bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of High Loading Film Cathode for Thermal Battery
Authors: Ahn Won Jun , Park Mi Seon , Choi Yusong , Ha Sang Hyeon
Published: December 2024

Thermal batteries are the primary reserve batteries operated at high temperature (350-550 ℃). It has been fabricated by pressing powder mixture without polymer binder to maintain the only pellet shaped electrode. The polymer binder commonly used in tape-casting method has been decomposed into organic gases at the operating temperature. The gas has been enclosed in the battery system, and it could be possible to explore. Moreover, the pressing method for the electrode, especially cathode, in not suitable in aspects of time and cost.

This study aims to fabricate film-type cathode with high loading level by using tape-casting method, which not uses the polymer binder. Through this method, it could be fabricated that the cathode with a thickness of 500 um and more. Also, the fabricated film-type cathode shows the high coulombic efficiency compared with pellet-type cathode. Therefore, the results demonstrate that film-type cathode is replaced for existing pellet-type cathode.
Protective Double-Layer Composed of Solid Polymer Electrolyte and Lithiophilic Membrane for Electrodepositing Li Metal
Authors: Choi Hee Joo , Kim Ji-Wan , Bae Hongyeul , Kim Jinhong , Kim Dong-Won
Published: December 2024

Lithium metal batteries using lithium metal as an anode are considered promising energy storage systems due to their high energy density. In this respect, it is essential to manufacture ultra-thin and scalable lithium metal electrodes. Electrodeposition is an efficient method for fabricating thin Li metal electrodes by controlling the current density. However, the dendritic growth and side reactions during the electrodeposition process at high current density remain as obstacles. In this study, we designed a protective double-layer on a current collector composed of solid polymer electrolyte and lithiophilic membrane. The ion-conductive solid polymer electrolyte attached to the current collector suppressed the side reactions on lithium metal and stabilized the surface. The lithiophilic membrane induced uniform Li-ion flux and exhibited high mechanical strength sufficient to substitute a separator. The lithium metal anode was prepared by electrodeposition using a protective double-layer on a current at high current density of 12 mA cm-2, and the deposited lithium electrode was used as an anode when assembling a coin-type lithium metal battery. The lithium metal battery employing deposited lithium metal anode with a protective layer and LiFePO4 cathode was assembled, and its cycling performance was evaluated.
Ester-Based Dual Co-Solvents for Improving Low Temperature Performance of Lithium Iron Phosphate Battery
Authors: Oh Jin-Young , Seok Jinhong , Lim Da-ae , Lim Seong-Jae , Kim Dong-Won
Published: December 2024

Lithium iron phosphate (LFP) batteries are widely expanded in electrical vehicles and energy storage systems (ESS) due to their enhanced safety and low cost. However, their low temperatures performance is a major obstacle for their applications. The sluggish Li+ iondiffusion within electrode at low temperatures suppresses the lithiation or de-lithiation process and ion transport through solid electrolyte interphase (SEI), resulting in poor discharge capacity. To overcome these problems, the electrolytes with improved ionic conductivity and reduced de-solvation energy are being actively investigated. Among them, ester-based solvents have been preferred due to their low viscosity and freezing point. In this study, we applied dual co-solvent systems by combining ester and fluorinated ester that decrease de-solvation energy. Due to the reduction of viscosity, charge transfer and SEI resistance, the LFP cell with dual co-solvent electrolytes exhibited excellent discharge capacity and cycling performance at sub-ambient temperatures. Various analyses such as electrochemical impedance spectroscopy, FT-IR, Raman, NMR, and XPS were used to investigate the electrochemical behavior, solvation structure and chemical composition of the SEI layer. Our study provides new design principles for enhancing the low temperature performance of LFP batteries.
Experimental and Theoretical Study of the Performance of Li-Oxygen Batteries with Multiwall Carbon Nanotube Cathodes
Authors: Andrei Petru , Lobachev Emil
Published: December 2024

Although Li-oxygen batteries with organic electrolyte have a theoretical energy density of 3505 kWh/kg (which is comparable to the energy density of gasoline), in practice only a fraction of this energy density has been demonstrated. Despite this gap, Li-oxygen batteries remain to have a great potential to replace the current energy storage devices in applications requiring light power sources such as portable electronic devices, unmanned aerial vehicles, and renewable energy storage. There is great interest in seeing if Li-oxygen batteries, which have the potential to have a far higher gravimetric energy storage density than any other battery chemistry, can be developed to power electric vehicles (EVs) and allow for driving ranges that are comparable to those of gasoline-powered cars [1]. In this presentation we make a combined experimental and theoretical investigation of the performance of the Li-oxygen batteries for different cathode structures, assembling technique (that can induce different concentrations of seeds available for precipitation and growth in the cathode) and discharge conditions. The theoretical model is based on the traditional drift-diffusion approach, coupled with a simple model that describes the precipitation and growth of lithium peroxide on the carbon nanotubes. The model also predicts that it is optimum to use variable porosity cathodes (with higher porosity on the oxygen side and lower porosity on the separator side) in order to maximize the energy density of these cells, a fact which is also demonstrated using our experimental data. More details about the mathematical approach and a comparison with the experimental data will be presented at the conference.

