bluuebunny/crossref_metadata_2025 huggingface dataset:
Suppressing Interfacial Degradation of Li7La3Zr2O12 Solid Electrolytes in H2O/CO2 via Polymer Encapsulation
Authors: Jeong Wooyoung , Joo Hyeonseo , Lee Ju Hyuck , Lee Jong-Won
Published: November 2022

Solid-state batteries with nonflammable inorganic solid electrolytes provide a fundamental solution for resolving safety concerns. Li7La3Zr2O12 (LLZO) has been considered as a promising candidate for solid electrolytes, due to its high Li+ conductivity and chemical/electrochemical compatibility with Li metal. However, LLZO electrolytes are known to react with H2O and CO2 to form lithium carbonates (Li2CO3) on the surface when exposed to the ambient air, resulting in the significant degradation in Li+-conduction properties. Herein, we propose an effective approach for improving the air-stability of LLZO via hydrophobic polymer encapsulation. For encapsulation of LLZO powders, polyurethane-based polymers are designed and synthesized to have high hydrophobicity and ionic conductivity by engineering soft segment and hydrophobic chain extender. Bare LLZO and polymer-encapsulated LLZO (P-LLZO) powders are subjected to accelerated durability tests (ADTs) in which the concentrations of O2, H2O, and CO2 are precisely controlled to promote the interfacial reactions. Surface characterization studies reveal that the polymer encapsulation of LLZO effectively mitigates the interfacial degradation (Li2CO3 formation) by preventing the direct contact between LLZO and H2O/CO2. Furthermore, a biphasic solid electrolyte (BSE) fabricated using ADT-tested P-LLZO powders exhibits higher ionic conductivity as compared with that of BSE with ADT-tested LLZO, proving the efficacy of the polymer encapsulation. The findings of this study would be essential in understanding the role of interfacial engineering in mitigating the degradation of Li+-conduction properties and developing highly conductive and stable LLZO solid electrolytes.
(Invited) Understanding the Evolution of Materials and Interfaces in Solid-State Batteries
Authors: McDowell Matthew T
Published: November 2022

Solid-state batteries offer improved energy density and better safety characteristics compared to lithium-ion batteries, but interfacial evolution and chemo-mechanical degradation can limit performance. In this talk, I will present my group’s recent work using in situ and operando experiments to understand nanoscale-to-macroscale evolution of materials and interfaces in solid-state batteries. Operando X-ray tomography experiments of solid-state batteries with lithium metal anodes are shown to enable real-time quantification of interfacial contact loss between lithium metal and a solid electrolyte during cycling, which is found to cause current constriction and cell failure. Deposition/stripping behavior in lithium-based batteries is also investigated in real time. Further studies reveal chemical transformations at the interface between lithium and solid electrolytes that lead to the growth of an “interphase”, which is shown to induce large stresses and to cause fracture of the solid electrolyte. Finally, reaction mechanisms in alloy-based anode materials within solid-state batteries are probed with in situ stack pressure measurements. Together, these findings show the controlling impact of the evolution of the structure, chemistry, and mechanics of the materials within solid-state batteries, with in situ and operando experiments being critical for understanding these processes.
Understanding the Electrochemical Behavior of Multi-Component Aluminum-Based Foils As Anodes for Lithium-Ion Batteries
Authors: Wang Congcheng , McDowell Matthew T
Published: November 2022

Alloy anodes are promising materials for next-generation lithium batteries. The intrinsic properties of aluminum, such as high capacity, light weight, earth abundance, and low cost, make it a competitive alloy anode candidate in lithium batteries. Furthermore, the ability to readily manufacture aluminum-based foils is an advantage for potentially simplifying battery manufacturing processes. However, utilization of Al anodes is not yet fully practical due to the capacity fading during charge and discharge. To improve cycling performance, here we fabricate aluminum alloys and composite foil structures and investigate their reversibility for Li storage in Li-ion batteries. Alloy foils including Al-Sn, Al-Zn, and Al-In were fabricated with contents ranging from 50 to 99 atomic % Al, and the electrochemical behavior of these materials as anodes for Li-ion batteries were investigated. With these materials, we studied the effects of composition, structure, and morphology on the cycling performance of the alloy foils using battery-relevant capacity metrics (areal capacity of > 2 mAh/cm2 with foil thickness < 50 microns). We show that the composition of the foils plays a significant role in determining the electrochemical cycling capability of these foils. Furthermore, the foil processing characteristics are also important in determining the achievable specific capacity, rate behavior, and cycle life of these foils anodes. This effort indicates the promise of foil-based alloy anodes and provides guidance toward engineering strategies to improve performance.
Capacity Fade and Impedance Evolution in Tin Phosphide Anodes for Sodium-Ion Batteries
Authors: L'Antigua Alex , Flannagin Megan , Nelson George J.
Published: November 2022

Sodium-ion batteries (SIBs) offer a potentially more cost effective and environmentally friendly alternative to Lithium-ion batteries for room temperature high density energy storage. To maintain the benefits of SIBs, earth abundance for all the batteries components is paramount. One promising earth abundant anode material for SIBs is tin phosphide (Sn4P3). Tin phosphides are able to retain a high specific capacity for an extended cycle life. Understanding the changes in electrochemistry within a battery as a result of cycling is crucial in the complete understanding of capacity fade mechanisms and subsequent improvement and implementation as an anode material. In this work, the main technique employed to gain this understanding is electrochemical impedance spectroscopy with distribution of relaxation times analysis (EIS-DRT). This mathematical approach to understanding traditional EIS datasets helps distinguish impedance contributions from the following processes: diffusion, counter electrodes, solid electrolyte Interfaces (SEI), and contact resistances.

