bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing Electrolyte Stability in Lithium Metal Batteries: A Strategy to Suppress Ionic Liquid Decomposition through Lithium Solvation Power Optimization
Authors: Eom Sewon , Park Minhee , Lee Hongkyung , Lee Wonbo , Lee Hochun
Published: December 2024

Non-flammable and electrochemically stable ionic liquid electrolytes (ILEs) have emerged as promising candidates for thermally stable high-voltage lithium metal batteries (LMBs). To mitigate the high viscosity of ILEs and improve their applicability, research has increasingly focused on incorporating non-solvating co-solvents (NSCs) that dilute ILEs without altering the local Li+ solvation structure. However, NSC with ILEs often undergo extensive reductive decomposition.

Herein, we investigated the reductive behavior of NSC with ILEs and proposed highly stable hybrid electrolyte systems that integrate ILEs with weakly solvating co-solvents (WSCs). Our comparative analysis of various co-solvents, based on their solvation power, elucidates that the interaction between the n-propyl-n-methylpyrrolidinium cation (Pyr13+) and the co-solvents is governed by the co-solvents’ solvation power, which triggers the reductive decomposition of the electrolytes. The incorporation of strongly solvating co-solvents (SSCs) into ILEs, shifts the preferential interaction towards Li+ rather than Pyr13+, thereby minimizing Pyr13+ interaction and reducing reductive decomposition. Furthermore, replacing SSCs with WSCs in ILs results in a reduction in free solvent species, which improves chemical stability and compatibility with Li metal anode. As a result, a novel finding of our study is the effectiveness of an WSC with ILEs system in inhibiting electrolyte decomposition. Specifically, Employing the 1,2-diethoxyethane (DEE) with ILEs system, which incorporates DEE as a representative WSC, we assembled characterized by a high-nickel layered oxide cathode (3.0 mAh cm-2) and thin lithium foil (20 μm). This configuration enables us to achieve an impressive initial battery-level energy density exceeding 380 Wh kg-1 and the capacity retention was 95% for 180 cycles. On the other hand, when TTE, non-solvating co-solvent was added to ILEs, the capacity retention was only 51% for 50 cycles. This research not only advances our understanding of co-solvents with ILE systems but also paves the way for the development of ILs for LMBs with improved performance and stability.

Figure 1
Facile Lithium Densification Kinetics By Hyperporous/Hybrid Conductor for High-Energy-Density Lithium Metal Batteries
Authors: Han Dong-Yeob , Song Gyujin , Park Soojin
Published: December 2024

Lithium metal anode (LMA) emerges as a promising candidate for lithium (Li)-based battery chemistries with high-energy-density. However, inhomogeneous charge distribution from the unbalanced ion/electron transport causes dendritic Li deposition, leading to “dead Li” and parasitic reactions, particularly at high Li utilization ratios (low negative/positive ratios in full cells). Herein, we propose an innovative LMA structural model deploying a hyperporous/hybrid conductive architecture on single-walled carbon nanotube film (HCA/C), fabricated through a nonsolvent induced phase separation process. This design integrates ionic polymers with conductive carbon, offering a substantial improvement over traditional metal current collectors by reducing the weight of LMA and enabling high-energy-density batteries. The HCA/C promotes uniform lithium deposition even under rapid charging (up to 5 mA cm-2) owing to its efficient mixed ion/electron conduction pathways. Thus, the HCA/C demonstrates stable cycling for 200 cycles with a low negative/positive ratio of 1.0 when paired with a LiNi0.8Co0.1Mn0.1O2 cathode (areal capacity of 5.0 mAh cm-2). Furthermore, a stacked pouch-type full cell using HCA/C realizes a high energy density of 344 Wh kg-1
cell/951 Wh L-1
cell based on the total mass of the cell, exceeding previously reported pouch-type full cells. This work paves the way for LMA development in high-energy-density Li metal batteries.
Enhancing Stability of Glass Fiber Separators in Lithium-Ion Batteries through Sol-Gel Hybrid Coatings
Authors: Kang Taewook , Park Young Ji , Kim Jin Ho , Kim Sun Woog , Lee Mi Jai
Published: December 2024

Lithium ion batteries are largely divided into an anode, a cathode, and a separator impregnated with an electrolyte. It is well known that the battery separator is an important element in all batteries, as it physically separates the anode and cathode to prevent the direct flow of electrons, and allows the flow of charge through the movement of ions. Polyolefin-based separators, which are widely used in existing batteries, are vulnerable to rapid environmental changes, drastically reducing battery performance. Additionally, the thermal contraction and expansion that leads to a short circuit significantly reduces the stability of the battery. To overcome stability in such extreme environments, glass fiber separators are emerging as an alternative. To overcome stability in such extreme environments, glass fiber separators are emerging as an alternative. Glass fiber has excellent mechanical properties, electrical insulation, heat resistance, and chemical resistance, so it can drastically improve the stability of the battery. It can also improve electrolyte impregnation by controlling porosity to improve battery performance.

