Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “electrolyte costs”

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 433 records · Page 24

Method for Surface Texturing Titanium Products

The present invention teaches a method of producing a textured surface upon an arbitrarily configured titanium or titanium alloy object for the purpose of improving bonding between the object and other materials such as polymer matrix composites and/or human bone for the direct in-growth of orthopaedic implants. The titanium or titanium alloy object is placed in an electrolytic cell having an ultrasonically agitated solution of sodium chloride therein whereby a pattern of uniform "pock mark" like pores or cavities are produced upon the object's surface. The process is very cost effective compared to other methods of producing rough surfaces on titanium and titanium alloy components. The surface textures produced by the present invention are etched directly into the parent metal at discrete sites separated by areas unaffected by the etching process. Bonding materials to such surface textures on titanium or titanium alloy can thus support a shear load even if adhesion of the bonding material is poor.

Banks, Bruce A.↗

Reaction Mechanism of Electrodeposited ε-MnO 2 : A Proton-Centered Pathway in Aqueous Zn-Ion Systems

Aqueous Zn/MnO 2 batteries have garnered significant interests owing to their abundance, high theoretical specific capacity, safety, and low cost. However, large-scale application of these systems is limited by the incomplete understanding of the MnO 2 reaction chemistry. The different crystal lattice structures among MnO 2 polymorphs contribute to the variations in reported reaction mechanisms. Among them, ε-MnO 2 polymorph, the dominant phase in electrolytic manganese dioxide (EMD), is notably observed during the charge cycles of aqueous Zn/MnO 2 batteries. Here, in this work, we investigate the electrochemical behavior of an ε-MnO 2 cathode synthesized via electrodeposition from a ZnSO 4 and MnSO 4 electrolyte, onto a 3-dimensional carbon cloth substrate. Proton intercalation emerges as the dominant charge storage mechanism, critically enabling the reversibility of ε-MnO 2 during cycling, as revealed by operando synchrotron X-ray diffraction and X-ray absorption spectroscopy. Additionally, a proton-coupled dissolution/redeposition pathway operates alongside minor Zn 2+ intercalation, as quantified by Rietveld refinement. Morphological and chemical heterogeneities are studied by transmission X-ray microscopy further validates this reaction mechanism. These mechanistic insights provide the foundation for rationally designing Zn/MnO 2 batteries with optimized proton dynamics and charge transfer, advancing these systems as a viable solution for safe, cost-effective grid-scale energy storage.

36 MATERIALS SCIENCE↗

Hydrogen Carriers for Renewable Microgrid System Applications

Utility-scale energy storage can help improve grid reliability, reduce costs, and promote faster adoption of intermittent sources such as solar and wind. This paper analyzes the technical aspects and economics of standalone microgrids operating on intermittent power combined with hydrogen energy storage. It explores the feasibility of using dibenzyltoluene (DBT) as a liquid organic hydrogen carrier to absorb excess energy during periods of high supply and polymer electrolyte fuel cells to generate electrical energy during periods of low supply. A comparative analysis is conducted on three power demand scenarios (industrial, residential, and office), in conjunction with three alternative energy sources: solar, wind and wind–solar mix. A mixed system of solar and wind energy can maintain an annual average efficiency above 70%, except for residential power demand, which lowered the efficiency to 67%. A balanced combination of wind and solar power was the most cost-effective option. The current levelized cost of electricity (LCOE) for industrial power demand was estimated to 15 ¢/kWh, and it is projected to decrease to 9 ¢/kWh in the future. For residential power demand, the LCOE was 45% higher due to the demand profile. In comparison, battery storage is significantly more expensive than hydrogen storage, even with future cost projections, increasing the LCOE between 60 and 120 ¢/kWh.

