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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Heterogeneous doping via nanoscale coating impacts the mechanics of Li intrusion in brittle solid electrolytes

Lithium dendrite intrusion in solid-state batteries limits fast charging and causes short-circuiting, yet the underlying regulating mechanisms are not well-understood. Here, in this work, we discover that heterogeneous Ag + doping dramatically affects lithium intrusion into Li 6.6 La 3 Zr 1.6 Ta 0.4 O 12 (LLZO), a brittle solid electrolyte. Nanoscale Ag + doping is achieved by thermally annealing a 3-nm-thick metallic coating on LLZO, inducing Ag–Li ion exchange and Ag diffusion into grains and grain boundaries. Density functional theory calculations and experimental characterization show negligible impact on the electronic properties and surface wettability from Ag + incorporation. Mechanically, nanoindentation experiments show a fivefold increase in the mechanical force required to fracture the surface Ag + -doped LLZO, indicating substantial doping-induced surface toughening. Operando microprobe scanning electron microscopy experiments show that the Ag + -doped LLZO surface exhibits improved lithium plating at >250 mA cm −2 and an electroplating diameter that is expanded by over fourfold, even under an extreme indentation stress of 3 GPa. This demonstrates enhanced defect tolerance in LLZO, rather than electronic or adhesion effects. Our study reveals a chemo-mechanical mechanism via surface heterogeneous doping, complementing present bulk design rules to minimize mechanical failures in solid-state batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Unveiling the Stabilities of Nickel–Based Layered Oxide Cathodes at an Identical Degree of Delithiation in Lithium–Based Batteries

Bulk, surface, and interfacial instabilities that impact the cycle and thermal performances are the major challenges with high-energy-density LiNi 1–x–y Mn x Co y O 2 (NMC) cathodes with high nickel contents. It is generally believed that the instabilities and performance losses become exponentially aggravated as the nickel content increases. Disparate from this prevailing belief, it is herein demonstrated that NMC cathodes with higher Ni contents may imply better overall stability than “lower-Ni” cathodes under an identical degree of delithiation (charging) conditions. With two representative cathodes, LiNi 0.8 Mn 0.1 Co 0.1 O 2 and LiNiO 2 , a systematic investigation into their stabilities with control of the degree of delithiation is presented. Electrochemical tests indicate that LiNiO 2 displays better cyclability than LiNi 0.8 Mn 0.1 Co 0.1 O 2 at the same delithiation state. Comprehensive structural and interphase investigations unveil that the inferior cyclability of LiNi 0.8 Mn 0.1 Co 0.1 O 2 predominantly results from aggravated parasitic reactions, and the interphase stability may be more critical than lattice stability in dictating cyclability. Also, LiNiO 2 delivers similar or better thermal behavior than LiNi 0.8 Mn 0.1 Co 0.1 O 2 . Finally, the findings demonstrate a strong correlation of the stability of NMC cathodes to the degree of delithiation state rather than the Ni content itself, highlighting the importance of reassessing the true implications of Ni content and structural and interphasial tuning on the stabilities of NMC cathodes.

25 ENERGY STORAGE↗
DOE OSTI2021

A Cobalt– and Manganese–Free High–Nickel Layered Oxide Cathode for Long–Life, Safer Lithium–Ion Batteries

High-nickel LiNi 1–x–y Mn x Co y O 2 and LiNi 1–x–y Co x Al y O 2 cathodes are receiving growing attention due to the burgeoning demands on high-energy-density lithium-ion batteries. The presence of both cobalt and manganese in them, however, triggers multiple issues, including high cost, high toxicity, rapid surface deterioration, and severe transition-metal dissolution. Herein, a Co- and Mn-free ultrahigh-nickel LiNi 0.93 Al 0.05 Ti 0.01 Mg 0.01 O 2 (NATM) cathode that exhibits 82% capacity retention over 800 deep cycles in full cells, outperforming two representative high-Ni cathodes LiNi 0.94 Co 0.06 O 2 (NC, 52%) and LiNi 0.90 Mn 0.05 Co 0.05 O 2 (NMC, 60%) is presented. It is demonstrated that a titanium-enriched surface along with aluminum and magnesium as the stabilizing ions in NATM not only ameliorates unwanted side reactions with the electrolyte and structural disintegrity, but also mitigates transition-metal dissolution and active lithium loss on the graphite anode. As a result, the graphite anode paired with NATM displays an ultrathin (≈8 nm), monolayer anode-electrolyte interphase architecture after extensive cycling. Furthermore, NATM displays considerably enhanced thermal stability with an elevated exothermic temperature (213 °C for NATM vs 180 and 190 °C for NC and NMC, respectively) and remarkably reduced heat release. This work sheds light on rational compositional design to adopt ultrahigh-Ni cathodes in lithium-based batteries with low cost, long service life, and improved thermal stability.

