bluuebunny/crossref_metadata_2025 huggingface dataset:
Extending Operation Temperature of Hydrogel for Zn Ion Batteries
Authors: Wang Peng , Andrei Petru
Published: September 2023

Aqueous zinc ion batteries (ZIBs) provide one of the most promising technologies for large-scale electrochemical energy storage because they are environmentally friendly, safe, and have a low-cost. However, there are still some major challenges for the commercialization for ZIBs, such as Zn dendrite on Zn anode surface and poor low-temperature operation. The major problem related to the operation at low temperatures is that the water freezes below 0 C as a result of the bonding between the water molecules, especially the H-bond in the aqueous electrolyte. Modifying the solvation structure by using additives and concentrated electrolytes is among the most efficient ways to widen the operation temperature range of the aqueous electrolyte. In this presentation, we developed a hydrogel made from a commercial material, para-aramid fiber, combined with polyvinyl alcohol showing excellent anti-freezing performance even at -40 C. Due to the abundant and uniformly distributed hydrophilic oxhydryl on the polymer chain, the hydrogel is able to facilitate ion absorption and dissociation to promote the ion transport. The competition between water molecules and hydrophilic oxhydryl can improve the anti-freezing performance of the hydrogel. Our hydrogel demonstrates superior mechanical properties and high ionic conductivity down to -40 C, which opens the horizons for operating these batteries in large-scale energy storage at high latitudes. In addition, the developed hydrogel shows good protection to the Zn anode by preventing Zn dendrite growth and prolonged the lifetime of the Zn symmetric cell at both room and below-room temperatures.
LTO/TiO2 Nanowire-Decorated on Graphite Felt As Electrode for High-Performance Vanadium Redox Flow Battery
Authors: Huang Zih-Jhong , Kabtamu Daniel , Wang Chen-Hao
Published: September 2023

Vanadium redox flow battery(VRFB) is one of the most promising large-scale energy storage systems. However, the graphite electrode materials employed for VRFB often have shortcomings such as poor electrochemical activity and insufficient conductivity, which will lead to poor performance of VRFB. To modify the graphite electrode, in this study, lithium titanate/titanium dioxide(LTO/TiO2) composite catalyst with the nanowire morphology was directly grown on the surface of the heat treatment graphite felt(HGF). The graphite felt electrode through the nanowire morphology, the reaction area between the electrode and the electrolyte and active sites are increased, thereby improving the performance of VRFB.

In order to further prove the effect of lithium titanate/titanium dioxide composite catalyst modified graphite felt(LTO/TiO2@HGF), the modified graphite felt electrode was applied to the positive and negative electrodes of VRFB, and the charge and discharge tests at different current densities were carried out. In terms of efficiency, the LTO/TiO2-modified graphite felt electrode has obviously better results. When the current density is increased to 200 mA/cm2, its energy efficiency can reach 60.57%, which is 8.63% higher than that of HGF. In the stability test with a current density of 160 mA/cm2, the VRFB was charged and discharged for 60 cycles, and the overall performance did not change significantly, which means that the composite material of lithium titanate and titanium dioxide not only effectively improve the performance of the VRFB, but also show the stability that can be used for a long time.
Thermally Conductive Nitride-Based Ceramic-Coated-Separator for Lithium-Ion Batteries
Authors: Choi Seungyeop , Roh Youngjoon , Kim Ucheol , Lee Yong Min
Published: September 2023

As the demand for electric vehicles (EVs) increases, a lot of research to achieve high-energy-density lithium-ion batteries (LIBs) is being actively conducted. However, charging an EV, which takes longer than refueling an internal combustion engine vehicle (ICEVs), is still a common concern. As a way to address this problem, high-rate charging can lead to heat accumulation inside LIBs. In particular, in the case of polyolefin-based separators such as polyethylene and polypropylene, which are currently widely used in LIBs, their low melting temperature threatens the safety of cells during fast charging. To compensate for the low thermal stability of these polyolefin-based separators, ceramic-coated separators (CCS), in which a ceramic coating layer is introduced on the surface of the separator, have now become an essential component for securing the safety of LIBs. Nevertheless, conventional oxide- or hydroxide-based ceramic materials such as Al2O3, Mg(OH)2, AlOOH, etc. still have low thermal conductivity to suppress the heat accumulation especially in large-scale LIBs. Thus, CCSs were fabricated using a nitride-based ceramic material having excellent thermal conductivity. After the CCS was prepared, air permeability, ionic conductivity, thermal stability, and adhesion properties of the ceramic coating layer were measured to be compared with those of Al2O3-based CCSs. In addition, the thermal conductivity of nitride- and oxide-based CCSs are compared to confirm the possibility to improve the heat dissipation characteristics of the LIBs.
Electrocatalytic, Homogeneous Ammonia Oxidation in Water to Nitrate and Nitrite with a Copper Complex
Authors: Liu Han-Yu , Lant Hannah M. C. , Troiano Jennifer L. , Hu Gongfang , Mercado Brandon Q. , Crabtree Robert H. , Brudvig Gary W.
Published: September 2023

Electrocatalytic ammonia oxidation (AO) at room temperature and pressure allows energy-economical and environmentally-friendly production of nitrites and nitrates. Few molecular catalysts, however, have been developed for this six- or eight-electron oxidation process. We now report [Cu(bipyalk)]+, a homogenous, earth-abundant metal electrocatalyst that realizes the title reaction in water. The complex selectively catalyzes the ammonia oxidation electrochemically at 94% Faradaic efficiency without generating the less-valuable N2 product commonly seen in molecular AO catalysis. Moreover, our complex is designed to not mediate water oxidation (WO), which is beneficial for high selectivity in AO in aqueous media. Initial mechanistic studies by electrochemistry propose monometallic catalysis and water or ammonia-nucleophilic attack for N–O bond formation.

