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35 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Stabilizing Metallic Na Anodes via Sodiophilicity Regulation: A Review

This review focuses on the Na wetting challenges and relevant strategies regarding stabilizing sodium-metal anodes in sodium-metal batteries (SMBs). The Na anode is the essential component of three key energy storage systems, including molten SMBs (i.e., intermediate-temperature Na-S and ZEBRA batteries), all-solid-state SMBs, and conventional SMBs using liquid electrolytes. We begin with a general description of issues encountered by different SMB systems and point out the common challenge in Na wetting. We detail the emerging strategies of improving Na wettability and stabilizing Na metal anodes for the three types of batteries, with the emphasis on discussing various types of tactics developed for SMBs using liquid electrolytes. We conclude with a discussion of the overlooked yet critical aspects (Na metal utilization, N/P ratio, critical current density, etc.) in the existing strategies for an individual battery system and propose promising areas (anolyte incorporation and catholyte modifications for lower-temperature molten SMBs, cell evaluation under practically relevant current density and areal capacity, etc.) that we believe to be the most urgent for further pursuit. Comprehensive investigations combining complementary post-mortem, in situ, and operando analyses to elucidate cell-level structure-performance relations are advocated.

25 ENERGY STORAGE↗
NASA NTRS1977

The development of a potassium-sulfide glass fiber cell and studies on impurities in alkali metal-sulfur cells

Potassium sulfur rechargeable cells, having as the electrolyte the thin walls of hollow glass fibers made from permeable glass, were developed. The cells had short lives, probably due to the construction materials and impurities in the potassium. The effect of the impurities in the analogous NA-S system was studied. Calcium, potassium, and NaOH/oxide impurities caused increased resistance or corrosion of the glass fibers. For long lived cell operation, the Na must contain less than 1 ppm Ca and less than a few ppm of hydroxide/oxide. Up to 150 ppm K can be tolerated. After purification of the Na anolyte, cell lifetimes in excess of 1000 deep charge-discharge cycles or over 8 months on continuous cycling at 10-30 percent depth of discharge were obtained.

Tsang, F. Y.↗
NASA NTRS1981

Comparison of electrochemical and thermal storage for hybrid parabolic dish solar power plants

The economic and operating performance of a parabolic point focus array of solar electricity generators combined with either battery or thermal energy storage are examined. Noting that low-cost, mass-producible power generating units are under development for the point focus of distributed dishes, that Zn-Cl battery tests will begin in 1981 and a 100 kWh Na-S battery in 1983, the state of thermal storage requires acceleration to reach the prototype status of the batteries. Under the assumptions of 10,000 units/yr with an expected 30 yr lifetime, cost comparisons are developed for 10 types of advanced batteries. A 5 MWe plant with full thermal or 80% battery storage discharge when demand occurs in conditions of no insolation is considered, specifically for Fe-Cr redox batteries. A necessity for the doubling of fuel prices from 1980 levels by 1990 is found in order to make the systems with batteries economically competitive.

Steele, H. L.↗
NASA NTRS1982

Comparison of advanced thermal and electrical storage for parabolic dish solar thermal power systems

Parabolic dish solar concentrator cluster concepts are explored, with attention given to thermal storage systems coupled to Stirling and Brayton cycle power conversion devices. Sensible heat storage involving molten salt (NaOH), liquid sodium, and solid cordierite bricks are considered for 1500 F thermal storage systems. Latent heat storage with NaF-MgF2 phase change materials are explored in terms of passive, active, and direct contact designs. Comparisons are made of the effectiveness of thermal storage relative to redox, Na-S, Zn-Cl, and Zn-Br battery storage systems. Molten lead trickling down through a phase change eutectic, the NaF-MgF2, formed the direct contact system. Heat transport in all systems is effected through Inconel pipes. Using a cost goal of 120-150 mills/kWh as the controlling parameter, sensible heat systems with molten salts transport with either Stirling or Brayton engines, or latent heat systems with Stirling engines, and latent heat-Brayton engine with direct contact were favored in the analyses. Battery storage systems, however, offered the most flexibility of applications.

Fujita, T.↗
NASA NTRS1988

Energy storage considerations for a robotic Mars surface sampler

The characteristics of various energy storage systems (including Ni-Cd, Ni-H2, Ag-Zn, Li-XS, Na-S, PbSO4, and regenerative fuel cell systems) considered for a robotic Mars surface sampler are reviewed. It is concluded that the bipolar nickel-hydrogen battery and the sodium-sulfur battery are both viable candidates as storage systems for the rover's Radioisotope Thermoelectric Generator. For a photovoltaic storage system, the regenerative fuel cell and the bipolar nickel-hydrogen battery are the primary candidates.

O'Donnell, P. M.↗
DOE OSTI2022

Molybdenum Carbide Electrocatalyst In Situ Embedded in Porous Nitrogen–Rich Carbon Nanotubes Promotes Rapid Kinetics in Sodium–Metal–Sulfur Batteries

This work is the first report of a molybdenum carbide-based electrocatalyst for sulfur-based sodium metal batteries (SMBs/NMBs). MoC/Mo 2 C is in-situ grown on nitrogen-doped carbon nanotubes in parallel with formation of extensive nanoporosity. Sulfur impregnation (50 wt% S) results in unique triphasic architecture termed MoC/Mo 2 C@PCNT-S. Quasi-solid-state phase transformation to Na 2 S is promoted in carbonate electrolyte, with in-situ time-resolved Raman, XPS and optical analysis demonstrating minimal soluble polysulfides. MoC/Mo 2 C@PCNT-S cathodes delivered among the most promising rate performance characteristics in literature, achieving 987 mAh g -1 at 1 Ag -1 , 818 mAh g -1 at 3 A g -1 , and 621 mAh g -1 at 5 A g -1 . The cells deliver superior cycling stability, retaining 650 mAh g -1 after 1000 cycles at 1.5 Ag -1 , corresponding to 0.028% capacity decay per cycle. High mass loading cathodes (64 wt% S, 12.7 mg cm -2 ) also show cycling stability, with anode degradation due to deep plating/stripping driving capacity decay. Density functional theory (DFT) demonstrates that formation energy of Na 2 S x (1 ≤ x ≤ 4) on surface of MoC/Mo 2 C is significantly lowered compared to analogous redox in liquid. Strong binding of Na 2 S x (1 ≤ x ≤ 4) on MoC/Mo 2 C surfaces results from charge transfer between the sulfur and Mo sites on carbides' surface.