Tin phosphide active material was synthesized by mechanical milling, with material structure confirmed by X-ray diffraction (XRD). Half cells were assembled with sodium counter electrodes and cycled with intermittent EIS assessment. Capacity retention was tracked during cycling to assess electrode operation. EIS-DRT analysis was performed every 5 cycles and after the end of cycling across the anode’s voltage range (0.01-1.5 V vs Na/Na+). After cycling, cyclic voltammetry (CV) and XRD were employed to further understand changes in electrochemical activity and crystal structure associated with the end of cycle life.

The evolution of impedance signatures across the initial five cycles exhibits significant shifting within the SEI and counter electrode peak at 1000 Hz. Impedance trends across the voltage range switched, in which lower voltages at higher levels of sodiation exhibit larger impedance contributions to the system. These trends are confirmed by a base understanding of SEI formation and sodiation trends. Relative impedance contributions from the diffusion process increase from pristine to cycled electrodes, with diffusion peaks at becoming the dominant impedance contribution as cycling progresses. Significant changes in DRT trends plateaued after the initial SEI formation over the first five cycles.

Abrupt and early failure during cycling of a subset of the cells was marked by a plateau in the working electrode voltage, an increase in contact resistance within EIS-DRT plots and decreased electrochemical activity within CV. Visual post mortem checks correlated well with these findings, with an apparent delamination of the electorate coating from the current collector. Understanding the physical and electrochemical phenomenon within a battery though nondestructive in situ characterization is crucial to simplify work flows in battery testing.
Reevaluating the Stability of the PEO-Based Solid-State Electrolytes for High Voltage Solid-State Batteries
Authors: Wu Xinsheng , Whitacre Jay
Published: November 2022

Poly(ethylene oxide) (PEO) is a very popular polymer-based solid electrolyte material with relatively high ionic conductivity and dielectric constant1. However, many previous works mentioned that it could not be used in high voltage cells for its low oxidation potential (~3.9V vs. Li/Li+)2. However, only a handful of prior investigations evaluated the stability of the PEO-based solid-state electrolyte considering the contribution of the cathode surface chemistry to electrolyte oxidation and decomposition. Since most of the previous research exploring high voltage cathodes with PEO used LiCoO2, it could be possible the other cathode compositions will erode the PEO-based solid electrolyte in different and less extreme ways.

Our work revisits the high voltage electrochemical stability of PEO-based solid state-electrolyte materials. Potentiodynamic and galvanostatic tests were performed in test cells using PEO electrolyte layers with either LiNixMnyCozO2 or LiCoO2 cathode materials. We found that the high voltage instability of PEO-based solid-state cells is profoundly affected by the instability of the cathode material used. Specifically, the LiCoO2 electrodes were observed to undergo an irreversible oxidation process where they shattered into small pieces, which then led to a rapid irreversible loss in capacity. In contrast, we found that the PEO-based solid-state electrolytes could be stably cycled with high-nickel content cathodes stably at a voltage up to 4.5V vs. Li/Li+ over many cycles with minimal capacity deterioration.

K. Chrissopoulou, K. S. Andrikopoulos, S. Fotiadou, S. Bollas, C. Karageorgaki, D. Christofilos, G. A. Voyiatzis, and S. H. Anastasiadis, 44, 9710–9722 (2011).

J. Qiu, X. Liu, R. Chen, Q. Li, Y. Wang, P. Chen, L. Gan, S.-J. Lee, D. Nordlund, Y. Liu, X. Yu, X. Bai, H. Li, and L. Chen, Adv. Funct. Mater., 30, 1909392 (2020).
Oxygen Vacancies of MoO3-X Nanobelts Acting As Lewis Acid Sites to Dissociate the Salt in All-Solid-State Battery
Authors: Paste Rohan , Lin Hong-Cheu , Chu Chih Wei
Published: November 2022

Lithium (Li) metal batteries are expected to develop faster to cater to the growth of the sustainable consumer electronic market. Due to its high specific capacity (3860 mAh g−1) and a low redox potential (−3.04 V vs H2/H+), Li metal is preferred to achieve high-capacity batteries. However, the Li metal is unstable and generates exothermic reactions with liquid electrolytes. The growth of Li dendrites on the surface of Li is another issue that jeopardizes the safety standards of the battery. Solid-state electrolytes can be a better alternative to achieving stable and safer Li metal batteries. Oxygen deficient metal oxides such as Molybdenum trioxide (MoO3) can act as a source of Lewis acid sites to dissociate the LiTFSI salt. We have modified a PEO-based solid-state electrolyte for stable Li-metal batteries. Locally designed MoO3-x nanobelts (MNBs) were utilized as passive fillers in PEO/LiTFSI matrix. The oxygen vacancies act like Lewis acid sites and interact with LiTFSI salt. Upon interaction, the oxygen vacancies react with TFSI− anions and separate the Li+ cations. This phenomenon enhances the number of free Li+ ions and the ionic conductivity of the PEO/LiTFSI matrix. The 5% of MNBs in PEO/LiTFSI (MPL-SPE) offered high Li-ion conductivity of 4.28 × 10−4 S cm−1 at 600C. The enhanced ionic conductivity and shorter diffusion pathways for Li+ ions result in a lower overpotential of the Li/Li symmetrical cell performance. In Figure 1a, the MPL-SPE cell shows reduced overpotential (~40mV) than the cell with PEO/LiTFSI matrix (~85mV) at a current density of 0.2mA cm-2
(Figure 1a). The as-designed MPL-SPE had attached to the cathode by using the hard press method. The cathode supported ML-SPE reduces the interfacial resistance between the cathode and solid electrolyte. The electrochemical performance of the all-solid-state Li battery with LiFePO4 (LFP) cathode attached with MPL-SPE demonstrated superior initial specific capacity of ~115 mAh g-1 and ~140 mAh g-1 at the 50th cycle at a 0.5C rate with ~100% coulombic efficiency (Figure 1b).