Figure 1
GC:BiFE As an Useful Tool for the Quantification of Health Harmful Organic Compounds in Artisanal Spiritus Beverages Via ADSV
Authors: Chávez-Vera Sara , García-Bassoco David , Frontana-Uribe Bernardo Antonio
Published: September 2023

The bismuth film electrode (BiFE) has been used for the last two decades to substitute mercury electrodes for organics and inorganic compounds electroanalysis in the ppm and ppb range. Various of these compounds are considered such as important pollutants and potentially toxic for the human health. The electrode specificity is based in the ability to form amalgams or strong interactions with the analyte under test. The present work show the application of BiFE for detection and quantification of acetaldehyde (by-product of alcoholic fermentation) in EtOH:H2O (1:1).The analysis is carried out using Cathodic Adsorptive Stripping Square Wave Voltammetry (CAdSSWV) to take advantage of the ability to form strong interactions and the sensitivity of this technique.

Fig 1. CAdSSWV of formaldehyde 50 ppm in EtOH:H2O (1:1) in LiClO4 0.1 M with acetate buffer (pH=4.5) as supporting electrolyte in BiFE supporting in Glassy Carbon. Edep= 0.2 V tdep=60 s. Reference electrode = Ag/AgCl Auxiliar electrode = Tungsten wire

References

Hutton, E., Ogorevc, B., Hocevar, S., Weldon, F., Smyth, M., Wang, J., An introduction to bismuth film electrode for use in cathodic electrochemical detection, Electrochem. comm., 2001, 3, 707 – 711 DOI: 10.1016/S1388-2481(01)00240-5

Constant, M. G. Van den Berg, Jacinto Gil S., The determination of platinum in sea water by adsorptive cathodic stripping voltammetry, Analytica Chim. Acta, 1988, 129 – 139 DOI: 10.1016/S0003-2670(00)83675-2

Figure 1
Preparation and Physicochemical Characterization of Phosphonium-Based Ionic Liquids Containing Carboxylate Anions
Authors: Akamatsu Hyoma , Tsunashima Katsuhiko , Tsuchida Yusuke , Okuno Yoshiharu , Yamada Hirohisa
Published: September 2023

Ionic liquids (ILs) are organic salts composed of cation and anion with melting points below 100°C. They have unique characteristic features.1) ILs are also promising liquid materials available for various applications because their function can be easily controlled by changing the combination of cations and anions and by introducing substituents. Among the numerous ILs, considerable ILs based on carboxylate anions have been reported. On the other hand, several published papers reported ILs based on quaternary phosphonium cations, demonstrating relatively high transport properties and thermal stability2). We report here the preparation and physicochemical properties of ILs based on triethyloctylphosphonium (P2228) and tributyloctylphosphonium (P4448) cations together with various carboxylate anions.

The intermediate hydroxides were obtained by adding an anion exchange resin (Amberlite IRN78 OH) into the precursor bromide aqueous solutions. Equimolar amounts of carboxylic acids (formic, acetic, propionic, butyric and octanoic acids) were added to the hydroxide solutions to form carboxylate-based phosphonium salts. The salts obtained were isolated by evaporation and then were dried under high vacuum at 50 °C. The physicochemical properties of ILs, e.g. density, viscosity, conductivity and thermal decomposition temperature were measured.

Table 1 shows the physicochemical properties of the ILs at 25 °C. P2228-PrCO2 became a solid at room temperature, while P2228-HCO2, P2228-MeCO2, and P2228-EtCO2 became viscous liquids at room temperature. Furthermore, all P4448-based salts became viscous liquids at room temperature. The density of each IL was increased with decreasing the carbon numbers of the alkyl chains in carboxylate anions. The number density also showed similar tendency to the density. These results indicate that the number density of the formate was the highest since the anion size was the smallest. The viscosity of each ILs was decreased with increasing the carbon numbers of the alkyl chains in carboxylate anions. Although the details of the relationship between measured viscosity and the carbon numbers of the alkyl chains in carboxylate anions still remain unclear at present, it is thought to be the charge distribution of the anions is one of the factors. The acetate-, propionate-, butyrate-, and octanoate-based ILs showed high thermal decomposition temperatures around 270 to 300°C. However, the formate-based ionic liquid showed lower thermal stability, which might be due to the decarboxylation of the formate anion.

