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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Mitigating the Effects of Au-Al Intermetallic Compounds Due to High-Temperature Processing of Surface-Electrode Ion Traps

Stringent physical requirements need to be met for the high-performing surface-electrode ion traps used in quantum computing and timekeeping. In particular, these traps must survive a high-temperature environment for vacuum chamber preparation and support high RF voltage on closely spaced electrodes. Due to the use of gold wire bonds on aluminum pads, intermetallic growth can lead to wire bond failure via breakage or high resistance, limiting the lifetime of a trap assembly to a single multiday bake at 200 ° C. Using traditional thick metal stacks to prevent intermetallic growth, however, can result in trap failure due to RF breakdown events. Through high-temperature experiments, we conclude that an ideal metal stack for ion traps is Ti/Pt/Au (20/100/250 nm), which allows for a cumulative bakeable time of roughly 86 days without compromising the trap voltage performance. This increase in the bakeable lifetime of ion traps will remove the need to discard otherwise functional ion traps when vacuum hardware is upgraded, which will greatly benefit ion trap experiments.

Haltli, Raymond A.↗
DOE OSTI2025

Laser ablation of high-loading Li-ion battery electrodes improves accessible capacity and cycle life for Behind-the-Meter Storage

Adoption of Behind-the-Meter Storage (BTMS) requires design of batteries that enable high safety, long cycle life, and low cost at the system level. Pairing Li 4 Ti 5 O 12 (LTO) with LiMn 2 O 4 (LMO) achieves targets related to safety and cycle life, but these materials' low energy densities contribute to higher cost at the system scale. Increasing electrode loading is a simple approach to improve energy density, but comes with a trade-off in electrode utilization due to long, tortuous Li + diffusion pathways. Here, laser ablation is used to microstructure (pattern) high-loading electrodes to enhance electrode performance through improved Li + diffusion pathways. Four cell types, comprising combinations of standard or patterned anode and cathode, were prepared to evaluate the effects of laser ablation at each electrode. A rate test shows that patterning electrodes enhances active material utilization at ≳1C rates. Patterning the cathode yields the most benefit, as cells with a patterned cathode demonstrate a ~20% higher accessible capacity than those without at 1.4C. Additionally, 1C capacity retention of cells with patterned cathode (91% through 3000 cycles) is significantly improved over cells with only the anode patterned (64%) and non-patterned electrodes (50%). Characterization of post-mortem cells before and after refreshing their electrolyte suggests that 1C capacity retention is improved by mitigation of electrode "dry-out". We hypothesize that the microstructure acts as a reservoir of additional electrolyte, or a path for gas to escape, so that active material remains wetted throughout long-term cycling, and/or the microstructure may reduce localized, gas-forming overpotentials in the high-loading electrode.

25 ENERGY STORAGE↗
DOE OSTI2026

Electro-chemo-mechanically Driven Ni Exsolution from (Pr,Ce,Ni)O 2−δ : Controlled Nucleation Density and Enhanced Electrode Kinetics

In situ exsolution of metal nanoparticles is a promising strategy to prepare electrocatalysts with enhanced activity and resistance to agglomeration for efficient chemical transformations and energy conversion. Achieving a high nucleation density of nanoparticles under mild conditions and understanding how to tailor the process is important for performance of these electrodes in electrochemical cells. In this work, we demonstrate facile exsolution of Ni nanoparticles using fluorite-structured (Pr,Ce)O 2−δ as the support oxide, driven by electrochemical potential and aided by the metastability of Ni in the solid solution (elastic driving force). We prepare single-phase oriented thin films of (Pr,Ce,Ni)O 2−δ (NPCO) on (Zr,Y)O 2−δ (YSZ) substrates by pulsed laser deposition. With the aid of a high-throughput electrochemical cell that provides a lateral gradient in Nernst voltage, we apply in situ near-ambient pressure synchrotron X-ray photoelectron spectroscopy and ex situ atomic force microscopy to investigate the impact of electrochemical potential on Ni nucleation density. We find that metallic Ni can be successfully exsolved at 550 °C upon cathodic biasing in 20 mTorr O 2 , and its nucleation density increases with increasing electrochemical driving force/decreasing oxygen chemical potential. We further evaluate the electrochemical performance under highly reducing (fuel electrode) conditions by electrochemical impedance spectroscopy. With the exsolved Ni nanoparticles, the surface exchange coefficient of the NPCO is found to be ∼4× higher than for PCO without exsolution. This work confirms mixed conducting fluorites as beneficial host lattices for facile transition-metal exsolution and suggests the possibility for constructing an all ceria-based electrochemical cell with PCO serving as both the cathode and the anode.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Surface treatment for lithium battery electrode materials

