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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Stable Cycling with Intimate Contacts Enabled by Crystallinity–Controlled PTFE–Based Solvent–Free Cathodes in All–Solid–State Batteries

All-solid-state batteries (ASSBs) employing Li-metal anodes and inorganic solid electrolytes are attracting great attention due to high safety and energy density for next-generation energy storage devices. However, the volume change of cathode active materials can cause contact loss, resulting in charge carrier isolation, heterogeneous current distribution, and poor electrochemical properties in ASSBs. Here, a simple, yet effective, solvent-free electrode engineering approach with polytetrafluoroethylene (PTFE) as a binder for ASSBs is reported, enabling intimate contact and stable interfaces with the cathode. It is substantiated that the crystallinity of PTFE can be controlled depending on the heat history, and highly crystalline PTFE displays robust mechanical properties. High-nickel LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathode prepared with crystalline PTFE show improved cycle and rate performances in ASSBs. In addition, it is revealed that the intimate contact between cathode particles with a stable cathode electrolyte layer is maintained during cycling by postmortem studies. Furthermore, this simple engineering method can be applied to prepare cathodes with a variety of active materials and solid electrolytes in ASSBs.

25 ENERGY STORAGE↗
DOE OSTI2020

Mechano-Electrochemical Interaction in Solid-State Lithium Batteries

A solid-state lithium (Li) battery primarily consists of Li metal anode, solid electrolyte separator, and cathode. The asymmetric volume changes, originating from ion transport and interfacial Li growth during plating, lead to significant stresses in the layered architecture. In this study, we develop a coupled mechanics-electrochemistry formalism for polymer electrolyte based solid-state batteries, in particular, focusing on the stress effect on electrochemical performance. By means of a coupling coefficient, it is found that stress-assisted ion transport in the electrolyte results in a delayed Sand’s time and increased critical current density of unstable electrodeposition, and consequently, alleviates the propensity of dendrite formation. Stress at the Li metal-electrolyte interface affects the electrochemical reaction kinetics, and the influences from the deviatoric stress and hydrostatic pressure vary with Li plating time. In addition, a low restraint stiffness to the layered structure could elastically buffer the volumetric changes and thus reduce the stress during Li plating. This fundamental study provides guidance for the design of solid-state batteries, aimed at stable electrodeposition and mechanical integrity.

25 ENERGY STORAGE↗
DOE OSTI2025

The Dynamical Role of Optical Phonons and Sublattice Screening in a Solid-State Ion Conductor

Solid-state electrolytes (SSEs) require ionic conductivities that are competitive with liquid electrolytes to realize applications in all-solid-state batteries. Although candidate SSEs have been discovered, the underlying mechanisms enabling superionic conduction (>1 mS cm –1 ) remain elusive. In particular, the role of ultrafast lattice dynamics in mediating ion migration, which involves couplings between ions, phonons, and electrons, is rarely explored experimentally at their corresponding time scales. To investigate the complex contributions of coupled lattice dynamics on ion migration, we modulate the charge density occupations within the crystal framework and then measure the time-resolved change in impedance on picosecond time scales for a candidate SSE, Li 0.5 La 0.5 TiO 3 (LLTO). Upon perturbation, we observe enhanced ion migration at ultrafast time scales. The respective transients match the time scales of optical and acoustic phonon vibrations, suggesting their involvement in ion migration. We further computationally evaluate the effect of a charge transfer from the O 2p to the Ti 3d band on the electronic and physical structure of LLTO. We hypothesize that the charge-transfer excitation distorts the TiO 6 polyhedra by altering the local charge density occupancy of the hopping site at the migration pathway saddle point, thereby causing a reduction in the migration barrier for the Li + hop. We rule out the contribution of photogenerated electron carriers and laser heating. Overall, our investigation introduces a new spectroscopic tool to probe fundamental ion hopping mechanisms transiently at ultrafast time scales, which has previously only been achieved in a time-averaged manner or solely via computational methods.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Li 2.9 Fe 0.9 Zr 0.1 Cl 6 as Redox-Active Catholyte for Solid-State Li-Ion Batteries