Figure 1
Electrochemical Characterization of a Drawn Thin-Film Glassy Mixed Oxy-Sulfide-Nitride Phosphate Electrolyte Material for Applications in Solid-State Batteries
Authors: Okkema Mary , Martin Madison , Martin Steve
Published: November 2022

Thin-film glassy solid-state electrolytes are often considered for applications in energy storage devices; fully-dense thin-film glassy electrolyte materials are able to minimize power loss while suppressing dendrite growth. The glass with the composition Na4P2S5.8O0.92N0.18 (NaPSON) was chosen because it balances the high conductivity of a sulfide chemistry with the high processability and electrochemical stability of an oxy-nitride chemistry. NaPSON thin-film glassy solid-state electrolyte ribbons with thicknesses that range from 75 to 600 μm were drawn using a process of softening and drawing of a cast and annealed preform. Raman spectroscopy was run on the thin-film samples to ensure the material was structurally similar after processing across different thicknesses and remelts. Electrochemical impedance spectroscopy (EIS) was used on varying thicknesses of thin-film to investigate and compare the ionic conductivity of Na+ in the thin film compared to the bulk sample. Area specific resistance models as a function of time were created to compare the trend of bulk and interfacial resistances of different thicknesses. Thin-film samples were made into symmetric cells and cycled. The cycling of the symmetric cells gave insight into the behavior and durability of the electrolyte under applied voltage and sustained current. These results show that drawn thin-film electrolytes are a solid research direction.
Characterizing Effect of Porous Transport Layers on Electrolyzer Performance Using Neutron Imaging
Authors: Komini Babu Siddharth , Mukundan Rangachary , LaManna Jacob Michael , Yilmaz Abdurrahman , Spendelow Jacob S. , Suarez Federico , Lee Sanghun , Schuler Tobias , Kulkarni Devashish , Stansberry John , Jacobson David , Hussey Daniel , Mauger Scott A , Bender Guido , Zenyuk Iryna V. , Khaykovich Boris
Published: November 2022

Demand for high purity hydrogen production using renewable energy sources is growing to meet the clean energy demands. Polymer electrolyte membrane water electrolyzer (PEMWE) is one of the viable options for H2 production, but its high capital cost and operational expenditures increase the cost of H2. Improving the interface between the catalyst layer (CL) and the porous transport layer (PTL) is critical to increasing the efficiency of PEMWEs and thereby lowering the cost of H2. Increased contact between the CL and PTL improves catalyst utilization, and the optimal structure of the PTL reduces the mass transport issues related to O2 bubble removal.(1-3) Improved understanding of the PTL microstructure is necessary to improve the performance and efficiency of the PEMWE.

This work presents a systematic study to elucidate the effect of PTL properties (morphology, thickness, and porosity) and their impact on PEMWE performance under different operating conditions. Polarization curves with different anode PTL (felt, sinter and pore graded hierarchical PTL) are presented in Figure 1a. The separation of mass transport resistance and the contract resistance for the different PTLs will be elucidated to show the impact of water management and interfacial contact. Mass transport in an operating electrolyzer is also studied by estimating the water content using neutron imaging. Figure 1b shows water thickness across a membrane electrode assembly (MEA) with a pore graded hierarchical PTL in anode at different current densities. Water content across the MEA with different PTL is also studied. The cells with these PTLs were evaluated in operando using micro x-ray computed tomography (CT) and x-ray radiography. The x-ray techniques revealed oxygen distribution within the PTLs on the pore-scale at varied current densities, complementing neutron imaging water thickness studies and providing micro-scale insight into transport.

Acknowledgment

This research is supported by the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office, through the H2NEW consortium.

References

J. K. Lee, C. Lee, K. F. Fahy, B. Zhao, J. M. LaManna, E. Baltic, D. L. Jacobson, D. S. Hussey and A. Bazylak, Cell Reports Physical Science, 1, 100147 (2020).

T. Schuler, J. M. Ciccone, B. Krentscher, F. Marone, C. Peter, T. J. Schmidt and F. N. Büchi, Advanced Energy Materials, 10, 1903216 (2020).

P. Lettenmeier, S. Kolb, F. Burggraf, A. S. Gago and K. A. Friedrich, Journal of Power Sources, 311, 153 (2016).

Figure 1
Tuning Catalyst-Ink Formulations for Blade Coating of Hydroxide-Exchange-Membrane Water Electrolyzers
Authors: Tricker Andrew W. , Fornaciari Julie C. , Lee Jason Keonhag , Danilovic Nemanja , Peng Xiong , Weber Adam Z.
Published: November 2022