Figure 1
(Invited) Performance Improvement of Unitized Reversible Fuel Cell Systems
Authors: Ito Hiroshi , Nakano Akihiro
Published: September 2023

A pilot-scale unitized reversible fuel cell (URFC) system was installed in our laboratory (AIST) and its efficiency was comprehensively evaluated. In AIST, URFCs were originally developed for load leveling and cogeneration in commercial buildings, but they are also promising for space applications. This URFC system was composed of a proton exchange membrane (PEM)-based cell/stack and balance of plant (BOP) adaptable for both electrolysis (EL) and fuel cell (FC) operation modes. The efficiency of this URFC system was evaluated at both the stack level and system level. Then, the calculated efficiency of the URFC system at each operation mode was compared with that of specialized devices of PEM electrolyzer and PEM fuel cell as reference standards. The comparison reveals that the stack performance of the EL operation modes of the URFC were comparable to that of the specialized device of PEM water electrolyzer, though, the performance of the FC operation modes of the URFC was clearly inferior to that of PEM fuel cell. The difference in performance in the FC mode was mainly due to the larger membrane thickness of the PEM in URFC. We propose measures to solve this problem and further improve performance in both modes of operation.
(Keynote) Electrochemistry on Mars – Two Years of MOXIE (Mars Oxygen ISRU Experiment) Operations Producing Oxygen on the Surface of the Red Planet
Authors: Hoffman Jeffrey A.
Published: September 2023

By the time of the 243rd ECS, NASA’s Mars2020 Perseverance rover will have spent over two Earth years on the surface of Mars, during which time the MOXIE experiment (Mars OXygen ISRU Experiment) will have produced oxygen at night and in the day during both the annual maximum and minimum atmospheric density periods, as well as at many other times during the year. MOXIE is the first demonstration of the use of indigenous resources (ISRU = In Situ Resource Utilization) on the surface of another planet. This talk will explain how MOXIE works and will present a summary of what MOXIE has accomplished, how its performance on Mars has changed with time, and plans for the future. The paper will also present results from an optimization study of a human-scale MOXIE-type system capable of providing the oxidizer for a 6–person Mars Ascent Vehicle. As an experiment carried inside the rover, MOXIE had to satisfy many constraints that would not apply to an independent, full-scale system. Other potential oxygen-producing technologies should be compared to the optimized human-scale system results summarized in this paper rather than to a simple linear scaling of the mass, power consumption, and oxygen production rate of MOXIE.
(Invited) A Review of Electrochemical Methods for Extraction of Oxygen From Regolith
Authors: Hyers Robert
Published: September 2023

The surface of many planetary bodies, including the Moon and Mars, is composed primarily of metal oxides. A number of competing technologies have been proposed to extract oxygen from the dust on the surface. These methods include reduction of the iron- and silicon-containing species by hydrogen or by electrons. The direct electrochemical reduction methods run at different temperatures, from approximately room temperature to over the melting point of iron. Some of these methods produce liquid metal, and others solid metal powders. The latter can optionally extend the electrolysis to recover oxygen from aluminum and titanium species, although at an energetic cost. This talk will review recent progress and current capabilities for these processes.
From Roxy to Mini-Roxy: The Next Step Towards an Efficient Method for Oxygen Extraction from Regolith
Authors: Seidel Achim , Pal Uday , Funke Matthias , Pöhle Georg , Redlich Christian
Published: September 2023

Future exploration missions to the Moon and beyond will be dependent on the use of lunar regolith to produce metals/alloys and oxygen, provided they can be produced very efficiently such that their mass exceeds the mass of any needed consumables or spares to sustain the process. Among the many methods that have been studied so far, molten salt electrolysis with solid oxide membranes appears to be most promising since it meets all of the viability criteria. A specific implementation of this method to lunar applications called ROXY (Regolith to Oxygen and Metals) has been developed and tested, and the design and operations of related demonstration and production facilities have been investigated. As a next step, a miniaturized version of the ROXY cell has been developed, leading to the Mini-ROXY concept and further improvements in terms of process efficiency, and is a new starting point for upscaling the technology.
(Invited) Advanced Organic Electrode Materials for High-Performance and Sustainable Na-Ion Batteries
Authors: Luo Chao
Published: September 2023

Na-ion batteries (NIBs) are promising alternatives to Li-ion batteries (LIBs) due to the low cost, abundance, and high sustainability of sodium resources. However, the high performance of inorganic electrode materials in LIBs does not extend to NIBs because of larger ion size of Na+ than Li+ and more complicated electrochemistry. Therefore, it is vital to search for high-performance electrode materials for NIBs. To this end, organic electrode materials (OEMs) with the advantages of high structural tunability and abundant structural diversity show great promise in developing high-performance NIBs. To achieve advanced OEMs for NIBs, a fundamental understanding of the structure–performance correlation is desired for rational structure design and performance optimization. Tailoring molecular structures of OEMs can enhance their performance in Na-ion batteries, however, the substitution rules and the consequent effect on the specific capacity and working potential remain elusive. Herein, we explored the electrochemical performances and reaction mechanisms of various carboxylate-based anode materials, including halogenated sodium carboxylates, N-doped sodium carboxylates, etc. By examining sodium carboxylates with different functional groups, selective N substitution, and extended conjugation structure, we exploited the correlation between structure and performance to establish substitution rules for high-capacity OEMs. Our results show that substitution position and types of functional groups are essential to create active centers for uptake/removal of Na+ and thermodynamically stabilize organic structures. Furthermore, rational host design and electrolytes modulation were performed to extend the cycle life.