[1] N. Imanishi and O. Yamamoto, “Perspectives and challenges of rechargeable lithium–air batteries,” Mater. Today Adv., vol. 4, p. 100031, Dec. 2019, doi: 10.1016/j.mtadv.2019.100031.
Enhance Electrochemical Performance of Lithium-Based Batteries Assisted by Vibration
Authors: Jung Taeksoo , Suh Junho , Baek Seunghun , Lee Byeongyong
Published: December 2024

As concerns about global warming increase, the electric vehicle (EV) market grows rapidly. In light of this trend, batteries, which serve as the core of EVs, garner increased attention for enhancing energy density, which is closely related to driving distance. Meanwhile, amidst the rapid transition of power systems from internal combustion engines to batteries, the effect of various environmental factors that may appear in EV operation has remained a missing spot. EVs are regarded as vibrational structures, and batteries are mainly exposed to low-frequency vibration. In this study, we investigated the effect of low-frequency vibration on lithium-ion batteries and lithium-metal batteries, which are the current and next-generation power systems of EVs. We revealed that the implementation of vibration during cycling enhances the discharge capacity of the cells and cycling stability. The increased capacities were maintained at high charging rates, enabling fast charging. This novel combination of vibration and batteries may provide a guideline for exposing batteries to EV-induced vibration.
Discovery of Lithium Solid State Electrolytes through Machine Learned Probability Density Analysis
Authors: Rao Karun K. , Nikolaou Michael , Yao Yan , Wolverton Christopher M. , Grabow Lars Christian
Published: December 2024

Solid state Li-ion conducting electrolytes are a class of materials with appreciable ionic conductivities, but which are still often several of orders of magnitude lower than liquids impeding their commercial adoption in commercial solid-state Li and Li-ion batteries. The major bottleneck to the design of solid electrolytes with high ionic conductivity is the lack of an efficient predictive model of Li-ion diffusivity from either the composition or the crystal structure. Traditional ab initio molecular dynamics (AIMD) simulations have very high accuracy, but are limited by both the number of atoms and timescales they can simulate due to the O(n3) computational cost. Here, we propose using the Li-ion potential energy surface calculated from AIMD to predict ionic conductivity. We show direct correlations (R2= 0.72) between several topological descriptors and both the magnitude of the ionic conductivity and diffusion mechanism across many categories of ionic conductors including oxides, halides, and sulfides. Generating the Li-ion probability density typically requires a full AIMD simulation, however, to accelerate the calculation for new materials, we train a three-dimensional U-net convolutional neural network to predict the Li-ion probability density directly from the pseudo-electron density of the crystal (Figure 1). Using AIMD simulations of fifty known Li-ion conductors as training data, we train a model with 91% test accuracy. Our model is able to efficiently calculate the probability density for new materials including arbitrary compositions, space groups, and site occupations (i.e., disordered structures) which greatly expands the design space over which we can optimize and discover ionic conductors. By screening the ICSD we identify several for new candidate solid state electrolytes and re-identified Li6NBr3. This composition could not be directly simulated using AIMD due to the large unit cell volume, but its ionic conductivity has been experimentally measured as 0.0035 mS/cm at 150°C demonstrating both the accuracy and utility of our model for solid state electrolyte discovery.

Figure 1
Ionic Conductivity Transitions in Sodium Antiperovskite Ionic Conductors
Authors: Zhang Duhan , Li Yiliang
Published: December 2024

Anti-perovskites (AP) materials have recently attracted great interest as a family of solid-state electrolytes with high ionic conduction. Na3OCl is a well-studied prototypical fast ion conducting compound representative of the AP family. Typical solid-state ionic conductors have temperature-dependent ionic conductivity following Arrhenius behavior over a substantial range of temperatures, corresponding to a constant activation energy Ea. In the Na3OCl antiperovskite, there are regimes of Arrhenius behavior separated by broad transitions, all while the structure remains cubic. So far, no clear explanation has been reported for such non-Arrhenius transition of Na3OCl ionic conductivity.

Here, we observe a two-order-of-magnitude increase in its ionic conductivity (from 10-1 to 10 mS/cm) with increasing temperature at 305°C. Temperature-dependent synchrotron X-ray diffraction (SXRD), differential scanning calorimetry (DSC), quasi-elastic neutron scattering (QENS), and impedance spectroscopy, are used to show that the increase in conductivity is correlated with a transition from tetragonal to cubic symmetry associated with a change in octahedral tilt disorder. While previous work has shown that octahedral tilting in APs can create ion migration pathways with lower migration energies than in the regular cubic structure, this is the first instance where such a large increase (100 times) in ionic conductivity due to a change in octahedral tilt disorder has been observed, the octahedral tilt disorder can be exploited as a pathway to increasing the ionic conductivity of antiperovskites and structurally related compounds.

