bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethylene Carbonate Oxidation Due to Reactive Oxygen Species Near the Cathode: Insights from High-Throughput DFT Calculations and Monte Carlo Simulations
Authors: Mohanakrishnan Rohith Srinivaas , Vijay Sudarshan , Spotte-Smith Evan Walter Clark , Rinkel Bernardine L. D. , McCloskey Bryan D. , Persson Kristin A.
Published: December 2024

Understanding the intricate pathways of ethylene carbonate (EC) decomposition is pivotal for enhancing the stability and efficiency of electrolytes in various electrochemical applications. In this study, we delve into the decomposition mechanisms of EC in the presence of superoxide and peroxide species. The decomposition of EC-based electrolytes causes gas (carbon dioxide, carbon monoxide and hydrogen) evolution. Since this gas evolution is observed at potentials much lower than the oxidation potential of EC, it has been suggested that the mechanisms leading to decomposition are primarily chemical in nature (i.e., not related to the electrochemical oxidation of EC) and related to the reaction of reactive oxygen [singlet, superoxide, peroxide] with EC. [1,2,3]. Utilizing high-throughput Density Functional Theory (DFT) calculations, we meticulously explored the reaction networks of EC with superoxide and peroxide species across different cathode voltages. Our findings unveil compelling insights into the primary pathways dictating EC decomposition, which notably occur at potentials significantly lower than the oxidation potential of EC. Monte Carlo simulations were performed to understand the major products of the reaction network. Carbon dioxide is one of the major products in the reaction networks. Other major products include mono-carbonate, formaldehyde and organic products containing O-O in the fragments. We find that the products with O-O bond in the organic chain were also previously observed through mass spectroscopy experiments in [4]. Thus, using high-throughput data-driven approach, we are able to identify novel decomposition pathways of ethylene carbonate near the cathode.

Reference

[1] Freiberg, Anna TS, et al. “Singlet oxygen reactivity with carbonate solvents used for Li-ion

battery electrolytes.” The Journal of Physical Chemistry A 122.45 (2018): 8828-8839.

[2] Wandt, Johannes, et al. “Singlet oxygen evolution from layered transition metal oxide

cathode materials and its implications for lithium-ion batteries.” Materials Today 21.8 (2018):

825-833.

[3] Rinkel, Bernardine LD, et al. “Electrolyte oxidation pathways in lithium-ion

batteries.” Journal of the American Chemical Society 142.35 (2020): 15058-15074.

[4] Kaufman, et al. “Surface Lithium Carbonate Influences Electrolyte Degradation via Reactive Oxygen Attack in Lithium-Excess Cathode Materials” Journal of the American Chemical Society (2021): 4170–4176
Architecture Design of High-Performance Electrodes Guided by Large-Scale, High-Throughput Microstructure Simulations
Authors: Malik Affan , Snyder Kent , Liu Minghong , Yu Hui-Chia
Published: December 2024

A battery’s actual operational performance is dictated by electrode microstructure architectures besides electrode materials’ intrinsic properties. However, because of the complexities of coupled physics and microstructures, most electrode designs proceed by a traditional trial-and-error fashion. In this work, we employ a direct image-based multiphysics electrochemical simulation framework to perform detailed microstructure-level simulations in an unprecedented speed. Yet the results still contain all the details of multiphysics dynamics in the explicitly considered complex microstructure geometries. We use graphite electrodes to demonstrate these high-throughout-style microstructure simulations with the phase field approach to precisely model the phase transitions in individual graphite particles during lithiation/delithiation. Autonomous simulations were performed on series of automatically modified graphite electrode microstructures to extract the optimal design that enhances high-rate performance of thick electrodes. This presented simulation tool will greatly facilitate battery developers to identify electrode design to meet specific operation needs.
Multi-Model Architecture for Achieving Extended Battery Life Predictions
Authors: Gering Kevin L. , Savargaonkar Mayuresh
Published: December 2024

Artificial Intelligence tools such as Machine Learning (ML) will no doubt revolutionize how the battery community approaches many facets of battery research and management. This is particularly true in the area of battery life predictions over periods of time relevant to long-term applications (say, 10-20 years). Yet, with the emergence of ML tools, there is an abiding need to maintain a presence of physics-based “truth” that can guide ML practitioners toward realistic outcomes. This work covers a multi-model architecture that employs a combination of data-driven and materials-driven components that, when in tandem, provide a highly effective framework for achieving life predictions well past the end of test data. Data-driven techniques involve physics-guided deep learning and Bayesian methods, while a materials-driven model predicts fundamental degradation pathways based on materials interactions at the conditions of use, enabling generation of key synthetic data. Results will be presented for various Li-ion cell chemistries (NMC/Gr, LTO/LMO, others), wherein contributions from foremost degradation mechanisms will be identified (loss of lithium inventory, LLI, and loss of active material, LAM). With this we obtain electrode-specific LLI and LAM diagnostics as well as long-term aging predictions that can span several years. The functionality of this multi-model architecture supports materials selection, electrode design, diagnostic aging evaluations, as well as appraisal and optimization of duty cycle conditions to minimize aging trends of the chosen battery chemistry.
(Invited) TFT Technologies from Commercial Displays to Emerging Immersive Displays
Authors: Kuo Yue , Nathan Arokia
Published: December 2024

Thin film transistors (TFTs) are used in displays providing the function of controlling light transmission, such as LCDs, reflection, such as electrophoretic displays, or emission, such as LED or OLED displays, from individual pixels in a 2D array – named active matrix flat panel displays (AMFPDs). The advantages of using TFTs in displays include gray-scale, dynamic, crosstalk-free, and uniform images as well as low power consumption over a large area.