Solid electrolytes are one of the key challenges that hinder the commercialization of all-solid-state batteries. Most efforts have been made to advance the development of solid electrolytes as separators, while the development of catholytes, particularly redox-active catholytes, has been less extensively studied. The high loading of catholytes in composite cathodes, while facilitating ionic conduction, drastically decreases the energy density of the battery. Here, we report an alternative strategy to improve the energy density by using Li 2.9 Fe 0.9 Zr 0.1 Cl 6 as a redox-active catholyte. With a composite cathode containing uncoated LiCoO2 and Li 2.9 Fe 0.9 Zr 0.1 Cl 6 , the solid-state cell not only shows excellent rate capability and stable long-term cycling, benefiting from the high ionic conductivity of Li 2.9 Fe 0.9 Zr 0.1 Cl 6 , but also shows a high cathode specific capacity of ~153 mAh·g –1 . This study broadens the chemical space of the materials design for lithium-ion conductors with redox-active elements (e.g., Fe, Ti, V, and Cr), offering new opportunities to reduce the cost and improve the energy density for all-solid-state batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Chemical Bond Covalency in Superionic Halide Solid‐State Electrolytes

Abstract Halide solid‐state electrolytes (SSEs) are promising superionic conductors with high oxidative stability and ionic conductivity, making them attractive for all‐solid‐state lithium‐ion batteries. However, most studies have focused on ion‐stacking structures, overlooking the role of bond characteristics in ionic transport. Here, we investigate bond dynamics and the superionic transition (SIT) in bromide electrolyte, Li 3 InBr 6 , using synchrotron X‐ray techniques and ab initio molecular dynamics (AIMD) simulations. We demonstrate that the SIT in halide SSEs is driven by a thermally induced transition in bonding character (ionic to covalent) rather than a change in crystal phase. AIMD simulations further reveal enhanced Li⁺ diffusion and collective anion motion at elevated temperatures. Expanding our study to Li 3 LnBr 6 (Ln = Gd, Tb, Ho, Tm, and Lu), we confirm the widespread occurrence of SIT in this material class, with Li 3 GdBr 6 exhibiting the highest ionic conductivity (5.2 mS cm −1 at 298 K). More importantly, the ionic‐covalent transition is highly tunable through electrolyte modifications, such as cation/anion substitution and synthesis methods. Our findings provide a new perspective on ionic transport, highlighting the critical role of chemical bond characteristics in halide SSEs.

Chemistry↗
DOE OSTI2024

Decoupling first-cycle capacity loss mechanisms in sulfide solid-state batteries

Solid-state batteries (SSBs) promise more energy-dense storage than liquid electrolyte lithium-ion batteries (LIBs). However, first-cycle capacity loss is higher in SSBs than in LIBs due to interfacial reactions. The chemical evolution of key interfaces in SSBs has been extensively characterized. Electrochemically, however, we lack a versatile strategy for quantifying the reversibility of solid electrolyte (SE) redox for established and next-generation SSB electrolytes. In this work, we perform tailored electrochemical tests and operando X-ray diffraction to disentangle reversible and irreversible sources of capacity loss in positive electrodes composed of Li 6 PS 5 Cl SE, Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 (NMC), and carbon conductive additives. We leverage an atypically low voltage cutoff (2.0 V vs. Li/Li + ) to quantify the reversibility of SE redox. Using slow (5.5 mA g NMC −1 ) cycling paired with >100 h low-voltage holds, our cells achieve a surprising 96.2% first-cycle coulombic efficiency, which is higher than previously reported (mean: 72%, maximum: 91.6% across surveyed literature). We clarify that sluggish NMC relithiation kinetics have been historically mistaken for permanently irreversible capacity loss. In conclusion, through systematic decoupling of loss mechanisms, we uncover the unexpected reversibility of SE redox and isolate the major contributors to capacity loss, outlining a strategy for accurate assessment of next-generation SE materials and interface modifications.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Visualizing Lithium Dendrite Formation within Solid-State Electrolytes

