Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “achieved”

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 1,279 records · Page 71
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

EVs@Scale Next-Gen Profiles - EV Profile Capture 2023

As part of the U.S. DOE EVs@Scale consortium Next-Gen Profiles (NGP) project, the profile capture of production electric vehicles undergoing high power charging (HPC) is conducted over a wide range of conditions to explore variance and performance. Charge session parameters are collected from both the electric vehicle (EV) and electric vehicle supply equipment (EVSE) at a rate of 10Hz and entered into a time-series database for analysis. These charge profiles are captured under nominal and off-nominal conditions, exploring the impact of battery state of charge (SOC), battery temperature, vehicle condition, smart charge management (SCM), and EVSE limitations. Nominal conditions are defined to be ideal conditions that should transfer the maximum allowable energy in the minimum possible amount of time. Nominal condition profiles are compared across EVs to characterize state-of-the-art EV charging performance against one another. Off-nominal condition profiles are compared against its nominal condition profile counterpart to highlight the variance across less desirable starting conditions within a single EV. Under nominal conditions, most EVs can achieve the original equipment manufacturer (OEM) rated peak-power and charge times. Peak power across EVs has variance due to the vehicle design, battery topology, charging strategy, etc. These 10-100% nominal preconditioned charge profiles across 13 EVs (11 light-duty (LD), 2 heavy-duty (HD)) were used for analysis in power curve analysis, power distribution, SOC and range comparison, thermal impacts of current draw, battery pack size and energy charged, and ramp rates. Power curve analysis show the uniqueness in power vs time curves across all EVs, breaking down the features of a typical profile and where variation is typically seen. Power distribution results showed that over 50% of charge time is spent below 50kW and only 12.1% is spent above 200kW. SOC and range performance yielded different top performing EVs when exploring goals of performance from SOC and range gained after 10-min (EV2) and 20-min (EV8), and time-to-achieve 80% SOC (EV8) and 200 miles of range (EV1). Current draw from 400-volt EVs had a higher thermal impact to cable/connector temperatures when compared to 800-volt EVs, due to a higher current requirement to achieve similar power levels. There was high variance in C rating, a useful metric when comparing the relationship between peak/average charge session power and relative battery pack size, across EVs under test. Ramp rates during initial power transfer were examined, fastest and slowest speeds ranging from 192.5kW/second to 2.6kW/second respectively. A similar analysis of ramp rates was also conducted for OCPP curtailment testing, where EVs underwent a 2-minute 65A curtailment request before returning to full-power charge. Under off-nominal conditions, most EVs experienced variation from the nominal condition profiles. EVs that underwent the full set of NGP defined testing conditions were compared, analysis of which was categorized by 800-volt and 400-volt EVs. It should be noted that the 800-volt EVs had significantly higher peak power ratings than the 400-volt EVs, and thus were more prone to variance. Initial state of charge, battery temperature, and vehicle condition had a considerable impact on peak power levels and charge time for the 800-volt vehicles under test. EVSE limited tests lowered achievable power down to 200kW, greatly impacted 800-volt charging power, and had little to no effect on 400-volt charging power. Adapter testing was performed on a single 400-volt EV, where power and current limitations were found but overall charge time was not significantly impacted. Adapter and boost converter testing was performed on a single 800-volt EV, where both charge power and charge time were greatly impacted. Charge profiles are unique, and comparing such requires analysis that examines starting conditions, vehicle and battery topologies,

Charging↗
DOE OSTI2020

Session 097A - Panel: Accomplishments and Update of the East Tennessee Technology Park in Oak Ridge, TN (1/4) (R1.16a)