The first report on the functional TFT and the outline and demonstration of the TFT LCD triggered worldwide research and development activities on AMFPDs. The lack of commercial products on the market is due to the bottleneck in the manufacturing technology, i.e., availability of a large area, low temperature, and high throughput process. The invention of the a-Si: H TFT in 1979 solved the production problem [1]. TFT LCDs were quickly introduced to the market. The size of the commercial displays changed from 4” in the 1980s to 98” in 2023, as shown in Figure 1 [2]. Extremely low power consumption electrophoretic displays were also introduced to the market. The main drawback of the a-Si:H TFT is the low field effect mobility, e.g., £1 cm2/Vs, which limits applications in driver circuits as well as very high speed or high driving current displays. Poly-Si TFTs can have mobilities up to 2 orders of magnitude higher than that of a-Si:H TFT. However, due to the complicated process conditions, their applications have been limited to small-sized displays, such as 20-inch LCDs, OLEDs, and μ-LEDs. The driver circuits were successfully integrated into the display. The a-IGZO TFT has a field effect mobility between those of a-Si:H TFT and poly-Si TFT. The a-IGZO TFT array can be mass-produced at a low temperature on a large substrate. Therefore, since the first report of the a-IGZO TFT in 2004 [3], it was quickly accepted by the display industry. Commercial OLEDs and μ-LEDs based on a-IGZO TFTs have been manufactured. Driver circuits have also been demonstrated. However, due to the lack of the p-channel TFT, the CMOS circuit has to be made of the n-channel oxide TFT and the p-channel poly-Si TFT.

Recently, due to the advancement in semiconductor technology and software, immersive displays have emerged in areas of entertainment, industry, education, etc. Displays play an important role in this trend because the human interface with the data is critical to these functions [4]. There are some basic requirements on the display concerning image quality, power consumption, response to the environment, and the user’s physical condition. In many applications, the size, weight, and flexibility of the display are important. In this paper, the authors will discuss these issues based on the existing TFT technology and explore opportunities.

Kuo, ECS Interface, 22(1), 55-61, 2013.

A commercial TCL 98" LCD downloaded from Google.

Nomura, et al., Nature, 432, 488-492, 2004.

Kuo, IEEE J. Immersive Displays, 1, 28-40, 2024.

Figure 1
(Invited) Irreproducibility of High-Performance Perovskite Solar Cells: Causes and Solutions
Authors: Lee Jin-Wook
Published: December 2024

Metal halide perovskite solar cells (PSCs) have been spotlighted as a promising next-generation photovoltaic technology. Recently, there has been a surge of efforts in the commercialization of PSCs in academia and industries worldwide with record power conversion efficiencies over 26% for both n-i-p and p-i-n structured devices. Nevertheless, their subpar operational durability, module scalability, and material toxicity are challenges often brought up as the major barriers hindering practical commercialization. The poor reproducibility of PSCs has been relatively overlooked, but negatively impacts institutional research laboratories, start-up companies, and large established corporations all alike. Reproducible fabrication of PSCs is a critical consideration for market viability and practical commercialization. In this work, I will discuss the critical functions of atmospheric humidity to regulate the crystallization and stabilization of formamidinium lead triiodide (FAPbI3) perovskites. We demonstrate that the humidity content during processing underlies profound variations in perovskite stoichiometry, thermodynamic stability, optoelectronic quality and thus reproducibility of PSCs. In second part of the presentation, I will discuss the interplay between composition of perovskite, and performance, stability and reproducibility of inverted PSCs. We rationalize the difference in widely used perovskite compositions in n-i-p and p-i-n PSCs based on in-situ characterizations. Finally, I will also discuss our approaches toward reproducible fabrication of PSCs.
2-Dimensional Palladium Organometallic Framework Generated Via C-H Activation for Electrochemical Syngas Production from CO2
Authors: Jung Jong-Yeong , Kim Jaewook , Song Hyunjoon
Published: December 2024

Noble metal catalysts have been recognized for their exceptional catalytic activity and efficiency, sparking extensive research efforts. Recently, there has been a notable shift towards utilizing noble metal catalysts supported on stable materials, particularly within the realm of heterogeneous catalysts. Metal-Organic Frameworks (MOFs) have emerged as promising candidates in this regard, offering versatile platforms that serve as porous substrates for dispersing external noble metal species. Various methodologies have been developed to fabricate MOF-based noble metal catalysts, including the introduction of metal nanoparticles, the anchorage of metalloligands, and the utilization of desired metal clusters within the framework. However, because MOFs require metals to form their structures, the introduction of metal nanoparticles and the use of metalloligands necessarily entails the use of undesired metals. Therefore, while it is attractive to synthesize MOFs composed only of desired noble metals, direct synthesis of noble metal-based MOFs has been rarely reported due to significant synthetic challenges arising from the self-assembly of noble metal nanoparticles during solvothermal reactions.

