Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “interfacial resistance”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

An epoxy-reinforced ceramic sheet as a durable solid electrolyte for solid state Na-ion batteries

In a conventional Na-ion battery system using liquid electrolyte, there are critical safety issues due to the instability of the liquid electrolyte. Na 3 Zr 2 Si 2 PO 12 (NASICON) solid electrolyte is a material that is sufficient to replace a liquid electrolyte as it has high ionic conductivity and thermal and electrochemical stability. However, as there is a large interfacial resistance in the NASICON solid electrolyte powder, even when used in combination with a polymer electrolyte, the advantageous effects of ceramics are not easily exhibited. In this study, we propose a top-down method of combining a polymer with a ceramic in which an ion transport channel is previously formed. In this method, a NASICON solid electrolyte is partially sintered to form ion transport channels. Then the NASICON solid electrolyte pores are filled with an epoxy polymer to increase the strength of the epoxy-NASICON composite electrolyte. This method demonstrates the possibility of our composite electrolyte being used as a thin and strong film. As a result of our methods, the ionic conductivity and thermal and electrochemical stability of NASICON were maintained, while the physical strength was enhanced by approximately 2 times. In addition, a capacity of 120 mA h g -1 and stability of 20 cycles were confirmed in a half cell with a Na 3 V 2 (PO 4 ) 3 cathode and Na metal. This method proposes a new direction for research regarding composite electrolytes created using an oxide-based solid electrolyte.

25 ENERGY STORAGE↗
DOE OSTI2021

All solid thick oxide cathodes based on low temperature sintering for high energy solid batteries

Solid-state batteries (SSBs) could significantly improve the safety and energy density over conventional liquid cells. One key enabling technology is the use of solid electrolytes. NASICON-type Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) is a very attractive solid-state electrolyte for the cathode side due to its high oxidation potential and high ionic conductivity. The usage, however, is limited by its large interfacial resistance against most of the cathode materials as well as the thermodynamic instability during high temperature sintering needed to achieve high mass density. Here we construct thin, percolative, and mixed conductive interphases through in situ low-melting-point liquid sintering. These mixed conductive interphases drastically improve the kinetics, leading to high-loading solid LATP/LiCoO 2 cathodes achieving capacity loading of up to ~6 mA h cm –2 . The technique is also applicable to Ni-rich cathode materials, achieving up to ~10 mAh cm –2 , which can lead to more than 400 W h kg –1 cells in SSBs. Furthermore, our composite cathodes show a ten-times and three-times area capacity improvement over the state-of-the-art cathodes using oxide and sulfide SSEs, respectively.

25 ENERGY STORAGE↗
DOE OSTI2025

3D printing of architected sulfur cathodes with dual-site atomic catalysts for accelerated polysulfide kinetics and Li-ion transport in high areal-loading lithium–sulfur batteries

The practical deployment of lithium–sulfur batteries (LSBs) is hindered by fundamental limitations in conventional slurry-cast cathodes, including poor sulfur utilization, sluggish ion transport, and low areal capacity, particularly in thick electrodes required for high energy density. To address these challenges, we present direct ink writing (DIW) as an additive manufacturing strategy to fabricate advanced current-collector-free, 3D-printed sulfur cathodes (3DP S@CoNi-DSACs/NC) with hierarchically porous architectures that enhance lithium-ion diffusion, promote electrolyte penetration, and reduce interfacial resistance. The synergistic effects of Co/Ni dual-atom sites accelerate redox kinetics and mitigate polysulfide shuttling. As a result, the optimized 3DP cathode with a sulfur loading of 5.4 mg cm −2 demonstrated excellent rate capability, delivering a high reversible capacity of 1041.4 mAh g −1 at 1C with 85.5% capacity retention after 1000 cycles, significantly outperforming its cast counterpart. Remarkably, even at a higher sulfur loading of 8.1 mg cm −2 , the 3DP cathode maintains outstanding performance, achieving a discharge capacity of 1538.4 mAh g −1 and an areal capacity of 12.5 mAh cm −2 at 0.1C. This study not only demonstrates the functional integration of catalytically active materials into 3D printable sulfur cathode architectures but also offers a scalable and transformative platform for building high-performance LSBs beyond conventional electrode manufacturing methods.

