bluuebunny/crossref_metadata_2025 huggingface dataset:
Boosting the Performance of Solid-State Lithium Batteries Via Dual Interface Design of Ga-Doped Li7La3Zr2O12/Polymer Solid Electrolyte
Authors: Panda Ananya , Rath Purna Chandra , Chang Jeng-Kuei
Published: November 2022

Solid-state lithium-metal batteries (SSLMBs) with a Li7La3Zr2O12-based composite solid electrolyte (CSE) show great potential for overcoming the safety and specific energy concerns of conventional liquid-electrolyte Li-ion batteries. Nevertheless, achieving a satisfactory connection between a solid electrolyte and the cathode and anode materials is a major challenge. Three strategies have been adopted in this work to improve the performance of SSLMBs. First, the Ga concentration in Ga-doped Li7La3Zr2O12 (LGLZO) was adjusted. We first revealed the strong impact of the Ga stoichiometry on the battery performance. Second, a spin-coating method was used to fabricate an LGLZO CSE layer directly on top of a LiFePO4 (LFP) cathode. This practice can improve the cathode/CSE interfacial contact and establish a Li+ conducting network within the cathode. Third, the ionic liquid (IL) connection interlayer was applied between the Li metal electrode and the CSE to facilitate the Li+ transport across the interface, homogenize the Li+ flux, and form a robust SEI for suppressing side reactions. The IL also functioned as a plasticizer to enhance the segmental motion of the polymer chains, increasing the Li+ conductivity. We found that the TFSI− IL anion is superior to FSI− for the rate capability and cycling stability of the cell. We believe that the proposed dual interface design can be utilized to cost-effectively address the electrode//electrolyte interface problems, which are crucial for the practical application of SSLMBs.
Preparation of Li-Si-P-S-O-N Glasses: The Impact of Lipon Incorporation on Ionic Conductivity
Authors: Torres III Victor Manuel , Martin Steve , Philipp Presley
Published: November 2022

Lithium glassy solid electrolytes (GSEs) are an alternative to liquid electrolytes in the development of solid-state batteries. Mixed oxy-sulfide nitride GSEs incorporate the useful properties of sulfide glasses, which show high ionic conductivity, of oxide glasses which display excellent chemical stability, and of nitride glasses which exhibit good electrochemical stability. In our investigation of these new GSEs, the following compositional series was explored Li2S + SiS2 + [(1-x)Li0.67PO2.83 + xLiPON]. Differential scanning calorimetry (DSC) was employed to determine the crystallization and glass temperatures of these GSEs. In addition, electrochemical impedance spectroscopy (EIS) was used to determine the temperature-dependent ionic conductivity of theses GSEs. X-ray Photoelectron Spectroscopy (XPS) was conducted on the glasses to further understand the chemical bonding environment of nitrogen. It was found that x = 0.2 displayed the highest ionic conductivity suggesting that nitrogen incorporation can be used to optimize mixed oxy-sulfide glasses.

Support of this research by NSF Grant NSF-DMR-1936913 is acknowledged.
Overlimiting Currents and Sand’s Time Behaviors in Solid Polymer Electrolytes
Authors: Lee Youngju , Bai Peng
Published: November 2022

Dendrite growth in solid polymer electrolytes has been frequently analyzed since it was the critical issue that limited its applications. For the liquid electrolyte systems, the dilute solution theory and the classic Nernst-Planck equation have been proven to be useful tools for analysis of ion transport dynamics and especially the dendrite initiation at Sand’s time. However, characterization of the Sand’s time in solid polymer electrolyte systems is challenging and also seldomly performed. From the experimental perspective, operando observations have been done, but the true local current density was different from the geometrical average current density since there was always heterogeneous current distribution for millimeter-scale electrolytes. From the theoretical perspective, the dendrite initiation time followed the trend predicted by Sand’s equation, but discrepancies were found such as dendrites observed at under-limiting currents or the order-of-magnitude extended Sand’s time compared to theoretical predictions. Here, we use transparent microcapillary cells for solid polymer electrolyte systems to overcome these challenges. These specialized cells allow direct operando optical observations, while the micron-scale cross-sectional area minimizes the discrepancy between true local and averaged geometrical current densities. Comparison between operando image and voltage response during constant current polarization shows that, unlike liquid electrolyte cases, the dendrite initiation for solid polymer electrolytes doesn’t always trigger a voltage spike. We also derived transport parameters from the measured Sand’s time, limiting current density, and conductivity and the cross-validated transport parameters were used to calculate theoretical Sand’s time that can be compared with the experimental values. Using the analytical solution from the Nernst-Planck equation and numerical calculations using Newman’s concentrated solution model and COMSOL Multiphysics, the predicted Sand’s time for the dilute and concentrated solution theory both matched closely with our experimental values. This work demonstrates that while the polarization process and the onset of lithium dendritic growths in solid polymer electrolytes can be still accurately predicted by the dilute solution theory, it may not always result in voltage responses similar to that of the liquid electrolyte cases. It’s also suggested that ensuring the homogenous distribution of lithium flux and avoiding the localized overlimiting current density is the key to realizing the dendrite-free polymer electrolytes.
Electrochemical Characterization of a Drawn Thin-Film Mixed Oxy-Sulfide Glassy Electrolyte Material for Solid-State Battery Applications
Authors: Wheaton Jacob , Martin Steve
Published: November 2022