This panel was deferred until 2021. The session was designed to highlight and celebrate the accomplishment of Vision 2020 at US DoE's East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Vision 2020 is the overarching strategy and guidance that have formed the foundation of success in closing one of the largest cleanup site in the DOE Complex. The session was supposed to feature representatives from the DOE Oak Ridge Office of Environmental Management (OREM) and its contractor, UCOR, in exploring the partnerships and performance excellence that have made the difference in achieving success. OREM's Vision 2020 is a collaboration with entities that have made a difference in its success: economic developers, workforce developers, the University of Tennessee, and community partners. The vigorous Oak Ridge small business contracting community has also been instrumental in helping achieve success. This session plans to celebrate the entire process, its numerous players, and the spirit of accomplishment as the Oak Ridge community comes to realize the promise of 30 years of continuous cleanup excellence. This session integrated with panel sessions 97B, 97C and 97D. Panelists with presentations: Beyond Cleanup: Achieving Risk Reduction through Partnerships and Performance Excellence (Kenneth Rueter); Strategic Approach to Achieve End States at the East Tennessee Technology Park (Jay Mullis)

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2024

Advanced Fuels Campaign Execution Plan

The Advanced Fuels Campaign (AFC) Execution Plan outlines the strategy, mission, scope, near-term and long-term goals, structure, and organization associated with nuclear fuels and materials research, development, and demonstration activities within the Department of Energy’s (DOE) Nuclear Fuel Cycle and Supply Chain (NFCSC) program. NFCSC has been given responsibility to identify and mature advanced fuel technologies for the DOE using a science-based approach, focused on developing a fundamental understanding of nuclear fuels and materials to drive development of integrated nuclear fuel and materials technology. This science-based approach combines theory, experiments, and multiscale modeling and simulation to achieve a predictive understanding of relevant behaviors ranging from fuel fabrication processes (and their resulting fuel microstructures) through fuel/cladding performance under irradiation (in contrast to more empirical, observation-based approaches frequently used in fuel performance modeling and fuel qualification). The traditional scope of AFC includes the evaluation and development of multiple fuel forms to support two fuel cycle options: once-through and full recycle. The word “fuel” is used generically to include conventional fuels, transmutation targets, and any associated cladding or duct materials. The once-through fuel cycle addresses advanced light water reactor fuels with enhanced performance, extended burnup, and reduced waste generation. In fiscal year (FY) 2012, AFC’s scope expanded to include research, development, and demonstration (RD&D) for light water reactor (LWR) fuels with enhanced accident tolerance. Fuel fabrication activities include the development of innovative methods to enhance process efficiencies, reduce waste, and improve control over as-fabricated fuel microstructural properties to achieve desired in-reactor performance. Using modern modeling and simulation approaches, the objective is to predict fresh fuel properties given the feedstock characteristics and fabrication process parameters. The performance-related activities include small-scale, in-reactor, and out-of-reactor phenomenological testing (distinct from, but synergistic with, integral prototypic testing) and extensive, quantitative characterization (focusing on characterization of fuel and cladding materials at the scale of microstructure) both before and after testing. Larger-scale, prototypic experiments are conducted in concert with phenomenological testing to drive a Fuel Development and Qualification program, incorporating a fundamental understanding of fuel behavior performance characteristics. Then, using the tools developed under the productive science-based approach, fuels will be optimized to meet specific performance requirements, thereby minimizing the need to repeatedly perform large-scale, integral experiments over a wide parametric range as a means of experimental exploration. Two significant initiatives are underway within AFC. First, a gap analysis completed in early FY 2019 identified critical irradiation testing needs that are lacking within the national light water reactor (LWR) fuels testbed since the shutdown of the Halden Reactor in 2018. The identified gaps are for instrumented, prototypic testing of LWR fuels, especially under boiling water reactor conditions, ramp conditions, and conditions leading to fuel failure; these needs exist for supporting current LWR fuels and their possible extension to higher burnups, but are especially urgent relative to near-term development and qualification of accident-tolerant fuels. Recommendations that resulted from the Halden Gap Analysis focused on enhancements at Advanced Test Reactor (ATR) and Transient Reactor Test Facility (TREAT) to fill gaps in testing capabilities relative to these needs. Second, a concerted effort to develop and demonstrate a systematic approach to accelerating the development, testing, and qualification of new fuel systems has been initiated. This is highlighted by a test strategy that combines the considerable advances in multiscale, mechanistic fuel modeling of recent years with a MiniFuel separate effects test program in the High Flux Isotope Reactor (HFIR) and a Fission Accelerated Steady-state Testing (FAST) semi-integral accelerated test program in ATR. This approach is being tested/demonstrated using the metallic fuel system, but if successful it is expected to be extensible to multiple fuel types and diverse applications. This document includes an overview of the NFCSC program, a definition of science-based development of nuclear fuels, near-term goals for Advanced LWR fuels (ALFs), and longer-term goals for Advanced Reactor Fuels (ARFs) RD&D. This includes the activities that will be conducted to achieve success toward the grand challenge, as well as the goals and milestones to be achieved over the next few decades of research and development. Long-term goals are based on the DOE Office of Nuclear Energ

