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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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g-C3N4 promoted MOF derived hollow carbon nanopolyhedra doped with high density/fraction of single Fe atoms as an ultra-high performance non-precious catalyst towards acidic ORR and PEM fuel cells
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Thiol-promoted catalytic synthesis of high-performance furan-containing lubricant base oils from biomass derived 2-alkylfurans and ketones
About 97% of lubricant base oils are currently sourced from petroleum and the majority of the rest is produced from vegetable oils. We demonstrate a promising catalytic route to produce base oils from lignocellulosic biomass-derived 2-alkylfurans and ketones via carbon–carbon coupling in neat conditions. Among several homogeneous and heterogeneous acid catalysts tested, a perfluorinated sulfonic acid (Aquivion PW79S) exhibits the best catalytic performance and yields up to 90% renewable furan-containing base oils with the use of a thiol promotor. The effects of the acid strength of the catalysts, molecular size and structure of thiols and ketones, and fraction of thiols are studied. Electronic structure calculations elucidate the reaction pathway and indicate that the thiol reduces the barrier of the rate-determining dehydration step. The structure and properties of base oils can be tuned by using different synthons. Here, these base oils have excellent properties and can be competitive with or surpass the commercial synthetic alkylnaphthalene and furan-containing bio-ester base oils.
Suppressing vanadium crossover using sulfonated aromatic ion exchange membranes for high performance flow batteries
Novel ion exchange membrane with just the right width of selective aqueous ionic domain (<0.6 nm) and unique functionalities show extraordinary ion selectivity. These unique ion transport properties of our membrane is reflected in a remarkable flow battery performance.
Multi-channel V-doped CoP hollow nanofibers as high-performance hydrogen evolution reaction electrocatalysts
Abstract not provided
Incorporation of alkylthio side chains on benzothiadiazole-based non-fullerene acceptors enables high-performance organic solar cells with over 16% efficiency
This is the first time alkylthio chains are employed on Y6-like NFAs to achieve organic solar cells of power conversion efficiency higher than 16%.
Cation-disorder zinc blende Zn 0.5 Ge 0.5 P compound and Zn 0.5 Ge 0.5 P–TiC–C composite as high-performance anodes for Li-ion batteries
Zn 0.5 Ge 0.5 P shows superior crystal and band structure as anode material for lithium-ion batteries, and Zn 0.5 Ge 0.5 P–TiC–C exhibits excellent electrochemical performance.
Tetragonal CoMn 2 O 4 nanocrystals on electrospun carbon fibers as high-performance battery-type supercapacitor electrode materials
A novel C@CoMn 2 O 4 composite material was fabricated, having improved performance as a battery-type electrode for supercapacitor applications.
High-performance carbon nanotube electronic ratchets
The rapid advancements in low-power portable/wearable electronic devices require concurrent development of technologies that can provide power without the need for bulky, heavy battery storage. Electronic ratchets, asymmetric transistor-based devices that can convert AC signals or electronic noise into DC power, have been proposed as one solution to this growing need. Here, the recent demonstration of conjugated polymer-based electronic ratchets offers a route toward lightweight, flexible power sources for portable applications. Here we demonstrate the fabrication of the first electronic ratchets where the active channel component consists of semiconducting single-walled carbon nanotubes (s-SWCNTs), which can transform electronic noise or AC signals to a stable DC current with higher output power (up to ca. 14 mW for a chemically doped device) than their polymer-based analogs. We also show that patterning of the dopant profile in the s-SWCNT channel enables reasonable power conversion performance (ca. 3.5 mW) with improved stability relative to homogeneously doped devices. Our findings demonstrate the promise for s-SWCNT electronic ratchets as energy harvesting devices for portable, low-power applications.
Chelator-assisted high performance liquid chromatographic separation of trivalent lanthanides and actinides
3,4,3-LI(1,2-HOPO) can be used as a HPLC chelating agent, promoting lanthanide and trivalent actinide separation without column modifications.
High-performance anthraquinone with potentially low cost for aqueous redox flow batteries
Alkaline anthraquinone flow battery with active species exhibiting long lifetime and potentially low mass-production cost.
Challenge-driven printing strategies toward high-performance solid-state lithium batteries
Solid-state lithium batteries (SSLBs) are promising candidates for replacing traditional liquid-based Li-ion batteries and revolutionizing battery systems for electric vehicles and portable devices. However, longstanding issues such as form factors, interfacial contact resistance, balance between ion conductivity and mechanical strength, and manufacturing processability limit their applications. In this review we present how advanced printing technologies can help to mitigate typical problems in main components of SSLBs and improve device performance. Here we first introduce the common printing techniques for energy storage devices, then focus on the issues and corresponding printing strategies for anodes, cathodes, and solid-state electrolytes to guide the construction of energy-dense, free-form SSLBs. The features and effects of the printed structures are emphasized, as well. We conclude by discussing the problems associated with printing technologies and the potential research directions for printed solid-state batteries.
Interplay of structural fluctuations and charge carrier dynamics is key for high performance of hybrid lead halide perovskites
The ability of methylammonium lead triiodide (MAPbI 3 ) to achieve photoelectric conversion efficiency that is on par with crystalline silicon has led to a surge of interest in perovskite photovoltaics. However, an in-depth understanding of how the ubiquitous coupling between the fast rovibrational movements of the organic cations and the phonon vibrations of the inorganic framework affects the relaxation and recombination of hot carriers remains largely elusive. Access to such knowledge is critical to guide design and increase efficiency of new classes of perovskite solar cells. In this report, we report a time-domain ab initio investigation of temperature dependent excited state dynamics in MAPbI 3 , with particular emphasis on nuclear anharmonic effects. The observed strong anharmonicity is attributed to softness of the material and unusual dynamical coupling between the organic and inorganic components. At an elevated temperature, the hydrogen bonding between MA and iodines is weakened, enhancing rotation of MA cations, which become more dynamically disordered. As a result, thermal vibrations of the inorganic Pb–I sublattice are suppressed, and the lattice anharmonicity is decreased. Thermal fluctuations of the electronic energy levels are found to follow the trend of anharmonic motions of Pb and I atoms, with holes relaxing faster to the band edges than electrons, due to higher density of the hole states. While elevated temperature accelerates intraband carrier cooling, it slows nonradiative carrier recombination. The latter result is important for performance, since solar cells and other devices heat up during operation. The reported signatures of coupled structural dynamics of the organic cations and inorganic framework unravel the interplay between anomalous structural fluctuations and charge carrier dynamics, which is of particular importance for fundamental understanding of the structure–property relationships in hybrid metal halide perovskites.
Organic-modified ZnS nanoparticles as a high-performance lubricant additive
Oil-miscible and oil-transparent organic modified ZnS nanoparticles were developed as an antiwear additive to improve lubricant performance.
Low-cobalt active cathode materials for high-performance lithium-ion batteries: synthesis and performance enhancement methods
This review describes the advancements in the field of Ni-rich NCM cathodes in terms of manufacturing processes, material challenges, modification techniques, and future research directions, and discusses the correlation between the synthesis and electrochemical performance.
High-performance semitransparent organic solar cells based on sequentially processed heterojunction
Semitransparent organic solar cells based on sequentially processed heterojunction (SHJ) structure show a power conversion efficiency (PCE) of 12.5% and an average visible transmittance (AVT) of 25.4%, outperforming the BHJ counterpart (PCE = 11.8%, AVT = 22.9%).