bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrolyte Dependence of Li+ Transport Mechanisms in Small Molecule Solvents from Classical Molecular Dynamics
Authors: Aggarwal Abhishek , Crabb Emily , Shao-Horn Yang , Leverick Graham , Grossman Jeffrey
Published: December 2024

As demands on Li-ion battery performance increase, the need for electrolytes with high ionic conductivity and a high Li+ transference number (tLi) becomes crucial to boost power density. Unfortunately, tLi in liquid electrolytes is typically <0.5 due to Li+ migrating via a vehicular mechanism, whereby Li+ diffuses along with its solvation shell, making its diffusivity slower than the counteranion. Designing liquid electrolytes where the Li+ ion diffuses independently of its solvation shell is of significant interest to enhance the transference number. In this work, we elucidate how the properties of the solvent influence the Li+ transport mechanism. Using classical molecular dynamics simulations, we find that a vehicular mechanism can be increasingly preferred with a decreasing solvent viscosity and increasing interaction energy between the solvent and Li+. Thus, a weaker interaction energy can enhance tLi through a solvent-exchange mechanism, ultimately improving Li-ion battery performance. Finally, metadynamics simulations show that in electrolytes where a solvent-exchange mechanism is preferable, the energy barrier to changing the coordination environment of Li+ is much lower than in electrolytes where a vehicular mechanism dominates.
Understanding Interfacial Degradation in All Solid-State Lithium Batteries from Multiscale Simulations
Authors: Wan Liwen , Yuan Suyue , Wang Bo , Kim Kwangnam , Heo Tae Wook , Wood Brandon C.
Published: December 2024

All solid-state battery technologies show great promises as next-generation energy storage solutions with opportunities to achieve higher energy density and improved safety features compared to the current liquid-based lithium-ion battery technologies. However, their practicality is limited by high interfacial impedance for ion transport and poor mechanical stability during cycles. In this talk, I will address the key chemo-mechanical coupling effect that critically defines the functionality of interfaces in all solid-state lithium batteries. I will consider the interface of garnet Li7La3Zr2O12 solid-electrolyte and LiCoO2 cathode as an example to demonstrate the powerfulness of multiscale modeling to identify degradation modes that can attribute to high interfacial resistance for Li-ion transport and mechanical failure. Mitigation strategies will be discussed based on manipulation of processing condition and the resulting microstructures to improve interfacial stability and thus enhance the cycling performance of catholyte.

This work was sponsored by the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Next Generation Solid-State Batteries for Electric Aviation
Authors: Dornbusch Donald , Lin Yi , Huddleston William , Yamakov Vesselin I , Viggiano Rocco P.
Published: December 2024

Energy storage will play a critical role in the success of future NASA missions that require batteries with higher energy density, higher power, and most critically improved safety. These performance requirements, which extend beyond those for electric automobile markets, must be satisfied to enable widespread adoption of electric aviation. One approach to improve battery safety and energy is to transition to non-volatile solid-state electrolytes (SSE) which promise many advantages over traditional flammable liquid electrolytes and may also be an enabling technology for next generation chemistries such as lithium-sulfur (Li-S). However, significant manufacturing challenges must be overcome before the adoption of such technology. This study will discuss development of solid electrolytes specifically designed to meet future NASA electric aviation targets. Separator films were processed with densified thickness between 20-30 microns using solvent processing techniques [1]. These films were produced 10-15 times thinner than comparable bulk pressed powder electrolytes and achieved thicknesses comparable to commercial polyolefin separators (25 micron) used in commercial liquid containing lithium-ion cells. Furthermore, design considerations and fabrication techniques of novel cathode composites optimized through the integration of experiment and particle dynamics modeling will be discussed [2] [3].

[1] Donald A. Dornbusch, Rocco P. Viggiano, John W. Connell, Yi Lin, Vadim F. Lvovich. Practical considerations in designing solid state Li-S cells for electric aviation, Electrochimica Acta, 2021, 139406, ISSN 0013-4686,

[2] Vesselin I. Yamakov, April A. Rains, Jin Ho Kang, Lopamudra Das, Rehan Rashid, Ji Su, Rocco P. Viggiano, John W. Connell, Yi Lin. Pressure Dependence of Solid Electrolyte Ionic Conductivity: A Particle Dynamics Study. ACS Applied Materials & Interfaces 2023, 15 (22) , 27243-27252.

[3] Elizabeth A. Barrios, April A. Rains, Yi Lin, Ji Su, John W. Connell, Rocco P. Viggiano, Donald A. Dornbusch, James J. Wu, and Vesselin Yamakov. Li-Ion Permeability of Holey Graphene in Solid State Batteries: A Particle Dynamics Study. ACS Appl. Mater. Interfaces 2022, 14, 18, 21363–21370.
(Invited) Revealing the Reaction Mechanism and Chemo-Mechanics of Solid-State Na-S Batteries
Authors: Nguyen Hung Quoc , Todt Juraj , Boles Steven T , Keckes Jozef , Rettenwander Daniel
Published: December 2024

Solid-state sodium-sulfur batteries show great promise for energy storage applications due to their high energy density, cost-effectiveness, and abundance of raw materials. Despite these promising characteristics, challenges such as the phase evolution of (poly)sulfides and how it is linked to the significant volume expansion occurring in the cathode during cycling are still poorly understood.1,2

In this talk, I will showcase our recent progress in developing solid-state sodium-sulfur batteries using different solid electrolyte systems, namely Na3PS4 and closo-borates. I will discuss how tortuosity impacts sulfur utilization in the composite cathode and provide new insights into sulfur redox chemistry and associated kinetic limitations. Furthermore, I will examine the correlation between phase, volume, and stress evolution.

