bluuebunny/crossref_metadata_2025 huggingface dataset:
Green Hydrogen Production Using Manganese – Vanadium Redox Flow Batteries
Authors: Chaurasia Shabdiki B. , Aravamuthan Sundar Rajan , Sullivan Connor S. , Ross Michael B. , Agar Ertan
Published: August 2024

The redox flow batteries (RFBs) can be tuned to allow mining of surplus energy capacity and supplement green hydrogen economy as a one-stop station [1, 2].With this concept, an RFB can undergo two sequential discharging modes: i) electrochemical discharge of redox active species, and ii) chemical discharge to produce hydrogen gas, when surplus electricity is available, on the surface of electrocatalysts contained in additional external tanks (i.e., dual circuit RFB) [3, 4]. Herein, electrolytes with Mn3+/Mn2+ (RFB catholyte ~ 1.5 V vs. SHE) and V3+/V2+ (RFB anolyte ~ −0.26 V vs. SHE) redox species are flown to spatially separated external catalytic reactors to drive redox mediated water electrolysis. The fully charged V2+ redox mediator in the anolyte provides electrons to achieve hydrogen evolution reaction (HER) and thereby itself gets discharged to V3+ redox state before circulating back to flow battery tanks.

Considering the additional layer of redox-mediated water electrolysis, it is imperative to identify benchmark cycling performance for a robust dual circuit RFB operation. In the first phase of our study, electrochemical behavior of Mn3+/Mn2+ redox couple in the favorable presence of V5+ as an additive was elucidated using ultramicroelectrode voltammograms. Despite significant performance enhancement, capacity fade during galvanostatic cycling could not be fully eliminated owing to Mn3+ disproportionation reaction and manganese crossover. Also, charge/discharge cycling profiles suggest that the inevitable Mn3+ disproportionation affects the true state-of-charge in electrolytes which in turn hinders their potential to generate hydrogen gas. Working towards hydrogen generation, our recent efforts have been to evaluate kinetics for hydrogen evolution reaction (HER) on different carbon substrate – electrocatalyst combinations in acidic V3+/V2+ environment. Overall, this study aims to provide a profound understanding of reliable operating conditions to establish a synergy between Mn3+ disproportionation during the conventional energy storage mode and the total volume of hydrogen gas produced during the secondary mode.

References

Reynard, D. and H. Girault, Combined hydrogen production and electricity storage using a vanadium-manganese redox dual-flow battery. Cell Reports Physical Science, 2021. 2(9): p. 100556.

Amstutz, V., et al., Renewable hydrogen generation from a dual-circuit redox flow battery. Energy & Environmental Science, 2014. 7(7): p. 2350-2358.

Peljo, P., et al., All-vanadium dual circuit redox flow battery for renewable hydrogen generation and desulfurisation. Green Chemistry, 2016. 18(6): p. 1785-1797.

Piwek, J., et al., Vanadium-oxygen cell for positive electrolyte discharge in dual-circuit vanadium redox flow battery. Journal of Power Sources, 2019. 439: p. 227075.
(Invited) Intermetallics Based on Sodium Chalcogenides Promote Stable Electrodeposition – Electrodissolution of Sodium Metal Anodes
Authors: Mitlin David
Published: August 2024

Sodiophilic micro-composite films of sodium-chalcogenide intermetallics (Na2Te and Na2S) and Cu particles are fabricated onto commercial copper foam current collectors (Na2Te@CF and Na2S@CF). For the first time a controllable capacity thermal infusion process is demonstrated. Enhanced wetting by the metal electrodeposition leads to state-of-the-art electrochemical performance. For example, Na2Te@CF-based half-cells demonstrate stable cycling at 6 mA cm-2 and 6 mAh cm-2, corresponding to 54 μm of Na electrodeposited/electrodissolved by geometric area. Sodium metal battery (SMB, NMB) cells with Na3V2(PO4)3 (NVP) cathodes are stable at 30C (7 mA cm-2) and for 10,000 cycles at 5C and 10C. Cross-sectional cryogenic focused ion beam (cryo-FIB) microscopy details deposited and remnant dissolved microstructures. Sodium metal deposited onto Na2Te@CF is dense, smooth, and free of dendrites or pores. On unmodified copper foam, sodium grows in a filament-like manner, not requiring cycling to achieve this geometry. Substrate-metal interaction critically affects the metal-electrolyte interface, namely the thickness and morphology of the solid electrolyte interphase (SEI). Density functional theory (DFT) and mesoscale simulations provide insight into support-adatom energetics, nucleation response, and early-stage morphological evolution. On Na2Te sodium atomic dispersion is thermodynamically more stable than isolated clusters, leading to conformal adatom coverage of the surface.
Stable Cycling of Ultrahigh Mass Loaded MnO2 for Low-Cost Sodium-Ion Batteries
Authors: Luo Yunkai , Chandrasekaran Swetha , Hu Bintao , Freyman Megan C. , Lin Dun , Li Yat , Worsley Marcus Andre , Dunn Bruce S.
Published: August 2024

Achieving cost-effective and sustainable solutions for large-scale energy storage is critical for advancing the global clean energy transition. The intermittent nature of green energy underscores the inadequacy of current large scale energy storage technologies like pumped hydroelectricity which is susceptible to geographic and water resource constraints, making batteries a prime candidate for this role. Although lithium-ion batteries (LIBs) with high energy and power density are a viable solution, the high cost and uneven distribution of lithium reserves limits the widespread application of LIBs for grid energy storage. Considering these developments and the challenges posed by limited lithium reserves, sustainable and low-cost sodium-ion batteries (SIBs) emerge as a promising alternative.