Solid-state batteries are a promising avenue for next-generation lithium-ion batteries due to their enabling of the lithium metal anode, while simultaneously removing the flammable organic electrolyte. Glassy materials are particularly interesting as solid-state electrolytes due to their intrinsic lack of grain boundaries, their low temperature forming capabilities, and their highly tunable chemistries. Much work has been done to study the electrochemical properties of glasses in the Li2S – SiS2 – LixMOy phase space, and several compositions have shown high ionic conductivities (~ 10-3 S/cm), large electrochemical stability windows (0-5 V vs. Li/Li+), and good glass forming ability. These glasses, however, have not been well studied at thicknesses that are viable for commercialization of solid electrolytes (< 100 μm). Utilizing a glass working method known as the redraw process, a rectangular preform of glass can be reheated and drawn from ~ 5 mm in thickness to thin films of less than 100 μm. The electrochemical behavior of thin-film glasses in the Li2S – SiS2 – LiPO3 phase space created through the glass redraw process are studied utilizing electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic symmetric cell cycling. These results show that thin-film glassy solid electrolytes made through the glass redraw method are a viable new research direction for generation of highly conducting thin-film solid-state electrolytes.
Polyhydroxy Urethanes and Carbonates Bearing Bio-Based Solid Electrolyte for Solid-State Lithium Batteries
Authors: Raj Ashish , Grignard Bruno , Detrembleur Christophe , Gohy Jean-François
Published: November 2022

With higher energy density, flexibility, safe operation at both room temperature as well as high temperature, solid-state batteries technology has been strongly looked upon as superior diversion from conventional liquid electrolytes-based lithium batteries. Among various other class of polymers, there is strong need to focus on sustainable and yet better alternatives other than most researched polyethylene oxide (PEO). Poly(hydroxyurethanes) (PHU) owing to their high degree of structural tunability can be interesting candidates for Solid polymer electrolyte (SPE). Here, we synthesized bio-based PHU networks by facile ring-opening polymerization of carbonated soybean oil (CSBO) without catalyst. The existence of polyether and polyester provides the PHU network with soft segments while urethane linkage with hard segments. The lower Tg with higher thermal stability widespread its application at elevated temperature without melting and significant degradation. PHU shows remarkable adhesive properties to the surface of metal speculating better interfacial contact and stability. The electrochemical investigations exhibited decent ionic conductivity (> 10-4 at 60o C), electrochemical stability window (ESW > 4.5 V vs. Li/Li+) and transport properties allowing it to be explored for high voltage cathodes. Lithium ferrophosphate (LiFePO4) cells with PHU also demonstrated promising charge-discharge (> 100 mAhg-1 at 60o C) with the li-metal anode. The attempt to develop bio-based batteries materials are much required added step toward green and clean energy for a sustainable future.
Benchmarking the Electrochemical Degradation Behavior of Aluminum Foil Anodes for Lithium-Ion Batteries
Authors: McDowell Matthew , Thenuwara Akila , Yao Wendy , Sandoval Stephanie Elizabeth , McDowell Matthew
Published: November 2022

Aluminum is an attractive candidate for replacing graphite anodes in lithium-ion batteries because it has high specific capacity (990 mAh g-1), and directly using aluminum foil as the anode structure eliminates the need for slurry-coating processes. However, achieving highly reversible lithiation and delithiation of aluminum is challenging due to volume changes during transformation, sluggish lithium-ion transport through the surface oxide layer, and poor initial Coulombic efficiency which all lead to degradation during cycling. Previous studies have focused on understanding the fundamental electrochemical reaction and material transformation behaviors of aluminum, yet there has not been a focus on how different aluminum alloy compositions behave and degrade under electrochemical cycling conditions. In this work, we carry out comprehensive electrochemical testing to benchmark the performance of three different aluminum alloy foils under different cycling conditions. We found that for foils of constant thickness, all foil compositions exhibit a power-law dependence of cycle life on the areal capacity lithiated per cycle, revealing that degradation is significantly accelerated when high areal capacities are used each cycle. Furthermore, the composition of the aluminum alloy was found to strongly affect the Coulombic efficiency over the first 10 cycles, with higher purity foils exhibiting higher Coulombic efficiency. Finally, ex situ scanning electron microscopy and operando optical microscopy revealed different reaction mechanisms and mechanical degradation behavior amongst the different alloys. Based on understanding these various parameters, we showed how full cells with aluminum anodes can be cycled for hundreds of cycles at relatively low areal capacities. The improved understanding of the behavior of aluminum foil anodes herein paves the way for future work intended to engineer aluminum-based foils with enhanced stability.
Ab Initio Insights into the Solid Electrolyte Interphase Formation in Lithium Metal Batteries with Carbonate Electrolytes
Authors: Kuai Dacheng , Balbuena Perla B.
Published: November 2022

As the research endeavors push the performance of widely used Li-ion battery to its theoretical limit, there are strong urges to develop next-generation energy storage devices. Li metal is a promising candidate battery anode material which can bring the energy density to a higher level. There are safety and cycling efficiency issues associated with the Li-metal battery (LMB), and the metal dendrite nucleation and lithium whisker formation are largely responsible for them. The solid electrolyte interphase (SEI) generated from the reactions between lithium metal and battery electrolyte components can regulate the lithium-ion diffusion and deposition which protects anode materials from undesired consumptions. According to the experimental evidence, the SEI from carbonate electrolytes may contain inorganic components including Li2O, Li2CO3, LiF, as well as organic structures such as polymers and oligomers with carbonate and carbonyl structures. However, the exact composition and ionic diffusion properties of SEI are challenging to be directly characterized via experimental techniques.