Electrode materials for electrochemical cells and batteries and methods of producing such materials are disclosed herein. A method of preparing an active lithium metal oxide material suitable for use in an electrode for a lithium electrochemical cell comprises the steps of: (a) contacting the lithium metal oxide material with an aqueous acidic solution containing one or more metal cations; and (b) heating the so-contacted lithium metal oxide from step (a) to dryness at a temperature below 200° C. The metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of an alkaline earth metal ion, a transition metal ion, and a main group metal ion.

25 ENERGY STORAGE↗
DOE OSTI2021

Protective coating for lithium-containing electrode and methods of making the same

A lithium-containing electrode with a protective coating and lithium-containing electrochemical cells including the same are provided herein. The protective coating has a first layer including a first fluoropolymeric matrix and Li—F compounds and a second layer including a second fluoropolymeric matrix. Methods of preparing the protective coating on the lithium-containing electrode by applying a first fluoropolymer and/or a first fluoropolymer precursor and a second fluoropolymer and/or a second fluoropolymer precursor are also provided herein.

Xiao, Xingcheng↗
DOE OSTI2024

Freeze Tape Casting Electrode with Bilayered Architecture for High-Performance Lithium-Ion Batteries

A facile freeze tape casting (FTC) strategy is utilized to prepare bilayered 4 mAh cm –2 high-loading LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathodes. The bottom layer is a conventional nonaqueous electrode, which has a dense structure for high-energy purposes. Further, the top layer is prepared by the proposed FTC, exhibiting a porous feature for high-power requirement. With the assistance of FTC, the bilayered electrodes successfully deliver enhanced rate and cyclic performance due to the improved lithium-ion diffusion kinetics and pathways. Therefore, the proposed FTC strategy and its delivered electrodes are promising for energy- and power-density lithium-ion batteries, potentially enlightening the research and development of lithium-ion battery manufacturing.

25 ENERGY STORAGE↗
DOE OSTI2023

Multielectrode electrochemical cell for in situ structural characterization of amorphous thin-film catalysts using high-energy X-ray scattering

A multielectrode-based electrochemical cell allows the structural characterization of an amorphous thin-film water oxidation catalyst under various electrochemical potentials using high-energy X-ray scattering and atomic pair distribution function (PDF) techniques. A multielectrode with five electrodes provides a sufficiently low background signal to enable high-energy X-ray scattering (HEXS) measurements and amplifies the extremely low HEXS signals from samples for high-resolution PDF analysis of in situ data from thin-film catalysts. Glassy carbon (GC) creates a relatively low intensity HEXS pattern and is used as a working electrode. Instead of a three-dimensional (3D) porous electrode architecture, the flat geometry of the electrode enables various deposition techniques to be used for the preparation of a highly conductive metal oxide layer. PDF analysis demonstrates high spatial resolution for a 230 nm thick amorphous iridium oxide film deposited on two roughened 60 µm thick GC electrodes. The PDF analysis resolves the domain size and distinguishes changes in fine structure which are directly correlated with the structure and function of the catalysts. In conclusion, the results bring the opportunity to analyze the structure of nanometre-scale amorphous thin-film catalysts in an electrolyte-compatible and compact 3D-printed electrochemical cell in a three-electrode configuration.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Elucidating the Role of Ionomer in the Performance of Platinum Group Metal-free Catalyst Layer via in situ Electrochemical Diagnostics

