bluuebunny/crossref_metadata_2025 huggingface dataset:
High Entropy Oxides Synthesis by Rapid Plasma Generation with Applications Towards Electrocatalytic Hydrogen Generation
Authors: Abdelhafiz Ali , Li Ju
Published: September 2023

It has been challenging over the past three decades to find viable energy alternatives with higher efficiency and lower cost to beat the non-friendly and commercially dominant hydrocarbon energy sources. Hydrogen is deemed to be one of the most prominent candidates, as a green fuel. Hydrogen can be generated in abundance from water splitting. Utilization of hydrogen in fuel cells, with no doubt, produces no harmful gases. Nevertheless, the two parts of the technology: hydrogen production and reduction are cumbersome. Both processes rely on kinetically sluggish electrocatalytic reactions. Enormous research efforts have been spent, with thousands of studies presented in literature, despite the technology left with a dim light shed on from commercial and practical point of views. Many materials-related challenges are hindering the flourishing of green hydrogen technology, where poor catalyst durability is a major challenge, despite being made from very expensive elements (e.g., Ir, ru or Pt). Therefore, gigantic effort of research has been devoted to find inexpensive alternatives. Transition metals showed interesting performance towards water splitting (e.g., oxygen evolution (OER)).

Recent research showed that electrocatalysts designed by alloying two or more elements (e.g., transition metals) showed promising enhancement in catalytic activity and durability due to synergistic effects from alloying, such as strain engineering or electron exchange. The potential of the alloying approach is constrained by standard synthesis methods (e.g., wet chemistry and thermal decomposition techniques) due to the governing thermodynamics rules (e.g., miscibility of the different alloying elements). That renders the synthesis of high entropy alloys (HEA), with more than 3 elements, to be complicated and tedious to achieve by those conventional methods.

In the presented talk we are presenting the utilization of microwaves to generate plasma to synthesize metastable high entropy oxides (HEA) and their outstanding catalytic performance towards OER, in correlation to their unique chemistries and structures. Plasma generated enable temperature increase of the precursor substrate to elevated levels (~1000s °C), in conjunction with rapid cooling, within seconds range. Our results show successful synthesis of non-noble metals HEA NPs, possessing higher catalytic activity than IrO2 catalyst for OER. The nature of the alloying elements dictates OER activity by promoting different oxidation states of the catalytically active transition metals (e.g., Fe, Ni and Co). Our developed techniques resulted in formation of super-strong metal-carbide bonds “chemically welding” HEA NP to the catalyst support.
Exsolution Synthesis of Alloyed Nanoparticles from Perovskite Oxide by Plasma
Authors: Li Qinghao , Zhou Jun , Zhu Zi-He , Fu Lei , Yang Jiaming , Wu Kai
Published: September 2023

Bimetallic alloy nanoparticles (NPs) exsolved on the surface of perovskite oxides (ABO3) alter the structural and electronic properties of the primarily monometallic counterparts. These synergistic effects make the whole material present superior electrolytic and catalytic performances. The strong bonding interaction between alloy NPs and perovskite substrate enables the stability and durability of the catalysis.

However, traditional thermal exsolution requires a long-time treatment at a high temperature. Researchers have been pursuing more time-saving and energy-efficient alternative routes. Herein, a low-temperature and fast pathway based on the dielectric barrier discharge (DBD) reactor is provided to in-situ exsolve alloy NPs. A favorable activity of the catalyst for CO oxidation is demonstrated. Additionally, we conclude that the factor restricts metallic agglomeration is the morphology of the substrate. Even after an overtime plasma treatment, the exsolved alloy NPs are still embedded in the porous structure of perovskite oxides.
(Invited) Efficient Carbon Sulfonation Using Plasma in Contact with Dilute Sulfuric Acid
Authors: Takeuchi Nozomi , Deng Siqi , Takahashi Katsuyuki , Tachibana Kosuke , Hieda Junko , Li Oi Lun
Published: September 2023

Heterogeneous catalysis is a promising technology in biomass valorization because of its high reactivity, easy post-separation, and great recyclability compared to homogeneous catalysis. Various functionalized catalytic materials have emerged as promising alternatives to the homogeneous liquid acid catalyst, such as carbon materials, metal–organic frameworks, and metal nanoparticles. Among them, carbon materials such as carbon nanotube, graphene oxide, carbon black, and so on have been investigated as catalysts for cellulose hydrolysis to produce glucose.

Carbon materials show considerable catalytic activity by functionalization with active acidic groups including hydroxyl groups (-OH), carboxyl groups (-COOH), and sulfonic groups (-SO3H). Hydroxyl and carboxyl groups on the carbon catalysts act as connection center to access cellulose, where sulfonic group serves as the active site to cut off the linkage between glucose units in cellulose. So, the surface modification of carbon materials with these functional groups, namely, carbon sulfonation process, becomes the determining step to producing efficient carbon acid catalysts. Conventional methods for the carbon sulfonation are the hydrothermal and reflux method, in which hazardous chemicals are necessary, such as concentrated sulfuric acid (95–98%), chlorosulfonic acid, fuming sulfuric acid, or 4-benzenediazoniumsulfonate under elevated temperature for dozens of hours. As a green and effective carbon sulfonation process, we have utilized gas–liquid interfacial plasma (GLIP).