In this work, we initiated the elucidation of the SEI composition by investigating plausible reaction pathways. The inorganic structures are mainly resulted from the degradation of electrolyte solvent and salt species upon contact with the anode material. Ab initio molecular dynamics (AIMD) simulation was implemented to track the interfacial reduction of ethylene carbonate (EC), vinylene carbonate (VC) and lithium hexafluorophosphate (LiPF6). Bader charge analysis demonstrated that the LiPF6 reduction requires consecutive uptake of outside electrons, no matter such reaction happens right on the metallic surface or in electrolyte phase. The final product of the LiPF6 degradation was determined to be Li3P, and the reaction thermochemistry was computed based on density functional theory (DFT). The experimentally measured battery electrochemical performance enhancement of the VC additive has been reported while the chemical mechanism behind such phenomenon was less discussed. We modeled the degradation and polymerization reactions of EC and VC molecules in the LMB environment. VC has significantly smaller energy barrier than EC to generate the lithium-carbonyl complexes and the oligomer/polymer species which takes longer time scale to form. In addition, the solvated lithium cation was found to have significant contribution to the polymerization reaction thermodynamics. The most kinetically favored pathways and products for EC and VC polymerization were identified via DFT calculations. Multiscale simulation based on the computed thermodynamic information was able to provide a glimpse of the microscopic morphology inside the SEI.
Electrolytes and Interfaces Driven Thermal Stability of Sodium-Ion Batteries
Authors: Sarkar Susmita , Mukherjee Partha P.
Published: November 2022

Recognizing the mandates in sustainability and material abundance, sodium-ion batteries hold great potential in being alternate chemistry for applications such as grid storage systems. Along with other performance matrices, the safety problem known as “thermal runaway” must be understood and overcome for the practical realization of sodium-ion batteries in countless applications. While the physiochemical properties of the model electrode materials play a major role in determining overall thermal stability, electrolyte-derived unstable solid electrolyte interphases (SEI) can also trigger early thermal instability. Since the sodium-ion battery has a highly soluble SEI layer, especially in carbonate electrolytes, it is essential to understand the thermal instability signatures of electrode-electrolyte interactions. So far, the interfacial driven thermal stability of sodium-ion battery electrodes remains largely unexplored. Herein, we aim to investigate the intrinsically stochastic and heterogeneous nature of the SEI layer, illustrating the role of carbonate and glyme solvents in determining the overall thermal stability of the cell. The fundamentals of the thermal failure issues explored in this work can pave the way toward building a safer sodium-ion battery.
Enabling Ambient Sodium Sulfur Batteries
Authors: Carter Rachel Elizabeth , Lefler Matthew , Sarkar Susmita , Dunkelberger Adam , Sassin Megan B. , Pyles Cynthia , Love Corey T.
Published: November 2022

Sodium and Sulfur are attractive energy storage materials because of their reactivity with each other and global abundance. Therefore, the Na-S battery is one of the oldest conceptualized batteries (Ford 1960s). However, the complex, multistep electrochemical reaction between the two has prevented commercial realization. We couple novel ultrafast spectroscopy with optical microscopy to bridge length and time scales of the reaction, to obtain the fundamental information necessary to facilitate a functioning battery (separator, electrolyte, geometry, etc.). With in-situ optical microscopy, we observe polysulfide anions ranging from S8^2- to S3^.- via color changes in the electrolyte during electrochemcial cycling on the order of hours. The observed, soluble species contribute to the reaction complexity and are most commonly blamed for low cell capacity or poor capacity retention. To better understand their interaction with the electrolyte solvent, novel pump/probe, ultrafast lasing is used to observe transient signals indicative of chemical recombination. This allows comparison of the strength of polysulfide interaction with solvent molecules at specific cell voltages and in various electrolyte cocktails. Similar analysis is also used in a symmetric sodium system to isolate plating and stripping phenomenon from the sulfur reaction.
Multiscale Modeling of Solid Electrolyte Interphase Growth in Lithium-Ion Batteries
Authors: Verma Ankit , Weddle Peter J , Schulze Maxwell , Abraham Daniel P. , DeCaluwe Steven C. , Colclasure Andrew M.
Published: November 2022

Calendar and cycle life of lithium-ion batteries (LIBs) are predominantly dictated by the passivating nature of the solid electrolyte interphase (SEI) film growth on battery anodes. Graphitic anodes exhibit stable SEI growth which enables ubiquitous commercialization of LIBs. In contrast, silicon anodes exhibit poorly passivating SEI characteristics including rapid thickness and composition changes during cycling (“breathing”) and sensitivity to electrolyte composition and surface functionalization. In this work, we develop a chemically complex continuum-level multicomponent, multiphase coupled thermodynamics-reaction-transport SEI model to unravel the mechanisms of SEI growth in LIB anodes. Atomistic calculations in conjunction with experimental datasets are utilized to ascertain the dominant decomposition pathways towards predominant SEI components like Li2EDC, Li2O, Li2CO3, LiMC, LiF etc. and inform the continuum model predictions. Furthermore, experimental voltage-hold measurements are utilized to validate the SEI model parasitic currents/composition evolution profiles enabling prediction of voltage regimes for stable SEI growth with favorable SEI composition. The development of such chemically complex SEI models will aid predictive electrolyte screening for the growth of stable and passivating SEI layers on next generation anodes like silicon.