In this study, a sol-gel hybrid coating solution was synthesized and coated on a glass fiber separator to enhance the ionic conductivity and stability. The coating on glass fiber was performed using a dip coating method. The optimization of the hybrid solution and coating conditions led to a reduction in the porosity and enhancement of the flexibility of the glass fiber separators. The adhesion of the coating was evaluated by measuring the hardness of the coating using pencil hardness, and the results showed that the tensile strength of the coated glass fiber separator was improved by about two times compared to before coating. Finally, as a result of evaluating the electrical performance according to the coating, the battery performance was similar at room temperature. On the other hand, it was confirmed that the operating voltage and discharge time at low temperatures were increased by the sol-gel hybrid coating. These results suggest that the coated glass fiber separators are promising candidates for overcoming the stability of battery operation in extreme environments.
Advanced Dual-Layer Protection for Lithium Metal Anodes in Lithium-Sulfur Batteries with Reduced Electrolyte Volume
Authors: Seo Jiyeon , Choi Bokyung , Lee Hongkyung
Published: December 2024

To surpass the energy capacity of current lithium-ion technology, it's vital to develop lithium-sulfur (Li-S) batteries using a minimal amount of electrolyte. However, the quick depletion of electrolyte, driven by reactions at the lithium metal anodes (LMAs), leads to decreased sulfur reaction efficiency and shortened battery lifespan. Addressing this challenge requires a robust protective strategy for LMAs that can withstand the changing dynamics at the interface between the anode and protective layers (PLs). This research highlights the importance of two factors—surface free energy (SFE) and Young’s modulus—in maintaining an adaptable interface between PLs and LMAs, determined through solid mechanics simulations and experiments across three PL configurations. Introducing a dual-layer adaptive protective layer (APL) aims to counter early PL detachment, triggered by lithium pitting. This APL, tailored to adjust to the evolving PL|LMA interface, features a high-SFE polymer inner layer to minimize interfacial energy with the LMA surface, coupled with an elastic outer polymer layer acting as a barrier against electrolyte and lithium polysulfides intrusion. Implementing APL on LMA significantly enhanced the cycling stability of Li-S batteries, effectively doubling their cycle life compared to unprotected LMA configurations, and outperforming single-layer PL setups.
(Invited) Environmentally Benign Solvents Processed Electrically Conductive Polymer Binder for Si Battery
Authors: Liu Gao
Published: December 2024

Green processing of lithium rechargeable battery electrode without NMP solvent and PFAs materials is highly desired for battery manufacturing. The properties of electrode binder play a critical function to achieve green manufacturing process. Electrode binder has been recognized as an important component for the successful engineering of modern lithium-ion rechargeable batteries. Electrode binder provides cohesion among the micron and nano-size electrode particles, adhesion between particles and current collectors, and modulates particles volume changes during charge and discharge. The alloy material-based anode such as Si and Sn, is an attractive candidate for lithium-ion batteries and solid-state battery because it delivers much greater theoretical (e.g. Si at 4200 mAh/g) specific capacity than that of a traditional graphite anode material (∼370 mAh/g). However, the widespread application of silicon materials has remained a significant challenge because of the large volume change during lithium insertion and extraction processes, disrupting the electrode surface, electrode mechanical formation and cell integrity. The instabilities of the alloy materials lead to loss of the electrical contact in the electrode and increased parasitic reactions with electrolyte, causing the battery failure and significantly shorten the battery life. To address those challenges, multifunctional conductive polymers have been re-designed. In the design of conductive polymers, organic functionalities that has strong interaction with environmentally benign solvents are introduced via bottom-up synthetic approaches to achieve green processability. Here, we are reporting a functional electrode binder that enables green processing and has the full functions of conductivity, adhesion and surface protection for the Si materials.
Revealing Morphological and Chemical Changes of Nickel-Rich Oxide Cathodes in Sulfide-Based All-Solid-State Batteries
Authors: Zheng Xueli , Cho Yukio , Yang Guang , Nanda Jagjit
Published: December 2024

Solid-state batteries have emerged as a transformative technology with the potential to revolutionize energy storage systems. Unlike conventional lithium-ion batteries, which rely on liquid electrolytes, solid-state batteries utilize solid electrolytes, offering numerous advantages including enhanced safety, higher energy density, and wider operating temperature ranges. Particularly, sulfide solid electrolytes represent a significant component of solid-state batteries due to their high ionic conductivity. However, key challenges in sulfide solid electrolytes including issues related to interfacial stability and mechanical instability has hindered their commercialization.

Herein, we investigated the capacity loss in LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes when using argyrodite sulfide solid electrolytes, Li6PS5Cl (LPSCl). Specifically, we explored the changes in chemical phase, oxidation state, and morphology of NMC811 cathode and LPSCl solid state electrolyte using synchrotron X-ray absorption spectroscopy and microscopy. Transmission X-ray microscopy images show a clear distinction between charged and charged-discharged NMC811 cathode. Visible microstructural cracking (pulverization) and degradation was observed after discharging the NMC811 cathode. To suppress the cracking formation during battery cycling, we coated NMC811 with lithium niobium oxide (LNO). The LixIn|LPSCl Film|NMC811@LNO full cell exhibited much improved capacity and cycling stability than that of the full cell with the bare NMC811 cathode. Using full-field transmission X-ray microscopy combined with X-ray absorption near edge structure, and sulfur K-edge X-ray absorption spectroscopy, we revealed the interface between NMC811 and argyrodite sulfide solid electrolytes. Our work illuminates the immense potential of solid-state batteries in shaping the future of energy storage, paving the way for safer, more efficient, and sustainable battery technologies.
How Reproducible Is the Performance of All-Solid-State Battery Cells? Α Round Robin Study
Authors: Puls Sebastian , Vargas-Barbosa Nella Marie
Published: December 2024

As the field of all-solid-state battery (ASSB) cells rapidly develops, both from the perspective of new materials as well as processing and cell assembly methods, the necessity for standardized benchmarking protocols that enable interlaboratory comparability increases. At an academic level there are no well-established nor unified protocols for quantifying ASSB cell performance. The latter is in larger part due to the lack of standardized cell setups, processing and cycling parameters among the groups, sometimes limited by accessibility to similar equipment.

