FOR 1277:  Mobility of Lithium Ions in Solids (molife)

• Subject Area: Chemistry
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 119336273

The precise investigation of the elementary diffusion processes of ions in solids is, in the case of lithium-ion conductors, currently of enormous worldwide importance for both basic physical and chemical research and for applied materials research. The Research Unit is dedicated to basic studies of atomic dynamic and kinetic processes in lithium-containing solids, i.e. model compounds with partly application-oriented character. The Research Unit includes seven projects with different but complementary focusses, ranging from dimensionality and isotope effects in Li diffusion via the influence of structural disorder and nanostructure to the investigation of extremely slow ionic motion.
For that purpose an extensive range of methods, being unique in its combination, is used, which covers, for example, mass tracer methods, impedance and conductivity spectroscopies, numerous nuclear magnetic resonance (NMR) methods and neutron reflectometry. By use of the complementary microscopic and macroscopic measurement techniques atomic motional processes are investigated on very large time and length scales so that Li jump rates with values from the sub-Hz to the GHz range can be measured. Theoretical studies, which include, in particular, Monte Carlo simulations accompany the experimentally based projects. Model substances and materials include 1D and 2D ion conductors, nanostructured materials (nanotubes and wires), glasses, strongly disordered oxides etc. Leitmotifs of the Research Unit are: (1) Which diffusion paths the elementary Li+ jumps in solids do follow? (2) How the diffusion parameters are affected when the dimensionality of the host matrix is changed? (3) What is the influence of structural disorder of a solid on the Li+ transport process? (4) Can non-classical isotope effects, as in the case of H+, be (quantitatively) detected? (5) How the kinetics of the insertion of Li into the host material can be followed in detail?

• DFG Programme: Research Units
• International Connection: Austria

Projects

• Diffusion pathways and activation energies in crystalline lithium ion conductors (Applicants Bredow, Thomas ;  Lerch, Martin )
• Effect of pressure on transport properties of granular lithium ion conductors (Applicants Behrens, Harald ;  Lerch, Martin )
• Isotopic Effects, Jump Correlation and Diffusion Paths in Li-containing Oxide Glasses (Applicant Welsch, Anna-Maria )
• Kinetics of Li intercalation and de-intercalation in tantalum chalcogenide single crystals (Applicants Behrens, Harald ;  Binnewies, Michael ;  Horn, Ingo ;  Schmidt, Harald )
• Koordination der Forschungsgruppe 1277 (Applicant Heitjans, Paul )
• Li-Diffusion in oxide nanotubes and in ordered nanostructured as well as mesostructured layered materials (Applicants Hanzu, Ilie ;  Wark, Michael ;  Wilkening, Martin )
• Low-dimensional lithium ion conductors (Applicants Heitjans, Paul ;  Lerch, Martin ;  Wilkening, Martin )
• Ultraslow Li Transport on the Nanometer Scale (Applicants Heitjans, Paul ;  Schmidt, Harald )

• Spokesperson: Professor Dr. Paul Heitjans