Among the various battery electrode materials, manganese dioxide (MnO2) stands out as a promising choice for large-scale energy storage applications due to its earth abundance, cost-effectiveness and non-toxic nature. Although MnO2 is known as a pseudocapacitive material with superior cycling stability in aqueous electrolytes, its dissolution in non-aqueous electrolytes has restricted its widespread use in long lifetime batteries. In this study, we demonstrate that an ether-based electrolyte solution (1M NaClO4 in diglyme) is able to achieve stable cycling of electrodeposited ε-MnO2 as a cathode for SIBs, reaching a over 75% capacity retention over 1000 cycles. This response surpasses conventional ester-based electrolytes (58% of 1M NaClO4 in EC/PC). A comparative cycling stability study, coupled with electrochemical quartz crystal microbalance characterization, validates the efficacy of the ether-based electrolyte in mitigating MnO2 dissolution. Furthermore, the integration of 3D printed graphene aerogel (3D GA) as a scaffold for electrodeposited MnO2 leads to enhanced electrochemical performance of the MnO2 electrode (3D MnO2/GA), resulting in a high areal capacity of 4.4 mAh cm-2 at a current density of 10 mA cm-2. The 3D MnO2/GA electrode possesses scalable electrochemical performance with mass loadings from 20 mg cm-2 to 80 mg cm-2. Using this electrode, a high mass loaded sodium-ion battery (SIB) device was fabricated by using utilizing 58 mg cm-2 3D MnO2/GA as the cathode and 16 mg cm-2 dip-coated TiO2@Cu foam as the anode. This MnO2 | TiO2 device delivered a notable areal capacity of 6.2 mWh cm-2 and a high areal power density of 70.7 mW cm-2. Moreover, the SIB device demonstrates 85% capacity retention after 500 cycles, underscoring the stable cycling of this high-energy and power-density SIB device.
High Entropy Alloys as Bifunctional Catalysts for Reversable Metal Air Batteries
Authors: Stalcup Matt , Percival Stephen J.
Published: August 2024

The development of stable non-noble metal bifunctional catalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are essential for technologies such as reversible metal air batteries. We have shown that synthesis of high entropy alloy nanoparticles formed through a novel synthesis method where metal precursor containing aqueous nanodroplets freely diffusing in an emulsion solution, collide with an electrode surface and the metal precursors are reduced, thus forming a homogeneous particle containing the predetermined metal composition. Afterwards, the particles are annealed at a low temperature causing a phase separation of the metals, forming a metal nanoparticle that is surrounded by a stabilizing metal oxide. We have demonstrated that equimolar Fe, Ni, Co, Cr, and Mn solutions produce bifunctional FeNiCo metal nanoparticles surrounded by CrMnOx that are very active for both OER and ORR. The synthesis technique also affords the flexibility to tailor composition of the nanoparticles and potentially provide access to previously difficult to synthesize compositions and may alter the electrocatalytic reaction pathways and activities.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525
Amorphous Cobalt Tin Oxide/Reduced Graphene Oxide Decorated on Graphite Felt as Positive Electrode for Vanadium Redox Flow Battery
Authors: Huang Zih-Jhong , Lin Hsin-Te , Kabtamu Daniel Manaye , Wang Chen-Hao
Published: August 2024

The Vanadium Redox Flow Battery (VRFB) stands out as one of the most promising large-scale energy storage systems. Nevertheless, the graphite electrode materials commonly used in VRFBs often exhibit drawbacks such as limited electrochemical activity and insufficient conductivity, ultimately resulting in suboptimal performance for the VRFB. In this study, we utilized highly conductive reduced graphene oxide (rGO) as a carrier for cobalt tin oxide (CoSnO3), aiming to enhance their catalytic capability towards vanadium ions. CoSnO3/rGO composite was confirmed using XRD and TEM, revealing nanoboxes morphology and amorphous structure. XPS and EPR analysis showed an increase in oxygen vacancies after composite formation.

In order to further prove the effect of CoSnO3/rGO composite catalyst modified graphite felt, the modified graphite felt electrode was applied to the positive electrodes of VRFB, and the charge and discharge tests at different current densities were carried out. At a current density of 160 mA/cm², the composite demonstrated a voltage efficiency of 74.22%, surpassing the heat treated graphite felt by 2.69%. Noteworthy enhancements in capacitance were also evident at this specific current density. Furthermore, stability testing over 50 cycles revealed no significant degradation, underscoring the superior performance and outstanding durability of the CoSnO3-rGO modified graphite felt throughout charge and discharge cycling. The result of this study highlight the promising potential of CoSnO3-rGO composites as efficient catalysts for vanadium redox flow batteries, providing improvements in electrochemical performance and long-term stability.
Design and Synthesis of K-Ion Solid Electrolytes Based on Antiperovskites and Chalcogenides
Authors: Wu Yiying
Published: August 2024