In addition to sodium carboxylate-based anode materials, we also designed and synthesized novel organic cathode materials based on azo and carbonyl groups for NIBs. The electrochemical performance of the organic cathode materials with an extended conjugated structure such as a naphthalene backbone structure is better than that with benzene and biphenyl structures due to faster kinetics and lower solubility in the electrolyte. It unravels the rational design principle of extending π-conjugation aromatic structures in redox-active polymers to enhance the electrochemical performance. To further optimize the organic cathodes, nitrogen-doped or single layer graphene is employed to increase the conductivity and mitigate the dissolution of organic materials in the electrolytes. The resulting organic cathodes deliver high specific capacity, long cycle life, and fast-charging capability. Post-cycling characterizations were employed to study the chemical structure and morphology evolution upon cycling, demonstrating that the active centers (azo and carbonyl groups) in the organic cathode materials can undergo reversible redox reactions with Na+ for sustainable NIBs. Our work provides a valuable guideline for the design principle of high-capacity and stable OEMs for sustainable energy storage.
(Invited) Heterostructure Engineering in Electrode Materials for Sodium Ion Batteries
Authors: Gabriel Eric , Ma Chunrong , Graff Kincaid , Conrado Angel , Hou Dewen , Xiong Claire
Published: September 2023

Sodium-ion batteries (SIBs) have stepped into the spotlight as a promising alternative to lithium-ion batteries (LIBs) for large-scale energy storage systems. However, the stability and performance of sodium ion battery electrode materials are lacking compared to their lithium counterparts as a consequence of the larger size of the Na+ ion compared to Li+. Heterostructure engineering is a promising strategy to overcome these intrinsic limitations toward practical SIBs. In this talk, we review the recent progress in heterostructure engineering of electrode materials and the origin of the phase interface’s influence on the Na+ storage and transport properties. Efficient strategies for the design and fabrication of heterostructures are discussed, with focus on the mechanism of heterostructure formation. The heterostructure’s influence on Na+ storage and transport properties is primarily generated from local distortions of the structure and chemomechanical coupling at the phase interface, which may accelerate ion/electron diffusion, create additional active sites, and bolster the structural stability. Finally, we will discuss the existing challenges, knowledge gaps, and opportunities toward the advancement of heterostructure engineering as a means to develop practical, high-performance sodium ion batteries.
(Invited) Zinc/ Sodium Vanadium Oxide (NaV3O8) Aqueous Electrolyte Batteries: Competing Proton and Zinc Ion Insertion
Authors: Marschilok Amy C. , Takeuchi Esther S. , Takeuchi Kenneth J.
Published: September 2023

Large-scale energy storage systems suitable for pairing with renewable energy generation require low-cost materials and safety. A promising candidate for large scale storage is the aqueous Zn-ion battery (AZIB). Zinc metal is a useful anode for aqueous batteries as it possesses a high theoretical capacity (820 mAh/g), low redox potential (-0.76 V vs SHE), and allows for two electron transfers per Zn2+ (de)insertion.

Sodium vanadium oxides have been investigated as cathode materials for AZIBs as the size of Na+ is larger than Zn2+ facilitating ion diffusion within the lattice. Specifically, sodium vanadium oxide (NaV3O8, NVO) in an anhydrous form and its monohydrate (NaV3O8·H2O) have been identified as candidate materials. Notably, one of the phases that forms during the discharge of these materials within a zinc battery system is zinc hydroxy-sulfate (Zn4(SO4)(OH)6·5H2O (ZHS) and has been attributed to H+ insertion in NVO where the H+ insertion is accompanied by local pH change and precipitation of the ZHS.

This presentation probes the competing zinc ion and proton insertion mechanisms for discharge of NVO. The impact of (dis)charge rate on reduction products formed is determined with quantitative Rietveld refinement analysis. Further, synchrotron based EDXRD providing spatio-temporally resolved data is used to determine phase evolution operando in different locations within thick porous NVO positive electrodes. Determining the reaction progression within thick electrodes while under load is an important aspect of scaling batteries appropriately, where these results can have relevance to development of future sustainable energy storage systems.
Photoactive Electrocatalyst with Staggered p-n Heterojunction for Rechargeable Zn-Air Batteries
Authors: Lee Joong Kee , Ren Ren
Published: September 2023

Rechargeable zinc-air batteries (RZBs) demonstrate significant potential as next-generation batteries as they are non-flammable, resource-abundant, cost-efficient, feasible for ambient air operation, and have remarkable theoretical energy density (1086 Wh kg-1). However, the development of RZBs needs to address many challenges to speed up their commercialization. For example, low round-trip efficiency during cycling is caused by retarded reactivity of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air cathode. An air cathode with deficient electrocatalytic kinetics creates a large voltage gap, especially when the practical charge voltage is > 2.0 V, during the charging and discharging process. Moreover, the cycle life of the RZBs is limited owing to the structural degradation of air cathodes working under high charge voltage. Therefore, it is essential to improve both the round-trip efficiency and structural durability of air cathodes to ensure further development and commercialization of RZBs. For efficient energy generation and storage, photo-enhanced RZBs that combine photochemical and electrochemical energy conversion and storage with the help of solar energy, are a promising research focus. Photo-enhanced RZBs require a photoactive OER/ORR bifunctional cathode that is not merely an electrochemical catalyst but also a photo-active catalyst.