Clean hydrogen, produced by splitting water into H2 and O2 using renewable electricity, will play a crucial role as a renewable energy carrier and in decarbonizing industrial and hard-to-decarbonize transport sectors in the future.1 Hydroxide-exchange-membrane water electrolyzers (HEMWEs) have the potential to be more cost effective compared to the incumbent technology, proton-exchange-membrane water electrolyzers (PEMWEs) through the use of cheaper and more abundant catalysts and cell components.2 However, compared to PEMWEs, HEM systems have been studied significantly less and generally have much lower performance. Here, we systematically investigated a series of pivotal parameters that are related to catalyst inks, catalyst-layer structures, and porous-transport layer/catalyst-layer interfaces for HEMWEs. An integrated reference electrode is utilized to differentiate each individual effects on the cathode and anode when studying cell performance and durability. Catalyst-ink formulations are studied by varying ionomer-to-catalyst ratios, solid concentration, and solvent compositions. Additionally, parameters around the ink coating process are explored to study their impacts on catalyst-layer structures and provide guidance on key considerations for manufacturing robust catalyst layers. Finally, the impacts of porous-transport-layer architecture and cell configuration on the cell performance are probed. The findings elucidate critical properties and highlight urgently needed experimental practices towards high-performing HEMWEs.

Acknowledgements

This work was funded under the HydroGEN 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

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).
(Digital Presentation) Nickel Iron Layered Double Hydroxide As a Promising Anode for AEM Water Electrolyzer Presenting High Performance and Durability
Authors: Galkina Irina , Jiang Wulyu , Faid Alaa Y. , Borowski Patrick , Sunde Svein , Galkina Irina , Lehnert Werner
Published: November 2022

Anion exchange membrane (AEM) water electrolyzers is an attractive alternative approach for green hydrogen production. The alkaline environment allows the use of non-PGM catalysts and, based on recent research in catalysts and membranes, may soon challenge the established proton exchange membrane water electrolyzers1,2. Transition metal-based catalysts have attracted much attention because they provide an excellent oxygen evolution reaction in alkaline media3. In particular, Ni-Fe-layered double hydroxides (LDH) have been intensively studied in recent years and have shown fast intrinsic electrocatalytic activity for water splitting4,5. In this work, we used Ni3Fe-LDH as an anode catalyst, DURAION® as ionomer and membrane and investigated the effects of electrode design and cell operation on the performance and stability of AEM electrolyzers. The optimized electrode was operated stably for 1000 hours at 1 A cm-2 with an overall degradation rate of 0.014 V h-1. At the end of the lifetime, the cell was disassembled and subjected to a series of experiments to investigate the physical and chemical degradation.

This work provides a fundamental understanding and specific approach to the use of nickel-iron-based electrodes and promotes the further development of AEM water electrolyzers through highly stabilized, Ni-rich, and low-cost anodic electrocatalysts.

This work has been performed in the frame of the CHANNEL project. This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under grant agreement No 875088. This Joint undertaking receives support from the European Union's Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research.

Vincent, I. & Bessarabov, D. Low cost hydrogen production by anion exchange membrane electrolysis: A review. Renew. Sustain. Energy Rev.
81, 1690–1704 (2018).

Miller, H. A. et al. Green hydrogen from anion exchange membrane water electrolysis: A review of recent developments in critical materials and operating conditions. Sustain. Energy Fuels
4, 2114–2133 (2020).

Gong, M., Wang, D. Y., Chen, C. C., Hwang, B. J. & Dai, H. A mini review on nickel-based electrocatalysts for alkaline hydrogen evolution reaction. Nano Res.
9, 28–46 (2016).

Zignani, S. C., Faro, M. Lo, Trocino, S. & Aricò, A. S. Investigation of NiFe-based catalysts for oxygen evolution in anion-exchange membrane electrolysis. Energies
13, (2020).

Mohammed-Ibrahim, J. A review on NiFe-based electrocatalysts for efficient alkaline oxygen evolution reaction. J. Power Sources
448, 227375 (2020).
Formation of Three-Dimensional Ion Transport Channels in Composite Solid Polymer Electrolyte for Use at Room Temperature
Authors: Nguyen An-Giang , Song Geon-Chang , Park Chan-Jin
Published: November 2022

Lithium-ion batteries (LIBs) have widely revolutionized our lifestyle, from electronic devices and electric vehicles (EVs) to energy storage systems (ESSs) along with decarbonization trends for sustainable perspective. Unfortunately, the future application of conventional LIBs using liquid organic electrolytes has shown limitation in terms of their energy density and safety concerns. All-solid-state battery (ASSB) are attractive as a next-generation battery to address these issues. Among various solid-state electrolytes, composite solid polymer electrolyte (CSPE) is of particular interest by inheriting the advantages of both inorganic and solid polymer electrolytes. The CSPEs are generally constructed by dispersing (in)active fillers into the polymer matrix to facilitate the dissociation of lithium salts and decrease the crystallinity of polymer matrix, leading to an increase in the ionic conductivity of CSPEs. To further improve the ionic conductivity of CSPEs, the fillers with various morphologies from 0D, 1D, 2D, and 3D frameworks can be used to enhance the conductive pathways for lithium-ions diffusion. In particular, the 3D frameworks greatly improved ionic conductivity by supplying “highways” for lithium-ion diffusion. In addition, 3D frameworks can also prevent the agglomeration of filler particles and the growth of lithium dendrite.