Solid-state electrolyte (SSE) is promising for application in allsolid-state lithium metal batteries because of its reliable safety and longevity. The failure of SSE to suppress dendrite formation of Li metal anodes has been conventionally explained by uneven Li deposition at Li/SSE interfaces and its subsequent dendritic growth. While Li deposition within SSE has been recently proposed as another key cause for SSE failure, little is known regarding the Li growth details inside the SSE itself. In this work, we performed in situ microscopic observation of Li deposition inside the SSE and obtained visualized evidence regarding the dynamic process of Li dendrite formation and growth. Here, Li is seen to directly nucleate and propagate within the SSE, leading to its structural cracking. Such behavior should be caused by the presence of P- and S-based crystalline defects in Li 3 PS 4 SSE, which is consistent with the cryo-transmission electron microscopy observations and theoretical calculations. This observation provides important insights into the growth mechanisms of Li dendrites within a working lithium battery.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Implications of Local Cathode Structure in Solid-State Batteries

Solid-state batteries (SSBs) are promising candidates for energy storage systems—specifically for automotive applications—owing to their higher energy density and supreme safety. SSBs currently must improve area-specific cathode loadings as well as the electro-chemo-mechanical stability at high voltages. Composite cathodes in SSBs are comprised of active material, ion and electronic conductors, binders, and electronic conducting materials. In addition to experimental limitations with engineering thick cathode architectures, low utilization and chemomechanical degradation of the cathodes limit the performance of composite cathodes. Composite cathodes must optimize several parameters simultaneously to achieve high performances that include loading, electrochemically active surface area, mechanical resilience, and porosity. This chapter summarizes the current state-of-the-art applications with regard to composite cathodes for SSBs and provides insights into cathode architectures using geometric packing models. Tailoring ion and electron transport pathways within the electrode while mitigating operational stresses is crucial for achieving energy-dense cathode structres for SSBs.

Dixit, Marm↗
DOE OSTI2024

Visualizing the SEI formation between lithium metal and solid-state electrolyte

The solid electrolyte interphase (SEI) is regarded as the most important factor affecting the durability of lithium-metal anode in all-solid-state batteries (ASSBs). Despite its significance, the nucleation and growth mechanism of SEI is not yet well understood. Here, we elucidate the thermodynamics and kinetics governing SEI formation at the Li|β-Li 3 PS 4 interface at the atomic scale via thermodynamic phase equilibrium analysis and machine-learning-potential-assisted molecular dynamics (MD) simulations. An accurate moment tensor potential using the machine-learning method is developed for a reactive model of Li|β-Li 3 PS 4 . This potential enabled us to perform large-scale MD simulations with the model size expanded to the experimental dimensions (~40 nm) while maintaining the same level of accuracy as density functional theory calculations. The results reveal a four-stage evolution process at the Li|β-Li 3 PS 4 interface, namely (i) fast ion diffusion, (ii) nucleation, (iii) Li 2 S growth, and (iv) stabilization. Notably, we demonstrate that the SEI can be categorized into crystalline and amorphous regions. The simulated SEI thickness, structure, and composition closely match experimental findings, validating the accuracy of the MD simulations. We further disclose the significant impact of ion diffusion kinetic limitations on the phase formation and crystallization of interfacial products. Furthermore, we shed light on the detailed potential energy (PE) distribution of lithium along the direction perpendicular to the interface. Finally, this information is crucial for better understanding interfacial ion mobility.

