bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling Thermal Runaway of Large Format All-Solid-State Lithium Metal Cells during a Thermal Ramp Test and Short Circuit: Sensitivity Analysis and Reaction Pathways
Authors: Johnson Nathan B , Albertus Paul
Published: November 2022

While high-energy batteries with an inorganic solid electrolyte may offer improved safety compared with current Li-ion cells because of the lack of a flammable liquid electrolyte, this is a topic that requires careful analysis. In our past work we modeled an LiyCoO2|LLZO|Li large format cell in a thermal ramp test and with a short circuit in a portion of the cell that led to thermal runaway of the entire cell.1 In the present talk we explore several key sensitivities and limitations in our large-format solid state cell model, those sensitivities include the specific energy, electrode capacity ratio, heat transfer to the surroundings, kinetic parameters for key exothermic reactions (e.g., Li2O formation), and others. Our previous modeling work also only considered the potential reaction of lithium metal with oxygen released from the cathode, as the differential scanning calorimetry (DSC) data on which our model was built did not include other cell reactions.2 In the present talk we also present results with an expanded kinetic model to include processes such as lithium/current collector alloying, oxidation of binder, oxidation of conductive carbon, and reaction of lithium with other gaseous products. The impact of modifying our baseline model parameters, and adding additional reactions, on the onset temperature for thermal runaway, the maximum heating rate, and the maximum temperature reached during thermal runaway.

References:

(1) Johnson, N. B.; Albertus, P. Modeling thermal behavior and safety of large format all-solid-state lithium metal batteries under thermal ramp and short circuit conditions. Submitted.
2022.

(2) Inoue, T.; Mukai, K. Are All-Solid-State Lithium-Ion Batteries Really Safe?−verification by Differential Scanning Calorimetry with an All-Inclusive Microcell. ACS Appl. Mater. Interfaces
2017, 9 (2), 1507–1515.
Reevaluate the Electrochemical Stability of Low Concentration Ether Electrolyte in Lithium Metal Batteries
Authors: Liu Junxiang , Fang Chengcheng
Published: November 2022

Ether based electrolytes are essential to enable stable lithium metal batteries. Low concentration electrolyte composed with 1M lithium bis(fluorosulfony)imide (LiFSI) and 1,2-dimethoxyethane (DME) is alluring due to low viscosity and superior ion conductivity. Although lower salt concentration is desirable to reduce cost, it is believed that low concentration ether electrolyte cannot sustain more than 4V, diminishing their application in high-voltage batteries. Here, we report that the measured electrochemical stability window (ESW) of low concentration 1M LiFSI/DME electrolyte is largely affected by working electrode (WE). The measured ESW extends to ~4.4 V with aluminum WE compared with less than 4V with stainless steel WE. Furthermore, we demonstrate that Li||LiNi0.8Co0.1Mn0.1O2 battery can operate in 1M LiFSI/DME electrolyte at 4.2 V with long calendar life (97% capacity retention after 100 cycles) under high areal capacity (2.5 mAh/cm2) and low N/P ratio (~2:1). This work opens avenue for low concentration electrolyte applying in high-energy and cost-efficiency batteries.
Interfacial and Charge-Transport Impedances of NCM Composite Cathodes with Halide Solid Electrolytes for All-Solid-State Batteries
Authors: Yun Jonghyeok , Cha Hyohyun , Kim Siwon , Kim Beomsu , Lee Jong-Won
Published: November 2022

All-solid-state batteries (ASSBs) offer a fundamental solution to mitigate the safety and reliability issues of conventional lithium-ion batteries utilizing flammable liquid electrolytes. However, interfacial resistances between the cathode materials and solid electrolytes, which originate from poor solid-solid contacts and detrimental interfacial reactions, limit the electrochemical performances of ASSBs. Recently, various approaches have been developed to realize high-capacity composite cathodes with improved cycling stability. For example, single-crystal LiNi0.8Co0.1Mn0.1O2 (NCM811) has been reported to mitigate the capacity fading resulting from cracking of commonly adopted multi-crystal NCM811. Also, halide-type solid electrolytes are reported to exhibit high Li-ion conductivity and electrochemical stability with NCM. In this work, we systematically study the interfacial and charge-transport impedances of NCM composite cathodes with halide solid electrolytes. The composite cathodes comprising single- or multi-crystal NCM811 and Li6PS5Cl or Li3InCl6 (and conductive agents) are fabricated to characterize their electrochemical impedance behaviors. In particular, we analyze the evolution of the interfacial and charge-transport impedances during charge–discharge cycling based on a multi-rail transmission line model combined with interfacial reactions. In addition, we investigate the chemical, electrochemical, and mechanical degradations of composite cathodes using various analytical tools to elucidate performance-determining factors of ASSBs.
(Digital Presentation) Development of Bifunctional Oxygen Electrocatalysts for Electrically Rechargeable Zinc-Air Batteries
Authors: Mathialagan Kowsalya , T Saranya , Surendran Ammu , Dixon Ditty , S.T. Nishanthi , Bhaskar Aiswarya
Published: November 2022

Zinc-air battery is a promising battery system as it possesses high theoretical energy density and is cost-effective3. The theoretical energy density of a Zinc-air battery is 1086 Wh kg-1, which is five times greater than that of lithium-ion batteries2. Moreover, zinc metal is one of the most abundant metals in the earth’s crust and is inexpensive. Rechargeable metal-air batteries operate based on two fundamental electrochemical reactions as Oxygen Reduction Reaction (ORR) during discharge and Oxygen Evolution Reaction (OER) during recharge processes, respectively3. Electrocatalytic activity of the bifunctional electrocatalyst towards these two oxygen reactions will decide the performance of the battery1. Recent advancements in catalyst development are the fabrication of rechargeable air electrodes using a single active material that is capable of bifunctionally catalyzing ORR and OER3. The development of bifunctional catalysts with high activity is necessary for rechargeable metal-air batteries, such as zinc-air batteries3.