The ionomer content in platinum group metal (PGM)-free polymer electrolyte fuel cell (PEFC) cathode catalyst layer (CCL) plays an important role in the electrode gas transport properties, proton conductivity, and hence, membrane electrode assembly (MEA) performance. In this work, the ionomer content in the CCL is varied, influencing electrode microstructure by altering porosity, tortuosity, as well as ionomer distribution and coverage of the catalyst particles. A novel technique consisting of a H 2 pump, combined with a Pt black sensor layer, is used to measure the bulk mass transport resistance of a series of PGM-free CCL prepared with different ionomer contents. The values for bulk electrode mass transport resistance are contrasted with electrode proton transport resistance in the cathode catalyst layer, establishing a clearly defined trade-off between two key performance limiting phenomena and identifying a need for novel PGM-free electrode fabrication strategies.

25 ENERGY STORAGE↗
DOE OSTI2023

Lead-lead oxide-carbon nanocomposite for energy storage cells and method of preparation

Lead/lead oxide/carbon (“Pb—O—C”) nanocomposite materials are useful as electrode active materials for electrodes in lithium and sodium batteries. A Pb—O—C nanocomposite as described herein comprises Pb and lead oxide nanoparticles homogeneously dispersed in a carbon nanoparticle matrix. In the nanocomposite, the other element or elements (e.g., transition metals, Al, Si, P, Sn, Sb, and Bi) can be alloyed with the Pb nanoparticles, incorporated as a mixed oxide with the lead oxide nanoparticles, or can be present as distinct elemental or oxide nanoparticles within the carbon nanoparticle matrix. In some embodiments, the additional element or elements are present as alloys and mixed oxides with the Pb materials and as distinct elemental and/or oxide nanoparticles. In a preferred embodiment the Pb nanoparticles surface is oxidized to lead oxide thus creating a shell on core nanostructure.

Johnson, Christopher S.↗
DOE OSTI2020

Chemical approaches to artificial photosynthesis: A molecular, dye-sensitized photoanode for O 2 production prepared by layer-by-layer self-assembly

We describe here the preparation of a family of photoanodes for water oxidation that incorporate an electron acceptor–chromophore–catalyst in single molecular assemblies on nano-indium tin oxide (nanoITO) electrodes on fluorine-doped tin oxide (FTO). The assemblies were prepared by using a layer-by-layer, Atomic Layer Deposition (ALD), self-assembly approach. In the procedure, addition of an electron acceptor viologen derivative followed by a Ru II (bpy) chromophore and a pyridyl derivative of the water oxidation catalyst [Ru(bda) (L) 2 ] (bda = 2,2'-bipyridine-6,6'-dicarboxylate) 2 , were linked by ALD by addition of the bridge precursors TiO 2 , ZrO 2 , and Al 2 O 3 as the bridging groups giving the assemblies, FTO|nanoITO|–MV 2+ –ALD MO 2 –RuP2 2+ –ALD M'O 2 –WOC. In a series of devices, the most efficient gave water oxidation with an incident photon to current efficiency of 2.2% at 440 nm. Transient nanosecond absorption measurements on the assemblies demonstrated that the slow step in the intra-assembly electron transfer is the electron transfer from the chromophore through the viologen bridge to the nanoITO electrode.

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

An Ultrafast, Durable, and High-Loading Polymer Anode for Aqueous Zinc-Ion Batteries and Supercapacitors

Zn metal has shown promise as an anode material for grid-level energy storage, yet is challenged by dendritic growth and low Coulombic efficiency. Herein, an ultrafast, stable, and high-loading polymer anode for aqueous Zn-ion batteries and capacitors (ZIBs and ZICs) is developed by engineering both the electrode and electrolyte. The anode polymer is rationally prepared to have a suitable electronic structure and a large pi-conjugated structure, whereas the electrolyte is manufactured based on the superiority of triflate anions over sulfate anions, as analyzed and confirmed via experiments and simulations. This dual engineering results in an optimal polymer anode with a low discharge potential, near-theoretical capacity, ultrahigh-loading capability (approximate to 50 mg cm -2 ), ultrafast rate (100 A g -1 ), and ultralong lifespan (one million cycles). Further, its mechanism involves reversible Zn 2+ /proton co-storage at the carbonyl site. When the polymer anode is coupled with cathodes for both ZIB and ZIC applications, the devices demonstrate ultrahigh power densities and ultralong lifespans, far surpassing those of corresponding Zn-metal-based devices.

