TU Braunschweig (Insitute for Particle Technology, Institute of Joining and Welding)
Summary of the overall project:
The main objective of KeraLiS is to combine the advantages of lithium-sulfur batteries and ceramic solid state electrolytes. Sulfur as an active material enables high specific energies and is abundant, but suffers from self-discharge due to the polysulfide shuttle effect. However, the shuttle mechanism can be effectively supressed by the application of ceramic-based solid-state electrolytes. KeraLiS aims to combine two different ceramic electrolytes in a single cell. LLZO will be used at the anode interface, due to its inherent stability against lithium metal, while LATP will be used on the cathode side, because it is cheaper, less dense and less sensitive to exposure with ambient air. The different ceramics will be joined by an innovative laser based approach to reduce parasitic diffusion processes and secondary phase formation. Furthermore, the LLZO as well as the LATP layer will be structured in a laser process to increase the surface area and improve the wetting with lithium metal and sulfur-carbon composites, respectively. The synthesis of the sulfur-carbon composites in a ball mill and by vapour infiltration will be systematically evaluated and tailored in dependence of the catholyte structure.
Objectives and tasks of the iPAT
Systematic evaluation of different synthesis routes for sulfur-carbon composites to enable adaptation of the composite structure to the specific requirements of the catholyte structure.
Establish processes for the infiltration of the sulfur-cabon composites into the catholyte structure.
Characterisation of the catholyte structure, sulfur-carbon composites as well as half and full cells.