In this work, a perovskite-type LaFeO3 material was synthesized using a citric acid-assisted sol-gel method and is investigated as bifunctional oxygen electrocatalyst for electrically rechargeable zinc-air batteries. Structural studies using X-ray diffraction revealed the formation of phase pure LaFeO3 in space group Pbnm. This catalyst displayed considerable bifunctional catalytic activity for both oxygen reduction (0.74 V vs. RHE) and oxygen evolution reactions (0.40 V vs. RHE at 10 mA cm-2) in 1 M KOH electrolyte. Electrically rechargeable zinc-air batteries assembled using LaFeO3 as the oxygen electrocatalyst deliver a specific capacity of 936.38 mAh g(
Zn)
-1 after the 1st discharge. Further details will be discussed in the poster.

Financial support from Department of Science and Technology, Govt. of India under research grant number DST/TMD/MECSP/2K17/20 is gratefully acknowledged.

References:

[01] Y. Li, M. Gong, et. al., Nature communications, 4, (2013), 1-7

[02] P. Gu, M. Zheng, et. al., Journal of Material Chemistry, (2017), 1-17

[03] D. U. Lee, P. Xu, et. al., Journal of Material Chemistry, 4, (2016), 7107-7134
From an Engineer's Perspective: Evaluation of the Invested Effort and the Resulting Benefits of Artificial Neural Networks in Proton Exchange Membrane Water Electrolysis Development
Authors: Rex Alexander , Trinke Patrick , Eckert Christoph , Bensmann Boris , Hanke-Rauschenbach Richard
Published: November 2022

Machine learning approaches have become increasingly important in engineering research and development in recent years, and the first steps in this field can also be found at proton exchange membrane water electrolysis (PEMWE) development [1]. Well-known conventional simulation models for engineers are usually based on physical and empirical equations, with different approaches depending on the desired model depth. However, especially for the simulation of complex processes, model formulation and parametrization with sufficient accuracy are often challenging, with these types of models reaching their limits. In contrast, data-driven models use machine learning approaches to reproduce the desired processes based on large data sets and do not require physical or empirical model formulations [2]. For decision making on the deployment of machine learning methods, the effort required for familiarization, conceptual design, and implementation is the crucial aspect to answering the question of beneficial gain. Our conference contribution aims to answer these questions regarding invested effort and resulting benefit through a self-experiment using the example of artificial neural networks (ANN) in PEMWE research. It is intended to guide engineers interested in machine learning methods without prior knowledge, addressing their questions and ultimately assisting them in decision-making.

Our proposed research is shown in Figure 1 and consists of conceptualizing and programming ANN for two application cases, one for high-frequency resistance (HFR) regression and the other for PEMWE single-cell aging prediction. Here, the processes of familiarization time, conceptualization, and implementation of ANN are transparently presented from an engineer's perspective. The modeling results are evaluated in terms of their utility to the user. The data sets for training and validating the ANN to calculate HFR are generated using a physics-based simulation model. For aging prediction, the datasets are based on experimental data obtained from accelerated stress tests (AST) of a PEMWE single cell.

Our contribution finalizes with an assessment of the profit growth of engineering applications for pioneers in the field of machine learning methods.

Figure 1. Scheme for the evaluation of PEMWE single cells by artificial neural networks from an engineering perspective.

References:

[1] Bensmann, B., et al. "An engineering perspective on the future role of modelling in proton exchange membrane water electrolysis development." Current Opinion in Chemical Engineering (2022) (accepted)

[2] Mistry, A., et al. "How machine learning will revolutionize electrochemical sciences." ACS energy letters 6.4 (2021): 1422-1431.

Figure 1
Anode Catalyst Durability and Accelerated Stress Tests in Proton Exchange Membrane-Based Low Temperature Electrolysis
Authors: Alia Shaun M , Reeves Kimberly S. , Yu Haoran , Kropf A. Jeremy , Kariuki Nancy N. , Park Jaehyung , Myers Deborah J. , Cullen David A.
Published: November 2022

Hydrogen has unique advantages as an energy carrier, with a high energy density and abilities for long term storage and conversion between electricity and chemical bonds. Although hydrogen currently has a significant role in transportation and agriculture, its use in energy consumption overall has been limited, particularly in the case of electrochemical water splitting. With decreasing electricity prices, electrolysis cost reductions can be achieved and allow for an opportunity for greater use.(1) While load-following renewable power sources can reduce feedstock cost, further cost reductions can be achieved by reducing the platinum group metal (PGM) content.(2) Efforts are needed to understand and mitigate electrolyzer degradation, particularly when accounting for lower PGM loadings and intermittent operation.