25 ENERGY STORAGE↗
DOE OSTI2026

Supervisory Control and Data Acquisition for Electrochemical Separation Experimentation

The Python-based program is a laboratory automation tool designed to control and monitor electrochemical systems. The tool was developed for capacitive deionization (CDI) experiments, but it can be used for any system that requires controlled voltage or current segments and multi-parameter monitoring. The program integrates hardware components to run user-defined experimental parameters, providing operational control of a programmable power supply, peristaltic pump, and data acquisition devices. Currently, the program is structured with a workflow that includes an initialization (or pre-run) phase, a main loop, and a post-experiment stabilization (or post-run) phase. The initialization phase prepares and stabilizes the cell, ensuring that the electrodes and solution reach a baseline state before the experiment begins. The main loop consists of multiple voltage segments that repeat, controlling the experiment while recording key parameters such as time, voltage, current, pH, and conductivity. Finally, the post-experiment stabilization phase allows the system to stabilize after the experiment, returning the cell and solution to equilibrium conditions before ending the sequence. The program is designed with four variations, each tailored to different experimental needs. All variations include both the initialization and post-experiment stabilization stages, which run for a set amount of time, voltage, current, and flow rate before and after the main experiment block. The main loop runs for a set number of cycles, as defined by the user input, and each cycle is composed of 2 or 4 segments. The 4 program variations are described as follows: Program 1: The main program includes 2 segments. Each segment is defined to have a set duration, flow rate, voltage, and current. This program measures conductivity, flow rate, voltage, and current. Program 2: The main program expands Program 1 to include 4 segments. Each segment has a specified duration, flow rate, voltage, and current. Like Program 1, it measures conductivity, flow rate, voltage, and current. Program 3: The main program consists of 2 segments, each defined by time, flow rate, voltage, and current. In addition to conductivity, flow rate, voltage, and current, Program 3 collects pH and temperature data through a 4-channel data acquisition device. Program 4: This program independently controls two channels of a multi-channel power supply simultaneously. While conductivity can only be measured for one cell at a time, the dual-channel control makes it possible to operate two cells simultaneously under different voltage/current conditions. The main program includes 2 segments.For each program, all measurements are automatically logged and integrated into a single Excel output file. Data are displayed in numerical format and plotted, both in real time, to track system performance. A key feature of the program is its ability to synchronize all outputs so that every measurement shares a single timestamp, ensuring accurate alignment of voltage, current, pH, conductivity, and pH data.By combining hardware control, real-time monitoring, and unified data collection, this program significantly reduces manual workload and minimizes errors, making it a reliable platform for researchers, engineers, and laboratory technicians conducting CDI experiments, among other electrochemical tests.