Figure 1(a) shows a schematic of the detailed SEI model incorporating species and charge transport through the pore and solid phases of the SEI for LEDC formation. Figure (b) showcases experimental leakage currents during V-hold at 100 mV and 250 mV for Li-Si half cells and the detailed SEI model fits. Figure (c) shows the SEI composition profiles predicted by the model and the formation of inner inorganic (Li2CO3, Li2O) - outer organic (LEDC) bilayer SEI. Interestingly, inorganic LiF from FEC decomposition is predicted to form throughout the SEI.

Figure 1
Microstructure-Coupled Kinetic-Transport Interactions in the Solid-State Cathode
Authors: Naik Kaustubh Girish , Vishnugopi Bairav Sabarish , Mukherjee Partha P.
Published: November 2022

Solid-state batteries (SSBs) are a promising choice for next-generation energy storage systems due to their high intrinsic energy and power densities, while simultaneously enhancing safety. The electrochemical performance of SSBs is a strong function of the physicochemical interactions occurring inside composite cathode microstructure. The composition and spatial arrangement of constituent phases (e.g., active material, binder, conductive diluent, solid electrolyte) dictate the ionic/electronic percolation pathways and internal resistive signatures. Moreover, the underlying heterogeneity in cathode microstructure can result in non-uniform kinetic and transport processes leading to current focusing and thermal hot spots. Thus, understanding the influence of cathode microstructural heterogeneity on spatiotemporal dynamics of SSBs becomes important. In this work, the mesoscale underpinnings of microstructural heterogeneity in composite cathode and its mechanistic implications on the electrochemical response of SSBs will be examined.
Understanding the Parameters Influencing the Impedance Response of Sulfur-Carbon Composite Cathode in Lithium-Sulfur Batteries
Authors: Nojabaee Maryam , Gerle Martina , Häcker Joachim , Wagner Norbert , Friedrich K. Andreas
Published: November 2022

Lithium-sulfur (Li-S) batteries, which in recent years have been aimed at a high gravimetric energy density of 500-600 Wh kg-1, indicate particular potential in aerospace applications such as aircraft, satellites and drones.1,2 In light of this, the German Aerospace Center (DLR) has been pursuing a strategy of developing and researching metal-sulfur batteries for a decade. Herewith, we present the results of a fundamental study on the investigation of structural and compositional parameters affecting the electrochemical performance of sulfur-carbon composite cathode.

Highly porous carbon materials are widely employed in composite cathodes in Li-S batteries to compensate for the non-conductive property of the sulfur element. Indeed, this would have significant effects not only on the conductivity of the cathode, but also on the diffusion and charge transfer parameters. Herewith, we have systematically studied porous carbon-based electrodes employing electrochemical impedance spectroscopy. Using a suitable transmission-line model peculiar to the porous electrodes, the resistance of bulk and pore electrolyte, inter-particles, and charge transfer is defined and quantified. The dependence of the identified processes at the open circuit voltage on the fraction of the active material, the porosity of utilized carbon and thickness of the electrode is investigated elaborately. It is indicated that the electrolyte resistance in the pore increases on increasing the content of active material, electrode thickness and on reducing the pore size distribution of the C component.

Additionally, an innovative symmetrical three-electrode cell configuration with an integrated Li-ring serving as counter electrode is implemented, enabling the investigation of the cathode impedance at different depths of discharge to shed light on the kinetics of the charge transfer depending on the infiltration method. To this end, various porous carbon materials such as Ketjenblack® (mesoporous) and carbon aerogel (microporous) in combination with different sulfur infiltration techniques including gas, melt and mechanical mixing have been employed as model systems3. The thermodynamic and kinetics of charge transfer mechanisms as a function of infiltration method as well as the variation of the charge transfer resistances upon discharge/charge are discussed in details4.

A. Fotouhi, D. J. Auger, L. O’Neill, T. Cleaver and S. Walus, Energies, 2017, 10, 1937.

Sripad S., Viswanathan V. (2017), ACS. Energy. Lett.2, 1669-1673

M. Nojabaee, B. Sievert, M. Schwan, J. Schettler, F. Warth, N. Wagner, B. Milow, K. Andreas Friedrich, J. Mater. Chem. A, 2021,9, 6508-6519.

