Another promising battery alternative for the future could be solid-state batteries – a technology that is being researched worldwide. It is similar to conventional lithium-ion technology, but differs in that its electrolytes are solid instead of liquid. This results in greater safety and storage capacity, as well as shorter charging times. These performance enhancements could be particularly interesting for electric mobility due to shorter charging times and longer ranges.
Despite extensive research activities, however, no measurable progress has been made so far compared to the established lithium-ion technology. This is a problem that is being addressed by the FestBatt competence cluster. In order to meet the needs of the international market and to make a mass application accessible to Europe as quickly as possible, the cluster combines the expertise of over 180 researchers from 45 groups and 22 research institutions in Germany. The primary goal of the interdisciplinary collaboration funded by the German Federal Ministry of Education and Research (BMBF) is to build expertise in the field of solid-state batteries and to characterize, develop and implement various cell concepts. In the first funding phase, suitable materials were identified and various solid electrolytes synthesized.
The second funding phase is now focusing on the practical development of the acquired fundamentals: complete battery systems and methods for their production are to be developed. The research institutions involved are spread across various platforms in a total of ten collaborative projects. On the one hand, they are further developing the material fundamentals and cell concepts of solid-state batteries. The focus here is on the synthesis, optimization and upscaling of solid electrolytes of certain material classes, as well as the development of suitable concepts for half and full cells in solid-state batteries. On the other hand, process-related aspects and unresolved problems that usually affect several cell concepts are addressed. Specifically, the focus is on optimizing cell properties and evaluating process flows, safety aspects, charging cycles or process technologies. The work steps are complemented by methods for comprehensive characterization of each material class and for analyzing battery operation.
KIT researchers are involved, among other things, in the characterization of contact and boundary surfaces using X-ray, synchrotron, and neutron radiation, but also carry out various microscopy techniques on complex multiphase systems. The aim is to provide all participating partners within the cluster with cathode materials that have special and fully characterized protective layers.
Even though a number of scientific and technological challenges still need to be overcome before solid-state batteries can be mass-produced, progress and transdisciplinary cooperation are already promising. Developments and results are discussed in close consultation with industry, the project management organization and the Federal Ministry of Education and Research. The high level of networking should enable transparent research- and application-oriented knowledge transfer not only among the participating institutions, but also into society.
