Solid-state Battery Technology Research Articles

Establishing laser cutting of components for sulfide-based solid-state batteries

The demand for safe, power- and energy-dense, low-cost batteries is constantly increasing due to the global shift toward renewable energy sources and the associated need for battery electric vehicles and grid-level energy storage. However, current-generation lithium-ion batteries are struggling to meet the requirements and are reaching their physicochemical limits regarding energy density. Solid-state battery technology promises to improve the current state of the art in electrochemical energy storage and has proven itself in research, although not yet in commercial applications. One of the main challenges in bringing the technology to the market is the limited knowledge and research on the production of solid-state batteries with commercially viable technologies. This study investigates the application of laser cutting technology to improve the cutting process in the production of sulfide-based solid-state batteries. Challenges such as the production atmosphere, handling of the components, and differences compared to conventional battery components are discussed. Using a picosecond laser source, the influence of the pulse frequency, peak fluence, scanning speed, and laser passes was investigated to identify appropriate parameters for cutting sulfide-based composite cathodes. The findings were then successfully applied to the cutting of sulfide-based solid electrolyte separators. An improvement in edge quality compared to mechanical punching is demonstrated, marking a crucial step toward the commercialization of solid-state batteries.

Rational design of hybrid electrolyte for all-solid-state lithium battery based on investigation of lithium-ion transport mechanism

Lithium all-solid-state batteries (ASSBs) are a promising technology for achieving high energy density, long cycle life, and safe rechargeable battery systems. Among these, Li ASSBs using solid polymer electrolytes (SPEs) have gained attention owing to their processability, lightweight nature, flexibility, and favorable electrode contacts. However, SPEs have low ionic conductivity, low Li+ transference number, and lack mechanical strength, limiting cell performance. Therefore, the present study focuses on the development of hybrid polymer electrolytes (HPEs) by incorporating Li1+xAlxTi2-x(PO4)3 (LATP) of Li/Na superionic conductor-type materials into SPEs. The HPEs with LATP 10 wt% exhibited significant improvements with an ionic conductivity of 7.23 × 10−4 S cm−1 at 45 °C and a Li+ transference number of 0.61. Density functional theory calculations supported the enhanced Li-ion migration through the polymer-LATP interface achieved by the optimized LATP content. The addition of LATP particles enhanced the mechanical strength of the electrolytes, effectively suppressing dendrite growth, resulting in a 66.65 % capacity retention after 320 cycles, highlighting the crucial role of high-performance HPEs in advanced ASSBs. By addressing the limitations of SPEs, HPEs offer promising opportunities to unlock the full potential of solid-state battery technologies for various energy storage systems.

Design Principles of Quinone Redox Systems for Advanced Sulfide Solid-State Organic Lithium Metal Batteries.

The emergence of solid-state battery technology presents a potential solution to the dissolution challenges of high-capacity small molecule quinone redox systems. Nonetheless, the successful integration of argyrodite-type Li6PS5Cl, the most promising solid-state electrolyte system,and quinone redox systems remains elusive due to their inherent reactivity. Here, a library of quinone derivatives is selected as model electrode materials to ascertain the critical descriptors governing the (electro)chemical compatibility and subsequently the performances of Li6PS5Cl-based solid-state organic lithium metal batteries (LMBs). Compatibility is attained if the lowest unoccupied molecular orbital level of the quinone derivative is sufficiently higher than the highest occupied molecular orbital level of Li6PS5Cl. The energy difference is demonstrated to be critical in ensuring chemical compatibility during composite electrode preparation and enable high-efficiency operation of solid-state organic LMBs. Considering these findings, a general principle is proposed for the selection of quinone derivatives to be integrated with Li6PS5Cl, and two solid-state organic LMBs, based on 2,5-diamino-1,4-benzoquinone and 2,3,5,6-tetraamino-1,4-benzoquinone, are successfully developed and tested for the first time. Validating critical factors for the design of organic battery electrode materials is expected to pave the way for advancing the development of high-efficiency and long cycle life solid-state organic batteries based on sulfides electrolytes.

