Scientific activities of the Solid State Ionics Division
The main area of scientific activity of the division is physics of superionic conductors and materials exhibiting mixed electronic-ionic conduction. Superionic conductors are solid materials exhibiting high ionic conductivity (values close to liquid ionic conductors).
Our research is highly diversed and concern thermal, structural and electrical properties of materials. Such an approach enforces using many experimental techniques, such as thermal analysis (DSC/DTA/TGA/TMA), X-ray and neutron diffractometry, electron microscopy (SEM, TEM), elemental analysis (EDX), Raman spectroscopy, impedance spectroscopy, thermoelectric and Hall measurements, electrochemical measurements and computer modelling.
Solid State Ionics Division consists of two scientific groups: Amorphous and Crystalline Superionic Conductors Group.
Amorphous Superionic Conductors Group
In this group, mostly amourphous materials, exhibiting mixed conduction are investigated. One of the research goals is improvement of electrical properties by means of thermal nanocrystallization of glasses. To reach this goal, complex (thermal, structural and electrical) investigation is necessary. Then, the nanocrystallization process can be described both quantifically (nucleation and crystallization speed) and qualitatively (crystalline phases, grain sizes). This allows us to correlate the phenomena of conductivity growth with other properties.
Activities:
mixed conduction glasses with composition similar to Li-ion cathode materials (like (V2O5, LiFePO4 olivine, NASICON-like structures - Li3V2(PO4)3 or Li3V2(PO4)2F3 and their sodium analogues.
other cathode materials, obtained in crystalline form based on LiVPO4F tavorite. Innovative synthesis method - microwave processing is used.
optically active glasses - materials containing rare earth metals ions (like Eu) immersed in glassy matrix (e.g. Eu in LiF-TiO2-P2O5 matrix). When stimulated with UV radiation, these glasses exhibit photoluminescence and thus can be used as white light sources and luminophores in LCD screens. Research on how luminescence spectra depends on ions valence state and glass structure is conducted.
glassy composites from materials exhibiting different type of conductivity (e.g. composite of 30AgI·35Ag2O·35P2O5 and 90V2O5·10P2O5 glasses, conducting silver ions and electrons). These glasses exhibit high values of electrical capacity, which make them candidates for supercapacitators.
solid electrolytes for Li-ion batteries - allow to build all-solid batteries, which is important for special uses (like military). Two groups of materials are investigated: LTP (LiTi2(PO4)3) and LATP (Li1.3Ti1.7Al0.3(PO4)3). The research is devoted to enhancement of electric conductivity.
Members of the group: Jerzy Garbarczyk, Prof., Marek Wasiucionek, Prof., Jan Nowiński, Prof., Bogdan Wnętrzewski, Dr., Wioleta Ślubowska, Dr and Tomasz Pietrzak, Dr.
Crystalline Superionic Conductors Group
Crystalline Superionic Conductors Group is devoted to crystalline materials of various purposes - what they all have in common is the idea of electrical properties and crystal structure enhancement by changing the chemical composition. The important part is careful analysis of investigated materials in the wide range of temperatures using diffraction (X-ray and neutron) techniques. Complementary methods (RMC and DFT computer simulations) are also used. Combining those leads to obtaining reliable information on atoms position in primitive cell and their occupancy. Next, this allows to investigate the correlations between crystal structure and electric conductivity.
The group hass well-equipped immpedance spectroscopy laboratory, allowing to conduct electrical measurements in wide range of temperatures and atmospheres. Transference numbers (ratio of electronic/ionic to total conductivity) can be measured, which is necessary to evaluate the possibility of application of given material.
Activities:
oxygen ions conductors based on bismuth oxide - these materials are considered as oxygen detectors and electrolytes in solid oxide fuel cells (SOFCs), allowing the cell to work in lower temperatures than in conventional SOFCs based on YSZ (yttrium stabilized zirconia).
polymer lithium ions conductors - these make an alternative to conventionally used liquid electrolytes. In the group, a so-called "polyelectrolytes" are investigated - they consist of poly(ethylene oxide) with the lithium salt dispersed in (e.g. LiN(CF3SO2)2).
lithium-manganese and lithium-titanium spinels are materials exhibiting mixed conduction and find the application as electrodes in Li-ion batteries. The research is concentrated on improvement of intercalating and electrical properties.
Members of the group: Franciszek Krok, Prof., Władysław Bogusz, Prof., Wojciech Wróbel, Dr. habil., Michał Marzantowicz, Dr. habil., Marcin Małys, Dr., Monika Dynarowska, Dr., Marzena Leszczyńska-Redek, Dr. and Anna Borowska-Centkowska, Dr.
