Filters

2014 - 20202

More filters

20202
Reset filters

Settings

Author: Eckert, J. × Start date: 2020 × Start date: 2014 × Publisher: Basel : MDPI AG × WGL Institute: IFWD ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Preparation and cycling performance of iron or iron oxide containing amorphous Al-Li alloys as electrodes
    (Basel : MDPI AG, 2014) Thoss, F.; Giebeler, L.; Weißer, K.; Feller, J.; Eckert, J.
    Crystalline phase transitions cause volume changes, which entails a fast destroying of the electrode. Non-crystalline states may avoid this circumstance. Herein we present structural and electrochemical investigations of pre-lithiated, amorphous Al39Li43Fe13Si5-powders, to be used as electrode material for Li-ion batteries. Powders of master alloys with the compositions Al39Li43Fe13Si5 and Al39Li43Fe13Si5 + 5 mass-% FeO were prepared via ball milling and achieved amorphous/nanocrystalline states after 56 and 21.6 h, respectively. In contrast to their Li-free amorphous pendant Al78Fe13Si9, both powders showed specific capacities of about 400 and 700 Ah/kgAl, respectively, after the third cycle.
  • Thumbnail Image
    Item
    Fabrication of metastable crystalline nanocomposites by flash annealing of Cu47.5Zr47.5Al5 metallic glass using joule heating
    (Basel : MDPI AG, 2020) Okulov, I.; Soldatov, I.; Kaban, I.; Sarac, B.; Spieckermann, F.; Eckert, J.
    Flash Joule-heating was applied to the Cu47.5Zr47.5Al5 metallic glass for designing fully crystalline metastable nanocomposites consisting of the metastable B2 CuZr and low-temperature equilibrium Cu10Zr7 phases. The onset of crystallization was in situ controlled by monitoring resistivity changes in the samples. The effect of heating rate and annealing time on the volume fraction of the crystalline phases and mechanical properties of the nanocomposites was studied in detail. Particularly, an increase of the heating rate and a decrease of the annealing time lead to a lower number of equilibrium Cu10Zr7 precipitates and an increase of tensile ductility. Tailoring of these non-equilibrium microstructures and mechanical properties may not be possible unless one starts with a fully glassy material that opens new perspectives for designing metastable nanomaterials with unique physical properties.