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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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Argyrodite-Li 6 PS 5 Cl/Polymer-based Highly Conductive Composite Electrolyte for All-Solid-State Batteries
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In Situ Synthesis of Phosphate-Based CelloMOF as a Promising Separator for Li–Ion Batteries
Nowadays, battery separators play a critical role in determining the sustainability, electrochemical efficiency, and safety of lithium-ion batteries (LIBs). In this contribution, we developed fire-resistant composite membranes called CelloMOF by in situ grafting of metal-organic framework, ZIF-67, onto phosphorylated cellulose nanofibers (P-CNFs) followed by a vacuum filtration process akin to papermaking. The hybrid ZIF-67@P-CNF membrane exhibits superior properties than a polyolefin-based commercial separator (CS) in terms of enhanced thermal and dimensional stability, flame-retardant properties, better surface wettability, and improved electrolyte uptake. Thermal dimensional stability tests revealed that the ZIF-67@P-CNF separator maintained its structure even at 200 °C, whereas CS suffered severe shrinkage, potentially leading to internal short circuits. Combustion tests showed a peak heat release rate (PHRR) of 34.5 W/g and a total heat release (THR) of 1.61 kJ/g for ZIF-67@P-CNF, significantly lower than the PHRR (1111.82 W/g) and THR (40.89 kJ/g) of CS. The composite separator also demonstrated significantly improved wettability, with a contact angle of 32 ± 1.04°, compared to 92 ± 1.07° for CS, highlighting its hydrophilic nature. Electrochemical evaluations in LiFePO 4 /Li half-cells indicated a higher discharge capacity of 149 mA h g -1 at 0.2 C and superior capacity retention of 86% after 50 cycles, outperforming CS (145 mA h g -1 and 84%, respectively). In conclusion, these results underscore the potential of the ZIF-67@P-CNF membrane to advance safe, high-performance LIBs by addressing critical challenges in thermal stability, flame retardancy, and electrolyte compatibility.
Unveiling the lithium-ion transport mechanism in Li{sub 2}ZrCl{sub 6} Solid-State Electrolyte {ital via} deep learning-accelerated molecular dynamics simulations.
Lithium zirconium chlorides (LZCs) present a promising class of cost-effective solid electrolytes for next-generation all-solid-state batteries. The unique crystal structure of LZCs plays a crucial role in facilitating lithium-ion mobility, which further affects the electrochemical performance. To understand the underlying mechanism governing ion transport, we employed deep learning-accelerated molecular dynamics simulation on Li2ZrCl6 (trigonal alpha- and monoclinic beta-LZC), focusing specifically on the zirconium coordination environment. Our results reveal that disordered alpha-LZC exhibits the highest ionic conductivity, while beta-LZC demonstrates significantly lower conductivity, closely aligning with experimental findings. The study confirms that across all phases, lithium migration proceeds via the site-to-site hopping mechanism, where variations in site residence times critically impact the overall ionic conductivity. In alpha-LZCs, lithium ions prefer to anisotropically diffuse across interlayers as the result of a lower energy barrier, driven primarily by collective diffusion. In contrast, lithium ions in beta-LZC primarily isotropically diffuse within the intralayer, hindered by higher energy barriers and determined by individual diffusion. The variation in ZrCl6 2- octahedral unit softening, induced by the specific layered arrangement of zirconium atoms, emerges as a critical determinant of the energy barriers across the LZC phases. These atomic-scale insights into the transport processes provide valuable guidance for the rational design and optimization of LZCs-based electrolytes, accelerating their practical application in advanced energy storage technologies.
