Maike Wirtz

 

Ceramic-Polymer Hybrid Electrolytes for All-Solid-State Lithium-Ion Batteries

Schematic illustration of a lithium-ion battery with LLZ-polymer hybrid electrolyte Copyright: M. Wirtz Schematic illustration of a lithium-ion battery with LLZ-polymer hybrid electrolyte

In recent years the development of efficient battery technologies for the use in portable electronic devices as well as large, stationary, remote energy storage systems became an essential field of research. One important sector is the research on lithium-ion batteries. Currently, conventionally applied lithium-ion batteries contain liquid or gel-polymer electrolytes featuring safety issues such as poor chemical stability, flammability and toxicity. These issues are limited by using solid state hybrid electrolytes.

Among various reported lithium-ion conducting ceramics the cubic polymorph of Li7La3Zr2O12 (LLZ) displays high lithium-ion conductivity and good chemical stability, but requires expensive high temperature treatments. Processing is facilitated by combining polymer and inorganic LLZ powder. Moreover, the thermal and mechanical properties of the polymer are enhanced. From literature poly(ethylene oxide) (PEO) with the conducting salt lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is known to be lithium-ion conducting. In the scope of this thesis hybrid electrolytes combining PEO, LiTFSI and LLZ will be investigated and optimized. Subsequently, this system will be compared to bio-based polymer-LLZ hybrid electrolytes.