PEM electrolysis↗

Fibrous Materials for Flexible Li–S Battery

The lithium–sulfur (Li–S) battery is an attractive high-energy-density technology for future flexible and wearable electronics, but it is a challenge to simultaneously realize adequate flexibility, stability, and energy density. Recent studies show that fibrous materials are promising to achieve flexible batteries with high energy density, by taking advantages of their intrinsic flexibility, lightweight, large surface area, and cost-effectiveness. With a good tunability of the structure and function, fibrous materials can be suitable to construct various components of a working battery, including current collectors, buffer layers, interlayers, and solid-state electrolytes. In this review, we summarize the recent development of fibrous materials for flexible Li–S batteries, with an emphasis on the discussion of the synthesis and preparation of materials, design of fibrous structures and functionalities, and layout of battery cells for achieving high Coulombic efficiency, long cycle life, and good flexibility.

25 ENERGY STORAGE↗

Phosphate tolerance of nitrogen-coordinated-iron-carbon (FeNC) catalysts for oxygen reduction reaction: A size-related hindrance effect

The greatest challenges facing the large – scale commercialization of the intermediate temperature phosphoric acid fuel cell (PAFC) technology are: (i) the high cost of Pt catalyst that is required to overcome the slow kinetics of oxygen reduction reaction (ORR) on the PAFC cathode, and (ii) deactivation of the Pt catalyst by exposure to the phosphoric acid electrolyte. Inexpensive carbon-based materials, particularly iron- spectroscopy is used to explore the phenomenon of phosphate poisoning nitrogen-coordinated carbon supported catalysts (FeNC), are promising cathodes for PAFCs. The higher ORR activation energy and phosphate poisoning resistance of FeNC present a clear advantage over the Pt-based commercial catalysts that are easily susceptible to deactivation after exposure to phosphate anions. While the immunity of FeNC catalysts to phosphate anion poisoning has been reported previously, this work explores the counter-intuitive and conditional nature of this poisoning resistance based on the properties of the carbon support used in the preparation of the FeNC catalyst. Additionally, a combination of electrochemical measurements with characterization experiments performed using X-ray photoelectron spectroscopy, infrared spectroscopy and in-situ X-ray absorption on FeNC catalysts synthesized from two different carbon supports. Results from these studies reveal a “size-related hindrance effect” wherein the ORR active Fe centers in FeNC remain inaccessible to larger anions such as phosphate when the Fe sites are present deeper inside the pores of a carbon support with high porosity. However, FeNC catalyst is poisoned by phosphate anions when synthesized using a carbon support with low porosity. This work helps gain insights into the nature of active sites in FeNC catalysts that will be useful in designing precious-metal free ORR catalysts for intermediate temperature fuel cell technologies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Phosphoric acid pre-treatment to tailor polybenzimidazole membranes for vanadium redox flow batteries

We repot vanadium redox flow batteries (VRFBs) use ion-selective membranes for transporting ionic species while separating the positive and negative electrolytes. In this paper, we report phosphoric acid doped polybenzimidazole (PBI) membranes that yield high ionic selectivity and conductivity in VRFBs. The phosphoric acid pre-treatment swells the PBI matrix irreversibly and increases its sulfuric acid doping in VRFB electrolytes. The pre-treated membranes show comparable area resistance with Nafion-212 with better selectivity towards vanadium ions. A low resistance was obtained with a reduced membrane thickness, which can reduce the overall cost of materials. The VRFB using an optimized phosphoric acid pre-treated PBI membrane demonstrates coulombic, voltage, and energy efficiencies of 99.7, 90.3, and 90.0%, respectively, at 40 mA cm -2 while achieving ~40% higher discharge capacity compared to Nafion-212. Furthermore, the VRFB cell shows excellent cycling stability, i.e., only 6.8% or 0.068% per cycle capacity decay for 100 cycles while maintaining coulombic efficiency at >99.9% (98.5% coulombic efficiency for Nafion-212 with a capacity decay of 0.42% per cycle) proving the effectiveness of pre-treatment of phosphoric acid on PBI membranes.

