Core competence "energy systems"

Sustainable and affordable energy supply and efficient energy management are the focus of current research policy. Within the core competence “energy systems” we work on electrical energy storage devices for mobile and stationary systems, and on fuel cells and electrolysis as well as heat and material energy storage systems and their applications. We have accumulated more than 30 years of electrochemical and chemical know-how, laying the foundations for the development of efficient and cost-effective storage devices and converters.

Mobile 15 kW/ 30 kWh redox-flow battery container solution for an energy-autonomous field camp
© Fraunhofer ICT | Mona Rothweiler
Mobile 15 kW/ 30 kWh redox-flow battery container solution for an energy-autonomous field camp

Electrocatalysts for fuel cells and next-generation electrolyzers are a focus in the area of converters. The main emphasis is on the development of alkaline direct-alcohol fuel cells, for example palladium non-noble metal alloy catalysts for alcohol oxidation or ionomers with high stability in alkaline alcohol solutions. We are developing anode catalysts for mediumtemperature fuel cells that have a high tolerance for impurities (especially sulfurous compounds), for operation with logistic fuels available for military use. We also have a high level of competence in the online analysis of electrochemical processes, which can also be applied to investigate degradation processes in vehicle PEMFCs. A further competence is the design of systems for use in unusual environments, for example under water.

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

Individual test stand with gas analysis for the detection of transient changes in gas composition
© W. Mayrhofer
Individual test stand with gas analysis for the detection of transient changes in gas composition

Networks and alliances

Fraunhofer ICT pools its competence with other institutes of the Fraunhofer-Gesellschaft through Fraunhofer networks and alliances. The spokesperson of the Fraunhofer Battery Alliance, Prof. Dr. Jens Tübke, is an employee of Fraunhofer ICT. Fraunhofer ICT is also active in the alliances "Energy", ”Space“ and ”Building Innovation“ in relation to this topic.

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 include the following focal points:

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

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)

Facilities and equipment

  • Battery charging and discharging stations incl. climatic chambers for characterization of battery cells and modules
  • Argon glove boxes
  • In-operando layer thickness measurements at electrode and cell level during electrochemical tests
  • High-speed and infrared cameras
  • Cryostats and climate chambers from -70 °C to 250 °C
  • Scanning tunneling microscope (STM) / atomic force microscope (AFM) with 3D imaging in the atom/nano range
  • Digital microscopy with magnification factor up to 5000 in two- or three-dimensional image
  • Scanning electron microscope (SEM) / spatially resolved elemental analysis using energy dispersive X-ray spectroscopy (EDS)
  • RAMAN and infrared (IR) spectroscopy
  • Analysis of surface size and porosity using BET gas adsorption
  • Confocal microscope for surface characterization
  • Ion analysis by capillary electrophoresis (CE), free-flow electrophoresis (FFE) and ion chromatography
  • Thermal analysis to record physical transformations and chemical reactions with heat flow DSC
  • Gas analysis using GC, MS, GC/MS and gas FTIR
  • Thermal, mechanical and electrical safety testing facilities for battery cells and modules up to 2 kWh and fuel cell modules
  • Synthesis options for supported electrocatalysts up to gram scale
  • Test systems for electrochemical catalyst characterization and aging tests on membrane electrode assemblies
  • Differential electrochemical mass spectrometry (DEMS) to investigate reaction and corrosion products
  • Medium-temperature cell (120 °C – 200 °C) with online mass spectrometry (HT-DEMS)
  • Equipment for the production of membrane electrode assemblies by inkjet, hot spray and electrospinning
  • Several single cell test benches for the characterization of membrane-electrode units for hydrogen PEMFC, PEM, AEM and HT-PEMC based direct alcohol fuel cells, HT-PEMFCs operated on reformate, PEM electrolysis
  • Test system for time-resolved online mass spectrometric measurements to investigate transient processes in automotive PEMFCs such as corrosion during switching operations or gas exchange of inert gases
  • Test benches for the investigation of short stacks (PEMFC, DAFC and HT-PEMFC) up to 500 W
  • Test benches for stack characterization of PEMFC and HAT-PEMFC stacks up to 5 kW with hydrogen, surrogate reformate for operating pressures up to 5 bar and with pure oxygen
  • System development and investigation of components through hardware-in-the-loop method
  • Environmental simulation, especially mechanical tests (vibration, impact, etc.) on fuel cell stacks and systems
  • Online mass spectrometer with membrane flow unit for analysis of the liquid phase
  • Sputtering equipment for coating with metals
  • Various high temperature furnaces with the possibility to simulate H2-, CO-, CO2- or SO2- containing atmospheres up to 800 °C, at pressures up to 50 bar
  • Measuring stand for redox flow battery stacks up to 60 kW
  • Test benches for redox flow battery stacks in a large-scale environment up to 250 kW
  • Testing of materials for VRFBs (cell test, durability test,
    electrolyte tests)