25 ENERGY STORAGE↗
DOE OSTI2025

Unravelling electro-chemo-mechanical interplay in layered oxide cathode degradation in solid-state batteries

Solid-state batteries (SSBs) hold notable promise for advancing energy storage technologies. However, their commercial viability is limited by the poor cycle stability and complex degradation mechanism. This study underscores the pivotal role of electro-chemo-mechanical interactions in driving the failure of SSBs. Leveraging advanced x-ray imaging and spectroscopy techniques, we analyzed LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathodes from cycled Li x In||Li 6 PS 5 Cl (LPSC)||NMC811 SSBs, uncovering the interplay between microstructure, chemical heterogeneity, mechanical characteristics, and electrochemical performance. Our results show that revealing electro-chemo-mechanical interactions is essential to develop strategies to suppress the degradation of SSBs. Particularly, we revisit a LiNbO 3 (LNO) coating layer to mitigate electrochemical degradation. The LNO@NMC811 cathode retains 116 milliampere-hours per gram after 200 cycles, showing excellent stability, while the uncoated NMC811 cathode keeps degrading over time, with suppressed chemical heterogeneity and mechanical failure. This work highlights the importance of synergizing advanced material design with coating techniques, ensuring uniform lithium flux and improving mechanical properties to achieve stable, high-performance SSBs.

Zheng, Xueli [SLAC National Accelerator Laboratory↗
DOE OSTI2021

Interfacial Defect of Lithium Metal in Solid‐State Batteries

Abstract All‐solid‐state battery with Li metal anode is a promising rechargeable battery technology with high energy density and improved safety. Currently, the application of Li metal anode is plagued by the failure at the interfaces between lithium metal and solid electrolyte (SE). However, little is known about the defects at Li–SE interfaces and their effects on Li cycling, impeding further improvement of Li metal anodes. Herein, by performing large‐scale atomistic modeling of Li metal interfaces with common SEs, we discover that lithium metal forms an interfacial defect layer of nanometer‐thin disordered lithium at the Li–SE interfaces. This interfacial defect Li layer is highly detrimental, leading to interfacial failure such as pore formation and contact loss during Li stripping. By systematically studying and comparing incoherent, coherent, and semi‐coherent Li–SE interfaces, we find that the interface with good lattice coherence has reduced Li defects at the interface and has suppressed interfacial failure during Li cycling. Our finding discovered the critical roles of atomistic lithium defects at interfaces for the interfacial failure of Li metal anode, and motivates future atomistic‐level interfacial engineering for Li metal anode in solid‐state batteries.

Yang, Menghao↗
DOE OSTI2021

Interfacial Defect of Lithium Metal in Solid-State Batteries

All-solid-state battery with Li metal anode is a promising rechargeable battery technology with high energy density and improved safety. Currently, the application of Li metal anode is plagued by the failure at the interfaces between lithium metal and solid electrolyte (SE). However, little is known about the defects at Li–SE interfaces and their effects on Li cycling, impeding further improvement of Li metal anodes. Herein, by performing large-scale atomistic modeling of Li metal interfaces with common SEs, we discover that lithium metal forms an interfacial defect layer of nanometer-thin disordered lithium at the Li–SE interfaces. Further, this interfacial defect Li layer is highly detrimental, leading to interfacial failure such as pore formation and contact loss during Li stripping. By systematically studying and comparing incoherent, coherent, and semi-coherent Li–SE interfaces, we find that the interface with good lattice coherence has reduced Li defects at the interface and has suppressed interfacial failure during Li cycling. Our finding discovered the critical roles of atomistic lithium defects at interfaces for the interfacial failure of Li metal anode, and motivates future atomistic-level interfacial engineering for Li metal anode in solid-state batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Integrated electro- and chemical characterization of sulfide-based solid-state electrolytes

