Quasielastic neutron scattering was used to investigate the low energy transfer dynamics of the complex borohydrides Mg(BH$_4$)$_2$ in the $\alpha$- and $\beta$-modifications, LiBH$_4$ in the low and high temperature crystal structure, and the 1:1 molar mixture of LiBH$_4$+$\alpha$-Mg(BH$_4$)$_2$. All investigated compounds show a rich dynamic behavior below an energy range of $\Delta E = 10$...
The combination of small angle X-ray and neutron scattering (SAXS, SANS) allows a detailed analysis of the mesoscopic structure of colloidal dispersions. It is, however, the atomic and molecular structure of the interface between the nanoparticles and the dispersion medium that governs in many cases the formation, stabilization, and function of the nanoparticles.
In this contribution it will...
The ternary nitrides ZnSnN$_2$ and ZnGeN$_2$ have attracted attention as potential earth-abundant alternatives to III-V solar absorber materials [1]. In the aim to thoroughly understand the effect of oxygen inclusion on the structural features of those materials related to a number of synthesis conditions, we worked on the oxynitride system...
Capacity fade in NMC/C 18650-type cells, cycled 1000 times at a 1C charge/discharge rate, has been characterized by in situ neutron diffraction and electrochemical analysis. Neutron diffraction of the cells show a cyclable lithium loss corresponding to a capacity fade of about 23% in both electrodes of the cycled cell, which is validated by electrochemistry. The cycled cell suffers an anode...
Co-Re based alloys are being developed at the Technische Universität Braunschweig [1], to complement Ni-superalloys in gas turbine engines. Their main advantages are high melting temperature, very high specific strength, good ductility and good oxidation resistance. The Co-Re alloys are strengthened by a fine dispersion of carbides, particularly MC type TaC but unlike gamma-gamma prime based...
High-entropy alloys, equiatomic alloys of five or more principal elements, have recently been the focus of much attention due to their superior structural properties. The stability of these materials is a matter of great concern for application, where it is still not settled whether the prototypical examples are thermodynamically stable phases or just metastable on accessible timescales. In...
In lithium ion batteries the most commonly used anode material is graphite. The lithiation dynamics of graphite anodes is of crucial importance in respect to fast charging or low temperature charging of the cells, as well as aging processes can depend on the intrinsic lithiation properties. Commonly known issues have recently shown that even small effects can cause detrimental lithium plating...
Electrodeposited Prussian Blue Analog (PBA) thin films serve as attractive electrode materials for aqueous Na-ion batteries as grid-scale energy storage systems (ESSs). Such EESs based on secondary batteries are attractive to address the so-called generation versus consumption issue which is inevitably connected to the use of energy from naturally fluctuating renewable sources and the...
Li-ion batteries are playing an important role in powering portable devices, e-mobility applications and off-grid energy storage. Recently we showed that a neutron powder diffraction pattern taken on cylindrical cells like 18650-type can be successfully refined using a contribution from the positive and negative electrodes, current collectors and cell housing. Due to their rollover design the...
Proton conducting oxides are currently receiving considerable attention for their use as electrolytes in solid oxide fuel cells. One of the main challenges for these devices is to combine the advantages of a solid electrolyte with those of operational temperatures below 750 $^\circ$C, which is currently hampered by insufficient conductivities in the targeted T-range. The development of new...
Computational materials design based on first-principle calculations holds a huge potential in identifying novel compounds with superior functional properties. To model thermal conductivity, the progress made with ab initio methods to date allows to calculate wavevector-dependent relaxation rates for every phonon mode in the Brillouin zone. Despite the tempting opportunities offered by...
One promising approach to design bio magnetic field sensors is to combine piezoelectric and magnetostrictive materials in a magnetoelectric composite. Such sensors have the ability to generate an output in response to a magnetic signal from for example the human body. To achieve the extreme sensitivity of less than 100 pT required for medical applications, is a challenge. By using piezotronic...
Enhancing the glass-forming ability of alloys via the minor addition of specific elements is a technique currently at the forefront of BMG design. The addition of only 4 at.% Al or Ti to binary Zr50Cu50 increases its critical casting thickness from 2 mm to at least 5 mm. However, the physical picture of how minor additions improve the glass-forming ability of alloys is still largely...