To evaluate the interlaboratory reproducibility of ASSB cell performance, we coordinated and report on a Round Robin study that involves 21 experienced groups* across Asia, Europe, and North America. We provided state-of-the-art, commercially-sourced battery materials, namely single crystal LiNi0.6Mn0.2Co0.2O2, (NMC-622) positive electroactive material (CAM), a thiophosphate-based (Li6PS5Cl) solid electrolyte (SE), and indium foil for the preparation of an In/(InLi)
x
alloy negative electrode. All groups were asked to assemble three ASSB cells with the provided materials at specified CAM- and SE-loadings as well as to use the same electrochemical cycling procedure. Moreover, all groups were asked to provide detailed information on their cell assembly protocols and results, including (but not limited to) applied pressures to prepare the battery electrodes, cell dimensions, weighed amounts of materials, and raw electrochemical data.

Massive differences were observed in the specific discharge capacities, which initially ranged from 23.7 to 143.1 mAh⋅g-1, and showed large variabilities in capacity retention (ranging from 0 to 107%). This result is not surprising considering that each group reports its own materials’ processing and cell assembly protocol in which different uniaxial pressures, compression times and cycling (stack) pressures are applied. Although challenging to correlate differences in cycling performance to a single parameter, we identified the initial open circuit voltage, the initial polarization and the cycling pressure as main contributors. We report that 43% of the attempted cells failed. This was mainly due to issues during cell assembly but also due to errors during cycling, suggesting that lab scale ASSB research is challenging and error prone. These problems may have a negative impact on reproducibility if they are not detected during assembly. Considering all the obtained results, we emphasize that triplicate cell data should always be reported by all groups. Due to the large available dataset, we identify important parameters that, if reported, would help improve the interlaboratory reproducibility and comparability of ASSB cell cycling data.

*The total number of researchers involved in this study is 108, representing 26 institutions and will be duly acknowledged in the presentation. Due to space limitations, they are not included in the abstract.
Enhanced Thermal Stability of Charged Cathodes in All-Solid-State Batteries Using Halide Solid Electrolytes
Authors: Jung Sung-Kyun
Published: December 2024

To align with the 2050 carbon neutralization policy and escalate towards net-zero carbon emissions, electric vehicles (EVs) and energy storage systems (ESSs) are increasingly relying on lithium-ion batteries (LIBs). However, LIBs often utilize flammable organic liquid electrolytes, posing significant fire risks. All-solid-state batteries (ASSBs) are expected to address the thermal instability of conventional rechargeable batteries, given nonflammable inorganic solid electrolytes (SEs). Our study introduces an enhanced thermal stability in ASSBs by employing halide solid electrolyte (Li3InCl6, LIC) in charged cathode materials (Li1–xNi0.6Co0.2Mn0.2O2, x ≈ 0.5), significantly mitigating the risks associated with oxygen evolution and thermal decomposition. Unlike sulfide SEs that interact exothermically with cathode materials leading to explosive decompositions, interfacial interplay with the LIC and cathode not only delay decomposition but also capture evolved oxygen through an endothermic reaction, converting it into less reactive metal oxides or oxychlorides (e.g., In2O3, InOCl) phases. Further investigations reveal that other halide SEs such as Li3YCl6 and Li2ZrCl6 also exhibit these oxygen-capturing and heat release-mitigating properties, broadening the potential for developing safer solid-state batteries. These findings underscore the importance of selecting SEs that not only prevent oxygen evolution but also chemically interact with the cathode to reduce the state-of-charge (SOC), thereby enhancing overall battery safety and stability. This study lays foundational criteria for SE design aimed at maximizing thermal safety in ASSBs, thereby supporting the broader adoption of EVs and ESSs in pursuit of global carbon neutrality.
Interfacial Coatings to Enable the High Temperature Co-Sintering of All Ceramic Solid State NMC/LLZO Li Metal Batteries
Authors: Hoft Richard Mariano , Wachsman Eric D
Published: December 2024

Solid-state batteries based on lithium-stuffed oxides ceramics promise to improve the safety and energy density over commercial Li ion batteries. Li7La3Zr2O12 (LLZO) is one of the most promising of these solid electrolytes as it has high ionic conductivity and low reactivity with Li metal. The major challenge of this material is its high interfacial resistance with commonly used cathodes such as LiCoO2 (LCO) and particularly Li2NixMnyCozO2 (NMC) due to the solid-solid nature of the contact and the thermochemical instability of these materials when mixed at high temperatures.

Previous experiments elucidated the nature of the thermochemical instability between LLZO and NMC by exploring various parameters such as sintering atmosphere, Li content of the LLZO, Ni content of the NMC, and processing temperature. This work expands this understanding by introducing an interfacial coating on the NMC to ameliorate the reaction between LLZO and NMC. The coatings explored were lithium metal oxides predicted to be stable with both LLZO and NMC. These interfacial coatings will minimize the interfacial resistance between LLZO and NMC to provide a pathway for producing a solid-state ceramic Li metal battery that can achieve theoretical capacities at commercially applicable charge rates at room temperature.