Potassium batteries with organic liquid electrolytes, including K-ion, K–O2, and K–S batteries, have emerged as promising candidates for large-scale energy storage due to the high earth abundance and low redox potential of potassium (−2.93 V versus SHE). However, the issues brought by using liquid electrolyte still hinder the development of K-batteries. The utilization of solid electrolytes will not only have the commonly recognized benefits in suppressing dendritic metal plating and enhancing battery safety, but also in blocking oxygen or sulfur crossover from the cathode. In this presentation, I will present our recent progress in developing K-ion solid electrolytes based on antiperovskites, K3OX (X=Cl, Br and I) and chalcogenides (K3SbS4 and K3SbSe4). Among them, K2.92Sb0.92W0.08S4 exhibits high conductivity of 1.4×10−4 S cm−1 at 40 °C, which is among the best reported potassium-ion conductors at ambient temperature.Their applications in room-temperature K-S and K-O2 batteries have been successfully demonstrated.
Ionic Polybenzimidazoles Crosslinked through Thiol-Ene Reactions for Anion Exchange Membranes
Authors: Abdi Zelalem Gudeta
Published: August 2024

This research introduces a study outlining the synthesis and characteristics of innovative anion exchange membranes that utilize m-polybenzimidazole (m-PBI) as the polymer backbone structure. These membranes incorporate quaternary ammonium groups and alkene groups as side chains. These ionic m-PBI membranes were further crosslinked through thermal thiol-ene reactions. By adeptly manipulating the quantities of attached quaternary ammonium groups and alkene groups, the ion exchange capacity (IEC) values and crosslinking degrees were independently controlled. A comprehensive range of m-PBI based anion exchange membranes was developed, showcasing IEC values ranging from 1.51 to 2.50 mmol/g. This series of membranes demonstrated hydroxide conductivity levels ranging between 14 and 58 mS/cm at an operational temperature of 80 °C. Particularly noteworthy is the comparison between membranes with similar IEC values: the crosslinked membranes exhibited reduced water absorption while effectively maintaining a level of hydroxide conductivity comparable to that of uncrosslinked membranes. Moreover, the crosslinked membranes exhibited enhanced dimensional stability. An intriguing finding emerged from a crosslinked membrane with an IEC value of 2.46 mmol/g, which retained a remarkable 84% of its original hydroxide conductivity after being immersed in a 1.0 M sodium hydroxide solution at 60 °C for a duration of 720 hours. These membranes demonstrated mechanical strength even in their hydrated state, exhibiting tensile strengths ranging from 10.8 to 14.6 MPa. Given their heightened hydroxide conductivity, improved resistance to alkaline conditions, and favorable mechanical attributes, the crosslinked ionic m-PBIs emerge as promising candidates for anion exchange membranes in fuel cell applications.

Keywords

; anion exchange membranes, crosslinking reaction, polybenzimidazole, back titration, mechanical strength.
Direct Hydroquinone Fuel Cells
Authors: Elbaz Lior , Yurko Yan
Published: August 2024

The Increasing interest and need to shift to sustainable energy give rise to the utilization of fuel cell technologies in various applications. The challenging task of hydrogen storage and transport led to the development of liquid hydrogen carriers (LHC) as fuels for direct LHC fuel cells, such as methanol in direct methanol fuel cells (DMFC). Although simpler to handle, most direct LHC fuel cells suffer from durability and price issues, derived from high catalysts’ loadings and by-products of the oxidation reaction of the fuel. Herein, we report on the development of direct hydroquinone fuel cells (DQFC) based on anthraquinone-2,7-disulfonic acid (AQDS) as an LHC. We have shown that DQFC can operate with continues flow of quinone as a hydrogen carrier, outperforming the incumbent state-of-the-art DMFC by a factor of three in peak power density, while completely removing the need for any catalyst at the anode. In addition, we demonstrate that the quinone can be charged with protons in the same system, making it a reversible fuel cell system. We optimized the operating conditions and will discuss the governing conditions to reach best performance.
(Invited) Fluorinated Linear Carbonate Electrolyte for Lithium-Ion Batteries with Fast-Charging, High Voltage, and Wide Operating Temperatures
Authors: Tan Sha , Yen Dean , Hu Enyuan
Published: August 2024

Lithium-ion batteries (LIBs) are key solutions to clean energy. Their high energy densities have led to the dominance of LIBs in mobile devices and electric vehicles. However, traditional electrolyte limits their operation at high voltage and extreme environmental temperatures. Here, we designed a new multifunctional electrolyte, in which lithium bis(fluorosulfonyl)imide (LiFSI) is used as salt and fluorinated diethyl carbonate (DFDEC) is used as the major solvent. With this optimized electrolyte, the graphite||LiNi0.8Mn0.1Co0.1O2 (NMC811) full cells are capable of fast-charging and can deliver long-term cycling with a cutoff voltage as high as 4.5V. Specifically, the battery shows the capacity retention of 84.3% after 500 cycles with an average coulombic efficiency (CE) as high as 99.93%. Synchrotron-based characterization suggests the formation of anion derived, LiF-rich interphases on the surfaces of both graphite anode and NMC811 cathode. Thanks to the fast ion transport and stable interphase, the cell in the optimized electrolyte demonstrates stable cycling behavior within a wide operating temperature. At high temperature (60 ºC), the full cell delivers 88.8% of its initial capacity after 130 cycles at a high current density of 1C. At low temperature (-20 ºC), the optimized electrolyte enables a capacity retention of 90.9% after 100 cycles when charging and discharging at 0.2C.