Considering the chemical softness of noble metals, expanding the range of metal–ligand bonds to include chemical soft bonds is crucial for diversifying linkages and incorporating metal atoms as low-valent metal ions and noble metals. Beyond traditional metal–oxygen and metal–nitrogen bonds with carboxylates and azolates, organometallic metal–carbon (M–C) bond connecting crystalline frameworks has gained attention. However, due to the scarcity of multivalent ligands for the M–C bond, generating organometallic frameworks with a single organic linker presents synthetic challenges.

Herein, we found a new synthetic strategy applying organometallic chemistry. We successfully synthesized a Pd organometallic framework, PdOF-1, with a terephthalic acid (H2bdc), one of the most common ligands used for MOFs. PdOF-1 crystals were obtained through a one-pot solvothermal reaction of Pd acetate and H2bdc in dimethyl sulfoxide. Via Pd-catalyzed ortho C–H activation directed by carboxylic acid, Pd–C bonds were formed which directly connected bdc and Pd atoms. The framework comprises atomically dispersed Pd atoms forming organometallic Pd–C bonds, constituting a 2D network with the C2/c space group. As a result, PdOF-1 showed electrochemical CO2 reduction to produce syngas (H2/CO = 0.98) at a low potential of −0.33 V vs. RHE. This work not only presents a rare Pd organometallic framework, but also suggests a synthetic strategy to synthesize noble metal networks with M–C bonds and atomically dispersed noble metals.
Maturation of MOF-Based Sensors for the Electrical Detection of Gaseous Products
Authors: Schindelholz Mara E. , Percival Stephen J. , Hurlock Matthew J. , Christian Matthew S. , Small Leo J. , Nenoff Tina M.
Published: December 2024

The advanced in situ detection of gaseous pollutants, such as NOx, is of great interest in many applications, including the automotive, manufacturing, energy, and defense industries. Current challenges with gas sensors include everything from power consumption, lifetime, and chemical fouling considerations to signal interference from other secondary gases present in complex environments. In this study, we continue the advancement of our low power metal oxide framework (MOF)-based sensors, previously successfully demonstrated for gaseous I2 and NO2 detection.1-5 The sensors, composed of Pt interdigitated electrodes (IDEs) with a nanoporous adsorbent layer, can be tuned to selectively adsorb gases of interest through judicious material selection, and the electrical response directly correlated to gas concentration. The sensors have been successfully demonstrated for the selective detection of trace NOx (1ppm), in complex environments (e.g., presence of H2O, CO2, SO2).6 Direct growth of thin MOF films on surface functionalized IDEs has been shown to result in increased sensor sensitivity and a faster response time.7 Our recent work has investigated the long-term durability and sensitivity of the sensors to NOx, when exposed to dry and humid environments at room temperature and 74°C over the course of three months. It was observed that the Ni-MOF-74-based sensors exhibited superior sensitivity in comparison to Mg-MOF-74 on initial exposure to NOx. On the other hand, the Mg-MOF-74-based sensors exhibited less degradation of the sensor response from prolonged humidity exposure. These findings led to our current work, exploring mixed metal MOF-on-MOF sensors for optimization of both sensor response and long-term performance. Preliminary experimental and modeling performed to elucidate the influence of metal mixing on these metrics will be presented. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.

References

Small, L.J and Nenoff, T.M., ACS Appl. Mater. Interfaces, 2017, 9 (51), 44649.

Small, L.J., et al., Meso. Mater., 2019, 280, 82.

Small, L.J., et al., ACS App. Mater. Interfaces, 2019, 11 (31), 27982.

Small, L.J., et al., Funct. Mater., 2020, 30 (50), 2006598.

Small, L.J., et al., I&ECR, 2021, 60, 21, 7998.

Small, L.J., et al., ACS Appl. Mater. Interfaces, 2023, 15 (31), 37675.

Henkelis, S.E, et al., Membranes, 2021, 11 (3), 176.

Percival, S.J., et al., I&ECR, 2023, 62, (5), 2336.
Enhancing Selectivity and Efficiency in Carbon Dioxide Reduction to C2 Products through Spatial Confinement of Copper Species
Authors: Hung Sung-Fu
Published: December 2024

Carbon dioxide reduction reaction (CO2RR) into multi-carbon products such as ethylene and ethanol offers a promising avenue for both mitigating CO2 levels in the atmosphere and producing valuable chemicals. Techno-economic assessments indicate that achieving a current density of 300 mA/cm2 in CO2RR to C2+ products is crucial. Recently, we have made strides in enhancing both current density and selectivity through the utilization of flow systems and the implementation of spatial confinement strategies.

Our approach involves synthesizing copper nanoparticles within carbon nanotubes (CNTs) to mitigate overpotential and enhance the selectivity of multi-carbon product formation. The confined environment within the CNTs serves to concentrate CO2RR intermediates, thereby promoting the activity and selectivity of the carbon dioxide reduction reaction. As a result, our composite catalyst demonstrates a Faradaic efficiency of 73.96% and a current density of 591.68 mA/cm2for C2 products at 800 mA/cm2.

Further enhancing the activity of copper species, we design a tubular metal-organic-framework (MOF)-derived copper catalyst that generates copper nanoclusters within its structure, leveraging the spatial confinement effect to boost the activity and selectivity of CO2RR. This catalyst achieves a Faradaic efficiency of 71% and a current density of 710 mA/cm2 for C2 products at 1000 mA/cm2.