Preliminary results identified lithium aluminates and lithium silicates as prime interfacial coatings for minimizing the as-assembled interfacial area-specific resistance (ASR) as determined by Electrochemical Impedance Spectroscopy (EIS) of symmetric cells. Furthermore, increasing the Li content of the coatings was shown to further improve the interfacial ASR, confirming computational studies performed by collaborators. These coated NMCs were then fabricated into Li metal full cells using conventional tapecasting, lamination, and sintering processes. These cells were cycled using a constant current and constant voltage cycling procedure with EIS run before and after each charge cycle. These EIS results suggest that delamination caused by the volume change of NMC during electrochemical cycling is the cause for observed capacity fade.
Mixed Conductive Materials to Improve the Conductive Path of All-Solid-State Battery Composite Electrodes
Authors: Jeon Young-Gyu , Lim Chang-Hun , Kim Hyun-Kyung
Published: December 2024

Lithium-ion Batteries (LIBs) function as energy-storage devices in various electronic applications. However, the use of flammable liquid electrolytes raises significant safety concerns, including the risk of fire or explosion. To mitigate these safety issues, all-solid-state batteries (ASSBs) have emerged as a promising alternative as they are composed of solid electrolytes instead of liquid ones. Li7La3Zr2O12 (LLZO) stand out as a highly promising garnet-type solid electrolyte, known for its chemically and electrochemically stable characteristics, making it suitable for ASSBs. However, LLZO suffers from high interfacial resistance, leading to decreased ion conductivity. In particular, the formation of voids during composite electrode fabrication interrupts ion conduction paths, resulting in a significantly increased resistance. Consequently, the high interfacial resistance arising from solid-state contacts can significantly impair the electrochemical performance and hinder practical cell operation. For these reasons, ASSBs typically use an excess of 10 wt.% or more solid electrolytes during electrode manufacturing, leading to a decrease in the active material fraction. Therefore, conducting research on electrode design aimed at optimizing the content of inactive components, such as the use of conductive additives and solid electrolytes, is necessary to improve the performance of ASSBs. In addition, novel approaches are needed to address the above-mentioned issues by reducing the interfacial resistance within composite electrodes containing solid electrolytes and maximizing electrochemical reactions.

This study aims to improve the performance of ASSBs by incorporating carbon nanotubes (CNTs) as a conductive additive with the solid electrolyte LLZO to establish an efficient charge transport pathway and improve interfacial resistance. When using CNT@LLZO as a conductive additive, the internal voids within the electrode are minimized, and an effective Li-ion conduction pathway is formed, resulting in improved electrochemical performance. Further details will be presented in the meeting.
Properties of Li1.3Al0.7Ti1.3(PO4)3 Ceramic Solid Electrolyte Densified by Cold Sintering Process
Authors: Inada Ryoji , Oizumi Kanta , Kurahashi Kaito , Tojo Tomohiro
Published: December 2024

Replacing a flammable organic liquid electrolyte with a non-flammable solid electrolyte is the most promising way to improve the safety of Li-ion batteries. Oxide-based solid electrolytes have the advantages of good chemical stability and ease of handling, but for many of them, the high temperature sintering is required for densification and reduction of grain-boundary resistance for Li-ion conduction. However, co-sintering with electrode active materials at high temperature for fabrication of solid state batteries may cause side reactions and increase the internal resistance.1

Cold sintering (CS) is an attractive process for lowering the densification temperature of various ceramic materials.2
-
7 In this study, we applied CS for the densification of Li-ion conductive Li1.3Al0.7Ti1.3(PO4)3 (LATP) ceramic electrolyte. LATP powder was mixed with proper amount of deionized water or LiOH solution with various concentration as a transient liquid phase (TLP) and densified by CS at 200-250 °C for 0.5 h under uni-axial pressure of 600 MPa. After CS, the relative density of LATP pellet was increased to 85-90 %, and LiOH addition to TLP is effective for increasing the density. Grain size of LATP in the pellet is 0.5-1 µm and nanoparticle precipitation was observed near the grain-boundary area. Similar microstructure is confirmed in previous works.2
-
7 XRD measurements reveal the formation of LiTiOPO4 phase after CS. The amount of LiTiOPO4 phase tends to increase with LiOH concentration. It is thought that this heterogeneous phase precipitate during CS process and plays a role in bonding between LATP particles.

From impedance measurement, we obtained ionic conductivity of 4 × 10-5 S/cm at room temperature in LATP densified at 250 °C by CS with TLP with an optimum LiOH concentration, which is higher than LATP densified by CS with TLP without LiOH (1.7 × 10-5 S/cm) and pressed LATP powder without adding TLP (3.6 × 10-7 S/cm). However, the conductivity of LATP by CS is lower than LATP sintered at 1000 ºC (= 2.3 × 10-4 S/cm). To improve ionic conducting property further, controlling the amount of precipitation phases after CS is necessary.

This work was supported by Grant-in-Aid for Scientific Research (JSPS KAKENHI) Grant Number 22K18793 from the Japan Society for the promotion of Science (JSPS), and Innovative Elemental Technology Research in Green Technologies for Excellence (GteX) Program Grant Number JPMJGX23S7 of the Japan Science and Technology Agency (JST).