In this presentation, studies related to anode catalyst durability will be discussed and include the impact of individual stressors, observed degradation mechanisms, and the development of catalyst-specific accelerated stress tests. Membrane thickness and ohmic losses were deconvoluted from catalyst layer durability experiments, allowing for a transition from potential-driven parametric observations to current-driven stress tests for advanced materials and coating processes. Expanded studies have incorporated advanced materials, including higher surface areas, different oxide compositions, supports, and multicomponents. Kinetic improvements were found to lessen load requirements and can mitigate catalyst loss. Cell performance loss during extended operation, however, tended to qualitatively correspond to ex-situ dissolution rates and less stable materials accelerated catalyst layer thinning, migration into the membrane, and interfacial tearing. Perspectives on anode catalyst development will be discussed and increasing site-access and utilization further into the catalyst layer is needed to better understand the role of advancements in mitigating electrolyzer durability losses.

[1] B. Pivovar, N. Rustagi and S. Satyapal, The Electrochemical Society Interface, 27, 47 (2018).

[2] K. Ayers, N. Danilovic, R. Ouimet, M. Carmo, B. Pivovar and M. Bornstein, Annual Review of Chemical and Biomolecular Engineering, 10, 219 (2019).

[3] Electron microscopy was performed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.
Advanced Porous-Transport-Layer Interface Design for PEM Electrolyzers
Authors: Lee Keonhag Keonhag , Tricker Andrew W. , Peng Xiong , Danilovic Nemanja , Weber Adam Z.
Published: November 2022

Proton-exchange-membrane (PEM) water electrolyzers are promising technologies for generating clean hydrogen for use in a variety of sectors. The anode catalyst layer/porous-transport layer (CL/PTL) interface plays a vital role in determining performance of proton-exchange-membrane (PEM) water electrolyzers. This interface impacts ohmic, kinetic, and mass-transport overpotentials experienced by the cell. PTLs with large surface pores cause undesired catalyst layer deformation into pores of the PTL, which exacerbates degradation, and leads to high ohmic and kinetic overpotentials due to insufficient interfacial contact area.1,2 On the other extreme, low surface porosity at the interface leads to accumulation of oxygen gas that inhibit water transfer, resulting in mass-transport overpotentials.3 Thus, ideal PTLs should have hierarchical structure with high bulk porosity and low tortuosity to mitigate mass-transport overpotentials, while low surface porosity is need to enhance interfacial contact area. In this talk, we explore controlling the interfacial pore structure of these layers through a subtractive method, namely, laser ablation. Laser ablation is a facile method for tailoring the interfacial pore structure of PTLs. Heat from the laser melts titanium, granting a unique morphology advantageous to electrolyzer performance. Laser-ablated PTLs provide improved contact with the CL, while maintaining the bulk pore structure elsewhere, thereby facilitating gas removal and water transport. We also examine how laser-modified PTLs can help enable ultra-low catalyst loadings by minimizing interfacial contact resistance with the thinner catalyst layers. Overall, our work reveals that laser ablation is a facile method to enhance PEM electrolyzer performance.

Acknowledgements

This work was funded under the H2NEW Consortium by the Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office, of the U. S. Department of Energy under contract number DE-AC02-05CH11231. References

T. Schuler, R. De Bruycker, T. J. Schmidt, and F. N. Büchi, J. Electrochem. Soc., 166, F270–F281 (2019)

T. Schuler, T. J. Schmidt, and F. N. Büchi, J. Electrochem. Soc., 166, F555–F565 (2019).

X. Peng et al., Adv. Sci., 8 (2021).
(Invited) Bipolar Membranes with a 3D Junction of Interlocking Electrospun Fibers
Authors: Yang Zezhou , Wycisk Ryszard , Pintauro Peter N.
Published: November 2022

Bipolar membranes (BPMs), typically laminated layers of anion-exchange and cation-exchange polymers, have the unique capability of splitting water at a potential near 0.83 V. Such membranes are used in electrodialysis membrane separation processes. They also have applications in water electrolyzers, CO2 electrolysis cells, and self-humidifying fuel cells. We report here on recent developments regarding BPMs with a high interfacial area, 3D nanofiber junction.

Membranes were prepared by first creating a bipolar junction layer, by the simultaneous electrospinning of anion-exchange and cation-exchange polymers, with the addition of catalyst nanoparticles to facilitate water splitting. Solvent vapor exposure and hot-pressing closed all interfiber pores, to create a dense film of interpenetrating and interlocking nanofibers of positively and negatively charged polymers. In one fabrication method, dense films of solution cast anion and cation-exchange polymers were hot-pressed onto the opposing surfaces of the junction layer to create a tri-layer BPM. Membranes were also fabricated by electrospinning all three layers of the BPM: first spinning anion-exchange fibers, followed by dual fiber spinning with catalyst spraying, and then spinning only cation-exchange fibers. Solvent exposure and hot-pressing closed all interfiber voids.

