bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabricating Solid-State Batteries for Electric Aviation
Authors: Dornbusch Donald A , Usie Griffin , Huddleston William , Lin Yi , Viggiano Rocco P. 
Published: December 2024

All-solid-state lithium batteries are widely reputed as the next major step in energy storage technology on account their drastically improved safety over wet cells, as solid electrolytes lack the volatile compounds in wet electrolytes that make them combustible. This enhanced safety enables a far wider range of products and vehicles to go fully electric and aligns with future NASA missions that require high performing, reliable, and safe batteries. However, they currently face issues with implementation in both aeronautical and consumer products due to the often-poor mechanical properties of the solid electrolyte and relative difficulty to manufacture [1].
Typical solid-state electrolyte challenges were bypassed by incorporating a range of polymeric binders into a solid electrolyte suspension and cast onto a composite carbon-sulfide cathode to create a single bilayer film. The resulting films display superior flexibility and durability compared to solid-electrolyte films typically discussed in literature without compromising the thinness of the films. The bilayer film was then punched into 12.7 cm diameter discs and 4 cm by 5 cm sheets, pressed, and assembled into coin cells and pouch cells respectively.
[1] Donald A. Dornbusch, Rocco P. Viggiano, John W. Connell, Yi Lin, Vadim F. Lvovich. Practical considerations in designing solid state Li-S cells for electric aviation, Electrochimica Acta, 2021, 139406, ISSN 0013-4686, https://doi.org/10.1016/j.electacta.2021.139406.
Growth of Anodic Oxide Layers on Titanium Alloys Including Noble Metal and Transition Metal
Authors: Kim Jongwon , Tsuchiya Hiroaki , Fujimoto Shinji 
Published: December 2024

Anodic TiO2 nanotubes have attracted attention, especially in the field of photocatalysis, enabling the generation of hydrogen from water. It has been reported that the hydrogen production can be enhanced by decorating co-catalysts onto nanotubes, and that, nanoparticles consisting of noble metal alloys can be deposited onto TiO2 nanotubes by anodization of Ti alloys containing noble metals at reducing reliance on noble metals. In this study, we studied the anodization behavior and oxide layer formation on titanium alloys containing both noble and transition metals to reduce the amount of noble metals used.
Titanium alloys containing noble metals (Au, Pt) and transition metals (Cu, Fe, Co) were fabricated via the arc melting method. Anodization was conducted in ethylene glycol solutions containing fluorides and water using a two-electrode cell with a Pt plate serving as the counter electrode. Current generated during anodization oxidation was monitored, and the surface and cross-section of the oxide layers formed were observed with FE-SEM.
In the present work, ammonium fluoride and hydrofluoric acid were used as fluoride source. In the case of the electrolyte containing ammonium fluoride, SEM observations confirmed the formation of TiO2 nanotubes, along with the decoration of co-added metal nanoparticles on their surfaces and cross-sections. In contrast, in the electrolyte containing hydrofluoric acid, the formation of nanograss was confirmed. A significant number of co-added metal nanoparticles were observed on the surface and cross-sections of the formed nanograss. In this presentation, the effect of water content in the organic electrolytes on the formation of TiO2 nanotubes decorated with nanoparticles will be discussed.
Reduction and Oxidation Behavior of Rust Layers Under Aqueous Solution Films with Different Thicknesses
Authors: Kurooka Hayato , Tsuchiya Hiroaki , Hanaki Koushu , Yamashita Masato , Fujimoto Shinji 
Published: December 2024