In summary, this study will offer unprecedented insights into the underlying mechanisms in solid-state sodium-sulfur batteries, which are of utmost importance for their further development towards commercialization.

References

Lei, Y. J., Liu, H. W., Yang, Z., Zhao, L. F., Lai, W. H., Chen, M., ... & Wang, Y. X. (2023). A Review on the Status and Challenges of Cathodes in Room‐Temperature Na‐S Batteries. Advanced Functional Materials, 33(11), 2212600.

Ma, J., Wang, M., Zhang, H., Shang, Z., Fu, L., Zhang, W., ... & Lu, K. (2023). Toward the Advanced Next‐Generation Solid‐State Na‐S Batteries: Progress and Prospects. Advanced Functional Materials, 33(20), 2214430.

Acknowledgment

D.R. acknowledge financial support from the Austrian Federal Ministry for Digital and Economic Affairs, the National Foundation for Research, Technology, and Development, and the Christian Doppler Research Association (Christian Doppler Laboratory for Solid-State Batteries). J.T., J.K., D.R. acknowledge funding from the European Union's Horizon Europe research and innovation program under Grant Agreement No 101103834 (OPERA).
A Computational Approach to Glyme-Based Room Temperature Aluminum Electrodeposition Baths
Authors: Kitada Atsushi , Otsuki Tsubasa , Kanno Tomoya , Takenaka Norio
Published: December 2024

A computational data-driven approach is applied to the design of liquid electrolyte materials. A case study is conducted targeting glyme-based room temperature aluminum (Al) electroplating solutions, where how to achieve higher plating speed has been an open issue. The determination of stable Al-Cl-glyme complex structures by density functional theory (DFT) calculations enables the modeling for molecular dynamics (MD) simulations of the bulk electrolytes, namely aluminum chloride (AlCl3)-diglyme (G2)-cosolvent system. It is shown that a tridentate coordination of diglyme (G2) to [AlCl2]+ is robust against desolvation and one-electron reduction, suggesting that the diffusion coefficients of the [AlCl2]+ cationic complex is an indication of faster plating. Additionally, the calculated diffusion coefficients correlate weakly with the relative permittivity data of cosolvents in their pure state, but strongly with viscosity data. This relationship can be used to design Al plating solutions.

Figure 1
Enhanced Electrochemical Performance of Thin, Flexible Supercapacitors: A Comparative Study of MnO2 Electrodeposition Methods
Authors: Casano Gabriel , Braga Filipe , Caffio Marco , Hardwick Laurence J. , Sanchez Pablo Lozano , Holmes Joanne , Vyas Neil
Published: December 2024

This study presents the fabrication of high-performance, flexible supercapacitors using 3D carbon foam coated with electrochemically deposited MnO2. We investigated galvanostatic and current pulse electrodeposition techniques to optimize MnO2 coatings followed by the evaluation of their impact on charge storage mechanism and electrochemical properties. Results demonstrate that current pulse electrodeposition significantly outperforms galvanostatic deposition, achieving an areal capacitance of 530 mF/cm² under a 10 mA/cm² current rate and exhibiting excellent cycling stability (91% retention after 9000 cycles) and rate capability. Characterization techniques, including cyclic voltammetry, electrochemical impedance spectroscopy, Raman spectroscopy, and SEM, revealed the underlying mechanisms and surface morphology of the MnO2 films, providing valuable insights into the superior performance of current pulse electrodeposition technique. These findings highlight the potential of MnO2-coated 3D carbon foam for high-energy-density, flexible energy storage devices.
Direct Formation of Todorokite Mn Oxide Via Electrodeposition
Authors: Heo Jaeyeong , Jung Haesung
Published: December 2024

Todorokite, a manganese oxide with a 3 × 3 tunnel structure (~1 nm), has attracted interest for its potential application in energy storage, desalination, sensor, and catalyst, owing to its reversible ion exchange capacity and catalytic activity. However, conventional synthesis of todorokite involves a time- and energy consuming three-step process: (1) precipitation of a layered Mn oxide, (2) intercalation of Mg2+ into the layer, and (3) transformation to todorokite via hydrothermal reaction. In this study, we propose a novel method for the direct formation of todorokite within 30 minutes using 1 M MgCl2 electrolyte with Mn2+(aq) at pH 8.5 via electrodeposition. Our electrochemical approach enabled the formation of todorokite by stabilizing structured Mn(III), which induces Jahn-Teller distortion and structural rearrangement to form tunnel, through precise adjustment of pH and concentration of Mg2+. Notably, we confirmed, through computational calculations and experimental results, the significant changes in Mn(III) within Mn oxides approximately pH 7.4, as well as range of Mg(OH)+ concentrations that stabilize Mn(III) for todorokite formation. Our electrochemically mediated method not only facilitates the synthesis of todorokite but also provides specific insights into the mechanisms of its direct formation.
Thermodynamic and Mass Transport Characterization of Lithium Hexafluorophosphate in Dimethyl Carbonate
Authors: Sun Luhan , Wang Andrew A , Monroe Charles W.
Published: December 2024