Analysis of operando Raman spectra, reveals crucial intermediates generated during CO2RR, shedding light on mechanisms underlying overall catalytic activity improvements. Through these spatial confinement strategies, we aim to significantly reduce carbon dioxide, advance towards achieving net-zero emissions, and pave the way for the industrialization of CO2RR.
Dicarboxylferrocene Ligand Promoted Structural Reconstruction in Bimetallic Nico-Based Metal Organic Framework for Energy-Saving H2 Production via Urea Oxidation Reaction
Authors: Ting Jyh-Ming , Chen Hui-Chuan , Nguyen Thi Xuyen
Published: December 2024

Water electrolysis involving low energy barrier anodic urea oxidation reaction (UOR) is a promising way for hydrogen production. Among various UOR electrocatalysts, metal organic framework (MOF) shows unique features of high specific surface area, large porosity, and tunable electronic structure, providing abundant metal active sites for achieving high-performance electrocatalytic activity. Herein, we demonstrate redox-active dicarboxylferrocene (DFc) ligand modified NiCo-based MOF as an electrocatalyst toward UOR. The DFc ligand not only provides additional active sites for catalysis and intermediate adsorption/desorption, but also enhances the charge transfer, thus significantly improving the UOR activity. The NiCo-MOF-DFc demonstrates an outstanding UOR performance with an ultra-low potential of 1.23 V at 10 mA cm−2, a small Tafel slope of 50.8 mV dec−1, and an excellent stable durability. In-situ and ex-situ analyses, and density functional theory calculation reveal that the introduction of DFc ligand facilitates the reconstruction of MOF into metal oxyhydroxide, which are the active sites for the oxidative reaction. This study opens a new route for future development of advanced UOR electrocatalysts via ligand-engineering.
Enhancing Photoelectrochemical Water Splitting Efficiency of ZnO P-N Homojunction Nanorod Arrays By Piezotronics and Piezocatalyst
Authors: Liu Chuan-Pu , Lin Yi-Miao , Hsiao Yu-Liang
Published: December 2024

Due to the increasing demand for clean energy sources, hydrogen has received considerable attention due to its high energy density and only water byproduct. Among all the hydrogen generation methods, Photoelectrochemical (PEC) water splitting driven by solar light is promising for green hydrogen production. In this study, the efficiency of ZnO-nanorod arrays-based PEC systems is first enhanced by forming ZnO p-n homojunction via a two-step hydrothermal method with Sb doping, in favor of the separation of photo-generated carriers due to the built-in electric field. Additionally, in the context of piezotronics and piezocatalyst, applying external forces during water splitting could modulate the Schottky barrier height and the width of the depletion region, so that carrier separation and catalytic reaction is further improved. The synergistic effect between the built-in electric field and stress-induced Schottky barrier modulation leads to enhancement in photocurrent. This study provides a facile method for synthesizing ZnO p-n homojunctions and contributes to the improvement of output efficiency in PEC water splitting systems.
Engineering of High-Surface Area Carbons Supports with Optimized Properties for Pt/C PEMFC Catalysts Design
Authors: Martin Julian , Küspert Sven , Christmann Kläre , Marić Robert , von Holst Miriam , Fadlullah Hassan , Vierrath Severin , Zamel Nada , Fischer Anna
Published: December 2024

Proton Exchange Membrane Fuel Cells (PEMFCs) for heavy-duty applications require the development of carbon-supported Pt-based electrocatalysts for oxygen reduction reaction (ORR) with enhanced activity and prolonged durability compared to current systems.[1,2] While various factors affect the performance of the catalyst layer within the Membrane Electrode Assembly (MEA); at the catalyst level, the size and distribution of Pt nanoparticles on the carbon support, as well as the properties of the carbon support itself, play a crucial role in determining the overall performance. Therefore, engineering of the carbon support, including morphological and physicochemical properties, is a potent strategy not only to enhance Pt nanoparticle dispersion, anchoring, and positioning but also to mitigate ionomer poisoning, thereby maximizing Pt utilization for ORR.[3,4,5] Additionally, carbon support engineering directly influences the structural properties of the catalyst layer, which is pivotal for improving accessibility and oxygen transport at the MEA level.

In this contribution, we introduce the synthesis of a high-surface area carbon support (hs-C) with customized morphological and physicochemical characteristics. Our method enables precise adjustment of critical support parameters, leading to an unparalleled toolbox for advanced Pt/C catalyst design.

We thoroughly examined the morphological and physicochemical properties of the resulting "designer" carbons and derived Pt/hs-C catalysts. A systematic investigation of the impact of the carbon support properties on the ORR catalytic activity in acidic media at the Rotating Disk Electrode (RDE) level was conducted as well as structure-function relationships at the MEA level derived, demonstrating the huge potential of carbon support design in improving Pt utilization and PEM-FC performance.

Note: J.M., S.K. and K.C. have equally contributed to this work.

References

[1] D.A. Cullen, K.C. Neyerlin, R.K. Ahluwalia, R. Mukundan, K.L. More, R.L. Borup, A.Z. Weber, D.J. Myers, A. Kusoglu, A. Nature Energy. 2021, 6, 462–474.

[2] K. Kodama, T. Nagai, A. Kuwaki, R. Jinnouchi, Y. Morimoto, Nature Nanotechnology, 2021, 16, 140–147.

[3] P. Lang, N. Yuan, Q. Jiang, Y. Zhang, J. Tang, Energy Technology, 2020, 8, 1900984.

