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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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12 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

High-Voltage and High-Safety Practical Lithium Batteries with Ethylene Carbonate-Free Electrolyte

Serious safety issues are impeding the widespread adoption of high-energy lithium-ion batteries for transportation electrification and large-scale grid storage. Herein, a triple-salt ethylene carbonate (EC) free electrolyte for high-safety and high-energy pouch-type LiNi 0.8 Mn 0.1 Co 0.1 O 2 |graphite (NMC811|Gr) cells is reported. This EC-free electrolyte can effectively stabilize the NMC811 surface under high potential (up to 4.5 V), as well as generate a stable interphase to achieve a superior compatibility with the Gr anode. The electrolyte strategy enables significantly enhanced intrinsic safety (trigger temperature of thermal runaway (TR) increased by 67.0 °C), excellent electrochemical properties (4.2V, ≈100% after 200 cycles), and superior high voltage stability (4.5 V, 82.1% after 200 cycles). Furthermore, the work opens up a new avenue for developing novel electrolyte systems to build safer high-energy batteries for practical applications.

25 ENERGY STORAGE↗
DOE OSTI2021

In-built ultraconformal interphases enable high-safety practical lithium batteries

There is an urgent need for high-safety and high-energy lithium-ion batteries to satisfy the rapidly increasing need for energy storage. Nickel-rich layered cathodes have been at the forefront of the revolution for batteries due to their relatively high capacity and low cost. However, with the increase of nickel content, the batteries suffer from severe safety concerns, which caused by thermal runaway. Herein, we show that the ultraconformal cathode-electrolyte interphase (CEI) protective skin with high inorganic content dramatically enhances the safety of high-energy practical Li-ion pouch cells. We find that the robust CEI skin significantly improves the intrinsic thermal stability, mitigates the evolution of oxygen resulting from phase transition, and effectively suppresses the associated parasitic reactions between the delithiated cathodes and electrolyte. The in-situ CEI engineering strategy is simple and suitable for practical industrial manufacture, and it provides design ideas for aggressive nickel-rich cathodes towards safe and high-energy batteries.

25 ENERGY STORAGE↗
DOE OSTI2023

Solid-state interphases design for high-safety, high-voltage and long-cyclability practical batteries via ethylene carbonate-free electrolytes

In this study, ethylene carbonate (EC) plays a crucial role in current electrolytes for batteries. However, EC reacts exothermically with the electrode to trigger thermal runaway and undergoes continuous oxidative decomposition at high voltages, hindering it application for next-generation batteries. Here we report a simple and effective strategy to design sulfolane(SL)-based electrolyte with reshaped anions-dominated solvation structure, forming highly stable inorganic-dominated electrode-electrolyte interphases that efficiently stabilize nickel-rich cathode and graphite anode. Compared with the conventional electrolyte, practical pouch-type LiNi 0.8 Co 0.1 Mn 0.1 O 2 |Graphite cell with SL-based electrolyte significantly improve self-generated heat T 1 and thermal runaway triggering T 2 by 9.6 and 42.0 °C, respectively. More surprisingly, the pouch cell with SL-based electrolyte exhibits outstanding capacity retention of 88 % after 1000 cycles charged up to 4.5 V. The study brings new insights for unlocking advanced electrolyte candidates to build next-generation practical safer high-energy batteries.

25 ENERGY STORAGE↗
DOE OSTI2020

Ultralight and fire-extinguishing current collectors for high-energy and high-safety lithium-ion batteries

Inactive components and safety hazards are two critical challenges in realizing high-energy lithium-ion batteries. Metal foil current collectors with high density are typically an integrated part of lithium-ion batteries yet deliver no capacity. Meanwhile, high-energy batteries can entail increased fire safety issues. Here we report a composite current collector design that simultaneously minimizes the ‘dead weight’ within the cell and improves fire safety. An ultralight polyimide-based current collector (9 μm thick, specific mass 1.54 mg cm-2) is prepared by sandwiching a polyimide embedded with triphenyl phosphate flame retardant between two superthin Cu layers (~500 nm). Compared to lithium-ion batteries assembled with the thinnest commercial metal foil current collectors (~6 µm), batteries equipped with our composite current collectors can realize a 16-26% improvement in specific energy and rapidly self-extinguish fires under extreme conditions such as short circuits and thermal runaway.

25 ENERGY STORAGE↗
DOE OSTI2022

High-Safety Electrolytes for Lithium-Ion Batteries : Is non-flammability of electrolyte overrated in the overall safety performance of lithium ion batteries?

