bluuebunny/crossref_metadata_2025 huggingface dataset:
Decoding the Ceramics Influence in the Composite Electrolytes
Authors: Chavan Kanchan , Barai Pallab , Kim Hong-Keun , Srinivasan Venkat
Published: November 2022

As Lithium-Ion Batteries (LIBs) becomes an essential part of the everyday life, fireproof electrolytes have become an important component of the next generation battery design without compromising the performance of the battery. Composite electrolytes (CEs), consist of polymer electrolytes with highly conducting ceramic particles are promising candidates to substitute currently commercialized LIBs with liquid electrolytes. So far, experiments with CEs have discovered positive and negative effect on the overall conductivity of the CEs in the presence of ceramic particles.1–4 Therefore, exists the conflict weather the CEs are the solution to overcome the disadvantages of all-liquid and all-solid electrolytes.

In this work, a 2-Dimensional CE with a uniform ceramic particle size distribution is studied via continuum modeling. we analyze the effect of interface between polymer and ceramic particle on the overall conductivity and transference number of the CEs to guide experimentalist to fabricate these interfaces carefully. It is concluded that the interplay between ohmic resistance and polymer conductivity at the polymer and ceramic particle interfaces can explain the conflicts observed in the literature. The Ohmic resistance at the interface is a critical parameter that determines whether ceramic particles enhance the overall conductivity or not. Finally, CEs does meet the criteria of the conductivity and transference number requirement in order to use in the EVs.5

References:

(1) Cheng, S. H.-S.; He, K.-Q.; Liu, Y.; Zha, J.-W.; Kamruzzaman, M.; Ma, R. L.-W.; Dang, Z.-M.; Li, R. K. Y.; Chung, C. Y. Electrochemical Performance of All-Solid-State Lithium Batteries Using Inorganic Lithium Garnets Particulate Reinforced PEO/LiClO4 Electrolyte. Electrochimica Acta
2017, 253, 430–438.

(2) Zagórski, J.; López del Amo, J. M.; Cordill, M. J.; Aguesse, F.; Buannic, L.; Llordés, A. Garnet–Polymer Composite Electrolytes: New Insights on Local Li-Ion Dynamics and Electrodeposition Stability with Li Metal Anodes. ACS Appl. Energy Mater.
2019, 2 (3), 1734–1746.

(3) Bonilla, M. R.; García Daza, F. A.; Ranque, P.; Aguesse, F.; Carrasco, J.; Akhmatskaya, E. Unveiling Interfacial Li-Ion Dynamics in Li 7 La 3 Zr 2 O 12 /PEO(LiTFSI) Composite Polymer-Ceramic Solid Electrolytes for All-Solid-State Lithium Batteries. ACS Appl. Mater. Interfaces
2021, 13 (26), 30653–30667.

(4) Choi, J.-H.; Lee, C.-H.; Yu, J.-H.; Doh, C.-H.; Lee, S.-M. Enhancement of Ionic Conductivity of Composite Membranes for All-Solid-State Lithium Rechargeable Batteries Incorporating Tetragonal Li7La3Zr2O12 into a Polyethylene Oxide Matrix. J. Power Sources
2015, 274, 458–463.

(5) Kim, H.-K.; Srinivasan, V. Status and Targets for Polymer-Based Solid-State Batteries for Electric Vehicle Applications. J. Electrochem. Soc.
2020, 167 (13), 130520.
Finite-Element Simulation for Ion Co-Intercalation Chemistry on Si Anode at Lithium-Ion Half-Cell
Authors: Yang Zicheng , Cora Saida , Briselli Vincent , Sa Niya
Published: November 2022

The increasing demand for higher capacity energy storage technologies is rapidly becoming an important consideration in the development of EV and related energy storage devices. Silicon is one promising solution as an earth-abundant element with a higher capacity than the more commonly used graphite anode of a lithium-ion battery. However, silicon anodes face unique challenges with volume expansion, notable during lithium ion intercalation and the stability of the SEI layer. To solve this problem, some recent research efforts discovered introducing a co-intercalation ion in the traditional lithium electrolyte Gen2 increases the coulombic efficiency, capacity, and stability of the silicon anode, but its mechanism of action remains unclear.

In this work, in combination with experimental measurements we demonstrate the use of Newman's P2D Lithium Model in COMSOL together with the Butler-Volmer equation and concentrated solution theory to describe cation co-intercalation into the porous silicon anode material. Experimental data indicates that phase formation and transformation coincide with ion insertion, as reflected in the current response signal. Both the original ion intercalation and the foreign ion intercalation are reflected by CV generated by our model under the influence of model parameters, such as the variable speed of potential changed per second. As designed, our model can be extended towards general application in the cointercalation system and understanding of the foreign ion effect.
Insoluble Solid Organic Catalysts for Non-Aqueous Lithium-Air Batteries
Authors: Renault Stéven , Poizot Philippe , Castro Laurent
Published: November 2022

The chemistries based on the Li-O2 couple in aprotic electrolyte seem promising to provide ultrahigh-energy density values and outperform the current LIB technology. The main targeted application is to power electrified vehicles, with the hope of achieving high driving range. Unfortunately, serious side-reaction issues have plagued their development for practical applications so far. For example, during the discharge process, undesired insulating products are formed instead of lithium peroxide. Moreover, the blocking/clogging effect on the air electrode due to a deposition process leads to an overpotential during both the discharge (Oxygen Reduction Reaction: ORR) and charge processes (Oxygen Evolution Reaction: OER), which results in electrode degradation, electrolyte decomposition and precocious cell failure.

