bluuebunny/crossref_metadata_2025_split huggingface dataset:
Square Wave Electrogravimetry Monitors Transient Submonolayer Adsorption of Redox-Active Molecules with a Precision of Less Than 1% of a Monolayer
Authors: Leppin Christian , Langhoff Arne , Johannsmann Diethelm 
Published: August 2024

Square wave voltammetry on electrolytes containing the reversible redox pairs flavin adenine dinucleotide (FAD) and methyl viologen (MV) was complemented by a new form of acoustic microgravimetry. The analytes FAD and MV have promising applications in bacterial fuel cells and redox flow batteries. The instrument operates similarly to a quartz crystal microbalance with dissipation monitoring (EQCM-D). It reports shifts in resonance frequency and half bandwidth on several overtones. Compared to the existing instruments, the time resolution was improved by a factor of 40 down to 2.5 ms by multifrequency lockin amplification, which is important for the analysis of the transients in electrochemistry. The frequency noise after accumulation was reduced below 10 mHz ≙ 0.12 ng/cm2 ≙ 1.2 pm (assuming ρ = 1 g/cm3) by employing modulation and averaging. Square wave modulation of the electrode potential is superior to linear ramps (cyclic voltammetry) because it reduces the contribution of non-Faraday currents and, also, improves sensitivity. The shifts of frequency,Δf, and half bandwidth, ΔΓ, are in line with the Sauerbrey prediction (Δf/n
≈const. and ΔΓ/n < -Δf/nwith n the overtone order). Small deviations (Figure B and D) presumably are caused by the layer’s softness. The apparent shear modulus, G
app, of this layer is in the GPa range. The frequency difference, Δf/n|CT (Figure E), amounts to an apparent mass transfer rate. Plots of Δf/n|CT versus potential sometimes show curves similar to the electric current as observed for e. g. MV. For FAD, the results obtained depended on pH and the apparent mass transfer rates are much different from the current (Figure C and E). This difference is most likely caused by adsorbed molecules that are intermediates of the underlying two-electron process. The explanation is further corroborated by the response time of the QCM signals being much larger than the RC time of double layer recharging as determined with EIS. An interpretation in terms of adsorption/desorption is more plausible than an interpretation in terms of changed viscosity in the diffuse double layer.[1]

Caption: Currents and frequency shifts obtained on a solution containing FAD. Df/n|av evidences the preferred adsorption of the intermediate state (FADH).
References
[1] Leppin, Christian; Langhoff, Arne; Johannsmann, Diethelm. Square-Wave Electrogravimetry Combined with Voltammetry Reveals Reversible Submonolayer Adsorption of Redox-Active Ions. 2022, 94 (28), 10227–10233.

Figure 1
Alternative Technique to RDE to Evaluate Photoelectrocatalysts for ORR
Authors: García Caballero Ariadna D , Diaz-Real Jesus Adrián 
Published: August 2024

The scarcity of fuels due to the growing energy demand has encouraged research into topics such as energy conversion with materials that can take advantage of solar energy. Such situations have promote the emergence of various new materials to assist reactions of special interest such as oxygen reactions. (Oxygen Reduction Reaction, ORR and Oxygen Evolution Reaction, OER). Thus, numerous materials are emerging with the photoelectrocatalytic activity towards OER and ORR reactions. To evaluate the photo-assisted OER requires technical conditions that a rotating disk electrode (RDE) does not satisfy.
In this work we present an alternative technique to RDE by adapting a flow in a microfluidic platform to satisfy the limit current while it can be irradiated and thus evaluate the photoelectocatalysis of a semiconductor that has the characteristic of a photoelectrocatalyst.
To make the comparison, a glassy carbon electrode (GCE) was used using the Pt/C system in a three-electrode cell designed with a microfluidic channel where we found that the mass flow is comparable to rpm.
A Unified Multiscale Framework for Simulating Electrochemical Gas Evolving Reactions
Authors: Zhang Muhan , Li Weihong , Zhang Lenan 
Published: August 2024