Acknowledgment: The work done at Brookhaven National Laboratory was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Vehicle Technology Office of the U.S. DOE through Applied Battery Research for Transportation (ABRT) program under contract no. DE-SC0012704. The electrodes used in this study were produced at the U.S. Department of Energy’s (DOE) CAMP (Cell Analysis, Modeling and Prototyping) Facility, Argonne National Laboratory. The CAMP Facility is fully supported by the DOE Vehicle Technologies Office (VTO). This research used beamline 7-ID-2 (SST-2) of the National Synchrotron Light Source II, U.S. DOE Office of Science User Facilities, operated for the DOE Office of Science by Brookhaven National Laboratory under contract number DE-SC0012704. SEM measurements for this manuscript were performed at Center for Functional Nanomaterials, a U.S. DOE office of Science User Facility, at Brookhaven National Laboratory under the contract number DE-SC0012704.
Balancing Activity and Stability through Compositional Engineering of ORR Catalysts
Authors: Khalakhan Ivan , Briega Martos Valentin , Xie Xianxian , Cherevko Serhiy , Matolínová Iva
Published: August 2024

Widespread adoption of advanced energy technologies, such as proton-exchange membrane fuel cells (PEMFCs), relies on the development of efficient and durable electrocatalysts for the oxygen reduction reaction (ORR). Given its unique properties, platinum has been the exclusive option for meeting activity demands, whether in its monometallic form or various bimetallic alloys with other metals1. Nevertheless, the challenge persists with durability due to catalyst degradation under the hostile electrochemical environment of the PEMFC cathode, leading to an irreversible detrimental effect on fuel cell performance. Studies of the degradation mechanisms of ORR catalysts and their underlying principles have highlighted that, among various degradation mechanisms, inhibiting the dissolution of Pt is crucial for suppressing their deterioration2.

Owing to its high oxidation potential, gold has attracted increasing attention as an element that can be utilized to stabilize Pt and Pt-based ORR catalysts3. However, as Au is inactive towards ORR, achieving a balance between catalyst activity and stability requires precise compositional engineering.

Targeting that aim, varying amounts of Au were added to model Pt and PtNi catalysts prepared by magnetron co-sputtering. A systematic study, employing multiple complementary characterization techniques such as Synchrotron Radiation Photoelectron Spectroscopy (SRPES), X-ray Diffraction (XRD), Rotation Disc Electrode (RDE), Scanning Flow Cell coupled to an Inductively Coupled Mass Spectrometer (SFC-ICP-MS), enabled us to gain a comprehensive understanding of the composition–activity–stability relationship to find optimal Pt–Au and PtNi-Au alloying for maintaining high ORR activity and improving catalyst stability4.

References:

(1) Nørskov, J. K.; Rossmeisl, J.; Logadottir, A.; Lindqvist, L.; Kitchin, J. R.; Bligaard, T.; Jónsson, H. Origin of the Overpotential for Oxygen Reduction at a Fuel-Cell Cathode. J. Phys. Chem. B
2004, 108 (46), 17886–17892.

(2) Bogar, M.; Yakovlev, Y.; Sandbeck, D. J. S.; Cherevko, S.; Matolínová, I.; Amenitsch, H.; Khalakhan, I. Interplay Among Dealloying, Ostwald Ripening, and Coalescence in PtXNi100–X Bimetallic Alloys under Fuel-Cell-Related Conditions. ACS Catal.
2021, 11 (18), 11360–11370.

(3) Lopes, P. P.; Li, D.; Lv, H.; Wang, C.; Tripkovic, D.; Zhu, Y.; Schimmenti, R.; Daimon, H.; Kang, Y.; Snyder, J.; et al. Eliminating Dissolution of Platinum-Based Electrocatalysts at the Atomic Scale. Nat. Mater.
2020, 19 (11), 1207–1214.

(4) Xie, X.; Briega-Martos, V.; Farris, R.; Dopita, M.; Vorokhta, M.; Skála, T.; Matolínová, I.; Neyman, K. M.; Cherevko, S.; Khalakhan, I. Optimal Pt–Au Alloying for Efficient and Stable Oxygen Reduction Reaction Catalysts. ACS Appl. Mater. Interfaces
2023, 15 (1), 1192–1200.
Effect of Dispersion Media Composition on the Structure and Rheology of the Short-Sidechain Perfluorosulfonic Acid Ionomer Dispersions
Authors: Khandavalli Sunilkumar , Park Jaehyung , Winter H Henning , Myers Deborah J. , Ulsh Michael , Mauger Scott A
Published: August 2024

Perflourosulfonic acid (PFSA) ionomers are used in many applications including polymer-electrolyte membrane fuel cells and electrolysers owing to their many attractive properties such as excellent ion-conductivity, chemical resistance, mechanical properties, and thermal stability. In polymer-electrolyte membrane fuel cells and electrolysers, they are used as the membrane and as a component in the catalyst layers, to provide proton conductivity and serve as a binder for the catalyst particles, which are two key components of these devices. Understanding the structure and rheological properties of the ionomer dispersions is important for solution-processed fabrication of the membranes and the catalyst layers, and will enable better control their final structure/morphology, and improve the device performance. A water-alcohol solvent mixture is a common dispersion media for ionomer dispersions as well as the catalyst inks. While significant efforts exist on the structure of ionomer dispersions in water-alcohol solvent mixtures, their rheological properties, particularly the effect of solvent composition at non-dilute concentrations remain less explored. In this talk, the effect of water-alcohol (isopropanol) composition of the dispersion media on the rheological properties of ionomer dispersions will be presented. The results of small-angle x-ray scattering characterization of the ionomer dispersions will be also discussed. As a model ionomer, a short sidechain perfluorinated ionomer (PFSA), produced by 3M, was used. In dispersions with low ionomer concentrations, the zero-shear viscosity scaling with concentration was found to be similar for all alcohol fractions in the solvent mixture, following Fuoss’s law for polyelectrolytes. Whereas at higher concentrations, beyond the semi-dilute unentangled regime, their scaling was strongly dependent on alcohol fraction, where the scaling exponent increasing with increasing the alcohol fraction. Furthermore, the dispersions showed dramatic shear-thickening and strain-stiffening behaviors at higher alcohol fractions. The rheological observations suggest water-alcohol composition significantly alters the interactions between ionomer, and consequently their structure, and has strong implications in processing as well as on the morphology/structure of the membranes and the catalyst layers.
Simplified Ftacv Model to Quantify the Electrochemically Active Sitedensity in PGM-Free ORR Catalysts
Authors: Friedman Ariel , Elbaz Lior
Published: August 2024

