Interesting New Stuff in our Research

Publication: Space Charge Layer Evolution in All-Solid-State Batteries Probed via Operando Kelvin Probe Force Microscopy and Nuclear Reaction Analysis

Chao Zhu, Shigeru Kobayashi, Yuki Sugisawa, Franjo Weber, Kun-Han Lin, Miho Kitamura,
Koji Horiba, Hiroshi Kumigashira, Kazunori Nishio, Ryota Shimizu, Daiichiro Sekiba, Taro Hitosugi,*
and Rüdiger Berger*

The current controversies about the role of space charge layers hinder the development of better solid−solid interfaces and, thus, the improvement of solid-state batteries (ASSBs). To overcome this, we have combined high spatial resolution and nondestructive techniques, operando heterodyne Kelvin probe force microscopy (KPFM), and operando nuclear reaction analysis (NRA) to conduct a study of space charge layers in ASSBs. A model thin-film ASSB was fabricated from lithium (Li)|Li₃PO₄ (LPO)|LiCoO₂ (LCO) for this study. This battery excels due to negligible interfacial defects and side reactions. For a working battery voltage range from 3.0 to 4.3 V vs Li/ Li⁺ , a space charge layer mainly exists at the LPO|LCO interface. This space charge layer arises from the redistribution of Li-ions at the interface. By employing KPFM and NRA techniques in ASSB research, our knowledge of space charge layer evolution at the solid electrolyte electrode interface is more comprehensive, even beyond the investigation of space charge layers.   Press Release.

Adventure: Lecture Tour in Asia (October 2025)

I visited groups at Tohoku University (Japan), NIMS (Japan), Xuzhou China University of Mining and Technology in Xuzhou, University of Science and Technology of China in Hefei and Hohai University in Changzhou.

Congratulation: PhD to Chirag Hinduja (July 2025)

Chirag was awared with a PhD from TU Darmdstadt for his thesis titled: Forces on Three-Phase Contact Line of Sliding Drops. On left side: Prof.Dr. Peter Stephan, on right side Prof. Dr. Hans-Jürgen Butt.

Award: Sajjad Shumaly (June 2024)

He presented his work titled "Estimating Sliding Drop Width Using Recurrent Neural Networks" at the World Conference on Data Science and Statistics June 17 - 19, 2024 in Amsterdam (Netherlands) and won the best contribution award of the entire conference. Congratulation!

Adventure: Bodywork for a contribution to Max Planck Research

Christian Schneider wrote an contribution of our reserach on Tactile Drops (in German: Tropfen mit Tastsinn).
 

The article required a special photo shooting that impressively depicts the contact of water with different surfaces. surfaces. Several liters of water poured over the three researchers several times - a real commitment to the Institute's public relations work of the institute. More details here: https://www.mpg.de/20899769/MPF_2023_3.

Award: Chirag Hinduja (March 2024)

He presented his work titled "Electro Drop Friction Force Instrument" at the APS meeting March 3 - 8, 2024 in Minneapolis (US) and won the best contribution award in the session "tutorial for authors and referees for physical review journals". Congratulation!

Award: Congratulations to Franjo Weber (September 2023)

He won the best poster prize at the 4th World Conference on Solid Electrolytes for Advanced Applications: Garnets and Competitors (4-7 September 2023) in Tromso, Norway.
 

His poster contributes to understanding the evolution of lithium dendrites in garnet materials by interpreting operando KPFM measurements. Lithium dendrite growth is a major drawback hindering the development of reliable all-solid-state lithium metal batteries based on inorganic solid electrolytes. These dendrites are often found at the grain boundaries of the solid electrolyte, as observed by ex-situ post mortem measurements of battery components.However, it is not understood where do dendrites nucleate and why do they grow? To gain insight in both aspects, we performed operando Kelvin Probe Force Microscopy (KPFM) measurements on a Li_6.25Al_0.25La₃Zr₂O₁₂ garnet-type solid electrolyte during charging and discharging of the battery. We show that KPFM maps the Galvani potential (inner electrostatic potential) of the solid electrolyte during operation. We measured a drop in the Galvani potential at the grain boundaries close to the lithium metal electrode during plating. We attribute the Galvani potential drop to a preferential accumulation of electrons at the grain boundaries. Based on our results, we present a mechanistic model that explains the preferential growth of lithium dendrites at grain boundaries and their penetration into inorganic solid electrolytes. The presented work partially bases on the work published by Chao Zhu, Till Fuchs, Stefan A.L. Weber, Felix. H. Richter, Gunnar Glasser, Franjo Weber, Hans-Jürgen Butt, Jürgen Janek, Rüdiger Berger, Nature Communications 14, 1300 (2023) .

Award: Congratulations to Xiaomei Li (August 2023)

She won the best presentation award at the Droplet Conference 2023 in Bejjing.
 

Her presentation summarizes the fast-release kinetics of a pH-responsive polymer measured by dynamic contact angles. Surface adaptation is a dynamic process when a droplet is sliding over a pristine surface. Surface adaptation may lead to changes in surface energy which can be measured by contact angles. The conformation of polymers can play an important role in releasing active agents, e.g. drugs, upon an external stimulus. In this work, we investigate the fast-release kinetics of 8-hydroxyquinoline from a pH-responsive random copolymer composed of methyl methacrylate and 8-quinolinyl-sulfide-ethyl acrylate by hydrolysis. Combing dynamic contact angle measurement with the adaptation model allows exploring the release kinetics on a much shorter time scale down to µs. The presented work bases on the work published by Xiaomei Li, Krisada Auepattana-Aumrung, Hans-Jürgen Butt, Daniel Crespy, Rüdiger Berger, Chemical Physics Letters 158, 144901 (2023).