3D electrode↗
DOE OSTI2022

Impedance Modeling for Mixed Conductors with Simultaneous Insertion & Electrocatalytic Reactions: A Case Study of Transition-Metal Hydroxides in Aqueous Electrolyte

Electrochemical impedance spectroscopy (EIS) is commonly used to investigate the kinetics of mixed ionic–electronic conductor (MIEC) electrodes. Across various applications, MIECs exhibit ionic (e.g., insertion) and/or electronic (e.g., electrocatalytic) charge transfer reactions at the electrode/electrolyte interface. Bulk storage and transport of charge carriers also couple with these interfacial reactions. Here, we build a generalized, physics-based impedance model for MIECs with an ion-blocking current collector and explore how bulk and interfacial resistance, chemical capacitance, and DC polarization affect the impedance response. Using transition metal hydroxides as a case study, we provide guidance on extracting reaction kinetics or bulk resistance from the Nyquist plots in interface- or bulk-controlled conditions, respectively. Generalizing our EIS analysis enables a robust analysis of MIEC kinetics for a diverse set of systems.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Metallic Cu Surface Enables Reversible Na Metal Anodes and Stabilizes Anode-Free Sodium Metal Batteries

Anode free Na metal batteries are promising for future energy storage because they not only provide the highest energy densities but also eliminate the need of handling hazardous Na metals during battery manufacturing. However, they suffer from much faster degradation due to strong sensitivities even to trace levels of side reactions. In view of the crucial roles of surface chemistry on modulating electrochemical plating, this work systematically investigated a series of Cu surfaces for Na plating and stripping in the 1.0 M NaPF 6 diglyme electrolyte. Our results suggest that Na plating and stripping on pure Cu surface without Cu oxide species exhibits much better reversibility and smaller overpotentials across a wide range of current densities, especially for the first plating/stripping cycle. The high performance includes consistently higher than 99.8% Faradaic efficiencies, much more stable interfacial resistance, and negligible formation of mossy Na after 500 cycles. This improved performance can be explained based on the stronger Na-Cu affinity compared with the Na-CuO affinity. Anode-free Na metal batteries equipped with high-capacity sodium vanadium phosphate cathodes and pure Cu current collector exhibited at least 70% capacity retention for 100 cycles.

Electrochemistry↗
DOE OSTI2026

Plasticizer-Free Gradient-Crosslinked Polyurethane Electrolyte for Room-Temperature Solid-State Lithium Batteries

Polymer-based solid-state electrolytes are promising for next-generation lithium metal batteries, yet their limited ionic conductivity and mechanical stability at ambient conditions remain key challenges. Herein, we report a novel gradient crosslinked polymer electrolyte (PU/PUA/PU) synthesized via a sequential in situ UV-curing process that integrates a mechanically robust polyurethane acrylate (PUA) core with soft linear polyurethane (PU) interfaces. This all-solid membrane operates without any liquid plasticizer and the interfacial PU layers ensure low interfacial resistance and intimate electrode contact, while the PUA core provides enhanced dimensional stability and dendrite suppression. As a result, the gradient electrolyte delivers an impressive ∼2.6 × 10 −4 S cm −1 ionic conductivity at 25 °C (two orders of magnitude higher than conventional PEO) and remains electrochemically stable >5 V (vs Li + /Li). Structural analysis confirms the formation of a well-defined crosslinked network with suppressed crystallinity and expanded interchain spacing. Electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) further validate these properties. When applied in a Li||NMC811 cell, the PU/PUA/PU electrolyte delivers stable cycling with high capacity at both 60 °C and 25 °C, demonstrating its potential for room-temperature solid-state battery applications without reliance on plasticizers or heating. In conclusion, this gradient design offers a practical path toward ambient-condition operation of solid-state lithium batteries, providing a paradigm for overcoming the traditional trade-off between ionic conductivity and mechanical robustness.

