The focus of the Fiber Optic Sensor Systems department at the Fraunhofer Heinrich Hertz Institute HHI is on application-oriented research and on the development of a new generation of photonic sensors, which are characterized by extreme miniaturization, high network and communication capability and exceptionally low power consumption. By utilizing Bragg grating sensors, an optical monitoring of the state of charge and state of health of individual battery cells is realized, which enables an improved detection of malfunctions as well as a dedicated system analysis. In order to develop battery status sensors target-oriented for realistic application areas, the HHI operates a battery and sensor test center, in which batteries are comprehensively examined in cooperation with research partners on cell, module and system level by electrical, thermal, mechanical and chemical stress tests.

The HHI is focusing on the development and production of fiber optical sensors for cross-influence-free, electrochemically inert and thus non-destructive measurement of mechanical, thermal and chemical states in the interior of cells. For this purpose, the sensor zones are functionalized in such a way that measurements in the active materials and in the electrolyte are possible over the entire life span of a cell. Through the interaction with conventional monitoring systems, degradation processes can be classified and correspondingly separated from each other in terms of signal components, so that a valuable contribution can be provided to the comprehensive and, above all, time-efficient characterization of new types of cell materials.

Project participations

The Fraunhofer Institute for Manufacturing and Advanced Materials IFAM is one of the leading independent research organizations in Europe in the fields of shaping and functional materials and adhesive bonding technology and surfaces. Currently 700 employees in 20 departments focusing theirs scientific know how in seven core competences which are metalic materials, polymers, surface technology, bounding, shaping and functionalisation. Fraunhofer IFAM covers the whole value-creation chain from the development of new materials and product design up to the integration into industrial production – including pilot trials and customized workforce training in new technologies. Since 15 Years Fraunhofer IFAM’s Department for Electrical Energy Storage has been doing research on materials science and manufacturing technology solutions for the next generation of batteries.

The department of Energy storage focuses with its broad and long-lasting experience in material and process development, for manufacturing and design of electrodes and battery cells, particularly for Lithium Ion batteries but also on the next generation batteries like all solid state batteries and metal-air systems, to improve specific storage energy, service life / cycle stability, operational safety and cost-benefit ratio.

Based on the core competences on electrochemistry, powder technology and process technology, the synthesis of new materials, evaluation of alternative process technologies for electrode processing and cell aging mechanisms will be addressed. For this the complete value chain from powder synthese to cell manufacturing and characterization will be available at the institute.

In addition the modelling for aging prediction and quality evaluation with focus on operation strategies for batteries will be addressed. Based on the collection of extensive relevant battery cells data new models for lifetime prediction will be analysed.

Project participations

BeLiMIA