Martina Gerle, Norbert Wagner, Joachim Häcker, Maryam Nojabaee, Andreas Friedrich J. Electrochem. Soc., 2022, 169, 030505.
Development of Argyrodite-Based Sulfide Electrolytes for Next-Generation Solid-State Li Batteries
Authors: Yang Guang , Self Ethan , Brahmbhatt Teerth , Mills Anna , Tsai Wan-Yu , Hallinan Daniel , Chen Xi , Delnick Frank , Nanda Jagjit
Published: November 2022

Advances in solid electrolytes (SEs) with superionic conductivity and stabilized electrode-electrolyte interfaces are key enablers for all-solid-state batteries (SSBs) to meet the energy density and cost targets for next-generation batteries for electric vehicles. Argyrodite sulfide-based electrolytes with the nominal composition Li6PS5X; where X= Cl and/or Br, I provide several key advantages over other types of SE counterparts, including (i) exceptionally high ionic conductivities up to 10-2 S/cm at room temperature (comparable to nonaqueous liquid electrolytes), (ii) availability of low temperature and inexpensive synthesis routes to produce glass, glass-ceramic, and crystalline structures, and (iii) soft mechanical properties facilitating material processing and solid-state battery (SSB) fabrication.

Several key challenges exist for the practical use of the argyrodite sulfide-based electrolyte in an SSB: (i) scale-up synthesis to produce phase-pure materials, (ii) rationale processing method development to produce free-standing thin film SSEs, and (iii) identifying buried interfacial side-reaction products at the electrode/electrolyte interfaces using advanced characterization tools.

In this talk, we will present our recent achievements focusing on tackling each of these challenges, including (i) solution-based synthesis of Li6PS5X; (ii) optimizing binder, slurry composition, and processing method to make Li6PS5X thin film (<50 µm) SSEs, and (iii) combining in-situ Raman spectroscopy and microscopy with complementary electrochemical impedance spectroscopy (EIS) to explore electrode/ Li6PS5X interfacial stability.

Acknowledgment

This research conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) is sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) in the Vehicle Technologies Office (VTO) through the Advanced Battery Materials Research (BMR) Program.
3D Asymmetric Bilayer Garnet Hybridized High-Energy-Density Lithium-Sulfur Batteries
Authors: Shi Changmin , Nolan Adelaide , Takeuchi Saya , Fu Zhezhen , Dura Joseph , Wachsman Eric
Published: November 2022

Li7La3Zr2O12 (LLZO) has high ionic conductivity and stability against a Li metal anode making it a promising solid electrolyte for Lithium-Sulfur batteries. However, typically reported discharge capacity does not achieve theoretical. Therefore, we addressed this by forming a stable sulfur cathode/LLZO interface through a poly(ethylene oxide) (PEO)-based interlayer, with a small amount of catholyte used to maintain physical contact and ionic conduction between sulfur cathode and the PEO-based interlayer. With a thin bilayer LLZO and the stabilized sulfur cathode/LLZO interface, the hybridized Li-S batteries achieved an initial discharge capacity of 1307 mAh/g at a current density of 0.2 mA/cm2 (0.03C) at room temperature (22°C) without any indication of a polysulfide shuttle. With specific optimization, an energy density of 1308 Wh/L and 485 Wh/kg is achievable.

The mechanisms regarding the cell stabilization are presented: 1). X-ray Diffraction and X-ray Photoelectron Spectroscopy indicate that the PEO-based interlayer which physically separates the sulfur cathode and LLZO, is both chemically and electrochemically stable with LLZO. 2). Due the physical separation between liquid electrolyte and LLZO through the PEO-based film, the proton/Li+ exchange with the moisture in liquid electrolytes was avoided. 3). PEO-based interlayer can adapt to the stress/strain associated with sulfur volume expansion during lithiation to protect LLZO from failure.
Assessing Mediated Redox Flow Battery Reaction Progression
Authors: Koenig Gary , Gupta Devanshi , Wang Jing , Zhang Yuxuan
Published: November 2022

One potential next generation battery system is mediated redox flow batteries (RFBs). With mediated RFBs, soluble electroactive species (redox shuttles) deliver power via electrochemical reactions in a flow-through stack reactor much like a conventional RFB. However, the redox shuttles then undergo chemical redox in a coupled chemical reactor system with solid electroactive materials. The use of solid electroactive material for chemical energy storage results in substantial increases in volumetric energy density for the system.

Mediated RFBs with different configurations for the chemical redox reactor have previously been reported. In this work, a packed bed reactor system will be described, where the impact of varying different experimental parameters on the chemical redox progression will be highlighted. Generally, the progression of the chemical redox can be tracked in the lab by taking advantage of electrochemical analytical techniques. However, additional assessment of the reaction progression using neutron imaging will also be discussed. Neutron imaging offered a unique opportunity to access the spatial progression of the chemical redox in the packed bed reactor. The combination of techniques for assessing the chemical redox progression provides insights into the limiting processes in the reactor systems.
(Invited) Accelerating Material Design for Aqueous Organic Redox Flow Batteries
Authors: Wang Wei
Published: November 2022

Aqueous soluble organic (ASO) redox-active materials have recently shown great promise as alternatives to transition metal ions to be employed as energy-bearing active materials in redox flow batteries for large-scale energy storage because of their structural tunability, cost-effectiveness, availability, and safety features. Development so far however has been limited to a small palette of organics that are aqueous soluble. How to quickly identify and design organic molecules for the targeted properties became a critical challenge in accelerating the aqueous organic flow battery development.