Application performance of three common solid-state electrolytes in batteries

Due to the hidden benefits such as the possibilities to make energy density high, safety improved, and lifespan extended, solid-state batteries are a focal point in battery technology research. Current liquid electrolyte-based lithium-ion batteries, despite their maturity, have inherent issues like safety risks and limited energy density. While the advancement in solid-state battery technology can potentially overcome certain challenges, it also encounters its own issues including high contact interface impedance and ion transmission efficiency. For solid-state batteries to supplant traditional lithium-ion batteries in the future, these challenges must be addressed. The research provides an in-depth analysis of the three major types of solid-state electrolytes currently prevalent in the market, including oxide, sulfide, and polymer electrolytes. This is especially true for the electrochemical analysis of batteries after the electrolyte has been used. Each has its unique properties, synthesis methods, and limitations. Oxide electrolytes excel in high-temperature ionic conductivity but underperform at room temperature. Moreover, the synthesis of oxide solid electrolytes requires fine control over temperature and atmosphere, thus demanding high technical expertise. The sulfide category shows promise in room temperature conductivity, albeit with stability issues. Polymer electrolytes, however, are flexible and processable but have generally lower ionic conductivity. To enable large-scale applications, future research needs to focus on improving these electrolytes’ performance and developing cost-effective and efficient synthesis methods. The importance of research into solid-state lithium-ion batteries is tied to their capacity to transform the energy storage sector.

The advances and opportunities of developing solid-state battery technology: Based on the patent Information Relation Matrix

There is a long way for solid-state batteries from the laboratory to large-scale application and commercialization. To overcome a series of challenges, researchers and innovators seek to further understand the processing-structure-properties relationships of solid-state batteries. However, less literature explores the advances and opportunities in solid-state battery technology based on patent analysis. The paper adopts the technology of Natural Language Processing (NLP) to analyze patent documents and reveal the advances and opportunities for developing solid-state battery technology by constructing the patent Information Relation Matrix (IRM). This paper finds innovation activities in developing solid-state batteries have been increasingly active in recent decades, but are uneven across organizations. The electrolyte is a priority area of technology development, and the advances in developing solid-state batteries are perfecting conductivity, reducing interfacial resistance, and improving density and stability. By contrast, the opportunities are to reduce cost, prevent short circuits, and prolong the life cycle. The paper perfects the extant method of constructing IRM and gives insight into the advances and opportunities for developing solid-state batteries. Our findings can help innovators better understand advances in solid-state batteries or opportunities for developing solid-state batteries, from a global perspective.

Advancements and Challenges in Solid-State Battery Technology: An In-Depth Review of Solid Electrolytes and Anode Innovations

The primary goal of this review is to provide a comprehensive overview of the state-of-the-art in solid-state batteries (SSBs), with a focus on recent advancements in solid electrolytes and anodes. The paper begins with a background on the evolution from liquid electrolyte lithium-ion batteries to advanced SSBs, highlighting their enhanced safety and energy density. It addresses the increasing demand for efficient, safe energy storage in applications like electric vehicles and portable electronics. A major part of the paper analyzes solid electrolytes, key to SSB technology. It classifies solid electrolytes as polymer-based, oxide-based, and sulfide-based, discussing their distinct properties and application suitability. The review also covers advancements in anode materials for SSBs, exploring materials like lithium metal, silicon, and intermetallic compounds, focusing on their capacity, durability, and compatibility with solid electrolytes. It addresses challenges in integrating these anode materials, like the interface stability and lithium dendrite growth. This review includes a discussion on the latest analytical techniques, experimental studies, and computational models to understand and improve the anode–solid electrolyte interface. These are crucial for tackling interfacial resistance and ensuring SSBs’ long-term stability and efficiency. Concluding, the paper suggests future research and development directions, highlighting SSBs’ potential in revolutionizing energy storage technologies. This review serves as a vital resource for academics, researchers, and industry professionals in advanced battery technology development. It offers a detailed overview of materials and technologies shaping SSBs’ future, providing insights into current challenges and potential solutions in this rapidly evolving field.