In the GLIP process, plasma is generated between the tips of multi-needles and the surface of dilute sulfuric acid which contains carbon particles in N2/Ar gas mixture. The optimized catalyst synthesized from graphene nanoplatelets by the GLIP process achieved a conversion rate of 41.5% with high glucose selectivity of 84.3%, which is superior to performance of catalysts synthesized by the hydrothermal method. The concentration of sulfuric acid, reaction temperature, and reaction time for the GLIP process were 1 M, 40℃, and 0.75 h, respectively while those of the hydrothermal method were 18 M, 200℃, and 24 h, respectively. Thus, the GLIP process is less hazardous and more efficient. Significantly, the catalyst synthesized by the GLIP process also exhibited superior recyclability of 95.9% in 3 times cycle tests for cellulose hydrolysis.

Recently, we have investigated the mechanism of carbon sulfonation in GLIP processes. Active species produced near the gas–liquid interface such as ·OH, SO3, and HOSO2· probably play important roles in carbon sulfonation. We are trying to observe gas-phase active species by Fourier transform infrared spectroscopy and quadrupole mass spectrometer, and liquid-phase active species by electron spin resonance spectroscopy.
(Digital Presentation) Electrochemical Reduction of Pressed Tungsten (VI) Oxide on a Solid Electrode in a Melt of Calcium and Sodium Chlorides
Authors: Medvezhynska Olha , Omel'chuk Anatoliy
Published: September 2023

This report presents the results of research on the electrochemical reduction of tungsten (VI) oxide in a molten electrolytic mixture of CaCl2-NaCl of eutectic composition. The electrochemical behavior of tableted WO3 on a solid tungsten electrode was studied by voltammetry. Analysis of the obtained products was carried out by X-Ray diffraction and electron microscopy.

During the electrochemical reduction, pressed cylindrical samples were placed on a tungsten disk, which served as a cathode. A silica cloth impregnated with a CaCl2-NaCl eutectic melt was placed on top of the tableted sample in order to prevent a short circuit in the cell. The silica cloth and tableted tungsten oxide were pressed to the cathode by the anode. The anode was made of low-porous graphite, and the current was supplied to it with a molybdenum wire. The electrode assembly prepared in this way was placed in a crucible with molten chlorides of calcium and sodium.

Analysis of the obtained results indicates that reduction processes occur in pressed tungsten oxide (Fig. 1, a). According to the results of X-Ray phase analysis, in the surface layer of pressed tungsten (VI) oxide, which was in contact with the cathode, when the amount of electricity (Q) twice greater than that required for the complete recovery of loaded tungsten trioxide was passed, the following phases were detected: W, CaWO4 and a small amount of NaxWO3. Having studied the entire volume of the tableted sample, the following phases were recorded: NaxWO3 (main phase) and CaWO4, W (Fig. 1, b). The formation of phases of sodium and calcium tungstates is explained by the interaction of tungsten trioxide with the components of the melt. Passing electricity through the pressed sample causes electrochemical reactions to occur with the formation of tungsten metal, which grows from the cathode/WO3/electrolyte interface into the sample volume.

During galvanostatic electrolysis (i=0.4 A/cm2) of a pressed sample of tungsten (VI) oxide with a mass of 0.43 g (r=0.4 cm, h=0.174 cm) and a duration of 6 hours (Qpractical/Qtheoretical = 6), the degree of extraction of tungsten from tungsten trioxide is not less than 97.48%, and the current yield is about 29.06%. The X-Ray diffraction pattern of the obtained product under such conditions confirms the presence of only a monophase of crystalline tungsten (Fig. 1, b).

Figure 1
Rhenium Electrodeposition to Enable Functionally Graded Films
Authors: McBride Michael , Clark Courtney L , Hooks Daniel E , Dervishi Enkeleda
Published: September 2023

Rhenium (Re) has one of the highest melting points of all the metals with a high modulus of elasticity and superior tensile strength when compared to other refractory metals. However, processing challenges from the high temperature stability combined with the relative occurrence require advanced manufacturing approaches to leverage the unique properties of rhenium. The electrodeposition of rhenium has received renewed attention in the past decade as a scalable approach to apply uniform coatings to enable a wide range of applications in aerospace, nuclear, catalysis, biomedical fields. However, Re has traditionally been difficult to deposit by electrolysis from aqueous solutions due to the over potential for hydrogen evolution and complex electrochemical reactions.

Beginning with the perrhenate anion (ReO4
-), reduction from the +7 oxidation state must occur to deposit metallic Re. The exact mechanism of this process is still unknown with reductions to ReO2, ReO3, and Re2O5 along with metallic Re. Combined with the hydrogen evolution reaction, Re coatings are generally deposited at low faradaic efficiency, are brittle, and limited in the obtainable thickness (sub-micron).

Herein, we present systematic studies progressing towards the development of stable and efficient electrolytes to enable the electrodeposition of thick (100+ microns) Re coatings. Borrowing the water-in-salt electrolyte method from the lithium battery literature enables near room-temperature electrodeposition of Re. Specifically, we correlate nucleation and growth mechanisms of Re with the ability produce thick coatings. Pulse/pulse reverse electroplating was applied to manipulate the obtained grain structure and distribution of rhenium moieties. Correlations between the electrolyte composition and the pulse parameters with the observed morphology will be discussed with an emphasis on enabling industrially relevant electroplating processes.

