Silicon-based lithium ion conductors.
Solid electrolytes with superionic conductivity are required as a main component for all-solid-state batteries. We recently discovered fast lithium ion conduction in the novel compound class “lithium phosphide-silicates and -germanates”.
Three-dimensional conducting pathways based on “lithium-rich” phosphidosilicates with ionic conductivity of σ > 10−3 S cm−1 at room temperature and activation energy of 30-32 kJ mol−1 expands the recently introduced family of lithium phosphidotetrelates. Besides the syntheses and structure characterization lithium ion mobility is studied by temperature-dependent impedance and 7Li NMR spectroscopy. Lithium diffusion pathways are analyzed by temperature-dependent powder neutron diffraction measurements in combination with maximum entropy method (MEM) and DFT calculations.
Silicon and germanium as anode materials.
We investigate binary and ternary phase diagrams containing lithium and silicon or germanium. Solutions that contain silicon and germanium atom clusters are used for the preparation of thin film anode materials.