It is well known that steel materials widely used in infrastructures corrode rapidly in atmospheric environments. As a result of corrosion, rust layers form on steel surfaces exposed to repeated wet and dry environments. In such wet and dry environments, redox reactions of rust layer may occur and accelerates the corrosion of steels. Such redox behavior can strongly depend on the composition of rust layer and the thickness of the solution film that is present on the surface in the wet stage. In this study, we investigated the effect of solution film thickness on the redox behavior of two types of rust layers with different compositions, i.e. FeOOH-rich and Fe3O4-rich rust layers.
Specimens used were carbon steels, on the surfaces of which either of rust layers was present, that is, FeOOH-rich or Fe3O4-rich rust layers. FeOOH-rich rust layers were produced though atmospheric exposure of carbon steel for 3 months. On the other hand, Fe3O4-rich rust layers were produced by dipping of FeOOH-rich rust layers in 0.1M Na2SO4 solution of pH 5 at 50 ℃ for 24 h. The specimens were subjected to the solution film test in which the rust layers were covered with 0.1M Na2SO4 solution film with various thicknesses. To avoid evaporation of the solution film, the specimens were put into tightly sealed container and kept in a thermostatic chamber at 50 ℃ for 24 h. After the test, the solution films on the specimen surfaces were removed and then dried at 60 ℃ and 50% R.H. for 6 h.
X-ray diffraction pattern obtained for the specimens indicated that main rust constituents in each specimen were Fe3O4, α-FeOOH, and γ-FeOOH. The mass fraction of each rust constituent was calculated from the peak intensity of the X-ray diffraction and based on the calculation, the Fe2+/Fe3+ ratios in the rust layers were estimated. The Fe2+/Fe3+ ratio in the FeOOH-rich rust layer increased after the solution film test and the increase varied depending on the solution film thickness. In the thinner range than 200 µm, the increase of the Fe2+/Fe3+ after the test was relatively low whereas in the thicker range than 200 µm, the increase was significantly large, indicating that the reduction of FeOOH predominantly occurred under thick solution film. The Fe2+/Fe3+ ratio in the Fe3O4-rich rust layer tended to decrease with decreasing the solution film thickness. These imply that the reduction and oxidation of rust layers depend not only on the thickness of the solution film present above rust layer but also its composition.
Effect of Ketjenblack Content on Ammonia Electrolytic Synthesis Ability of Ru/Ketjenblack/TiO2/Carbon Paper Catalysts at Low Temperature and Atmospheric Pressure
Authors: Yasuda Taketoshi , Shiroishi Hidenobu , Matsumoto Haruka , Nishitani-Gamo Mikka 
Published: December 2024

Introduction

Realizing a hydrogen society is a promising solution to the problem of global warming. Ammonia has attracted attention as a hydrogen carrier, and electrolytic synthesis of ammonia at low temperature and atmospheric pressure is a useful method for generating hydrogen carriers utilizing intermittent renewable energy. Employing a three-phase interface as the reaction field can potentially achieve practical electrosynthesis rates. We previously reported that a Ru/Ketjenblack-TiO2/Carbon paper catalyst exhibits ammonia electrosynthesis activity with a high Faraday efficiency of 26% under ambient conditions, compared to conventional catalysts. In this study, we investigated the effect of Ketjenblack (KB) loading amount in the catalyst on ammonia electrosynthesis performance using a half-cell with a three-phase interface.

Experimental

Catalyst Preparation: TiO2 (P25, Degussa) and Ketjenblack (KB, ECP-600JD, Lion) pastes with varying volume ratios were spray-coated onto hydrophobic-treated carbon paper (TGP-H-060, Toray). The carbon paper was heat-treated at 500°C for 1 h under 5 vol% O2 atmosphere to obtain KB/TiO2-modified carbon paper (KB/TiO2/CP) with a TiO2 loading of 0.5 mg cm−2. The KB loading was determined by the volume percentage (100×KB/(KB+TiO2)) and used as the catalyst name. Ru nanoparticles were electrodeposited onto KB/TiO2/CP (hereafter Ru/KB/TiO2/CP) in a RuCl3-0.1 M KCl solution using Pt wire counter electrode.
Electrochemical Measurements: The modified catalyst carbon paper was hot-pressed (135°C) with a Nafion® membrane (NR212, Dupont) to fabricate a membrane electrode assembly, which was incorporated into a half-cell with a three-phase interface, as shown in Fig. 1(a). Electrochemical measurements were performed using 0.1 M Na2HPO4-0.02 M KH2PO4 electrolyte, with N2 gas flowing. Ammonia electrolytic synthesis was carried out under N2 atmosphere using a square wave potential (5 s at electrolysis potential, 0.1 V for 1 s) for an actual electrolysis time of 1 h. The generated ammonia was collected in a 4 mM methanesulfonic acid solution and quantified using ion chromatography (column: Shodex IC YS-50, eluent: 4 mM methanesulfonic acid solution).