BPMs were made with a junction layer 12-15 mm thick, where the total membrane thickness was 50-80 mm. Membranes were prepared with both hydrocarbon and fluoropolymer ionomers, e.g., sulfonated poly(ether ether ketone) or perfluorosulfonic acid as the cation-exchange polymer and either quaternized poly(phenylene oxide), AEMIONä (an imidazolium-based polymer sold by Ionomr Innovations, Inc.), or PiperION (a poly(aryl piperidinium) from Versogen) as the anion-exchange polymer. A variety of different junction layer catalysts powders were examined, including Al(OH)3 and graphene oxide. Membranes were evaluated in an H-cell for the collection of steady-state current-voltage data and in a flow cell for long-term constant current water splitting (electrolysis) operation, typically with an aqueous Na2SO4 electrolyte. The 3D junction membranes performed exceptionally well: (i) the water splitting potential was low (near the expected value of 0.83 V), (ii) the transmembrane voltage drop was small at high currents (e.g., a voltage drop of 1.1 V up to 1.1 A/cm2), and (iii) the extended bipolar reaction zone for water splitting with interlocking fibers allowed for high current density operation with no evidence of membrane degradation.

In this talk, the effect of membrane composition (the type/amount of anion and cation exchange polymers and choice of catalyst) and structure (the thickness of the layers) on short-term and long-term membrane performance will be discussed. Results will be presented for operating the bipolar membrane in water splitting and water generation modes.
(Digital Presentation) Oxygen Evolution Reaction in Ru1-XMxO2 (M = Ti, Zr, Nb, Ta, Cr) Doped Catalysts: Activity and Stability Effects
Authors: Ospina Acevedo Francisco A , Balbuena Perla B. , Godinez Salomon Jose Fernando , Albiter Luis A , Bailey Kathleen O. , Naymik Zachary G. , Rhodes Christopher P.
Published: November 2022

The complex reaction mechanisms and dissolution pathways that drive oxygen evolution reaction on metal and metal oxide surfaces under acidic conditions challenge the development of a highly active, highly stable, and low cost catalyst for proton-exchange membrane (PEM) water electrolyzers. Currently, ruthenium-based materials present lower overpotentials, lower cost and higher global supply compared to iridium-based materials, though they are also considerably less stable. In order to elucidate a way to improve RuO2 stability under the harsh conditions during water electrolysis, we use a density functional theory (DFT) approach to investigate the effects on catalyst structure, OER activity and stability of transition metal substitution within Ru1-xMxO2 (M = Ti, Zr, Nb, Ta, Cr) at different atomic concentrations. Calculations show that M substitution within rutile RuO2 affects the electronic structure resulting in regions of electron accumulation and depletion at the surface and shifts the Ru d-band and O2p band centers, which are highly dependent on dopant characteristics and doped site. Moreover, dissolution calculations on the Ru1-xTixO2 surfaces show that Ti substitution alter the metal dissolution pathway energetics and thermodynamics bringing stability to the catalyst in terms of reducing material loss. Theoretical XRD patterns, Ru d-band and O p-band center calculations, and activation and reaction energy trends are in excellent agreement with experimental results that includes X-ray diffraction analysis, high resolution transmission electron microscopy images, X-ray photoelectron spectroscopy of core and valence bands, and rotating disk electrode measurements. In this presentation, we focus on the theoretical and computational aspects. The evaluation of the thermodynamics and kinetics of the water splitting, and oxygen evolution mechanism is done with spin-polarized plane-wave DFT calculations, while Ab Initio Molecular Dynamics (AIMD) simulations allow following and complementing the understanding of the dynamics of the initial steps of water dissociation on the various M and Ru sites. Electronic structure changes on the surface due to the presence of M before and during the reaction are analyzed based on the density of states and local magnetic moments, and the activation energies are obtained from the climbing Nudge Elastic Band method. Dissolution calculations are carried out with constrained-AIMD simulations using the slow-growth approach within the “Bluemoon ensemble” as implemented in VASP.
(Invited) Alkaline Membrane Electrolyzers: Catalysts, Degradation Mechanisms, and Materials Engineering for Performance and Durability
Authors: Boettcher Shannon W. , Lindquist Grace , Krivina Raina A , Kwak Minkyoung
Published: November 2022

Commercialized membrane electrolyzers use acidic proton exchange membranes (PEMs). These systems offer high performance but require the use of expensive precious-metal catalysts such as IrO2 and Pt that are nominally stable under the locally acidic conditions of the ionomer. Alkaline-exchange-membrane (AEM) electrolyzers in principle offer the performance of commercialized PEM electrolyzers with the ability to use earth-abundant catalysts and inexpensive bipolar plate materials. I will present our fundamental work in understanding earth-abundant water-oxidation catalysts, including the use of integrated reference-electrode device architectures and cross-sectional materials analysis, as well as progress in building high-performance AEM electrolyzers. Baseline systems operate at 1 A·cm-2 in pure water feed at < 1.9 V at a moderate temperature of ~70 °C using either IrO2 or Co3O4 anode catalyst layers, PiperION alkaline ionomers, and stainless steel porous transport layers. These devices, however, degrade rapidly compared to PEM electrolyzers. The voltage profile corresponding to degradation has intial fast (~10 mV/h) and steady-state slow components (~1 mV/h), which we link to chemical and structural changes in the ionomer catalyst reactive zone. I will discuss these processes in electrolyzer devices and in model systems that are correlated with this performance loss, as well as present promising new strategies we have developed to mitigate degradation using novel ionomers and electrode catalyst compositions and architectures.