The presence of gas bubbles in electrochemical systems, such as water-splitting, significantly increases overpotential and diminishes energy efficiency. High-fidelity simulation holds significant promise to gain mechanistic understanding of bubble dynamics and guide high-performance electrolytic cell design. However, the extreme length scales involved into electrochemical gas evolving systems, from sub-nanometer dictated by the electrical double layer (EDL) to a few centimeters featured by the electrolytic cell, have posed a huge challenge to enable sufficient numerical accuracy and superior computational efficiency. As a result, state-of-the-art numerical approaches either can only simulate a nanoscale computational domain or neglect the electrochemical kinetics within the EDL, impeding an in-depth understanding of how bubbles could intervene with the electrochemical process.
In this work, we demonstrate a full-field simulation approach of electrochemical gas evolving reactions that can capture the electrochemical kinetics of the EDL in a centimeter-scale electrolytical cell with the presence of micro-to-millimeter scale bubbles. To resolve all characteristic length scales, the EDL is geometrically decoupled from the electrolytical cell but physically coupled with the bulk electrolyte and gas bubble through a quasi-1D treatment. As a result, the Nernst-Planck-Poisson-Boltzmann model can be rigorously solved in both the EDL and the rest of the electrolytical cell with highly affordable computational cost. Taking hydrogen evolution reaction as an example, we validated our approach by comparing with a variety of existing numerical and experimental results. For the first time, the impact of bubbles on the increase of overpotential observed in experiments can be quantitatively confirmed through numerical simulation. More notably, compared to state-of-the-art high-fidelity simulations, our approach exhibits a remarkable computational efficiency, which reduced the computational time by a factor of 100,000. This work provides a viable solution to simulate electrochemical gas evolving reactions with highly desirable numerical accuracy and unprecedented computational efficiency, which can serve as an effective tool to understand bubble dynamics and guide the design of next-generation electrolytical cells.
Deep Learning Assisted High Resolution Microscopy Image Processing for Phase Segmentation in Functional Composite Materials
Authors: Raghavendran Ganesh , Zhang Minghao , Meng Shirley 
Published: August 2024

In the domain of battery research, the processing of high-resolution microscopy images is a challenging task, as it involves dealing with complex images and requires a prior understanding of the components involved. The utilization of deep learning methodologies for image analysis has attracted considerable interest in recent years, with multiple investigations employing such techniques for image segmentation and analysis within the realm of battery research. However, the automated analysis of high-resolution microscopy images for detecting phases and components in composite materials is still an underexplored area.
The presentation discusses the formulation of a sophisticated deep learning-assisted workflow tailored for the meticulous processing of high throughput, high-resolution microscopy images to detect, map and analyze the evolution of periodic components from a stack of high-resolution Transmission Electron Microscopy (TEM) image. The developed methodology employs deep learning techniques and utilizes Fast Fourier Transform (FFT) patterns extracted from TEM images to analyze feature positions and ascertain periodic components. The approach incorporates innovative strategies to process high-resolution images, capitalizing on the symmetry within FFT patterns to enhance model performance. This methodology streamlines the detection and mapping of components while the intensity profiles derived from the frames provide valuable insights into the evolution of periodic components within the sample during the imaging period.
High-resolution images obtained through a beam damage analysis investigation of lithium fluoride (LiF), a prevalent constituent within the solid-electrolyte interphase (SEI) of cycled lithium metal anodes, were employed to assess the program's scalability and robustness. The study elucidated decomposition products and their spatial distribution. Furthermore, the intensity profile of periodic components detected across multiple frames aided in evaluating the beam damage mechanism of the LiF component.
Our research has resulted in an open-source Python GUI program that the research community can freely access and experiment with.

