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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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Reduced Surface Recombination Velocity in Mixed-Cation Mixed-Halide Hybrid Perovskite Devices Leads to Improved Open-Circuit Voltage

Surface recombination plays an important role in perovskite solar cell performance.Despite rapid progress, the record power conversion efficiency (PCE, ~ 25.7%) for perovskite single-junction solar cells still lags behind its theoretical limit (~ 32%), largely due to the open circuit voltage (VOC) deficit that results from non-radiative recombination at the bulk of perovskite films and the interfaces between perovskite and transport layers. In this work, we show that (3-aminopropyl)trimethoxysilane (APTMS) surface passivation can reduce the surface recombination velocities (SRVs) of perovskite solar cells, thus improving device VOC and PCE.

perovskite solar cell, surface recombination, surf↗
DOE OSTI2022

Design of Next-Gen Cathode Materials With Both Cation and Anion Redox

Among all candidates of positive electrode materials for lithium ion batteries, the lithium rich layered oxides have gained growing research interests in recent years. Their energy density can reach closely to 700-900Wh/g (at materials level), making them the positive electrode materials with highest energy density among all known intercalation compounds for cathode materials. Combining both first principles computation, advanced electron and X-ray based imaging, we demonstrated that in the Li-rich materials oxygen vacancies are present and assist the transition metal ion migration through a facile mechanism. This means it is critically important to control the oxygen activities in these compounds for high voltage operations. In addition, the NiMn spinel oxides show little oxygen activities and under optimized synthesis condition the electrolyte/electrode interface showed superior stability. Combining the strengths of materials synthesis and the advanced characterization, I will discuss in details the strategies for stabilizing the anion redox for higher voltage electrode materials for lithium ion batteries.

Meng, Ying Shirley↗
DOE OSTI2023

Cation Exchange Capacity, Anion Exchange Capacity, and Mineralogy of F-Area Aquifer Sediments

Strontium-90 (Sr-90) is a contaminant of concern in groundwater and surface water at both F-Area and H-Area Seepage Basins. This contaminant was disposed of, along with other heavy metals and radionuclides, into a series of unlined seepage basins from 1955 until 1988. The acidity of the wastewater increased Sr-90 mobility from the basin soil through the vadose zone and into the Upper Aquifer Zone (UAZ), creating a groundwater plume that discharges into wetlands areas and a local stream called Fourmile Branch.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1967

Hydrated multivalent cations are new class of molten salt mixtures

Electrical conductance and activation energy measurements on mixtures of calcium and potassium nitrate show the hydrated form to be a new class of molten salt. The theoretical glass transition temperature of the hydrate varied in a manner opposite to that of the anhydrous system.

Angell, C. A.↗