A promising strategy to reduce these overpotentials is the use of organic redox mediators by taking advantage of their tunability. For several years, our group has been developing lithiated organic materials with average redox potentials close to the O2/Li2O2 redox couple (2.96 V vs Li+/Li0). We here report the effect of Li2DAnT (alone or in combination with Li4-p-DHT [1]) and Li4-DHNDC [2] on the cycling behavior of Li-O2 batteries and their influence on ORR and OER processes.

References

1) S. Renault, et al., PCT Patent WO 2021/148835 A1.

2) S. Renault, et al., PCT Patent WO 2021/148836 A1.

Figure 1
Iron Fluoride Confined in Carbon Nanofibers for Lithium and Sodium Battery Cathodes
Authors: Fu Wenbin , Sun Zifei , Magasinski Alexandre , Yushin Gleb
Published: November 2022

Today, lithium (sodium) battery cathodes based on the intercalation/deintercalation of lithium (sodium) ions are approaching their instinctive limits, which remains a big challenge for the development of next-generation batteries. Iron fluorides (FeF2, FeF3), a potential alternative to current intercalation cathodes, are believed to offer much higher capacity and higher energy due to their reversible conversion reactions during charging/discharging. However, their structural degradation and capacity fading upon cycling could block the road to future applications.

To address these issues, we developed a stable iron fluoride cathode based on nanoconfined FeF3 in carbon nanofibers for lithium and sodium batteries. The produced FeF3
/C nanocomposite is free-standing and can be produced using an electrospinning-based strategy with post carbonization and fluorination process. When tested in lithium cells, the nanocomposite can exhibit a high specific capacity up to 550 mAh g–
1 and a cycle stability over 400 cycles [1]. When tested in sodium cells, the nanocomposite can deliver a high specific capacity of 230 mAh g–
1 in sodium-difluoro(oxalato)borate (NaDFOB) electrolyte [2]. The performance especially cycle stability was further improved by atomic layer deposition (ALD) of Al2O3 coating on nanofiber surface [3]. We find the coating can reduce the direct contact between active material and liquid electrolyte, minimize active material dissolution and significantly improve the overall performance.

[1] W. Fu, E. Zhao, Z. Sun, X. Ren, A. Magasinski, G. Yushin, Iron Fluoride–Carbon Nanocomposite Nanofibers as Free-Standing Cathodes for High-Energy Lithium Batteries, Advanced Functional Materials 28 (2018) 1801711.

[2] Z. Sun, W. Fu, M.Z. Liu, P. Lu, E. Zhao, A. Magasinski, M. Liu, S. Luo, J. McDaniel, G. Yushin, A nanoconfined iron(iii) fluoride cathode in a NaDFOB electrolyte: towards high-performance sodium-ion batteries, Journal of Materials Chemistry A 8 (2020) 4091-4098.

[3] Z. Sun, M. Boebinger, M. Liu, P. Lu, W. Fu, B. Wang, A. Magasinski, Y. Zhang, Y. Huang, A.Y. Song, M.T. McDowell, G. Yushin, The roles of atomic layer deposition (ALD) coatings on the stability of FeF3 Na-ion cathodes, Journal of Power Sources 507 (2021) 230281.
A New Class of 2D Materials - Quaternary Derived Nanostructures - and Their Polysulfide Anchoring Capabilities in Lithium Sulfur Batteries
Authors: Cardoza Neal A. , Pereira Rhyz , Badr Hussein , Pai Rahul , Natu Varun , Carey Michael , Barsoum Michel W. , Kalra Vibha
Published: November 2022

Metal-sulfur battery chemistries have garnered a lot of interest due to their 5-10 fold higher theoretical energy densities compared to state-of-the-art lithium-ion batteries, in addition to the abundance and environmental benignity of sulfur. However, the insulating nature of sulfur, the formation and shuttling of polysulfides, are still major drawbacks. In this work we started with quaternary ammonium salts or quat derived nanostructures (QDNs), synthesized using a facile bottom-up reaction, directly from commercial 3D bulk solids1. This approach leads to better functionalization, facile tunability, and higher active sites. Moreover, these materials self-assemble into a plethora of microstructures – from individual anatase-based 1D nanoribbons 6x102 Å in cross-section to 2D flakes to mesoscopic particles, both comprised of 1D nanoribbons - depending on the synthesis and washing parameters. Here we use QDNs made from commercial titanium carbide (TiC) reacted at 50℃ for 5 days, washed with 5M lithium chloride, and freeze dried after filtration. These TiC QDNs are simply hand ground with sulfur in a 50:50 ratio by weight, to create a sulfur TiC QDN composite. This composite was then used to make a slurry with carbon black and binder, in a ratio of 70:20:10 respectively. We obtain specific capacities of 800 mAh.g-1 at 0.5 C after 300 cycles seen in Figure 1. The anatase-based 1D nanoribbons, that assemble into 2D layers, traps the polysulfides by forming thiosulfate species and Lewis acid-base interactions with the titanium, confirmed by post-mortem X-ray photoelectron spectroscopy. Additionally, these interactions were confirmed visually with the 2D QDNs adsorbing polysulfides, after 7 days the 0.5mM solution of polysulfides appeared clear in comparison to the still yellow hue of the polysulfides seen with carbon black seen in Figure 2. These interactions are further enhanced with the added functionalization of the 2D materials using non-polar di(hydrogenated tallow)benzyl methyl ammonium chloride (DHT) surfactant molecules.