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Development of a Hybrid Single/Two-Phase Capillary-Based Micro-Cooler Using Copper Inverse Opals Wick with Silicon 3D Manifold for High-Heat-Flux Cooling Application: Preprint

Previously, two-phase capillary-based cooling from narrow (200-1,000 micrometer) heater-bridge copper inverse opal (CIO) wicks with heat flux levels exceeding 1,400 watts per square cm with a low superheat of approximately 10 degrees C was demonstrated. Here, we demonstrate the area scaling of the proposed technology to large-area micro-cooler for the high-heat-flux cooling of microprocessors and power electronics. We developed a hybrid single/two-phase micro-cooler that relies on capillary wicking in 25-micrometer-thick CIOs with an open channel silicon 3D-manifold for liquid delivery and vapor extraction, to achieve a high heat flux of approximately 400 watts per square cm over a heated area of 1 square cm. For the range of inlet water (21 degrees C water temperature) flowrates from 5 to 60 mL per min, we achieved total thermal resistances and vapor qualities of 0.68-0.2 square cm Kelvin per watt and 0.55-0.12, respectively. The high heat flux levels are achieved with flowrates that are 10 times smaller than conventional single- or two-phase microchannel cooling technology. The corresponding two-phase thermal resistances are in the range of 0.05 to 0.02 square cm Kelvin per watt with temperature superheat of 8 to 6 degrees C. While the overall performance of the large-area (10 by 10 square millimeter) capillary-based micro-cooler degraded compared to previous demonstration of the technology for a heated area of 5 by 5 square millimeter, preliminary computational fluid dynamics (CFD) modeling indicates that an improved manifold design will be able to achieve comparable performance.

capillary flow↗
DOE OSTI2022

Assessment of Flow-Enhanced Sensors for Actinide Quantification in MSRs

This report serves as the deliverable for Milestone M2RS-22AN0401062 that is part of Work Package RS-22AN040106 (Flow Enhanced Sensors for MSRs – ANL). The goal of this milestone is to assess the capabilities of flow-enhanced electrochemical sensors (FEES) to quantify actinides in molten salt reactors. Flow enhanced electrochemical sensors are a type of electroanalytical sensor that has been developed at Argonne National Laboratory to be installed directly into MSR flow conduits in order to make measurements of the salt composition. These sensors represent a significant improvement in capabilities compared to earlier electroanalytical sensors that instead can only be operated in quiescent conditions. To support this work, Argonne constructed a molten salt flow system to serve as a testbed for the development of safeguards and process monitoring-relevant sensors in challenging molten salt flow conditions. Through extensive flow testing using UCl3-bearing salts, Argonne has been able to show that the FEES are able to make good measurements of salt composition. Concentration measurements with a mean absolute error of 0.09 wt% have been achieved for representative fuel salt mixtures across a range of UCl3 loadings. Repeatability was also good, with the relative standard deviation from repeated measurements being less than 1.0%. These sensors have also been shown to be able to measure the flow rate of the salt within the flow system’s transfer line. Although the accuracy of the sensors has been good, the sensors have thus far not been able to achieve performance good enough to satisfy the nuclear material accountancy requirements in 10 CFR 74. To do so, accuracy levels of 0.1% must be achieved; the FEES when operated in Argonne’s flow system have so far only been able to achieve relative errors of approximately 5.0%. Much of the error that has been observed at this stage is due to challenges in maintaining a stable salt composition in the molten salt flow system, and it is not believed that there are any inherent flaws in the sensor design. Nonetheless, the high degree of accuracy required by 10 CFR 74 represents a significant challenge, and further design evolution and integration of the sensors into multimodal sensing frameworks will likely be needed to push the measurement accuracy to the needed level.