In the present study, we developed a photoactive bifunctional air-electrocatalyst with a staggered p-n heterojunction band gap structure, comprising n-type g-C3N4 and p-type copper-doped ZIF-67 (CuZIF-67) composite, to accelerate sluggish OER/ORR processes via a durable structure and stable long-cycle-life performance for photo-enhanced RZBs. g-C3N4/CuZIF-67 has a suitable band gap, which ensures wide-range light absorption in the UV–Vis–NIR region, and stimulates more electrons to participate in ORR/OER electrocatalytic activity. Besides, it has a staggered bandgap structure and a BEF at the p-n junction of the catalyst, which improves electron–hole pairs separation efficiency, lowers overpotential, promotes ORR/OER electrocatalytic activity, and eventually enhances the efficiency of RZBs (the voltage gap was significantly decreased by 14% with simulated solar light irradiation). Moreover, a high concentration of pyrrolic-N groups in the cathode material, resulting in the excellent electrochemical durability of RZBs during charge/discharge cycles. The photo-enhanced RZB based on the g-C3N4/CuZIF-67 bifunctional catalyst exhibits good round-trip efficiency of 60% (2 mA cm-2) with a significantly decreased voltage gap (from 0.92 to 0.81 V) after 1000 cycles, under simulated solar light irradiation. It can be concluded that staggered p-n heterojunction and pyrrolic nitrogen-rich groups play an important role in efficient and durable photo-enhanced Zn-air batteries.
Hemp-Derived Activated Carbon for the New Generation Zn-Ion Hybrid Supercapacitors
Authors: Tekin Burak , Ilgaz Mehmet Akif , Karaaslan Görkem Dila , Ecevit Buse , Maden Tuğba Bolat , Topcu Yıldıray
Published: September 2023

In this study, Active carbon material was produced from Hemp-based biomasses (they are called Vezir and Narlı) that are Turkey’s first patented plants to be developed by Academic researchers of Ondokuz mayıs University, Agriculture Department, and were first tested as a cathode material for new trend Zn-ion supercapacitors. The stem parts of the hemp plants were used as a precursor in an attempt to obtain the activated carbon, yielding the final product “ activated carbon” by following hydrothermal, pyrolysis and activation processes with KOH. The solid products obtained in each production step (hydrothermal, pyrolysis, activation process) were characterized by advanced structural characterization techniques such as XRD, SEM, TGA, FTIR, BET and TGA. It has been proven by XRD and TGA analyses that the activated carbon material is synthesized without any impurities. While the surface area of the carbon material obtained as a result of pyrolysis was 280 m2/g, the surface area of activated carbon was found to be 1300 m2/g as a result of activation with KOH. For the electrochemical characterization, the activated carbon was tested in the different electrolytes including Zn-ion via Cyclic voltammetry, Scan rate, and galvanostatic charge/discharge measurements. In addition, the plating/stripping process of metallic Zn plate acting as a cathode was investigated through CV measurement. The activated carbon//Zn hybrid supercapacitor exhibited the best performance in 1M Zn(CF3SO3)2 aqueous electrolyte. The optimized supercapacitor delivered a stable capacity of approximately 220 F/g and an energy density of 65 mWh/g without any loss of capacity over 2000 cycles.
A High Voltage Aqueous Zn-Graphite Battery Utilizing "Water-in-Salt" Electrolyte
Authors: Zafar Zahid Ali , Abbas Ghulam , Wahab Abdul , Cervenka Jiri
Published: September 2023

Aqueous zinc-based batteries have the potential to be used for large-scale energy storage because they are inexpensive, safe, and environmentally friendly. However, their energy density is limited because they use low-voltage cathodes and electrolytes. Graphite could be a suitable cathode material for these batteries because it has a high redox potential. However, finding a stable aqueous electrolyte that can handle the high voltage is a major challenge. This study presents a low-cost aqueous zinc-graphite dual-ion battery that uses a Zn(ClO4)2 water-in-salt electrolyte with a wide electrochemical window of 2.80 V. This electrolyte, which contains strong chaotropic ClO4
− anions, allows for the reversible plating and stripping of zinc ions with a low overpotential and a high upper cut-off potential. As a result, the battery is able to deliver a maximum discharge capacity of 45 mA h g−1 at a discharge rate of 100 mA g−1 with a mean discharge voltage of around 1.95 V vs Zn2+/Zn and can be used for over 500 cycles.