1. H. O. Badr et al., Materials Today, S1369702121003813 (2022).

Figure 1
Carbon-Free High-Performance Cathode for Solid-State Li–O2 Battery
Authors: MA Sang Bok , Kim Mokwon , Lee Hyunpyo , Kwon Hyuk Jae , Yoon Gabin , Park Jung O. , Seo Dong-Hwa , Im Dongmin
Published: November 2022

The development of a cathode for solid-state lithium-oxygen batteries has been hindered in practice by a low capacity and limited cycle life despite their potential for high energy density. Here, a previously unexplored strategy is proposed wherein the cathode delivers a specific capacity of 200 milliampere hour per gram over 665 discharge/charge cycles, while existing cathodes achieve only ~50 milliampere hour per gram and ~100 cycles. A highly conductive mixed ionic-electronic conductors (MIECs) are designed as a carbon-free cathode by first-principles calculations with a density functional theory (DFT) and nudged elastic band (NEB) to avoid the degradation associated with carbonaceous materials, implying an improvement in stability during the electrochemical cycling [1]. In addition, water vapor is added into the main oxygen gas as an additive to change the discharge product from growth-restricted lithium peroxide to easily grown lithium hydroxide, resulting in a significant increase in capacity [2]. Thus, the proposed strategy is effective for developing reversible solid-state lithium-oxygen batteries with high energy density. We will discuss on the systematic materials design and their electrochemical properties for solid-state lithium-oxygen batteries at the meeting.

References

[1] Sang Bok Ma et al., Advanced Energy Materials, 10 (2020) 2001767.

[2] Mokwon Kimet al., Science Advances, in press.

Figure 1
Investigation of Underlying Reaction Mechanism in Li-S Battery Under Extreme Conditions
Authors: Adhikari Pashupati Raj , Pathak Anil Daliprasad , Choi Wonbong
Published: November 2022

Recent developments in electric vehicles (EVs) and portable electronics, lithium-sulfur (Li-S) battery has emerged as a promising candidate due to its high theoretical energy density. To achieve the practical high energy density (~500 Wh kg-1) in Li-S battery, high active material (sulfur) loading (> 6 mg cm-2), effective sulfur utilization, and low electrolyte-to-sulfur (E:S) ratio (<3 μL mg-1) should be achieved. Primarily, high sulfur loading, low E:S ratio, high sulfur content, and an optimum current rate are needed to achieve high energy and power density. In this work, we experimentally investigate polysulfide conversion mechanism that takes place in Li-S battery under extreme, both electrochemical and operating, conditions. An extreme threshold with respect to maximum and minimum sulfur loading and E:S ratio of below 3 or close to zero are thoroughly investigated. It is observed that the underlying polysulfide conversions altered when cell was operated at extreme conditions (e.g. E:S ratio). Furthermore, this work is expected to provide a critical scientific insight through advanced characterization techniques (e.g. in-situ Raman spectroscopy) to mechanistically understand the reaction kinetics in Li-S battery.
Potential of Zero Charge Measurement By Second Harmonic Generation
Authors: Xu Pengtao , Suntivich Jin
Published: November 2022

When an electrode contacts an electrolyte, an interfacial electric field forms. This interfacial field can polarize the electrode’s surface and nearby molecules, but its effect can be countered by applying countering potential. We present an optical method for quantifying the value of this countering potential (“potential of zero charge”, pzc). Our approach uses phase-sensitive second harmonic generation to determine the potential where the interfacial electric field vanishes, using Pt-water interface as a model system. Our experiment reveals that the value of the pzc of the Pt/water interface and further shows that it is pH-independent from pH 1 to 13 on an absolute potential scale. We will discuss this result from the consideration of the solid-liquid interface, including the electrode materials and interfacial water structure. Our work provides a materials-agnostic tool for quantifying the interfacial electrical field at a solid-liquid interface and confirms the view that the interfacial electric field during hydrogen electrocatalysis is more intense in alkaline than acid.
(Invited) Development of a Simple and Rapid Diagnostic for Redox-Flow-Battery Cells
Authors: Perry Mike L. , Darling Robert M.
Published: November 2022

Prof. Robert Savinell has made many important contributions to fuel-cell and flow-battery systems. Both of these systems utilize electrochemical flow cells to either generate or store electricity. Because of this commonality, one can leverage concepts used in one for adoption in the other. An important topic for any electrochemical system is durability. A considerable amount of work has been on this topic with polymer-electrolyte fuel cells (PEFCs); in fact, a textbook devoted to this topic was published over a decade ago [1]. However, despite a recent renaissance in redox-flow-battery (RFB) technologies, assessing the durability of RFB cells is a topic that has not received much attention in the open literature, to date, and further research is needed to better understand dominant degradation mechanisms [2, 3].

