New paper published on “Life after death: Re-purposing end-of-life supercapacitors for electrochemical water desalination” in Batteries & Supercaps.

Even the best supercapacitor, at some point, will reach its end-of-life. With limited amounts of precious elements (unlike lithium-ion batteries), elemental extraction of the active material’s components is not really attractive for supercapacitors. More interesting is to see the direct recycling of the active component, meaning mostly activated carbon in its various forms. But what else can we do with nanoporous carbons from spent supercapacitors?

Our work explores the re-purposing of end-of-life commercial supercapacitors as electrochemical desalination cells, using them for capacitive deionization. The research demonstrates that the carbon electrodes from disassembled supercapacitors can be modified and effectively used for water desalination via capacitive deionization. The modifications ranged from NaOH-etching to CO₂ activation, showing varying degrees of efficiency and stability in desalinating low-salinity water. As a concept study, we show limitations and perspectives toward re-purposing in the context of electrochemical desalination.

New paper on solvation effects inside carbon nanopores during electrosorption published in Carbon.

Our British-German study explores the solvation effects on ion adsorption and electrosorption within carbon micropores, employing nuclear magnetic resonance (NMR) spectroscopy to gain insights. Our data investigate how ionophilicity and ionophobicity – the tendency of ions to be uptaken by uncharged nanopores – affect the partitioning behavior of ions. The nanopore diameter significantly influences ion adsorption, with narrower pores creating higher barriers for ion entry. The research also reveals that ion-specific solvation effects impact on the charge storage mechanism, with ionophilic systems favoring counter-ion adsorption, while ionophobic systems tend toward co-ion ejection under applied voltage.

In a broader context, this work contributes to the ongoing efforts to enhance the efficiency of energy storage technologies, especially fast charge/discharge capable supercapacitors. By unraveling the interactions between ions and carbon nanopores, the research provides insights that could inform the development of more effective materials for supercapacitors and capacitive deionization, key components in sustainable energy systems.

Acknowledgments: Ryan J. Bragg (Lancaster University), Kieran Griffiths (Lancaster University), Imgon Hwang (The University of Manchester), Mantas Leketas (The University of Manchester), Kacper Polus (The University of Manchester), Robert Dryfe (The University of Manchester), and of course John M. Griffin (Lancaster University).#

New paper published on “Freestanding Films of Reduced Graphene Oxide Fully Decorated with Prussian Blue Nanoparticles for Hydrogen Peroxide Sensing” in ACS Omega.

This work explores freestanding graphene/Prussian blue (PB) electrodes for detecting hydrogen peroxide (H₂O₂). Using a two-step method, we synthesized reduced graphene oxide/PAni/Fe₂O₃ freestanding films, followed by electrochemical deposition of PB nanoparticles. This approach balances the structure of the electrodes with their electrochemical performance for H₂O₂ sensing.

Thanks to all authors for this Brazilian-German collaboration: Vitor H. N. Martins, Monize M. da Silva, Daniel A. Gonçalves, Samantha Husmann, and Victor H. R. Souza.

New paper published in Energy & Environmental Materials. A few years ago, then-PhD-student Zhang Yuan explored with us the adoption of a fuel cell for continuous water desalination. Basically, a fuel cell can be “fooled” to desalinate an inflowing water stream by replacing the common proton exchange membrane with a flow channel, contained within a pair of an anion and a cation exchange membrane. Thereby, while consuming fuel (e.g., hydrogen and oxygen), electricity is generated and water desalted all at once. Now, we have moved one step further: making fuel cell desalination lithium-ion selective for direct lithium-ion extraction from seawater or mine water (other water media work too).

Our team, lead by Cansu Kök, and with Lei Wang, Jean Gustavo De Andrade Ruthes, Antje Quade (from the Leibniz Institute for Plasma Science and Technology (INP Greifswald) e.V.), and Matthew Suss (from Technion – Israel Institute of Technology; now at Form Energy), has developed the first-ever fuel cell system designed specifically for continuous lithium-ion extraction. This approach utilizes a lithium superionic conductor membrane alongside advanced electrodes to enhance efficiency and environmental sustainability.

A titania-coated electrode in our fuel cell achieves a 95% lithium-ion purity and produces 10.23 Wh of energy per gram of lithium. Thanks to atomic layer deposition, we’ve significantly improved the electrode’s uniformity, stability, and electrocatalytic activity, maintaining stability even after 2000 cycles.

New paper in Carbon on hydrogen densification in carbon nanopore confinement: Insights from small-angle neutron scattering using a hierarchical contrast model from our long-term collaboration with Oskar Paris (Montanuniversität Leoben).