[4] S. Ott, A. Bauer, F. Du, T.A. Dao, M. Klingenhof, A. Orfanidi, P. Strasser, ChemCatChem, 2021, 13, 4759–4769.

[5] Islam, M. N.; Mansoor Basha, A. B.; Kollath, V. O.; Soleymani, A. P.; Jankovic, J.; Karan, K. Nat. Commun.
2022, 13 (1), 6157.
Nanoporous Niobium Oxide Coating on Pt/C to Increase Catalyst Durability in Oxygen Electroreduction
Authors: Jasim Ahmed , Xing Yangchuan , Wortman James , Ramaswamy Nagappan
Published: December 2024

Platinum-based catalysts show high activity for the oxygen reduction reaction (ORR) in Proton Exchange Membrane (PEM) fuel cells. However, platinum nanoparticles (Pt NPs) are prone to dissolution and agglomeration in the high potential, temperature, and acidic environment of the PEM fuel cell cathode. In this work, Pt/C was coated by ~2.5 nm nanoporous niobium oxide to stabilize the Pt NPs, denoted NbOx@Pt/C. The coated catalysts were annealed at 400 and 600 °C. Compared to the bare Pt/C, X-ray diffraction data for NbOx@Pt/C-400 have shown no change in crystallinity whereas NbOx@Pt/C-600 has shown NbOx phase transition from amorphous to crystalline. X-ray photo spectroscopy (XPS) characterization has shown a positive binding energy shift in Pt 4f and a negative binding energy shift in Nb 3d in NbOx@Pt/C-600 as compared to that of NbOx@Pt/C-400 or Pt/C. The NbOx@Pt/C-600 catalyst shows underpotentially hydrogen adsorption indicating possible proton transport in the niobium oxide layer, but less slightly ORR activity compared to pure Pt/C. Hypothetically, this could be due to the facile diffusion of protons through the porous metal oxide coating compared to the dissolved oxygen gas that has larger molecular sizes. Nonetheless, NbOx@Pt/C-600 has shown a close to zero loss in ECSA after 30K cycles in durability test whereas Pt/C has a loss of ~30%. The high stability is attributed to the NbOx layer that protects Pt NPs from corrosion and degradation. This work demonstrated an approach that is a step forward in designing a durable catalyst for ORR in PEM fuel cells.

Keywords: Pt catalysts, Niobium Oxides, Durability, Nanoporous coating
Elucidating the Evolution of the Iridium Oxide Catalysts’ Surface: From Activation through Operation to Degradation Modes
Authors: Roiron Camille , Wang Cliffton , Zenyuk Iryna V. , Atanassov Plamen , Zargarian Shabnam
Published: December 2024

Iridium oxide nanoparticles as self-supported catalysts for the oxygen evolution reaction (OER) in proton exchange membrane water electrolyzers (PEMWE) have been used for a decade because of their stability in acidic environments. The community has in general accepted that the amorphous and rutile structures of this oxide have distinct intrinsic activity, both in the liquid-electrolyte model system and in membrane electrode assemblies. However, the surface properties that contribute to the higher recorded activity of amorphous iridium oxides are not yet defined. The spectroscopic features of iridium atoms are not very sensitive to changes in the chemical environment, making structural properties difficult to elucidate. The oxygen spectrum, however, provides distinct footprints for amorphous and rutile iridium oxide materials and its features are sensitive to the surface and near-surface environment changes.

In this work, oxygen features are used to identify the surface composition of five commercially available materials consisting of amorphous, rutile, or mixed phases. The spectra of the amorphous (IrOx) and rutile (IrO2) structures present distinct features that are associated with chemical moieties identified using soft X-ray adsorption spectroscopy (1). A peak-fitting model is developed to analyze the X-ray photoelectron spectra (XPS) of the oxygen 1s orbitals. This model is used in this work to characterize and understand the modifications of the iridium oxide surfaces upon surface activation.

During the electrochemical activation of these catalysts, different surface modifications occur depending on the structure of the pristine material. Such surface evolution, which can occur during the first cycles of polarization, renders the rational design of highly active/durable materials difficult. The analysis of the superfine O1s XPS spectra at different stages of activation allows us to understand the structural evolutions leading to activity differences. This work intends to provide sufficient insights for the identification of the intermediate structures responsible for the reactivity and stability of OER catalysts.

(1) Mom, R. V.; Falling, L. J.; Kasian, O.; Algara-Siller, G.; Teschner, D.; Crabtree, R. H.; Knop-Gericke, A.; Mayrhofer, K. J. J.; Velasco-Vélez, J.-J.; Jones, T. E. Operando Structure–Activity–Stability Relationship of Iridium Oxides during the Oxygen Evolution Reaction. ACS Catal.
2022, 12 (9), 5174–5184. https://doi.org/10.1021/acscatal.1c05951.

Figure 1
A Need for Speed: Characterizing Fast Charging Failure Mechanisms in Lithium-Ion Batteries (LIBs) Using X-Ray Microtomography (XRM)
Authors: Bowen Michael
Published: December 2024

The charging rate of traditional lithium-ion batteries is severely limited by a process known as lithium plating, whereby the rate of oxidation of lithium at the positive electrode exceeds the rate of lithium intercalation into the negative electrode active material, leading lithium ions to preferentially reduce and subsequently deposit as lithium metal at the surface of the material. Such plating further slows intercalation, causing an exponential buildup of metal at the electrode interface to the severe detriment of the system’s long-term cyclability, stability, and safety due to the formation of dead lithium and secondary SEI, as well as the increased risk of catastrophic shorting and thermal runaway. It is therefore imperative that the nucleation and growth pathways of lithium plating be fully understood and characterized to properly inform the development of novel, fast charge-capable lithium-ion battery designs.