This research provides a comprehensive analysis of the thermodynamic and transport properties of lithium hexafluorophosphate (LiPF6) in dimethyl carbonate (DMC), which are critical for the performance of lithium-ion batteries. We employed advanced techniques to precisely quantify density fluctuations, which we then systematically correlated with changes in salt concentration and temperature. This intricate relationship was explicated using a data fitting model, conforming to the tenets of Debye–Hückel theory. Through the application of concentrated-solution theory, our study explores the electrolyte's behavior by assessing three key transport properties: cation transference number, ionic conductivity, and thermodynamic diffusivity. This investigation helps elucidate the interactions between different species. Additionally, we describe three thermodynamic characteristics of the electrolyte's equilibrium: the thermodynamic factor, and the partial molar volumes for both the salt and the solvent. The findings offer a detailed insight into the dynamics of the electrolyte, establishing a foundation for improving electrolyte formulations in increasingly complex and concentrated systems.
Photoelectrochemical properties of Single walled and Double walled TiO2 nanotubes
Authors: Lee Ah-yeong , Jung Rin , Yoo JeongEun , Lee Kiyoung
Published: December 2024

Titanium dioxide (TiO2) is one of the most studied materials to be applied in various filed due to its high environmental compatibility and corrosion resistance [1-2]. Among the nanostructures of TiO2 is including nanoparticles, nanorods, nanoplates, and nanotubes, nanotubular TiO2 acquires not only a high surface area but also rapid charge carrier transfer, providing higher efficiency for photocatalytic application such as, the degradation of organic contaminants and hydrogen production. Although various methods have been investigated to fabricate TiO2 nanotubes, the anodization technique is favored with its straightforward control over structure and direct growth on Ti substrates[3]. However, conventional anodic TiO2 nanotubes exhibit surface irregularities and double-walled structure consisting of carbon-rich inner and TiO2 out layer[4]. The inner layer of TiO2 nanotubes diminishes the photoelectrochemical efficiency owing to the carbon contamination.

In this study, double walled TiO2 nanotubes were synthesized by anodization with an applied voltage of 60 V for various periods. A piranha solution was utilized to eliminate the inner layer for double walled TiO2 nanotubes, achieving a single-walled TiO2 nanotube configuration. The morphological properties, crystallinity, and surface resistance of both single and double-walled TiO2 nanotubes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Electrochemical Impedance Spectroscopy (EIS). In addition, the photoelectrochemical efficiencies of all TiO2 nanotubes were evaluated employing linear sweep voltammetry (LSV) and Incident photon-to-current efficiency (IPCE) measurements. As a result, the single-walled TiO2 nanotubes, produced under the specific conditions of 60 V for 7 min, showed the highest photoelectrochemical efficiencies at LSV and IPCE. The higher photoelectrochemical properties of the single walled nanotube are attributed to the enhancenment of surfave chage dynamics and environmental reactions as eliminating the inner layer.

[1] Fujishima A, Honda K, Electrochemical photolysis of water at semiconductor electrode. Nature 238 (1972) 37-38

[2]Lee K, Mazare A, Schmuki P, One-dimensional titanium dioxide nanomaterials: nanotubes, Chem. Rev, 114 (2014) 9385–9454,

[3] Yoo JE, Lee K, Altomare M, Selli E, Schmuki P, Self-organized arrays of single-metal catalyst particles in TiO2 cavities: a highly efficient photocatalytic system, Angew. Chem., Int. Ed, 52 (2013) 1002

[4] Liu N, Mirabolghasemia H, Lee K, Albua SP, Tighineanua A, Altomareab M, Schmuki P, Anodic TiO2 nanotubes: double walled vs. single walled. Faraday Discuss, 164 (2013) 107-116.
Physical and Electrochemical Properties of Zinc Chloride and Potassium Chloride Based Non-Aqueous Electrolytes
Authors: Mishra Arpita , P Manju , Sarkar Arindam , Suthar BharatKumar
Published: December 2024

Ethylene glycol is a useful solvent which has applications in thermal, electrochemical and chemical systems as an antifreeze, dehydrating agent and corrosion preventor. Here, we have focused on some physical and electrochemical properties of the solvent which might help in determining a good performing electrolyte in a battery. We have added zinc chloride (ZnCl2) and potassium chloride (KCl) in ethylene glycol and made a ternary diagram of the three compounds according to which we have varied the concentrations of both salts. The mixtures were prepared in a glove box to not absorb moisture from the environment due to humidity. The electrochemical characterization of the solutions was done in zinc-zinc symmetric coin cells on which electrochemical impedance spectroscopy was performed at room temperature. This enabled the determination of the electrolyte resistance, exchange current density and activation energy. Additionally, ionic conductivity and viscosity were also measured using a conductivity meter and rheometer.

We observed that as ZnCl2 and KCl increased, conductivity increased, and it was maximum where both the salt concentrations were maximum. However, the exchange current density reached its maximum somewhere in the middle after which increasing the concentration resulted in its decrease. Viscosity increased slowly as the amount of ethylene glycol decreased and then it rose up steeply for the solution where no KCl was present and zinc chloride was maximum. These results showed a pattern of how the parameters depend on each species' concentration. The data trends were tried to be fitted by an equation model to predict its behavior at any arbitrary concentration. The conductivities of some concentrations were comparable to LiPF6 which is a common electrolyte used in lithium-ion batteries.