Results and discussion

Fig. 1(b) shows the ammonia electrosynthesis rates, Faraday efficiency, and energy conversion efficiency at −0.3 V vs. RHE with varying mixing ratios of KB and TiO2. The addition of KB increased the ammonia synthesis rate compared to KB-free catalysts, however it led to decrease in Faraday efficiency. Moreover, a further increase in the amount of KB addition resulted in a decrease in the ammonia production rate.

Figure 1
Synchrotron X-Ray Micro Computed Tomography Investigation of in-Situ Deformation of PFSA Membranes for Water Electrolyzers
Authors: Bergeson-Keller Anyka , Sabharwal Mayank , Kusoglu Ahmet 
Published: December 2024

Proton exchange membrane water electrolysis (PEMWE) is an electrochemical energy conversion technology that splits water molecules to produce hydrogen gas. PEMWE, when powered by renewable electricity sources, offers a promising solution to generate clean hydrogen fuel as well as for storing energy [1]. One barrier to the wide-scale commercialization of PEMWEs is their durability, which is compromised in part by mechanical damage to the membrane. It has been hypothesized that the rough surface of the PTL causes damage to the surface of the membrane in the form of pinholes and interfacial fractures under PEMWE operating conditions, which lead to increased degradation of the membrane and reduced performance and longevity of the PEMWE cell [3]. Furthermore, the extent of damage and deformation to the membrane can be related to the morphology (i.e. the feature and pore size/distribution) of the PTL. Thus, characterizing the interfacial contact between the PEM-PTL and the stresses induced in the membrane during operation is of great importance for understanding and mitigating the mechanical aspects of failure in PEM electrolyzers.
To investigate this phenomenon, we conducted X-ray micro computed tomography (MCT) at the advanced light source (ALS) at Lawrence Berkeley National Laboratory (LBNL) on a PTL/membrane stack being pressed together at 2.2, 4.4, 8.9, and 22.2 MPa using a custom compression stage. We tested the effect of two different standard PTL morphologies: a sintered Ti from Mott® and a fibrous Ti from Bekeart® on both wet and dry membrane specimens (Nafion 115). By carefully segmenting the X-ray MCT images, we were able to construct 3D strain mappings across the membrane to highlight areas of concentrated stress due to prominent features of the PTL protruding into the membrane and portions of membrane extruding into the pores of the PTL. Based on these results, we find that prominent features on the PTL surfaces lead to increased membrane surface roughness and strain, and indeed can pierce the hydrated membrane surface at elevated pressures. In summary, our study offers a unique insight into the deformation mechanisms that occur at the membrane surface as it interfaces with the PTL under standard PEMWE operating conditions of high compressive stress and hydrated states. This work will guide researchers within the PEMWE community to develop material and integration strategies that mitigate mechanical degradation and improve the system lifetime.
References
[1] Wang, Y.; Pang, Y.; Xu H.; Martinez, A. S.; Chen, K. S., Energy and Environmental
Science 2022, 15, 2288–2328.
[2] Hoppe, E.; Holtwerth, S.; Müller, M.; Lehnert, W., Journal of Power Sources 2023, 578
[3] L. Shi et al., Journal of The Electrochemical Society, vol. 167, no. 14, p. 144506, Nov.
2020. doi:10.1149/1945-7111/abc4bd
(General Student Poster Award Winner, 3rd Place) Biomimetic Auxiliary Channels for Enhanced PEM Fuel Cell Performance
Authors: Chadwick Eric Alexander , Shrestha Pranay , Parmar Harsharaj Birendrasingh , Bazylak Aimy , Schulz Volker Paul 
Published: December 2024