A simple and fast diagnostic tool has been developed for analyzing polymer-electrolyte fuel-cell degradation [4, 5]. The tool is based on analyzing changes in polarization curves of a cell over its lifetime. Using the polarization-change curve methodology, the primary mechanism for degradation (kinetic, ohmic, and/or transport related) can be identified. This technique can also be applied to RFB cells, which will be the focus of this presentation. This diagnostic tool provides a simple method for rapid determination of primary degradation mechanisms. Areas for more detailed future investigations shall also be summarized.

References

Modern Topics in Polymer Electrolyte Fuel Cell Degradation, Mench, M.; Kumbur, E.; and Veziroglu, T.; Editors; Elsevier, Denmark (2011).

Yuan, X.-Z.; Song, C.; Platt, A.; Zhao, N.; Wang, H.; Li, H.; Fatih, K.; Jang, D.; “A review of all-vanadium redox flow battery durability: Degradation mechanisms and mitigation strategies,” J. Energy Res., 43 (2019) 6599−6638.

Yao, Y.; Lei, J.; Shi, Y.; Ai, F.; Lu, Y. C.; “Assessment methods and performance metrics for redox flow batteries,” Energy, 6 (2021) 582−588.

L. Perry, R. Balliet, and R. Darling, “Experimental Diagnostics and Durability Testing Protocols,” a chapter in [1].

M. Pant, Z. Yang, M. L. Perry, and A. Z. Weber, “Development of a Simple and Rapid Diagnostic Method for Polymer-Electrolyte Fuel Cells,” J. Electrochem. Soc., 165 (2018) F3007.
Mediating Anion-Cation Interactions to Improve Aqueous Flow Battery Electrolytes
Authors: Reber David , Thurston Jonathan R. , Becker Maximilian , Pach Gregory F. , Wagoner Marc E. , Robb Brian H. , Waters Scott E. , Marshak Michael
Published: November 2022

Development of energy dense aqueous redox flow batteries is held back by high cost, chemical instability of highly soluble active compounds, or solubility limits of more suitable active materials. Here, we study solubilizing effects of inexpensive polar additives on metal-organic chelates based on aminopolycarboxylate ligands, a particularly promising family of compounds for application in negative electrolytes in near neutral pH aqueous flow batteries with demonstrated discharge voltages as high as 2.1 V.[1] Upon addition of certain additives, cation-dependent solubilities of chromium 1,3-propylenediaminetetraacetate (CrPDTA) and chromium ethylenediaminetetraacetate (CrEDTA) salts are enhanced by 60% and 125%, respectively, resulting in maximum solubilities of e.g., 1.5 м for KCrPDTA and 2.2 м for NaCrEDTA. We elucidate the mechanism behind enhanced solubility of aminopolycarboxylate chelates and study the impact of the additive on the electrochemical performance of near neutral pH flow batteries, demonstrating 50% higher anolyte capacities, up to 40 Ah L−1, than previously reported for this class of materials. In capacity balanced full cells, using ferrocyanide catholytes, we observe excellent Coulombic efficiencies >99.6% and voltage efficiencies >78% at average discharge voltages of ca. 1.5 V when cycling at 100 mA cm−2. Peak discharge power densities of >400 mW cm−2 further highlight the potential of our facile and cost-effective approach. Finally, we discuss avenues for future work to further exploit the solubilizing effect described herein.

References:

[1] B.H. Robb, J.M. Farrell, M.P. Marshak, Chelated chromium electrolyte enabling high-voltage aqueous flow batteries, Joule
2019, 3, 2503–2512.
(Invited) Biomolecular Engineering for Electrochemical Applications in Fuel Cells/Electrolyzers and Beyond
Authors: Renner Julie N.
Published: November 2022

Control of ionomer thin film structures on metal surfaces is pivotal for efficient performance in electrochemical devices such as fuel cells and electrolyzers. Unfortunately, the assembly of these thin film structures is difficult to control using conventional methods and ideal arrangements remain unknown. Engineered polypeptides have emerged as powerful biomolecular tools in electrode assembly because binding sites and polypeptide structures can be easily modulated by changing the amino acid sequence. However, no studies have been conducted showing polypeptides can be engineered to interact with ionomers, attach them to metal surfaces, and control their arrangement. Our lab has recently developed this technology, using an elastin-like polypeptide to bind to metals, and bind to acidic and basic ionomer via ionic interactions. We use a quartz crystal microbalance with dissipation to provide detailed information about the loading, thickness, and binding behavior of the polypeptide and ionomer layers. We also use atomic force microscopy and grazing-incidence small-angle X-ray scattering to understand the impact of the biomolecules on ionomer phase separation. Finally, we have analyzed the performance (ionic conductivity) of the assembled films using interdigitated electrodes and electrochemical impedance spectroscopy. Through these techniques, we show that 1) our biomolecular system is highly flexible, easily adapting to different materials, 2) the polypeptide sequence can dictate ionomer phase separated structures, and 3) this system can be used to improve the performance of ionomer thin films and gain structure-function understanding. Generally, our results demonstrate that engineered polypeptides are promising tools for ionomer control in electrode engineering for fuel cells/electrolyzers and beyond. Furthermore, this work demonstrates that the creative combination of applied electrochemistry and biomolecular engineering supported and encouraged by leaders in each field can lead to unique research pathways that benefit heath, energy and the environment.
(Invited) Using Ambient Pressure XPS to Probe the Solid/Gas and Solid/Liquid Interface Under in Situ and Operando Conditions
Authors: Crumlin Ethan J.
Published: November 2022