In this presentation, a data-driven material design process is discussed. This process incorporates database building, machine learning modeling for properties prediction, and the subsequent material synthesis and testing. Examples including Fluorenone and Phenizane derivative development for the flow battery application will be discussed.
(Invited) An Electrolyte Odyssey with Bob Savinell
Authors: Zawodzinski Thomas A.
Published: November 2022

Over approximately 30 years, I have enjoyed interweaving my career with interactions with Bob Savinell. After some initial remarks on that ‘odyssey’ (or is it oddity?), I will discuss recent research in two pathways in which we overlapped: (i) an indirect one devoted to finding fuel cell membranes and systems that operate at temperatures above 100oC; and (ii) our direct interactions on the BEES EFRC.

Of course, the Savinell group proposed an elegant solution to that with the PBI-PA based fuel cell membrane and that has substantial system advantages for certain modes of operation. However, more mainstream PEM fuel cell membranes operating at T >100oC and with relatively little water continue to be sought. These are of considerable import because of the possibility that a car or truck will experience temperature excursions in that range. I will summarize the current state of the art of that field and discuss work in our lab that attempts to provide some solutions. I will also discuss our group’s work with a variant, the Solid Acid Fuel Cell, showing some progress achieved toward dramatic decreases in catalyst loading for a fuel cell that operates at roughly 250oC;.

In BEES, our group has worked on several issues (see other presentations in this symposium and meeting) but much of the focus has been on microemulsions as electrolytes, particularly in the context of redox flow batteries. I will present a brief overview of that work as the most direct and recent example of our collaborations.
(Invited) HT-PEMFC Based on Acid Doped Polybenzimidazoles of the Past Quarter Century
Authors: Hjuler Hans , Li Qingfeng , Aili David , Jensen Jens Oluf Oluf , Cleemann Lars N. , Azizi Kobra , Seselj Nedjeljko
Published: November 2022

High-temperature proton exchange membrane (HT-PEM) fuel cells based on phosphoric acid-doped polybenzimidazole (PBI) membranes were invented in 1994 by professor Bob Savinell and his coworkers at Case Western Reserve University [1]. The membrane electrolyte is a unique material that is capable of practical proton conductivity at temperatures of up to 200oC under anhydrous conditions. This ground-breaking invention has led to the start of a frontier research area for fuel cells and related technologies, as indicated by an annual publication of ca. 200 items and citation of 10,000 times in the last decade.

Based on this type of membrane materials, the HT-PEM technology has developed, with operating features including little humidification, high CO tolerance, easy thermal management and thermal integration with methanol reformer.[2] Significant efforts from international industries are currently made towards commercialization and products are now on the market. Research institutions and industries in Denmark have been active and leading in the research and development of the area. Further, the PBI membrane has also emerged as a promising membrane material for redox flow batteries (RFB).

This presentation is devoted to a brief summary of the fundamental understanding and technological deployment of this technology [3], as a remark of the extraordinary contributions of Professor Savinell to the electrochemistry and electrochemical engineering research.

References

[1] J.S. Wainright JS, J.T. Wang, D. Weng D, R.F. Savinell, M. Litt. Acid-doped polybenzimidazoles—a new polymer electrolyte. J Electrochem Soc 1995;142:L121–3.

[2] Q.F. Li, D. Aili, H. A. Hjuler, J.O. Jensen, High Temperature Polymer Electrolyte Membrane Fuel Cells - Approaches, Status and Perspective, ISBN 978-3-319-17081-7; Springer International Publishing, New York, 2015.

[3] D. Aili, D. Henkensmeier, S. Martin, B. Singh, Y. Hu, J. O. Jensen, L. N. Cleemann, Q.F. Li, Polybenzimidazole-Based High-Temperature Polymer Electrolyte Membrane Fuel Cells: New Insights and Recent Progress, Electrochemical Energy Reviews (2020) 3:793–845
(Digital Presentation) Fundamentals of Deep Eutectic Solvents As Electrolytes for Lithium-Ion Batteries
Authors: Elgammal Ramez A. , Fraenza Carla Cecilia , Greenbaum Steven , Zawodzinski Thomas A.
Published: November 2022

Deep eutectic solvents (DESs) have emerged as an alternative to both common organic solvents and ionic liquids (ILs). DESs share physicochemical properties with ILs such as low vapor pressure, high thermal stability, high viscosity while offering advantages such as low toxicity, lower cost, and ease of preparation. Moreover, DESs are attractive candidates for electrochemical applications due to their large voltage windows and solubility properties. DESs as a solvent class share a general composition of a hydrogen bond donor (HBD), typically a polyol, amide, or acid, and a hydrogen box acceptor (HBA), usually a quaternary ammonium or phosphonium salt. At a specific molar composition of a HBD and HBD, the DES forms a eutectic mixture resulting in a large melting point depression due to extensive hydrogen bonding between the components.