References:

A. Z. A. Zafar, et al, Journal of
Materials Chemistry A, 10 (2022) 2064-2074.

A. Zafar, M. Šilhavík, J. Červenka, Patent LU101731
(Invited) Materials Development for Na-Ion Batteries and Insights from Operando Dilatometry and Gas Analysis (DEMS)
Authors: Adelhelm Philipp
Published: September 2023

In the development of sodium ion batteries (SIBs), some classes of materials are showing particular promise. At the same time, there is a need to further improve these materials and, for example, reduce aging processes. In this presentation, the properties of various inorganic electrode materials for SIBs will be discussed. The focus is on carbon materials and carbon/Sn composites (anodes) as well as layered oxides and layered sulfides (cathodes). Operando dilatometry and DEMS (gas analysis) will be used to understand the behavior of the electrodes. By means of dilatometry, information is obtained about the "breathing" of the electrode during ion insertion and removal. Buffer defects caused by nanostructuring or overpotential metal plating can also be detected. DEMS can be used to determine the stability of different electrolyte solutions (ether vs. carbonates) and the cut-off potentials.
(Invited) Enabling Next-Generation High-Performing Sodium Metal Batteries
Authors: Li Weiyang
Published: September 2023

The increasing energy demands of society today have led to pursue alternative energy storage systems that can fulfill rigorous requirements like cost-effectiveness and high storage capacities. Based fundamentally on earth-abundant sodium sources, sodium-based batteries are a promising solution in applications where existing lithium-ion technology remains less economically viable, particularly in large-scale stationary systems such as grid-level storage. Although simply replacing lithium with sodium in current lithium-ion batteries is not a viable solution due to deteriorating electron transfer in conventional intercalation cathodes, sodium is highly attractive when leveraging other battery chemistries due to its unique redox reactions. Sodium metal holds great promise as an attractive anode material for sodium-based batteries owing to its high theoretical specific capacity, low electrochemical potential, low cost and high natural abundance. However, its highly reactive nature with organic electrolyte leads to the formation of unstable solid electrolyte interphase (SEI) and dendritic/mossy sodium growth. In this talk, I will present a series of versatile strategies to realize diverse high-energy sodium metal battery systems through multi-faceted tactical regulations of the electrode-electrolyte interface, electrode structural design, and electrolyte engineering.
(Invited) Harness the Interplay between Local Ordering and Lattice Strain for Boosting Na Ionic Conductivity
Authors: Ouyang Bin , Zeng Yan , Wang Jingyang , Ceder Gerbrand
Published: September 2023

The state-of-art data-driven discovery of novel ionic conductors is mainly driven by the exploration of novel structural frameworks that deliver connected low-barrier diffusion channels for facile ion migration, or the optimization of diffusor/vacancy contents. An orthogonal design strategy is to engineer the key local structures that can be used to reshape the energy landscape. In this presentation, we will demonstrate the influence of two key local structures, e.g., local ordering and lattice strain, on optimizing Na ionic conductivity for solid-state electrolytes. It has been found that orders of magnitude higher ionic conductivity can be accomplished if the local ordering tendency is frustrated, or when the lattice distortion is appropriately optimized. Such a strategy can also induce orders of magnitude higher ionic conductivity without stuffing Na or creating Na vacancies. As instructed by these theoretical discoveries, we will also demonstrate several newly synthesized Na solid-state oxide conductors with ionic conductivity of more than 1 mS/cm.
Molten Sodium Penetration Through Solid-State Nasicon Electrolytes Under High Current
Authors: Hill Ryan Christopher , Peretti Amanda S. , Maraschky Adam M. , Small Leo J. , Spoerke Erik D. , Cheng Yang-Tse
Published: September 2023

High conductivity solid electrolytes, such as NaSICON, are poised to play an increasingly important role in safe, reliable battery-based energy storage, enabling a new class of sodium-based batteries. Increasing demands of both high current densities (≥0.1 A cm-2) and low temperature (<200 °C) operation, coupled with increased discharge times for long duration storage (>12 h), challenge the limitations of solid electrolytes. Here, we explore the penetration of sodium into NaSICON at 0.1 A cm-2 in a symmetric molten sodium cell. Previous studies of β’’-alumina proposed that Poiseuille pressure-driven cracking (Mode I) and low levels of electronic conductivity leading to ion-electron recombination (Mode II) can cause metal accumulation within solid electrolytes, but a comprehensive study at high current density is necessary. To understand and differentiate these modes in NaSICON, this work employs unidirectional galvanostatic testing of Na|NaSICON|Na symmetric cells at 0.1 A cm-2 over 23 1-hour intervals at 110 °C. While galvanostatic testing shows a relatively constant, yet increasingly noisy voltage profile, electrochemical impedance spectroscopy (EIS) between intervals reveals a significant decrease in cell impedance which can be correlated with sodium metal penetration, as observed in scanning electron microscopy (SEM). Significant sodium accumulation from the stripping-side electrode suggests that Mode II failure may be far more prevalent than previously considered. Further, these findings suggest that total charge transported per unit area (mAh cm-2), an important parameter for long duration storage, may be a more critical parameter than current density (mA cm-2) when examining solid electrolyte failure. Together, these results provide a better understanding of the limitations of NaSICON solid electrolytes under high current density and can guide the design of coatings to improve electrode-electrolyte interfaces.
Self-Healing Polymer-Based Electrolyte Induced by Amorphous Three-Dimensional Carbon for High-Performance Solid-State Li Metal Batteries
Authors: Ma Yuhan , Zhang Rui , Wang Liu , He Chunnian , Wong Andrew Barnabas
Published: September 2023