Interfaces play an essential role in nearly all aspects of life and are critical for electrochemistry. Prof. Robert Savinell has played a pivotal interface to me in the role of mentorship in both life and electrochemistry, and I look to honor his contributions to both through this talk. Electrochemical systems ranging from high-temperature solid oxide fuel cells (SOFC) to batteries to capacitors have a wide range of important interfaces between solids, liquids, and gases, which play a pivotal role in how energy is stored, transferred, and converted. I will share the use of ambient pressure XPS (APXPS) to directly probe the solid/gas and solid/liquid electrochemical interface. APXPS is a photon-in/electron-out process that can provide both atomic concentration and chemical-specific information at pressures greater than 20 Torr. Using synchrotron X-rays at Lawrence Berkeley Nation Laboratory, the Advanced Light Source has several beamlines dedicated to APXPS endstations that are outfitted with various in situ/operando features such as heating to temperatures > 500 °C, pressures greater than 20 Torr to support solid/liquid experiments and electrical leads to support applying electrical potentials support the ability to collect XPS data of actual electrochemical devices while it's operating in near ambient pressures. This talk will introduce APXPS and provide several interface electrochemistry examples using in situ and operando APXPS, including the probing of Sr segregation on a SOFC electrode to a Pt metal electrode undergoing a water-splitting reaction to generate oxygen, the ability to measure the electrochemical double layer (EDL) to our most recent efforts to directly probe an ion exchange membranes Donnan potential. Gaining new insight to guide the design and control of future electrochemical interfaces and how Bob, electrochemistry, and I have interfaced over the years.
(Invited) Low Temperature PEM Cells Leveraging Hydrogen and Oxygen Evolution Electrodes
Authors: Ayers Katherine E.
Published: November 2022

Proton exchange membrane-based electrochemical devices have been growing in commercial relevance, from fuel cells for automotive and other vehicle applications to hydrogen production and energy storage applications. These membranes are highly versatile, able to operate with both vapor and liquid feed systems, different cation conductors, and with different redox chemistries such as for flow batteries. This talk will focus on electrolyzer advancements in PEM systems and related synergies with flow batteries and CO2 electrolysis, which each share an electrode with water electrolyzers.

Renewable hydrogen generation is a key enabler for decarbonization. The need for a sustainable source of hydrogen has been widely recognized: carbon dioxide re-utilization requires hydrogen to make useful chemicals, and ammonia production is one of the largest industrial demands for hydrogen. Over 95% of hydrogen is currently made from fossil fuels, generating CO2 as a byproduct; this reality needs to change in order to reach sustainability. Currently, the only commercial options for hydrogen production from water are alkaline electrolysis and PEM electrolysis, which will need to be leveraged to make impact in the near term before less mature technologies like solid oxide electrolysis become viable at scale. PEM technology has considerable opportunity for cost reduction and performance improvement, based on many years of research and development in the related PEM fuel cells.

To accelerate this progress in a still emerging market, enlarging the field by working in similar technology areas is helpful. Flow battery research based on hydrogen cells, such as hydrogen halide and hydrogen iron batteries, can validate low catalyst loadings for the hydrogen evolution electrode, and advance coatings for hydrogen embrittlement resistance. Similarly, carbon dioxide electrolysis involves reduction of carbon dioxide on one electrode, but splitting water to evolve oxygen at the other. As another area of research gaining significant interest, CO2 electrolysis can help enable advanced porous transport layer development and oxygen evolution catalyst advancements, and eventually help drive component volumes. In this talk, opportunities and progress benefitting these technologies will be discussed.
Intermediate-Temperature Electrolysis: Electrode Microstructure and Chemistries
Authors: Reese Austin Jerad , Peng Alex J. , Nason Abigail K. , Suntivich Jin
Published: November 2022

Hydrogen from water electrolysis is essential to energy and industrial decarbonization. Beyond being a carbon-neutral fuel to stabilize the intermittent nature of the renewable grid, hydrogen also plays a key role in manufacturing including ammonia and steel production. Intermediate-temperature water electrolysis (>200 °C) has several advantages. First, the thermodynamic requirement for water splitting decreases as temperature increases. Second, reaction kinetics are more facile at higher temperatures. We present water electrolysis using an intermediate-temperature solid acid electrolysis cells (SAECs), with CsH2PO4 (CDP) as an electrolyte. Inspired by Fujiwara et al., whose work demonstrated water electrolysis in SAEC1, we extend upon their work to understand the role of electrode materials on stability and efficiency. We analyze the microstructure of post-electrolysis SAFCs to understand the role of temperature and electrode composition on the degradation. We focus on the reaction kinetics of the oxygen evolution reaction (OER) on the anode and present the challenges that must be overcome by future materials.