This work discusses the use of X-ray microtomography to characterize both lithium plating on and lithiation within a graphite electrode at various charge rates. Due to the heterogeneity of these processes, the time and length scales at which they occur vary throughout the electrode and are heavily influenced by the current applied. For the first time ever, we are able to observe such phenomena as they occur using a method we call “rapid scan” X-ray microtomography to improve the temporal resolution of our scans and create operando, actionable datasets that capture the onset and growth of lithium plating and lithiation in three dimensions. Such insights are subsequently compared with and validated against trends observed post-fast charging using a more traditional tomographic approach.

In this manner, we observe and quantify the onset of lithium plating and its growth on both a local and global scale. We are also able to characterize and compare the primary (during-charge) and secondary (post-charge) intercalation of lithium into graphite and find that as much as 70% of plated lithium can be recovered if the system is allowed to rest for 30 minutes prior to discharge. Finally, we combine these two unique datasets to better understand the relationship between regional plating, active material lithiation, and charge rate, and how each of these components impacts the cyclability of the system as a whole.
Design and Manufacturing of Cost-Effective Water Electrolyzers at Industrial Current Densities Via an Ink-Free Integrated Dual Electrode Assembly
Authors: Wang Weitian , Ding Lei , Li Jun , Xie Zhiqiang , Mench Matthew M , Zhang Feng Yuan
Published: December 2024

The clean and sustainable “green hydrogen” is highly attractive as an alternative energy.[1] However, the excessive cost of “green hydrogen” hinders its large-scale application, which is limited by the costly membrane electrode assembly (MEA) in proton exchange membrane electrolyzer cells (PEMECs).[2, 3] Conventional MEA fabrication involves numerous complex ink processes, resulting in a relatively high manufacturing costs. In addition, the ink-formed catalyst layers usually have poor electron conductivity and relatively large thickness, which causes significant catalyst underutilization.[3, 4] To simplify the manufacturing and increase the catalyst utilization, we revolutionize the conventional MEA via a facile ink-free and cost-effective integrated dual electrode assembly (IDEA) for reducing the costs and enhancing the performance of PEMECs. IDEA not only greatly simplifies fabrication processes of MEAs from over ten steps to three steps but also significantly increases hydrogen production rate simultaneously (45.26% more hydrogen at 1.8 V). Benefiting from the nano-thick catalyst layers, the IDEA can achieve an industrial “overload” current density of 6 A/cm2 at a low cell voltage of 1.82 V with an 83.9% noble catalyst saving, which outperforms most reported PEMECs. Particularly, the degradation rate of IDEA is only 24 μV/h at 1.8 A/cm2.

References

Pivovar, B., N. Rustagi, and S. Satyapal, Hydrogen at scale (H2@ Scale): key to a clean, economic, and sustainable energy system. The Electrochemical Society Interface, 2018. 27(1): p. 47.

Ding, L., et al., Electrochemically grown ultrathin platinum nanosheet electrodes with ultralow loadings for energy-saving and industrial-level hydrogen evolution. Nano-Micro Letters, 2023. 15(1): p. 144.

Mo, J., et al., Discovery of true electrochemical reactions for ultrahigh catalyst mass activity in water splitting. Science advances, 2016. 2(11): p. e1600690.

Yang, G., et al., Role of electron pathway in dimensionally increasing water splitting reaction sites in liquid electrolytes. Electrochimica Acta, 2020. 362: p. 137113.

Figure 1
Stability Study of Doped-PrCoO3 Perovskites as Oxygen Electrodes in Proton Conducting Electrolysis Cells
Authors: Li Meng , Bian Wenjuan , Zhao Zeyu , Ding Dong
Published: December 2024

Within the field of electrochemical systems, perovskite oxides are notable for their high catalytic activity, particularly when they are rich in oxygen vacancies. These materials exhibit oxygen vacancies that have a dual function. These vacancies can enhance targeted reactions by acting as active sites, thereby boosting the overall efficacy of the system. Conversely, they may also initiate a sequence of adverse reactions that weaken the material’s structure and reduce its stability, especially at high temperatures or exposure to high concentration steam or CO2, like the typical operation conditions in proton conducting electrolysis cells (PCECs). Although these materials are widely used as oxygen electrodes in PCECs, the specific structural mechanisms that determine their stability under operation conditions are not well understood. In this work, we employed layered double perovskite PrBa0.5Sr0.5Co1.5Fe0.5O5+δ and rhombohedral perovskite PrNi0.7Co0.3O3+δ to assess their structural stability. The challenging environments of high temperatures and exposure to high concentration steam accelerate potential structural degradation. Through density functional theory calculations and in situ Fourier transform infrared spectroscopy characterization, we demonstrate how lattice octahedra adapt to operational conditions, leading to anisotropic lattice stress and facilitating elemental segregation in different octahedral configurations. Our investigation delves into the atomic-scale intricacies of perovskite oxides, aiming to dissect the interplay between their structure and stability. This understanding could pave the way for developing more robust and effective materials.
Investigating Protonic Surface Exchange Kinetics in Protonic Conducting Electrolysis Cells Using Electrical Conductivity Relaxation
Authors: Meng Yuqing , Deng Hao , Liu Bin , Li Meng , Ding Dong
Published: December 2024