25 ENERGY STORAGE↗
DOE OSTI2022

Search for new hadronic decays of $h_c$ and observation of $h_c$ → $p\overline{p}η$

A search for the hadronic decays of the $h_c$ meson to the final states $p\overline{p}π^+π^-π^o$, $p\overline{p}η$, and $p\overline{p}π^o$ via the process $\psi$(3686) → $π^oh_c$ is performed using (4.48 ± 0.03) x 10 8 $\psi$(3686) events collected with the BESIII detector. The decay channel $h_c$ → $p\overline{p}η$ is observed for the first time with a significance greater than 5σ and a branching fraction of (6.41 ± 1.74 ± 0.53 ± 1.00) x 10 -4 , where the uncertainties are statistical, systematic, and that from the branching fraction of $\psi$(3686) → $π^oh_c$. Strong evidence for the decay $h_c$ → $p\overline{p}π^+π^-π^o$ is found with a significance of 4.9σ and a branching fraction of (3.84 ± 0.83 ± 0.69 ± 0.58) x 10 -3 . The significances include systematic uncertainties. No clear signal of the decay $h_c$ → $p\overline{p}π^o$ is found, and an upper limit of 6.59 x 10 -4 on its branching fraction is set at the 90% confidence level.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Measurement of e + e – → $\mathrm{K^+K^–π^0}$ cross section and observation of a resonant structure

Based on collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process $e^+e^–$→ $K^+K^–π^0$. The Born cross section of the process $e^+e^–$→ $K^+K^–π^0$ and its subprocesses $e^+e^–$ → $\phi π^0, K^{*+}$(892)$K^–$ and $K^{*+}_{2}$(1430)$K^–$ are measured. The results for $e^+e^–$→ $K^+K^–π^0$ and $\phi π^0$ are consistent with the BaBar measurements and with improved precision. By analyzing the cross sections of the subprocesses $e^+e^–$ → $K^{*+}$(892)$K^–$ and $K^{*+}_{2}$(1430)$K^–$ a structure with mass $M_R$ = (2190 ± 19 ± 37) MeV/c 2 and width $Γ_R$ = (191 ± 28 ± 60) MeV is observed with a combined statistical significance of 7.1σ. The measured resonance parameters suggest it can be identified as the $\phi$(2170), thus the results provide valuable input to understand the internal nature of this state.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Cross section measurements of the processes $e^+e^–$ → $ωπ^0$ and $ωη$ at center-of-mass energies between 3.773 and 4.701 GeV

The Born cross sections of the processes $e^+e^–$ → $ωπ^0$ and $e^+e^–$ → $ωη$ are measured at center-of-mass energies between 3.773 and 4.701 GeV using a total integrated luminosity of 22.7 fb –1 collected with the BESIII detector operating at the BEPCII collider. A simple $s^{-n}$ dependence for the continuum process can describe the measured Born cross sections. No significant contributions from the ψ(4160), Y(4230), Y(4360), ψ(4415), Y(4660) resonances are found, which indicates relative small branching fractions for these resonances into the $ωπ^0$ and $ωη$ final states.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2025

Chloride Molten Salt Electrolysis Enables Integrated and Energy-Efficient Process for NdFeB Magnet Fabrication

Rare-earth elements (REEs) have been identified by NATO, the USDOE, and USGS as critical materials, i.e., materials which have significant demand yet pose supply-chain risks. Many of the existing processes for separations, metallization, and final parts production used across the REE supply chain involve energy intensive steps. For example, neodymium (Nd or NdPr) is produced using oxyfluoride electrolysis of Nd 2 O 3 , which requires hydrofluoric acid to produce a key electrolyte component (NdF 3 ) and generates undesired perfluorocarbon (PFC) gases. Such challenges make securing a resilient supply chain for NdFeB permanent magnets in countries like the United States prohibitively difficult. Here, we propose a chloride-based MSE process that circumvents these challenges, delivering high-purity NdPr from a (NdPr)Cl 3 feed from upstream REE separations. This eliminates environmentally-damaging steps of oxalate or carbonate precipitation and calcination, and enables superior production rates due to greater solubility of (NdPr)Cl 3 in chloride melts compared to Nd 2 O 3 . We show that CMSE generates high-purity NdPr (99.4 wt.%) while being energy-efficient (~ 6 kWh/kg-Nd). NdPr from CMSE was used to fabricate a NdFeB magnet with an excellent maximum energy product (> 40 MGOe), comparable to commercially available NdFeB magnets. This establishes CMSE as a leading approach for integrated, energy-efficient NdFeB magnet production.