(1) Fujiwara, N.; Nagase, H.; Tada, S.; Kikuchi, R. Hydrogen Production by Steam Electrolysis in Solid Acid Electrolysis Cells. ChemSusChem
2021, 14 (1), 417–427. https://doi.org/10.1002/cssc.202002281.
Efficient Prediction of Redox Potentials of First-Row Transition Metal Complexes for Aqueous Redox Targeting Flow Batteries Using Density Functional Theory
Authors: Rahbani Noura , Baudrin Emmanuel , de Silva Piotr
Published: November 2022

Redox targeting flow batteries are an emerging alternative to the traditional redox flow battery architecture which offer improved energy density via an added electroactive solid ‘booster’. For an efficient system, it is imperative that the redox potentials of the soluble redox mediator and the solid match. For this purpose, transition metal complexes are a promising class of redox mediators due to the tunability of their solubility and electrochemical potential, and the ability to take sustainability into account. As such, reliable and time-efficient prediction tools for the redox potentials of transition metal complexes are needed to help with the search for new potential systems. While density functional theory usually provides a good trade-off between computational cost and accuracy, calculations on transition metal complexes often result in large errors. Thus, they have been traditionally used for studying trends of the ligand effect rather than providing accurate predictions. In this communication, we compare redox potential predictions from different solvation methods and levels of theory using an initial experimental data set based on aqueous iron complexes with bidentate ligands. Good predictions (MAE= 0.23 V) are obtained using the COSMO-RS solvation model which is not universally available in DFT software. When using the more common implicit solvation models, there is a general deviation from experimental results, irrespective of the level of theory used. We propose that these errors are conveniently corrected by using simple linear regression using the experimental data as a training set, which yields a good prediction of redox potentials (MAE= 0.09 V). The predictive power of this method is also demonstrated by cross-validation using complexes with different metal centers and ligand types.

Figure 1
(Keynote) Reinventing Batteries through Nanoscience
Authors: Cui Yi
Published: November 2022

The fast growth of portable power sources for transportation and grid-scale stationary storage presents great opportunities for new battery chemistries. How to increase energy density, reduce cost, speed up charging, extend life, enhance safety and reuse/recycle are critical challenges. Here I will present how we utilize nanoscience to reinvent batteries and address many of challenges by understanding the materials and interfaces through new tools and providing new materials guiding principles. The topics to be discussed include: 1) A breakthrough tool of cryogenic electron microscopy, leading to atomic scale resolution of fragile battery materials and interfaces. 2) Materials design to enable high capacity materials: Si and Li metal anodes and S cathodes. 3) Interfacial design with polymer and inorganic coating to enhance cycling efficiency of battery electrodes. 4) New electrolyte design. 5) New battery chemistry for grid scale storage.
(Keynote) Engineering Interfaces for Electrochemical Devices Using Atomic Layer Deposition
Authors: Bent Stacey F.
Published: November 2022

Meeting the world’s growing energy needs sustainably is one of the most important challenges of our time, and electrochemical devices such as fuel cells and batteries will continue to hold a significant place in sustainable energy systems. Due to the central role that interfaces have in electrochemical systems, it is critical to engineer and control these interfaces. This talk will describe our research on layer-by-layer synthetic strategies, namely atomic layer deposition (ALD), to engineer thin film materials used at electrochemical interfaces with a high level of control over composition, structure, and thickness. Both battery and electrocatalysis applications for energy storage and conversion will be described. We use ALD interfacial layers deposited on the copper current collector as a new strategy to control lithium metal morphology and improve electrochemical performance in Li metal batteries. Specifically, TiO2 films deposited by ALD on the current collector of lithium anodes generate a lithiophilic surface layer that enables uniform and reversible Li plating, leading in turn to improvements in battery cyclability. Other metal oxide interfacial layers are also shown to influence lithium morphology and battery performance. Toward electrocatalysis, we show that nanometer thick layers of earth abundant materials deposited by ALD are active for the oxygen evolution reaction (OER), an important reaction in the conversion of sunlight to fuels. Nickel-oxide, nickel-iron-oxide, and nickel-aluminum-oxide films are synthesized with controlled composition by ALD and the promotion of the OER activity by iron and aluminum is explored. The potential of atomic layer deposition to synthesize nanoscale materials and engineer interfaces for electrochemical energy applications will be discussed.
(Invited) Gradient Ni-SDC Anode By Reactive Co-Sputtering for Low Temperature Solid Oxide Fuel Cells
Authors: Kim Taeyoung , Kim Hyong June , GO Dohyun , Shin Jeong woo , Yang Byung Chan , Son Ji-Won , An Jihwan
Published: November 2022

Solid oxide fuel cells (SOFCs) are attracting attention as next-generation energy conversion devices due to their high efficiency, eco-friendliness, and scalability. However, the high operation temperature of conventional SOFCs (> 800°C) has posed several practical issues such as thermal degradation and limited material choice. To overcome this limitation, low-temperature SOFC (LT-SOFC, operation temperature <600°C) is actively being researched these days. Ni-YSZ (nickel-yttria stabilized zirconia) is commonly used as anode material in SOFCs. Ni-YSZ anodes are reasonably conductive at high operating temperatures and stable under harsh reducing conditions. However, at lower operating temperatures, the low conductivity of Ni-YSZ becomes an issue for use as an anode. Using doped ceria instead of YSZ is considered an alternative because the doped ceria has higher conductivity compared to YSZ due to the co-existence of multivalent states, i.e., Ce3+ and Ce4+, which can be further improved by doping. Moreover, if one adopts a carefully designed anode structure, e.g., gradient structure, the electrochemical performance of Ni-doped ceria anode can be further improved. Employing nanoscale components, e.g., thin films, are also one of the strategies to improve the electrode kinetics at the low operating temperature of LT-SOFCs. Thin film electrodes with short electronic and ionic paths as well as high surface area contribute to low ohmic and activation resistances. While high uniformity, reproducibility and throughout are practical concerns in thin film fabrication, reactive sputtering, which can produce uniform ceramic thin films from metal target in reactive gas environment in high reproducibility ad deposition rate, is a suitable candidate for thin film components for SOFCs.