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.
Hidden Electronic Disorder behind Diffusion in Solid-State Electrolytes
Authors: Dhattarwal Harender , Somni Rahul , Remsing Richard C.
Published: December 2024

Solid-state superionic conductors (SSICs) promise significant improvements over liquid electrolytes for energy storage technologies. The advancement and application of SSICs in battery technologies are currently constrained due to an insufficient comprehension of the mechanisms underlying their ion conduction. Conduction in molecular ionic solids is well understood, where conducting ions rapidly diffuse through the rigid lattice. The rotational motion of the lattice often facilitates the rapid ionic diffusion through the “paddle-wheel” motion. This paddle-wheel motion has since become a principle for designing molecular SSICs, but a similar explanation for ion conduction in SSICs composed of monatomic ions is still needed. We predict ion conduction in the SSICs composed of monatomic ions involves 'electronic paddle-wheels,' where the hidden disorder of lone pairs (rotational motion) couple to and facilitate ion diffusion. The electronic paddle-wheel mechanism creates a universal perspective for understanding ion conductivity in both monatomic and molecular SSICs that will create design principles for engineering solid-state electrolytes from the electronic level up to the macroscale. We expect that hidden rotational electronic disorder and the resulting electronic paddle wheels will be an important marker for designing electrolytes through tuning lone pair-mobile ion interactions.
Deconvolved First Cycle Capacity Loss Mechanisms in All-Solid-State Batteries
Authors: Kaeli Emma , Jiang Zhelong , Yang Xiaomian , Choy Emma P.K.L , Liang Nicolas , Wang Sunny , Barks Eddie , Kang Stephen D. , Chueh William C.
Published: December 2024

Deconvolved First Cycle Capacity Loss Mechanisms in All-Solid-State Batteries

All-solid-state batteries (SSBs) fail to compete with their traditional lithium-ion battery (LIB) counterparts due to severe capacity loss in their first cycle. While the key contributors to capacity loss have been identified, it remains unknown the relative contribution of each loss mechanism due to solid electrolyte (SE) redox and worsening kinetics which obscure the measure of capacity. For the chemically abundant sulfur-based composite electrodes in particular, these parallel processes present a formidable challenge to addressing first cycle Coulombic inefficiency.1 Using near-equilibrium electrochemical and X-ray techniques, we demonstrate a full accounting of the sources of capacity loss within our argyrodite SE (Li5PS6Cl) | uncoated Li(Ni0.5Mn0.3Co0.2)O2 (NMC) | carbon composite cathode. By modifying the components of the composite electrode, we differentiate between electrolyte redox at the electronic conductor (current collector + carbon)|SE and NMC|SE interfaces. Using these cell formats we investigate the persistence of electronic conductor interfacial redox across many cycles, as well as the impact of self-discharge on long-term cycling behavior. By modifying the cycling window, we also investigate sluggish discharge kinetics of cathode and oxidation reversibility. Using operando XRD, we compare LIBs and SSBs to track cathode redox throughout cycling, enabling us to differentiate and quantify sources of capacity loss. These findings highlight the need to address overlooked sources of resistance and active material loss in SSBs which are not mitigated by cathode coating solutions.

[1] Janek, J., Zeier, W.G. Challenges in speeding up solid-state battery development. Nat Energy
8, 230–240 (2023).
(Invited) Overview of the Project Solid-Next “Evaluation of All-Solid-State Battery Materials and Foundational Technology Development for Next Generation”
Authors: Fujiwara Yoshiya , Kuzuhara Minoru , Ogihara Wataru , Kawamoto Koji , Miyuki Takuhiro
Published: December 2024

Background:

The rapid expansion of the electric vehicle (EV) market is anticipated due to the increasing adoption of EVs to achieve carbon neutrality by 2050. To gain the initiative in this market, it is crucial to realize and commercialize next-generation all-solid-state lithium-ion batteries (LIBs) that surpass the performance of conventional liquid LIBs.

Project Objectives:

The SOLiD-Next project aims to improve the performance of all-solid-state LIBs and promote the development of battery materials required for their realization. Specifically, we will focus on strengthening the fundamental research and development capability by further advancing material evaluation technologies and expanding evaluation guidelines.

Development of Material Evaluation Platform Technologies

We will develop evaluation platform technologies for next-generation all-solid-state LIB materials, including a standard battery model as a benchmark. By applying this platform, we can accurately evaluate the advantages and disadvantages of new materials and provide detailed feedback to the development process. This will accelerate material development and shorten the time to application.

Elucidation of Phenomena and Mechanisms Unique to All-Solid-State LIBs

We will focus on elucidating the mechanisms unique to all-solid-state LIBs, including particle contact, interfaces, and degradation, especially solid-solid interfaces. Based on the obtained knowledge, we will provide guidelines for electrode, cell, and element technologies and develop advanced analysis and characterization techniques for this purpose.

Development of Electrode and Cell Element Technologies

We will propose next-generation materials and develop electrode and cell element technologies that lead to performance improvements in all-solid-state LIBs by fully utilizing material properties and solving solid-solid interface challenges. The developed technologies will be applied to the development of the standard battery model.

Acknowledgement:

This work is based on the project of ‘Evaluation of All-Solid-State Battery Materials and Foundational Technology Development for Next Generation (SOLiD-Next, JPNP23005)’, commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

Figure 1
Interfacial Effects of the Na Metal State on the Electrochemical Behavior on β"-Alumina Solid Electrolyte
Authors: Qiu Jie , Wang Di , Hwang Jinkwang , Matsumoto Kazuhiko
Published: December 2024

Sodium metal is considered a promising candidate as an anode to maximize the energy density of sodium secondary batteries. The use of β"-alumina solid electrolyte (BASE) is a viable approach to ensure the safe operation of sodium metal batteries.1, 2 Although sodium metal batteries utilizing BASE have gained success at elevated temperatures (e.g. 250 °C), exhibiting stable and efficient cycling performance, even beyond 1000 mA cm−2,3 they are prone to short circuits above certain current densities, which is underscored by a crucial metric referred to the critical current density (CCD). The CCD of BASE typically varies from 0.1 to 10 mA cm−2 at room temperature,1 possibly due to insufficient contact between the rigid surface of BASE and solid sodium metal.