Polyethylene oxide (PEO)-based solid-state electrolyte (SSE) is attractive due to its excellent adhesion with electrodes and good processability. However, PEO is easily penetrated by lithium dendrites because of its soft nature, which will result in inferior battery performance and safety issues. Here, a novel self-healing PEO-based SSE is prepared by incorporating 2 wt% amorphous three-dimensional carbon (3DC). This SSE with low electronic conductivity (in the order of 10-9 S cm-1) which is five orders of magnitude lower than its ionic conductivity (10-4 S cm-1) at 60 oC is suitable to be used in the battery. In addition, the strong adhesion between the 3DC and the PEO matrix as well as the excellent dispersion of 3DC both contribute to the self-healing ability of SSE, which will repair the cracks of SSE formed during battery cycling. Moreover, this SSE shows enhanced ionic and thermal conductivities and mechanical strength, suppressing the formation and growth of lithium dendrites. As a result, this SSE exhibits excellent electrochemical stability, achieving 5000 h of stable cycles in lithium symmetric cell (0.1 mA cm-2, 0.1 mAh cm-2) and 850 long-term stable cycles for the LFP//Li full cell at 1 C.

Figure 1
Interfacial Challenge for Solid-State Lithium Batteries- Liquid Addition
Authors: Yan Shuo , Yim Chae-Ho , Merati Ali , Baranova Elena A. , Abu-Lebdeh Yaser , Weck Arnaud
Published: September 2023

All solid-state lithium batteries with garnet electrolytes (Li7La3Zr2O12, LLZO) are promising energy storage devices that have gained increasing attention due to their huge potential towards non-flammability and higher energy density. However, reported solid-state lithium batteries cannot achieve the projected energy density (> 500 Wh/kg at the cell level) mainly due to insufficient contact and poor compatibility between LLZO and electrodes. The use of liquid electrolytes in small quantities has been suggested as a component in the quasi-solid hybrid electrolytes to address these two issues. However, the working principle of liquid electrolytes added as the interface inside the batteries is not clear yet.

This study added 10L carbonate-based liquid electrolyte between LLZO and LiNi0.6Mn0.6Co0.2O2 (NMC 622) cathode. The assembled Li|LLZO|NMC 622 cell exhibited an initial discharge capacity of 168 mAh g-1 with a capacity retention ratio of ~82 % after 28 cycles. Scanning Transmission X-ray Microscopy revealed the reaction of LE with garnet and NMC 622. More importantly, the LE decomposed and solidified during the cycling process. Decomposed LE participated in the formation of a newly-identified solid-liquid electrolyte interface (SLEI) just after the 1st cycle. Furthermore, the X-ray Absorption Spectroscopy results indicated that the SLEI consisted predominantly of LiF, LaF3, Li2O, and Li2CO3 species.

Overall, this study proved the solidification of liquid electrolytes at the garnet/cathode interface. The formation of SLEI effectively suppressed the degradation of the garnet electrolyte and stabilized the battery cycling performance. More efforts are required to optimize the liquid and establish a more stable SLEI that could expand the cycling life of the batteries.
Cross-Linked Composite Polymer Electrolyte Doped with Li6.4La3Zr1.4Ta0.6O12
Authors: Crockem Ayssia N. , Nicholson Thea M. , Masafwa Kutemwa , Meda Lamartine
Published: September 2023

Interfacial studies were performed on Li-ion conducting solid electrolytes based on cross-linked composite polymer electrolytes (CPEs) with different volume fractions of lithium lanthanum zirconium oxide (LLZTO). Dendrite-free protrusion could be achieved with excellent interfacial stability at current density of 400 mA/cm2 (figure 1)and higher with excellent ionic conductivity of 1.1 × 10−4 S cm−1 at 40 °C. An all-solid-state full cell was fabricated with LiNi0.6Mn0.2Co0.2O2 (NMC) as the cathode and 20 µm of lithium on 15 µm copper anode as well as Li chip (270 µm) for comparison. The cells delivered a capacity of ca. 130 mAh g−1, which proved the effectiveness of the electrolyte. The effect of the different volume fractions on the interfacial properties and the architecture of embedded the solid electrolyte in the cathode will be discussed.

Figure 1
Grain Engineering for High-Performance Garnet-Type Li7La3Zr2O12 Solid Electrolytes
Authors: Wang Yangyang , Thomas Charlotte , Liang Zhiming , Ban Chunmei
Published: September 2023

Garnet-type solid electrolytes based on cubic Li7La3Zr2O12 (LLZO) are promising candidates for the development of Li metal solid-state batteries due to their high ionic conductivity and excellent chemical stability against metallic lithium. Unfortunately, the leakage of electron through the interface and grain boundaries leads to the nucleation of Li dendrite inside solid electrolyte, making it easier for the failure of solid-state Li metal batteries. Here, we introduce a promising fluorination strategy to suppress Li dendrite formation by blocking electron transport through the interface and along the grain boundaries. Fluorination not only decreases the electronic conductivity of garnet pellet but also improves its wettability toward Li metal. As a result, the optimized LLZOge pellet demonstrates an outstanding critical current density of 2.7 mA cm‒2 and ensures ultra-long cyclability over 5000 h at 0.2 mA cm‒2 and over 300 h at 1 mA cm‒2 at room temperature. This work demonstrates the efficacy of the fluorination strategy in increasing the electronic resistance of garnet-type electrolyte for the suppression of Li dendrite growth.