The goal of this project is the electrodeposition of rhenium-cobalt (Re-Co) graded compositional/density samples of millimeter thickness. Thus, understanding how to transition from a coating or pure metallic rhenium to a graded composition of Re-Co as a function of dynamic processing conditions will be presented.
EIS Measurements to Quantify the Content of Organic Additives in Complex Matrices of Copper Plating Baths
Authors: Verrucchi Margherita , Comparini Andrea , Bonechi Marco , Mariani Elena , Meoli Arianna , Donati Lorenzo , Innocenti Massimo , Giurlani Walter
Published: September 2023

Commercial plating baths may contain a large number of organic additives that play an important role in ensuring good-quality deposits. During electrodeposition process these compounds tend to wear out and degrade, so they must be frequently monitored and dosed to keep constant their concentration. Plating baths are complex matrices in which organic additives are present in minimal quantities compared to the other components, electrochemical methods, therefore, represent a reliable alternative to conventional chromatographic techniques because they allow quantitative analyses to be carried out considering the effects of additives on the electrodeposition rate regardless of their chemical composition and provide, at the same time, useful information about the condition of the bath. Methods based on the Cyclic Voltammetric Stripping (CVS) technique can be employed to quantify additives generally used in commercial acid copper plating baths. However, such procedures tend to be time and reagents-consuming and do not always provide accurate results. Electrochemical Impedance Spectroscopy (EIS) can represent a reliable alternative because it allows to achieve a detailed knowledge of the function of each additive and the interactions between them and to study the aging of plating baths [1]. EIS measurements were performed to quantify the three main additives present in commercial acid copper plating baths. These baths are widespread in different industrial sectors, such as fashion and electronic. The experiments were performed in three-electrodes cell, at 30 °C, by using a 105 – 10-2 Hz frequency range. A large number of samples were investigated for a statistical treatment of the results that allowed us to find correlations between the concentration of each additive and some of the components of the equivalent circuit used to fit the data. The procedure applied to real samples provided promising results.

The authors acknowledge MUR and EU-FSE for financial support of the PhD fellowship PON Research and Innovation 2014-2020 (D.M 1061/2021) XXXVII Cycle in Chemical Sciences.

References

[1] Gabrielli, C. et al. Journal of Applied Electrochemistry 2008, 38, 457-468, doi: 10.1007/s10800-007-9459-1
Integrating Sustainable Design into Advanced Electrochemical Manufacturing
Authors: Bruce David Robert
Published: September 2023

Considering the green engineering principles developed by Anastas and Zimmerman or detailed from the Sandestin conference of 2004 as presented by Abraham and Nguyen there is a duty of care as environmental stewards of our technology to closely examine where we can reduce impact regarding nascent electrochemical technologies.

Comparison of state-of-the-art electrochemical manufacturing technologies highlight the design options competing technologies offer when we consider the sourcing, manufacturing, emissions, and other ways of embodying the environmental footprint of our designed processes.

Impact on natural systems, circular life-cycle thinking and creating engineering solutions beyond our current or dominant manufacturing technologies to improve, innovate and invent solutions for a transition to a clean energy future are highlighted. Principles of conservation and improvement of natural ecosystems are considered to inform novice scientists and engineers and lead to insight in opportunities for advanced system developments for mature industry representatives and experienced experts.

Challenges in greening of existing systems offers opportunities for continued growth in the industrial domain. Triple bottom line examination of how our actions can improve manufacturing processes, as well as benefit globally relevant sustainable development goals. Reframing the basis for how we design electrochemical processes from a cost-efficiency relationship to include additional considerations in our practice using simple guidelines to address cell architectures, integration and interconnection of energy and material flows, and careful material selection are shown to have a win-win benefit when we examine intergenerational scope of our practice.
(Invited) Predicting Voxel Scale Geometry and Properties in Vat Photopolymerization Via Microscopic and Machine Learning Methods
Authors: Killgore Jason P.
Published: September 2023

Additive manufacturing (AM) promises disruption of traditional manufacturing supply chains, democratizing and distributing manufacturing, enhancing flexibility and enabling previously impossible geometries and customization. Applications range from aerospace to regenerative medicine, leveraging the numerous benefits of the technology. Within polymer AM, vat photopolymerization, enabled by advances in high-resolution display technologies (e.g. liquid crystal display - LCD, digital light processing - DLP) to locally cure liquid resin into solid polymer, prints millions of voxels per layer simultaneously in a few seconds or less. Typically, these layers are combined step-wise until a 3-dimensional part is formed. Fundamental understanding and control of the printing process with geometrically and mechanically precise voxels requires characterization of parts at voxel and sub-voxel length scales. Despite the precise, high-resolution light engines, resultant parts exhibit defects such as over/under-polymerization, 3-dimensional anisotropy, weakened layer interfaces and more. In this presentation, we examine the formation of these defects starting from individual voxels and simple patterns, but extending to complex voxel-voxel interactions. We discuss novel, multiscale measurement tools such as atomic force microscopy and laser scanning confocal microscopy that elucidate the small-scale printing process in both space and time. The novel characterizations are used to develop new models of the printing process and enable precise geometric and mechanical control of the individual voxels. Finally, we introduce the use of neural network models and big-data to predict the output of arbitrary photomasks.
Simulation as a Tool for Electropolishing Industrialization
Authors: Boucher Aurelien , Doche Marie-Laure , Hihn Jean-Yves , Fedi Baptiste , Exbrayat Loic
Published: September 2023

Although the production of parts by additive manufacturing allows a great degree of freedom in design, a recurring problem lies in surface finish compared to the one produced by conventional machining, with important roughness and the risk of detachable particles presence. To overcome these issues, finishing processes are required, such as electropolishing for example. This electrochemical process relies on specific know-how, particularly in the choice of process parameters (agitation, electrical conditions, etc.). However, the high-complexity level of the geometries encountered requires a dedicated cathodes, which necessitates several iterations before reaching suitable configurations. Numerical simulation of electropolishing processes, for different conditions or different materials, allows predicting the thickness and roughness reduction. Indeed, it is possible to run simulations for complex geometries while taking into account agitation. Therefore, numerical studies of different cathode configurations allow a drastic reduction of the number of experimental tests, and therefore an acceleration of the industrialization.