The findings contribute to understanding the solution’s performance in zinc or potassium ion batteries or capacitors as an electrolyte. These results can also be used for studying the electroplating attributes of zinc.
Advancements in Redox-Mediated Electrodialysis for Valorization of Biomolecules
Authors: Kim Nayeong , Aguda Aderiyike , Lee Jiho , Jeon Jemin , Elbert Johannes , Su Xiao
Published: December 2024

In the chemical and biochemical manufacturing industry, separation processes are amongst the most energy-demanding processes, accounting for 50% of total operating costs.1, 2 Redox-mediated electrodialysis (redox-ED) has attracted attention as a process-intensified method for resource recovery, particularly selective recovery of organic molecules such as proteins and organic acids.2, 3 By replacing water-splitting reactions with reversible redox reactions, pH-sensitive biomolecules can be electrochemically recovered with reduced overall energy consumption. We demonstrated the valorization of proteins from whey waste via the redox-ED platform.2 Our system treated 99% of salt from the whey solution within a single step and recovered over 98% of various whey proteins (e.g., beta-lactoglobulin and alpha-lactalbumin). The preliminary techno-economic analysis confirmed the economic viability of redox-ED with 51−73% lower energy consumption compared to conventional ED.

Moreover, we mitigated the inherent limitation selectivity of ion-exchange membranes in discriminating among the same charged species (e.g., cations and anions), by employing a layer-by-layer (LBL) membrane functionalization approach.3 This LBL membrane modification enabled the recovery of organic acids from a multicomponent mixture, where there is a mixture of neutral and charged species. By tailoring the physicochemical properties of IEMs through the LBL polyelectrolyte layers, we achieved complete retention of succinic acid produced in the fermentation process, while enhancing the overall flux for inorganic ions.3 Redox-ED with LBL-functionalized membrane demonstrated the continuous up-concentration of succinate alongside the isolation of unreacted sugar and inorganic ions, opening avenues for modular multicomponent separations in biomanufacturing processes.

References

(1) Kim, N.; Jeon, J.; Chen, R.; Su, X. Electrochemical separation of organic acids and proteins for food and biomanufacturing. Chemical Engineering Research and Design
2022, 178, 267-288.

(2) Kim, N.; Jeon, J.; Elbert, J.; Kim, C.; Su, X. Redox-mediated electrochemical desalination for waste valorization in dairy production. Chemical Engineering Journal
2022, 428, 131082.

(3) Kim, N.; Lee, J.; Su, X. Precision Tuning of Highly Selective Polyelectrolyte Membranes for Redox‐Mediated Electrochemical Separation of Organic Acids. Advanced Functional Materials
2023, 33 (12), 2211645.
Model-Based Development of Control Strategies for a Fuel Cell Air Supply System and Experimental Verification at Flight-Relevant Conditions
Authors: Frank Daniel , Wazlawik Stefan , Brandao de Almeida Samara , Bauer Christiane , Willich Caroline
Published: December 2024

The performance of hydrogen PEM fuel cell systems can be optimized by means of pressurization of the cathode air, especially in aviation, where at in-flight conditions the pressure of the ambient air is significantly lower as at on-ground conditions. To provide the inlet air at optimal conditions (p, T, rH) during flight, an air supply system is required and in an all-electric aircraft the compression should happen by means of an electric centrifugal compressor. A challenge for the operation of a pressurised fuel cell system at high altitudes is the control of the compression system. Any unstable operation like compressor surge has to be avoided, since it can damage both the fuel cell stack and the compressor itself. For the development of such an air supply system, a combined experimental and modeling approach was chosen.

A hydrogen PEM fuel cell system was characterized at nominal and at low cathode pressures to obtain the behavior at flight relevant conditions and an experimental air supply system containing electric compressor, intercooler, humidifier, cathode volume and throttle valve at the outlet has been set up and used for the development, parameterization, and validation of a model for the compression system. The model is based on the Greitzer model 1,2, and has been extended to also represent the additional components between the compressor and the throttle valve (intercooler, humidifier, and cathode volume) 3. It is now able to predict the transient response of the entire air supply system to changes in the reference values of compressor speed and valve opening angle and the resulting mass flow changes and pressures within the individual components.

The model and the data from the fuel cell system were used for the development of improved control strategies, that make it possible to operate the system safely in a wide range of operating conditions. Unstable situations, like compressor surge, are avoided by these control strategies even in the highly varying conditions during a flight. The developed control strategies are verified on the hardware of the experimental setup and tested under realistic flight conditions in a low-pressure climate chamber.

References

Greitzer, E. M. Surge and Rotating Stall in Axial Flow Compressors—Part I: Theoretical Compression System Model. Journal of Engineering for Power
98, 190–198 (1976).

Gravdahl, J. T. & Egeland, O. Compressor Surge and Rotating Stall. (Springer London, London, 1999). doi:10.1007/978-1-4471-0827-6.