Despite being widely studied, the microscopic structures of DESs have remained largely uncharacterized. Herein, we present a multitechnique NMR study of two DESs: glyceline (glycerol + choline chloride) and ethaline (ethylene glycol + choline chloride). Fast-field cycling 1H relaxometry, pulsed field gradient diffusion, nuclear Overhauser effect spectroscopy (NOESY), 13C NMR relaxation, and pressure-dependent NMR experiments are deployed to sample a range of frequencies and modes of motion of the polyol and choline components of the DES. Generally, translational and rotational diffusion of polyols are more rapid than those of choline while short-range rotational motions observed from 13C relaxation indicate slow local motion of glycerol at low choline chloride (ChCl) content. We show how the additional hydroxyl group present in glycerol contributes to not only higher viscosities, but a larger perturbation of the hydrogen bonding network by the addition of ChCl.

Additionally, we have investigated the solubility properties of several lithium salts (LiTFSI, LiFSI, LiPF6, LiBF4, and LiOAc) in these DESs and utilized the same suite of NMR techniques to understand how they act as solvents. We observe that due to anion effects, the heterogeneities present in DES result in differential solvation for some species where there is a distinction of lithium salts co-existing in these holes as well as the bulk. The large changes in the structural organization of DESs that result from the presence of lithium salts will serve as a guide to the design of a new class of electrolytes for lithium-ion batteries.
Synergistic Effect of Interfacial Engineered Fe Doped Nis for Seawater Splitting
Authors: Lee Hoyoung , Chung Jiyong , Yu Taekyung , Lee Seung Woo
Published: November 2022

Seawater electrolysis for hydrogen (H2) production has been considered one of the most promising yet challenging strategies to overcome the energy and environmental crises. The ocean can provide infinite hydrogen, which provides 96.5% of the planet’s water reserve, but still there are numerous obstacles that limit the practical application of its electrocatalytic reactions. Despite enormous efforts, poor stability caused by contamination from toxic and corrosive chlorine species, low energy efficiency due to high overpotential and sluggish kinetics of the oxygen evolution reaction (OER) of four electron-proton couple reactions, and the absence of large-scale manufacturing technics for earth-abundant elements based electrocatalysts still unresolved. Recently, many tactics have been proposed to improve energy efficiency, and among them, foreign elements doping and interfacial engineering of electrocatalysts are attracting a lot of attention. In this study, interfacial engineered Fe doped NiS electrocatalyst is designed and fabricated by ball-milling method, which is not only favorable to large-scale fabrication for electrocatalysts, but also improves the electrocatalytic performance by controlling the grain boundary and Fe doping concentration. Synthesized interfacial engineered Fe doped NiS electrocatalyst exhibit high OER performance of 300 mV at a current density of 1000 mA cm-2. It also shows the high durability for the OER process in seawater. It is expected that this interfacial engineering technic by ball-milling method contributes to sustainable H2 production industry by designing and mass-producing superior electrocatalytic performance of high durability and low overpotential for seawater splitting.
(Invited) Interfacial Engineering of Battery Materials Using Atomic Layer Deposition
Authors: Dasgupta Neil P.
Published: November 2022

In batteries, like all electrochemical systems, interfacial phenomena play a critical role in thermodynamic stability, charge transfer kinetics, and ionic transport phenomena. For example, in Li-ion batteries, the solid-electrolyte interphase (SEI) layer enables stabilization of liquid electrolytes against continual electrolyte decomposition. In solid-state batteries, the dynamic morphological evolution of the interface results in unique electro-chemo-mechanical properties, which dictate performance, degradation, and ultimate failure.

As a result of these coupled phenomena, there is a continued need to improve both our fundamental understanding of interfacial dynamics, as well as new strategies to engineer rationally-controlled interfaces. Among the various interfacial engineering methodologies, atomic layer deposition (ALD) has risen in interest in recent years, owing to its unparalleled ability to impart atomically-precise control of surface composition and structure, while maintaining conformal coating of ultra-high aspect ratio structures.

In this talk, I will describe recent progress in applying ALD for battery applications. In the field of Li-ion batteries, I will show how deposition of a single-ion conducting solid electrolyte on the surface of graphite anodes can eliminate electrolyte decomposition and SEI formation, resulting in a four-fold decrease in interfacial resistance [1]. This results in lower cell polarization during fast charging, eliminating deleterious Li plating on the anode. In the field of Li metal batteries, I will also show how ALD coatings can influence nucleation and growth, resulting in improved Coulombic efficiency [2]. Finally, I will describe efforts towards incorporation of ALD films into solid-state batteries, where mechanical properties play a critical role [3-4].

[1] E. Kazyak, K.-H. Chen, Y. Chen, T. H. Cho, N. P. Dasgupta, Adv. Energy Mater.
12, 2102618 (2022).

[2] K.-H. Chen, A. J. Sanchez, E. Kazyak, A. L. Davis, N. P. Dasgupta, Adv. Energy Mater.
9, 1802534 (2019).