36 MATERIALS SCIENCE↗

Mild pH-decoupling aqueous flow battery with practical pH recovery

Establishing a pH difference between the two electrolytes (pH decoupling) of an aqueous redox flow battery (ARFB) enables cell voltages exceeding the 1.23 V thermodynamic water-splitting window, but acid–base crossover penalizes efficiency and lifetime. Here we employ mildly acidic and mildly alkaline electrolytes to mitigate crossover, achieving high round-trip energy efficiency with open circuit voltage >1.7 V. We implemented an acid–base regeneration system to periodically restore electrolytes to their initial pH values. The combined system exhibited capacity fade rate <0.07% per day, round-trip energy efficiency >85% and approximately 99% Coulombic efficiency during stable operation for over a week. Cost analysis shows that the tolerance of acid–base crossover could be increased if the pH-decoupling ARFB achieved a higher voltage output and lower resistance. Finally, this work demonstrates principles for improving lifespan, rate capability and energy efficiency in high-voltage pH-decoupling ARFBs and pH recovery concepts applicable for pH-decoupling systems.

25 ENERGY STORAGE↗

Interfacial engineering of lithium-polymer batteries with in situ UV cross-linking

Developing promising solid-state Li batteries with capabilities of high current densities have been a major challenge partly due to large interfacial resistance across the electrode/electrolyte interfaces. This work represents an integrated network of self-standing polymer electrolyte and active electrode materials with in situ UV cross-linking. This method provides a uniform morphology of composite polymer electrolyte with low thickness of 20–40 μm. This modification leads to promising cycling results with 85% specific capacity retention in Li||LiFePO4 cell over 100 cycles at high current densities of 170 mA g -1 (~25 μA cm -2 , 1 C). By applying this method, the interfacial resistance decreases as high as seven folds compared to noncross-linked interfaces. The following work introduce a facile and cost-effective method in developing fast-charging self-standing polymer batteries with enhanced electrochemical properties.

25 ENERGY STORAGE↗

Electrolyte Assisted Hydrogen Storage Reactions (Final Technical Report)

The goal of this project is to address critical deficiencies of hydrogen storage systems design based on hydride materials, as originally identified by the DOE Hydrogen Storage Engineering Center of Excellence (HSECoE). Baseline hydrogen storage technology presently relies on compressed gas operating at ~700 bar pressure, which imposes huge demands on fuel delivery, fuel storage and system cost. For onboard storage applications, Type IV composite overwrapped pressure vessels and associated balance-of-plant components are necessary to ensure safe and effective fuel delivery. However, such compressed gas technology falls well-short of volumetric targets even at 700 bar, given the density of gaseous molecular hydrogen is only 40 g·H2/l at ambient temperatures. One alternative is to utilize hydride materials which accommodate hydrogen in atomic form. Certain hydrides can attain volumetric densities that exceed the density of liquid H2 (71 g·H2/l) while also offering advantageous thermodynamic properties. However, such material systems presently rely on solid-state diffusion for hydrogen release, which has a very high activation barrier for atom mobility and, thus, requires impractically-high temperatures for operation. The initial focus of our research effort is to employ and demonstrate an electrolyte system to mediate the diffusion of species at lower temperatures relevant to transportation applications, with the goal of establishing the critical factors necessary to obviate the need for high-temperature release of hydrogen. A parallel goal of this exploratory effort is to determine the effectiveness of modest electrochemical potentials in overcoming any endothermic requirements for hydrogen release in a similar electrolyte-promoted scenario.

08 HYDROGEN↗

Chloride Insertion Enhances the Electrochemical Oxidation of Iron Hydroxide Double-Layer Hydroxide into Oxyhydroxide in Alkaline Iron Batteries

Rechargeable alkaline iron batteries that constitute environmentally benign electrolytes and earth-abundant industrial materials are desirable green solutions for large-scale energy storage. As one of the most abundant metal elements in the earth’s crust, iron (Fe) can satisfy nearly all criteria for low-cost and safe battery electrodes. However, challenges in achieving reversible Fe redox impede their extensive implementation in modern energy supply systems. Here, this study revealed that Cl-anion insertion into Fe(OH) 2 layered double hydroxide (LDH) formed a green rust intermediate phase with the formula [Fe 2 2+ Fe 1 3+ (HO – ) 6 ] + [Cl] – , which assisted a high Fe(OH) 2 /FeOOH conversion reaction (64.7%) and improved cycling stability. This new iron redox chemistry was validated by operando X-ray diffraction, electrochemical testing, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) analysis, scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy (STEM-EDS) mapping, and molecular dynamics (MD) simulations. Our study provides new insight into designing LDH materials for high-capacity alkaline iron batteries.