Figure 1
Exploring Surfactant Electrolyte-Porous Electrode Interactions
Authors: Barth Brian , Zawodzinski Thomas A.
Published: September 2023

Microemulsions are an alternative to aqueous organic electrolytes for redox flow batteries (RFB) that can be modified without synthesis. Water, oil, and emulsifiers, when combined using optimized chemistries and compositions, produce stable mixtures with aggregate structures (microemulsions). Design limitations imposed by the interdependency of redox solubility and electrolyte conductivity are circumvented by solubilizing redox active molecules in the oil phase and supporting ions in the aqueous phase. While macroscopically homogeneous, microemulsions are biphasic at the nanometer scale, effectively decoupling solubility from conductivity. Recently, the first microemulsion RFB was demonstrated using ferrocene solubilized in an anionic surfactant system. Polarization curve analysis revealed performance limitations seemingly arising from electrolyte interactions with the cell components including porous electrodes. Further optimization requires a deeper understanding of microemulsion-porous electrode interactions.

Due to the complexity of microemulsion electrochemistry, a first step towards understanding these interactions is made by investigating the relationship between surfactants and porous electrodes. Vanadium redox flow battery (VRFB) electrolytes with surfactant additives are used as a model system to explore fundamental interactions, in situ, between a surfactant-containing electrolyte and a porous electrode. Transport and kinetics are evaluated as a function of electrode, electrolyte, and surfactant properties. Redox species transport is quantified through mass transfer coefficients, using a generalization of an existing porous electrode model fit to experimental polarization curve data. Electrochemical impedance spectroscopy, interpreted using existing kinetic models, is also employed to gain insight into the effects of surfactant on electron transfer rates.
Bipolar Anodization for the Synthesis of TiO2 Nanotube Layers: New Concepts and Cell Designs
Authors: Sopha Hanna , Sepúlveda Sepúlveda Lina Marcela , Macak Jan M.
Published: September 2023

Self-organized TiO2 nanotube (TNT) layers have attracted considerable scientific and technological interest over the past almost 20 years, due to their wide range of applications, including (photo-) catalysis, hydrogen generation and biomedical uses [1,2]. The synthesis of these TNT layers is usually carried out by electrochemical anodization of valve Ti metal substrates in various F--containing electrolytes using a conventional 2-electrode set-up with the Ti substrate as anode and a Pt-foil as cathode.

By now, the TiO2 nanotube layer modification of Ti substrates is mainly focused on planar substrates, such as Ti foils and 2D Ti meshes, as these substrates can easily be connected to the potentiostat during anodization. However, for the real application in photocatalytic cleaners, 3D Ti substrates, such as 3D meshes or Ti spheres, are of high interest due to their significantly increased surface area compressed in a small volume.

To anodize such 3D Ti substrates towards TiO2 nanotube layers, bipolar electrochemistry can be employed instead of using a conventional set-up [3-5]. In such a bipolar set-up, the Ti substrate is not directly connected to the potentiostat but placed in an electrolyte between two so-called feeder electrodes. Due to the electric field between the feeder electrodes, the Ti substrate is polarized and can be anodized if the applied potential between the feeder electrodes is high enough. This method opens the door for the preparation of TNT layers with gradients in dimensions (i.e. diameter and length of the nanotubes) [3-5] as well as for the preparation of TNT layers on Ti substrates, which cannot be directly connected to the potentiostat, e.g. small Ti spheres [6] and complicated 3D printed structures [7].

In this presentation, the preparation of TNT layers on small Ti spheres [6] as well as on 3D printed Ti substrates [7] using bipolar electrochemistry will be shown. Their application in liquid and gas phase photocatalysis will be discussed. Furthermore, we will also show the possibility of using closed bipolar electrochemical cells, consisting of two closed half-cells with the Ti substrate as obstacle between the cells for the preparation of TiO2 nanotube layers with different dimensions on the two sides of a classical Ti foil [8].

References:

[1] J.M. Macak et al., Curr. Opin. Solid State Mater.
2007, 11, 3.

[2] Lee, K. et al., Chem. Rev.
2014, 114, 9385.

[3] G. Loget et al, J. Mater. Chem A
2014, 2, 17740.

[4] G. Loget et al., Langmuir
2014, 30, 15356.

[5] W. Wei et al., Electrochim. Acta
2015, 176, 1393.

[6] H. Sopha et al., Electrochem. Commun.
2020, 111, 106669.

[7] H. Sopha et al., Nano Lett.
2021, 21, 8701.