Triple conducting oxides in Protonic Conducting Electrolysis Cells (PCECs) have received considerable attention due to its high activity to steam electrolysis. While extensive research has explored the performance of the air electrode using various methodologies, there are no reports yet on the proton exchange k values of triple-conducting electrode under applied potential by any method to the best of our knowledge. In this study, we propose employing Electrical Conductivity Relaxation (ECR) as a novel approach to investigate protonic surface exchange kinetics under potential. Leveraging state-of-the-art air electrodes as model materials, we conducted protonic hydration processes by transitioning the atmospheric conditions from dry air to humidified air. The evolution of the conductivity relaxation profile was meticulously monitored, and the acquired data was subjected to rigorous analysis through modeling techniques, enabling us to discern the surface exchange rate (k) under varying potentials and steam concentrations. By shedding light on the electrode hydration behavior under semi-working conditions, this work provides valuable insights crucial for the advancement and innovation of next-generation electrodes for PCECs.
Nanoscale Proton-Conducting Oxide Membranes for Low Temperature Water Electrolysis
Authors: Esposito Daniel V. , Cohen Lucas , Jin Jingjing , Dondapati Jesse , Lin Zhexi , Weimer Matthew S , Harris Sara , Dameron Arrelaine A , Junker Sven , Hawkes Justin , Ouimet Ryan J. , Capuano Christopher B.
Published: December 2024

Operating water electrolyzers at higher current densities is an attractive approach to improving the economics of hydrogen production from water electrolysis. Conventional proton exchange membrane (PEM) electrolyzers based on Nafion membranes already operate at relatively high current densities (1.5-2.5 A cm-2), but increasing the current density to 5 A cm-2 or higher would improve the economics even further. Currently, a major limitation of operating low-temperature PEM electrolyzers at such high current densities is the large ohmic drop across the Nafion membrane, which can dramatically lower electrolyzer efficiency. To reduce the membrane resistance and enable efficient operation at high current densities, our team has been exploring the use of nanoscopic proton-conducting silicon oxide (SiOx) membranes. Although the proton conductivity of these oxide membranes is lower than Nafion, we show that their total resistance can be made much lower than conventional Nafion-117 membranes by decreasing their thickness to the nanoscale. The use of sub-micron thick membranes is made possible by the high density of SiOx compared to Nafion, which makes SiOx membranes excellent hydrogen (H2) diffusion barriers for preventing H2 crossover. In this work, we show that the area specific membrane resistance of nanoscale SiOx membranes can be reduced to less than 20% that of Nafion-117 membranes while still maintaining desirable H2 blocking capabilities and avoiding problematic electronic leakage current.
Ag Doped LaMnO3 As a Novel Cathode Material for SOFC Using YSZ Electrolyte
Authors: Sakai Takaaki , Takamatsu Akihiro , Takemura Hiroki , Mitsushio Konosuke , Kishimoto Haruo , Oishi Masatsugu
Published: December 2024

In this work, Ag doped LaMnO3 oxide (La1-xAgxMnO3-d) was synthesized by sol-gel method and the characteristics such as the phase stability, compatibility against YSZ electrolyte, the electronic state of Mn, electrical conductivity and power generation property when used as a cathode of SOFC were investigated. The solubility limit of Ag into LaMnO3 perovskite structure was about 10% (La0.9Ag0.1MnO3-d, LAM01), and the clear reactive phase was not confirmed when LAM01 was mixed with YSZ electrolyte and sintered at 975oC for 100h. The electronic state of Mn was almost same as that of La0.9Sr0.1MnO3-d(LSM01) at room temperature. The main charge carrier of LAM01 was electron hole (h+) and its electrical conductivity was higher than that of LSM01.The power generation property of the SOFC cell using LAM01 cathode showed the similar performance of that of LSM01 cell. In addition, the deposition of Ag metal was not clearly confirmed by the various observation after the power generation test, suggesting that the excellent property of LAM was not caused by the extrusion of Ag nano catalyst from LAM oxide. This work also suggests that the material design of SOFC cell without cathode interlayer is possible by using the dopant such as Ag, which has less reactivity against YSZ electrolyte.
Sr Oxide Nanoparticle Modified Co3O4 as an Active Oxygen Dissociation and Recombination Catalyst for Solid Oxide Reversible Cell
Authors: Narmandakh Khongorzul , Song Jun Tae , Watanabe Motonori , Ishihara Tatsumi
Published: December 2024