Figure 1
(Invited) Machine Learning for Solid-State Batteries – Progress Versus Hype
Authors: Ong Shyue Ping , Qi Ji , Chen Chi , Chandrappa Manas Likhit Holekevi , Ko Tsz Wai
Published: September 2023

Machine learning in materials science and solid-state batteries are two topics that have captured the imagination of researchers in recent years. Therefore, it is unsurprising that many researchers have attempted to apply the advances in ML to the discovery and study of materials for solid-state batteries. In this talk, I will discuss the importance of going back to fundamentals in the application of ML to materials for solid-state batteries, in particular, the critical solid electrolyte component and its interfaces. I will highlight areas where ML has had a transformative impact on our understanding and discovery of solid electrolytes, and what are some of the remaining challenges that remain to be surmounted.
(Invited) Understanding the Interphasial Phenomena in ALL SOLID State Batteries
Authors: Meng Shirley
Published: September 2023

Compared with the liquid-electrolyte analogues, solid state electrolytes SSEs have drawn increased attention as they promote battery safety, exhibit a wide operational temperature window, and improve energy density by enabling Li metal as anode materials for next-generation lithium-ion batteries. Despite suitable mechanical properties to prevent Li dendrite penetration, relatively wide electrochemical stability windows, comparable ionic conductivities, and intrinsic safety, most SSEs are found to be thermodynamically unstable against Li metal, where SSE decomposition produces a complex interphase, analogous to the SEI formed in liquid electrolyte systems. An ideal passivation layer should consist of ionically conductive but electronically insulating components to prevent the SSE from being further reduced. The past four decades have witnessed intensive research efforts on the chemistry, structure, and morphology of the solid electrolyte interphase (SEI) in Li-metal and Li-ion batteries (LIBs) using liquid or polymer electrolytes, since the SEI is considered to predominantly influence the performance, safety and cycle life of batteries. Study of the buried interfaces in solid state electrolytes has been challenging. Originating from the structural biology field, cryogenic focused ion beam (cryo-FIB) and cryogenic electron microscopy (cryo-EM) have recently been introduced to battery research, and have proven the ability to preserve and probe Li metal for quantitative structural and chemical analysis. All-solid-state batteries (ASSBs) have been promoted as a highly promising energy storage technology due to the prospects of improved safety and a wider operating temperature range compared to their conventional liquid electrolyte-based counterparts. While solid electrolytes with ionic conductivities comparable to liquid electrolytes have been discovered, fabricating solid-state full cells with high areal capacities that can cycle at reasonable current densities remains a principal challenge. To overcome these challenges, a quantitative and in-depth understanding of the phenomena governing ionic and electronic transport limitations within the cathode composite, in addition to mechanical aspects arising from significant volume changes associated with Li metal anodes (including anode-less cell designs) are needed. Such understanding can be obtained from proper electrochemical measurements described herein. In this talk, we will highlight solutions to these existing challenges and several directions for future work are proposed.
Electrochemical Stability of Electrode/Electrolyte Interfaces in Metal Borohydride Solid Electrolytes
Authors: Ko Matthew , Li Yiliang , Mair Sunil , Zhang Duhan , Chiang Yet-Ming
Published: September 2023

Meeting the promise of all-solid-state batteries will require solid electrolytes that have high metal ion conductivity, low electronic conductivity, are electrochemically stable at both low and high potential, and have sufficiently high critical current density to avoid metal dendrite penetration. Metal borohydrides comprise a relatively new class of compounds that is being explored for its potential as a solid electrolyte material. Here, we examine the electrochemical thermodynamic stability of sodium amide borohydride (Na2NH2BH4, or NNB) over the potential range 1.5 to 5 V vs. Na/Na+, using electrodynamic methods, X-ray photoelectron spectroscopy (XPS) characterization of the interfacial reaction products1, and electron microscopy characterization of microstructure. We observe the formation of a CEI layer that passivates the NNB electrolyte up to 5V, while the electrolyte is stable without needing additional passivation down to potentials as low as 1.5V. The onset potentials of the CEI formation reactions agree with those predicted by DFT2 and suggest that the resulting CEI is composed of closo-borohydrates, which are a type of metal borohydride with a cage-like structure that holds promise for high sodium ion conductivities3. XPS measurements of atomic compositions in the CEI layer show the formation of these closo-borohydrates and, coupled with charge transfer calculations, predict that the passivating CEI layer is thin (tens of nm). Impedance spectroscopy is performed to characterize the contribution of the CEI layer to the total cell resistance. Several formation cycling methods are explored to show that with appropriate cycling, the passivating layers contribute <10% to electrolyte resistance in the test cells.

Acknowledgements: This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

References

[1] Tushar Swamy, Xinwei Chen, and Yet-Ming Chiang, “Electrochemical Redox Behavior of Li-ion Conducting Sulfide Solid Electrolytes,” Chem. Mater.,
31[3] 707-713 (2019)

[2] V. Lacivita, Y. Wang, S.H. Bo, G. Ceder. Ab initio investigation of the stability of electrolyte/electrode interfaces in all-solid-state Na batteries. J. Mater. Chem. A, 7., (2019) 7941-8654.

[3] T. J. Udovic, M. Matsuo, A. Unemoto, N. Verdal, V. Stavila, A. V Skripov, and J. J. Rush, “Sodium Superionic Conduction in Na2B12H12,” Chem. Comm.,
50 3750–3752 (2014)