Figure 1
Engineering of Electrodes and Operating Conditions for Pure-Water-Fed Anion Exchange Membrane Water Electrolyzers
Authors: Bohannon Jasmine , Duanghathaipornsuk Surachet , Ul Hassan Noor , Divekar Ashutosh , Zulevi Barr , Kohl Paul , Mustain William Earl
Published: November 2022

Many industrial processes such as petroleum refining, ammonia production, and metal refining have hydrogen gas as a feedstock. Hydrogen gas can be produced via fossil fuel reforming, photo-electrochemical conversion, thermochemical water decomposition, as well as water electrolysis. Among the various water electrolysis technologies, anion exchange membrane water electrolyzers (AEMWEs) possess possible qualities that will allow for them to out-compete incumbent alkaline electrolyzers and proton exchange membrane electrolyzers PEMWEs). AEMWEs have to possibility to combine platinum group metal–free (PGM-free) catalysts, low-cost cell components and operation at high pressure. It is also desirable for AEMWEs to be operated with a pure water feed, high performance and long life – all of which has been elusive thus far.

In this presentation, we will demonstrate device engineering pathways to achieve high performance with pure-water-fed AEMWEs. This was accomplished by optimizing the type and amount of electrocatalyst on both anode and cathode alongside the flow conditions and operating temperature. The optimized pure-water-fed AEMWEs have been successfully operated at steady-state at a voltage below 1.90 V at 1.0 Acm-2 at 80 °C. Differences will be highlighted between DI water and electrolyte-fed systems. The importance of pre-treatment to ensure pure DI-water operation will also be discussed. This work emphasizes the importance of engineering electrodes and operating conditions to reach the highest performance of pure-water-fed AEMWEs, which is expected to allow these devices to out-compete existing water electrolysis technologies.
PGM-Free AEM Electrolyzer Cell Development for Solar Power Integration
Authors: Zhong Sichen , Lattimer Judith , Strasser Derek James , McKone James , Kaur Manjodh , Hu Keda , Yan Yushan
Published: November 2022

The increasing availability of renewable energy sources, especially solar power, coupled with the desire to reduce greenhouse gas emissions, has led to an increased interest in using renewables to satisfy global energy demand. Hydrogen is an attractive alternative to fossil fuels due to its potential for emissions reductions and advantages in storage and transportation. Direct solar-to-hydrogen generation would enable the conversion of renewable energy and water into a storable fuel, thereby drastically reducing carbon emissions. However, current hydrogen production from commercial PEM electrolysis systems requires acidic environment which necessitates the use of expensive platinum group metal (PGM) catalysts and corrosion resistant cell stack components. Thus, a stable, robust, and inexpensive anion exchange membrane and PGM-free catalysts are needed to make alkaline solar water splitting commercially viable as a replacement for the expensive PEM system.

We have developed a fully PGM-free electrolyzer using anion exchange membrane (AEM) in an alkaline environment that operates at 80 °C. Using carbon supported NiMo as hydrogen evolution reaction (HER) catalyst and NiFe as oxygen evolution reaction (OER) catalyst, in combination with commercially available AEM from Versogen, we were able to achieve a stable performance of 1.504 V at 100 mA/cm2, compared with baseline PGM cell at 1.508 V, in alkaline environment. At 2 A/cm2, the fully PGM-free cell demonstrated 200 mV higher potential compared to the PGM baseline cell at 2.009 V. Furthermore, we were able to run more than 200-hour at constant current density 2 A/cm2, with 85 mV performance loss. Further developments in catalyst performance and membrane stability, as well as integration with photovoltaics to enable hydrogen production from water, are underway.

Acknowledgement: The project is financially supported by the Department of Energy’s Office of Science under the Grant DE-SC0020576
High Performance Separator and Hydrogel Based on Aramid Fibers for Zn Ion Batteries
Authors: Wang Peng , Andrei Petru
Published: November 2022

Aqueous zinc-ion batteries (ZIBs) have received much attention recently because they are environmentally friendlier, safer, and cheaper than the current Li-ion batteries. Rechargeable ZIBs are not only regarded as promising alternative energy storage systems, but have the potential to replace Li-ion batteries in many applications. Unfortunately, the formation of the dendrites on the Zn anodes, hydrogen evolution and side reactions are overwhelming challenges for the commercialization of ZIBs. Conventional strategies often focused on anode protection and the design of the electrolyte additive, but neglected the importance of the separator. In this presentation, a uniform porous separator constructed from the commercial material Kevlar (para-aramid), a type of strong synthetic fiber, was developed for aqueous ZIBs. Derived from the high-strength aramid, the separator demonstrated excellent tensile strength compared to the conventional glass fiber separators. Therefore, the developed separator shows good protection to the Zn anode by preventing Zn dendrite growth and prolonged the lifetime of the Zn symmetric cell. In addition, aramid fiber was used to construct an anti-freeze hydrogel for aqueous ZIBs, which played the roles of both separator and electrolyte. The hydrogel could significantly inhibit zinc dendritic growth and other side reactions even when operating below 0 °C. When paired with a MnO2 cathode, the hydrogel based cell shows excellent electrochemical performance in a wide range of temperatures. This work opens a gate for the development of separators and hydrogel electrolytes based on aramid fibers.
Electrochemical and Structural Study on PVDF-Based Polymer Electrolytes for Solid-State Batteries
Authors: Yen Dean , Tan Sha , Yang Xiao-Qing , Chen-Wiegart Yu-chen Karen , Hu Enyuan
Published: November 2022