An Industrial Perspective and Intellectual Property Landscape on Solid-State Battery Technology with a Focus on Solid-State Electrolyte Chemistries

This review focuses on the promising technology of solid-state batteries (SSBs) that utilize lithium metal and solid electrolytes. SSBs offer significant advantages in terms of high energy density and enhanced safety. This review categorizes solid electrolytes into four classes: polymer, oxide, hybrid, and sulfide solid electrolytes. Each class has its own unique characteristics and benefits. By exploring these different classes, this review aims to shed light on the diversity of materials and their contributions to the advancement of SSB technology. In order to gain insights into the latest technological developments and identify potential avenues for accelerating the progress of SSBs, this review examines the intellectual property landscape related to solid electrolytes. Thus, this review focuses on the recent SSB technology patent filed by the main companies in this area, chosen based on their contribution and influence in the field of batteries. The analysis of the patent application was performed through the Espacenet database. The number of patents related to SSBs from Toyota, Samsung, and LG is very important; they represent more than 3400 patents, the equivalent of 2/3 of the world’s patent production in the field of SSBs. In addition to focusing on these three famous companies, we also focused on 15 other companies by analyzing a hundred patents. The objective of this review is to provide a comprehensive overview of the strategies employed by various companies in the field of solid-state battery technologies, bridging the gap between applied and academic research. Some of the technologies presented in this review have already been commercialized and, certainly, an acceleration in SSB industrialization will be seen in the years to come.

Room-temperature fabrication of garnet-type solid-electrolyte: Optimizing particle size for high ionic conductivity

Dense and uniform Li6.25Al0.25La3Zr2O12 (Al-doped LLZO) solid-electrolyte film of ∼24 µm thickness is successfully fabricated by room temperature aerosol deposition (AD) method. The process optimization study revealed that careful control of particle size and morphology is one of critical determinants in the development of a compact AD membrane. Notably, our method facilitated an impressive ionic conductivity of approximately 10−5 S cm−1, bypassing the necessity for post-annealing processes, a milestone in itself. However, it is hypothesized that the attained conductivity is somewhat restrained by factors such as smaller grain size and potential surface degradation due to moisture exposure during fabrication, indicating avenues for further research. Looking forward, detailed investigations into the film's microstructure and its impact on transport properties will be a focal point, alongside potential enhancements through post-annealing and particle coating strategies. This research hints at a promising trajectory for the development of high-efficiency solid-state battery technology.

Optimizing ionic transport in argyrodites: a unified view on the role of sulfur/halide distribution and local environments.

Understanding diffusion mechanisms in solid electrolytes is crucial for advancing solid-state battery technologies. This study investigates the role of structural disorder in Li7-x PS6-x Br x argyrodites using ab initio molecular dynamics, focusing on the correlation between key structural descriptors and Li-ion conductivity. Commonly suggested parameters, such as configurational entropy, bromide site occupancy, and bromine content, correlate with Li-ion diffusivity but do not consistently explain conductivity trends. We find that a uniform distribution of bromine and sulfur ions across the 4a and 4d sublattices is critical for achieving high conductivity by facilitating optimal lithium jump activation energies, anion-lithium distances, and charge distribution. Additionally, we introduce the ionic potential as a simple descriptor that predicts argyrodite conductivity by assessing the interaction strength between cations and anions. By analyzing the correlation between ionic potential and conductivity for a range of argyrodite compositions published over the past decade, we demonstrate its broad applicability. Minimizing and equalizing ionic potentials across both sublattices enhances conductivity by reducing the strength of anion-lithium interactions. Our analysis of local environments coordinating Li jumps reveals that balancing high and low-energy pathways is crucial for enabling macroscopic diffusion, supported by investigating percolating pathways. This study highlights the significance of the anionic framework in lithium mobility and informs the design of solid electrolytes for improved energy storage systems.

Insights into the First Multi Transition Element Containing Ruddlesden Popper-Type Cathode for Fluoride Ion Batteries

Fluoride ion batteries (FIBs) have emerged as a recent solid-state battery technology, offering an alternative to traditional battery systems. However, the existing FIBs have encountered challenges related to their poor cycling performance and improved electrodes based on fluoride insertion chemistry are highly sought.Here, we investigate Ruddlesden-Popper type La2Ni0.75Co0.25O4+𝛿 as a promising intercalation-based active cathode material for all-solid-state FIBs. We determine the structural changes of La2Ni0.75Co0.25O4+𝛿 during Fluoride intercalation / de-intercalation by X-ray Diffraction (XRD), electrochemical measurements and X-ray absorption spectroscopy to understand the detailed complex reaction behaviour of the phase, focussing on understanding the changes of Ni, Co oxidation states and coordination environments. Under optimized operating conditions, we obtained a cycle life of 120 cycles at a critical cut-off capacity of 40 mAh/g and over 250 cycles under pressure of 452MPa. The average Coulombic efficiencies ranged from 95% to 99% for the cell running under pressure. Thus, La2Ni0.75Co0.25O4+𝛿 corresponds to the most promising cycling-stable high-energy cathode materials for all-solid-state FIBs with the improved capacity.