References

P. Jiang et al., Energy Technol. 11, 2201288 (2023).

J. Guo et al., Angew. Chem., Int. Ed. 55, 11457-11461 (2016).

J-H. Seo et al., Ceram. Internat. 43, 15370-15374 (2017).

J-H. Seo et al., Jpn. J. Appl. Phys. 60, 037001 (2021).

N. Hamao et al., Materials 14, 4737 (2021).

N. Hamao et al., Chem. Lett. 50, 1784-1786 (2021).

A. Mormeneo-Segarra et al., Ceram. Internat. 49, 36497-36506 (2023).
Scalable Surface Micro-Texturing of LLZO Solid Electrolytes for Battery Applications
Authors: Go Wooseok , Parkinson Dilworth Y. , Oropeza Dayana , Zorba Vassilia , Murali Sriram S. , Doeff Marca M. , Tucker Mike C
Published: December 2024

A challenge for lithium lanthanum zirconate (LLZO)-based solid-state batteries is to increase the critical current density (CCD) to enable high current cycling. A promising strategy is to modify the LLZO surface morphology to provide a larger contact area with Li metal. Examples of such modifying surface morphology include surface patterning through laser cutting [1] and roughening by shot peening [2]. However, these techniques still have challenges in scale-up and application to thin electrolyte layers. Surface patterning using a laser cutter leads to surface contamination requiring post-heat treatment in an inert atmosphere, and shot-peening has a potential risk of mechanical failure caused by impact stress, making it especially difficult to use for thin electrolytes.

Here, we present an easily scalable process to prepare surface-textured thin LLZO electrolytes. The texturing process is a simple pressing of green LLZO tapes between micro-textured substrates. A variety of textures can be produced depending on the type of substrate, and texturing can be on either one side or both sides. For this work, after pressing and sintering, several micro-patterns are formed on thin LLZO (~118 μm thick). The properties of the various samples were characterized to investigate the impact of the surface texturing, and the most promising ones were selected for electrochemical testing in symmetrical lithium cells and full cells. Li symmetric cells using a coarse ridge-textured LLZO exhibit ~2.5 times increased CCD compared to planar non-textured LLZO, and a solid-state full cell shows stable cycling and improved rate performance. We believe this process offers a favorable tradeoff of processing complexity vs. structural optimization to maximize CCD.

[1] Xu R, et al Adv. Mater., e2104009, 33(49), (2021)

[2] Kodama M, et al J. Power Sources, 231556, 537 (2022)
Advantageous Li3PO4 Coating on Conductive Agents for Sulfide-Based All-Solid-State-Batteries
Authors: Jo Younghoon , Moon Janghyuk , Ha Chaeyeon , Chang Hongjun , Kim Young-Jun
Published: December 2024

Sulfide-based all-solid-state-batteries (ASSBs) are garnering attentions as a next-generation battery system due to their high ionic conductivity and the ductility-derived processability. However, it is imperative to address the issue of side reactions between carbon additive-based conductive agents and solid electrolytes. Irreversible reactions of solid electrolytes, stemming from narrow electrochemical stability window, lead to capacity fading of ASSBs. Previous research has explored conductive agents in the form of fibers with a smaller specific surface area or reducing the proportion of conductive agents. Nevertheless, these approaches have not provided a fundamental solution.

Herein, we apply an oxide coating to the surface of carbon nanofiber conductive agents to prevent interfacial side reactions between the electrolyte and the conductive agent. Through computational screening among various oxide-based coating candidates, Li3PO4 is identified as possessing the highest chemical interfacial stability and superior ionic conductivity when interfaced with cathode active materials and solid electrolytes. This approach not only preserves the electronic percolation pathway essential for high-rate capability but also effectively suppress the decomposition of solid electrolytes through a stable ceramic layer. The efficacy of the Li3PO4 coating is demonstrated through enhanced ionic conductivity by up to 150% and improved rate capability and cycle performance in ASSBs, without significant loss of electronic conductivity in the composite cathode. This work introduces a novel concept in conductive agent modification, offering significant advantages in both ionic and electronic conductivity aspects.
4D-STEM of LGPS and NMC Interfaces Reveal Interphase Formation Mechanism
Authors: Paranamana Nikhila C , Werbrouck Andreas , Datta Amit , He Xiaoqing , Young Matthias J.
Published: December 2024

Solid-state lithium-ion batteries (SS-LIBs) are a cutting-edge technology that will enhance safety and energy density compared to traditional LIBs. However, the rapid degradation of SS-LIBs upon charge-discharge cycling is a current barrier to commercialization. This degradation primarily stems from the formation of undesirable compounds at the electrode-electrolyte interfaces, which impede Li+ transport and lead to a reduction in charge capacity. Understanding the reactions occurring at the electrode-electrolyte interface is critical to mitigate this degradation and enhance battery performance. Here, we employ cryogenic four-dimensional STEM (4D-STEM) including energy dispersive spectroscopy (EDS), electron energy loss spectroscopy (EELS), and electron diffraction pair distribution function analysis (ePDF) at ~1 nm spatial resolution to inspect the cathode-electrolyte interfaces in SS-LIBs and study the reaction mechanisms driving interphase formation. For this study we employed Nickel rich LiNi0.6Co0.2Mn0.2O2 (NMC 622) as the cathode electrode material and Li10GeP2S12 (LGPS) as the solid electrolyte. We report a simplified process to measure interphase formation using chemical delithiation of NMC with MoCl5 in ethanol, followed by physical mixing of NMC and LGPS powder before STEM imaging. STEM measurement at the NMC-LGPS interface reveal that anion migration through the interface is a key driver for interphase formation. We also describe the development of a thin-film polyhydroquinone (PHQ) coating formed by oxidative molecular layer deposition (oMLD) as a candidate to encapsulate NMC and mitigate interface formation issues in SS-LIBs. The PHQ coating is expected to act as a selective conductor for cations and electrons, ensuring electrochemical operation of the battery while preventing anion transport. Our latest results showing assembly of SS-LIB cells with and without the oMLD barrier coatings will be discussed to reveal how the oMLD coating influence interface reactions and overall battery performance.