This research focuses on the deposition and dissolution behavior of sodium metal anodes in both liquid and solid states, particularly at slight temperature differences near the melting point of sodium. The CCDs were assessed in a symmetric Na/BASE/Na cell configuration at 90 and 105 °C for solid and liquid sodium (m.p. of sodium 98 °C), respectively. The cell failure was verified by electrochemical impedance spectroscopy after each cycle. Post-test morphological characterizations of the BASE were investigated through scanning electron microscopy. Moreover, rate and cycle performance was assessed using a Na//Na3V2(PO4)3 configuration at two different temperatures. In conclusion, a slight increase in temperature to maintain sodium in the liquid state significantly bolsters the performance of the Na anode, enabling prolonged cycle duration without the dendrite formation causing cell degradation.

References

[1] P. Fertig, K. Skadell, M. Schulz, C. Dirksen, P. Adelhelm and M. Stelter, Batteries Supercaps, 2022, 5, e202100131.

[2] Minnmann, F. Strauss, A. Bielefeld, R. Ruess, P. Adelhelm, S. Burkhardt, S. L. Dreyer, E. Trevisanello, H. Ehrenberg, T. Brezesinski, F. H. Richter, and J. Janek, Adv. Energy Mater., 2022, 12, 2201425.

[3] Landmann, G. Graeber, M. V. F. Heinz, S. Haussener, and C. Battaglia, Mater. Today Energy, 2020, 18, 100515.
In Situ Neutron Diffraction Showing Lithium-Yttrium Chloride Local Structure By Synthesis Method
Authors: Sacci Robert L , Brahmbhatt Teerth , Li Cheng , Guo Liqun , Zheng Jie , Garaga Mounesha N , Greenbaum Steve G , Yao Yan , Nanda Jagjit
Published: December 2024

Lithium halide-based solid electrolytes have high Li+ conductivity and are mostly synthesized through mechanochemical methods.[1] However, Li3InCl6 can be readily synthesized through low-temperature aqueous solution routes by mere dehydration, presumably due to stable InCl6
3- complexation. [2-4] Replacing In for Y results in partial hydrolysis to form YOCl during dehydration because H2O coordinates more strongly to Y3+ cations. We provide insight into the reaction mechanisms involved in synthesizing halide solid electrolytes, highlighting the importance of synthetic and processing conditions to optimize their performance in all-solid-state batteries. We will describe the synthesis process of Li3YCl6 using three different methods and the evolution thereof using in situ neutron diffraction. Our results show that aqueous-based synthesis requires the formation of an ammonium halide complex intermediate. We found that the synthesis method affects changes in local structure within the lattice, which then affect ionic transport and Li+ diffusivity, as determined through diffusion NMR measurements. We ascribe these changes to the correlative transport of Li+. Synthesis affects particle morphology at the macroscale and relates to cycle life when used in a full cell.

This project was supported by the Vehicle Technologies Office (VTO) under the Office of Energy Efficiency and Renewable Energy (EERE) as part of the Battery Materials Research (BMR) program. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.

[1] Park, K.-H.; Kaup, K.; Assoud, A.; Zhang, Q.; Wu, X.; Nazar, L. F. High-Voltage Superionic Halide Solid Electrolytes for All-Solid-State Li-Ion Batteries. ACS Energy Lett. 2020, 5, 2, 533–539.

[2] Li, X.; Liang, J.; Luo, J.; Norouzi Banis, M.; Wang, C.; Li, W.; Deng, S.; Yu, C.; Zhao, F.; Hu, Y.; Sham, T.-K.; Zhang, L.; Zhao, S.; Lu, S.; Huang, H.; Li, R.; Adair, K. R.; Sun, X. Air-Stable Li3InCl6 Electrolyte with High Voltage Compatibility for All-Solid-State Batteries. Energy Environ. Sci. 2019, 12, 2665-2671.

[3] Li, W.; Liang, J.; Li, M.; Adair, K. R.; Li, X.; Hu, Y.; Xiao, Q.; Feng, R.; Li, R.; Zhang, L.; Lu, S.; Huang, H.; Zhao, S.; Sham, T.-K.; Sun, X. Unraveling the Origin of Moisture Stability of Halide Solid- State Electrolytes by In Situ and Operando Synchrotron X-Ray Analytical Techniques. Chem. Mater. 2020,32, 16, 7019–7027.