[3] A. L. Davis, R. Garcia-Mendez, K. N. Wood, E. Kazyak, K.-H. Chen, G. Teeter, J. Sakamoto, N. P. Dasgupta,
J. Mater. Chem. A
8, 6291 (2020)

[4] E. Kazyak, M. Shin, W. S. LePage, T. H. Cho, N. P. Dasgupta,
Chem. Commun.
56, 15537 (2020).
(Invited) Li-Free Anode Development at Quantumscape
Authors: Winterkorn Martin M , Holme Tim
Published: November 2022

QuantumScape is developing a solid-state battery with a lithium-metal anode to enable long-range, faster charging, low-cost EVs. The technology features an anode that is lithium-free as manufactured, with the lithium being delivered entirely from the cathode material. The lithium-free approach offers a significant cost savings relative to approaches that utilize an excess lithium foil or vapor deposition process. This talk will highlight the scientific and engineering challenges in developing an anode-free solid-state battery, with a historical overview and a snapshot of the progress at QuantumScape. QuantumScape was founded in 2010 with a mission to revolutionize energy storage to enable a sustainable future.
(Invited) Effects of the Alloy Composition on Cycling Performance of Cu-Ni Alloy Cathodes in All-Solid-State-Fluoride-Shuttle Batteries
Authors: Motoyama Munekazu , Sakurai Katsutoshi , Kiuchi Hisao , Nakatani Tomotaka , Nakagawa Takashi , Iriyama Yasutoshi , Ogumi Zempachi , Abe Takeshi
Published: November 2022

Metal fluorides generally have low electric conductivities. Hence, if a single metal (e.g. Cu) is used as the cathode active material for a fluoride-shuttle battery (FSB), the electric resistance in the cathode increases after the fluoridation reaction (charging).1,2 Hence, repeating charging and discharging leads to significant drop in capacity. If an alloy consisting of two metal elements with different fluorination/defluorination potentials is used as the cathode active material, one metal element behaves as a conductive metal even when the other metal element is fluorinated, and the increase in electric resistance can be suppressed. So, we evaluated Cu-Ni binary alloys as cathode active materials for FSB in this study.

The standard redox potentials (25 °C) of NiF2/Ni and CuF2/Cu are +0.11 V and +0.72 V (vs. PbF2/Pb), respectively. 3 Although NiF2 is an insulating compound, Cu behaves as a metal, providing electron conduction pathways. Additionally, the crystal structures of Cu and Ni are commonly fcc structures, with lattice constants of 3.597 Å and 3.499 Å, respectively, so that Cu-Ni alloys exhibit solid solutions in the full composition range above 380 °C in the phase diagram. Hence, the Cu-Ni alloy is considered to be an ideal alloy system that hardly separates different phases and can provide highly-dense-interconnecting-electron-conduction pathways within the whole cathode like veins.

Cu
x
Ni1−x
(x = 0, 0.3, 0.5, 0.7, 1.0) films with thicknesses of approximately 3 nm were sputter-deposited onto 0.5-mm-thick LaF3 solid electrolytes to form all-solid-state PbF2/LaF3/Cu
x
Ni1−x
cells. Charging/discharging curves and Nyquist plots of the cells were measured under high vacuum (< 10−3 Pa) at 140 °C.

Acknowledgment

This paper is based on the results obtained from projects, JPNP16001 and JPNP21006, commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

References

Okazaki et al., ACS Energy Lett.,
2, 1460 (2017).

Yamamoto et al.,
ACS Appl. Energy Mater.
,
2, 6153 (2019).

Gschwind et al., J. Fluor. Chem., 182, 76 (2016).
(Invited) High Performance of Protonic Ceramic Fuel Cell Applying Composite Cathode Functional Layer
Authors: Shim Joon Hyung , Kim Keun Hee , Yang Sung Jea , Chang Wanhyuk , Jeong Heon Jun , Kim Dong Hwan , Prinz Fritz
Published: November 2022

The performance of protonic ceramic fuel cell is improved by applying the functional layer between the cathode and the electrolyte layer. The functional layer is a composite with the cathode and the electrolyte. By inserting the functional layering utilizing thin film coating, the performance of the cell varied according to the ratio of cathode to electrolyte in composite functional layer. The results of electrochemical impedance spectroscopy and distribution of relaxation times confirmed that the polarization resistance decreases with the introduction of the functional layer. The low polarization resistance is attributed to extended triple phase boundaries at cathode-electrolyte interface.
(Invited) Effects of Support Mesoporosity on Pt Dissolution in PEM Fuel Cells
Authors: Atwa Marwa , Goh Timothy , Dull Samuel , Prinz Fritz
Published: November 2022

Interest in hydrogen as an energy carrier continues to grow due to the high demand for clean and sustainable, energy sources in the global energy market. Polymer exchange membrane fuel cells (PEMFCs) convert the chemical energy of hydrogen to electricity and have great potential as power sources for automotive applications. A key challenge in the development of cost-efficient and reliable PEMFC electrodes is catalyst layer durability. Typically, PEMFC cathodes comprise Pt-based electrocatalysts supported on high-surface-area carbons. It has been previously shown that the morphology and surface chemistry of carbon supports play significant roles in modulating both the activity and stability of Pt-based catalysts.

Here, we will present our recent efforts to investigate the effects of the porous structures and surface properties of different mesoporous carbon powders on Pt dissolution in PEMFC cathodes. Using atomic layer deposition (ALD), we fabricate cathodes by depositing Pt nanoparticles of uniform sizes and mass loadings onto mesoporous carbon supports with varying pore sizes and surface areas. We then evaluate the beginning-of-life and end-of-life performance of these cathodes after accelerated Pt dissolution tests under single cell conditions, while comparing them to a microporous Ketjenblack-based cathode as a benchmark. Based on our findings, we discuss new insights into the underlying mechanisms for Pt dissolution within the porous structures of mesoporous carbon supports.