[8] H. Sopha et al., ChemElectroChem
2021, 8, 3827.
Wide and Thin Li Metal Powder Electrodes and Their Electrochemical Performances
Authors: Lee Yong Min
Published: September 2023

Li metal powders are very useful in fabricating wide and thin Li metal electrodes due to its ease applicability to slurry-coating process. Furthermore, not only microstructure but also functional components can be controlled or added in Li metal power electrode. These beneficial characteristics can lead to more stable and robust Li metal electrode comparing to the conventional extrusion/roll-pressed, electroplated, or vacuum evaporated Li metal electrodes. In this work, we introduce how thin and wide the Li metal electrode can be fabricated using the conventional slurry-coating method. And then, it is also included how binder-induced scaffold-like electrode structure can improve the electrochemical performances of Li metal electrode. Furthermore, the role of some inorganic additives like CNTs, LiNO3 or AgNO3 will be also discussed with significant electrochemical performance enhancements. Finally, these Li metal powders are being investigated to lithiate diffusion-dependent electrodes especially for all-solid-state batteries.

[References]

1. D. Kang†, D. Jin†, H. Lee*, S.-Y. Ryou*, Y. M. Lee* et al., Chemical Engineering Journal, 452 (2023) 139409

2. C. B. Dzakpasu, H. Lee*, S.-Y. Ryou*, Y. M. Lee* et al., Electrochimica Acta, 430 (2022) 141093

3. J. Kim†, S. Jung†, Y. M. Lee* et al., Advanced Energy Materials, 12 (2022) 2103108

4. D. Jin, M.-H. Ryou*, H. Lee*, Y. M. Lee* et al., Advanced Energy Materials, 11(18) (2021) 2003769

5. D. Jin, M.-H. Ryou*, Y. M. Lee* et al., Chemical Engineering Journal, 406 (2021) 126834

6. D. Jin, Y. M. Lee*, M.-H. Ryou* et al., Electrochimica Acta, 364 (2020) 136878
Development of Graphite Anodes from Coal Derived Carbon from Pitch
Authors: Paul Abigail , Magee Regan , Wichert Nathan , Wilczewski Warren , Mollah Rafid , Jones Matthew , Trembly Jason , Staser John A. , Garrick Taylor R.
Published: September 2023

Lithium ion battery demand is expected to increase 10x over the next decade. Much of the materials for lithium ion batteries are sourced from overseas. The United States possesses vast coal reserves that have historically been used to generate electricity. That application is on the decline as cleaner sources of electricity are brought online, which leads to economic impact in coal-producing regions. Coal could also serve as a carbon source for battery-grade graphite if sufficient production procedures are developed. This group has been developing coal-derived graphite for these applications.

This presentation will discuss our efforts to develop coal-derived graphite and integrate it into lithium ion batteries. Typical formation cycles, charge/discharge cycling, and HPPC profiles will be presented. The performance of lithium ion batteries containing coal-derived graphite will be compared to those containing only typical battery-grade graphite. Future directions will be discussed, including possible performance impacts and preliminary techno-economic assessments.
Tailored Pre-Lithiation of Carbon Anodes Using Melt Deposited Thin Lithium
Authors: Schönherr Kay , Pöthe Markus , Schumm Benjamin , Althues Holger , Leyens Christoph , Kaskel Stefan
Published: September 2023

The user demands for Lithium ion batteries in mobile applications and electric vehicles request steady improvement in terms of capacity and cycle life. State-of-the-art lithium ion batteries irreversibly loose about 10 % of the capacity during the first cycles due to SEI formation. Therefore, 10 % of the cathode material is not used during the rest of the cells life which results in a waste of cathode material and leads to a lowered range of battery electric vehicles. Therefore, these losses must be compensated to ensure efficient resource utilization and to further increase the capacity of the lithium ion battery.

We have developed a method to compensate these capacity losses by pre-lithiation: A fast and simple approach of electrolyte-free direct contact pre-lithiation leads to targeted degrees of pre-lithiation in a range of 7-50 % for state-of-the-art graphite electrodes. The parameters pressure (0-40 MPa), temperature (20-150°C) and time (0-60 min) are used to transfer lithium from a temporary substrate to the graphite anode. This process uses 1-5 µm thin lithium films made by the Fraunhofer IWS lithium melt deposition process as a lithium source.[1] The degree of pre-lithiation can be controlled by the lithium loading of the temporary substrate. NCM full cells built with pre-lithiated graphite electrodes where electrochemically evaluated in comparison to unlithiated electrodes. They show 6.5 % capacity increase after the first cycles using the additional lithium to form the SEI during the first cycles. The parameter influence of the pre-lithiation process on the initial coulomb efficiency of cells with pre-lithiated graphite electrodes is examined in half cells showing an ICE of 99.91 % for the best parameters.

This method of electrolyte-free direct contact pre-lithiation shows an efficient way to further increase the capacity of state-of-the-art LIBs with graphite electrodes by increasing the cathode material utilization. It can potentially be scaled up to a roll-to-roll process using a heated calender nip. The temporary substrates with tailored lithium loading can be processed by lithium melt deposition in an efficient way with high lithium yield and high precision.

[1] K. Schönherr, B. Schumm, F. Hippauf, R. Lissy, H. Althues, C. Leyens, S. Kaskel, Chemical Engineering Journal Advances
2022, 9, 100218.