Frank, D., Bauer, C. & Willich, C. Modeling of the cathode air supply for a pressurized hydrogen fuel cell system in airborne applications. Proceedings of the Aerospace Europe Conference 2023 (2023) doi:10.13009/EUCASS2023-218.
(Invited) Reduced Order Modeling of Li-Ion Battery Systems - from Fundaments to Real-Life Applications
Authors: Coman Paul , White Ralph E.
Published: December 2024

The development of efficient and safe battery packs is crucial for advancing energy storage technologies. This presentation offers a comprehensive overview of the transition from full-order physics-based modeling to reduced order modeling (ROM) in the context of single battery cells and battery packs, with a specific emphasis on managing and understanding thermal runaway. A detailed exploration of the methodologies used in full-order physics-based models, including ROM and multiphysics coupling, will provide a granular view of electrochemical, thermal, and electrical behaviors in battery systems.

To address these challenges, the presentation explores the development and application of reduced order models that approximate the behavior of these complex systems with significantly reduced computational demands. The focus is on simplifying the models while retaining essential dynamics, particularly in the context of thermal management to prevent thermal runaway.

The session will also cover how ROMs can accurately predict temperature and voltage within battery packs, enhancing predictive capabilities and operational safety. The electrical modeling of bus-plates and the electromagnetic modeling of cylindrical single cells will be discussed, highlighting their importance in the overall performance and safety of battery systems.

The discussion extends to the application of these ROMs in real-world scenarios, illustrating how they can be integrated into battery management systems to enhance performance and safety while ensuring efficiency. Case studies where ROMs have been successfully implemented to predict and mitigate thermal runaway in battery packs will be highlighted, showcasing the transition from fundamental research to practical applications.
Quantifying Volume Change in Porous Electrodes Via the Multi-Species, Multi-Reaction Model
Authors: Garrick Taylor R. , Fernandez Miguel , Verbrugge Mark , Labaza Christine , Mollah Rafid , Koch Brian , Jones Matthew , Gao Jing , Gao Xiujie , Irish Nicholas
Published: December 2024

Automotive manufacturers are working to improve individual cell and overall pack design by increasing their performance, durability, and range, while reducing cost; and active material volume change1–7 is one of the more complex aspects that needs to be considered during this process. As the time from initial design to manufacture of electric vehicles is decreased, design work that used to rely solely on testing needs to be supplemented or replaced by virtual methods. As electrochemical engineers drive battery and system design using model-based methods8, the need for coupled electrochemical/mechanical9 models that take into account the active material change utilizing physics based or semi-empirical approaches is necessary. In this study, we illustrated the applicability of a mechano-electrochemical coupled modeling method considering the multi-species, multi-reaction model as popularized by Verbrugge10,11 and Baker. To do this, validation tests were conducted using a computer-controlled press apparatus that can control the press displacement and press force with precision. The coupled MSMR volume change model was developed and its applicability to graphite and NMC cells was illustrated. The increased accuracy of the model considering the coupled MSMR volume change approach shows in the importance of accounting for individual gallery volume change behavior on cell level predictions.

References:

T. R. Garrick et al., J. Electrochem. Soc., 164, E3592 (2017).

T. R. Garrick, X. Huang, V. Srinivasan, and J. W. Weidner, J. Electrochem. Soc., 164, E3552 (2017).

T. R. Garrick, K. Kanneganti, X. Huang, and J. W. Weidner, J. Electrochem. Soc., 161, E3297 (2014).

T. R. Garrick et al., J. Electrochem. Soc., 170, 060548 (2023).

D. J. Pereira, A. M. Aleman, J. W. Weidner, and T. R. Garrick, J. Electrochem. Soc., 169, 020577 (2022).

D. J. Pereira et al., J. Electrochem. Soc., 167, 080515 (2020).

D. J. Pereira, J. W. Weidner, and T. R. Garrick, J. Electrochem. Soc., 166, A1251 (2019).

T. R. Garrick, Y. Zeng, J. B. Siegel, and V. R. Subramanian, J. Electrochem. Soc., 170, 113502 (2023).

S. Pannala, H. Movahedi, T. R. Garrick, A. G. Stefanopoulou, and J. B. Siegel, J. Electrochem. Soc., 171, 010532 (2024).

M. Verbrugge, D. Baker, B. Koch, X. Xiao, and W. Gu, J. Electrochem. Soc., 164, E3243 (2017).

M. Verbrugge, D. Baker, and X. Xiao, J. Electrochem. Soc., 163, A262 (2015).
Inductive Behavior in Electrochemical Impedance Spectroscopy: Can We Discriminate between Adsorption and Non-Stationarity
Authors: Benbouzid Abdelmoheiman Zakaria , Turmine Mireille , Vivier Vincent
Published: December 2024

Electrochemical impedance spectroscopy (EIS) is a widely used technique for studying electrochemical processes. EIS typically assumes a linear relationship between the applied signal (potential or current) and the measured response (current or potential). In other words, doubling the input perturbation must result in doubling the output, and the output signal must show no change in shape. However, by using “small input signals”, a linear response can be achieved. Similarly, stationarity is also a requirement for EIS measurements. In this case, several factors may be at the origin of the problem. For instance, as an electrochemical reaction progresses, the electrode surface and the surrounding electrolyte can change, affecting the resistance and capacitance, and consequently, the impedance. Temperature variations can also affect the conductivity and mobility of ions, leading to a shift in impedance as a function of the frequency. If a system is non-stationary during an impedance measurement, the measured value won't represent a single, fixed state. The impedance will depend on the time the measurement was taken. This can make it difficult to interpret the data and compare it with other measurements.