The development of platinum group metal-free catalysts is considered the most prominent path for reducing the

cost of low-temperature fuel cells (LTFC). Despite the great advancement in the field, its further progress is

currently limited by the ability to understand and mitigate the catalysts’ degradation mechanisms, which up to

recent years was limited by the lack of activity descriptors. Recent work showed that this could be solved using

Fourier-transformed alternating current voltammetry that enables to deconvolute Faradaic currents arising from

the redox reaction of the active sites from the capacitive currents, and by that accurately measure the electrochemically

active site density of these catalysts in situ fuel cells. However, the analysis of the results can be

complex, requiring simulation software for accurate parameter extraction. Herein, a simplified analysis of

Fourier-transformed alternating current voltammetry is presented. This was done by mapping the influence of

various variables, such as resistivity, capacitance, and thermodynamic and kinetic dispersion, on the accuracy of

electrochemically active site density measurements. Under specific, yet realistic, operating conditions, a single

equation with the peak current of the 5th harmonic as the only variable can be used to quantify electrochemically

active site density with high accuracy. This approach was demonstrated using molecular catalysts, iron phthalocyanine,

as a model molecule, and a commercial, heat-treated catalyst.
Surface-Dominated Potassium Storage Enabled by Single-Atomic Sulfur for High-Performance K-Ion Battery Anodes
Authors: Yang Guo-Zhan , Li Wen-Jia
Published: August 2024

Due to the large size and heavy mass of the K-ion, the pursuit of reliable anodes with outstanding comprehensive performance for K-ion batteries (KIBs) remains a formidable challenge. Typically, high-capacity potassium storage will lead to the electrodes’ serious volumetric expansion and elevated instability. Herein, it is identified that a single-atomic sulfur composite can act as a high-performance KIB anode with an excellent combination of capacity, cyclability, and rate. A high content (∼32 wt%) single-atomic sulfur can be covalently bonded into the carbon lattice of multi-shelled hollow nanospheres via a simple low-temperature pyrolyzation of the selected precursor. The superb redox reactivity of the single-atomic sulfur together with the porous architectures for the resultant S/C composite can not only enable a fast surface-dominated potassium storage but also ensure its structural resilience, thereby achieving high specific capacity together with outstanding rate and impressive cyclability. This study envisions new perspectives on designing high-performance sulfur-based electrodes.
A Comparative Effect of CsH2PO4/ZrP2O7 Composite Electrolytes for Intermediate Temperature Fuel Cell
Authors: Veer Dharm , Singh Deshraj , Katiyar Ram S
Published: August 2024

Solid acid composite CsH2PO4 (CDP)/ZrP2O7 were synthesized and characterised with different weight ratio of CDP, SDP and ZrO2. The characterisations of the Solid acid composite were observed the structural, thermal stability and conductivity in terms of X-ray diffraction (XRD) analysis, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis, Differential Thermal Analysis, and conductivity measurements. The amount of CDP and ZrP2O7 powder were used for pallet production. The composites powders were to form of pellets of 1mm thickness for conductivity measurement. ZrP2O7 in the composites has a large effect on the conductivity measurement and this material increased the temperature and time dependent conductivity of CDP by up to 4 orders of magnitude. The transition was identified in CDP/ZrP2O7 composites under atmospheric pressure. The thermal stability of the solid acid composites for dehydration, melting, and decomposition was investigated in the temperature range of 50 to 300 °C under environments with atmospheric humidification.

Keywords: Composite Electrolytes, Conductivity, Thermal Analysis, Caesium Dihydrogen Phosphate, Pyrophosphates.
(Digital Presentation) The Effect of Coating Quality on Water Transport in the Gas Diffusion Layer of PEM Fuel Cells
Authors: Herescu Alexandru
Published: August 2024

Present study examines the impact of the quality of the GDL non-wetting coating on water transport. It is found that there are two distinct regions defined by the coating quality which present fundamentally distinct behaviours, one region characterized by few coating defects with the second marked by significant coating degradation. Simulations consider the influence of heterogeneous wetting and pinning conditions on protruding water droplets in contact with the GDL fibrous matrix. The impact is assessed by examining the breakthrough pressure as a function of protruding droplet volumes. When a non-wetting coating such as PTFE is applied, inherent coating defects determine a mixed-non-wetting (MNW) behaviour of water passing through the pores of the GDL. The MNW behaviour for a quasi-uniform non-wetting coating having less than 25% defects is characterized by a high breakthrough pressure, yielding improved transport properties in the stable displacement regime. The MNW meniscus is critical to establishing a high breakthrough pressure and a small characteristic droplet volume, parameters considered to be important in the design of a GDL that promotes optimal water transport. The coating degrades under normal operating conditions and as a consequence it changes the water transport characteristics of the porous medium. In this range where coating defects are predominant it is found that the water breakthrough pressure changes significantly, rendering poor performance below that of a non-coated wetting GDL. Various degrees of coating degradation are considered and the corresponding Laplace pressure is determined as a function of breakthrough droplet volumes.
Fundamental Studies of Discharge Mechanism and Capacity Limits of Lead Acid Battery Electrodes
Authors: Agyapong-Fordjour Frederick , Ferels Crystal , Buchanan Cailin , Becknell Nigel , Papa Lopes Pietro Papa
Published: August 2024