Figure 1
Investigating Electro-Chemo-Mechanical Properties of Conversion Cathodes for Solid-State Batteries
Authors: Alsac Elif Pinar , Nelson Douglas Lars , Yoon Sun Geun , Wang Congcheng , Thomas Talia A. , Eze Udochukwu D , Harris John M , Liu Yuhgene , McDowell Matthew Todd
Published: December 2024

Solid-state batteries (SSBs) could offer higher energy density and improved safety compared to traditional Li-ion batteries. Challenges remain, however, including contact loss/fracture and the effective design of high-conductivity cathode composites. Intercalation-type oxides such as LiNixMnyCo1-x-yO2 (NMC) are widely used in SSB cells. However, these materials have limited capacity and are expensive. Conversion materials such as sulfur, sulfides, and fluorides, on the other hand, show much higher capacity and have been widely investigated for batteries with liquid electrolytes. While their use in conventional Li-ion batteries is challenging due to detrimental interactions with the liquid electrolyte, solid-state batteries (SSBs) offer a potential solution due to improved stability with solid electrolytes. However, conversion cathodes undergo relatively large volume changes during charging and discharging reactions. This volume expansion and contraction is of particular concern for SSBs, since such changes in the all-solid-state environment may lead to interfacial contact loss, cracks within the composite cathode, and degradation of performance.

Here, we investigate the electro-chemo-mechanical evolution of various high-capacity conversion-type solid-state cathode composites (sulfur and other transition metal sulfides). X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) reveal redox reactions at transition metal sites in the composite cathodes, and electron microscopy is correlated to these measurements to determine how cracks evolve within the composite electrodes throughout cycling. The combined electrochemical and spectroscopic measurements reveal that while sulfur has a single conversion step, transition metal sulfides have a more complex, multi-step conversion mechanism. Real-time stack-pressure monitoring is used to provide insight into how stack pressure changes are linked to the diverse reaction pathways during charge and discharge of different conversion cathode materials. We show that there is different pressure evolution behavior for various conversion materials, and the electrode microstructure is also shown to influence stack pressure evolution. Overall, this study gives insight into material evolution and degradation mechanisms, guiding the design of superior cathodes for SSBs.
(Invited) Ionic Liquids As Multifunctional Electrolytes for Sodium Secondary Batteries
Authors: Matsumoto Kazuhiko , Qiu Jie , Wang Di , Liu Huazhen , Zhang Shaoning , Murakami Keisuke , Araya Kousei , Wu Shengan , Hwang Jinkwang
Published: December 2024

To sustain the fast-growing energy demand, high-performance electrolytes and electrode materials are required for secondary batteries. Sodium secondary batteries have emerged as expedient lithium-ion battery alternatives due to the low costs and high abundance of sodium resources. Ionic liquids (ILs) with low vapor pressure and low flammability are fascinating electrolytes for sodium secondary batteries owing to their intrinsic high safety and thermal stability.[1,2] In this talk, multifunctionalities of ionic liquid electrolytes for sodium secondary batteries will be comprehensively presented, especially targeting the performance of a range of negative and positive electrode materials and dual electrolyte system combined with beta-alumina. Intermediate temperature operation is also possible with the aid of thermally stable ionic liquids. Advantages of operation at intermediate temperature will be also discussed based on the results of electrochemical analysis.

References

[1] K. Matsumoto, J. Hwang, S. Kaushik, C.-Y. Chen, R. Hagiwara, Energy Environ. Sci. 12, 3247 (2019).

[2] A. Basile, M. Hilder, F. Makhlooghiazad, C. Pozo-Gonzalo, D. R. MacFarlane, P. C. Howlett, M. Forsyth, Adv. Energy Mater., 8, 1703491 (2018).
Stabilizing Cationic and Anionic Redox in Na-Rich Na2RuO3 Cathode Material Using First Principle Calculations
Authors: Singh Priti , Dixit Mudit
Published: December 2024

In recent years, anionic redox chemistry has garnered significant attention for its application in the development of high-capacity battery materials. However, the incorporation of reversible anionic redox chemistry into cathode materials remains a challenge, primarily due to the release of gaseous molecular oxygen and resulting structural degradation upon cycling. In this study, employing first-principles computational methods and comprehensive analysis, we demonstrate a strategy to adjust the extent of anionic redox in sodium-ion batteries (SIBs) through aliovalent doping. We systematically investigate the electronic structure of a series of metal-doped Na2RuO3 compounds to illustrate this electronic structure tuning approach. Furthermore, we provide a systematic strategy for achieving reversible anionic redox and emphasize that it depends on multiple factors governing the electronic structure of the material, rather than solely relying on the covalent interaction between the transition metal and oxygen. Utilizing the aforementioned strategy, we identify a doped Na-rich material capable of exhibiting reversible cationic and anionic redox. Additionally, we elucidate the reasons for the prevalence of cationic redox over anionic redox in pristine Na2RuO3. Our results not only advance fundamental knowledge but also offer valuable guidance for experimental endeavors aimed at enhancing existing materials and designing innovative cathode materials.

