In Situ Investigations of Simultaneous Two-Layer Slot Die Coating of Component-Graded Anodes for Improved High-Energy Li-Ion Batteries

The use of thicker electrodes can contribute to a reduction in cell costs. However, the properties of the electrode must be kept in view to be able to meet the performance requirements. Herein, the possibility of simultaneous multilayer slot die coating is investigated to improve the electrode properties of medium- and high-capacity anodes. The stable coating window of the two-layer slot die coating process is investigated to produce property-graded multilayer electrodes. Electrodes with different styrene–butadiene rubber (SBR) gradients are investigated with regard to adhesive force and electrochemical performance. An increase in the adhesive force of up to 43.5% and an increase in the discharge capacity is observed

Slow Lithium Transport in Metal Oxides on the Nanoscale

This article reports on Li self-diffusion in lithium containing metal oxide compounds. Case studies on LiNbO3, Li3NbO4, LiTaO3, LiAlO2, and LiGaO2 are presented. The focus is on slow diffusion processes on the nanometer scale investigated by macroscopic tracer methods (secondary ion mass spectrometry, neutron reflectometry) and microscopic methods (nuclear magnetic resonance spectroscopy, conductivity spectroscopy) in comparison. Special focus is on the influence of structural disorder on diffusion. © 2017 Walter de Gruyter GmbH, Berlin/Boston

Rheology of membrane-attached minimal actin cortices

The actin cortex is a thin cross-linked network attached to the plasma membrane, which is responsible for the cell's shape during migration, division, and growth. In a reductionist approach, we created a minimal actin cortex (MAC) attached to a lipid membrane to correlate the filamentous actin architecture with its viscoelastic properties. The system is composed of a supported 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer doped with the receptor lipid phosphatidylinositol(4,5)-bisphosphate (PtdIns(4,5)P-2) to which a constitutively active mutant of ezrin, which is a direct membrane-cytoskeleton linker, is bound. The formation of the MAC on the supported lipid bilayer is analyzed as a function of increasing PtdIns(4,5)P-2/ezrin pinning points, revealing an increase in the intersections between actin filaments, that is, the node density of the MAC. Bead tracking microrheology on the membrane-attached actin network provides information about its viscoelastic properties. The results show that ezrin serves as a dynamic cross-linker for the actin cortex attached to the lipid bilayer and that the stiffness of the network is influenced by the pinning point density, relating the plateau storage modulus G(0) to the node density of the MAC

Host Atom Diffusion in Ternary Fe-Cr-Al Alloys

In the Fe-rich corner of the Fe-Cr-Al ternary phase diagram, both interdiffusion experiments [1048 K to 1573 K (775 °C to 1300 °C)] and 58Fe tracer diffusion experiments [873 K to 1123 K (600 °C to 850 °C)] were performed along the Fe50Cr50-Fe50Al50 section. For the evaluation of the interdiffusion data, a theoretical model was used which directly yields the individual self-diffusion coefficients of the three constituents and the shift of the original interface of the diffusion couple through inverse modeling. The driving chemical potential gradients were derived using a phenomenological Gibbs energy function which was based on thoroughly assessed thermodynamic data. From the comparison of the individual self-diffusivities of Fe as obtained from interdiffusion profiles and independent 58Fe tracer diffusivities, the influence of the B2-A2 order–disorder transition becomes obvious, resulting in a slightly higher activation enthalpy for the bcc-B2 phase and a significantly lower activation entropy for this phase