Long-duration energy storage provides key benefits such as consistent power supply during periods of high demand for grid reliability and flexibility. For environmental benefits, it allows for more renewable energy integration and helps reduce reliance on fossil fuels to lower greenhouse gas emission. Lead batteries have the economic potential to continue serving as an important energy storage technology for a decarbonized sustainable energy future given they are earth-abundant, inexpensive, and 99% recyclable. Advancing the design of lead batteries with higher material utilization, fast recharge rates, and long-cycle life requires a fundamental understanding of the electrochemical and chemical processes taking place at the atomic and molecular scales. In this work, we will discuss how the use of well-defined electrode interfaces allows us to gain insights into the fundamental limits of discharge capacity and recharge rates. We were able to unveil the relationships between discharge rates and PbSO4 particle size/layer thickness that ultimately governs the maximum discharge capacity accessible as a function of discharge rate on both the negative and positive lead electrodes. This data helped us develop a mathematical model that captures the key processes concerning lead ion and (bi)sulfate ion gradients coupled to nucleation and growth that explain, from first principles, the origin of the well-known empirical Peukert law. In this context, exploring how variables such as acid concentration, temperature, and the presence of lignosulfonate additives in the electrolyte further influence discharge capacity allows us to understand how thermodynamic, kinetic, and even mass transport play a huge role in governing the accessible capacity from the electrodes. This study paves the way for a deeper understanding of the variables that are most important in improving the discharge capacity of lead-acid batteries, and thus batteries that can be utilized at their full potential.
Redox Stability Analysis of Co-Doped Barium Niobate Thin Films Via Cyclic Voltammetry
Authors: Denoyer Luke H , Ramaiyan Kannan , Benavidez Angelica , Ferlauto Andre Santarosa , Fonseca Fabio Coral , Garzon Fernando H.
Published: August 2024

The electrochemical oxidative coupling of methane (E-OCM) to higher hydrocarbons, requires anodes that are stable under reducing conditions. We have previously demonstrated high activity with long term stability/durability for the perovskite anode BaMg0.33Nb0.67-xFexO3-δ (BMNF) while performing E-OCM1. Our group has also improved the total conductivity and activity of barium niobate perovskites via exchange of Mg for Ca (from 18 mS/cm-1 to 41 mS/cm-1), while also decreasing the Goldschmidt tolerance factor below 1 for increased cubic perovskite structural stability2. Perovskite metal oxide thin films can be produced with well-defined thicknesses and stoichiometries through pulsed laser deposition (PLD)3. These thin films are utilized in cyclic voltammetry experiments on YSZ substrates to further elucidate the chemical stability and oxygen sub-stoichiometry of high temperature SOFC/SOEC electrodes. Through application of reducing potentials to the electrode of interest, the voltage and current responses can be correlated to effective oxygen activities in which reduction of the electrode may occur. Usage of this technique with calcium and iron doped barium niobate perovskites (BaCa0.33Nb0.67-xFexO3-δ - BCNF) provides insights into the thermochemical stability and iron doping effects under highly reducing environments. The BCNF thin film electrodes were characterized via grazing incidence XRD and XRF for crystal structure and chemical composition. After initial characterization, cyclic voltammetry experiments were performed in a novel cell setup. These BCNF thin films show promise for evaluating stability mechanisms for E-OCM operation while providing details on compositional changes and oxygen loss of BCNF in reducing environments.

References:

(1) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene. Adv. Mater. Interfaces
2022, 9 (27), 2200796.

(2) Ramaiyan, K.; Denoyer, L. H.; Benavidez, A.; Garzon, F. H. Role of Dopants in Fine-Tuning the Electrical and Catalytic Properties of Barium Niobate Perovskites Towards High-Temperature Electrolyzer Application. ECS Trans.
2023, 111 (6), 1139.

(3) Anh, D. T. V.; Olthuis, W.; Bergveld, P. Sensing Properties of Perovskite Oxide La0.5Sr0.5CoO3−δ Obtained by Using Pulsed Laser Deposition. Sens. Actuators B Chem.
2004, 103 (1), 165–168.
(Invited) Insights from the Interplay of the Electrode Structure and the Microenvironment for Electrochemical CO2 Conversion
Authors: Wong Andrew Barnabas
Published: August 2024

The electrochemical CO2 reduction reaction (CO2RR) represents a critical approach toward the carbon-neutral generation of hydrocarbons. However, despite intense research efforts, the need remains to increase the selectivity and activity of electrocatalysts for CO2RR. Thus, there has been increasing interest in optimizing the microenvironment to boost the activity and selectivity of electrocatalytic sites for CO2 conversion.