[4] Sacci, R.L.; Bennett, T.H.; Drews, A.R.; Anandan, V.; Kirkham, M.J.; Daemen, L.L.; Nanda, K. Phase evolution during lithium indium halide superionic conductor dehydration. J. Mater. Chem. A, 2021,9, 990-996.
Integrating All-Polymer Solid State Lithium Metal Batteries with High Areal Loading Cathodes
Authors: Ock Jiyoung , Owensby Kyra D'Yana , Ullman Andrew , Chen Xi Chelsea , Sahore Ritu
Published: December 2024

All solid-state batteries are promising alternative to conventional lithium-ion batteries, because of their high potential in safety, high energy, and power density. However, the induced mechanical stresses from volume changes of electrodes accompanied by electrochemical Li insertion/extraction are a challenge for all solid-state batteries, especially with high loading cathodes (>4 mAh/cm2). In this context, polymer electrolytes are promising candidate due to their flexible features, which may maintain the good contact between the interfaces with sufficient adhesion, upon cycling.

In this study, we present design strategies on integrating polymer electrolytes-based Nickel-rich NMC (LiNixMnyCozO2) composite cathodes in all-polymer solid state lithium metal batteries. We systemically compare three different cell designs focusing on the cathode/electrolyte interface, which is further evaluated by a series of techniques using electrochemical impedance measurement, charge/discharge cycling test, and cryo-microtomed scanning electron microscope. The effect of oxidative stability of the polymer electrolyte on cell performance is discussed as well by comparing two different polymer electrolytes. We present how the polymer electrolyte-integration/cell design protocols link to the cell performance such as capacity, reversibility, and coulombic efficiency.

Acknowledgements

This research was sponsored by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy for the Vehicle Technologies Office’s Advanced Battery Materials Research Program (Simon Thompson, Program Manager). A part of this research was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. The SEM in this work was performed and supported at the Center for Nanophase Materials Sciences in Oak Ridge National Lab, a DOE Office of Science user facility.
Optimal Composition of Co-Doped Li7La3Zr2O12 Soild Electrolyte for Practical Application in Thermal Battery
Authors: Kang Hyungu , Ahn Tae-Young , Roh Heesook , Kang Seung-Ho , Choi Yu Song
Published: December 2024

Lithium thermal batteries have been used in variety of military applications such as missiles, rockets, and emergency escape system as a highly reliable energy storage device. Until recently, to ensure both conductivity and long-term stability, molten salt such as LiF-LiCl–LiBr has been applied as the electrolyte in thermal batteries. However, the occurrence of overflow at high thermal battery working temperature, which is about 500℃, constrains the practical use of molten salt and can cause a leakage phenomenon leading to accidental short circuit within the battery. MgO and SiO2 were discussed as inhibitors to reduce this effect but the problem still remains. Garnet type solid electrolyte Li7La3Zr2O12 (LLZO), especially LLZO doped with metal element, has been widely studied for secondary Li batteries due to its relatively high ionic conductivity, significant electrochemical window, good chemical compatibility with molten lithium, and robust mechanical properties at room temperature. Though, their structural stability outside the operating temperature range of secondary batteries still has not been fully investigated. In this research, we prepared LLZO samples with various doping elements and different composition and compared their high-temperature stability. Techniques such as in situ X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Raman spectroscopy were utilized to confirm the precipitation of Li metal and other impurities at high working temperature of thermal batteries, implying a decomposition reaction had took place. Co-doped LLZO, LLZO samples with two doping elements, were found to have minimal impurities. Experiments uncovering the most suitable composition of co-doped LLZO for practical application were then proceeded subsequently.
Detailed Investigation on LiNbO3-Coated Layer of Different Thicknesses on LiNi0.5Co0.2Mn0.3O2 Cathode Material for All-Solid-State Lithium Batteries
Authors: Bong Willy Shun kai , Kuzuhara Minoru , Kawamoto Koji
Published: December 2024

All-solid-state batteries (ASSBs) are very promising for next-generation energy storage technologies owing to several key advantages including higher power density, better thermal and electrochemical stability, and improved safety for electric vehicles [1, 2]. In this work, bulk-type ASSB cells were prepared with LiNbO3 coatings of different thicknesses, and their electrochemical behaviors at different upper cutoff voltages (upper cutoff potential ≥ 4.40 V) were first systematically compared by using Bulk-type ASSB cells. To eliminate the influence of additives, charge-discharge curves were recorded without conductive carbon or binders in the composite cathodes.

A thicker coating caused three unfavorable electrochemical behaviors in the first three cycles: (1) a higher overpotential, (2) sluggish discharge kinetics, and (3) capacity fading. The measured electronic conductivity decreased drastically with increasing coating thickness, suggesting that this may have caused behaviors (1–3). To overcome this, a carbon additive was used to improve electronic transport in the composite cathode and successfully suppressed the aforementioned behaviors. Our findings indicate that the combination of a thick LiNbO3 coating on NCM523 and carbon additive can achieve synergistic effects to improve both the electrochemical properties and durability of ASSB cells.

To further verify the cycle performance of the NCM523 cathode material with LiNbO3 layers of different thicknesses and uniformity, full-cell ASSBs consisted of a positive electrode and a graphite negative electrode separated by an SE has been fabricated. As a result, the cycle performance was greatly enhanced by increasing the thickness and uniformity of the LiNbO3 coated layer [3]. Our findings further demonstrate that a thick (more than 9 nm) and uniform coated layer (surface without uncoated area) displays outstanding electrochemical performance, especially cycle stability (capacity retention of 85.1% after 300 cycles at 60 ℃), indicating that this strategy is very effective for constructing high-performance NCM cathodes for sulfide-based ASSBs.

