abuse test laboratories we can conduct thermal, mechanical and electrical safety tests on Li-ion cells and on modules with an energy content of up to 2 kWh. In the field of redox-flow batteries we are investigating various cost-effective and sustainable storage materials, and are working to reduce the cost of the overall system, in particular the stack structure and materials.

Our work in the field of converters is divided into three main topics: material development, testing and system development. As regards material development, we focus on catalyst systems for water electrolysis. We address materials for oxygen evolution / (OER) catalysts for PEM electrolysis but also supported catalysts and noble metal-free OER catalysts for AEM electrolysis starting from MOF precursors. We are also developing electrocatalysts for use in HT-PEMFCs and DMFCs. In fuel cell testing, our focus is on method development for the investigation of degradation processes, in particular carbon and ionomer corrosion, using online mass spectrometry. In addition, we support the development of test methods for fuel cell components, for example the characterization of bipolar plates and the GDL. We optimize the operation of commercial fuel cell stacks for special applications in the military and civil sectors and develop the systems required for this, including the selection of suitable peripheral components and the control system.

Hydrogen is used, among other things, as a fuel to power fuel cells in mobile and stationary applications. We ensure the necessary safety, examine the hydrogen in the respective system and investigate various operating conditions - right up to the worst-case scenario. For example, we calculate possible leaks and faults, use theoretical results to direct hydrogen specifically into cavities, and test the implementation at our test site, which is designed for up to three kilograms of TNT equivalent. In addition, we deal with issues relating to the safety distance in the refueling area and the pressure protection of fuel tanks.

For energy supply in residential quarters with regeneratively produced hydrogen, we design the overall layout of the system including the fuel cells for reconversion, the use of the waste heat from the fuel cells, and demand-oriented distribution via local heating networks. We set up the system control and perform stress tests by simulating possible failure cases.

One way to use electric energy efficiently is to generate chemical products. We are working on the development of electrochemical reactors, including electrocatalysts and electrodes, their integration into a complete process, and subsequent process steps. A current example is the electrochemical extraction of hydrogen peroxide by the partial reduction of atmospheric oxygen, combined with its use in a selective oxidation.

Thermal storage devices based on phase-change materials (PCMs) or zeolites are developed and characterized. This involves basic physical and chemical characterization, including the modeling and characterization of adsorption and desorption phenomena using thermoanalytical methods. The design, construction and testing of sorption storage and sorption cooling systems, heat reservoirs based on phase-change materials, and hybrid components combining thermal mass and insulation, are strongly market-oriented and complement our fundamental research activities. In the field of chemical storage, Fraunhofer ICT is concerned with hydrogen as an energetic material and platform chemical. A particular area of expertise is safety assessment and the design of systems, pilot plants and processes.

Important research areas are the handling and especially the storage and transport of hydrogen, the development and performance of specific safety tests and the evaluation, concept and design of hydrogen storage systems. The equipment available at our Application Center for Stationary Energy Storage Devices enables the characterization and development of a wide spectrum of materials, through to the behavior of a storage device in an electric grid with renewable energy sources.

Services and technology transfer

We offer our customers a wide range of development services for electrical and thermal storage devices and electric converters, aimed at different applications in the civil and military sectors. The design and development of fuel cell systems for stationary applications and for vehicles includes:

• complete characterization of PEMFC, HT-PEMFC and DMFC fuel cell stacks
• environmental simulation tests on stacks and systems, e.g. climate tests, effects of shock etc.
• development of operating strategies
• optimization of the interaction between the fuel cell and the battery
• safety analyses
  

We also develop electrocatalysts suitable for use with various fuels (hydrogen, alcohols) in acidic or alkaline fuel cells. We have various test cells and self-developed measuring cells for the evaluation of battery materials such as electrodes, separators, electrolytes and charge eliminators.