Valentino, Lauren [Argonne National Laboratory (AN↗
DOE OSTI2020

Lignin-derived electrochemical energy materials and systems

Electrochemical energy storage systems such as supercapacitors, rechargeable batteries and fuel cells have been proven the most effective technologies for energy conversion, storage, and management at different scales. Although a large number of electrochemical energy technologies have been developed in the past and they will continue to be optimized in terms of cost, lifetime, and performance, there is a substantial growing demand for advanced electrochemical energy systems. To deploy these advanced systems, the electrode and electrolyte materials with higher performance, longer life, and lower cost, must be developed. Lignin is the second most abundant natural polymer after cellulose, a byproduct from emerging cellulosic biorefineries, and a waste product from pulp and paper industries. Numerous researches have successfully demonstrated that lignin from different sources can be used as precursors or feedstocks for preparing high-performance electrochemical energy materials and components such as electrodes, electrolytes, membrane separators, and additives. Moreover, techno-economic analyses indicate that it is possible to prepare cost-effective carbons from lignin at engineering scales, compared to current carbon products. These facts suggest that scalable conversion of lignin into high-value energy materials will offer a promising pathway to not only promote the utilization and valorization of lignin but also boost the development of the advanced electrochemical energy systems. This review presents state of the arts of renewable energy materials derived from various lignin and their applications in electrochemical energy systems with emphasis on supercapacitors, rechargeable batteries, and fuel cells. Meanwhile, this article also aims to carve out the critical barriers for lignin-derived high-performance materials for energy applications, intending to identify viable approaches for synthesis of sustainable new energy materials.

09 BIOMASS FUELS↗
DOE OSTI2023

Hybrid Mesoporous Carbon/Copper Ferrite Electrode for Asymmetric Supercapacitors

Asymmetric supercapacitors (ASCs) with two dissimilar electrodes are known to exhibit relatively moderate energy and power densities. If electrodes derived from earth-abundant materials or renewable resources such as lignocellulosic biomass (LCB) are used for fabrication, energy storage systems are expected to become less expensive and more sustainable. Hybrid electrode materials have advantages such as higher surface area, better chemical stability, and superior energy density. This study reports on the synthesis of a novel hybrid electrode material containing porous carbon (POC) and copper ferrite, which is designated as POC@Cu-ferrite, and its electrochemical performance in ASC configuration. Corn stover derived hydrochar is utilized for the sol–gel synthesis of POC@Cu-ferrite hybrid material using earth-abundant Cu and Fe-based precursors. This material is characterized using X-ray diffraction (XRD), Raman spectroscopy, Brunauer–Emmett–Teller (BET) surface area analyzer, and scanning and transmission electron microscopy (SEM/TEM). As-synthesized Cu-ferrite is found to contain 89.2% CuFe 2 O 4 and 10.8% Fe 2 O 3 , whereas other phases such as Fe 3 O 4 , CuFeO 2 , and CuO are observed for the POC@Cu-ferrite. BET-specific surface area (SSA) and pore volume of POC@Cu-ferrite are observed as 1068 m 2 /g and 0.72 cm 3 /g, respectively. POC@Cu-ferrite hybrid electrode is used with POC opposite electrode to fabricate ASC, which is tested using Gamry G-300 potentiostat/galvanostat/ZRA to obtain cyclic voltammetry (CV) profiles and galvanostatic charge–discharge (GCD) plots. ASC is also prepared using Cu-ferrite and POC materials and its specific capacitance and stability are compared with ASCs prepared with POC@Cu-ferrite and POC or graphene nanoplatelets (GNPs) electrodes. POC@Cu-ferrite hybrid electrode is found to be superior with a 2-fold higher capacitance and significant electrochemical stability over 100 GCD cycles as compared to the Cu-ferrite electrode.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Preparation of ultrathin sputtered gold films on palladium as efficient oxygen reduction electro-catalysts

Herein, we present the preparation of ultrathin gold (Au) films on different M (M = Pd, Pt, Rh, Ir, and Ru) electrodes (Au/M) using magnetron sputtering deposition for oxygen reduction reaction (ORR). The ORR electro-catalytic activities of prepared Au/M catalysts increase as follows: Au/Ru < Au/Ir < Au/Rh < Au/Pt < Au/Pd. Accordingly, the oxygen reduction catalytic behaviors of the Au-modified palladium (Au/Pd) thin films with various Au thicknesses (0.16, 0.24, 0.5, and 1 nm) are investigated in acidic environments. It is found that Au modifications can promote oxygen reduction performances due to the development of more catalytic active sites on the Pd catalyst through the existence of Au atoms. Noticeably, Au/Pd samples exhibit a connection in oxygen reduction ability as a function of Au thickness, with the ultrathin 0.16 nm Au/Pd being the most active ORR catalyst. Significantly, the 0.16 nm Au/Pd material demonstrates superior stability after 1000 potential cycles compared with the 0.16 nm Pt/Pd owing to the influence of Au coating and structurally stable surfaces. Therefore, surface modification with the deposition of Au films on Pd represents a favorable technique to boost both the ORR capability and stability of the electro-catalysts.