Performance Enhancement of Nickel Manganese Cobalt Oxide Cathodic Material for Solid-State Battery Technology by Surface Engineering

Batteries as any other electronic devices are affected by parasitic phenomena including physical processes and chemical reactions occurring within the battery materials as well as their interfaces. The phenomena lead to degradation in performance, impose operation restrictions and potentially make devices unsafe.Solid-state, lithium-metal-based, batteries show promise to meet electric vehicle market requirements, but technical challenges to overcome rapid degradation and cost-effective processing remains. Cathode/electrolyte interfacial side reactions can lead to passivating layer formation, thus increasing cell resistance, unwanted additional overvoltage, and ultimately capacity loss. These phenomena are exacerbated in solid-to-solid contact between solid state electrolytes, active materials, and electronic conductive agents. Therefore, electrode manufacturing design is required to mitigate these issues.Within this work we have evaluated Spray Drying (SD) and Atomic Layer Deposition (ALD) coating processes to engineer the cathode/ electrolyte interface of SSBs, thus improving performance and overall cell cycle life. Cathode materials coating is utilised as an effective strategy to mitigate the degradation of the interface. SD is classically utilised in the food and pharma industries, and it has recently been expanded to include the synthesis/shaping of battery electrode materials as a versatile and robust methodology that can be easily scaled up. ALD is a widely exploited technique in the semiconductor (SC) industry based on self-limiting chemical reactions to deposit stoichiometrically-fixed, defect-free and nanometric-thick materials on surfaces. As such, the application of ALD to coat powders in the battery community is innovative and currently under development.Cathodic materials such as NMC (Nickel Manganese Cobalt Oxides) have been investigated, as the need for improving the capacity retention is strong for high-content (>80%) nickel cathodes. Indeed, ALD utilised to coat NMC powder provides a nanometric thick layer of a dielectric but ionic conductive metal oxide. Optimisation of aluminium oxide shell on a core of polycrystalline high nickel material has been investigated with surface engineering. In parallel, we have been exploring the benefit of SD to create an NMC811 powder showing a decorated structure using two different approaches. Indeed, we have either used preformed metal oxide nanoparticles dispersed in an NMC suspension or synthesised a metal oxide layer on top of the NMC in-situ by a chemical reaction during the spray process.Morphological and chemical characterisation of the products have been crucial to develop the coating processes. Electrochemical Impedance Spectroscopy (EIS) probed the engineered cathode/ electrolyte interface within half- and full-coin cell configuration. Rate performance and long-term cycling evaluation has driven the design of an oxide-based lithium metal solid state battery.Alumina coated powder NMC showed longer capacity retention than raw materials when tested in coin cell batteries. The cells were assembled using thin lithium metal anode, Lithium-Lanthanum Zirconium Oxide (LLZO) electrolyte, and surface-engineered NMC811 supported by aluminium current collector. Key words:Surface Engineering, Coatings, Solid-State Batteries (SSB), Spray Dry, Atomic Layer Deposition (ALD), Preformed Nanoparticles, Nickel Manganese Cobalt Oxide (NMC), NMC811, Lithium Lanthanum Zirconium Oxide (LLZO), Interfaces.

Computationally Predicted New Solid-State Electrolyte (Li5+x PS4+x Cl2-x : 0 ≤ x ≤ 2) and Poly Sulfide Cathodes (Li3+y PS9 or Li5+y PS9Cl2: 0 ≤ y ≤ 9) for High Performance Li Metal Anode Batteries