25 ENERGY STORAGE↗
DOE OSTI2021

Scaling-Up and Roll-to-Roll Processing if Highly Conductive Sulfide Solid-State Electrolytes (CRADA 510)

This project aims to identify and address key technical barriers in scale-up synthesis and roll-to-roll processing of highly conductive solid-state electrolytes (SSEs) by leveraging PNNL’s patent pending SSEs, Ampcera Inc.’s environmentally friendly manufacturing capability, and UW’s rollto-roll processing. The ultimate goals are 1) development of novel sulfide SSEs with room temperature Li+ conductivity > 5 mS/cm and Li/SSE interfacial resistance <5 Ωcm2, 2) scalable production of sulfide SSEs at 1 metric ton/year, and 3) a high throughput roll-to-roll processing of highly conductive (>1 mS/cm) and ultra-thin solid film (10-100 μm). The materials and the solid film achieved in the project will be tested at practical conditions and validated in a realistic pouch cell format with achievable energy > 300 Wh/Kg.

36 MATERIALS SCIENCE↗
DOE OSTI2021

3D Printed, Low Tortuosity Garnet Framework For Beyond 500 Wh/kg Batteries

In this project, we developed LLZO garnet ink recipes and processes for 3D-printing highly ordered ionically conductive garnet porous structures on dense garnet separators. Using this technique, we are able to fabricate controlled architecture LLZO garnet solid-state electrolyte (SSE) trilayers for application in solid-state lithium batteries. The trilayer comprises a thin dense center layer sandwiched between a 3D-printed patterned porous layer and a random porous layer. The dense layer functions as the ionic separator between the anode and cathode. The random porous layer hosts the lithium-metal anode and provides the structural support. The 3D-printed SSE patterned porous layer hosts the cathode, providing continuous, low tortuosity pathways for fast 3D Li+ transport through the cell while increasing the electrode/electrolyte interface area to decrease the interfacial resistance. Compared to the random porous structure, this ordered patterned structure possesses more vacant space for higher cathode loading without sacrificing ionically conducting capability, thus potentially greatly increasing the cell energy density. For demonstration purposes, we developed two patterns for the 3D-printed porous layer: grids and columns, for hosting sulfur and NMC cathode, respectively. The corresponding two types of cells were fabricated and tested, and have demonstrated achievement of theoretical discharge capacity without cathode calendaring. In addition, we developed a fundamental solid-state ionic and electronic transport model to optimize the 3D-printed structures for maximum energy and power density. The model was validated by experiment and provides the critical design criteria for achieving the >500 Wh/kg energy goal as function of C-rate.

25 ENERGY STORAGE↗
DOE OSTI2020

Recent Developments and Challenges in Hybrid Solid Electrolytes for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) have attracted worldwide research interest due to their high energy density and long cycle life. Solid-state LIBs improve the safety of conventional liquid-based LIBs by replacing the flammable organic electrolytes with a solid electrolyte. Among the various types of solid electrolytes, hybrid solid electrolytes (HSEs) demonstrate great promise to achieve high ionic conductivity, reduced interfacial resistance between the electrolyte and electrodes, mechanical robustness, and excellent processability due to the combined advantages of both polymer and inorganic electrolyte. This article summarizes recent developments in HSEs for LIBs. Approaches for the preparation of hybrid electrolytes and current understanding of ion-transport mechanisms are discussed. The main challenges including unsatisfactory ionic conductivity and perspectives of HSEs for LIBs are highlighted for future development. The present review provides insights into HSE development to allow a more efficient and target-oriented future endeavor on achieving high-performance solid-state LIBs.