Conversely, reaction mechanism involving adsorbates may be misinterpreted. Indeed, adsorption processes can result in either capacitive or inductive time-constants, usually observed in the low frequency domain. Such a behavior has been reported in the literature for corrosion processes. In this presentation, we will show how non-stationarity can modify an impedance diagram. Particular attention will then be paid to the case of the response of an adsorbed intermediate, such as the corrosion of Mg, for which inductive feature can be observed. The importance of the Kramers-Kronig relationships will then be discussed.
Efficient Electrochemical Conversion of Ammonium Nitrate Solutions Using Novel Electrodes
Authors: Alvarez Pugliese Christian E , Haque Alamgir Mojibul , Ogonna Okoye Francis , Azuka Kingsley , Gutierrez-Carballo Alejandro , Babar Pravin , Botte Gerardine G
Published: December 2024

ANSOL, a byproduct of the production of energetic materials, is a chemical waste composed mainly of ammonium nitrate. In this study, we investigate various electrochemical methods for converting ANSOL into hydrogen, nitrogen, and/or ammonia (Figure 1). To our knowledge, this is the first comprehensive examination in the literature of the electrocatalytic conversion of ≥ 1M ammonium nitrate solutions in alkaline media using Ni, Cu, Co, Pt, Ir, and combinations thereof. We employ different electrode synthesis techniques, including electrodeposition, nanoparticle synthesis via polyol methods, and thermal reduction.

Our approach is based in Botte's patented Ammonia GreenBox technology [1-3], which has demonstrated the conversion of ammonia into hydrogen and nitrogen at pilot scale in wastewater treatment, and most recently on the simultaneous removal of nitrates and ammonia [4]. Our findings reveal remarkable activity and selectivity in the electrochemical nitrate reduction and ammonia oxidation reactions, resulting in high ammonia and hydrogen yields with exceptional Faradaic efficiencies.

Figure 1
Bipolar Hydrogen Production from Electrocatalytic Oxidative Dehydrogenation of Biorenewable Furfural in Membrane-Less Electrolyzers
Authors: Li Wenzhen , Liu Hengzhou , Chen Yifu , Agrawal Naveen , Janik Michael
Published: December 2024

Water electrolysis has been considered a green process for hydrogen production. Conventional electrolysis is limited by the sluggish anodic oxygen evolution reaction (OER), leading to high energy input. In addition, the temporal spatial coupling of the production of H2 and O2 can cause issues associated with safety, economic feasibility, and system flexibility. Herein, we reported our work on replacing OER with an electrocatalytic oxidative dehydrogenation (EOD) of biomass-derived furfural for bipolar H2 production (from both cathode and anode) at low electrolytic cell voltages and high current densities. Experimental and DFT studies suggested a reasonable barrier for C-H dissociation on Cu surface, mainly through the diol intermediate, with the potential-dependent competition with Cannizzaro reaction. We revealed that EOD on metallic Cu surface was linked to an autocatalytic Cu oxides reduction by aldehydes along with H2 evolution. The EOD kinetics and durability was further enhanced by a porous CuAg catalyst prepared by a galvanic replacement method. We engineered a bipolar H2 production system using membrane-electrode assembly-based flow cells to facilitate mass transport, achieving a combined faradaic efficiency (FE) of ~200% to H2 and the maximum H2 partial current density of 248 and 390 mA/cm2 at cell voltages of 0.4 V and 0.6 V, respectively. We further studied other CuM (M= Pt, Pd, Au) bimetallic catalysts for EOD reaction, and found that dispersing Pt into Cu (CuPt) exhibited a unique synergistic effect for furfural EOD possibly via efficient C-H cleavage on Cu and favorable furfural binding on Pt. The CuPt anode-based flow electrolyzer has achieved a higher current density of 498 mA/cm2 at a low cell voltage of 0.6 V and FE of >80% to H2. Inexpensive dialysis membranes and non-noble metal HER catalysts are possibly used for bipolar H2 production, which provides an alternative approach for distributed manufacturing of green hydrogen and carbon chemicals in the future.
Investigating Characteristics of Anion Exchange Membranes Utilizing Various Anion-Conducting Monomers for Water Electrolysis
Authors: Jeong Dahye , Lee Minyoung , Park Yeri , Akter Mahamuda , Park Jong-Hyeok , Park Jin Soo
Published: December 2024

Water electrolysis, a sustainable technology, converts electrical energy into chemical energy, producing hydrogen as a clean energy source and fuel. While both proton exchange membrane and anion exchange membrane water electrolysis (AEMWE) exist, the widespread adoption of AEMWE faces challenges due to the low ionic conductivity and chemical/mechanical instability of anion exchange membranes (AEMs). To overcome these hurdles and increase market penetration, there's a need to develop AEMs with low resistance and high durability, necessitating comprehensive research on the entire polymer structure. In this study, we focused on preparing various AEMs and analyzing their properties. We employed different anion-conducting monomers to create highly conductive and chemically/mechanically stable pore-filling AEMs for AEMWE. These pore-filling AEMs were fabricated by infusing and crosslinking anion-conducting monomers within a porous polyethylene substrate. We characterized these membranes in terms of areal resistance, ionic conductivity, ion exchange capacity, contact angle, water uptake, swelling ratio, mechanical strength, and hydrogen crossover. Additionally, we conducted performance and durability tests for AEMWE and discussed the findings.