Figure 1
Understanding the Degradation Mechanisms in Lithium Manganese Oxyfluoride Cathodes
Authors: Pi Liquan , Björklund Erik , Rees Gregory , House Robert , Bruce Peter
Published: September 2023

The development of next-generation nickel and cobalt-free Li-ion batteries with significantly greater energy density for electric vehicles is largely contingent on the discovery of new cathode materials. A number of novel candidates with a disordered rocksalt crystal structure have recently been reported to exhibit high capacities, offering a highly promising new avenue for cathode research.1–5 However, disordered rocksalt cathode materials generally suffer from voltage and capacity fade over cycling. For example, the Mn-based archetypal oxyfluoride Li2MnO2F shows 254 mAh g-1 discharge capacity in the first cycle but fades to 104 mAh g-1 after 100 cycles. For improving these materials leading to practical devices, it is vital to develop an understanding of the fading mechanisms.

Various explanations have been proposed for the gradual deterioration in performance of disordered rocksalt oxide and oxyfluoride cathodes. These include O-loss and surface densification4,6, growth of a CEI layer7, phase segregation6,8. In this study, we examine the main degradation mechanisms in Li2MnO2F over cycling and demonstrate that the capacity and voltage retention can be improved through compositional control, figure below. This understanding points the way to manganese oxyfluorides with better cycling performance.

House, R. A. et al. Lithium manganese oxyfluoride as a new cathode material exhibiting oxygen redox. Energy Environ. Sci.
11, 926–932 (2018).

Lee, J. et al. Reversible Mn2+/Mn4+ double redox in lithium-excess cathode materials. Nature
556, 185–190 (2018).

Yabuuchi, N. et al. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries. Nat. Commun.
7, 1–10 (2016).

Li, L. et al. Fluorination‐Enhanced Surface Stability of Cation‐Disordered Rocksalt Cathodes for Li‐Ion Batteries. Adv. Funct. Mater.
2101888, 2101888 (2021).

Chen, R. et al. Disordered lithium-rich oxyfluoride as a stable host for enhanced Li+ intercalation storage. Adv. Energy Mater.
5, (2015).

Chen, D., Kan, W. H. & Chen, G. Understanding Performance Degradation in Cation-Disordered Rock-Salt Oxide Cathodes. Adv. Energy Mater.
9, 1–15 (2019).

Källquist, I. et al. Degradation Mechanisms in Li2VO2F Li-Rich Disordered Rock-Salt Cathodes. Chem. Mater.
31, 6084–6096 (2019).

Chen, D., Ahn, J., Self, E., Nanda, J. & Chen, G. Understanding cation-disordered rocksalt oxyfluoride cathodes. J. Mater. Chem. A
2, 7826–7837 (2021).

Figure 1
Reversible Iron Oxyfluoride (FeOF)-Graphene Composites as Sustainable Cathodes for High Energy Density Lithium Batteries
Authors: Liu Yadong , Yu Yikang , Xie Jian
Published: September 2023

Two large barriers are impeding the wide implementation of battery electric vehicles, namely driving-range and cost, primarily due to the low specific capacity/energy and high cost of mono-valence cathodes (e.g. LiNi0.8Co0.1Mn0.1O2) used in lithium-ion batteries. Iron is the ideal element of choice for cathode materials considering its abundance, low cost and toxicity. Two fundamental challenges, in particular, the poor reversibility of (de)lithiation and low electronic conductivity, prevent those iron based high specific capacity/energy multi-valence conversion cathodes from practical applications. In this work, we have developed a sustainable FeOF nanocomposite with extraordinary performance. In particular, we were able to reach the theoretical specific capacity of 621 mAh·g-1 and 1,124 Wh·kg-1 specific energy (2.1-valence change/2.1 Li+ stored per unit) and more than 100 cycles with 80% capacity retention at 0.1C (realizing the reversible (de)lithiation), which is 3 times of the specific capacity, and 2 times of the specific energy of current mono-valence intercalation LiCoO2 respectively (i.e., 145 mAh·g-1 and 551 Wh·kg-1). This is the result of an effective approach, combing the nanostructured FeOF with graphene sheets to solve these challenges, realized by (1) making the (de)lithiation reversible by immobilizing FeOF nanoparticles and the discharge products of Fe nanoparticle and LiF over the graphene surface, and sandwiching them between graphene sheets to prevent them from migration and dissolution into electrolytes and (2) providing the inter-particle electric conductivity. In situ high energy synchrotron X-ray absorption spectroscopy (XAS) reveals that this new FeOF composite has a different but reversible (de)lithiation mechanism. Importantly, it demonstrated that introducing small amount of graphene can create new materials with desired properties, opening a new avenue for altering the (de)lithiation process. Such extraordinary performance represents a significant breakthrough in developing the sustainable conversion materials for replacing the intercalation compounds, eventually overcoming the driving range and cost barriers.
Critical Barriers to Successful Implementation of Earth-Abundant, Mn-Rich Cathodes: Low SOC Impedance
Authors: Chen Jiajun , Gutierrez Arturo , Saray Mahmoud Tomadoni , Shahbazian-Yassar Reza , Balasubramanian Mahalingam , Wang Yan , Croy Jason R
Published: September 2023

The ever-growing demand for electric vehicles and grid storage systems has pushed the development of sustainable cathode materials for Li-ion batteries. Lithium- and manganese-rich (LMR) oxides are a promising class of cathode materials in this regard because of their high capacities/energies and reliance on low-cost, earth-abundant manganese (>50%). However, several outstanding issues remain that hinder the performance of these cathodes. While the mechanisms of the now well-known phenomena of voltage fade, hysteresis, and oxygen activity have been intensively studied, relatively little attention has been given to understanding the impedance characteristics of LMR electrodes. Specifically, the anomalous rise in area specific impedance (ASI) at low states-of-charge (SOCs), and the overall impedance rise on extended cycling due to surface issues, are critical barriers to implementation that still need to be further understood and mitigated.