Solid Oxide Cells, SOFC and SOEC, are attracting attention in energy conversion and storage systems due to their high efficiency and flexibility in various fuels. However, their performance is decreased by the limited reversibility of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air electrode, particularly at intermediate temperatures because of high overpotential from large activation energy. Therefore, developing an active and reversible air electrode for fast oxygen dissociation/association processes is crucially required. Conventional air electrodes often utilize Co-based perovskites (such as La0.6Sr0.4Co0.2Fe0.8O3−δ and Ba0.5Sr0.5Co0.8Fe0.2O3−δ) due to their high ionic and electronic conductivity, along with good catalytic activity. However, it has been observed that the presence of A-site oxide on the perovskite surface leads to lower catalytic activity. Recent approaches have explored surface modification through infiltration to enhance catalytic activity and stability [1-3]. This study focuses on investigating the cathodic performance of surface-modified B-site oxide, specifically Co3O4 spinel-type oxide, as a model catalyst with SrO modification. Figure 1 illustrates the image of the air electrode aimed in this study. It was found that the power density of the cells in SOFC condition increased after Sr infiltration, which is almost the same performance with SrCoO3 reference cell. Additionally, overpotential was significantly decreased due to the formation of active sites for ORR. For SOEC condition, Sr infiltrated cell reached a reasonable current density compared with bare Co3O4. Also, ohmic and polarization resistances decreased because of better oxygen evolution on the surface. It is found that interface between SrO and Co3O4 is active site for air electrode of solid oxide reversible cell, which is demonstrated by using diffusion of oxygen tracer, 18O.

References

[1] A. Ndubuisi, S. Abouali, K. Singh, and V. Thangadurai, J. Mater. Chem. A. 10, 2196 (2022).

[2] R. Vinoth Kumar, and A.P. Khandale. Renew. Sustain. Energy Rev. 156, 111985 (2022)

[3] D. Dong, L. Xiaxi, Y.L. Samson, G. Kirk, and L. Meilin. Energy Environ. Sci. 7, 552 (2014).

Acknowledgment

This study was financially supported by the New Energy and Industrial Technology Development Organization (NEDO) (No. JPNP20005).

Figure 1
Recycling of Protonic Solid Oxide Cells with Physio-Electrochemical Networks (RSPEN)
Authors: Wu Wei , Wang Wanhua , Aston John , Shi Meng , Diaz Luis A
Published: December 2024

The global shift towards renewable and sustainable energy, with a focus on reducing reliance on fossil fuels and curbing carbon emissions, has led to the rise of hydrogen production via water electrolysis, powered by carbon-neutral sources. As demand for hydrogen grows, so does the need for efficient electrolyzers, such as solid oxide electrochemical cells (SOCs), with projections indicating a significant increase in global hydrogen electrolyzer capacity by 2050. However, the scaling up of SOC production presents challenges, including the need for large-scale raw material production, reliance on commercial products, and environmental impacts of waste. Particularly, over a ton of valuable waste ceramic materials are used per megawatt of SOC stack, necessitating effective recycling methods. Herein we propose a novel, scalable closed-loop recycling method for both proton conducting and oxygen ion conducting SOCs, involving active comminution, followed by electrochemical leaching and cell regeneration using recycled raw materials/precursors. The technology could achieve above 90% electrolyte material recovery, 95% CRM recovery from cathode and = 95% recovery in full cell performance. This technology not only addresses a significant gap in current recycling practices but also sets a precedent for future advancements in the field, potentially influencing broader practices in the recycling of multi-functional ceramic systems.
In Situ Reference Electrodes in Water Electrolysis
Authors: Sherin Billie , Shinde Dipak , Smith Graham
Published: December 2024

The production of green hydrogen using water electrolysis is set to play a vital role in the energy transition from fossil fuels to renewables. However, there is still significant opportunity to improve cell performance and consequently drive down the cost of producing low-carbon hydrogen, especially as new electrocatalysts and other components emerge. In situ reference electrodes are a tool that can be used to better understand the processes taking place within an operating electrolyzer cell. Deeper insights are provided into the processes occurring at the electrodes by enabling experiments that deconvolute the cell voltage into its various contributions and this can be used to map the potential though the thickness of the electrolyzer during operation.1 This deconvolution assists in characterizing new materials and supports optimization of materials selection for efficiency and durability in the operating environment.

This presentation will introduce recent advancements on the application of in situ reference electrodes to electrolyzers, including the design, development, and optimization of in situ reference electrodes for both alkaline and polymer electrolyte membrane water electrolyzers. The example data in Figure 1 shows 3 repeats of a deconvoluted polarization curve of an alkaline water electrolyser cell with nickel alloy electrodes on both anode and cathode, demonstrating how the technique enables a more insightful analysis of the behaviour of the cell.

1. Becker, H. et al. Energy Environ. Sci., 2022, 15, 2508-2518

Figure 1
Thermodynamic Approach to Optimal Water Management for Fuel Cell Electric Vehicles
Authors: Park Kyuhyung , Oh Jungrok , Yang Kwonwoo , Um Sukkee
Published: December 2024

A systematic, multicomponent model has been developed to investigate optimal water management for fuel cell electric vehicles. The water management strategies focus on manipulating thermodynamic states to provide the adequate requirements of fuel cells. A pseudo-2D fuel cell water transfer model, a shell and tube type membrane humidifier model, and a centrifugal compressor model are mathematically developed and solved using MATLAB to achieve an integrated thermodynamic approach based on system piping and instrumental diagrams(P&ID). Each component model is validated using published experimental data with good agreement. In the air supply system, the required humidity at the fuel cell channel inlets is theoretically predicted under low heating value operating fuel cells. Subsequently, the optimal mass flow rate of the compressor is suggested to cover a wide range of conditions. Additionally, the recirculated gas is bypassed to control the humidification levels of the humidifier based on the required humidity at the fuel cell channel inlets. The results show the thermodynamic states within system in accordance with the optimal operation conditions of the component. This systematic approach presents significant algorithms for optimizing water distributions in vehicular fuel cell systems.