Moore, Colin E.↗
DOE OSTI2025

Optimizing Insulation Design for Transformers in Medium Voltage Power Conversion Systems

Medium-frequency transformers (MFTs) play a crucial role in medium-voltage (MV) solidstate transformer (SST) systems, particularly in extreme fast charging applications. Achieving partial discharge (PD)-free operation while maintaining high power density is a significant challenge due to the high electric field (E-field) stresses inherent in MV applications. This dissertation focuses on the insulation design and optimization of MFTs used in both the main power electronics circuits and auxiliary power supplies. The study begins with an overview of insulation testing methodologies, including high potential tests, basic insulation level tests, and PD tests, which are critical for evaluating MFT insulation reliability. Given the importance of PD-free operation for long-term reliability, particular emphasis is placed on understanding PD mechanisms, including void, corona, and surface discharge, and their mitigation strategies. A high voltage isolated auxiliary power supply is then introduced, utilizing a gapped transformer encapsulated in silicone gel. This design achieves PD-free insulation up to 18 kV RMS while maintaining low coupling capacitance to minimize common-mode current. The proposed solution ensures reliable operation in MV environments and offers a scalable approach for auxiliary power in cascaded SST architectures. To improve MFT insulation in main power conversion circuits, a novel structure is developed using polypropylene sheets and potting compounds to create a void-free air gap, effectively mitigating E-field intensity. A prototype transformer with this insulation structure is built and achieves PD-free operation up to 30 kV RMS. This design is experimentally validated in a resonant converter operating at 46 kW, demonstrating its feasibility for MV SST applications. Further optimization is implemented to enhance MFT performance for dual-active-bridge(DAB) converters by integrating a semiconductive shielding layer within the insulation structure. This shielding layer improves the magnetic coupling coefficient while effectively confining the E-field within high insulation materials, thereby reducing eddy current losses. The optimized MFT achieves PD-free operation at 12.6 kV RMS and is successfully tested in a DAB converter operating at 43 kW, which meets the insulation requirements for a 13.2 kV SST system. This dissertation advances MFT insulation design by introducing and experimentally validating novel approaches that improve high voltage insulation while optimizing magnetic coupling and manufacturability. The proposed insulation structures enable PD-free operation while minimizing insulation material usage and simplifying assembly, making them ideal for high power, high voltage applications.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Droop-Free Distributed Control for AC Microgrids

In this chapter, droop-free distributed control for AC microgrids is discussed. The hierarchical structure of microgrid control is first introduced. Secondary level controls both with and without droop are discussed. Then two droop-free distributed controls are presented: one achieves average voltage regulation and perfect power sharing, and the other one achieves average voltage regulation, voltage variance regulation, and relaxed reactive power sharing. For the latter droop-free control, the relaxed reactive power sharing is achieved through a special distributed generator (DG) that will not participate in reactive power sharing.

Mohiuddin, Sheik Mohammad↗
DOE OSTI2022

Vapor–Fed Electrolyzers for Carbon Dioxide Reduction Using Tandem Electrocatalysts: Cuprous Oxide Coupled with Nickel–Coordinated Nitrogen–Doped Carbon

We report ethylene is particularly attractive due to its major importance as a feedstock for various applications including the polymer industry. As such, catalyst and electrolyzer developments are crucial to achieve industrially relevant ethylene production and efficiency levels. In this work, a tandem electrocatalyst composed of copper nanocubes and nickel-coordinated nitrogen-doped carbon (NiNC) is presented, which is integrated into gas diffusion electrodes (GDEs) for direct conversion of vapor-fed CO 2 into ethylene. Evaluation of tandem GDEs in the vapor-fed flow electrolyzer shows significantly increased ethylene selectivity in terms of faradaic efficiency and C 2 H 4 /CO ratio compared to a non-tandem copper GDE. The enhancements are attributed to the increased local CO availability near the copper surface via effective CO 2 to CO conversion on neighboring NiNC. The experimental results are validated by 3D resolved continuum simulations, which show increased flux of higher-order prod-ucts with the added CO flux from NiNC. The practical viability of Cu/NiNC catalyst is further evaluated in a membrane electrode assembly electrolyzer, achieving 40% FE toward ethylene at 150 mA cm -2 and 3.2 V. These find-ings highlight the high selectivity and formation rate of ethylene achieved by successful device integration of the Cu/NiNC catalyst, demonstrating the potential for implementation in large-scale sustainable CO 2 electrolyzers.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Ultra-Fast Non-Volatile Resistive Switching Devices with Over 512 Distinct and Stable Levels for Memory and Neuromorphic Computing