In this study, by employing a 3D ionic transport framework, Li|3D-CSPE|Li symmetric cell could cycle over 1000 h at a current density of 0.1 mA cm-2. Moreover, all-solid-state Li|3D-CSPE|LiNi0.8Co0.1Mn0.1O2 cell retained a high capacity retention of 79.4% after 230 cycles at 30 °C. In addition, this novel concept is successfully applied to all-solid-state sodium batteries. The Na|3D-CSPE| Na3V1.97Mg0.03(PO4)3/C cell demonstrateed long-term cycling stability at 2 C. This approach provides a practical strategy to address the bottleneck of CSPE to enable safe and high-energy solid-state batteries.
Printable Lithium - LIOVIXTM Assisted All Solid-State Lithium-Ion and Lithium-Metal Batteries for Enhanced Electrochemical Properties
Authors: Black Rebecca , Navulla Anantharamulu , Fitch Brian , Xia Jian , Watson Andrew , Cabaniss Joseph Emory , Reid Julian , Yakovleva Marina
Published: November 2022

All solid-state lithium-ion and lithium-metal batteries, which utilize a solid electrolyte in place of liquid electrolytes, are considered next-generation devices for energy storage due to their advantages in safety and potentially higher energy density. However, currently many solid-state lithium-ion and lithium-metal batteries are limited by their low Coulombic efficiency, poor power performance, and short cycling life due to the high resistance at the solid-state interfaces. Because of the diverse physical, chemical, and mechanical properties of various solid components in all solid-state batteries as well as the nature of solid-solid contact, many types of interfaces are present in a solid-state battery that can result in loose physical contact, formation of grain boundaries, and undesired chemical and electrochemical side reactions. All of these contribute to increasing resistance at the interface, which diminishes the cell performance, making solid state batteries not suitable for practical application.

LIOVIXTM is a unique printable formulation of lithium metal and other specialty materials, which can be used in both lithium-ion and lithium metal-based rechargeable batteries. In the case of lithium-ion batteries, it can be printed on a range of anode materials including silicon-containing anodes for the pre-lithiation process to improve the first cycle columbic efficiency and cell performance. In the case of lithium metal-based batteries, LIOVIXTM can be printed directly onto the current collectors or solid electrolyte separators to fabricate all solid-state batteries utilizing printed lithium metal anodes. This approach has the potential to enable improved performance, safety, recyclability, and lower cost compared to the current advanced lithium-ion systems. In both categories, printable lithium formulation can reduce the interface resistance between the anode and solid electrolyte layer, which enhances the cell performance enabling practical application. The printable lithium formulation is easily scalable using industry standard coating and printing equipment and is adaptable to any anode or cathode chemistry where an independent source of lithium is required. In addition, the lithium loading can be accurately controlled based on the applications’ requirements. We have demonstrated improved electrochemical performance of silicon containing anodes with liquid electrolytes in a full cell format. The present work will demonstrate the concept of all solid-state batteries incorporating printable lithium with enhanced electrochemical properties compared to conventional solid-state batteries.
Understanding Ion-Exchange Reaction Mechanisms in Layered Oxide Cathodes for Beyond Li-Ion Batteries
Authors: Kim Haegyum , Byeon Young-Woon
Published: November 2022

Ion-exchange reactions are frequently used to develop novel metastable electrode materials for alkali-ion batteries that cannot be synthesized using direct chemical reactions. In fact, the ion-exchange reaction has been proven as an effective approach to develop novel transition metal oxide cathodes for lithium, sodium, and potassium ion batteries.[1-4] However, the solid-state ion-exchange mechanism and the resulting phase evolution are barely understood. In this work, we investigated the electrochemical ‘K-to-Na’ and ‘Na-to-K’ ion-exchange reaction mechanisms in layered oxide cathodes as it occurs using operando and ex situ structure characterization techniques.[5-6] Our study demonstrates that the ion-exchange occurs not by a simple Na/K interdiffusion in a given host structure. Instead, we discovered intriguing multi-phase evolutions according to the relative Na/K content, indicating that the ion-exchange systems may be more complex to interpret than the previously understood. We found that not only Na (or K)-layered oxide host interaction but also Na-K interaction affect the ion-exchange reactions. In this presentation, we will discuss how and why those parameters determine the ion-exchange reactions and resulting phase evolutions.

References

[1] S. Baskar et al. ECS Transactions
2017, 80, 357.

[2] N. Naveen et al. Chem. Mater.
2018, 30, 2049.

[3] C, Delmas et al. Mater. Res. Bull.
1982, 17, 117.

[4] A. R. Armstrong et al. Nature
1996, 381, 499.

[5] H. Kim et al. Chem. Mater.
2020, 32, 4312.

[6] H. Kim et al. Energy Storage Materials.
2022, 47, 105
A Facile, Lithium Salt in Polymer Interfacial Layer for Lithium Anode Stability in Lithium-Sulfur Batteries
Authors: Yim Taber , Cardoza Neal A. , Pereira Rhyz , Kalra Vibha
Published: November 2022

Lithium-sulfur batteries (LSBs) have garnered interest recently due to their 8-fold increase in theoretical capacity compared to state-of-the-art Li-ion batteries (LIBs), the affordability of sulfur at $100/ton, and the low environmental impact of sulfur. However, just like LIBs, LSBs suffer from anode instability due to dendrite formation and an unstable solid electrolyte interface (SEI). In this work, we address anode stability via a facile, polymer and lithium salt interfacial layer. Stable SEI formation was achieved by using a fluorinated polymer and lithium salt. A conventional Celgard separator was used for mechanical support and the polymer:salt ratio was tuned. To confirm the effectiveness of the interfacial layer for anode stability, it was used as a standalone gel polymer electrolyte in a Li-Li symmetric cell. It showed remarkable stability beyond 700 hours at an energy density of 1 mA cm-2 and capacity of 1 mAh cm-2, with a steady polarization voltage of 16mV. By comparison, a Li-Li symmetric cell with a Celgard separator began to show increasing polarization voltage after just 100 hours, with a polarization voltage that gradually increased to beyond 500mV (Figure 1). This stability was achieved by a robust SEI layer that contained LiF and Li2O, hindering the formation of the dead lithium layer. The presence of these compounds was confirmed by post-mortem X-ray photoelectron spectroscopy. Dendrite formation was also physically inhibited by the presence of the polymer matrix that had a uniform morphology and pore diameter around 1 μm. Additionally, using this interfacial layer in a lithium-sulfur coin cell provided a capacity of 866 mAh g-1 at 200 cycles, a 26% improvement over lithium-sulfur cells without the interfacial layer.