This presentation will discuss a comprehensive study at Argonne National Laboratory on understanding impedance behavior in cobalt-free, LMR cathode-electrodes. In this study, we use a unique surface-treatment/electrolyte-additive combination that allows us to separate the major contributions of bulk and surface to the impedance behavior over long-term cycling. The results indicate that the anomalous rise in impedance at lower SOCs is directly associated with the correlated, bulk processes of voltage fade and voltage hysteresis. A conceptual model is presented to understand the impedance behavior of these complex materials.
How Graphite Particle Sizes Affect Fast Charging Performance of Ultra-Thin Layer Electrodes for Li- Ion Batteries
Authors: Luo Mei , Wang Guanyi , Mijailovic Aleksandar S , Yang Jian , Sheldon Brain W. , Wu Qingliu , Lu Wenquan
Published: September 2023

Extreme fast charging (XFC, ≤15 min) of lithium-ion batteries is highly desirable to accelerate mass market adoption of electric vehicles.[1] However, great capacity fading, as well as safety issues due to the lithium plating, limit its implementation. In this study, we investigated the fast-charging capability of graphite materials with various particle sizes under different charging currents up to 6C. To eliminate Li+ ion gradients effects across the thickness of electrode[2], ultra-thin layer graphite electrodes were developed to investigate the “real" fast-charging capability of graphite at particle level by assessing its lithium plating limit. Observations derived from the electrochemical results as well as microscopy characterization revealed that smaller particles exhibited a superior fast-charging performance including better capacity reversibility, less polarization and less lithium plating. Moreover, smaller particles are observed to be able to handle higher C rate charging without Li plating, graphite electrodes with particle size of ~5μm can be safely charged to 80% SOC at 4C. While with particle size of ~15 μm, Li plating occurred on the graphite electrode at 2C. According to pseudo-2-dimensional (P2D) model, the superiority of the small particles might be due to the faster diffusion and intercalation through the particle because of their smaller size and faster rate kinetics due to their larger surface area. This work can help us to better understand the fast-charging behavior and provide the guidance to design the optimum electrode architecture for high-rate of lithium-ion batteries.

Keywords: Ultra-thin electrode, Graphite Electrode, Particle Size, Fast Charging, Li-Ion Batteries

[1] D. Howell et al., “Enabling Fast Charging: A Technology Gap Assessment,” 2017.

[2] K. P. C. Yao, J. S. Okasinski, K. Kalaga, I. A. Shkrob, and D. P. Abraham, “Quantifying lithium concentration gradients in the graphite electrode of Li-ion cells using operando energy dispersive X-ray diffraction,” Energy Environ Sci, vol. 12, no. 2, pp. 656–665, Feb. 2019, doi: 10.1039/C8EE02373E.
(Keynote) Inferring Degradation Modes from Battery Cycling Data
Authors: West Alan , Mayilvahanan Karthik , Hui Zeyu , Takeuchi Esther S. , Marschilok Amy C.
Published: September 2023

Battery research and development efforts necessarily involve large-scale experimental studies where cells are cycled under different conditions. Physics based models (PBM) of the type pioneered by John Newman, Ralph White, and others can play a key role in interpreting the resulting cycling data, and of course can be used to improve performance by modifications of cell design to optimize for a specific application.

Long-term studies that characterize degradation in cell performance are an important type of cycling experiment that can be used to estimate useful battery life in a real-world application. The establishment of correlations between duty cycle and life is valuable and can inform battery management systems with a goal to extend life. During the course of such experiments, large data sets are created and we explore how a PBM might be used to infer the modes of cathode degradation. From degradation modes, mechanisms of degradations might be hypothesized, and this may lead to insights to further improve design and operation.

Here, two PBM are reformulated to determine how cell parameters such as the amount of active cathode material appears to change with cycle number. Parameter estimation is applied to cycling data, and parameter changes are tracked for cycling data at different C-rates and different cutoff voltages. Parameter estimates are challenged with complementary experimental data for NMC and for a second cathode material that has been characterized extensively. The comparisons suggest that the methodology is effective and can provide physical insights into degradation mechanisms.

To facilitate the “workflow,” inverse surrogate machine-learning techniques, in which simulation data are used for training neural networks to rapidly estimate parameters from experimental data, were utilized. To allow for both imperfect PBM and for non-ideal experimental data, data augmentation methods were introduced to improve the accuracy of parameter estimation algorithms. Examples are shown, with an emphasis on the physics over the mathematics and with an eye towards next steps.
Simulation-Driven Enhancement of an Alkaline CO2 Capture Electrochemical Cell
Authors: Masiello Davide , Gubler Lorenz , Muroyama Alexander
Published: September 2023

