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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 361 records · Page 20

Conductive trace interconnection tape

A conductive trace interconnect tape for use with a printed circuit board or a flexible circuit substrate comprises a top insulating layer, an electrically conductive layer, and a bottom insulating layer. The top insulating layer is formed from electrically insulating material and is configured to provide electrical isolation from electrically conductive objects that are positioned on top of the conductive trace interconnect tape. The electrically conductive layer is positioned underneath the top insulating layer. The electrically conductive layer is formed from electrically conductive material and includes electrical interconnect traces, electrical component pads, or electrically conductive planar portions. The bottom insulating layer is positioned underneath the electrically conductive layer. The bottom insulating layer is formed from electrically insulating material and is configured to provide electrical isolation from electrically conductive objects that are positioned on the printed circuit board or flexible circuit substrate.

Hatch, Stephen McGarry↗

Conductive trace interconnection tape

A conductive trace interconnect tape for use with a printed circuit board or a flexible circuit substrate comprises a top insulating layer, an electrically conductive layer, and a bottom insulating layer. The top insulating layer is formed from electrically insulating material and is configured to provide electrical isolation from electrically conductive objects that are positioned on top of the conductive trace interconnect tape. The electrically conductive layer is positioned underneath the top insulating layer. The electrically conductive layer is formed from electrically conductive material and includes electrical interconnect traces, electrical component pads, or electrically conductive planar portions. The bottom insulating layer is positioned underneath the electrically conductive layer. The bottom insulating layer is formed from electrically insulating material and is configured to provide electrical isolation from electrically conductive objects that are positioned on the printed circuit board or flexible circuit substrate.

Hatch, Stephen McGarry↗

Binder systems and methods for tape casting lithium garnet electrolytes

Slurry compositions, tape casting binder systems and fabrication methods for the fabrication of lithium-garnet electrolyte scaffolds for use in solid state batteries and other devices are provided. Slurry compositions may be optimized mixtures of LLZO powder, a dispersant, a lithium salt, a wetting agent a binder, a plasticizer and at least one solvent. The optimized ceramic slurry compositions may include MgO as a sintering additive to improve density and ionic conductivity of the doped-LLZO sheets and produce a fine-grained microstructure. Sintering protocols for cast slurries of commercially available doped LLZO powders eliminate the requirement of mother-powder coverings or externally applied pressure. An environmentally friendly water-based system using methylcellulose as a binder is also provided producing green tape and final properties comparable to those obtained with organic solvent-based systems.

Jonson, Robert↗

Performance and durability of electrically conductive tape for shingled Si heterojunction technology cells

We report electrically conductive tape (ECT) was characterized and used to assemble shingled cell strings at low temperature to achieve high reliability Pb- and Ag-free interconnections. The volume resistivity for two considered ECTs are 0.13 ± 0.06 mΩ·cm and 0.47 ± 0.20 mΩ·cm and specific contact resistances, 6.85± 2.00 mΩ·cm 2 and 6.30 ± 0.37 mΩ·cm 2 using the emerging IEC 62788-8-1 Technical Specification for assessment of electrically conductive adhesives (ECA). Durability and performance of the technology in glass–glass mini modules were evaluated with temperature cycling, damp heat testing, and combined-accelerated stress testing (CAST). Through temperature cycling (-40°C to 85°C) applying five times the mini module short-circuit current in forward bias and in the multi climate CAST protocol, there was negligible degradation of fill factor after replacing connectors at the modules' cable leads; however, CAST resulted in short circuit current loss attributed to degradation in light collection by the cells, not the ECT. The IEC 61215-2 85°C, 85% relative humidity damp heat testing showed susceptibility of the HJT cells to effects of humidity in the electroluminescence intensity around the module perimeter that degraded power performance by 4% (relative). Contrasting the IEC 61215-2 qualification testing-based damp heat testing with CAST, factors such as the optical stress of CAST may precipitate the degradation of the modules whereas the humidity levels and duration of IEC 61215-2 damp heat testing may lead to excessive levels of humidity diffused into the modules, potentially resulting in degradation that is unrepresentative of the field.

14 SOLAR ENERGY↗

Freeze Tape Casting Electrode with Bilayered Architecture for High-Performance Lithium-Ion Batteries

A facile freeze tape casting (FTC) strategy is utilized to prepare bilayered 4 mAh cm –2 high-loading LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathodes. The bottom layer is a conventional nonaqueous electrode, which has a dense structure for high-energy purposes. Further, the top layer is prepared by the proposed FTC, exhibiting a porous feature for high-power requirement. With the assistance of FTC, the bilayered electrodes successfully deliver enhanced rate and cyclic performance due to the improved lithium-ion diffusion kinetics and pathways. Therefore, the proposed FTC strategy and its delivered electrodes are promising for energy- and power-density lithium-ion batteries, potentially enlightening the research and development of lithium-ion battery manufacturing.

25 ENERGY STORAGE↗

Scalable Freeze-Tape-Casting Fabrication and Pore Structure Analysis of 3D LLZO Solid-State Electrolytes

Nonflammable solid-state electrolytes can potentially address the reliability and energy density limitations of lithium-ion batteries. Garnet-structured oxides such as Li 7 La 3 Zr 2 O 12 (LLZO) are some of the most promising candidates for solid-state devices. Here, three-dimensional (3D) solid-state LLZO frameworks with low tortuosity pore channels are proposed as scaffolds, into which active materials and other components can be infiltrated to make composite electrodes for solid-state batteries. To make the scaffolds, we employed aqueous freeze tape casting (FTC), a scalable and environmentally friendly method to produce porous LLZO structures. Using synchrotron radiation hard X-ray microcomputed tomography, we confirmed that LLZO films with porosities of up to 75% were successfully fabricated from slurries with a relatively wide concentration range. The acicular pore size and shape at different depths of scaffolds were quantified by fitting the pore shapes with ellipses, determining the long and short axes and their ratios, and investigating the equivalent diameter distribution. The results show that relatively homogeneous pore sizes and shapes were sustained over a long range along the thickness of the scaffold. Additionally, these pores had low tortuosity and the wall thickness distributions were found to be highly homogeneous. These are desirable characteristics for 3D solid electrolytes for composite electrodes, in terms of both the ease of active material infiltration and also minimization of Li diffusion distances in electrodes. The advantages of the FTC scaffolds are demonstrated by the improved conductivity of LLZO scaffolds infiltrated with poly(ethylene oxide)/lithium bis(trifluoromethanesulfonyl)imide (PEO/LITFSI) compared to those of PEO/LiTFSI films alone or composites containing LLZO particles.

36 MATERIALS SCIENCE↗

Dry tape battery

Battery system using dry tape continuous feed of magnesium fuel

MAGNESIUM COMPOUND↗