【
Acknowledgments
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This study was supported by the SOLiD-NEXT project (JPNP23005) commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

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References
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[1] Y. Kato, S. Hori, T. Saito, K. Suzuki, M. Hirayama, A. Mitsui, M. Yonemura, H. Iba, R. Kanno, Nat. Energy, 1 (2016), 16030.

[2] M. M. Thackeray, C. Wolverton, E. D. Isaacs, Energy Environ. Sci., 5 (2012), 7854−7863.

[3] W. S. K. Bong, A. Shiota, T. Miwa, Y. Morino, S. Kanada and K. Kawamoto, J. Power Sources, 577, 233259 (2023).
Characterization of an Additional LiCl Layer for Enhancing Interfacial Stability between a Solid Electrolyte and Lithium Metal in All-Solid-State Batteries
Authors: Lee Jinuk , Shin Seoyoon , Lee Seok hee
Published: December 2024

Oxide-based solid electrolytes are gaining attention as electrolytes for next-generation all-solid-state batteries (ASSBs) due to their high safety. However, the high interfacial resistance resulting from the solid-solid contact between the solid electrolyte and the electrode surface has been identified as a major cause of performance degradation and remains a critical challenge to be addressed for the practical application of ASSBs. Moreover, the infiltration of lithium dendrites formed during cycling into the solid electrolyte interface causes the performance deterioration, posing a significant impediment to real-world application. To address these challenges, numerous researchers are exploring surface modifications such as the formation of interlayers on solid electrolyte surfaces or the implementation of additional physical treatments. Surface modification through chemical treatment, in particular, is garnering significant interest due to its potential for substantial performance enhancement, low cost, and rapid processing. Among them, the acid treatment has the potential to be applied to practical solid electrolyte surface treatment and is being studied extensively. In this study, interface properties were improved by removing contaminant layers on the solid electrolyte surface and forming a lithium-affinitive layer through acid treatment. We identified the conditions for the formation of a Li2CO3 layer and optimized this layer by reacting it with HCl to remove contaminants. The improved interfacial properties were confirmed by XPS, SEM, Raman analysis and contact angle measurements with lithium metal. To provide an in-depth analysis of the improved interfacial characteristics, we measured the interfacial resistance of the solid electrolyte by using symmetric cell and confirmed the high critical current density and the improved lifetime. In addition, we discussed the performance enhancement mechanism of the lithium-affinitive layer in detail by analyzing the electrical conductivity on the surface and observing lithium dendrite growth using an optical microscope cell.

Figure 1
Synthesis and Densification of Na1+XZr2SixP3-XO12 Nasicon Solid Electrolyte for Solid-State Na Batteries
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Liu I-Chun , Fung Kenneth
Published: December 2024

Solid-state batteries using Na+ ion conductors recently tend to receive much attention because the abundance of Na in earth's crust. When the liquid electrolyte is replaced by ceramic solid electrolytes (SE), the fire incidents observed in conventional rechargeable batteries may be effectively suppressed.

Furthermore, solid-state batteries (SSBs) need to reduce the high interface polarization between electrode and SE. For better Na+ conductivity, Na1+XZr2SiXP3-XO12. With NASICON (Na super ionic conductor) structure is selected for this study. Through solid-state reaction method, it is believed the selection of precursors may be critical for better crystallization and densification of Na1+xZr2SixP3-xO12. For instance, adequate amount of Na2CO3 or Na2SiO3 may be used as the Na source as well as flux for densification. Thus, the objectives of this study is to (1) to investigate the importance of precursors such as Na2CO3 or Na2SiO3 for conduction/densification of NASICON, (2) to search the appropriate temperature for synthesis/crystallization of NASICON, (3) to investigate the factors, such as crystallinity/density, affecting the ionic conductivity. With variation in the stages of processing, the structural, microstructural and electrical properties od decomposed precursors and resultant NASICON will be examined using XRD,SEM and DC/AC impedance measurements.
Electrochemical Responses of Solution-Impregnated Sulfur/Mesoporous Carbon Composites in Liquid Li-S and Solid-State Li-S Batteries
Authors: Karuppaiah Murugesan , Lee Jung Kyoo
Published: December 2024

Lithium sulfur solid-state batteries (Li-S SSBs) have received great attention as next-generation sustainable energy storage devices due to their high energy density, low cost and potential safety. However, start-of-the-art Li SSBs have still faced a few serious of hinders such as distinct high interfacial impedance, insufficient sulfur utilization, lower sulfur mass loading, mismatch triple phase interfaces and also uncertain electrochemical mechanism between liquid and solid-state lithium sulfur batteries. Here, to address these concerns, we employed the encapsulation of sulfur into high conductivemesoporous carbon (MC) by combined solution impregnation and melt-diffusion techniques (IM) to prepare S@MC, and looked into their electrochemical responses in liquid (LiTFSI+LiNO3) and sulfide solid-state (LI6PS5Cl, LPSCl) electrolyte systems. The separately assembled liquid and solid-state Li-S cells exhibited initial discharge capacities of 1438 mAh g-1 and 1411 mAh g-1 at 0.1 C, and capacity retentions of 85.6% (at 0.5 C after 300 cycles) and 48.2% (at 0.5 C after 200 cycles), respectively. In order to enhance the long-term capacity retention of the Li-S SSB prepared by dry mixing of S and LPSCl, we tailored interfaces and introduced ploysulfido-intermediate compounds between S and LPSCl, and thus increasing intimate ionic contact through a weak polar solvent by wet mixing. The solid-state Li-S cells exhibited an initial discharge capacity of 1621 mAh g-1 at 0.1 C with capacity retention of 97.12% (0.1 C initial 5 cycles) and 58.53% (0.5 C after 200 cycles). This work evidently revealed that two step solid-liquid-solid and one step solid-solid charge transfer conversions followed for liquid and sulfide solid state electrolytes, respectively. The solution-impregnated S@MC-2-65%+LPSCl sulfur composite prepared by wet mixing could be potential candidate for high performance Li-S SSBs.
The Dual Role of Thiophosphate Solid Electrolytes as Catholytes and Active Material Precursors in Lithium/Sulfur Solid-State Batteries
Authors: Münch Konrad , Janek Jürgen
Published: December 2024