Low-current multilevel programmability with inherent non-volatility and high stability of resistance states is required for both multi-bit memory storage and deep learning accelerators but is difficult to achieve. Here, in a resistive switching system, this work realizes >512 (>9 bits) distinct non-volatile conductance levels with stable retention for each state with current levels down to the nanoampere range, highly promising for potential integration with small processing nodes with ultra-low power consumption requirements. This is achieved by demonstrating a new thin film design concept that encompasses three key features: an ultra-thin epitaxial oxygen ionic switching layer that provides a tunable energy barrier at the bottom electrode, an overcoat amorphous layer that acts as an ion migration barrier for stable state retention, and a partial conductive filament as a localized electronic transport channel to the epitaxial switching layer. A large dynamic resistance range of up to seven orders of magnitude is achieved with reset-free transitions among intermediate states, and programmability is demonstrated with ultra-fast (20 ns) pulses. Artificial neural network (ANN) simulations, based on the experimental performance and its non-idealities, demonstrate close-to-ideal inference accuracies for various Modified National Institute of Standards and Technology (MNIST) data sets.

36 MATERIALS SCIENCE↗
DOE OSTI2022

All‐Printed Ultrahigh‐Responsivity MoS 2 Nanosheet Photodetectors Enabled by Megasonic Exfoliation

Abstract Printed 2D materials, derived from solution‐processed inks, offer scalable and cost‐effective routes to mechanically flexible optoelectronics. With micrometer‐scale control and broad processing latitude, aerosol‐jet printing (AJP) is of particular interest for all‐printed circuits and systems. Here, AJP is utilized to achieve ultrahigh‐responsivity photodetectors consisting of well‐aligned, percolating networks of semiconducting MoS 2 nanosheets and graphene electrodes on flexible polyimide substrates. Ultrathin (≈1.2 nm thick) and high‐aspect‐ratio (≈1 μm lateral size) MoS 2 nanosheets are obtained by electrochemical intercalation followed by megasonic atomization during AJP, which not only aerosolizes the inks but also further exfoliates the nanosheets. The incorporation of the high‐boiling‐point solvent terpineol into the MoS 2 ink is critical for achieving a highly aligned and flat thin‐film morphology following AJP as confirmed by grazing‐incidence wide‐angle X‐ray scattering and atomic force microscopy. Following AJP, curing is achieved with photonic annealing, which yields quasi‐ohmic contacts and photoactive channels with responsivities exceeding 10 3 A W −1 that outperform previously reported all‐printed visible‐light photodetectors by over three orders of magnitude. Megasonic exfoliation coupled with properly designed AJP ink formulations enables the superlative optoelectronic properties of ultrathin MoS 2 nanosheets to be preserved and exploited for the scalable additive manufacturing of mechanically flexible optoelectronics.

2D materials↗
DOE OSTI2023

Multi–Resonant Mie Resonator Arrays for Broadband Light Trapping in Ultrathin c–Si Solar Cells

Effective photon management is critical to realize high power conversion efficiencies for thin crystalline silicon (c–Si) solar cells. Standard few–100–µm–thick bulk cells achieve light trapping with macroscopic surface textures covered by thin, continuous antireflection coatings. Such sizeable textures are challenging to implement on ultrathin cells. Here, it is illustrated how nanoscale Mie–resonator–arrays with a bimodal size distribution support multiple resonances that can work in concert to achieve simultaneous antireflection and light–trapping across the broad solar spectrum. The effectiveness of these light–trapping antireflection coatings is experimentally demonstrated on a 2.8 µm–thick c–Si solar cell. The measured short–circuit current and corresponding power conversion efficiency are notably improved, achieving efficiencies as high as 11.2%. Measurements of the saturation current density on completed cells indicate that thermal oxides can effectively limit surface recombination. Finally, the presented design principles are applicable to a wide range of solar cells.