Magnetron sputtering↗
DOE OSTI2024

Engineering of a Coupled Nanocomposite as a High-Performance Protonic Ceramic Fuel Cell Cathode

The lack of high-performance cathode catalysts is a salient issue that bedeviled the commercialization of protonic ceramic fuel cells (PCFCs). Here, in this work, we report a remarkable electrocatalytic activity and stability enhancement of cathode electrodes by engineering a coupled nanocomposite. The as-prepared Pr 0.3 (Ba 0.5 Sr 0.5 ) 0.7 Co 0.8 Fe 0.2 O 3−δ nanocomposite possesses a bulk cubic phase on which homogeneous and intimate orthorhombic PrCo 0.5 Fe 0.5 O 3−δ nanoparticles are uniformly decorated. X-ray diffraction and Raman spectroscopy reveal the excellent thermal stability of the nanocomposite. It achieves a high peak power density of 1.02 W cm –2 based on protonic electrolytes at 600 °C. No noticeable structural degradation is observed over ∼210 h at 550 °C according to scanning electron microscopy analysis. This work demonstrates an effective strategy to boost the performance of perovskite oxides for PCFCs via nanocomposite engineering. It may apply to other catalyst designs and discoveries, such as for batteries, electrolyzers, and membrane reactors.

08 - HYDROGEN↗
DOE OSTI2020

Direct Measure of Electrode Spatial Heterogeneity: Influence of Processing Conditions on Anode Architecture and Performance

The spatial (in)homogeneity of aqueous processed silicon electrodes using standard poly(acrylic acid)-based binders and slurry preparation conditions is demonstrated in this work. X-ray nanotomography shows segregation of materials into submicron-thick layers depending on the mixing method and starting binder molecular weights. Using a dispersant, or in situ production of dispersant from the cleavage of the binder into smaller molecular weight species, increases the resulting lateral homogeneity while drastically decreasing the vertical homogeneity as a result of sedimentation and separation due to gravitational forces. This data explains some of the variability in the literature with respect to silicon electrode performance and demonstrates two potential ways to improve slurry-based electrode fabrications.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Electrochemistry-Induced Direct Deposition of Nanoscale Thin Zeolitic Imidazolate Framework-8 Films on Insulator Substrates

Electrochemical approaches have been explored as controlled means to prepare thin films of metal–organic frameworks (MOFs) on electrodes but have rarely been used to form insulator films on insulator surfaces. Herein, we report an electrochemistry-based approach to direct deposition of a thin film of zeolitic imidazolate framework-8 (ZIF-8) onto an insulator surface. The film deposition was induced by a cathodic reaction at an electrode that was placed above the insulator with a separation of ≈100 μm in a methanol solution containing ZnCl 2 and 2-methylimidizole. The effects of the electrode and insulator material, applied potential, electrode–substrate distance, deposition time, and the number of deposition cycles were systematically investigated to gain insight into the deposition mechanism. The results of these measurements were consistent with a hypothesized mechanism involving cathodic base generation at the working electrode for ligand deprotonation, formation of intermediate species, their diffusion toward the substrate, and the formation of ZIF-8 on the substrate. Interestingly, the size, shape, and position of the film on the substrate replicated those of the working electrode, showing the applicability of this approach to the patterned deposition of a ZIF-8 film. In addition, film thickness could be easily controlled in the range of tens to hundreds of nanometers by adjusting the potential application conditions. Furthermore, this electrochemistry-induced method will provide a simple means for the patterned formation of a MOF film of controlled thickness on an insulator without metal precoating and thus will open the possibility of designing unique devices for various applications including chemical sensing and separations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