CryoFusion meets DLR

What a great day at German Aerospace Center (DLR) in Cologne at the Institute for Frontier Materials on Earth and in Space! I would like to thank Dr.-Ing, Ronja Anton for inviting me and hosting us today.

I had the opportunity to present on the SURFACES group projects, with a deeper dive into my CryoFusion project, which is funded by European Commission. I shared key results and discussed how DCT influences microstructure and residual stresses—and how these changes ultimately impact properties such as corrosion and wear resistance, as well as magnetic and mechanical performance of alloys used in energy sector.

I would also like to thank the team for the insightful tour of the institute, where we had the chance to explore a variety of impressive laboratories.

A special thanks as well for the fruitful discussions on potential future collaborations—looking forward to what lies ahead!

I would also like to thank co-director of Institute for Frontier Materials on Earth and in Space Prof. Guillermo Requena for taking the time to meet with us in person and for seeing our presentations.

Futhermore, I would like to thank also Prof. @Florian Kargl, Dr. Hubertus Thomas, Dr. @Mikhail Pustylnik, @Phillip Eckstein and all the others who hosted us from different departments.

Thank you to everyone for the engaging discussions and valuable feedback!

I would like to thank also Dr.-Ing. Matic Jovičević-Klug and Saro Birgani for presenting their projects and being involved in the discussions. 

#MSCA #MarieCurios #EUHorizon #CryoFusion #SURFACEs #Energy #Fusion

Electrochemically-driven formation of Intermetallic Cu3ZnLi2 alters Li-transport in nanostructured bimetallic battery anode

Check our new article below:

The role of Li-based batteries in the electrification of society cannot be understated, however their operational lifetime is often limited by the formation of dendrites, i.e. the localised deposition of Li that can cause shorts between the two electrodes leading to the failure of the battery. Nanocrystalline bimetallic current collectors can be used for anode-free Li-metal batteries, with improved Li plating and limited or suppressed formation of dendrites. Here, we demonstrate that the microstructure of an α-Brass current collector, Cu 63% Zn 37%, used in an anode-free Li-metal battery evolves during cycling. It initially had a nanocrystalline deformation layer approximately 80 nm in thickness after polishing. After 100 cycles, the initial deformed brass layer was partially converted to a ternary Laves phase Cu₃ZnLi₂ within a nanocrystalline brass matrix that grew to 200 – 250 nm in thickness. Upon Li stripping, the phase partially decomposes electrochemically, but what remains can sequester Li, thus forming “dead Li” thereby contributing to capacity loss. We propose a mechanism for the microstructural evolution including dynamic recrystallization and phase formation. Since this ternary Laves phase emerges during electrochemical cycling alone, binary alloy current collectors must be assessed for metastable ternary phase formation under different cycling conditions to either stabilize and exploit such phases or electrochemically fully strip them.

#Lithium-metal-batteries #Brass current collectors #Laves-phase #Nanocrystalline #Dendrite-suppression #Lithium-ion-batteries

Full article here: https://www.sciencedirect.com/science/article/pii/S0378775326005823

Vacuum dealloyed brass as Li-metal battery current collector: Effect of zinc and porosity

You are welcome to check out our latest article.

“Anode-free” lithium-metal batteries promise significantly higher energy density than conventional graphite-based lithium-ion batteries; however, lithium dendrite growth can lead to internal short circuits with associated safety risks. While porous current collectors can suppress dendrite growth, optimal porosity and composition remain unknown. Here, we show that the temperature during vapor phase dealloying (VPD) of α-brass (Cu₆₃Zn₃₇) controls the surface Zn concentration, decreasing from 8% to below 1% from 500 – 800°C. The surface composition is controlled by the temperature-dependent diffusion. A battery cell maintains > 90% Coulombic efficiency (CE) over 100 cycles when the Zn content is the lowest, whereas the higher-Zn samples degraded to ∼70% CE. The difference in surface composition has hence dramatic effects on battery performance, and our results demonstrate how precise compositional control enables stable Li-metal battery operation, establishing ∼1 at.% surface Zn as optimal for preventing capacity fading and uniform lithium plating, while establishing predictive relationships between processing temperature and surface composition. This work provides design rules for multifunctional current collectors and demonstrates scalable VPD production for next-generation batteries.

Vacuum dealloyed brass as Li-metal battery current collector: Effect of zinc and porosity - ScienceDirect

#Vapor phase dealloying #Current collector #Zinc concentration #Porous collector #Lithium-metal batteries