14 SOLAR ENERGY↗
DOE OSTI2023

Two‐Color Amplified Spontaneous Emission from Auger‐Suppressed Quantum Dots in Liquids

Abstract Colloidal quantum‐dot (QD) lasing is normally achieved in close‐packed solid‐state films, as a high QD volume fraction is required for stimulated emission to outcompete fast Auger decay of optical‐gain‐active multiexciton states. Here a new type of liquid optical‐gain medium is demonstrated, in which compact compositionally‐graded QDs (ccg‐QDs) that feature strong suppression of Auger decay are liquefied using a small amount of solvent. Transient absorption measurements of ccg‐QD liquid suspensions reveal broad‐band optical gain spanning a wide spectral range from 560 (green) to 675 nm (red). The gain magnitude is sufficient to realize a two‐color amplified spontaneous emission (ASE) at 637 and 594 nm due to the band‐edge (1S) and the excited‐state (1P) transition, respectively. Importantly, the ASE regime is achieved using quasicontinuous excitation with nanosecond pulses. Furthermore, the ASE is highly stable under prolonged excitation, which stands in contrast to traditional dyes that exhibit strong degradation under identical excitation conditions. These observations point toward a considerable potential of high‐density ccg‐QD suspensions as liquid, dye‐like optical gain media that feature readily achievable spectral tunability and stable operation under intense photoexcitation.

Li, Xueyang↗
DOE OSTI2024

Fast Kinetics Design for Solid‐State Battery Device

Abstract Fast kinetics of solid‐state batteries at the device level is not adequately explored to achieve fast charging and discharging. In this work, a leap forward is achieved for fast kinetics in full cells with high cathode loading and areal capacity. This kinetic improvement is achieved by designing a hierarchical structure of electrode composites. In the cathode, the authors’ design enables high areal capacities above 3 mAh cm −2 to be stably cycled at high current densities of ≈13–40 mA cm −2 , yielding a C‐rate from 5 to 10 C. In the anode, the authors’ design breaks the common rule of the negative correlation between critical C‐rate and the discharge voltage that is observed in most other anodes. The overall design enables the fast cycling of such batteries for over 4000 cycles at room temperature and 5 C charge‐rate. The design principles unveiled by this work help to understand critical kinetic processes in battery devices that limit the fast cycling at high cathode loading and speed up the design of high‐performance solid‐state batteries.

Wang, Yichao↗
DOE OSTI2025

Operando Neutron Imaging of Lithium Flux and Gradient Cathode Design for Enhanced Kinetics in High‐Loading All‐Solid‐State Li─S Batteries

All-solid-state Li–sulfur batteries (ASSLSBs) are considered promising candidates for next-generation energy storage owing to their inherent safety, high energy density, and abundant sulfur resources. However, slow redox kinetics greatly limit sulfur utilization during solid-solid sulfur reactions, leading to significant challenges to achieve efficient performance in high-mass-loading ASSLSBs. Here, operando neutron image is employed to directly visualize, for the first time, that sluggish Li + transport kinetics and the uneven distribution of Li + during cathodic reactions are critical factors limiting sulfur conversion. To address this issue, gradient cathode architectures comprising three and five layers are designed, in which catholyte concentrations are strategically varied to optimize Li-ion flux and enhance ionic conductivity of the whole composite cathode electrode. Operando neutron imaging distinctly visualizes and confirms that three-layer gradient approach significantly enhances Li-ion mobility, resulting in more uniform redox reactions and greatly improved sulfur utilization compared to traditional non-gradient structures. Consequently, the three-layer gradient cathode achieves superior rate performance and reduced electrode polarization at high sulfur mass loadings of 4.5 and 6.0 mg cm −2 . Furthermore, the applicability and scalability of this design are demonstrated in a five-layer gradient cathode architecture, achieving an impressive discharge specific capacity increase from 656 mAh g −1 (three-layer gradient) to 1232 mAh g −1 at 1/20 C for ultra-high sulfur loading of 7.5 mg cm −2 . In conclusion, this innovative gradient cathode design offers substantial advancements in understanding and overcoming Li-ion transport limitations, paving the way toward practical, high-energy-density ASSLSBs.