Acknowledgments

This research was supported in part by Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ016253), Rural Development Administration, Republic of Korea and by 2021 Green Convergence Professional Manpower Training Program of the Korea Environmental Industry and Technology Institute funded by the Ministry of Environment.
(Invited) ALD HfZrO2 Films from Ferroelectric to High-k Applications
Authors: Leonhardt Alessandra , Cimada Jessica , Ramachandran Ranjith , Surman Matthew , John Rohit , Mootheri Vivek koladi , Tang Fu , Schmotzer Michael , Givens Michael , Balseanu Mihaela , Illiberi Andrea
Published: December 2024

HfO2 based ferroelectric (FE) materials have gained tremendous attention as a potential candidate for memory applications such as FeFET and FeRAM. Since its first demonstration as a FE material [1],

immense research has been done to circumvent the challenges such as scalability, increasing the

remnant polarization (Pr), and improving endurance. Among others, Zr-doped HfO2, HfZrO2 (HZO) is being intensively studied due to its compatibility with complementary metal oxide semiconductor (CMOS) processing and excellent scalability. ALD has been the technique of choice for the deposition of those films, due to the high conformality, high film quality and simplicity of tuning the composition. HZO has excelled in this field, with high polarization, high endurance and retention. Those properties were still further improved by the addition of dopants such as La, which resulted in the record high 2Pr for films fabricated by ASM and imec using metalorganic precursors [2].

In this presentation we take ALD HZO one step forward, and describe how, by tunning the processing parameters of these films , the ferroelectricity can be modulated in a broad range, and how this can be incorporated in applications where high dielectric constants are desired. We discuss significant learnings in this material system regarding phase composition and crystallization dynamics, and how these can be used to modulate HZO from a ferroelectric into a high-k material. The extreme adaptability of ALD HfZrO2 provides an opportunity for its insertion in different applications. This material can extend logic and memory roadmaps, providing high capacitance, low leakage and high 2Pr, all at ultra-scaled thicknesses.

References

S. Boscke et al, Appl. Phys. Lett. 99, 102903 (2011)

I. Popovici and J. Bizindavyi et al, IEDM 2022
ALD Synthesis of Transition Metal Phosphides
Authors: Zazpe Raul , Rodriguez Pereira Jhonatan , Charvot Jaroslav , Klikar Milan , Bures Filip , Macak Jan M.
Published: December 2024

The ever-increasing global energy demand together with the environmental issue originated from the use of fossil fuel, has triggered an intense search for sustainable and clean energy alternatives, such us hydrogen energy, biomass and solar energy among others. In this context, a pivotal key to deliver sustainable and superior energy systems lies on the rational design and development of high-quality and cost-effective catalyst offering enhanced stability, activity and selectivity. Consequently, intense efforts have been devoted in the search and synthesis of new catalyst materials to replace the scarce and expensive traditional noble metals (e.g. Pt, Pd, Au and Ru) for energy conversion and energy storage applications.

Among the recently explored novel catalyst materials, metal phosphides (MPs) have emerged in recent years, attracting significant attention thanks to their intriguing properties [1]. In particular transition metal phosphides (TMPs) exhibit striking properties. The moderately strong M−P bonds lend outstanding mechanical properties, high thermal stability and outstanding chemical resistance to chemical attack and oxidation in acidic and alkaline solutions. Additionally, Co, Ni, Mo-based phosphides demonstrated excellent catalytic and bifunctional properties, in particular towards water splitting as both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) [2,3].

Herein, we present the synthesis of TMPs by thermal Atomic Layer Deposition (ALD) based on the use of different transition metal precursors and tris(trimethylsilyl)phosphine. The physical and chemical properties of the resulting TMPs thin films were extensively characterized by different methods, including atomic force microscopy, X-ray photoelectron spectroscopy and X-Ray diffraction. The presentation will introduce and describe the synthesis of the TMPs and the corresponding physical and electrochemical characterization toward electrocatalytic application.

[1] Z. Pu, T. Liu, I. S. Amiinu, R. Cheng, P. Wang, C. Zhang, P. Ji, W. Hu, J. Liu, S. Mu, Transition-metal phosphides: activity origin, energy–related electrocatalysis applications, and synthetic strategies, Adv. Funct. Mater., 2020, 30, 2004009.

[2] C.C. Weng, J.T. Ren, Z.Y. Yuan, Transition Metal Phosphide-Based Materials for Efficient Electrochemical Hydrogen Evolution: A Critical Review, ChemSusChem, 2020, 13, 3357-3375.