The bipolar plate of polymer electrolyte membrane (PEM) fuel cells is responsible for reactant delivery, liquid product water removal, and mechanical stability of PEM fuel cell stacks. Bipolar plates account for 70-90% of the weight and volume and 18-28% of the production costof stacks [1]. Improving the function of the flow fields embedded in the bipolar plates can significantly impact the energy density of PEM fuel cells by improving liquid water management and reactant distribution. Researchers have modified conventional flow fields by adding baffles or partially narrowed channels as semi-obstructive structures in the channels, exploiting Forchheimer’s intertial effect to locally increase gas velocity, thereby increasing oxygen diffusion and water removal in the GDL [2,3]. However, adding obstructions such as baffles or narrowed channels inherently increases the overall pressure drop across the flow fields, thus increasing the power required to supply reactant gases. In other attempts, biomimetic channel architectures have been shown to enhance preferential water flow; however, these designs have not been tailored to control water accumulation for improved reactant distribution [4,5]. Therefore, there is still a need to investigate flow field land-channel architectures that both enhanced inertial gas diffusion to the catalyst layer reaction sites and efficiently remove excess liquid water.
In this work, PEM fuel cell flow fields were laser-cut to enhance the liquid water removal and reactant distribution in the under-land region of the GDL. Operando synchrotron X-ray radiography revealed reduced GDL water accumulation when using our novel flow fields. The reduced mass transport overpotential and corresponding power density increase were attributed to enhanced liquid water removal and reactant distribution due to the flow field design. Ultimately, this work can be used to further optimize the design of bipolar plates for more efficient stacks and accelerate the commercialization of PEM fuel cells.
References:

Y. Wang, D. F. Ruiz Diaz, K. S. Chen, Z. Wang, and X. C. Adroher, Materials Today, 32, 178–203 (2020).

H. Guo, H. Chen, F. Ye, and C. F. Ma, Int J Energy Res, 43, 2737–2755 (2019).

H. Chen, H. Guo, F. Ye, and C. F. Ma, Int J Hydrogen Energy, 46, 2990–3007 (2021).

N. Guo, M. C. Leu, and U. O. Koylu, Int J Hydrogen Energy, 39, 21185–21195 (2014).

S. Feng et al., Science, 373, 1344–1348 (2021).
Facile, Fast, and Cost-Effective Fabrication of Iron-Based Electrocatalysts on Nickel Foam: Towards Highly Efficient, Stable, and Sustainable Water Splitting Performance
Authors: Lahrichi Amina , El Issmaeli Youness , Pollet Bruno Georges 
Published: December 2024

The development of effective, economical, and ecologically friendly catalysts for the oxygen evolution reaction (OER) is essential to advancing the production of hydrogen via electrolysis. Non-precious metal catalysts, known for their cost-effectiveness, abundance, lack of toxicity, stability, and efficiency, are at the cutting edge of this research field. Iron (Fe), the second most abundant metal on Earth, shows promise as a cost-effective alternative to traditionally used OER catalysts made from ruthenium (Ru), iridium (Ir), and cobalt (Co). Fe-based catalysts have typically shown limited OER activity, which has limited their practical use, despite their potential advantages.
This study presents a facile, fast, and unique approach to prepare iron-based transition metal phosphate films on nickel foam (TM-Fe-Pi/NF) for OER. The TM-Fe-Pi/NF electrocatalyst has been optimized to exhibit outstanding performance, with a remarkably low overpotential of +267 mV at a current density of 10 mA cm-2 in a 1.0 M KOH solution. Remarkably, this catalyst maintains its OER efficiency without significant degradation even after continuous operation for more than 10 hours, as confirmed by chronoamperometry measurements at a current density of 10 mA cm-2. In addition, the synthesis method used in this study produces catalysts that have exceptional uniformity, highlighting its potential for the efficient and cost-effective production of high-performance catalysts for industrial use.