25 ENERGY STORAGE↗
DOE OSTI2026

Active Learning‐Driven Inkless Additive Nanomanufacturing for Printed Electronics

Inkless additive nanomanufacturing for printed electronics promises broad material and substrate versatility, yet the high-dimensional print parameter space makes tuning print parameters time-intensive. We present a Bayesian optimization study that constructs a digital twin from printed-silver data to benchmark surrogate models, acquisition functions, and batch sizes head-to-head to achieve user-specified target resistance. Tested surrogate models included Gaussian process, random forest, and Bayesian neural network surrogates with expected improvement and confidence bound acquisition functions. In total, we evaluate 48 unique model configurations alongside a random sampling baseline for comparison. For printed silver, the Bayesian neural network with a batch size of one achieved the lowest average cumulative regret, approximately four times more efficient on average than random sampling. To balance performance and substrate space, a random forest model with expected improvement and a batch size of four was chosen as the model for validation testing. Applying this chosen configuration to copper with an additional print parameter, the model achieved a resistance within 0.15 Ω of a 1 Ω target in fewer than 30 printed lines across five validation sets. Altogether, the workflow yields a tuned and validated model that efficiently guides experiments toward the target while simultaneously learning the parameter space.

Bevel, Colton [Auburn University, AL (United State↗
DOE OSTI2023

Organometal Halide Perovskite‐Based Photoelectrochemical Module Systems for Scalable Unassisted Solar Water Splitting

Despite achievements in the remarkable photoelectrochemical (PEC) performance of photoelectrodes based on organometal halide perovskites (OHPs), the scaling up of small-scale OHP-based PEC systems to large-scale systems remains a great challenge for their practical application in solar water splitting. Significant resistive losses and intrinsic defects are major obstacles to the scaling up of OHP-based PEC systems, leading to the PEC performance degradation of large-scale OHP photoelectrodes. Herein, a scalable design of the OHP-based PEC systems by modularization of the optimized OHP photoelectrodes exhibiting a high solar-to-hydrogen conversion efficiency of 10.4% is suggested. As a proof-of-concept, the OHP-based PEC module achieves an optimal PEC performance by avoiding major obstacles in the scaling up of the OHP photoelectrodes. The constructed OHP module is composed of a total of 16 OHP photoelectrodes, and a photocurrent of 11.52 mA is achieved under natural sunlight without external bias. The successful operation of unassisted solar water splitting using the OHP module without external bias can provide insights into the design of scalable OHP-based PEC systems for future practical application and commercialization.

14 SOLAR ENERGY↗
DOE OSTI2025

Technoeconomic Insights into Metal Hydrides for Stationary Hydrogen Storage

Abstract Metal hydrides (MHs) are promising candidates for storing hydrogen at ambient conditions at high volumetric energy densities. Recent developments suggest hydride‐based systems can cycle and operate at favorable pressures and temperatures that work well with fuel cells used in stationary power applications. In this study, we present a comprehensive design and cost analysis of MH‐based long duration hydrogen storage facilities for a variety of power end users (0 to 20 megawatts (MW) supplied over 0 to 100 hours), to offer insights on technical targets for material development and operation strategies. Our findings indicate that hydride‐based storage systems hold significant size advantage in physical footprint, requiring up to 65% less land than 170‐bar compressed gas storage. Metal hydride systems can be cost competitive with 350‐bar compressed gas systems, with TiFe 0.85 Mn 0.05 achieving $0.45/kWh and complex MH Mg(NH 2 ) 2 ‐2.1LiH‐0.1KH achieving $0.38/kWh. Extending charging times and increasing operating cycles significantly reduce levelized cost of storage, especially for complex MHs. Key strategies to further enhance the competitiveness of MHs include leveraging waste heat from fuel cells, reducing use of critical minerals, and achieving MH production costs of US$10/kg.

08 HYDROGEN↗