It was an honor to meet and talk with Saarland Minister-President (prime minister) Tobias Hans during his visit to INM. We discussed our research on alternative batteries and energy-efficient lithium-ion-battery recycling. Read more about the visit online and on LinkedIn (our LinkedIn, the INM LinkedIn, and the PM’s LinkedIn). We are grateful that, the very next day, the state TV broadcasting station Saarländischer Rundfunk paid us also a visit and made a 2 min clip about our recycling project, kindly financially supported by the EU via European Regional Development Fund. The clip aired during the very popular segment “Aktueller Bericht“, and you can watch it via access to the SR Mediathek.
New review paper published in Electrochemistry Communications. Energy-efficient technologies for the remediation of water and the generation of drinking water are essential to sustainable technologies. However, we cannot have sustainable energy technology without sustainable water remediation (and vice versa). Among many possible applications, large-scale seawater desalination is a much-needed step towards large-scale hydrogen generation via power-to-gas. However, this can only be considered sustainable when done effectively and energy-efficiently. Electrochemical desalination technologies are promising alternatives towards established methods, such as reverse osmosis or nanofiltration. In the last few years, hydrogen-driven electrochemical water purification has emerged. This joint Israeli-German review article explores the concept of desalination fuel cells and capacitive-Faradaic fuel cells for ion separation. This work was done in collaboration with the research teams of Matthew Suss and of Yuri Gendel (both at Technion, Israel).
New paper published in Cell Press Physical Science on the use of sub-nanometer pores for capacitive deionization to enable membrane-free seawater desalination. Big pores are mighty powerful when it comes to capacitive deionization (CDI). CDI is highly appreciated as a potentially energy-efficient desalination technology, rendering saline water into desalinated (potable/processable) water. However, once we move from saline media with low salt concentrations (like in brackish water regimes) towards higher salt concentrations (as you find in ordinary seawater), CDI become less attractive: the desalination capacity and charge efficiency (think of it as salt removal per invested charge) drop drastically. This issue is linked to the limited permselectivity of carbon pores commonly found in CDI electrodes. Put simply: the invested charge is not only used for adding “extra “ions into the pore (thereby: lowering the feedwater ion concentration) but also to eject ions that are already inside the pore (which basically increases the ion concentration in the effluent stream). We can address this issue by implementing an ion exchange membrane (adding costs and a more complex design) or using charge-transfer materials (giving rise to desalination batteries). But is there a way to keep low-cost, nanoporous carbon and still enable direct, membrane-free seawater desalination? The answer is a resounding YES. In our 2020 paper in Sustainable Energy & Fuels, we showed already the proof of concept of using quasi-ionophobic, and thereby permselective, carbon pores. Now, our work extends the scope and demonstrates this effect’s intricate pore size dependency. The key is a subtle play of pore size and hydrated ion diameter, which allows the pore to only uptake (extra) ions once an electric potential is applied. This work was a great collaboration with the team of Guang Feng at HUST, China, and Christian Prehal at ETH Zürich that puts together simulation and experimental work.
New paper published in Desalination with the title “Particle size distribution influence on capacitive deionization: Insights for electrode preparation”. Our work explores the particle size dispersity of commercially available activated carbon. No activated carbon powder is “perfect”, that is, every powder contains (a bit) larger and smaller particles. Size separation allows to capitalize on “one powder – several sizes” aspect. Comparing mixed-sized, small-size, and large-size activated carbon classes (of the same activated carbon powder), our work shows that large particles suffer from ion transport limitation, but so do electrodes composed of (well-packed) small particles. The best performance was found to be in the middle: a hierarchic mixture of larger and smaller activated carbon particles.
New paper published in ACS Applied Materials & Interfaces. This work in collaboration with the teams of Markus Gallei and Guido Kickelbick (both at Saarland University) explores shear-induced co-assembly as a step towards creating unique (ordered) materials. The latter can be conveniently converted to metal oxide / carbon hybrids via thermal annealing. For example, titanium niobium oxide / carbon obtained this way profided 335 mAh/g at 10 mA/g and a capacity retention of 84% after 1000 cycles at 250 mA/g.
New paper published in the AAAS journal Research on the use of hollow / nanosheet / needle-like cobalt hydroxide for the use for high performance electrochemical desalination. This material architecture allows for rapid ion removal and high stability in absence of strain-build-up. This work was done in collaboration with the team of Jie Ma at Tongji University.
New paper published in Journal of Physical Chemistry C on the origin of better long-term electrochemical performance of silica-pillared MXene. This unique material provides enhanced performance as an lithium-ion battery electrode (ca. 300 mAh/g at 20 mA/g rate). Although larger volume changes are seen for the pillared MXene, this is not a detriment to the cycling stability. This work was done in collaboration with the teams of Nuria Tapia-Ruiz (Lancaster University) and Nuno Bimbo (now: University of Southampton).
New paper published in ACS Applied Polymer Materials on the use of redox-responsive 2-aminoanthraquinone core-shell particles for structural colors and carbon capture. This work was done in collaboration with the group of Markus Gallei (Saarland University), Karin Jacobs (Saarland University), and T. Alan Hatton (MIT).
We are very fortunate to welcome new group members to our team!
- Bowen Dong is joining us as a Ph.D. student supported by the China Scholarship Council. Bowen has graduated from China University of Geosciences (China) and will be working on MXene batteries.
- Jerome Baudin is joining us as a EEIGM student. Jerome is enrolled in the EEIGM program and his last host University in this international program was Université de Lorraine (Nancy, France). He will be working on layered metal oxide batteries.
- Lexane Deligniere is joining us as a EEIGM student. Lexane is enrolled in the EEIGM program and her last host University in this international program was Université de Lorraine (Nancy, France). She will be working on water desalination with layered metal oxides.
- Xiao Zhang is joining us as a EEIGM student and as a student intern. Xiao is enrolled in the EEIGM program and her last host University in this international program was Saarland University. She will be working on MXene desalination.