Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “all solid electrodes”

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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Semi-solid electrodes with a polymer additive

Embodiments described herein relate generally to electrochemical cells having semi-solid electrodes that include a gel polymer additive such that the electrodes demonstrate longer cycle life while significantly retaining the electronic performance of the electrodes and the electrochemical cells formed therefrom. In some embodiments, a semi-solid electrode can include about 20% to about 75% by volume of an active material, about 0.5% to about 25% by volume of a conductive material, and about 20% to about 70% by volume of an electrolyte. The electrolyte further includes about 0.01% to about 1.5% by weight of a polymer additive. In some embodiments, the electrolyte can include about 0.1% to about 0.7% of the polymer additive.

Tan, Takahiro↗
DOE OSTI2023

Semi-solid electrodes with a polymer additive

Embodiments described herein relate generally to electrochemical cells having semi-solid electrodes that include a gel polymer additive such that the electrodes demonstrate longer cycle life while significantly retaining the electronic performance of the electrodes and the electrochemical cells formed therefrom. In some embodiments, a semi-solid electrode can include about 20% to about 75% by volume of an active material, about 0.5% to about 25% by volume of a conductive material, and about 20% to about 70% by volume of an electrolyte. The electrolyte further includes about 0.01% to about 1.5% by weight of a polymer additive. In some embodiments, the electrolyte can include about 0.1% to about 0.7% of the polymer additive.

Tan, Taison↗
DOE OSTI2021

Semi-solid electrodes having high rate capability

Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode and a semi-solid cathode. The semi-solid cathode includes a suspension of an active material of about 35% to about 75% by volume of an active material and about 0.5% to about 8% by volume of a conductive material in a non-aqueous liquid electrolyte. An ion-permeable membrane is disposed between the anode and the semi-solid cathode. The semi-solid cathode has a thickness of about 250 μm to about 2,000 μm, and the electrochemical cell has an area specific capacity of at least about 7 mAh/cm2 at a C-rate of C/4. In some embodiments, the semi-solid cathode slurry has a mixing index of at least about 0.9.

Chiang, Yet-Ming↗
DOE OSTI2023

Semi-solid electrodes having high rate capability

Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cells includes an anode and a semi-solid cathode. The semi-solid cathode includes a suspension of an active material of about 35% to about 75% by volume of an active material and about 0.5% to about 8% by volume of a conductive material in a non-aqueous liquid electrolyte. An ion-permeable membrane is disposed between the anode and the semi-solid cathode. The semi-solid cathode has a thickness of about 250 μm to about 2,000 μm, and the electrochemical cell has an area specific capacity of at least about 7 mAh/cm 2 at a C-rate of C/4. In some embodiments, the semi-solid cathode slurry has a mixing index of at least about 0.9.

Chiang, Yet-Ming↗
DOE OSTI2023

Challenges and Prospects of All-Solid-State Electrodes for Solid-State Lithium Batteries

In the development of all-solid-state lithium batteries (ASSLB), progress is made with solid-state electrolytes; however, challenges regarding compatibility and stability still exist with solid electrodes. These issues result in a low battery capacity and short cycle life, which limit the commercial application of ASSLBs. Here, this review summarizes the recent research progress on solid-state electrodes in ASSLBs including the solid–solid interface phenomena such as the interface between electrode materials and electrolytes. The mechanical stability problems in solid electrodes, including fracture, brittleness, and deformation of electrode materials, are also discussed, and corresponding methods to measure the solid electrode stress are provided. In addition, strategies for mitigating stress-related issues are examined. Finally, the fabrication process of solid electrodes is introduced and their future developments, including the exploration of new electrode materials and the design of more intelligent electrode structures, are proposed.

25 ENERGY STORAGE↗
DOE OSTI2024

Glassy embedded solid-state electrode assemblies, solid-state batteries and methods of making electrode assemblies and solid-state batteries

Batteries, component structures and manufacturing methods, in particular including a glassy embedded battery electrode assembly having a composite material structure composed of interpenetrating material components including a porous electroactive network including a solid electroactive material, and a continuous glassy medium including a Li ion conducting sulfide glass, can achieve enhanced power output, reduced charging time and/or improved cycle life.