References

Seo, D.-H., et al., Nature Chemistry, 8(7), (2016), 692-697.

Grimaud, A., et al., Nature Materials, 15, (2016), 121-126.

Sathiya, M., et al., Nature Materials, 12(9), (2013), 827-835.

Dixit, M., et al., The Journal of Physical Chemistry C, 121(41), (2017), 22628-22636.
Electrolyte Design to Improve Solid Electrolyte Interphase for Sodium-Ion Batteries
Authors: Das Dhrubajyoti , Puravankara Sreeraj
Published: December 2024

Hard carbon (HC) is a suitable anode for sodium-ion batteries. However, its initial coulombic efficiency is a major drawback resulting in cell energy density loss. This issue can be tackled by designing electrolyte combinations. Increasing the salt concentrations can help the formation of a robust and well-balanced organic-inorganic electrolyte interface layer.1 Anion-derived SEI layer is developed on the electrode surface due to a change of salt concentration to a higher limit.2 The solvation structure of electrolytes also plays a vital role in SEI layer building.3

Commercial hard carbon is studied using the most common solvents, such as ethylene carbonate (EC) and propylene carbonate (PC), in the ratio of 1:1 v/v. NaClO4 and NaFSI salts are used in different concentrations. Our baseline electrolyte is 1M NaClO4 in EC: PC (1:1 v/v) which provides a capacity of 326 mAh g-1 with an ICE value of 63.3% at 0.1C rate (Fig 1a). Changing salt anion from ClO4
- to FSI- does not help improve capacity or coulombic efficiency. However, if we optimized the concentration to 3M, then the capacity would be 356 mAh g-1 with an ICE value of 73% (Fig 1b). This difference in ICE is due to stable anion-derived SEI layer formation. The oral presentation will focus on the effect of salt concentration on the battery performance of Commercial HC and Transition Metal Oxide cathode in half-cell and full-cell configurations in Na-ion batteries.

Reference

Y. Yamada, J. Wang, S. Ko, E. Watanabe, and A. Yamada, Nat. Energy, 4, 269–280 (2019).

J. Patra et al., Energy Storage Mater., 16, 146–154 (2019).

Y. Ugata et al., Phys. Chem. Chem. Phys., 23, 21419–21436 (2021).
(Invited) Challenges and Advances in High-Energy Magnesium Batteries
Authors: Setiawan Dedy , Hwang Jiwon , Choi Jin , Park Yewon , Lee Yeon Woo , Lee Hyungjin , Lee Hochun , Hong Seung-Tae
Published: December 2024

Despite the widespread use of Li-ion batteries, their limited energy density poses a significant challenge. Magnesium (Mg) batteries present a promising alternative due to their higher energy density and lower cost. However, existing Mg battery technologies encounter obstacles, particularly regarding electrode-electrolyte compatibility. The initial Mg battery prototype, employing the Mg/Mo6S8 system, exhibited a mere ~60 Wh/kgcell, significantly lower than Li-ion batteries (~300 Wh/kgcell). Despite efforts over the past two decades to develop new cathodes, electrolytes, and Mg anodes, most reported Mg battery systems have struggled with low energy densities and reproducibility issues.

In this presentation, we highlight recent breakthroughs in Mg batteries, achieving energy densities comparable to Li-ion batteries. Our approach incorporates novel cathode materials developed in our research group, surface-modified Mg anodes, and conventional nonaqueous electrolytes. Through our work, we aim to shed light on the development of advanced Mg battery systems capable of surpassing the energy density limitations of Li-ion batteries while maintaining cost-effectiveness.
Scalable and Cost-Effective Approaches to Rechargeable Zinc Sponge Anodes
Authors: DeBlock Ryan H. , Rolison Debra R. , Long Jeffrey W.
Published: December 2024

Historic metallic zinc (Zn) anodes suffer from catastrophic dendritic growth and limited charge-discharge reversibility in alkaline electrolyte. To combat these issues, the Naval Research Laboratory pioneered a 3D-architected zinc “sponge” anode that distributes the electrochemical reaction thus decreasing local current density and suppressing shape change [1]. Fabrication methods to Zn sponges have evolved from lab-scale protocols with specialized materials to those that are scalable, rapid, and cost-effective. The latest generation of zinc sponge fabrication methods employ common pore-forming agents such as sodium chloride and calcium carbonate combined with chemical sintering and a simplified thermal treatment. These methods are adaptable to various form factors, including plates, cylinders, and discs and can be scaled to hundreds of square centimeters. We evaluate these new Zn sponges in electrochemical configurations including zinc–air, nickel–zinc, and silver–zinc to demonstrate their cycle life and specific power capabilities.