• conductivity measurements (electrolyte, membrane, separator)
• evaluation of electrodes (e.g. NCA, NCM, graphite, Si, LCO, LTO, O₂-cathodes etc.)
• tests on separators, and investigation of electrolytes (organic, inorganic, ionic liquid, solid ion conductive) to determine performance and stability
• thermal simulation and cooling concepts for cells, modules and batteries, and development of module and battery concepts with specific cells
• research on next-generation systems (e.g. Li-S, air cathodes, Na-systems, solid ion conductors)

Our mobility is in transition: increasingly, battery electric and hybrid vehicles are entering the market. Until this process is complete, however, combustion engines are still in demand, especially in combination with synthetic fuels. We cover the entire spectrum of drive systems for the mobility transition.

Electric powertrain concepts

In the field of electromotive powertrain concepts, we research and develop electric engines and drive systems for battery electric vehicles. We focus on technologies with a high weight-specific power density and high efficiency. In the field of traction battery system development, our research focuses on safe, lightweight solutions with integrated functions, which meet future demands for high energy and power densities and safety requirements during fast charging and discharging.

Combustion engine powertrain concepts

Our R&D activities address technical solutions for increasing the efficiency of the entire powertrain (mobile and stationary applications) and consequently also for the cross-sectoral reduction of pollutant and greenhouse gas emissions. The internal combustion engine is researched and developed both as a sole propulsion unit and in combination with an electric motor as a hybrid powertrain system. The overriding objective is to minimize fuel consumption and primary energy demand as well as emissions from the powertrain (wellto-wheel). At the same time, the powertrain systems should be designed to be safe, flexible, easily available and compatible with affordable mobility.

Design, simulation and testing

With our competence in the field of design we carry out complex projects for industrial and research partners. For example, we design and manufacture prototypes to validate new operating principles for electric traction components, up to complete internal combustion engines and waste heat recovery expansion devices. To verify and model new design concepts, our research group for simulation analyzes complex components and systems, starting in the concept phase. To assess the behavior of individual components within the system, we use simulation tools for the transfer of heat, material and information. The tool ”IPG-CarMaker“, which simulates the entire vehicle, enables vehicles to be split into different modular components, in order to assess their efficiency during driving. For flow, multi-body and structure simulation we also use professional tools according to current industrial standards. Our research group for testing and validation operates cutting-edge facilities that complement our expertise in the simulation, design, development and manufacture of components and systems in an extensive test field. Complete measurements of multi-cylinder engines (smaller passenger car size) and single-cylinder test engines can be performed on our engine test stand. Our hybrid test stand is used to investigate the entire electrical system within the powertrain. The hot gas test stand is used to investigate waste heat recovery systems, thermoelectric generators, heat exchangers, turbo generators, exhaust-gas turbochargers and exhaust aftertreatment systems.

Batteries, accumulators and fuel cells

Our research and development in the area of batteries and accumulators includes the selection of an energy storage device for specific applications, the electrochemical characterization of materials and cells, identification of the physical parameters of materials for simulations, and causal investigations in the event of cell failure. We work on promising next-generation systems, and conduct safety tests with time-resolved gas analysis on cells and modules. The high efficiency of fuel cells means that they will play an important role in electrical energy generation in the future. Currently, hydrogen, methanol and natural gas are most often used for electricity generation in fuel cells. Developments in this area relate in particular to the optimization of systems in terms of their operating conditions and the components used. Current research emphasizes the integration of fuel cells into mobile and stationary applications, and material development for the systems.

Environmental simulation and product qualification

In special technical units at Fraunhofer ICT, environmental influences on products are simulated and tailored tests are developed. Within the research group for environmental simulation and product qualification, our simulations for the mobility sector include corrosion, pollutant gas, salt spray and splash water, vibration, mechanical shock, pressure, pressure change, climate, temperature and thermal shock. For the electronics sector we simulate dust, water and IP protection class, and in the field of materials research we simulate chemical or UV resistance and aging.