With its research, the Fraunhofer Institute for Solar Energy Systems ISE makes a significant contribution to a sustainable, economical, secure, and socially just energy supply on a global scale. As one of the world‘s largest solar research institutes, our goal is to drive forward the energy transition, by providing viable technological solutions, which are generated through excellent research results, successful industry collaborations and spin-offs. At Fraunhofer ISE around 1,300 employees conduct research in four key areas: energy provision, energy distribution, energy storage, and energy use.
In the market-oriented business areas of Photovoltaics: Materials, Cells and Modules, Photovoltaics: Production Technology and Transfer, Solar Power Plants and Integrated Photovoltaics, Electrical Energy Storage, Power Electronics and Grids, Climate-Neutral Heat and Buildings, Hydrogen Technologies as well as System Integration, the Institute develops materials, components, systems and processes. In addition, we perform analyses, carry out studies and provide consultations.
At our Center for Electrical Energy Storage, we are researching the next generation of lithium-ion batteries as well as promising alternatives such as zinc-ion or sodium-ion technologies. We are looking at the entire value chain - from materials and cells to battery system technology and a wide range of storage applications. In our laboratory infrastructure in Freiburg's "Haidhaus", we offer extensive scientific tests and inspections at cell and system level, as well as state-of-the-art characterization processes.
The work focuses on the mechanical characterization, ageing and safety assessment of battery cells, combining systematic expansion and swelling measurements under constrained and unconstrained conditions with cell-level abuse testing (heating, overcharge and penetration). It investigates the relationship between mechanical deformation, State of Charge (SoC), temperature and ageing, as well as the mechanisms triggering thermal runaway. The activities also include the development and validation of coupled stress–expansion–degradation and thermal runaway models using COMSOL Multiphysics, supported by experimental data, gas analysis and EIS-based monitoring. These models contribute to a better understanding of cell degradation, thermal runaway behavior and battery safety at both cell and module levels.
