Materials development and synthesis for solid-state batteries

The realization of solid-state battery production still faces major challenges. The focus is on researching the manufacture of the necessary materials, their properties, and their further processing into battery cells.

At Fraunhofer ZESS, materials for use in future lithium solid-state batteries are synthesized and optimized. All classes of solid-state electrolytes are considered – oxides, sulfides, and polymers. In addition, coatings for cathode materials such as lithium nickel cobalt manganese oxide (NCM) are being developed to ensure compatibility between the active material and the solid electrolyte in a composite cathode.

Sulfides

In the synthesis of sulfide materials, mechanochemical processes using grinding processes and wet chemical synthesis routes are being considered. The evaluation of synthesis parameters for optimizing energy and material requirements and the design of aggregates for scaling the processes to a pilot scale are the main focus in order to be able to provide sufficient material for paste development.

Polymers

Polymer-based electrolytes are being developed both as a protective layer for lithium metal anodes and as polymer separators in solid-state batteries. In addition to evaluating thermoplastic polymers, synthesis parameters for reactive polymers are also being considered. The experimental laboratory work is supplemented by computer simulations in order to make predictions about the properties of polymers using atomistic simulations and to be able to produce promising polymers in a targeted manner.

Oxides

The development of oxides focuses on the refinement of active materials, e.g., lithium-nickel-cobalt-manganese oxide, by coating them with thin, ion-conducting protective layers of lithium metal oxides such as LiNbO3 in order to increase the compatibility between the active material and the solid-state electrolyte. Various material combinations are being investigated and suitable coating processes and parameters are being determined.