In this study, we fabricate a Ni-Samaria doped ceria(SDC) gradient anode by reactive co-sputtering. We prepare and characterize the cells with homogeneous and gradient-structured Ni-SDC thin film anodes. The gradient Ni-SDC thin film anode is composed of three layers, whose compositions are graded in a way that the Ni content increases from bottom (near electrolyte-anode interface) to top (anode top-surface). Possibly due to the combination of facilitated ionic conduction near electrolyte-anode interface and higher catalytic activity at anode surface, we observe the improved anode kinetics with lower activation resistance in the cell with gradient-structured Ni-SDC anode compared to the one with homogeneous anode.
Pd-Doped Perovskite Oxides with Phase Transition and Bimetallic Nanocatalyst Exsolution to Achieve Highly Active Bifunctional Fuel Electrodes for Reversible Solid Oxide Electrochemical Cells
Authors: Kim Kyeong Joon , Lim Chaesung , Bae Kyung Taek , Lee Jong Jun , Oh Mi Young , Kim Hyung Jun , Kim Hyunmin , Kim Guntae , Shin Tae Ho , Han Jeong Woo , Kim Dongyeon , Lee Kang Taek
Published: November 2022

The reducibility of B-site elements in perovskite (ABO3) structures is one of the important factors that accelerate the in-situ exsolution of metallic nanocatalysts. Herein, a highly catalytically active and durable Pd-doped perovskite-based anode material (La0.6Sr0.4Co0.15Fe0.8-xPdxO3-𝛿 (LSCFP)) was developed for reversible SOCs. Under fuel electrode conditions, the LSCFP material is fully transformed into a stable Ruddlesden-Popper phase decorated with bimetallic Co-Fe nanocatalysts. Highly reducible Pd doping in the perovskite lattice effectively reduces the energy barrier for exsolution and formation of bimetallic catalysts on the electrode surface and promote phase transformation into the stable Ruddlesden-Popper-phase in the reducing atmosphere. The SOC with LSCFP fuel electrode yielded outstanding performances in both fuel cell and electrolysis cell modes at 850 °C, with remarkable reversible-cyclic stability. These results indicate that the novel LSCFP, which can simultaneously perform phase transition and bimetal exsolution under reducing conditions, is a very promising candidate as a bifunctional fuel electrode for reversible SOCs.
Architectural Optimization of Nd2NiO4+
δ- Nd0.5Ce0.5O2-δ Oxygen Electrode for Reversible Solid Oxide Cells
Authors: Akter Ayesha , Grande Hector , Pal Uday , Basu Soumendra , Gopalan Srikanth
Published: November 2022

Electrochemical performance in reversible solid oxide cells is influenced by the microstructure and dimensions of the components and the transport properties of the constituent materials. In this work, we consider oxygen electrodes in the Nd2NiO4+
δ- Nd0.5Ce0.5O2-
δ materials system. Optimization of the oxygen electrodes in this system has been achieved by considering the tradeoffs in the microstructure and dimensions of the active layer and the current collecting layer. Detailed electrochemical analysis of the symmetrical cells using impedance spectroscopy has led us to an optimized architecture with significantly reduced ohmic and polarization resistance. The optimized architecture, based on symmetrical cells, has been translated into single, complete reversible solid oxide cells. Significant performance improvement has been achieved in both fuel cell and electrolysis mode compared to baseline materials and electrode architecture material.
Reactive Sputtered NiO-YSZ Anode Functional Layer for Thin Film Low-Temperature Solid Oxide Fuel Cell
Authors: Kim Hyong June , Kim Taeyoung , Yang Byung Chan , Jo Sung Eun , Son Ji-Won , An Jihwan
Published: November 2022

Solid oxide fuel cell (SOFC) is one of the most promising next-generation electrochemical energy conversion devices because of its wide choice of fuels, cleanliness and, high efficiency of up to 70-85%( with heat utilization). Recently, low-temperature SOFC (< 600 ℃) has been studied to overcome the limitations of conventional SOFC, e.g., thermal stability, cost, and limited application. However, lowering operated temperature is challenging due to slow charge transfer and ion transport rates. Therefore, SOFC design with thin-film stacks, namely thin-film SOFC (TF-SOFC) fabricated on porous anode support, have been usually adopted for sufficient power density even at this temperature regime.

A ceramic-metal composite (cermet) of Ni and YSZ (yttria-stabilized zirconia) is the most common anode or anode functional layer (AFL) material of TF-SOFC, because Ni-YSZ cermet has reasonable cost, chemical stability in a reducing atmosphere at high temperature, and similar thermal expansion coefficient to that of YSZ electrolyte. Various thin-film techniques have been reported for AFL fabrication, e.g., pulsed laser deposition (PLD), RF sputtering, etc. Among those, reactive sputtering method, which uses metal target in controlled gas conditions (e.g., oxygen condition for oxide deposition), is a versatile method to deposit various types of thin films with fast deposition speed (up to > 1um/hr), which is beneficial in manufacturability regarding the usual thickness range of AFL (a few microns).

