bluuebunny/crossref_metadata_2025_split huggingface dataset:
(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) 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.
(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.
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.
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
(Invited) Resolving a Catalytic Mechanism on an Electrode Surface: Using Time Resolution to Identify Theoretical Descriptors
Authors: Cuk Tanja 
Published: November 2022

Catalytic mechanisms at electrode surfaces guide the development of electrochemically controlled energy storing reactions and chemical synthesis. The intermediate steps of these mechanisms are challenging to identify experimentally but are critical to understanding the speed, stability, and selectivity of product evolution for a given energy input. One of the most studied reactions is the water-splitting reaction which breaks apart H2O into H2 and O2. In the laboratory group, we employ time-resolved optical and vibrational spectroscopy to deconstruct the energy intensive part, the oxygen evolution reaction (OER), into its component parts. The first step of this oxidative reaction, which is to release a proton and take an electron from water, has often been thought of as a theoretical “descriptor” that differentiates the OER activity of materials: if this is hard to do, then the material is less energy efficient and if it is easy to do, then a later, bond-forming step limits the energy efficiency. Yet, the formation free energy of this step had yet to be measured experimentally. Here, I will begin by summarizing the work done previously by the group: the structure and kinetics of forming these first reaction intermediates (Ti-OH*) by their optical and vibrational signatures upon driving OER with an ultrafast photo-trigger of the electrode surface (SrTiO3). I will then discuss the most recent work, which shows that by separating the reaction steps in time and optically detecting these intermediates created upon hole-transfer from the valence band, we can determine their formation free energy1. In addition to the optical spectroscopy, we employ reaction isotherm methodology borrowed from surface studies of reactions. By tuning the pH, we obtain a Langmuir isotherm on the driven surface (Figure 1) regulated by the proton transfer that increases surface hydroxylation for higher pH prior to photo-triggering OER. From the midpoint of this isotherm, one can obtain the formation free energy of Ti-OH* from valence band holes. Such an application of isotherms is new in that the product is not the final one, for which one generally knows the reaction free energy, but rather an intermediate of a reaction. Overall, the innovation of the work is to utilize kinetic measurements to obtain the calculated free energy of an intermediate reaction step at a material surface.

1I. Vinogradov, S. Singh, H. Lyle, M. Paolino, A. Mandal*, J. Rossmeisl, T. Cuk
*,
Nature Materials, 2022, 21, 88.
Figure 1: The time-resolved optical data as a function of pH show how the population of intermediates generates a reaction isotherm (black trace). The emission (in blue) counts the intermediate Ti-OH* population.

Figure 1
The Effect of Photoanode Interface and Surface Treatment in Dye-Sensitized Photo-Electrochemical Systems for Effective Lignin Decomposition
Authors: Kang Hyeong Cheol , Kim Saerona , Yoo Kicheon , Leem Gyu , Lee Jae-Joon 
Published: November 2022

Traditionally, Dye-sensitized photo electrochemical cells (DSPECs) have been targeted for solar-driven water splitting as production of fuels in aqueous media. Recently, hydrogen atom transfer incorporated dye-sensitized photo electrochemical cell (HAT-DSPEC) which used photocatalyst and homogeneous catalysts incorporating system was suggested for the decomposition process of lignin. This HAT-DSPEC system representing conversion efficiencies over 90% resulted in the formation of the oxidized ketone product from model compounds under simulated solar illumination with an applied bias 0.4 V vs Ag/Ag+
for 24 hrs. However, they have several issues such as long reaction time, low stability, and high bias potential.
To overcome these problems, in this study, dye-sensitized photovoltaics’ advanced technic is applied. In HAT-DSPEC system, photo-anode (TiO2@Dye) has important role to produce oxoammonium species by oxidizing nitroxyl derivatives, such as 4-acetomido TEMPO (ACT). And these oxoammonium species act as a catalytic reaction with lignin model compounds (LMCs) to oxidizing of 1o or 2o alcohol and cleavage Caryl-Cα bond cleavage. However, in photo-anode, lots of charge recombination and electron back transfer occurs on the FTO and TiO2 surface and it induce low current and reactivity. For effectively producing oxoammonium species from photoelectrode, using blocking layer to passivate FTO surface from electrolytes and applying TiCl4 post-treatment for fast charge transport in TiO2 by enhancing interconnection of TiO2 nanoparticles. The photocurrent response of the m-TiO2@Ru470 photoelectrode in a nonaqueous electrolyte was examined with increasing mediator concentration during light on/off cycles under AM 1.5G illumination (100 mW/cm2), with an applied bias 0.1 V vs Ag/Ag+. Three kinds of electrode condition such as m-TiO2, BL/m-TiO2, BL/m-TiO2/TiCl4 post treatment was examined under same condition and treated photoelectrode (BL/m-TiO2/TiCl4) showed a significant increase in maximum photocurrent up to approximately 367.69 μA/cm2 with 3 mM ACT mediator, while BL/m-TiO2 exhibits 26.75 μA/cm2 and m-TiO2 1.26 μA/cm2. This result indicates that the blocking layer and TiCl4 post treatment enhanced electron lifetime and collection efficiency in the photoelectrode, as well as enhancing the capability of producing oxoammonium species.
Synthesized Pectin from Food Waste and Its Application in Electrolyte Gelation for CO2 Reduction
Authors: Wilson Nathan W. , Botte Gerardine G. 
Published: November 2022

The utilization of in-situ resources such as food waste or plants grown on Mars combined with the available Martian regolith and atmosphere presents a path towards battery separators with increased sustainability, energy density, and durability. Separators that focus on CO2 reduction take advantage of both a highly relevant source of materials on Mars and a solution to an increasingly relevant problem of the increase of atmospheric CO2 on Earth.
In this paper we evaluate the electrochemical and thermal properties of gel electrolytes synthesized from food waste and their performance in CO2 reduction. Our work focuses on the extraction of pectins from soybean hull and tomato pomace as sources of inedible biomass. Cross-linking and ionic activity of the pectin-based gel electrolytes are determined by the integration of monovalent and divalent cations. A biomass-based polymer electrolyte provides a novel method of using in-situ resources for chemical conversion and energy storage that is critical for long-term space travel.