Materials science↗
DOE OSTI2021

A U.S.-China coal power transition and the global 1.5 °C pathway

As the world seeks to increase ambition rapidly to limit global warming to 1.5 °C, joint leadership from the world's largest greenhouse gas (GHG) emitters—the United States (U.S.) and China—will be critical to deliver significant emissions reductions from their own countries as well as to catalyze increased international action. After a period of uncertainty in international climate policy, these countries now both have current leadership that supports ambitious climate action. In this context, a feasible, high-impact, and potentially globally catalytic agreement by the U.S. and China to transition away from coal to clean energy would be a major contribution toward this global effort. We undertake a plant-by-plant assessment in the power sector to identify practical coal retirement pathways for each country that are in line with national priorities and the global 1.5 °C target. Our plant-by-plant analysis shows that the 1.5 °C-compatible pathways may result in an average retirement age of 47 years for the U.S. coal plants and 22 years for Chinese coal plants, raising important questions of how to compare broader economic, employment, and social impacts. We also demonstrate that such pathways would also lead to significant emissions reductions, lowering overall global energy-related CO 2 emissions by about 9% in 2030 relative to 2020. A catalytic effect from the possibility of other countries taking compatible actions is estimated to reduce global emissions by 5.1 Gt CO 2 in 2030 and by 10.1 Gt CO 2 in 2045.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Overcoming mechanical fragility in Sm-Co permanent magnet materials

Samarium-cobalt alloys are used in some of the strongest permanent magnets, particularly for applications between about 200 and 550°C, but the utilization of these materials is restricted by their brittleness. Improving their mechanical resilience would allow them to be used more widely and, in some cases, substitute for neodymium-based magnet alloys which are subject to supply-chain risks. In this work, we have engineered a series of novel microstructures with bi-modal grain size distributions to achieve unprecedented combinations of mechanical and magnetic properties. Improvements up to 73% are obtained in the flexural strength of Sm 2 (CoFeCuZr) 17 sintered magnets, with negligible impact on the magnetic properties. Our mechanically-robust, high-performance Sm-Co magnets are made without changing the chemical compositions of the materials or their heat treatment procedures, making them highly compatible with existing manufacturing processes.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Enhancement of high-temperature selectivity on Cu-SSZ-13 towards NH3-SCR reaction from highly dispersed ZrO2

ZrO2 is introduced as a secondary phase to Cu-SSZ-13 via different approaches and tested for the NH3-SCR reaction. It is shown that the vicinity between the two catalyst phases, i.e., ZrO2 dispersion, influences interaction between copper oxide (CuOx) on Cu-SSZ-13 and ZrO2. A strong interaction is achieved when ZrO2 is formed with high dispersion on Cu-SSZ-13, and leads to the chemical interaction of CuOx and ZrO2 in hydrothermally aged catalysts. The result is formation of a Cu-stabilized t-ZrO2 phase which greatly hinders the non-selective NH3 oxidation due to CuOx. With reduced ZrO2 dispersion and less Cu-SSZ-13 and ZrO2 interaction, the beneficial role of ZrO2 is diminished. This strategy of CuOx passivation is able to significantly enhance the high-temperature selectivity of the state-of-the-art NH3-SCR catalytic system while mitigating the adverse impact of CuOx clusters on the zeolite, potentially enabling higher Cu-content SCR catalysts and improved low-temperature activity.

NH3-SCR, ZrO2, selective catalytic reduction, afte↗
DOE OSTI2026

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Mechanically strengthened heterogeneous Sm-Co sintered magnets

Samarium-cobalt sintered magnets offer excellent magnetic properties, thermal stability, and corrosion resistance. They are used in a variety of defense and civilian applications, especially when elevated operation temperatures (e.g., 200 ºC to 550 ºC) are required. However, the utilization of these materials is restricted by their brittleness. Improving their mechanical resilience would make them more cost-effective, efficient, and robust in decarbonization and other function-related applications while reducing the pressure on critical material supply chains. In this paper, we engineer a series of novel heterogeneous microstructures, such as laminated coarse grain (CG)/fine grain (FG) and core/shell CG/FG microstructures, to produce unprecedented combinations of superior mechanical and magnetic properties without altering the chemical compositions of the magnets or common heat treatment procedures. Further, a 60% flexural strength enhancement is obtained using heterogeneous Sm 2 (CoFeCuZr) 17 sintered magnets with little impact on their magnetic properties. The mechanically robust heterogeneous Sm-Co sintered magnets have a minor (e.g., less than 4.6%) reduction in the energy product (BH) max due to a slightly reduced squareness of the demagnetization curve, with no decrease in either the remanence (B r ) or the intrinsic coercivity (H ci ). The flexural strengths of these heterogeneous Sm-Co magnets depend on the volume ratios and mean grain sizes of the FG/CG regions, as well as their microstructural architectures. The fine-grained regions act as mechanical strengthening sites, which can be strategically used when designing the magnet for different applications. This technology is highly compatible with existing magnet manufacturing processes and thus can be adopted readily by the magnet industry.

36 MATERIALS SCIENCE↗