In this study, therefore, we studied physical and chemical properties of nanocomposite Ni-YSZ films fabricated by using the reactive sputtering deposition technique, focusing on the effect of sputter parameters. In particular, Oxygen partial pressure significantly affects deposition speed, surface morphology, composition, electrochemical performance, and thermal durability at 450 ℃. It is shown that excessive O2/Ar partial pressure ratio (> 0.2) significantly reduces the deposition speed by approximately one order of magnitude compared to the lower ratio case. In morphological analysis, O2/Ar partial pressure ratio affect nano-structured of anode, after annealing process at 1200℃ with air. Also, the Ni-YSZ anode sputtered at the environment of O2/Ar partial pressure ratio of 0.1 sample shows the lowest activation resistance when applied to LT-SOFC’s anode. The O2/Ar 0.5 sample shows surface Ni agglomeration due to high NiO-to-metallic Ni ratio.
On-Board Strontium Getters for Improved Solid Oxide Cell Durability
Authors: Zhang Yubo , Wen Yeting , Huang Kevin , Nicholas Jason
Published: November 2022

Nano-composite electrodes fabricated by introducing nano-sized mixed ionic and electronic conducting (MIEC) catalysts into partially-sintered micro-sized ionic conducting backbones have been used by many researchers to improve the electrochemical performance, and/or reduce the operating temperature, of Solid Oxide Cells (SOCs).1 Unfortunately, these infiltrated electrodes have often possessed poor electrochemical performance stability.2

This presentation will review recent results showing how pre-infiltrated ceria nano-particles3 or atomic layer deposited zirconia overcoats4 can be used as on-board Sr getters to increase the long-term stability of La0.6Sr0.4Co0.8Fe0.2O3-x (LSCF)-infiltrated Ce0.9Gd0.1O1.95-x (GDC) SOC electrodes, without compromising initial performance. This talk will also present results showing that when combined, these surface modification techniques result in LSCF-GDC performance degradation rates that are no better than those obtained from each technique used separately. Lastly, this talk will present GDC pre-infiltration results supporting a newly-emerging consensus that Sr does not surface segregate in Sm0.5Sr0.5CoO3-x (SSC) like it does in LSCF.

References

D. Ding, X. X. Li, S. Y. Lai, K. Gerdes and M. L. Liu, Energy Environ. Sci., 7, 552 (2014).

M. Shah, P. W. Voorhees and S. A. Barnett, Solid State Ionics, 187, 64 (2011).

Y. Zhang and J. D. Nicholas, Journal of the Electrochemical Society, 168, 024522 (2021).

Y. Zhang, Y. Wen, K. Huang and J. D. Nicholas, ACS Applied Energy Materials, 3, 4057 (2020).
Precatalyst Reconstruction during the Electrocatlytic Oxygen Evolution Reaction: The Influence of the Precursor and the Transformation Conditions
Authors: Hausmann Jan Niklas , Mebs Stefan , Laun Konstantin , Zebger Ingo , Driess Matthias , Menezes Prashanth W.
Published: November 2022

The oxygen evolution reaction (OER) is the most likely reaction to supply electrons and protons for future green fuel and chemical formation, and thus many materials have been studied for their suitability as OER (pre)catalysts. However, in-situ and post-catalytic studies have shown that the harsh OER conditions alter the electrode materials, causing a reconstruction to mainly transition metal oxyhydroxides in alkaline and near-neutral electrolyte. As this reconstructed phase is the real catalyst, its atomic structure and physical properties must be precisely known. These properties will be affected by the precatalyst and the reconstruction conditions, like the product of a chemical reaction is affected by the substrate and reaction conditions. For the elucidation of such reconstruction processes, a broad range of spectroscopic (in-situ) methods combined with new, meaningful precursors are required.

Herein, investigations on the reconstruction of several precatalysts such as phosphites,1 borophosphates,2 selenites,3 silicides,4 and elemental metal foams are presented. These reconstructions were analysed by in situ Raman and X-ray absorption spectroscopy together with state-of-the-art post-mortem characterization techniques. In an effort to connect this data, we propose ideas relating the precatalyst structure with the one of the formed oxyhydroxides. Additionally, we critically debate the question: why should a non-oxyhydroxide phase be used for the OER if it will anyway reconstruct? Moreover, as mentioned, also the reconstruction conditions affect the specific nature of the formed oxyhydroxide. Considering this, we present a case, where from the same precatalyst, catalysts with entirely different structural and electrocatalytic properties were obtained by only changing the electrochemical reconstruction conditions (potential, pH, electrolyte composition...).

References:

Menezes, P. W. et al. A structurally versatile nickel phosphite acting as a robust bifunctional electrocatalyst for overall water splitting. Energy Environ. Sci.
11, 0–13 (2018).

Menezes, P. W. et al. Helical cobalt borophosphates to master durable overall water-splitting. Energy Environ. Sci.
12, 988–999 (2019).

Hausmann, J. N. et al. Understanding the formation of bulk- and surface-active layered (oxy)hydroxides for water oxidation starting from a cobalt selenite precursor. Energy Environ. Sci.
13, 3607–3619 (2020).

Hausmann, J. N. et al. Evolving Highly Active Oxidic Iron(III) Phase from Corrosion of Intermetallic Iron Silicide to Master Efficient Electrocatalytic Water Oxidation and Selective Oxygenation of 5‐Hydroxymethylfurfural. Adv. Mater.
33, 2008823 (2021).

Figure 1