36 MATERIALS SCIENCE↗

Cost analysis of water recovery systems

Cost and performance data from Gemini, Skylab, and other aerospace and biotechnology programs were analyzed to identify major cost elements required to establish cost estimating relationships for advanced life support subsystems for long range planning in support of earth orbital programs. Cost analysis are presented for five leading water reclamation systems; (1) RITE waste management-water system;(2) reverse osmosis system;(3) multifiltration system;(4) vapor compression system; and(5) closed air evaporation system with electrolytic pretreatment.

Yakut, M. M.↗

Cost analysis of water recovery systems

A methodology was developed to predict the relevant contributions of the more intangible cost elements encountered in the development of flight-qualified hardware based on an extrapolation of past hardware development experience. Major items of costs within water recovery systems were identified and related to physical and/or performance criteria. Cost and performance data from Gemini, Skylab, and other aerospace and biotechnology programs were analyzed to identify major cost elements required to establish cost estimating relationships for advanced water recovery systems. The results of the study are expected to assist NASA in long-range planning and allocation of resources in a cost effective manner in support of earth orbital programs. This report deals with the cost analysis of the five leading water reclamation systems, namely: (1) RITE waste management-water system, (2) reverse osmosis system, (3) multifiltration system, (4) vapor compression system, and (5) closed air evaporation system with electrolytic pretreatment.

Yakut, M. M.↗

Hierarchical screening for Li-based solid electrolytes using fast, interpretable machine-learned potentials

Li-based solid-state electrolyte materials enable safer, all-solid-state batteries but the computational search for candidates with favorable stability and Li-ion conductivity is challenging due to the size of the search space and the cost of evaluating transport properties with ab initio methods. The prohibitive cost of high-throughput screening with DFT has lead to the development of surrogate models using geometric analysis, empirical potentials, and descriptors for ionic transport. Here, I will discuss a hierarchical screening approach for identifying promising materials using a combination of density functional theory, bond-valence methods, and machine learning potentials generated with the Ultra-Fast Force Fields (UF3) framework. We show how the inexpensive bond-valence method can be used to guide the generation of training samples for machine learning, in addition to filtering candidates. Finally, we apply the hierarchical workflow to screen for ionic conductivity across a database of Li-containing compounds.

Materials discovery↗

Hierarchical Screening for Li-Based Solid Electrolytes Using Fast, Interpretable Machine-Learned Potentials

Li-based solid-state electrolyte materials enable safer, all-solid-state batteries but the computational search for candidates with favorable stability and Li-ion conductivity is challenging due to the size of the search space and the cost of evaluating transport properties with ab initio methods. The prohibitive cost of high-throughput screening with DFT has lead to the development of surrogate models using geometric analysis, empirical potentials, and descriptors for ionic transport. Here, I will discuss a hierarchical screening approach for identifying promising materials using a combination of density functional theory, bond-valence methods, and machine learning potentials generated with the Ultra-Fast Force Fields (UF3) framework. We show how the inexpensive bond-valence method can be used to guide the generation of training samples for machine learning, in addition to filtering candidates.

Materials discovery↗

Transparent, High‐Charge Capacity Metal Mesh Electrode for Reversible Metal Electrodeposition Dynamic Windows with Dark‐State Transmission <0.1%

Abstract Dynamic windows allow user control over light and heat flow to save energy and maximize comfort. Reversible metal electrodeposition (RME) dynamic windows can uniquely tint to a color‐neutral privacy state (0.1% visible light transmission). The design parameters of transparent metal mesh counter electrodes for high‐contrast RME dynamic windows: high transparency, charge capacity and surface area with low haze, sheet resistance and cost are discussed, concluding that woven metal meshes meet these design parameters. Electroplated current is measured on an indium tin oxide electrode and two meshes with different wire spacings, showing the meshes’ cylindrical geometry enable them to draw more current per square area. The mesh material composition is analyzed to ensure cycling durability in a CuBi electrolyte by developing a transparent mesh with an inert core (stainless steel, SS), a thin Au coating, and a high charge‐capacity (1.5 C cm −2 ) CuBi outer coating. The study demonstrates that the films maintain a consistent Cu:Bi ratio and optical properties after 250 privacy cycles or 1500 cycles to 10% transmission, showing that the Cu and Bi coating is effective in keeping the films from becoming Cu rich with cycling. Finally, a 100 cm 2 device with excellent uniformity and color neutrality is demonstrated.