Sulfide solid-state electrolytes (SSEs) represent a critical advancement towards enabling next-generation lithium metal batteries. However, a profound knowledge gap remains in understanding the structure–property relationships inherent to these sulfide SSEs. Electrochemical assessment and spectroscopic tools, such as Raman spectroscopy, offer bench-top ready, non-invasive, powerful avenues for operando and in situ analyses. Despite this potential, the integration of these methodologies, particularly for real-time interrogation, is markedly under-investigated. This review endeavors to catalog the use of diverse electrochemical techniques and spectroscopic tools in elucidating the structural and functional nuances of sulfide SSEs. Through the harmonization of these multifaceted evaluation strategies, our objective is to chart a course towards optimized sulfide SSEs, thereby aiding in the development of informed protocols for a deeper comprehension and understanding of the structure–property relationship and interfacial engineered design of solid-state batteries using sulfide-based SSEs.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Low Melting Temperature Gallium–Indium Liquid Metal Anode for Solid-State Li-Ion Batteries

Solid-state Li-ion batteries are attracting attention for their enhanced safety features, higher energy density, and broader operational temperature range compared to systems based on liquid electrolytes. However, current solid-state Li-ion batteries face performance challenges, such as suboptimal cycling and poor rate capabilities, often due to inadequate interfacial contact between the solid electrolyte and electrodes. To address this issue, we incorporated a gallium–indium (Ga–In) liquid metal as the anode in a solid-state Li-ion battery setup, employing Li 6 PS 5 Cl as the solid electrolyte. Operating at room temperature, this configuration achieved an initial capacity of 389 mAh g –1 and maintained 88% of this capacity after 30 cycles at a 0.05 C rate. It also demonstrated a capacity retention of 66% after 500 cycles at a 0.5 C rate. In comparison to solid anode materials, such as tin, the Ga–In liquid metal exhibited superior cycling stability and rate capacity, which is due to the self-healing and fluid properties of the alloy that ensure stable interfacial contact with solid electrolytes. In situ X-ray diffraction (XRD) and ex situ scanning electron microscope (SEM) analyses revealed that indium does not directly participate in the lithiation/delithiation process. Instead, it helps maintain the alloy’s low melting point, facilitating its return to a liquid state after delithiation. In a comparative analysis of stack pressure during cycling in cells utilizing Ga–In liquid metal and tin, the Ga–In liquid metal cell demonstrated an ability to buffer pressure increases associated with deformation. In conclusion, these findings suggest a promising approach for enhancing solid-state batteries by integrating liquid metal anodes, which improve interfacial contact and stability.

Alloys↗
DOE OSTI2026

Frequency reproducibility of solid-state thorium-229 nuclear clocks

Solid-state thorium-229 ( 229 Th) nuclear clocks are set to provide new opportunities for precision metrology and fundamental physics. Taking advantage of inherent low sensitivity of a nuclear transition to its environment, orders of magnitude more emitters can be hosted in a solid-state crystal compared with current optical lattice atomic clocks. Furthermore, solid-state systems needing only simple thermal control are key to the development of field-deployable compact clocks. Here we explore and characterize the frequency reproducibility of the 229 Th:CaF 2 nuclear clock transition, a key performance metric for all clocks. We measure the transition linewidth and centre frequency as a function of the doping concentration, temperature and time. We report the concentration-dependent inhomogeneous linewidth of the nuclear transition, limited by the intrinsic host crystal properties. We determine an optimal working temperature for the 229 Th:CaF 2 nuclear clock at 196(5) K, at which the first-order thermal sensitivity vanishes. This would enable in situ temperature co-sensing using different quadrupole-split lines, reducing the temperature-induced systematic shift below the 10 −18 fractional frequency uncertainty level. At 195 K, the reproducibility of the nuclear transition frequency is 220 Hz (fractionally 1.1 × 10 −13 ) for two differently doped 229 Th:CaF 2 crystals over 7 months. Furthermore, these results form the foundation for understanding, controlling and harnessing the coherent nuclear excitation of 229 Th in solid-state hosts and for their applications in constraining temporal variations of fundamental constants.