We used Molecular Dynamics (MD) simulations to study the structures and conductivity of sulfide-based ceramics from the superionic conductor argyrodite family for applications as solid-state electrolyte and cathode materials. These studies combined quantum mechanics (QM) and ReaxFF reactive force field based MD, where the ReaxFF parameters were developed from QM MD.[1]Currently Li10GeP2S12 (LGPS) demonstrates one of the highest Li-ion conductivity for solid state electrolyte, 12 mS/cm at 300K, but it is highly reactive with the Li-metal anode, and it is expensive due to the presence of Ge. We studied the Li ion diffusion mechanism and ionic conductivity of the promising Li6(PS4)SCl solid state electrolyte, predicted to have a conductivity of s = 6 mS/cm, close to experiment (4 mS/cm). We find that Li migration in this electrolyte occurs via conjugated substitutional type diffusion involving rearrangements of three (or more) Li-ions and ~ 3 vacant sites in a 3D matrix of anions that are essentially stationary at 298K (over 20 ns of simulation). We carried out 10 ns of MD simulation to predict a Li-ion conductivity for a single phase Li6(PS4)SCl of 5.9 mS/cm in agreement with solid state NMR measurements of 3.9 mS/cm. Our calculated activation energy of 0.24 eV is within experimentally reported range.[2]We report here the computationally predicted structure of Li5PS4Cl2, a new sulfide Li-superionic conductor with the highest Li-ion conductivity at solid state, which we predict to have Li-ion conductivity of 20 mS/cm at 298 K. We also predicted the directional ionic conductivity and Li-migration barrier in it. This Li5PS4Cl2 has not yet been synthesized and studied experimentally.We also report our results on QM and ReaxFF MD for new polysulfide cathodes, Li3+y PS4+n and Li5+y PS4+nCl2 , both based on Li3PS4. Here, n is the number of excess sulfur atoms in the fully charged polysulfide cathode per formula unit with y=0 and y is the excess Li added to the cathode during discharge processes. We evaluated the performance of these cathode electrolyte systems in terms of interfacial stability and discharge voltages.Li3PS4+5 is a potential cathode for lithium-sulfur batteries. We predicted the structures of Li3PS4+5 finding extra S3 and S7 chains attached to one S atom of each PS4 group. This leads to a density of 2.2 g/cm3. As the cathode is discharged, the lithium atoms fill up all the gaps between S atoms, leading to Li3+9 PS4+5, with 1.7 g/cm3. We studied the dynamics of the discharge as lithium ions from the metal move into the material and react with the S-S bonds to make Li2S. Our predicted discharge curve agrees well with the experimental data (Figure 1).[3]We extended these studies to design a new polysulfide cathode Li5PS4+5Cl2 to be used with our newly predicted Li-superionic conductor electrolytes. The interfacial stability of the Solid electrolyte with S-based cathode and with Li-anode were studied (Figure 2).Our work presents a new strategy for designing materials and processes for solid-state batteries using computational screening and chemical substitution. This demonstrates the potential of using lithium PS4 based superionic conductors with PS4 based cathodes for applications in solid-state batteries. We also addresses some of the key challenges in accelerating solid-state battery development, such as phase stability, transport properties, electrode compatibility etc. This work demonstrates how computational studies can guide new avenues for experimental developments to advance of solid-state battery technology for applications ranging from grid storage to electric vehicles.Acknowledgements:We acknowledge the support from Hong Kong Quantum AI Lab, AIR@InnoHK of Hong Kong Government.

Ordered deficient perovskite La2/3TiO3 films grown via molecular beam epitaxy

As the parent compound of a promising solid electrolyte material Li3xLa2/3−xTiO3, the perovskite La2/3TiO3 has potential for advancing research on Li-intercalated ionic conductors. Epitaxial La2/3TiO3 films have been grown by molecular beam epitaxy using a growth process consisting of deposition and annealing cycles, with in situ monitoring by electron diffraction. X-ray absorption spectroscopy confirms the tetravalent state of Ti in La2/3TiO3, and the as-grown films are insulating. X-ray diffraction reveals the presence of half-order peaks, indicating a doubling of the pseudocubic perovskite unit cell due to the ordering of La vacancies in alternating A-site layers. These results demonstrate that single-phase, vacancy-ordered epitaxial films of La2/3TiO3 can be stabilized with excellent crystalline and electronic properties over wafer-sized areas, making possible Li-ion intercalation studies in films with well-defined domain boundary properties. Such boundaries are known to profoundly influence Li-ion conduction within the material. Understanding the effects of domain boundaries on Li-ion conduction could lead to improvements in solid-state battery technology and pave the way for the development of more efficient and safer energy storage devices.