25 ENERGY STORAGE↗
DOE OSTI2025

Titanium Nitride as an Intermetallic Diffusion Barrier for Hydrogen Permeation in Palladium–Vanadium Composite Membranes

Hydrogen purification is a critical industrial process, and there are ongoing efforts to develop low-cost alternatives to palladium foil membranes. Titanium nitride (TiN) is studied as an interdiffusion barrier to enable hydrogen permeation in composite palladium–vanadium membranes. TiN was deposited via reactive sputtering, and films with the desired (200) orientation were obtained in the metallic regime at 400 °C under a 200 V bias to the substrate. The permeability of thin-film TiN was determined with palladium-based sandwich structures. TiN layers up to 10 nm resulted in a minimal decrease in flux (~20%) relative to a freestanding PdCu foil, which was attributed to the interfacial resistance. At greater thicknesses, the TiN layer was rate-limiting, and it was found that the effective permeability of the sputtered TiN thin films was ~6 × 10−12 mol s−1 m−1 Pa−0.5. Composite Pd|TiN|V|TiN|Pd membranes exhibited permeability values up to three times greater than pure palladium, exhibiting stability at 450 °C for over 100 h, with the lack of intermetallic diffusion and alloy formation being confirmed with XRD. The membranes were unstable at 500 °C, which was attributed to the instability of the thin Pd layer and loss of catalytic activity.

Biochemistry & Molecular Biology↗
DOE OSTI2023

Sodium electrochemical interfaces with NaSICON-type ceramics

The present invention is directed to the modification of sodium electrochemical interfaces to improve performance of NaSICON-type ceramics in a variety of electrochemical applications. Enhanced mating of the separator-sodium interface by means of engineered coatings or other surface modifications results in lower interfacial resistance and higher performance at increased current densities, enabling the effective operation of molten sodium batteries and other electrochemical technologies at low and high temperatures.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Methods of fabricating porous ceramic electrodes for solid state battery applications

Compositions and methods for the fabrication of electrode and porous lithium-garnet electrolyte scaffolds for use in solid state batteries and other devices are provided. The methods produce porous structures using phase inversion or high shear compaction processes to fabricate a solid-state battery electrode material from LLZO electrolytes. Engineered electrode structures with a porous scaffold of solid electrolyte material provide lower interfacial resistances and a mechanical support for a thin solid electrode layer improving performance.

Tucker, Michael↗
DOE OSTI2026

Tunable Interfacial to Filamentary Resistive Switching Mechanism in Room-Temperature-Grown Amorphous YBa 2 Cu 3 O x with Excess Cu Addition

Resistive switching technologies have the potential not only to create large efficiency gains in computer memory but also to revolutionize emerging fields such as neuromorphic computing. In this paper, we report on novel resistive switching behavior in devices made from room-temperature-grown Cu-rich amorphous YBa 2 Cu 3 O x (YBCO) films, a material otherwise well-known as a high-temperature superconductor. In Nb:STO substrate/amorphous YBCO film (≈200 nm)/metallic Cu (15 nm)/metallic Pt (15 nm) devices, we demonstrate that the resistive switching can be tuned between mechanisms involving extended areas of the YBCO/electrode interface and a single-point filamentary mechanism simply by changing the Cu content of the deposition target and hence in the films. Changing the Cu content can also be used to optimize the properties of the devices further, with devices with an added 15 mol % of Cu in YBCO initially providing an on/off ratio >100, switching endurance potential >6500 cycles, and state retention >2 × 10 4 s, all at low switching fields of 0.3 MV/cm. The amalgam of promising resistive switching properties, fast growth (150 nm/min) at room temperature, and tuneability of the switching mechanism indicates the strong potential of this proof-of-concept amorphous system for future memory applications.