25 ENERGY STORAGE↗
DOE OSTI2020

Materials Data on NaS2 by Materials Project

NaSS crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 4-coordinate geometry to six S atoms. There are a spread of Na–S bond distances ranging from 2.85–3.27 Å. In the second Na site, Na is bonded in a 6-coordinate geometry to six S atoms. There are a spread of Na–S bond distances ranging from 2.91–3.11 Å. There are two inequivalent S sites. In the first S site, S is bonded in a 5-coordinate geometry to four Na and one S atom. The S–S bond length is 2.09 Å. In the second S site, S is bonded in a 4-coordinate geometry to two Na and two S atoms. The S–S bond length is 2.07 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaS by Materials Project

NaS crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six equivalent S1- atoms to form edge-sharing NaS6 octahedra. All Na–S bond lengths are 3.00 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six equivalent S1- atoms. All Na–S bond lengths are 2.82 Å. S1- is bonded in a 7-coordinate geometry to six Na1+ and one S1- atom. The S–S bond length is 2.17 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2S5 by Materials Project

Na2S5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven S+0.40- atoms. There are a spread of Na–S bond distances ranging from 2.90–3.06 Å. In the second Na1+ site, Na1+ is bonded to six S+0.40- atoms to form corner-sharing NaS6 octahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Na–S bond distances ranging from 2.94–3.08 Å. There are three inequivalent S+0.40- sites. In the first S+0.40- site, S+0.40- is bonded in a 4-coordinate geometry to two Na1+ and two S+0.40- atoms. There are one shorter (2.07 Å) and one longer (2.08 Å) S–S bond lengths. In the second S+0.40- site, S+0.40- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two equivalent S+0.40- atoms. In the third S+0.40- site, S+0.40- is bonded in a 5-coordinate geometry to four Na1+ and one S+0.40- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaS by Materials Project

NaS crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six S1- atoms. There are four shorter (2.86 Å) and two longer (2.89 Å) Na–S bond lengths. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six S1- atoms. There are two shorter (2.94 Å) and four longer (2.96 Å) Na–S bond lengths. There are two inequivalent S1- sites. In the first S1- site, S1- is bonded in a 7-coordinate geometry to six Na1+ and one S1- atom. The S–S bond length is 2.15 Å. In the second S1- site, S1- is bonded in a 7-coordinate geometry to six Na1+ and one S1- atom. The S–S bond length is 2.14 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2S by Materials Project

Na2S is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four equivalent S2- atoms to form NaS4 tetrahedra that share corners with eight equivalent NaS5 square pyramids, corners with eight equivalent NaS4 tetrahedra, edges with six equivalent NaS5 square pyramids, and edges with two equivalent NaS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.75–2.84 Å. In the second Na1+ site, Na1+ is bonded to five equivalent S2- atoms to form distorted NaS5 square pyramids that share corners with eight equivalent NaS5 square pyramids, corners with eight equivalent NaS4 tetrahedra, edges with six equivalent NaS5 square pyramids, and edges with six equivalent NaS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.90–3.26 Å. S2- is bonded in a 9-coordinate geometry to nine Na1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2S by Materials Project

Na2S is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Na1+ is bonded to four equivalent S2- atoms to form a mixture of edge and corner-sharing NaS4 tetrahedra. All Na–S bond lengths are 2.85 Å. S2- is bonded in a body-centered cubic geometry to eight equivalent Na1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2S by Materials Project

Na2S crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to five equivalent S2- atoms to form distorted NaS5 trigonal bipyramids that share corners with twelve equivalent NaS6 octahedra, corners with eight equivalent NaS5 trigonal bipyramids, edges with six equivalent NaS5 trigonal bipyramids, and faces with six equivalent NaS6 octahedra. The corner-sharing octahedra tilt angles range from 32–58°. There are three shorter (2.69 Å) and two longer (3.32 Å) Na–S bond lengths. In the second Na1+ site, Na1+ is bonded to six equivalent S2- atoms to form NaS6 octahedra that share corners with twelve equivalent NaS6 octahedra, corners with twelve equivalent NaS5 trigonal bipyramids, edges with six equivalent NaS6 octahedra, faces with two equivalent NaS6 octahedra, and faces with six equivalent NaS5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 50°. All Na–S bond lengths are 3.16 Å. S2- is bonded in a 3-coordinate geometry to eleven Na1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaS by Materials Project

NaS is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Na1+ is bonded to six equivalent S1- atoms to form a mixture of corner and edge-sharing NaS6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Na–S bond lengths are 2.87 Å. S1- is bonded to six equivalent Na1+ atoms to form a mixture of corner and edge-sharing SNa6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaS by Materials Project

NaS is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight equivalent S1- atoms. All Na–S bond lengths are 2.94 Å. S1- is bonded in a body-centered cubic geometry to eight equivalent Na1+ atoms.

36 MATERIALS SCIENCE↗