Keywords: Iron phosphate; transition metals; KOH; water splitting; oxygen evolution reaction
Nature Derived Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells
Authors: Parmar Harsharaj Birendrasingh , Bazylak Aimy 
Published: December 2024

The adverse effects of global warming have accelerated the push for sustainable energy sources to meet the global energy demand. Renewable energy can be stored in the form of hydrogen to continuously produce clean power using a proton exchange membrane fuel cell (PEMFC). A typical PEMFC consists of a proton conductive membrane coated with platinum-based catalyst layers, which promote the hydrogen oxidation (anode) and oxygen reduction (cathode) reactions. Moreover, these catalyst layers are supported by gas diffusion layers, which supply reactants and facilitate the removal of water generated from the reduction reaction. While membrane hydration is necessary for maintaining protonic conductivity, excess water in the gas diffusion layer can severely inhibit the chemical reaction. Thus, efficient water management not only enhances reactant delivery but also substantially reduces the required platinum catalyst content in PEMFCs to ensure cost-effective power generation.
Interestingly, the simultaneous transport of water and oxygen is precisely optimized in trees, which are all around us. Thus, the hypothesis is that exceptional mass transport characteristics can be obtained using the organized microchannels of a novel nature-based basswood gas diffusion layer. First, basswood was carbonized to establish high electrical conductivities, and this was achieved while preserving their microstructure. Next, the microstructure of the carbonized basswood blocks was characterized using scanning electron microscopy. Finally,electrochemical testing of the carbonized basswood gas diffusion layer was performed to compare its performance with a conventional carbon paper gas diffusion layer. The mass transport behavior was characterized using electrochemical impedance spectroscopy. Through the application of our novel basswood gas diffusion layer, we provide new insights into the potential for high performance wood-based materials for clean energy, guiding the design of next generation sustainable fuel cell materials.
Tailoring Electrolyzer Catalyst Layer Morphology Via Pore Network Modelling
Authors: Seip Tess , Lee Jason Keonhag , Shaigan Nima , Dinu Marius , Fatih Khalid , Bazylak Aimy 
Published: December 2024

Polymer electrolyte membrane (PEM) water electrolysis is a key technology to produce clean, high purity hydrogen, which can serve as an alternative to carbon-based fuels. However, PEM electrolyzer uptake has been sluggish due to high catalyst costs, which can contribute to up to 47% of total stack costs [1]. Thus, to lower stack costs, the morphology of the catalyst layer must be optimized towards lower precious metal loadings. However, catalyst layer morphology optimization remains a challenge, as the mechanisms linking catalyst morphology to mass and charge transport remain ambiguous in the literature [2], [3]. While the morphology of porous transport layer (PTL) has been extensively explored via stochastic material generation and pore network modelling techniques [4], such an analysis must also be extended to the catalyst layer to design efficient, low-cost materials.
In this work, we introduce a method to replicate the pore structure of commercially available PEM electrolyzer catalyst layers using stochastic generation techniques. Our method employs a custom divider to combine regions of varying pore sizes and effectively replicate the range of catalyst layer pore sizes observed in commercial materials. Moreover, we demonstrate that the pore size distribution of stochastically generated materials is statistically indistinguishable from imaged catalyst samples. Pore network modelling techniques were further applied to stochastically generated morphologies to evaluate electrical and mass transport properties. We not only reveal that the transport properties of our stochastically generated materials fall within experimentally measured ranges, but also reveal how tailoring pore size distributions can enhance these properties. The findings from our analysis can be used to identify desirable catalyst morphology targets for manufacturing and enhance the accuracy of electrolyzer transport models via the estimation of catalyst layer transport properties.
[1] A. Mayyas, M. Ruth, et al., Manufacturing Cost Analysis for Proton Exchange Membrane Water Electrolyzers, United States (2019).
[2] Z. Taie, X. Peng, et al., ACS Appl. Mater. Interfaces, 12, 47, 52701–52712 (2020).
[3] J. Lopata, Z. Kang, et al., J. Electrochem. Soc., 167. 064507 (2020).
[4] J. K. Lee, C. H. Lee, and A. Bazylak, J. Power Sources, 437, 226910 (2019).