New battery published in ACS Applied Materials & Interfaces on hybridization of carbon spherogels with titanium oxide and sulfur enables high performance lithium-ion battery electrodes. As a result from our research project with Michael Elsaesser from the Paris Lodron Universität Salzburg, we introduce a novel approach to enhancing lithium-ion battery electrodes. We have successfully combined titanium oxide and sulfur with carbon spherogels, achieving high performance in terms of stability and capacity. Our method resulted in electrodes combining high charge storage capacity and electrical conductivity, while maintaining a core-shell morphology. The process involved producing carbon spheres encapsulating titania and sulfur using a template-assisted sol-gel route, followed by thermal treatment with hydrogen sulfide gas. This treatment fully preserved the microporous hollow sphere architecture of the carbon shells, facilitating sulfur deposition and titania crystal protection.

New paper published in Energy Advances from our continued collaboration with Michael Elsaesser (Paris Lodron Universität Salzburg) on carbon spherogels. Custom-designed nanoporous carbon materials enhance sustainable electrochemical technologies by offering better performance and efficiency. Carbon spherogels, which are highly porous carbon aerogel materials made up of a network of hollow carbon nanospheres with consistent diameters, are particularly promising. They offer unique advantages, including superior electrical conductivity, customizable porosity, adjustable shell thickness, and extensive surface area. In this work, we present a new, eco-friendlier approach to producing carbon spherogels using a sol-gel process that templates resorcinol-formaldehyde (RF) with polystyrene spheres in an organic solvent. By adjusting the molar ratio of resorcinol to isopropyl alcohol (R/IPA) and the polystyrene concentration, we identified the optimal conditions for creating carbon spherogels with tunable wall thicknesses. A simplified solvent exchange method from deionized water to isopropyl alcohol was developed to reduce surface tension in the gel’s pores, making this method both time and cost-efficient. The use of isopropyl alcohol, with its lower surface tension, allows for solvent extraction at room temperature and direct carbonization of RF gels with less than 20% loss in specific surface area compared to those dried supercritically. The resulting materials have specific surface areas ranging from 2300 to 3600 m²/g, as confirmed by transmission and scanning electron microscopy, which also demonstrated their uniform, hollow spherical network structure. Notably, these carbon spherogels act as high-performance electrodes for energy storage in supercapacitors, achieving a specific capacitance of up to 204 F/g at 200 mA/g with a 1 M potassium hydroxide (KOH) solution as the electrolyte.

New paper published in Journal of Molecular Liquids on binary ionic liquid supercapacitors. There is much to learn from simulation when it comes to understanding nanoscaled ion electrosorption of ions within carbon nanopores. Especially when it comes to the behavior of ionic-liquid-based supercapacitors which promise an extended potential window, and consequently, enhanced energy ratings. Ionic liquids, in absence of a solvent, and with enhanced ion-ion interactions, present an intriguing model system to study size effects in more complex electrolytes with more than just one cation. Our findings, combining simulation and experimental data, reveal the enhanced capacitance of single nanopores and nanoporous electrodes using binary electrolytes. 🔬⚡
I’d like to extend my heartfelt gratitude to our research partners (Taras Verkholyak, Dariusz Gołowicz, Andrij Kuzmak, Svyatoslav Kondrat) and my team (Anna Seltmann, Emmanuel Pameté)! And I am proud to share that this is a collaborative Polish 🔴⚪ German ⚫🔴🟡 Ukrainian paper 🔵🟡.

New paper published in Advanced Functional Materials in lead by the teams of Michael Naguib and Agnieszka Maria Jastrzębska. MBenes, a new class of post-MXene materials, stand out due to the inclusion of boron in their structure, replacing carbon and nitrogen. This distinct composition provides a fresh perspective on boron’s impact in two-dimensional materials. The challenge in processing MBenes lies in the wet-chemical etching and delamination of the initial MoAlB phase, mainly due to the strong bonding of aluminum with surrounding elements. This research successfully addresses this challenge by treating MoAlB with an aqueous HCl/H₂O₂ solution for varying durations of 24 hours, 48 hours, and 72 hours. The process results in individual, single-to-few layered MBene flakes, particularly notable in the 48-hour etched sample. Detailed analysis through a combination of theoretical and experimental X-ray diffraction techniques reveals that the optimally delaminated 48-MBene possesses a Mo2B2 orthorhombic lattice structure. Additionally, the formation of Mo oxide within these MBenes introduces both direct (1.2 eV) and indirect (0.2 eV) optical band gaps, significantly enhancing their photocatalytic efficiency. This is especially evident in their ability to decompose methylene blue, a commonly used organic pollutant, achieving about 90% decomposition under UV and simulated white light, with a rate thrice as fast as some MXene hybrids. Moreover, the 48-MBene shows exceptional capability in harnessing the full spectrum of visible light to generate reactive oxygen species. In contrast, the 24-hour and 72-hour treated MBenes exhibit lesser performance due to incomplete delamination or oxidation. These findings pave the way for using MBenes in environmental cleaning applications, highlighting their potential in addressing water contamination issues.

New paper published in ACS Nano. Our work explores horn-like pore entrance geometries that boost the overall charging dynamics and charge storage of nanoporous supercapacitors. This work was in collaboration with Guang Feng (HUST).