This presentation discusses several strategies that are being pursued in my research group to optimize the microenvironment for CO2 conversion based on a detailed understanding of model systems for electrochemical CO2 conversion to C2+ products on Cu. Here, microenvironment-level insights from two model systems will be discussed:

The effect of localization of Ag co-catalysts in Cu nanowire arrays

The impact of the 3D interface on the microenvironment within model Cu nanowire array cathodes to boost C2 product activity

Overall, these insights can aid in the rational design of electrodes for electrochemical CO2 conversion.

Figure 1
(Invited) The Science of Scale-up: Accelerating CO2 Electrolyzer Development
Authors: Hahn Christopher
Published: August 2024

CO2 electrolysis has attracted significant industry interest given its potential to decarbonize production of top 5 commodities like ethylene, methanol, and propylene. However, defining a critical path for CO2 electrolyzer scale-up and deployment remains a challenge as it is a nascent disruptive technology. Here, I will briefly describe how we collaborated with industry to develop a risk assessment protocol that exposes researchers to a use-inspired mindset for early-stage research in lab environments. We identified and prioritized 87+ risks towards CO2 electrolyzer scale-up and deployment, defining a critical path that emphasizes improving electrolyzer durability and reliability. I’ll discuss experimental outcomes from shifting our project plan towards managing water and salt in CO2 electrolyzers. Finally, I will provide examples of how we have developed integrated physics-based modeling and analysis frameworks that inform electrolyzer operation.
(Invited) Electrosynthesis of Carbon Dioxide to Ethylene
Authors: Wong Andrew Allen , Goldman Maxwell , Baker Sarah , Varley Joel , Govindarajan Nitish , Marufu Michell , Krall Eric , Li Wenqin , Xia Xiaoxing
Published: August 2024

Electrochemical production of hydrocarbons provides a pathway for connecting renewable energy generation with chemical production. In this work, we present research on the targeted electrochemical reduction of carbon dioxide to ethylene, which has a global production volume of over 200 metric tonnes per year. The selectivity of carbon dioxide to ethylene is heavily dependent on cell architecture, surface interfaces, and operating conditions. We explore the tradeoffs of using a zero-gap cell design, and demonstrate the production of ethylene with greater than 30% selectivity at 200 mA/cm2 with an uncompensated full cell voltage of 2.7 V. We also present modifications to a copper catalyst cathode, and the effects of conditioning and variable operation on the electrochemical cell performance including selectivity and durability. Leveraging technoeconomic analyses, we will present the projected costs of this pathway for producing ethylene and conclude with a discussion on long-term operation failure modes which greatly impact the future feasibility of this technology.

Figure 1
(Invited) Impact of Cell Performance and Degradation on the Levelized Cost of Hydrogen
Authors: Casteel Micah
Published: August 2024

For electrochemical production of hydrogen to be industrially relevant it must be economically viable. As such, it is important that a reasonable understanding of the entire breadth of cost components which make up the levelized cost of hydrogen (LCOH) should be obtained. While a precise and detailed understanding may be impossible due to costing uncertainty and a constantly changing basis, a general idea is necessary to determine the most impactful research topics. This work seeks to elucidate the impacts of cell performance on the LCOH in comparison to other aspects such as feedstock costs, capital equipment cost, and fixed business costs. Based on initial analysis it appears a doubling of current density at thermal neutral conditions, a substantial materials achievement, may reduce the LCOH by less than 5%. This infers that while improving cell performance will reduce the LCOH, it may not provide the highest return on engineering and scientific investigation.
(Invited) Protonic Ceramic Electrochemical Cells for Hydrogen Production and Sustainable Chemicals Synthesis
Authors: Duan Chuancheng , Liu Fan , Fang Liyang , Wang Zixian
Published: August 2024

Protonic ceramic electrochemical cells (PCECs) are emerging as a promising technology for synthesizing chemicals with enhanced efficiency and sustainability. They exhibit versatility by efficiently synthesizing a wide range of chemicals using earth-abundant feedstocks such as H2O, N2, and CO2, while also contributing to the reduction of carbon footprint and improvement in energy efficiency during the upgrading of natural gas (methane). PCECs offer several notable advantages that set them apart from other chemical production technologies. One key advantage is their intermediate operating temperature range (300–600 °C), which thermodynamically and kinetically favors electrode chemistry. This temperature range also holds the potential for the simultaneous utilization of waste heat. In this presentation, we will highlight our recent achievements in utilizing PCECs for CO2 conversion and utilization, methane valorization, and hydrogen production.
(Invited) Enhancing Alkaline Water Electrolyzers: Insights into Activation Protocols, Loading and Ionomer Effects
Authors: Shviro Meital
Published: August 2024

Alkaline water electrolyzers (AWEs) are playing an increasingly important role in the renewable energy landscape due to their scalability and independence from scarce materials.1,2

This presentation will examine the various elements of AWE performance, emphasizing the critical role of activation protocols, loading dynamics, and ionomer characteristics.

Our investigation examined activation protocols and deciphering insights into the electrochemical initiation processes that are critical to optimizing AWE performance. At the same time, we investigate the nuanced relationship between loading and efficiency seeking the optimal catalyst loading for enhanced hydrogen production while maintaining operational stability. In addition, the influence of ionomers is investigated to understand their role.

By integrating these investigations, our work contributes to a holistic understanding of AWEs and provides practical insights to optimize their performance in renewable energy systems.