Multiscale Modeling of Heterogeneous Interfaces in All Solid-State Batteries

Ion transport and degradation at the solid-electorlyte/cathode interfaces dictate the performance of all solid-state batteries. For example, it has been routinely observed that in many superionic oxide conductors, Li-ion transport kinetics are orders of magnitude slower at the interfaces, such as grain boundaries or interfaces with common electrode materials, compared to the bulk phases. Upon electrochemical cycling, interdiffusion and/or electrolyte/cathode decomposition at these interfaces can further deteriorate Li-ion transport kinetics. Therefore, the ability to understand, predict and precisely control ion transport kinetics and the degree of interfacial degradation are critical and would have a transformative impact on the development of solid-state battery technologies for practical applications. Here I will address the need of a multiscale and multiphysics modeling framework to understand Li-ion transport mechanisms at complex interfaces and predict the kinetics of Li-ion transport in solid-electrolyte/cathode composite architectures that are relevant for all solid-state Li batteries. I will also emphasize the importance of using a closely coupled theory-experiment approach to reveal the atomic details of the interfaces and unravel the degradation mechanisms of interfaces and its impact on Li-ion transport. I will use the garnet-type solid-state electrotype and lithium cobalt oxide cathode as an example to demonstrate the predictive power of such a multiscale, multiphysics modeling framework towards establishing the correlations between ion transport and local atomic structure, chemical environment, and mesoscopic microstructure features in the cathode/electrolyte composites.This work was sponsored by the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. An award of computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. This research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357.

Prediction of the emergence of solid-state battery technology in the post-lithium ion battery era: a patent-based approach

ABSTRACT This study aims to predict the commercialization of lithium-based solid-state battery (LSSB) technology and identify the solid electrolyte type that will dominate the market. This study analyzed LSSB patents filed from 2000 to 2020 to determine the current stage of the technology life cycle, and examined the patent quality and competitiveness of three types of solid electrolytes (oxide-, sulfide-, and polymer-based) to identify the most promising. We found that LSSB technology is moving from the emerging to the growth phase, while the oxide-based solid electrolyte is the most promising technology, followed by sulfide- and polymer-based electrolyte technology.

Exploring the potential of material information in patent data: The case of solid-state batteries

The investigation of high-performance materials represents an essential step in the battery industry to develop innovative technologies. While patent analysis could help promote research and development (R&D) by providing insights into innovative activities, the significance of material information contained in patent documents for the advancement of battery technologies has not yet been investigated. This study explored the potential of material information derived from patent data for analyzing the patent landscape by introducing a novel analysis framework. It uses patent claims collected between 2010 and 2021 from the domain of solid-state battery technology to extract and transform material information. This study relies on 1-mode network analysis to construct a material network and a 2-mode network analysis is applied to quantify the extent of the chemical portfolios of assignees. The results indicate that the polymer-based electrolytes are highlighted as the dominant type in the solid-state batteries. A glance at the chemical portfolios of assignees reveals a heterogeneous technology profile, pointing to a highly diversified material knowledge across several industries. The proposed analysis framework is expected to offer a new empirical perspective on the patent landscape in the battery sector by exploiting material information. Broadening the view of material research within the battery sector can support R&D managers and research scientists in the design of improved material search strategies and the selection of appropriate collaborations partners for the respective process.

Solid-state Li-ion batteries with carbon microfiber electrodes via 3D electrospinning

Self-standing carbon fiber electrodes hold promise for solid-state battery technology owing to their networked structures improving interparticle connectivity, robustness contributing to mechanical integrity, and surface sites confining Li dendrites. We here evaluate carbonized 3D electrospun fibers filled with polymer electrolytes as anodes in solid-state lithium half cells. Microscopic analysis of the cells demonstrates the high wettability of carbon fibers with electrolytes, promoting an intimate contact between electrolytes and fibers. Solid-state cells delivered high initial capacities up to ∼300 mAh g−1, although the latter cycles were characterized by gradual capacity fade (∼100 mAh g−1 in the 100th cycle with nearly 100% coulombic efficiency), attributed to the onset of parasitic reactions increasing the cell resistance and polarization. When these were benchmarked against similar cells but with the liquid electrolyte, it was found that Li storage in these fiber electrodes is intermediate between graphite and hard carbon in terms of lithiation voltage (vs Li/Li+), corroborating with the nature of carbon assessed by XRD and Raman analysis. These observations can contribute to further development and optimization of solid-state batteries with 3D electrospun carbon fiber electrodes.