Lithium-ion batteries are widely used today in powering devices from portable electronics to electric vehicles. Despite their great success, this battery chemistry relies on organic solvent-based liquid electrolytes which are highly flammable, leading to major safety concerns. In contrast, solid-state batteries, which are based on solid-state electrolytes, are regarded to have much better safety characteristics and potentially higher energy density than the conventional lithium-ion batteries. Solid-state electrolytes usually include ceramics, polymers, gels, and composites. Among them, polymer materials have attracted considerable attention due to their great interfacial contact, flexibility, and easy fabrication. In particular, polyvinylidene fluoride (PVDF) polymer electrolyte is a promising candidate as it can potentially provide a high voltage window and enable high energy density solid-state batteries. However, the current PVDF-based polymer electrolyte is still not compatible with high voltage cathodes, such as layered lithium transition metal oxides and the interaction between the salt and PVDF polymer has not been fully elucidated.

We have systematically studied the PVDF-based electrolytes with different salts and salt combinations, including lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and lithium bis(pentafluoroethanesulfonyl)imide (LiBETI). The optimized electrolyte delivers excellent performance for solid-state Li||LiFePO4 cells, achieving a specific capacity of over 150 mAh/g and lasting more than 50 cycles with over 99% capacity retention. Similar tests have also been applied to lithium nickel manganese cobalt oxides (NMC), and the preliminary results show promising cycling stability and capacity retention. In addition to electrochemical study, we employed a range of synchrotron-based X-ray techniques, including diffraction, pair distribution function analysis, and absorption spectroscopy, to investigate the interactions between the polymer and lithium salt in the polymer electrolytes. This knowledge will provide valuable information for designing new polymer electrolyte systems.

Acknowledgments: The work at Brookhaven National Laboratory was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Vehicle Technology Office of the U.S. Department of Energy through the Advanced Battery Materials Research (BMR) Program under contract DE-SC0012704. This research used beamline 23-ID-2 and 28-ID-2 of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.
An Electrochemically Polymerized Protective Layer for Magnesium Metal Anode
Authors: Wang Yang
Published: November 2022

Rechargeable magnesium (Mg) batteries are promising beyond Li-ion technologies due to their high volumetric capacity (3832 mAh cm−3) and high natural abundance. Nonetheless, Mg metal anode is incompatible with most conventional electrolytes which leads to the formation of an ionically passivating layer. Mg also suffers from growth of dendrites similar to Li, which causes failure of the cells. In this study, we electrochemically polymerized 1,3-dioxolane (DOL) to form a thin Mg2+-conducting elastomeric artificial solid electrolyte interphase (ASEI) layer by electrochemically pretreating Mg metal anodes. We found that this protective ASEI layer enables excellent cyclability of Mg-Mg symmetric cells at high current density (0.5 mA cm-2) over 400 hours at a stable low overpotential (0.50 V vs. Mg2+/Mg) without cell short-circuiting, while untreated pristine Mg symmetric cells quickly failed. The formation of this ASEI also significantly lowered the impedance of the cells, which proved its capability of conducting Mg2+ ions. Comprehensive surface chemistry analysis was done by X-ray photoelectron spectroscopy (XPS) which showed that an ASEI mainly consists of poly-DOL was formed, along with various Mg salts which are instrumental to the conductance of Mg2+ ions. More importantly, poly-DOL component in the elastomer was well preserved post-cycling, which contributed to the long-term cyclability and low voltage hysteresis of pretreated Mg-Mg cells, as compared to the pristine ones. Focused ion beam (FIB) – scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) mapping showed that a generally uniform layer was formed on the surface and this ASEI is roughly 200 µm thick and was able to suppress the growth of Mg dendrites after cycling for 400 hours at 0.03 mA cm-2 current density, as compared to the rampant sphere-shaped dendrites on the surface of pristine Mg anodes after cycling. This is the first ever report on the successful formation of poly-DOL ASEI on Mg metal anodes as a protective layer and by electrochemical polymerization method that effectively enhanced the electrochemical cycling performance of the Mg metal anodes.

Figure 1
In-Situ Gas Analysis of Sodium Nickel Manganese Oxide Cathodes Synthesized By Eutectic Method
Authors: Li Mengya , Jafta Charl , Geng Linxiao , Liu Jue , Bai Yaocai , Li Jianlin , Essehli Rachid , Belharouak Ilias
Published: November 2022