Figure 1
MOF-Derived Nanoporous Carbon As an Efficient Bifunctional Oxygen Electrocatalyst for Erzabs
Authors: T Saranya , Mathialagan Kowsalya , Dixon Ditty , Bhaskar Aiswarya , Nishanthi S.T
Published: November 2022

Zinc-air batteries are cost-effective batteries that possess a high energy density (1086 Wh Kg-1), compared to other conventional battery systems. In order to improve the electrochemical performance of electrically rechargeable zinc-air batteries (ERZABs), an effective bifunctional oxygen electrocatalyst is required. Hence, the development of non-noble metal bifunctional catalysts for ORR and OER is of prime importance. The transition metal-based catalysts have increasing demand since they are promising alternatives, in terms of cost and durability, to noble metal catalysts. Metal-organic frameworks (MOF) based catalysts show high catalytic activity due to adjustable pore size, ultra-high surface area, and structural designability[1].Increasing porosity can augment the catalytic activity by increasing the surface area, thereby enhancing the ORR kinetics.

In the present work, a CFZ-NPC (CoFeZn-MOF derived nanoporous carbon) was synthesized via hydrothermal method and investigated as a bifunctional catalyst for rechargeable zinc-air batteries[2]. The catalyst shows a high electrochemical activity towards oxygen reduction reaction with a half-wave potential of 830 mV vs. RHE and a comparable oxygen evolution activity (overpotential of 379 mV vs. RHE at 10 mA cm-2 ) with IrO2 (Over potential of 377 mV at 10 mA cm-2). The binder-free CFZ-NPC air electrode when applied into a Zinc-air battery system, delivers a low charge-discharge potential gap of 862 mV at 5 mA cm-2. Interestingly, the catalyst possesses an excellent electrochemical performance in the electrically rechargeable Zn-air battery over 1000 cycles at selected DOD for 157 h with a specific capacity of 890 mAh g(Zn)
-1 without much efficiency drop.

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

References;

[1] Ren, Shuangshuang et al. 2020. “Bifunctional Electrocatalysts for Zn-Air Batteries: Recent Developments and Future Perspectives.” Journal of Materials Chemistry A 8(13): 6144–82.

[2] Tang, Jing et al. 2016. “Bimetallic Metal-Organic Frameworks for Controlled Catalytic Graphitization of Nano porous Carbons.” Nature Publishing Group (April): 1-8.
(Invited) The U.S. Department of Energy’s Hydrogen Energy Earthshot: Addressing Important Challenges and Opportunities in the Research, Development, Demonstration, and Deployment of Clean Hydrogen Technologies
Authors: Miller Eric
Published: November 2022

On June 7th of 2021, Secretary of Energy Granholm announced the Hydrogen Energy Earthshot (also know as the Hydrogen Shot) - an initiative to enable clean, low cost hydrogen within a decade. In addition, the Bipartisan Infrastructure Investment and Jobs Act (IIJA), signed by President Biden in November of 2021, includes $9.5 billion for clean hydrogen, which is made up of $8 billion for at least four regional clean hydrogen hubs and $1.5 billion for electrolysis and clean hydrogen manufacturing and recycling research, development, and demonstration. In addition to accelerating the research, development, demonstration, and deployment of clean hydrogen technologies (including foundational electrochemical process for production and utilization), these investments are expected to provide exciting regional opportunities for jobs creation, economic growth, energy independence, and environmental justice. The presentation will discuss key challenges and major opportunities being addressed through the U.S. Department of Energy’s Hydrogen Program (coordinated through its Hydrogen and Fuel Cell Technologies Office); with the aggressive but achievable ten-year goal put forward by the Hydrogen Shot of $1 for 1 kg of clean hydrogen.
(Invited) Concentrated Hydrogen Bonded Electrolytes with Ferrocene and Viologen for Redox Flow Batteries
Authors: Gurkan Burcu , Ghahremani Raziyeh , Dean William , Sinclair Nicholas Scott , Savinell Robert F. , Wainright Jesse S.
Published: November 2022

We developed concentrated hydrogen bonded electrolytes (CoHBEs) derived from a mixture of choline chloride (ChCl) and ethylene glycol (EG) containing ferrocene and viologen redox species for redox flow batteries. CoHBEs are similar to deep eutectic solvents (DESs) in terms of having distinct physical properties including wide electrochemical window, and low volatility. However, CoHBEs do not necessarily meet the requirement of “deep eutectic temperature” at a specific composition of the parent compounds that form the DES. CoHBEs formed with viologen and ferrocene species in ChCl:EG demonstrate reversible redox reactions. More importantly, 0.5 M of a viologen derivative coupled with 1 M of a ferrocene derivative was achieved owing to the good solvent strength of ChCl:EG at 1:4 and 1:6 compositions. The resulting electrolyte presents about 2M equivalent concentration of the redox couple since the viologen derivative is able to undergo two successive electron transfer. A theoretical cell voltage of 1.35V is possible with this electrolyte. This presentation will discuss the electrochemical and transport properties of this electrolyte system, and their applicability in redox flow batteries as studied by spectro-electrochemical and flow cell experiments.
Enhancement of Li-Mediated Electrochemical Ammonia Synthesis By Modifying Main Element of Ylide Proton Shuttle
Authors: Yang Sungbin , Shin Byungha
Published: November 2022