Atomic and molecular physics↗
DOE OSTI2024

4 V Na Solid State Batteries Enabled by a Scalable Sodium Metal Oxyhalide Solid Electrolyte

All-solid-state sodium batteries (ASSSBs) are viable candidates for large scale energy storage that could vie with lithium. Ductile solid catholytes for such cells that can be prepared without extensive ball milling and directly paired with high voltage sodium cathodes are lacking, however. We report a new amorphous fast Na-ion conducting metal oxychloride that meets these criteria, synthesized through a scalable and low-cost route based on a spontaneous solid-state reaction with simple short mixing and 100 °C annealing. It has an ionic conductivity of 1.2 mS·cm–1 and low activation energy of 0.31 eV. Due to its dual O2–/Cl– framework, it exhibits a high anodic potential of 4 V vs Na+/Na and good chemical/electrochemical compatibility with high voltage sodium cathode materials. ASSSBs consisting of the oxychloride solid electrolyte paired with a high voltage P2–Na2/3Ni1/3Mn2/3O2 cathode showed stable long-term cycling with a 4.0 V vs Na3Sn cutoff potential and even to 4.3 V.

solid-state electrolyte, solid-state batteries, Nu↗
DOE OSTI2021

A high-performance organic cathode customized for sulfide-based all-solid-state batteries

All-solid-state batteries (ASSBs) have become increasingly attractive recently due to their better safety and prospective long-term stability compared with conventional liquid batteries. However, obtaining a sustainable cathode candidate to match the solid electrolyte with regards to operating potential, chemical compatibility, and mechanical property is still an open challenge. In this work, the chemical incompatibility of quinone-based active materials and sulfide-based electrolyte were unveiled for the first time through a heteroconjugate addition reaction mechanism. To develop a quinone cathode customized for sulfide-based ASSBs, poly-(anthraquinonyl sulfide)-graphene (PAQS-G) nanocomposite was reported. The stable polymer framework of PAQS can protect the quinone redox center by preventing nucleophilic attack from sulfide-based solid electrolytes. The graphene additives can ameliorate redox kinetics and improve active material utilization. The PAQS-G cathode exhibited a specific capacity of ~178 mAh g -1 and a high material utilization of ~79%. Excellent cycling stability was achieved with 94 % capacity after 200 cycles in lithium batteries and 95.5 % capacity after 300 cycles in sodium batteries at 0.1C rate, respectively. A promising potential for energy storage applications was demonstrated.

25 ENERGY STORAGE↗
DOE OSTI2020

Development of Operando Nuclear Magnetic Resonance Capabilities for Solid-State Battery Research

Mechanistic information regarding solid-solid interfaces in solid-state batteries remains elusive as its observation requires a non-destructive operando technique. Such a technique does not currently exist. Solid-state nuclear magnetic resonance (NMR) is uniquely suited to address this challenge as it is sensitive to chemistry, structure, and dynamics and can measure buried interfaces. However solid-state NMR requires high speed spinning of the sample at the ‘magic angle’ (MAS) to obtain adequate resolution. The metallic current collectors in a battery are detrimental to spinning in magnetic fields as they generate eddy currents which prevent spinning and dampen the NMR signal. Furthermore, the spinning nature of the MAS NMR experiment requires a wireless means of charging for operando capabilities. These challenges were addressed in this research and operando MAS NMR enabled by optical wireless charging was demonstrated. By limiting the size of the metallic components, we were able to spin a sample holder with electrical leads and a solid-state battery up to a few kilohertz, fast enough for high-resolution NMR. We achieved wireless charging by attaching a photovoltaic cell to the head of the NMR rotor and used a laser to transmit power to the photovoltaic cell. Demonstration of the optical wireless charging was performed by polarizing a liquid electrolyte during an operando MAS NMR measurement. This novel capability is a transformative technique for investigating the mechanistic electrochemical processes in solid-state samples.

25 ENERGY STORAGE↗