Sodium-ion batteries are one of the most promising next-generation energy storage systems because of their abundant and low-cost component materials. However, the lower energy density of sodium-ion batteries compared with lithium-ion batteries diminishes their practical value proposition. Among the many sodium-based cathodes, layered transition metal oxides with high sodium content can achieve energy densities comparable with the lithium-ion battery technology. For some layered transition metal oxide cathodes, when they are charged to above 4 V, a long plateau is often observed before they reach to fully charged state, which involves structural transformations that lead to irreversible reactions. Apart from structural transformations, lattice oxygen anion redox has also been proposed as a mechanism from both experimental results such as X-ray absorption spectroscopy, resonant inelastic X-ray scattering studies and simulation efforts. Reversible lattice oxygen anion redox is often accompanied by the generation of peroxo (O2
2-) or superoxo (O2-) related species. Irreversible lattice oxygen anion redox is often accompanied by the generation of molecular O2, along with transition metal ion migration, lattice distortion, and rapid capacity decay. In this work, in-situ gas analysis was performed to evaluate the gas generation in Na
x
NiyMn1-yO2 cathodes synthesized by eutectic method in sodium half-cell configuration. Operando x-ray diffraction and neutron diffraction were performed to assess the structural changes related to the high voltage plateau and transition metal ion migration in Na
x
NiyMn1-yO2 cathodes. The results unveil that in-plane honeycomb cationic ordering can help reduce the activity of irreversible oxygen anion redox which is critical for future design of layered transition metal oxide cathode that are prone to achieve high-energy for durable sodium-ion batteries.
More Reversible Anionic Redox Chemistry for Sodium Storage Triggered By Transition Metal Regulation
Authors: Cai Xinyin , Li Xun-Lu , Shadike Zulipiya , Zhou Yong-Ning
Published: November 2022

As one of the next generation battery system, sodium-ion batteries (SIBs) have been attached great interest for its abundant resources, low cost and good safety. Recently, high energy density cathode materials with anionic redox chemistry in SIBs have become the mainstream. The working potential of oxygen redox in layered transition metal oxide cathodes is about 4.2 V (vs. Na+/Na), which can not only elevate the battery potential but also harvest extra capacity. Thus, reasonably utilizing the oxygen redox can drastically increase the energy density of the batteries. However, the undesired phase transition and structural distortion resulted from oxygen redox usually lead to severe voltage hysteresis and capacity decay of the cathodes. Therefore, it is of great significance to investigate the relationship between the transition metal components and cycling stability of the cathodes, which provides valuable understanding for discovering novel cathodes with more reversible and higher capacity. To improve the structure stability and promote more anionic redox, we have been focusing on tuning the structure of P2-layered cathode materials with the different transition metal ligands such as Al/Ti/Zn-Mn. We have performed in-situ XRD and ex-situ XAS characterizations to investigate the charge compensation mechanism of the cathodes. The O K-edge XAS results indicated O e
g orbits variation at fully charged state and provided solid evidence of oxygen redox chemistry. Moreover, we combined EXAFS results and DFT calculations to construct the model of local structure distortion. These results provide further understanding of the oxygen redox chemistry mechanism and promote the development of high energy density SIBs.

Acknowledgement

The work was supported by the National Natural Science Foundation of China (No. 52071085).
A Multiphysics Understanding of Lithium Dendrite Growth Mechanism and Mitigation Strategy in All-Solid-State Batteries
Authors: Yuan Chunhao , Xu Jun
Published: November 2022

With the merits of high energy density from lithium metal electrode and safety performance improved by inorganic electrolyte, all-solid-state batteries (ASSBs) are considered promising candidates for future lithium-ion batteries. However, dendrite growth induced battery short-circuit (SC) failure are the obstacles on the commercialization road of ASSBs. To unravel the dendrite growth mechanism, the electrochemical-mechanical coupled multiphysics model is developed from the cell level, based on which the dendrite mitigation strategy is further proposed by adding heterogeneous blocks (HBs) into solid electrolytes (SEs). It’s discovered that the electrochemical overpotential induced mechanical stress is capable of driving the crack propagation, which provides space for the dendrite growth to penetrate through the solid electrolyte, eventually causing the SC. Larger charging rate and smaller electrolyte conductivity results in earlier SC. Higher fracture toughness increases the cracking energy to suppress dendrite growth, while Young’s modulus affects both the driving force and resisting force for crack propagation. By adopting HBs in SEs, the dendrite growth behavior can be modulated. We discover that the length ratio between HB and SE dominates the dendrite mitigation effect. Single HB in large ratio, and multiple HBs in medium ratio with specific arrangement, are capable of completely suppressing dendrite growth-induced SC risk. Furthermore, multilayer SE in more layers and smaller Young’s modulus shows promising dendrite mitigation effect by delaying SC time. Results give out a comprehensive understanding of dendrite growth mechanism as well as an effective strategy to mitigate dendrite, providing guidance on the design of more robust and practical ASSBs with dendrite-suppression electrolyte.
Development of a Solid-State Ta-Doped Lithium Lanthanum Zirconium Oxide Electrolyte for All-Solid-State Lithium Batteries (ASSLBs)
Authors: Panda Dillip K. , Creager Stephen , Bordia Rajendra Kumar
Published: November 2022

Large, high-power batteries are necessary for electric vehicles. The safety of batteries is also crucial, as damaged batteries should not be combustible. Moreover, in some cases batteries need to operate a modestly high temperatures in the range of 100 - 150 0C. All-solid-state lithium batteries (ASSLBs) can handle these requirements with ceramic electrolytes, lithium intercalation cathodes, and lithium metal anodes. Although ASSLBs using variations on this material set have been demonstrated, they tend to have low power, in part because of low ionic conductivity, as well as low rates of interfacial reaction between electrodes and electrolytes. Various strategies are being investigated to address the challenge of low power including operating at elevated temperatures, using doped electrolytes, increasing the contact area between the electrodes and the electrolyte, and through engineering of the interfaces between electrodes and electrolytes.