Lithium/sulfur cell chemistry combines low material cost and high availability of sulfur with high specific energies. However, liquid electrolyte cells are plagued by the parasitic polysulfide shuttle effect between the electrodes, which reduces reversible capacity and efficiency and passivates the negative electrode. Inorganic solid electrolytes (SE) are single-ion conductors and can therefore block the parasitic electrode crosstalk by blocking polysulphide dissolution and transport. In particular, the combination of sulfur battery chemistry with thiophosphate-based SEs is considered obvious due to their high ionic conductivities and their electrochemical stability window corresponding to the usual voltage ranges used in lithium/sulfur battery chemistry.

Lithium/sulfur solid-state batteries (SSLSBs) based on thiophosphate SE are generally reported to have higher capacities, based on the mass of active material, than their liquid counterparts. These can reach up to the theoretical capacity of sulphur (1672 mAh g-1) and even beyond, implying a capacity contribution from the SE and its degradation products. As the degradation products potentially block ionic conduction pathways, this is often considered undesirable. However, other work has reported stable cycling of carbon/SE composites without the addition of additional active material, postulating in situ formation of active material by degradation of the SE.

In this work we show the capacity contribution of the SE by introducing a balance of charge and discharge capacity in SSLSBs. By comparing positive electrode composites with and without additional sulfur as an active material, we show the importance of the storage capacity contribution of the thiophosphate SE in state-of-the-art electrode composites. Using electrochemical and instrumental analysis (XPS, ToF-SIMS), we investigate the formation of degradation products during the first cycles and their reversible redox during cycling. Based on this, we postulate that a controlled amount of degradation may be useful in SSLSBs and that this additional role of SE as a contributor of charge storage capacity may be a design principle for the development of high capacity positive electrode composites.
Phase-Structure-Property Relationships of Halide Coating Materials for Solid Composite Electrodes
Authors: Lee Yeo Kyung , Yun Jonghyeok , Kang Junhee , Lee Jong-Won
Published: December 2024

Lithium-ion batteries (LIBs) have played a pivotal role in advancing energy storage technologies, enabling high-demand applications such as electric vehicles and renewable energy storage systems. Despite their widespread use, LIBs face significant challenges in terms of energy density and intrinsic safety issues. These challenges have spurred interest in all-solid-state batteries (ASSBs), which utilize solid electrolytes (SEs) to offer safe alternatives to conventional liquid electrolyte-based LIBs. Among the various types of SEs explored to date, halide SEs exhibit improved compatibility with high-voltage oxide cathodes, as compared with sulfide-based SEs. Thus, halide SEs may be utilized as cathode coating materials for ASSBs using sulfide SEs with high ionic conductivity. However, the specific material properties that determine the chemical/electrochemical characteristics of halide coatings have not been clearly studied yet.

In this study, we synthesize lithium yttrium chloride (Li3YCl6, LYC) SEs using different methods (solid-state synthesis and ammonium-assisted liquid-phase synthesis) at various heat-treatment temperatures to control phase compositions and crystal structures. These allow us to systematically explore the phase-structure-property relationship of LYC SEs and their roles as coating materials for LiNi0.90Co0.05Mn0.05O2 (NCM). Our experimental findings reveal that the phase, crystal structure and crystallinity of LYC significantly influence the microstructure, ionic conductivity, interfacial compatibility, and thermal stability of LYC-coated NCM (NCM@LYC). The crystal structure and crystallinity of synthesized LYC SEs are explored by Rietveld refinement of X-ray diffraction patterns. Notably, LYC SEs prepared via wet synthesis under optimal heat-treatment conditions exhibit superior Li-ion transport kinetics due to the enhanced crystallinity of phase-pure LYC. This leads to the improved interfacial resistances of NCM@LYC, as evidenced by impedance analyses of NCM composite electrodes. Therefore, the NCM@LYC composite electrodes with the optimized LYC SE show significant improvement in rate capability and cycle lifetimes. This research elucidates the critical role of the synthesis conditions in controlling the properties of halide coating materials and thus in improving the interfacial kinetics and stability of composite cathodes of ASSBs. The insights gained from the phase-structure-property relationships provide valuable guidelines for the development of highly conductive and stable SEs for next-generation batteries.
Discharge Performance of FeF3-Based Cathode for Thermal Battery
Authors: Heesook Roh , Ahn Tae-Young , Choi Yusong , Seung-Ho Kang , Minu Kim , Hae-Won Cheong
Published: December 2024