Yeang, Andrew L.↗

Design, Synthesis, and Characterization of Polymer Precursors to Li x PON and Li x SiPON Glasses: Materials That Enable All-Solid-State Batteries (ASBs)

LiPON-like glasses that form lithium dendrite impenetrable interfaces between lithium battery components are enabling materials that may replace liquid electrolytes permitting production of all-solid-state batteries (ASBs). Unfortunately, to date, such materials are introduced only via gas-phase deposition. Furthermore, we demonstrate the design and synthesis of easily scaled, lowtemperature, low-cost, solution-processable inorganic polymers containing LiPON/LiSiPON elements. OPCl 3 and hexachlorophosphazene [Cl 2 P=N] 3 provide starting points for elaboration using MNH 2 (M = Li/Na) or (Me 3 Si)NH followed by reaction with controlled amounts of LiNH 2 to produce oligomers/polymers with molecular weights (MWs) ≈1–2 kDa characterized by multinuclear NMR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and matrix-assisted laser desorption/ ionization (MALDI)-time-of-flight (ToF) offering stabilities to 150–200 °C and ceramic yields (800 °C) of 50–60%. 7 Li NMR suggests that precursor-bound Li + dissociates easily, beneficial for electrochemical applications. XPS shows higher N/P ratios (1–3) than via gas-phase methods (<1) correlating N/P ratios, 7 Li shifts, and Li + conductivities. Li 2 SiPHN offers the highest ambient conductivity of 3 × 10 –1 mS cm –1 at 400 °C/2 h/N 2 .

36 MATERIALS SCIENCE↗

Computational Predictions of the Stability of Fluorinated Calcium Aluminate and Borate Salts

Energy storage concepts based on multivalent ions, such as calcium, have great potential to become next-generation batteries due to their low cost and comparable cell voltage and energy density to Li-ion batteries. However, the development of Ca batteries is still hindered by the lack of suitable materials that grant a long cycle life. Specific to electrolyte materials, developing a calcium salt that is chemically stable under ambient conditions and enables reversible electrodeposition of Ca is critical. In this work, we use first-principles calculations to study the intrinsic and reductive stability of twelve Ca salts with fluorinated aluminate and borate anions and analyze the decomposition products formed on the metal anode surface that are critical to early-stage solid electrolyte interphase formation. Here we found anions with significant steric hindrance and a high degree of fluorination are intrinsically less stable and deemed unviable designs for Ca salt. Aluminate salts are generally less reactive with the Ca anode than their borate counterparts, and a high degree of fluorination leads to weaker reductive stability. Calcium fluoride is the most prominent decomposition product on the anode surface, and carbide-like motifs were also found from the decomposition of the designed salts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Metabolic changes observed in astronauts

Results of medical experiments with astronauts reveal rapid loss of volume (2 l) from the legs and a transient early increase in left ventricular volume index. These findings indicate that, during space flight, fluid is redistributed from the legs toward the head. In about 2 days, total body water decreases 2 to 3 percent. Increased levels of plasma renin activity and antidiuretic hormone while blood sodium and plasma volume are reduced suggest that space flight-associated factors are influencing the regulatory systems. In addition to fluid and electrolyte loss, Skylab astronauts lost an estimated 0.3 kg of protein. Endocrine factors, including increased cortisol and thyroxine and decreased insulin, are favorable for protein catabolism. The body appears to adapt to weightlessness at some physiologic cost. Readaptation to earth's gravity at landing becomes another physiologic challenge.

Leach, Carolyn S.↗