The research group Solid Electrolytes is working on the development of nanocrystalline and amorphous solid-state electrolyte materials for lithium-ion batteries, primarily by means of gas-phase (and aerosol) techniques.
It is expected that solid lithium-ion batteries, which consist of a solid electrode and a solid electrolyte that conducts lithium ions, will overcome the safety problems (such as dendrite growth, leakage, and flammability) of the frequently used lithium-ion batteries that contain liquid electrolytes. In addition to improving safety, solid electrolytes offer a wide window of electrochemical stability and high temperature stability. There are already various solid electrolyte materials with the same or higher lithium-ion conductivity than liquid electrolytes, which however are not stable over a wide range of potential. The biggest challenge is to develop material that embodies all of the desired properties.
The two current items of focus in our research group are the synthesis of solid electrolyte nanopowder (crystalline and amorphous) and their further processing to form a nanogranular ceramic solid, and the study of its electrochemical performance. Two of the main synthesis techniques are used: chemical gas-phase synthesis (CVS) and spray pyrolysis (NSP). Both techniques make it possible to synthesize nanocrystalline powder, which in turn permits the study of the potential of nanogranular ceramics in lithium-ion batteries.
The area of research concerned with the manufacture of solid electrolytes as thin layers is expanded as a consequence of using this knowledge of solid ceramics. This is achieved by using the two methods modified CVS and NSP: laser-aided CVD (chemical vapor deposition, chemical gas-phase deposition; LACVD) and spray CVD (NCVD. This research is also supported by the integrated UHV synthesis and characterization system (DAISY-BAT: Darmstadt integrated system for battery research). With the aid of this system, it is possible to develop thin layers of electrode materials and solid electrolytes and to study their surfaces in detail using surface analytics technology at any point during growth.