References

1 Aili, D.; Kraglund, M. R.; Rajappan, S. C.; Serhiichuk, D.; Xia, Y.; Deimede, V.; Kallitsis, J.; Bae, C.; Jannasch, P.; Henkensmeier, D.; Jensen, J. O. Electrode Separators for the Next-Generation Alkaline Water Electrolyzers. ACS Energy Lett. 2023, 8, 1900– 1910

Karacan C., Lohmann-Richters F. P., Shviro M., Keeley G. P., Müller M., Carmo M., and Stolten D., J. Electrochem. Soc., 2022, 169, 054502
Understanding Flooding in Cu-Gde Based CO2 Electrolyzers Via Real Time Mass Spectroscopy
Authors: Sajevic Urban , Parada Villarroel Walter Agustin Agustin , Nikolaienko Pavlo , Mayrhofer Karl J. J.
Published: August 2024

In the recent years, CO2 electrolyzers based on Cu-coated GDE systems became a hot topic of various research groups. As the field broadens, we are gaining better control over product selectivity, which coupled to achieving industrially relevant current densities (>300 mA/cm²), is bringing the inevitable widespread industrial adoption closer than ever. A huge limiting factor in economically viable big-scale CO2 electroreduction however, is still it´s long-term operational stability. The latter depends on two factors - catalyst stability and gas diffusion electrode´s resistance to electrowetting. In this work, we utilize a direct real time mass spectrometry approach to dive deeper into mechanism of GDE electrowetting, trying to understand what causes it and eventually make first steps in it´s prevention.
The Electrochemical Acetone/Isopropanol Hydrogenation Cycle: Full-Cell Performance of the Electrochemical Dehydrogenation of Isopropanol
Authors: Venus Dominik Maximilian , Marth Axel , Freiberg Anna T.S. , Brodt Matthew , Thiele Simon
Published: August 2024

Molecular hydrogen has exceptionally high gravimetric energy density but low volumetric energy density at ambient conditions. This discrepancy requires technical measures to increase its volumetric energy density for widespread hydrogen applications. Compressed hydrogen and liquified hydrogen are the most established hydrogen storage technologies. In addition, thermocatalytic liquid organic hydrogen carriers (LOHC) have drawn significant attention in the last decade.[1] LOHC couples consist of a hydrogen-lean and a hydrogen-rich form that can be reversibly converted into each other on demand. So far, only a few approaches adapted this hydrogen storage concept to electrochemistry. However, there is strong interest in electrochemical liquid organic hydrogen carriers (EC-LOHC) as electrochemical processes offer significant advantages like flexible operation, device size, scalability, and system simplicity.[2]

This contribution demonstrates the concept of acetone/isopropanol as an electrochemical liquid organic hydrogen carrier focusing on the electrochemical dehydrogenation of isopropanol in a polymer electrolyte membrane electrode assembly (PEM-MEA) setup. The isopropanol oxidation at a PtRu electrode shows two distinct oxidation peaks at 0.18 V vs. RHE and 0.75 V vs. RHE, whereby the first oxidation peak is associated with a selective oxidation of isopropanol to acetone, electrons and protons.[3] The produced protons travel from the PtRu anode through the PEM and recombine with the electrons at the Pt cathode to form hydrogen. Therewith, this configuration is an electrolysis cell that produces hydrogen out of isopropanol upon polarization above the reversible cell potential.

The study investigates the influence of acetone/isopropanol concentrations, temperature, and flow rates on the I-V characteristics of the electrochemical dehydrogenation of isopropanol at voltages below 0.35 V, revealing its possible potential as EC-LOHC.

References

[1] D. Teichmann, W. Arlt and P. Wasserscheid, International Journal of Hydrogen Energy
2012, 37, 18118–18132.

[2] A.J. Bard, M. Stratmann, Encyclopedia of Electrochemistry Volume 5 Electrochemical Engineering, Wiley, 2007, 4.

[3] P. Khanipour, F. D. Speck, I. Mangoufis-Giasin, K. J. J. Mayrhofer, S. Cherevko, and I. Katsounaros, ACS Applied Materials & Interfaces
2020 12 (30), 33670-33678.

Figure 1
Long Term Durability Investigation of Cu-Doped La2NiO4 Oxygen Electrodes in Solid Oxide Electrolysis Cells
Authors: Karki Surendra B , Springer Renaldo , Seymour Lorraine , Le Long , Liu Tian , Coyle Chris , Marina Olga A
Published: August 2024

State-of-the-art oxygen electrodes in SOECs, lanthanum strontium cobalt iron oxide (LSCF) and lanthanum strontium cobalt oxide (LSC), contain strontium. Undesired reactivity and migration of Sr cations during long-term operation was found to be detrimental to the electrochemical performance as they triggered formation of multiple oxide phases, including insulating phases and electrode or barrier layer delamination. Developing alternative electrodes that are devoid of Sr is very important for long-term operation of SOECs.

In this work, we synthesized and evaluated properties of La2NiO4-based compositions with a Ruddlesden-Popper structure. The Cu-doped La2NiO4 compositions made of nano-size particles exhibited an enhanced electrochemical performance when tested in SOECs during steam electrolysis for hydrogen production. Long-term durability of these electrodes was studied using planar Ni-YSZ electrode-supported cells with an active area of 1.5 (button cells) and 13 cm2 (2.5 cm x 5 cm cells). Compared to the Sr-containing electrodes, the La2Ni0.8Cu0.2O4 (LNCuO-20) demonstrated lower degradation rate at 1.3 Volt resulting in a current density over 1 A/cm2 at 750⁰C. Chrome and sulfur tolerance of these electrodes during long term operation will be discussed as well.