Visco, Steven J.↗
DOE OSTI2025

Improving durability and performance of solid oxide electrolyzers by controlling surface composition on oxygen electrodes

Solid oxide electrolysis cell (SOEC) is a promising technology for high-efficiency energy conversion, enabling the production of hydrogen, syngas, synthetic fuels, and various commodity chemicals. Unlike traditional thermochemical processes, SOECs operate at elevated temperatures (600-850°C), benefiting from favorable thermodynamics and reaction kinetics. This makes them highly energy efficient compared to alkaline or polymer electrolyte membrane (PEM) electrolysis technologies. However, despite these advantages, SOECs face significant challenges related to performance degradation over time. A primary issue is the degradation of the oxygen electrode due to strontium (Sr) segregation and impurity poisoning from chromium (Cr) and sulfur (S). This is because the pathway to deposition of Cr and S include the reaction of Cr and S with the segregated SrO at the surface. Sr segregation leads to the formation of insulating compounds such as SrCrO4 and SrSO4, which block active sites, reduce oxygen exchange rates, and compromise the electrode's electrochemical stability. The degradation mechanisms involve complex interactions between the electrode material's surface chemistry, microstructure, and the operating environment. Sr segregation is particularly problematic because it facilitates the deposition of Cr and S impurities, exacerbating performance losses. Addressing these issues is critical to enhancing the durability and economic viability of SOEC technology. The primary goal of this project is to improve the durability and performance of SOECs by controlling the surface composition of the oxygen electrode. This is achieved by suppressing Sr segregation, thereby mitigating impurity poisoning pathways. The project aims to enhance the oxygen exchange rate, improve cell stability, and extend the operational lifespan of SOECs without necessitating major changes to electrode chemistry or stack components.

30 DIRECT ENERGY CONVERSION↗
NASA NTRS2012

Solid State Multinuclear Magnetic Resonance Investigation of Electrolyte Decomposition Products on Lithium Ion Electrodes

Solid electrolyte interphase (SEI) formation in lithium ion cells prepared with advanced electrolytes is investigated by solid state multinuclear (7Li, 19F, 31P) magnetic resonance (NMR) measurements of electrode materials harvested from cycled cells subjected to an accelerated aging protocol. The electrolyte composition is varied to include the addition of fluorinated carbonates and triphenyl phosphate (TPP, a flame retardant). In addition to species associated with LiPF6 decomposition, cathode NMR spectra are characterized by the presence of compounds originating from the TPP additive. Substantial amounts of LiF are observed in the anodes as well as compounds originating from the fluorinated carbonates.

Li-ion battery electrolytes↗
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 OSTI2020

Advanced oxygen-electrode-supported solid oxide electrochemical cells with Sr(Ti,Fe)O 3–δ -based fuel electrodes for electricity generation and hydrogen production

Sr(Ti 0.3 Fe 0.7 )O 3–δ (STF) and the associated exsolution electrodes Sr 0.95 (Ti 0.3 Fe 0.63 Ru 0.07 )O 3–δ (STFR), or Sr 0.95 (Ti 0.3 Fe 0.63 Ni 0.07 )O 3–δ (STFN) are alternatives to Ni-based cermet fuel electrodes for solid oxide electrochemical cells (SOCs). They can provide improved tolerance to redox cycling and fuel impurities, and may allow direct operation with hydrocarbon fuels. However, such perovskite-oxide-based electrodes present processing challenges for co-sintering with thin electrolytes to make fuel electrode supported SOCs. Thus, they have been mostly limited to electrolyte-supported SOCs. Here, we report the first example of the application of perovskite oxide fuel electrodes in novel oxygen electrode supported SOCs (OESCs) with thin YSZ electrolytes, and demonstrate their excellent performance. The OESCs have La 0.8 Sr 0.2 MnO 3–δ –Zr 0.92 Y 0.16 O 2–δ (LSM–YSZ) oxygen electrode-supports that are enhanced via infiltration of SrTi 0.3 Fe 0.6 Co 0.1 O 3–δ , while the fuel electrodes are either Ni-YSZ, STF, STFN, or STFR. Fuel cell power density as high as 1.12 W cm –2 is obtained at 0.7 V and 800 °C in humidified hydrogen and air with the STFR electrode, 60% higher than the same cell made with a Ni-YSZ electrode. Electrolysis current density as high as –1.72 A cm –2 is obtained at 1.3 V and 800 °C in 50% H 2 O to 50% H 2 mode; the STFR cell yields a value 72% higher than the same cell made with a Ni-YSZ electrode, and competitive with the widely used conventional Ni-YSZ-supported cells. The high performance is due in part to the low resistance of the thin YSZ electrolyte, and also to the low fuel electrode polarization resistance, which decreases with fuel electrode in the order: Ni-YSZ > STF > STFN > STFR. The high performance of the latter two electrodes is due to exsolution of catalytic metal nanoparticles; the results are discussed in terms of the microstructure and properties of each electrode material, and surface oxygen exchange resistance values are obtained over a range of conditions for STF, STFN, and STFN. Furthermore, the STF fuel electrodes also provide good stability during redox cycling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2009