[1] J. F. Parker, C. N. Chervin, E. S. Nelson, D. R. Rolison, and J.W. Long. Energy Environ. Sci. 7 (2014) 1117–1124.
Halogen-Free Electrolytes for Sodium-Ion Batteries
Authors: Flitz Evan Summerwill , Singstock Nicolas , Thomas Charlotte Michele , Garman Kaitlin , Son Seoung-Bum , Ban Chunmei
Published: December 2024

The demand for renewable energy storage requires improved systems based on more affordable, abundant, and efficient chemistries. Sodium-ion batteries (SIBs) meet cost and material availability benchmarks but have yet to realize their full impact due to performance and lifespan limitations owing largely to non-optimized electrolyte chemistry. Current knowledge on interphase chemistries in SIBs is limited and relies far too heavily on that from the lithium community. As a result, fluorine-rich electrolytes are dominant in state-of-the-art SIBs. Here, we show fluorine-free electrolytes for highly reversible SIBs that demonstrate impressive full cell cycling performance. Additionally, using a fluorine-free electrolyte enhances the reversibility of sodium metal's stripping/plating compared to an NaPF6 electrolyte, which enables high-performance anode-free SIBs. Furthermore, This talk will discuss the resulting interfacial compositions that enable improved performance and provide insights for successful interphase engineering for next-generation SIBs.
Microstructure Analysis and Performance Study of Wood Lignin-Derived Carbon Foam Electrode for Sodium-Ion Batteries
Authors: Biswas Diprajit , Yan Qiangu , Cai Zhiyong , Kazyak Eric
Published: December 2024

Carbon foams (CF) offer a promising avenue for advancing energy storage systems due to their unique structure characterized by interconnected open-cell pores and surface-residing carbon nanofibers [1,2]. This structure provides tunability to the porosity, pore structure and size, which makes them ideal for high-energy dense electrodes for energy storage devices. Lignin-derived foams are particularly noteworthy as they utilize an abundant waste stream from paper products, offering a sustainable alternative to fossil-fuel-derived carbons often used in batteries. CFs can serve as electrodes or hosts for energy storage devices based on porosity, pore structure and size, and degree of graphitization, which significantly influences battery capacity, reversibility, and electrochemical reactions [3]. Utilizing natural CF from kraft lignin not only minimizes impacts compared to fossil-fuel-derived carbon sources [4] but also cuts production costs [2], making them an attractive option for large-scale energy storage systems.

In this investigation, we examined lignin-derived CFs with differing porosity and pore structures, carbonized across a temperature range of 800°C to 1300°C. Various characterization techniques corroborated the transition from disordered to ordered carbon structure, escalating the graphitization with the increased carbonization temperatures. Pouch cells are assembled using a standard sodium-based electrolyte. Half-cells demonstrated reversible capacities surpassing 200 mAh/g at C/10, affirming the potential of lignin-derived CF-based Na-ion batteries for large-scale energy storage applications. The performance is studied as a function of CF microstructure, porosity, pore structure and size, particle size, and degree of graphitization for a fundamental understanding of the CF electrode. In conclusion, utilizing sodium and lignin, both abundant and low-cost materials, presents a promising avenue for the energy storage industry on a large scale.

REFERENCES

[1] F. Xu, Y. Gui, S. Zuo, J. Li, S. Wang, Preparation of lignin-based carbon foam monoliths with high strength and developed micrometer-sized cell/nano-sized porous structures using a self-bubbling method, J Anal Appl Pyrolysis 163 (2022).

[2] Q. Yan, R. Arango, J. Li, Z. Cai, Fabrication and characterization of carbon foams using 100% Kraft lignin, Mater Des 201 (2021).

[3] X.Y. Cui, Y.J. Wang, H.D. Wu, X.D. Lin, S. Tang, P. Xu, H.G. Liao, M. Sen Zheng, Q.F. Dong, A Carbon Foam with Sodiophilic Surface for Highly Reversible, Ultra-Long Cycle Sodium Metal Anode, Advanced Science 8 (2021).

[4] S.F. Schneider, C. Bauer, P. Novák, E.J. Berg, A modeling framework to assess specific energy, costs and environmental impacts of Li-ion and Na-ion batteries, Sustain Energy Fuels 3 (2019) 3061–3070.
(Invited) High-Performance Sodium-Ion Battery Using Copper Sulfide Anode and Nasicon-Type Cathode
Authors: Yuk jong Min
Published: December 2024

Recently, the abrupt needs for lithium-ion batteries and the delocalization of lithium and electrode materials are causing battery price increases and instability. As an alternative, sodium-ion batteries are receiving great attention because sodium-ion batteries have relatively cheap raw materials, minerals are distributed around the world, and aluminum can be used as a current collector instead of copper, making the battery relatively inexpensive. In this study, we would like to introduce copper sulfide as a sodium-ion battery anode. Copper sulfide can store a large amount of sodium through alloying and conversion reactions. We also demonstrated that copper sulfide allows the cell to operate stably even at high C-rates because capacity recovery occurs due to the crystal structure of CuS during the sodiation process. In addition, a full cell test was conducted by combining CuS with NVPF/NVP electrode that showed excellent performance. Furthermore, NVPF/NVP has a relatively low capacity compared to other electrode materials, and to solve this problem, doping materials were predicted through machine learning. In addition, in order to protect capacity degradation of CuS at initial cycles, we will introduce presodiation technique and its effects on electrochemical performance and crystal structure of CuS.