Using tape casting followed by sintering, we are producing thin (~20µm) and dense Ta-doped Lithium Lanthanum Zirconium Oxide (LLZTO) films, and also LLZTO pellets. The challenge of Li-loss during sintering has been addressed by using suitable sintering aids and sacrificial Li source. We have characterized LLZTO films and pellets using techniques such as XRD, SEM, and SEM EXA. The electrochemical properties of the LLZTO electrolyte including ionic conductivity have been measured. This is the first step in the creation of a full cell with engineered electrodes and interfaces. An analytical model has been developed to examine the effect of thickness of anode, cathode, and current collector on energy density.
The Interactions between Zn Anode and Electrolytes in Aqueous Zn-Ion Batteries
Authors: Huang Kevin
Published: November 2022

Aqueous based Zn-ion batteries have gained significant interest in recent years for their potential to be a safe, low-cost, and high-power energy storage device. The past research efforts have been mainly focused on cathodes and the associated interfaces with electrolytes. The understanding on the Zn-anode and its interface with the electrolyte has been relatively lacking. Here in this presentation, we will report a systematic fundamental study on the Zn-anode/electrolyte interface, including the effect of pH and concentration of the electrolyte on chemical reactions and electrode kinetics at the Zn-anode surface. We expect the insights revealed from this study will facilitate the understanding of the potential issues associated with the Zn-anode and help the commercial development of ZIBs.
Electrochemical Investigation of Kinetics and Mechanisms of Charge Transfer in Nonaqueous Zinc and Magnesium Electrolytes
Authors: Asselin Genevieve , Paden Olivia , Qiu Weiqi , Yang Zicheng , Sa Niya
Published: November 2022

Nonaqueous multivalent systems are competitive as future lithium-ion battery (LIB) replacements to address growing energy storage needs. High volumetric specific capacity, low cost, long lifetime, are some driving advantages of these systems. Their development has been slowed by a plethora of fundamental unknowns. Mechanisms of multivalent charge transfer are complicated and not well understood in detail. Strategic electrochemical investigation into fundamental redox mechanisms and kinetics of multi-charge transfer of Magnesium and Zinc nonaqueous electrolytes will be presented here. Influence of solvent system, concentration, anion identity, and solvent structure are investigated as each has an integral role.
High Energy Efficiency Rechargeable Li-Air Battery Enabled By Rational Design of Cell Components
Authors: Esmaeilirad Mohammadreza , Kondori Alireza , Asadi Mohammad
Published: November 2022

Electrical energy storage and conversion is vital to a clean, sustainable, and secure energy future. Among all electrochemical energy storage devices, lithium-air (Li-air) battery is known to offers as high as 5X greater energy density than lithium-ion batteries, representing its promise for electrical vehicles and stationery (micro-grids) applications. However, their practical realization is hindered by their poor rechargeability and rate capability, mostly due to unsuitable design of cell components, i.e., anode, cathode, and the liquid electrolyte.

Here, we are presenting an aprotic Li-air battery cell, enabled by rational design of cell components, that can be cycled over 2400 hours at a capacity of 500 mAh/g (specific energy of about 400 Wh/kg) in an air-like atmosphere consisting of water and other air components. The developed Li-air battery cell leverages a highly active cathode catalyst, a hybrid aprotic electrolyte with two specific redox mediators, and an effective anode protection layer. Our physicochemical and electrochemical characterization of the developed Li-air battery cell indicate that lithium peroxide (Li2O2) is formed as the only discharge product formed via the solution-based mechanism and is reversibly decomposed during the charge processes. Moreover, different electrochemical experiments were performed to find out the rate capability and the deep discharge performance of the developed Li-air battery cell. We found that the designed cell components work well in synergy to deliver the lowest overpotentials reported to date for the discharge and charge (80 and 270 mV, respectively) at the first cycle, resulting in a high energy efficiency of about 90% at the first cycle. This battery design scheme offers significant promise in the advancement of sustainable energy storage systems.
(Invited) FC-Platform and Gen2 Mirai Analysis
Authors: Amemiya Kazuki , Shinohara Kazuhiko , Kawase Motoaki , Imai Hideto , Sodeyama Keitaro
Published: November 2022

FC-Platform, specialized in PEFC's analysis and evaluation, has been launched as a NEDO's funded project. PF-Platform consists of 5 groups of the electrochemical evaluation, simulation, materials analysis, materials informatics and management, involves 21 institutions. An number of various materials research themes are also running in the NEDO's project. FC-Platform provides better direction of improving for these materials research by analysis and evaluation. Moreover, visualizing and predicting phenomena in the PEFCs are important for realizing high performance and durability at a material level. Therefore, we are focusing on advanced visualization techniques and multi-scale stack modeling development. We conducted analysis and evaluation of Gen2 MIRAI's MEAs and its materials employing developed analytics and modeling in this framework.

This work was supported by a NEDO FC-Platform project commissioned by the New Energy and Industrial Technology Development Organization (NEDO). Toyota Motor Corporation supported for providing MIRAI's MEAs and materials.