Thermal battery is used in military application, which can be stored for a long time in an inactive state, and activated by heat. The most commonly used cathode material for thermal battery is FeS2, known for its ease of manufacturing and stable discharge behavior due to low side reactions. However, it has the disadvantage in terms of the energy density as a result of the low discharge voltage. We researched the various cathode materials, and focused on FeF3, which has covalent bonds and thus has a theoretically high discharge voltage. But, the low electrical conductivity of covalent bonds necessitates the addition of a conductive material. It has been reported that CNT significantly improved the conductivity by forming a conductive network among FeF3 particles. In this research, we manufactured the FeF3-based cathode with CNT and salt by powder press molding. The unit cell was constructed with LiCl-LiBr-LiF(with MgO) electrolyte and Li-Si anode and its discharge performance was measured at 500 ℃. We applied a pulse current to the unit cell to compare the internal resistance of the cathode with varying CNT content. The open-circuit voltage of FeF3 was measured at 2.7 V which is higher than 1.9 V of FeS2 making it suitable as a high voltage cathode. But as shown in Figure 1, FeF3 had a higher internal resistance than that of FeS2 with a particularly rapid voltage drop at the begging of discharge. This phenomenon results from a complex effect of side reactions with salt and interfacial reaction with the electrolyte in addition to electrical conductivity. Increasing the CNT content improved this tendency, but it also led to deterioration in a mechanical strength caused by the spring back effect. We investigated the discharge performance of unit cells for the application of FeF3 as a future cathode for thermal battery.

Figure 1
Exploring the Optimal Binder Content of Composite Cathode and Anode for Sulfide-Based All-Solid-State Batteries
Authors: Jo Yong-Han , Lee Young-Jun , Kim Dong-Won
Published: December 2024

All-solid-state batteries (ASSBs) using solid electrolytes (SEs) are promising candidates for next-generation batteries due to their enhanced safety and high energy density compared to conventional lithium-ion batteries using flammable liquid electrolytes. Among various SEs, sulfide-based SEs exhibit high ionic conductivity comparable with liquid electrolytes, and their ductile properties allow them to be processed without high-temperature sintering. Despite these advantages, interfacial contact issues cause the performance degradation of ASSBs. The use of an appropriate polymer binder can maintain good interfacial contact among the electrode components (active material, SE, and conducting carbon) during the repeated cycles. However, using an excessive polymer binder increases the resistance and causes a reduction in energy density because of the decrease of the active material loading in the electrode. Moreover, cathode and anode exhibit different tendencies depending on binder content at the same areal capacity. In this study, we explore the optimal binder content in the composite electrode by evaluating the mechanical and electrochemical properties. Furthermore, we investigate the factors contributing to the disparate behaviors observed between the cathode and anode, and the electrodes that exert a more significant influence on the full cell performance will be ascertained.
Effect of Dopant Concentration in Li7La3Zr2O12(LLZO) on Performance of Thermal Battery
Authors: Ahn Tae-Young , Roh Heesook , Kang Hyungu , Kim Jiyoun , Lee Jongseo , Choi Yusong
Published: December 2024

A thermal battery is a type of reserved battery that operates by melting a mixture of electrolytes to form the battery's functioning components. Due to its ability to function at high temperatures (500°C), it is primarily used as a power source for high-performance equipment, with much higher ionic conductivity than lithium-ion batteries. Furthermore, at room temperature, the molten salt exists in a solid state with little to no ionic conductivity, making it ideal for use in guided weapons that require activation when necessary without self-discharge. However, in order to be used in weapons that operate in a rotating environment such as projectiles, improvements are needed as the molten salt exists in a liquid state at operating high temperatures. Additionally, ceramic binders such as MgO are used to prevent leakage of the molten salt, but this factor increases the resistance of the battery. A LLZO as solid electrolyte, being excellent in thermal stability and remaining solid at the operating temperatures of thermal battery, could improve stability. LLZO is known to exist two kinds of crystal structures, with the cubic crystal structure known to have high ionic conductivity. It has been reported that the cubic crystal structure can be obtained through doping.

A lot of research group has been studied within the temperature range used for lithium ion batteries; therefore, we aimed to select the optimal dopant concentration at high temperatures to improve the discharge performance of thermal batteries. The cubic structure LLZO was synthesized by using Ta, known for its excellent ion conductivity, as a dopant for solid-state transformation. As the amount of Ta dopant increased(Li7−xLa3Zr2−xTaxO12, x = 0.0–0.6), all X-ray diffraction (XRD) results of the obtained LLZO confirmed a cubic crystal structure. The discharge test results confirm that Ta dopant exhibits the best discharge performance when x=0.5, as shown in the figure 1. Although FeS2 is commonly used as a cathode material in thermal batteries, its performance is limited by its low operating voltage. In this study, the performance of solid-state electrolytes was evaluated using FeF3 as a cathode material, known as promising candidates for high voltage. We also present findings to elucidate the performance variation of thermal batteries, which results from the addition of eutectic salts, while utilizing FeF3 as the cathode material and Ta-doped LLZO as the electrolyte.

Figure 1