Figure 1
(Invited) First Principles Treatments of Heterogeneous Electrocatalysis – Reactivity Trends and Electrocatalyst Structure
Authors: Morankar Ankita , Deshpande Siddharth , Deshmukh Gaurav , Ghanekar Pushkar , Zeng Zhenhua , Greeley Jeffrey 
Published: August 2024

Advances in the theoretical understanding of electrochemical systems have, over the past decade, led to growing use of periodic Density Functional Theory studies to treat a surprisingly large ensemble of electrocatalytic reactions, ranging from carbon dioxide electroreduction to oxygen evolution. Many such studies have employed simplified models of the electrochemical environment to determine reactivity trends across a broad space of catalytic materials, while other efforts have focused on developing detailed descriptions of electrochemical phenomena, such as the structure of electrochemical double layers, on model catalyst structures. An emerging challenge is to combine these approaches to ultimately enable theoretical design of electrocatalysts for reactions of significantly expanded chemical and materials complexity.
In this talk, I will begin by discussing how we have applied strategies from computational heterogeneous catalysis to design enhanced electrocatalysts for the classic oxygen reduction reaction. In such treatments, we have effected highly detailed analyses of the catalyst surface structure and have employed machine learning-based methods to describe interactions between the various ORR reaction intermediates that are present at significant surface coverages. I will then explore challenges in obtaining more detailed descriptions of the electrocatalytic reaction environment, including the structure of catalysts with solid/solid interfaces, the distribution of charges in electrochemical double layers, and the structure and entropy of solvents near the electrocatalyst surface. I will conclude with some perspectives on how these complexities may be incorporated into traditional computational catalyst screening approaches to identify improved materials for more complex electrocatalytic systems.
Physics-Based Impedance Model for Understanding Proton Transport in PEM Fuel Cells
Authors: Ince Alper Can , Kort-Kamp Wilton , Liyanage Wipula Priya Rasika , Spendelow Jacob S. , Pasaogullari Ugur , Borup Rod L. , Komini Babu Siddharth 
Published: August 2024

The electrochemical impedance spectroscopy (EIS) diagnostics using H2/N2 operation condition developed for fuel cell is useful tools to estimate the catalyst layer (CL) proton resistance. Currently, the resistance is estimated by fitting the measured EIS data to an equivalent circuit model. However, it is challenging to correctly determine the transmission line circuit and accurately estimate the proton resistance [1]. Moreover, the capacitive and resistance elements in the transmission line model are assumed similar throughout the CL even if there is nonhomogeneous distribution of ionomer. To understand the EIS response in CL, we present a physics-based model. Utilizing the model, we are able to investigate the H2/N2 cell impedance response under various operating conditions. The continuum scale model will be combined with agglomerate scale model to provide a detail study of the electrode parameters like ionomer loading and ionomer coverage The hybrid theoretical model allows us to study the effect of nonhomogeneous CL and its corresponding EIS response.

Acknowledgement

This research is supported by U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office, through the Million Mile Fuel Cell Truck Consortium (M2FCT).

References:

[1] Malevich, D., Jayasankar, B. R., Halliop, E., Pharoah, J. G., Peppley, B. A., & Karan, K. (2012). On the determination of PEM fuel cell catalyst layer resistance from impedance measurement in H2/N2 cells. Journal of the Electrochemical Society, 159(12), F888.
[2] Liu, Y., Murphy, M. W., Baker, D. R., Gu, W., Ji, C., Jorne, J., & Gasteiger, H. A. (2009). Proton conduction and oxygen reduction kinetics in PEM fuel cell cathodes: effects of ionomer-to-carbon ratio and relative humidity. Journal of The Electrochemical Society, 156(8), B970.
In-Situ Liquid-Electrochemical X-Ray and Electron Microscopy for Multi-Modal Energy Materials Characterization
Authors: Parkin Calvin , Mefford Tyler , Lim Jongwoo , Yoon Aram , Serra-Maia Rui , Kumar Pawan , Chee See Wee , Chueh William C. , Alsem Daan Hein , Salmon Norman , Stach Eric A. 
Published: August 2024