Symmetrical, bi-electrode supported solid oxide fuel cell

The present invention is a symmetrical bi-electrode supported solid oxide fuel cell comprising a sintered monolithic framework having graded pore electrode scaffolds that, upon treatment with metal solutions and heat subsequent to sintering, acquire respective anodic and cathodic catalytic activity. The invention is also a method for making such a solid oxide fuel cell. The graded pore structure of the graded pore electrode scaffolds in achieved by a novel freeze casting for YSZ tape.

Cable, Thomas L.↗
DOE OSTI2021

Metal infiltrated electrodes for solid state batteries

Disclosed are electrochemical devices and methods for making electrochemical devices such as metal infiltrated electrodes for solid state lithium ion and lithium metal batteries. In one method for forming an electrode, a metal is infiltrated into the pore space of the active material of the electrode providing improved electronic conductivity to the electrode. The electrode may also include a solid-state ion conducting material providing improved ion conductivity to the electrode. Before infiltration of the metal, a stabilization coating may be applied to the active material and/or the solid-state ion conducting material to the stabilize electrode interfaces by slowing, but not eliminating, the chemical reactions that occur at elevated temperatures during sintering of the active material and/or the solid-state ion conducting material forming the electrode.

Sakamoto, Jeffrey↗
DOE OSTI2024

Ni coarsening under humid atmosphere in the electrode of solid oxide cells: A combined study of density-functional theory and phase-field modeling

Ni coarsening in solid oxide cell (SOC) electrodes is known to be significantly faster under a humid atmosphere. The underlying mechanisms, though, have not been fully understood. In this work, we examine the surface diffusion of Ni(OH) x by a combination of density-functional theory and phase-field modeling. Here, density-functional theory is used to evaluate the adsorption and diffusion of the Ni(OH) x species on Ni (111) surface, and the results are used to obtain the effective surface diffusivity of Ni versus steam and hydrogen gas partial pressures. This diffusivity is used as an input for a phase-field model to investigate the Ni coarsening in SOC electrodes. It is found that Ni(OH) x formed through chemical reaction cannot accelerate coarsening unless an extremely high steam to hydrogen ratio is reached. However, if Ni(OH) x is formed through electrochemical reactions near triple phase boundaries (TPBs), surface diffusion of Ni(OH) x may cause faster Ni coarsening in fuel cell mode under a large overpotential. Specifically, surface diffusion of Ni(OH) may be comparable to or faster than that of Ni under an overpotential that is large but still possible under fuel cell operating conditions.

25 ENERGY STORAGE↗
DOE OSTI2021

Creating and Preserving Nanoparticles during Co-Sintering of Solid Oxide Electrodes and Its Impact on Electrocatalytic Activity

A novel processing method that creates and preserves ceramic nanoparticles in solid oxide electrodes during co-sintering at traditional sintering temperatures is introduced. Specifically, carbon templated samarium-doped ceria nanoparticles (nSDC) were successfully integrated with commercial lanthanum strontium cobalt ferrite (LSCF) and commercial SDC powders, producing LSCF-SDC-nSDC cathodes upon processing. The effect of nSDC concentration on cathode electrocatalytic activity was investigated at low operational temperatures, 600 °C–700 °C, with symmetrical cells. Low nSDC loadings, ≤5 wt% nSDC, significantly decreased cell polarization resistance whereas higher loadings increased it. The best electrochemical performance was achieved with 5 wt% nSDC, lowering the polarization resistance by 41% at 600 °C. Fuel cell tests demonstrate that adding 5 wt% nSDC increased the maximum fuel cell power density by 38%. Electrochemical impedance spectra showed substantial improvements in both fuel cell polarization resistance and ohmic resistance, indicating that nSDC increased the electrocatalytically active area of the cathode. This work demonstrates a simple, novel method for effectively increasing electrocatalytic activity of solid oxide electrodes at low operational temperatures.

