FestPoLiS

Project description

Lithium-sulfur batteries have higher specific energy, more environmentally friendly components, and lower material costs compared to lithium-ion batteries. In addition, the liquid and flammable electrolyte poses a safety risk that plays an important role in transportation applications. Therefore, solid electrolytes represent a promising class of materials, which can increase the safety and improve the energy density. Polymer-based solid electrolytes in particular are an attractive materials science approach that both enhances safety and suppresses the shuttle effect. By introducing functionalized fillers into the polymer matrix, the material parameters can be adjusted very flexibly, in particular the ionic conductivity can be increased and so-called hybrid polymer-based solid electrolytes can be obtained. This class of materials has the potential to be scalably synthesised and easy to process, making it promising for industrial use. For the improvement of the material parameters of the solid electrolyte, a traceable and reliable quantitative analysis is needed for a complete understanding of transport and conversion processes. For this, multidimensional in-operando methods, ex-situ investigations on a broad scale and spectroscopic investigations at the electrode/electrolyte interfaces are very promising approaches to provide important insights into the complex reaction and transport mechanisms. Therefore, the overall goal of this project is to fabricate high-performance Li/S pouch cells (multilayers) with novel hybrid polymer solid electrolyte and a kinetically optimized cathode.

Task and targets of the project:

• Synthesis of hybrid polymer electrolytes with increased conductivity compared to the pure polymer electrolytes.
• Innovative and scalable production concepts for cathodes for Li/S solid-state batteries.
• Implementation of novel and robust operando/ex-situ analytical approaches for a detailed understanding of the dissolution mechanism of polysulfides in polymer-based solid-state batteries and of processes at the interfaces between electrode and solid electrolyte.
• Investigation of the mode of action of modified nanoparticle fillers to increase ionic conductivity (lower operating temperatures).
• Innovative processing of the polymer-based Li/S cathodes and solid electrolytes to monolayer and multilayer pouch cells.
• Characterization of pouch cells according to industry standards.

Contact:

Mahsa Hokmabadi
mahsa.hokmabadi(at)tu-braunschweig.de

Niko Grotkopp
n.grotkopp(at)tu-braunschweig.de

Marvin Nebelsiek
marvin.nebelsiek(at)tu-braunschweig.de