Electrochemical cells using anion exchange membranes (AEM) have been previously demonstrated to regenerate aqueous K2CO3 solutions obtained via CO2 absorption from air with aqueous KOH [1]. Preliminary results suggest this technique might significantly outperform currently employed methods in terms of specific energy expenditure (MJ/kgCO2). In order to accomplish this, we propose a computational study of an electrochemical cell designed and operated at the Paul Scherrer Institut. A multi-phase multi-component model has been developed and implemented via appropriate customization of the commercial CFD software Ansys Fluent. The model accounts for all the physical and chemical phenomena relevant to the electrochemical process, i.e. fluid flow mechanics, heat and mass transfer, electrical potential propagation and chemical and electrochemical reactions. The results of the simulations suggest two possible causes of cell overpotential. Firstly, the formation of hydrogen bubbles by the hydrogen evolution reaction in the cathode electrode, which partially cover the liquid-solid interface where the electrochemical reaction occurs. This is clearly shown by direct comparison with idealized single-phase simulations. Secondly, the flow structure of the catholyte is not optimized to favor the diffusion/migration of carbonate rather than hydroxide anions towards the membrane. This requires increasing the gap between the electrode and the membrane in order to maximize the faradaic efficiency, but it also increases the cell specific resistance. Although we show that there exists an optimal ratio of electrode-membrane gap to cell height, our simulations indicate that a topological optimization of the electrode fine structure might be beneficial to eliminate the undesired effects mentioned above.

[1] Muroyama, A. P., & Gubler, L. (2022). Carbonate Regeneration Using a Membrane Electrochemical Cell for Efficient CO2 Capture. ACS Sustainable Chemistry & Engineering.
Multiphysics Modeling of Solid Oxide Iron Air Battery with New Catalyst and Proton Conductor Oxide Support
Authors: Morey Chaitali , Tang Qiming , Jin Xinfang , Huang Kevin
Published: September 2023

Long-duration energy storage (LDES) (10+ hours) is widely regarded as an enabling technology to deepen the penetration of renewable energy into the commercial utility market. However, the current storage technologies cannot achieve LDES’s duration requirement at a competitive cost. Therefore, new LDES technologies are highly sought after in recent years. Solid oxide iron air battery is a newly emerging battery based on oxide-ion chemistry and stores energy in energy-dense solid iron. Our recent results have shown that the battery in a laboratory size (f1”) delivers 12.5-hour storage per cycle for 20 cycles with high energy capacity and round-trip efficiency. This presentation focuses on the description of a high-fidelity 2D axis symmetrical multi-physics model to simulate the performance of a solid oxide iron air battery. The model battery system consists of an anode-supported solid oxide cell and energy storage unit (ESU) of iron bed with a proton conducting oxide BaZr0.4Ce0.4Y0.1Yb0.1O3 (BZC4YYb) based support and iridium as a catalyst. The Multiphysics model encompasses charge transfer, mass transport, and chemical redox kinetic cycle occurring across all components of the battery and is validated with experimental results. The kinetic JMA (Johnson-Mehl-Avrami) model is used for describing the oxidation and reduction kinetics of Fe-BZC4YYb-IrO2 ESU. The motivation for combing the Ir catalyst with proton conductor oxide support in ESU is to boost the sluggish FeOx reduction kinetics. Compared to the baseline ESU, i.e. Fe2O3/ZrO2, the newly developed BZC4YYb-IrO2 shows great catalytic activity toward FeOx reduction, thus allowing SOIAB to operate at 500-550oC with excellent capacity, stability, and high round trip efficiency. The presentation will also show the experimental data of improved reduction kinetic rate of Fe-BZC4YYb-IrO2 over the baseline Fe2O3/ZrO2.
Strategies of Practical Implementation of Chemical Pre-Lithiation Using Lithium Arene Complex Solutions: A Systematic Study on Silicon-Based Anodes
Authors: Frankenstein Lars , Mohrhardt Marvin , Peschel Christopher , Gomez Martin Aurora , Placke Tobias , Kasnatscheew Johannes , Winter Martin
Published: September 2023

Currently, Lithium ion batteries (LIBs) are state-of-the-art (SOTA) energy storage systems. There is an urgent need for further improvements in terms of gravimetric and volumetric energy of LIBs, for a successful market penetration of electric vehicles. Therefore, development of advanced negative electrode materials is of high interest. Here, silicon (Si) is a promising active material to replace SOTA graphite due to its ~10-fold higher specific capacity and being also high abundant.

However, Si undergoes severe volume changes up to 280% during (de-)lithiation, resulting in fast capacity fading and short cycle life due to the continuous re-formation of the solid electrolyte interphase (SEI), leading to active lithium losses (ALL). In order to counteract ALL, research is focusing on suitable pre-lithiation processes. Among different pre-lithiation methods, chemical pre-lithiation by application of lithium arene complex (LAC) solutions is promising as it is a fast, easy and cost-effective method.

In this work, the stability of three different solvents to produce a 4,4’-dimethylbiphenyl (4,4’-DMBP) LAC is investigated via solid phase microextraction gas chromatography-mass spectrometry method (SPME-GC-MS). The optimized LAC solution is used to evaluate the stability of different binder systems with respect to electrode manufacturing. Based on these fundamental insights, different parameters such as the reaction temperature (T) and pre-lithiation time (PL-t) are systematically investigated regarding suitable degrees of pre-lithiation (DOPL) of the negative electrode. DOPLs up to a plateau of 55% can be obtained by using 0.5 M 4,4’-DMBP in tetrahydrofuran (THF) as LAC solution. Higher temperature during the reaction reduces the PL-t until achieving a pre-lithiation plateau. The impact of the parameters T and PL-t towards the electrochemical performance of Si-based LIB full cells is thoroughly investigated. It is shown that this approach improves the cycle life of a silicon nanowire graphite composite negative electrode up to 600% compared to the pristine electrodes