Muhoza, Sixbert P. (ORCID:0000000299864241)↗
DOE OSTI2023

The role of ionic liquids in resolving the interfacial chemistry for (quasi-) solid-state batteries

Interfacial issues impede the advancement of current solid state battery technology; thus, interface engineering approaches are necessary to enable solid-state configuration. The advantage of solid-state cells stems from their low flammability and high electrochemical stability. Ionic liquids are viscous and nonflammable compounds that possess the requisite physical properties while optimizing the interface between solid electrodes and solid electrolytes, accelerating interfacial ion transport and enabling the fabrication of engineered interphases via the supply of robust chemical building blocks. In conclusion, this review summarizes the roles of ionic liquids in solid-state batteries focusing on the interface, with insights into their functionality as well as highlighting their applicability in the next generation battery systems.

25 ENERGY STORAGE↗
DOE OSTI2023

Atomic layer deposition for surface area determination of solid oxide electrodes

Surface area measurements are important for characterizing porous solids, but commonly used methods such as Brunauer–Emmett–Teller (BET) gas adsorption and computed nanotomography are lacking for certain applications such as the development of solid oxide fuel cell electrodes, which often have absolute surface areas <1 m 2 and contain nanoscale features. Presented is a novel method for the surface area determination of samples with total measurable areas of 1–1000 cm 2 with a standard deviation ± 1 cm 2 , utilizing the atomic layer deposition (ALD) of Al 2 O 3 over microstructurally complex internal porosity. The volume of alumina is then quantified using plasma spectroscopy and converted to an area using the known ALD layer thickness. Under the modest ALD reactor soak times used (8.5 s), the precursor penetration depth is found to be ~50 μm, exceeding the requirement for uniformly coating SOFC functional layers. A model system, (La 0.8 Sr 0.2 ) 0.98 MnO 3–δ /Ce 0.9 Gd 0.1 O 1.95 (LSM/GDC) scaffolds of ~2.7 m 2 g –1 , was measured using the technique and compared against the BET method, and comparable results were obtained but with 1000 times less material needed. The technique is demonstrated for measurements in two example areas of active SOFC research: exsolved (Ni, Fe) nanoparticles on an Sr(Ti, Fe, Ni)O 3–δ electrode and PrO x catalyst nanoparticles infiltrated onto LSM/GDC scaffolds. Finally, the technique may be broadly useful wherever the accurate surface area determination of small absolute quantities of porous ceramic structures on the order of 0.1–50 m 2 g –1 is sought.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Fundamental study of gas species transport in the oxygen electrode of solid oxide fuel and electrolysis cells

A fundamental analysis of multicomponent gas transport models was performed in application to the oxygen electrodes of solid oxide cells. It is common practice to neglect the effect of pressure gradients within oxygen electrodes, even though a net molar flux at the electrolyte surface implies that a pressure gradient must exist. The influence of both Darcy velocity and Knudsen flux are considered in the context of ordinary (Fickian) diffusion, the dusty gas model, and the binary friction model. Comparisons between the models and different sets of assumptions are made via parametric studies on operating load, oxygen partial pressure, microstructural properties, and electrode thickness. Results show that the pressure gradient will have a significant impact on the oxygen concentration distribution and therefore the concentration overpotential. In electrolysis mode, pressure increases up to 1 atm are predicted, indicating that pressure at the electrode/electrolyte interface could contribute to electrode delamination. Additionally, it is found that Darcy's law is insufficient for calculating the pressure distribution without accounting for the flux due to Knudsen diffusion. Additionally, it is found that for the range of properties typical of oxygen electrodes, there is a negligibly small difference between the dusty gas model and binary friction model from a practical standpoint.

08 HYDROGEN↗
DOE OSTI2024

Modeling Ni Coarsening and Migration in the Hydrogen Electrode of Solid oxide Cells under Operating Conditions

Ni coarsening and migration is the most important degradation in the hydrogen electrode of solid oxide cells. This presentation reviews our works on Ni coarsening and migration in NETL over the past years. We used simulation techniques including phase-field modeling and density function theory to investigate possible mechanisms of Ni coarsening and migration, including self-diffusion of Ni, diffusion of gaseous Ni(OH)2, surface diffusion of Ni(OH)x and Ni-YSZ wettability change, and examined the effect of operating conditions on these mechanisms. So far, none of the mechanisms can fully explain the experiments. Remaining questions and possible paths forward are summarized and discussed.

Lei, Yinkai↗