Ammonia is an essential chemical used various fields including agriculture and chemical engineering. It is also considered as one of the candidates for carbon-free hydrogen storage. Electrochemical nitrogen reduction reaction (ENRR) has been studied as an alternative to current energy-intensive and greenhouse gas emitting Habor-Bosch process. Lithium mediated nitrogen reduction reaction (Li-NRR), in which organic compounds replace water as the proton shuttle, is currently considered as the most promising route in terms of ammonia production rate. However, ethanol (EtOH), acommon proton shuttle in Li-NRR, has a limited electrochemical stability because it is prone to oxidation at the anode or can be consumed by forming byproducts at the cathode. Therefore, it is highly desirable to search for alternative proton shuttles. In this study, two different ylides—namely, tetrabutylphosphonium chloride (TBPCl) and tetrabutylammonium chloride (TBNCl)—were selected as the proton shuttle in place of EtOH. Both compounds showed spontaneous reaction with lithium nitride by forming ammonia. Both TBPCl and TBNCl showed a higher ammonia production rate and faradaic efficiency than EtOH. Interestingly, tetrabutylammonium chloride showed higher ammonia production rate than tetrabutylphosphonium chloride which may originate from the difference of the acidity. This work demonstrates the possibility of using ylides as an effective proton shuttle and points out the important role of the center atom of the ylides in Li-NRR.
(Invited) Oxygen Evolution Behavior of La1−X
Sr
x
FeO3−

δ
Electrodes in LiCl-KCl Melt
Authors: Kimura Shunichi , Fukumoto Takashi , Suzuki Yuta , Fukunaka Yasuhiro , Goto Takuya
Published: November 2022

Electrochemical reduction processes of oxides and injected CO2 in molten salt have been paid much attention as the carbon free technology to achieve the SDGs. We focused on La1−
x
Sr
x
FeO3−

δ
materials to utilizing O2 evolution electrode, because they intrinsically possess both oxygen ion conductivity and electron conductivity at elevating temperatures. Unfortunately, the properties have not been well examined in the molten salt despite the fundamental characteristics for the application to the inert anode. We found that La1−
x
Sr
x
FeO3−

δ
electrodes had excellent chemical and physical stability for keeping stable oxygen evolution reaction in the molten chlorides at 723 K.
Superionic Conducting Triple-Doped Stabilized Bismuth Oxide for High Performing Reversible Solid Oxide Cells
Authors: Yu Hyeongmin , Kim Doyeub , Jeong Incheol , Im Ha-Ni , Lee Kang Taek
Published: November 2022

Reversible solid oxide cells (SOCs) have drawn much attention as alternative energy conversion and storage devices owing to their high efficiency and environmental benignity. However, considering their high operating temperature involves unwanted chemical reactions, thermal stress, and high system costs it is essential to lower their operating temperature for commercial feasibility. At reduced temperature, on the other hand, the catalytic activity of oxygen reduction reactions (ORRs), oxygen evolution reactions (OERs), and oxygen ionic transport are diminished due to their thermally activated nature. For example, the most widely used yttria-stabilized zirconia (YSZ) shows significantly decreased ionic conductivity at reduced temperature (e.g. 0.003 S/cm at 600 °C), which is not sufficient for high performing SOCs.

Among various alternative oxygen ionic conducting materials, rare-earth stabilized bismuth oxides have been well known as super ionic conductors which exhibit 30 times higher conductivity than that of YSZ. However, the ionic conductivity of stabilized bismuth oxides is significantly decreased due to their phase transformation from cubic phase to rhombohedral phase at 600 °C. In this regard, it is crucial to carefully utilize proper doping material for enhancing their stability while retaining their high ionic conductivity.

In this study, we newly developed stabilized bismuth oxide with superior ionic conductivity and durability at 600 °C via triple-doping strategy. Initial ionic conductivity of the stabilized bismuth oxide was maintained for more than 1000 hours at 600 °C with no phase transformation. This stabilized bismuth oxide was combined with conventional La0.8Sr0.2MnO3-
δ (LSM) as a novel oxygen electrode. Furthermore, a SOC with this novel air electrode showed high electrochemical performance both in the fuel cell (FC) and the electrolysis (EC) modes (e.g. 2.5 W/cm2 and 1.4 A/cm2 at 1.3V at 700 °C in the FC and the EC modes, respectively).
Sulfur- and Coking-Tolerant Anodes for Solid Oxide Fuel Cells
Authors: Liu Zhijun , Zhou Yucun , Zhang Weilin , Hou Jie , Hu Xueyu , Liu Meilin
Published: November 2022