Environmental life cycle assessment of emerging solid-state batteries: A review

Energy storage systems are main drivers in various fields, especially in the context of energy and mobility transition. Battery technologies are one of those options offering good technical performance in multiple stationary and mobile applications. New batteries having potentially high energy density and higher safety with lower cost are in particular ideal candidates for mobility applications. At present especially, lithium-ion batteries are used, but they are facing challenges regarding sustainability and safety issues, which can be quantitatively analyzed with Life Cycle Assessments (LCA). New developments regarding various solid-state batteries (SSBs) are very promising to tackle these challenges, but only very few studies are available on the environmental assessment of SSBs. Prospective LCA methodology is used here to analyze the environmental hotspots over the different life cycle phases for emerging SSBs. This also helps in decisions making at an early stage of development. This review critically analyzes available LCA studies on SSBs focusing on the inventory data, scope of the assessment as well as the life cycle impact assessment results. An effort has been made to compare the different LCA studies considering global warming potential indicator. As a results, the analysis highlights difficulties in comparability due to inconsistencies associated with the data sources, goal and scope, system boundaries and the method of impact assessment etc. To facilitate a consistent comparison, a unification methodology has been proposed to compare different LCAs of SSBs. Overall, the proposed methodology will help to fill the knowledge gap between different existing LCA studies on emerging solid-state battery technologies and provides recommendations for future assessments.

Towards Optimised Cell Design of Thin Film Silicon-Based Solid-State Batteries via Modelling and Experimental Characterisation

To realise the promise of solid-state batteries, negative electrode materials exhibiting large volumetric expansions, such as Li and Si, must be used. These volume changes can cause significant mechanical stresses and strains that affect cell performance and durability, however their role and nature in SSBs are poorly understood. Here, a 2D electro-chemo-mechanical model is constructed and experimentally validated using steady-state, transient and pulsed electrochemical methods. The model geometry is taken as a representative cross-section of a non-porous, thin-film solid-state battery with an amorphous Si (a-Si) negative electrode, lithium phosphorous oxynitride (LiPON) solid electrolyte and LiCoO2 (LCO) positive electrode. A viscoplastic model is used to predict the build-up of strains and plastic deformation of a-Si as a result of (de)lithiation during cycling. A suite of electrochemical tests, including electrochemical impedance spectroscopy, the galvanostatic intermittent titration technique and hybrid pulse power characterisation are carried out to establish key parameters for model validation. The validated model is used to explore the peak interfacial (a-Si∣LiPON) stress and strain as a function of the relative electrode thickness (up to a factor of 4), revealing a peak volumetric expansion from 69% to 104% during cycling at 1C. The validation of this electro-chemo-mechanical model under load and pulsed operating conditions will aid in the cell design and optimisation of solid-state battery technologies.

Ionic Liquid-Supported Interpenetrating Polymer Network Flexible Solid Electrolytes for Lithium-Ion Batteries

In this report, we have prepared the imidazolium-based ionic liquid-incorporated interpenetrating polymer network (IPN) electrolyte membrane containing cellulose triacetate with polyethylene glycol dimethyl acrylate and polyethylene oxide by the UV-induced polymerization method. A facile IPN electrolyte membrane appears to be homogeneous in nature with high mechanical strength, excellent thermal stability, and exhibits optimum ionic conductivity of the order of 2.84 × 10–3 S cm–1. The oxidative stability of the IPN electrolyte membrane is observed up to 5.2 V at room temperature, which is attributed to immobilized ion networks provided by the imidazolium ionic liquid. The IPN electrolyte membrane is galvanostatically cycled having battery configuration Li/IPN EM/LiFePO4, which shows the first discharge capacity of 110 mA h g–1 at 0.05 C with 93.65% Coulombic efficiency at room temperature. The cell shows discharge capacities of about 85, 82, and 76 mA h g–1 at 0.1, 0.2, and 1 C rates, respectively. The ionic liquid-incorporated IPN electrolyte membrane provides a promising system for stabilizing lithium electrodeposition and fabricating high-performance lithium-ion batteries. Finally, IPN electrolyte membranes could be a potential electrolytes for next-generation high-power and safer solid-state battery technology.