Microwave Processed, Onion-like Carbon and Fluoropolymer Passivated Lithium Metal Electrode for Enhanced Li Stripping/Plating Performance
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Complementary Electrolyte Design for Li Metal Batteries in Electric Vehicle Applications
In this report a complementary electrolyte system with 0.8 M lithium bis(fluorosulfonylimide) (LiFSI) salt and 2 wt % lithium perchlorate (LiCLO4) additive in fluoroethylene carbonate (FEC)/ethyl methyl carbonate (EMC) solution enables not only stable cycling of lithium metal batteries (LMBs) with practical loading (<30 μm lithium anode, cathode loading > 4 mAh/cm 2 ) but also outstanding degradation stability toward the end of cycle life when compared to the conventional electrolyte. Although the use of LiFSI salt can increase the electrolyte conductivity and lengthen the cycle life of LMBs, the aged lithium anode morphology formed by the sacrificial decomposition of LiFSI is highly porous, leading to an abrupt cell capacity drop toward the end of cycling. Moreover, the inability to stop aluminum corrosion by the LiFSI-based electrolyte also causes cracking of the cathode tab during prolonged cycling. It is observed that a highly porous aged lithium consumed electrolyte at a higher rate, leading to the dry-out of electrolyte solvents. On the contrary, dense aged lithium anode morphology increased the localized current applied on the lithium, causing the formation of lithium dendrite. Thus, porosity control is the key to enhance battery performance. In this complementary system, LiClO 4 was introduced as an advanced additive to not only improve the capacity retention rate but also mitigate the abrupt capacity drop toward the end of cycle life because LiClO 4 acted as a pore astringent reducing the porosity of the aged lithium metal anode to the desired level. Moreover, the addition of LiClO 4 can also suppress the AI corrosion, allowing stable high-voltage cycling of LMBs. The synergistic effect of combining LiFSI salt and a LiClO 4 additive leads to an electrolyte system that can facilitate the application of high-energy LMBs with practical electrode loading.
Subtle Local Structural Details Influence Ion Transport in Glassy Li[superscript +] Thiophosphate So
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Ion–Solvent Interplay in Concentrated Electrolytes Enables Subzero Temperature Li-Ion Battery Operations
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Functionalized Silicon Particles for Enhanced Half- and Full-Cell Cycling of Si-Based Li-Ion Batteries
Vinylene carbonate (VC) and polyethylene oxide (PEO) have been investigated as functional agents that mimic the solid electrolyte interphase (SEI) chemistry of silicon (Si). VC and PEO are known to contribute to the stability of Si-based lithium-ion batteries as an electrolyte additive and as a SEI component, respectively. In this work, covalent surface functionalization was achieved via a facile route, which involves ball-milling the Si particles with sacrificial VC and PEO. Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy indicate that the additives are strongly bound to Si. In particular, MAS NMR shows Si–R or Si–O–R groups, which confirm functionalization of the Si after milling in VC or PEO. Particle size analysis by dynamic light scattering reveals that the additives facilitate particle size reduction and that the functionalized particles result in more stable dispersions based on zeta potential measurements. Raman mapping of the electrodes fabricated from the VC and PEO-coated active material with a polyacrylic acid (PAA) binder reveals a more homogenous distribution of Si and the carbon conductive additive compared to the electrodes prepared from the neat Si. Furthermore, the VC-milled Si strikingly exhibited the highest capacity in both half- and full-cell configurations, with more than 200 mAh g –1 measured capacity compared to the neat Si in the half-cell format. This is linked to an improved electrode processing based on the Raman and zeta potential measurements as well as a thinner SEI (with more organic components for the functionalized Si relative to the neat Si) based on XPS analysis of the cycled electrodes. In conclusion, the effect of binder was also investigated by comparing PAA with P84 (polyimide type), where an increased capacity is observed in the latter case.
Nano-FTIR Spectroscopy of the Solid Electrolyte Interphase Layer on a Thin-Film Silicon Li-Ion Anode
Not Available
Lithium Phosphorus Sulfide Chloride–Polymer Composite via the Solution–Precipitation Process for Improving Stability toward Dendrite Formation of Li-Ion Solid Electrolyte
Not Available
Promoting a Stable Interface Using Localized High-Concentration Carbonate-Based Electrolyte for Li Metal Batteries
Not provided.