In-situ liquid cell electron and x-ray microscopy have enabled dynamic studies of electrochemical reactions in energy materials and revealed relationships between the performance, structure, and chemical composition of these material systems. Such fundamental relationships are critical to improving the performance of batteries, catalysts, and other energy materials. Growing research interest in energy materials systems has accelerated the development of in-situ liquid-electrochemical microscopy techniques into mature and robust characterization workflows using novel and versatile scientific hardware.
Multiple characterization techniques or in-situ processing steps are often required to fully understand the mechanisms governing the behavior of energy materials for all relevant length scales and environmental conditions. A multi-modal workflow combining in-situ liquid-electrochemical transmission electron, X-ray synchrotron and scanning electron microscopy methods is presented. The breadth of research applications is discussed, including the study of chemical dynamics and structural changes to micron-scale LixFePO4 battery particles during lithium-ion insertion/extraction, electrocatalytic behavior of β-Co(OH)2 platelet particles, and electrochemical oxidation of copper nanoparticles under reductive electrolytic conditions. New insights into these materials systems provided by these experiments will directly inform the development of predictive models for material performance and guide improvement of material design and synthesis.
New scientific hardware and method development has been critical to in-situ nano-scale liquid cell microscopy and spectroscopy of electrochemical systems. Therefore, best-practice hardware and method design and development for these in-situ liquid-electrochemical microscopy experiments are also discussed. The connections between potentiostat, holder, and on-chip leads must be carefully considered with respect to different ground potentials, and the incorporation of real bulk-scale reference electrodes in this hardware has yielded quantitatively higher fidelity data with less degradation from further electrochemical cycling. Heating the sample or illuminating with light during in-situ electrochemical data collection has begun to further expand the range of environmental conditions that can be incorporated into experiments.
(Invited) Bragg Coherent Diffraction Imaging Studies of Composition Distribution and Strain in Catalytic Alloy Nanoparticles
Authors: Kawaguchi Tomoya 
Published: August 2024

Compositional distribution, strain, and defects in alloy nanoparticles significantly affect the catalytic properties for a wide range of applications such as gas reforming, fuel cells, electrolysis, etc. while various alloy compositions of nanoparticles have been investigated to improve performance and reduce the amount of precious metals used. It was reported that the composition distribution of the alloy particles, expectedly homogeneous in the whole particle, changed dynamically depending on the operating environment, resulting in altering the catalytic activity [1]. Furthermore, defects such as dislocations, grain boundaries, and elastic strain of the crystalline lattice also significantly affect catalytic properties. Since these factors dynamically change and evolve under operating environments, in situ measurements are essential to reveal these factors and ultimately to exploit them to enhance the catalytic properties.
Bragg coherent diffraction imaging (BCDI) is a lens-less imaging method that measures speckle patterns near Bragg diffraction from a crystalline sample and reconstructs the 3D particle images. Since Bragg diffraction is inherently sensitive to displacements of the crystal lattice, BCDI yields the displacement field within the sample as well as the electron density, i.e., the “shape” of the particle. This displacement field information further allows us to evaluate strain distribution, dislocations, and composition distribution in the particle. BCDI is also advantageous for in situ measurements because the 3D image can be obtained by rotating the sample by only a few degrees, which eases the geometrical constraint of an electrochemical cell for the measurement. This is in contrast to conventional 3D imaging techniques such as X-ray CT, which usually requires 180 degrees of sample rotation.
Furthermore, it is expected that the measurement capabilities of BCDI will be rapidly advanced by upgrading synchrotron radiation facilities such as APS-U, which delivers high-flux coherent X-rays. This should expand the applications of BCDI to wider electrochemical materials.
In this presentation, we will briefly overview the principle of BCDI followed by specific examples of in situ measurements of catalytic alloy particles [2-4] conducted at 34-ID-C at Advanced Photon Source.
[1] F. Tao et al., Science 322, 932 (2008).
[2] T. Kawaguchi et al., Phys. Rev. Lett. 123, 246001 (2019).
[3] T. Kawaguchi et al., Nano Lett. 21, 5945 (2021).
[4] D. Sheyfer, R. G. Mariano, T. Kawaguchi, et al., Nano Lett. 23, 1 (2023).
High-Density, Low-Tortuosity Sulfur Electrodes for High Energy Lithium–Sulfur Batteries
Authors: Shi Lili , Xiao Jie , Liu Jun , Lu Dongping 
Published: August 2024