[3] C.-J. Huang, H.-M. Xu, T.-Y. Shuai, Q.-N. Zhan, Z.-J. Zhang, G.-R. Li, A review of modulation strategies for improving catalytic performance of transition metal phosphides for oxygen evolution reaction, Applied Catalysis B: Environmental, 2023, 325, 122313.
Ir-ALD Incorporated 2D Mxene Advanced Heterostructures for Green Hydrogen Energy Applications
Authors: Mohapatra Debananda , Son Yeseul , Park Chaehyun , Kweon Minjeong , Kim Soo-Hyun
Published: December 2024

Noble metals such as Pt, Ir, Ru, Pd, and Rh are also known as the precious platinum group of elements, demonstrating outstanding thermal, electrical, and electrochemical properties via excellent catalytic activities. However, they are costly and rare, mainly iridium (Ir), whose natural abundance is approximately one-tenth of the Pt and Ru precious metals. Ir is considered one of the best catalytic electrode materials after Pt, with high thermal stability, corrosion resistance, and low resistivity. Notably, for green hydrogen fuel economy, the high cost and intelligent, precise use of those precious metals remain challenging. Atomic layer deposition (ALD) is an emerging industrially recommended atomic-level control technique to deposit the rarest noble metals as single metal atoms or clusters through their self-limiting growth and precision. For the first time, we introduced the practical use of Ir precious metals sensibly and smartly through ALD on emerging 2D V-MXene in its single atomic/cluster form by forming advanced Ir-ALD-V-MXene heterostructure, considering its cost and rarity for the next-generation hydrogen fuel application. Incorporating Ir-ALD into 2D V-MXene eliminated the stacking and dead volumes, which are significant challenges in 2D nanomaterials for hydrogen evolution catalysts, strategically altering the overall electronic and electrochemical properties. Remarkably, Ir single atoms/clusters empower the surface catalytic activity; hence, considering its scarcity, the enhanced catalytic performance per Ir atom with significantly less use of the Ir precious metals compressively investigated by computational and next-generation aberration corrected ultra-high-resolution advanced electron microcopies. Ir-ALD incorporated V-MXene demonstrated exceptionally 260% higher electrocatalytic activities than that of pristine V-MXene just by smartly controlling the Ir-ALD cycle numbers, hence reducing the use of precious metals. This study paves a vital approach through an emerging ALD process technique for creating new precious metal-based electrocatalysts on ever-expanding MXene 2D nanomaterials for clean energy conversion and storage devices.
Controlling Electronic and Ionic Conductivity in oMLD Polymer Coatings
Authors: Young Matthias J. , Paranamana Nikhila C , Mehregan Mahya , Mehregan Shima , Datta Amit
Published: December 2024

Thin film polymer coatings formed by oxidative molecular layer deposition (oMLD) are of interest as ion-selective membranes for electrochemical sensors, and as protective coatings for lithium ion batteries. In both of these applications, it is critical to control the electronic conductivity, the ionic conductivity, and the ion selectivity of the MLD coatings. Recent understanding of the oMLD mechanism reveals this synthesis method as a path to control the molecular sequence of conjugated heteroatom-containing copolymers. We employ oMLD to reveal fundamental insights into how the molecular sequence of these copolymers influences conductivity, shifting the electronic conductivity by more than three orders of magnitude by altering the molecular sequence. We also summarize the development of new oMLD chemistries including polythiourea (PTU), polyhydroquinone (PHQ), and poly(2,5‐Dimercapto‐1,3,4‐Thiadiazole) (PDMCT). We employ in-situ quartz crystal microbalance (QCM) studies during oMLD growth to understand the chemical growth mechanisms, as well as ex-situ spectroscopic ellipsometry (SE), electrical impedance spectroscopy (EIS), and electrical Van der Pauw measurements, and electrochemical characterization to identify material properties. We examine PTU as an anion-selective membrane for ion sensor applications, and PHQ and PDMCT as protective coatings for lithium-ion battery applications that provide enhanced Li+-ion conductivity with control over electronic conductivity.
(Invited) Enhancing the Performance of Lithium-Ion Cathodes
Authors: Croy Jason R. , Chen Jiajun , Mallick Subhadip , Pathak Rajesh , Elam Jeffrey W.
Published: December 2024

Significant attention has recently been given to increasing the energy density of commercial LiNi1-x-yMnxCoyO2 (NMC) lithium-ion cathodes with an added constraint of greatly mitigating the use of cobalt. These two goals can be achieved in a seemingly straightforward manner by simply increasing Ni contents, and several Ni-rich compositions have found commercial success. Nonetheless, the increasing demand for lithium-ion batteries has brought about the realization that a more diverse portfolio, with respect to cathode materials, will be critical to ensure supply chain security, lower costs, and wide-spread adoption of energy storage technologies. More specifically, substantially increasing the use of earth-abundant materials is now viewed as a necessary path forward to ensure sustainability. Earth-abundant elements are attractive options in terms of sustainable technological development as they have the potential for positive impact with respect to increasing the availability of raw materials, ultimately lowering costs, and increasing accessibility of dependent technologies such as electric vehicles.

Regardless of the class of cathode under consideration for a given application, a common theme among all lithium-ion cathode materials is their need for modification in order to meet the stringent demands of application. Of note, all cathode materials generally require surface stabilization to help enable acceptable performance in terms of metrics such as cycle-life and impedance. This is particularly true in the drive to develop solid-state batteries. In addition, small compositional changes in the way of bulk and surface dopants can also have a major impact on long-term performance.

This presentation will discuss work ongoing at Argonne National Laboratory related to the modification of lithium-ion cathodes. Commercially relevant materials, as well as novel materials currently in development at Argonne, will be explored. Atomic layer deposition will be highlighted as a unique tool to not only enable enhanced battery cell performance, but also as an opportunity to discover new materials in the rapidly expanding market of lithium batteries.