Cu↗
DOE OSTI2024

Enhanced Radiation Damage Tolerance of Amorphous Interphase and Grain Boundary Complexions in Cu-Ta

Amorphous interfacial complexions are particularly resistant to radiation damage and have been primarily studied in alloys with good glass-forming ability, yet recent reports suggest that these features can form even in immiscible alloys such as Cu-Ta under irradiation. In this work, the mechanisms of damage production and annihilation due to primary knock-on atom collisions are investigated for amorphous interphase and grain boundaries in a Cu-Ta alloy using atomistic simulations. Amorphous complexions, in particular amorphous interphase complexions that separate Cu and Ta grains, result in less residual defect damage than their ordered counterparts. Stemming from the nanophase chemical separation in this alloy, the amorphous complexions exhibit a highly heterogeneous distribution of atomic excess volume, as compared to a good glass former like Cu-Zr. Complexion thickness, a tunable structural descriptor, plays a vital role in damage resistance. Thicker interfacial films are more damage-tolerant because they alter the defect production rate due to differences in intrinsic displacement threshold energies during the collision cascade. Overall, the findings of this work highlight the importance of interfacial engineering in enhancing the properties of materials operating in radiation-prone environments and the promise of amorphous complexions as particularly radiation damage-tolerant microstructural features.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Expression of interfacial Seebeck coefficient through grain boundary engineering with multi-layer graphene nanoplatelets

Energy filtering has been a long-sought strategy to enhance a thermoelectric material's figure of merit zT through improving its power factor. Here we show a composite of multi-layer graphene nanoplatelets (GNP) and n-type Mg 3 Sb 2 leads to the expression of an energy filtering like effect demonstrated by an increase in the material's Seebeck coefficient and maximum power factor, without impact on the material's carrier concentration. We analyse these findings from the perspective of a heterogeneous material consisting of grain and grain boundary phases, instead of a more traditional and common analysis that assumes a homogeneously transporting medium. An important implication of this treatment is that it leads to the development of an interfacial Seebeck coefficient term, which can explain the observed increase in the material's Seebeck coefficient. The contribution of this interfacial Seebeck coefficient to the overall Seebeck coefficient is determined by the relative temperature drop across the grain boundary region compared to that of the bulk material. In Te doped Mg 3 Sb 2 we show the introduction of GNP increases the interfacial thermal resistance of grain boundaries, enhancing the contribution of the interfacial Seebeck coefficient arising from grain boundaries to the overall Seebeck coefficient. Without significant detriment to the electrical conductivity this effect results in a net increase in maximum power factor. This increased interfacial thermal resistance also leads to the synergistic reduction of the total thermal conductivity. As a result, we enhance zT of the Mg 3 Sb 2 to a peak value of 1.7 near 750 K. Considering the two-dimensional nature of the grain boundary interface, this grain boundary engineering strategy could be applied to a few thermoelectric systems utilizing various two-dimensional nanomaterials.

42 ENGINEERING↗
DOE OSTI2026

Coupled Interfacial Kinetics and Transport Resistances Govern High-Current Behavior in Bipolar Membranes

Bipolar membranes (BPMs) enable electrochemical systems that operate across large pH gradients; however, high-current operation is often limited by voltage losses whose origins remain difficult to resolve in membrane−electrode assemblies. Here, we combine electrochemical impedance spectroscopy with distribution of relaxation times (EIS–DRT) analysis and operando synchrotron X-ray diffraction to examine interfacial polarization, membrane hydration, and transport in commercial and synthesized BPMs. EIS–DRT isolates the BPM-associated interfacial contribution and shows that the commercial BPM exhibits larger water-dissociation-associated overpotentials than the synthesized BPM. Operando hydration mapping shows that both membranes retain water at the bipolar junction during high-current operation, while anode-adjacent hydration gradients are more pronounced in the commercial membrane. These results indicate that high-current voltage losses are not governed by junction water starvation alone but by coupled interfacial polarization and transport resistances.

36 MATERIALS SCIENCE↗