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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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5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Hydrogen-Bonding Reinforced Flexible Composite Electrodes for Enhanced Energy Storage

The lack of advanced electrode materials is one of the main factors hindering the development of flexible rechargeable aqueous batteries (RABs) for high specific energy density and structural stability. It is also challenging to achieve high-capacity performance for both the positive and negative electrodes simultaneously. In this work, it is demonstrated that, by smartly designing the composite structures of positive and negative electrodes via one-step electrodeposition strategy, the energy storage performance of the RAB is largely enhanced. For positive electrode material synthesis, Co-Cu double hydroxides (Co-Cu-DH) nanosheets are skillfully rooted into electroreduced graphene oxide (eRG) via hydrogen bonding, in which graphene oxide reduction, Co-Cu-DH nucleation/growth, and formation of hydrogen bonding between Co-Cu-DH and eRG simultaneously occur. Moreover, when a RAB based on Co-Cu-DH@eRG//FeOOH@eRG using the same composite design strategy is established, a wide operating voltage window of ≈1.8 V, a high specific energy density of ≈142.8 Wh kg –1 at ≈890 W kg –1 , and long-term cyclic stability (88.5% of capacity retention after 12 000 cycles) are obtained. This study presents a general compositing strategy for the development of advanced electrode materials, and it is expected to stimulate future material synthesis/design in RABs toward the goal of high energy density storage.

25 ENERGY STORAGE↗
DOE OSTI2023

Revealing CO 2 dissociation pathways at vicinal copper (997) interfaces

Size- and shape-tailored copper (Cu) nanocrystals can offer vicinal planes for facile carbon dioxide (CO 2 ) activation. Despite extensive reactivity benchmarks, a correlation between CO 2 conversion and morphology structure has not yet been established at vicinal Cu interfaces. Herein, ambient pressure scanning tunneling microscopy reveals step-broken Cu nanocluster evolutions on the Cu(997) surface under 1 mbar CO 2 (g). The CO 2 dissociation reaction produces carbon monoxide (CO) adsorbate and atomic oxygen (O) at Cu step-edges, inducing complicated restructuring of the Cu atoms to compensate for increased surface chemical potential energy at ambient pressure. The CO molecules bound at under-coordinated Cu atoms contribute to the reversible Cu clustering with the pressure gap effect, whereas the dissociated oxygen leads to irreversible Cu faceting geometries. Synchrotron-based ambient pressure X-ray photoelectron spectroscopy identifies the chemical binding energy changes in CO-Cu complexes, which proves the characterized real-space evidence for the step-broken Cu nanoclusters under CO(g) environments. Our in situ surface observations provide a more realistic insight into Cu nanocatalyst designs for efficient CO 2 conversion to renewable energy sources during C 1 chemical reactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2002

Atomistic Modeling of Co Growth on Cu(111]

The BFS method for alloys is applied to the study of Co growth on Cu(111). The parameterization of the Co-Cu system is obtained from first-principles calculations, and tested against known experimental features for low coverage Co deposition on Cu(100) and Cu(111). Atomistic simulations are performed to investigate the behavior of Co on Cu(111) as a function of coverage.

Khalil, Joseph↗
NASA NTRS2003

Atomistic Modeling of Nanostructures via the BFS Quantum Approximate Method

Ideally, computational modeling techniques for nanoscopic physics would be able to perform free of limitations on the type and number of elements, while providing comparable accuracy when dealing with bulk or surface problems. Computational efficiency is also desirable, if not mandatory, for properly dealing with the complexity of typical nano-strucured systems. A quantum approximate technique, the BFS method for alloys, which attempts to meet these demands, is introduced for the calculation of the energetics of nanostructures. The versatility of the technique is demonstrated through analysis of diverse systems, including multi-phase precipitation in a five element Ni-Al-Ti-Cr-Cu alloy and the formation of mixed composition Co-Cu islands on a metallic Cu(III) substrate.

Bozzolo, Guillermo↗
DOE OSTI2020

Materials Data on Co3Cu by Materials Project

Co3Cu is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Co sites. In the first Co site, Co is bonded to eight Co and four equivalent Cu atoms to form CoCo8Cu4 cuboctahedra that share corners with twelve equivalent CoCo8Cu4 cuboctahedra, edges with eight equivalent CuCo12 cuboctahedra, edges with sixteen CoCo8Cu4 cuboctahedra, faces with four equivalent CuCo12 cuboctahedra, and faces with fourteen CoCo8Cu4 cuboctahedra. There are four shorter (2.50 Å) and four longer (2.51 Å) Co–Co bond lengths. All Co–Cu bond lengths are 2.51 Å. In the second Co site, Co is bonded to eight equivalent Co and four equivalent Cu atoms to form CoCo8Cu4 cuboctahedra that share corners with four equivalent CoCo8Cu4 cuboctahedra, corners with eight equivalent CuCo12 cuboctahedra, edges with twenty-four CoCo8Cu4 cuboctahedra, faces with six equivalent CuCo12 cuboctahedra, and faces with twelve CoCo8Cu4 cuboctahedra. All Co–Cu bond lengths are 2.50 Å. Cu is bonded to twelve Co atoms to form CuCo12 cuboctahedra that share corners with four equivalent CuCo12 cuboctahedra, corners with eight equivalent CoCo8Cu4 cuboctahedra, edges with eight equivalent CuCo12 cuboctahedra, edges with sixteen equivalent CoCo8Cu4 cuboctahedra, faces with four equivalent CuCo12 cuboctahedra, and faces with fourteen CoCo8Cu4 cuboctahedra.

36 MATERIALS SCIENCE↗