Lithium–sulfur (Li–S) batteries have attracted significant attention due to their promising theoretical energy and cost-effectiveness.[1] While recently studies have predominantly focused on increasing sulfur mass loading and utilization rate for high specific energy, there remains a noticeable gap in addressing the intrinsic challenge of improving volumetric energy density.[2] This challenge arises as many Li-S investigations rely on highly porous electrodes.[3] Here, we employ a shear-rolling approach to prepare free-standing electrodes characterized by high density (porosity<15%), low tortuosity, and substantial S content (>70%). The incorporation of a vascular-like porous network, facilitated by a pore soft template, plays a pivotal role in achieving high sulfur utilization (>1000 mAh g-1) in high-loading electrodes (>4 mg cm-2) under lean electrolyte condition (E/S 4 mL g-1). This approach results in an extraordinarily high volumetric energy density (668 Wh L-1 of dry cell) when applied to practical Li–S pouch cells. Our study underscores that realizing high volumetric energy in Li–S cell can be achieved by rationalizing the dense electrode architecture. Furthermore, the shear-rolling approach holds broad applicability for fabricating high-energy electrodes using porous or nanoparticle materials with desirable structures. Details of the progress will be discussed at the conference.
References
[1] Y. Cao, M. Li, J. Lu, J. Liu, K. Amine, Nat Nanotechnol
2019,
14, 200-207.
[2] S. Dorfler, H. Althues, P. Hartel, T. Abendroth, B. Schumm, S. Kaskel, Joule
2020,
4, 539-554.
[3] L. L. Shi, S. M. Bak, Z. Shadike, C. Q. Wang, C. J. Niu, P. Northrup, H. K. Lee, A. Y. Baranovskiy, C. S. Anderson, J. Qin, S. Feng, X. D. Ren, D. Y. Liu, X. Q. Yang, F. Gao, D. P. Lu, J. Xiao, J. Liu, Energy & Environmental Science
2020,
13, 3620-3632.
Understanding the Mechanical Behavior of Sulfide Solid Electrolyte Membranes for Practical Applications in All-Solid-State Batteries
Authors: Kim Mokwon , Hwang Seung-Sik , Ku Junhwan , Lee Yong-Gun 
Published: August 2024

All-solid-state batteries (ASSBs) hold great promise as next-generation energy storage systems due to their enhanced stability and high energy density compared to traditional lithium-ion batteries. This improvement stems from the use of a solid electrolyte (SE) instead of a highly volatile liquid electrolyte and the incorporation of a lithium metal anode. In general, sulfide-based SSBs require adequate pressurization conditions to establish an intimate interface between the solid particles, ensuring a continuous electron/ion conduction path. At the cell level, maintaining external stack pressure during operation is crucial to preserve conformal solid-solid contact. Furthermore, when scaling up, fabrication pressure should be carefully considered to enhance electrode densification without causing damage. In particular, the fabrication of thin, robust, and scalable SE membranes faces practical challenges due to a limited amount of polymeric binder and the low intrinsic ductility of SEs after densification. Understanding the mechanical behavior of these SE membranes is essential to ensure their structural stability during manufacturing.
In this study, we systematically examined the mechanical properties of SE and SE membranes. The deformability of various types of sulfide SEs was assessed using a powder compaction test, departing from the commonly used indentation method. The yield pressure, which indicates the deformability of the SE powder, is influenced by the composition and synthesis conditions of the SEs. The stress-strain behaviors of the SE membranes were obtained through tensile and flexural tests for both as-prepared and pressed samples, respectively. The tensile and bending behaviors of the SE membranes strongly depend on the combination of the SE and polymeric binder. The utilization of a ductile SE and a rubbery polymer binder can enhance the flexibility and ductility of the membrane, leading to increased densification degree and low interfacial resistance even under lower fabrication pressure. The details of cell configuration, fabrication procedure, and the resulting performances of the cell will be discussed in this talk.