Sulfur- and Coking-tolerant Anodes for Solid Oxide Fuel Cells

Zhijun Liu,1 Yucun Zhou,1 Weilin Zhang,1 Jie Hou,1 Xueyu Hu,1 Meilin Liu1, *

1
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States

Abstract

Solid oxide fuel cells (SOFCs) have potential to be one of the most efficient systems for direct conversion of a wide variety of chemical fuels into electricity. 1-3 However, the lack of sulfur- and coking-tolerant anodes still hinders the development of direct hydrocarbon-fueled SOFCs for efficient and cost-effective operation. The conventional Ni-based anodes may suffer from carbon deposition and sulfur poisoning when they are directly exposed to sulfur-containing hydrocarbon fuels, resulting in degradation in performance or even destruction of the anodes. 4-6 In this presentation, we will report a conventional Ni-Zr0.84Y0.16O2-δ (YSZ) anode decorated with Ce and Ba-based catalyst coatings to significantly enhance the sulfur and coking tolerance. Results suggest that the enhanced sulfur tolerance is attributed to the evenly distributed Ce-based catalyst on the inner surface of the porous Ni-YSZ anode while the enhanced coking tolerance is benefited from the Ba-based catalyst layer on the top of the anode. SOFCs with the catalysts-modified Ni-YSZ anodes show minimal degradation when hydrogen with 100 ppm H2S is used as the fuel. More importantly, stable operation is demonstrated for direct utilization of sulfur-containing liquid fuels (e.g., octane and gasoline). This work demonstrates the great potential of catalyst coatings for enhancing contaminant tolerance and durability of SOFC electrodes.

Z. Wang, Y. Wang, D. Qin, Y. Gu, H. Yu, S. Tao, B. Qian and Y. Chao, J. Eur. Ceram. Soc. (2022).

S. Sengodan, M. Liu, T.-H. Lim, J. Shin, M. Liu and G. Kim, J. Electrochem. Soc., 161, F668 (2014).

Z. Cheng, J.-H. Wang, Y. Choi, L. Yang, M. C. Lin and M. Liu, Energy Environ. Sci., 4, 4380 (2011).

T. Hays, A. M. Hussain, Y.-L. Huang, D. W. McOwen and E. D. Wachsman, ACS Appl. Energy Mater., 1, 1559 (2018).

Y. Chen, B. deGlee, Y. Tang, Z. Wang, B. Zhao, Y. Wei, L. Zhang, S. Yoo, K. Pei, J. H. Kim, Y. Ding, P. Hu, F. F. Tao and M. Liu, Nat. Energy, 3, 1042 (2018).

L. Yang, S. Wang, K. Blinn, M. Liu, Z. Liu, Z. Cheng and M. Liu, Science, 326, 126 (2009).
A Self-Forming CO2/O2 Co-Transport Dual-Phase Membrane for Oxidative Coupling of Methane
Authors: Zhang Kangkang , Sun Shichen , Huang Kevin
Published: November 2022

Direct methane conversion (DMC) has garnered considerable interest from both industries and academia in recent years due to its great economic potential created by significantly increased price differential between low-cost natural gas (NG) and the derived value-added chemicals. Oxidative coupling of methane (OCM), which transforms CH4 into ethylene (C2H4) with molecular O2 as the oxidant in a single step, is one of the most studied DMCs. However, a major technical challenge for the OCM process is the difficulty to achieve high CH4 conversion at high C2 (ethane or ethylene) selectivity. The rudimentary cause for this “tradeoff” behavior is that the products (C2H6 or C2H4) are chemically more reactive than the reactant (CH4). To overcome this thermodynamic hurdle, minimizing the oxidizing power of the oxidant or lowering the local oxygen partial pressure is key. In this presentation, we show a CO2/O2 co-transport membrane reactor for OCM conversion. The results explicitly show that the permeated O2 can react preferably with CH4 as in the conventional OCM to form C2H6; the latter then undergoes thermal cracking into C2H4 and H2. The roles of the permeated CO2 are assumed to be reacting with H2 via reverse water gas shift (RWGS) reaction to shift the C2H6 thermal cracking; another role of CO2 is assumed to be mitigating coke formation via Boudouard (RB) reaction.
Degradation and Reactivation of Ni-Doped Strontium Iron Titanate Solid Oxide Cell Fuel Electrodes
Authors: Zhang Yubo , Schmauss Travis Anthony , Barnett Scott A
Published: November 2022

Compared with conventional cermet solid oxide cell fuel electrodes, perovskite electrodes have the advantages of redox stability, coking resistance and sulfur resistance. Moreover, cation exsolution, where metal nanoparticles exsolve from the parent perovskite oxide under reducing conditions, has been shown to significantly enhance the electrochemical performance of the perovskite fuel electrodes due to the surface decoration of highly dispersed, catalytically active metal nanoparticles. Unfortunately, the phase transition of perovskite electrodes with time under different fuel conditions and its effect on their durability have not been fully understood. Furthermore, the phase and microstructure transformation of these exsolved perovskite electrodes under redox cycles still need more investigation.

Here durability test of Ni-doped strontium iron titanate (STFN) was conducted at 850oC under different fuel conditions and redox cycles were introduced during these life-tests. Degradation in both ohmic resistance (R0) and polarization resistance (Rp) was observed during aging in 97% H2 + 3% H2O, and the introduction of wet Ar after 240-hour aging successfully recovered some of the electrochemical performance of STFN. In-situ X-ray diffraction shows the formation of Ruddlesden-Popper phase together with Ni-Fe alloy exsolution upon exposing to 97% H2 + 3% H2O and the change in composition over time was also observed. Scanning electron microscopy also shows coarsening of exsolved nanoparticles and microstructural change of perovskite electrodes. Moreover, life tests of STFN were also conducted in 50% H2 + 50% H2O and 50% H2 + 50% H2O at 850oC. Despite the more Ni-rich exsolved nanoparticles due to the higher oxygen partial pressure, the durability was worse than that of 97% H2 + 3% H2O. The increased degradation rate was attributed to the microstructural change of the parent perovskite phase.