It has been widely considered that the flammability of the liquid electrolyte is one of the most influential factors that determine the safety of lithium ion batteries (LIBs). Following this consideration, a completely non-flammable electrolyte was designed and adopted to graphite||LiFePO 4 (Gr||LFP) batteries. Contrary to the conventional understanding, the completely non-flammable electrolyte with phosphorus-containing solvents exhibits inferior safety performance in commercial Gr||LFP batteries, in comparison to the flammable conventional LiPF 6 -organocarbonate electrolyte. Mechanistic studies identify the exothermic reactions between the electrolyte (especially the flame retarding phosphate solvent) and the charged electrodes as the “culprit” behind such a counterintuitive phenomenon. The discovery emphasizes the importance of reducing the electrolyte reactivity when designing safe electrolytes, as well as the necessity of evaluating safety performances of electrolyte on a battery level.

25 ENERGY STORAGE↗
DOE OSTI2020

Developing high safety Li-metal anodes for future high-energy Li-metal batteries: strategies and perspectives

Developing high-safety Li-metal anodes (LMAs) is extremely important for the application of high-energy Li-metal batteries (LMBs), especially Li–S and Li–O 2 battery systems. However, the notorious Li-dendrite growth problem results in serious safety concerns for any energy storage application. Through a recent combination of interface-based science, nanotechnology-based solutions and characterization methods, the LMA is now primed for a technological boom. In this review, the recent emerging strategies and perspectives on LMAs are summarized, following which the current huge evolution in interfacial chemistry regulation, optimizing electrolyte components, designing a rational ‘host’ for lithium metal, optimizing “solid-state electrolytes” and other emerging strategies for developing high-safety LMAs is highlighted. Furthermore, several state-of-the-art in situ/operando synchrotron-based X-ray techniques for high safety LMB research are introduced. With the further development of LMAs in the future, subsequent application in high energy LMBs is to be expected.

25 ENERGY STORAGE↗
DOE OSTI2023

Incombustible Polymer Electrolyte Boosting Safety of Solid–State Lithium Batteries: A Review

Lithium-ion batteries with their portability, high energy density, and reusability are frequently used in today's world. Under extreme conditions, lithium-ion batteries leak, burn, and even explode. Therefore, improving the safety of lithium-ion batteries has become a focus of attention. Researchers believe using a solid electrolyte instead of a liquid one can solve the lithium battery safety issue. Due to the low price, good processability and high safety of the solid polymer electrolytes, increasing attention have been paid to them. However, polymer electrolytes can also decompose and burn under extreme conditions. Moreover, lithium dendrites are formed continuously due to the uneven charge distribution on the surface of the lithium metal anode. A short circuit caused by a lithium dendrite can cause the battery to thermal runaway. As a result, the safety of polymer solid-state batteries remains a challenge. In this review, the thermal runaway mechanism of the batteries is summarized, and the batteries abuse test standard is introduced. In addition, the recent works on the high-safety polymer electrolytes and the solution strategies of lithium anode problems in polymer batteries are reviewed. Finally, the development direction of safe polymer solid lithium batteries is prospected.

25 ENERGY STORAGE↗
NASA NTRS1989

The role of flight planning in aircrew decision performance

The role of flight planning in increasing the safety and decision-making performance of the air transport crews was investigated in a study that involved 48 rated airline crewmembers on a B720 simulator with a model-board-based visual scene and motion cues with three degrees of freedom. The safety performance of the crews was evaluated using videotaped replays of the flight. Based on these evaluations, the crews could be divided into high- and low-safety groups. It was found that, while collecting information before flights, the high-safety crews were more concerned with information about alternative airports, especially the fuel required to get there, and were characterized by making rapid and appropriate decisions during the emergency part of the flight scenario, allowing these crews to make an early diversion to other airports. These results suggest that contingency planning that takes into account alternative courses of action enhances rapid and accurate decision-making under time pressure.

Pepitone, Dave↗
NASA NTRSDate not supplied

Design Considerations for Practical Li-S Batteries for Electric Aviation

The development of high-energy, high-safety, and high-power batteries beyond electric automotive standards is critical for future electric aviation applications. Non-volatile solid-state electrolytes (SSE) offer many promising advantages over traditional flammable liquid electrolytes. Solid-state electrolytes may be an enabling technology for certain battery chemistries by preventing detrimental interactions with liquid electrolytes, for example prevention of the dissolution of intermediates in lithium-sulfur common in traditional liquid organic solvents. However, significant manufacturing challenges must be overcome before the adoption of such technology. This research was conducted to identify processing techniques for producing solid-state battery components with practical dimensions and weights for enabling high specific energy cells. Traditional research has identified a range of very high theoretical ionic conductivities but are impractical due to their instability or inability to be manufactured. Electrolytes explored in this study were produced as sulfide-polymer composites with densified thicknesses below 40 micron using a tape-casting technique and thermoplastic elastomer binder. The combination of high chemical compatibility and flexibility produced robust films that had moderate impact on the ionic conductivity but was capable of dramatically reducing the parasitic mass. Despite minimal conductivity losses, films were produced 10-15 times thinner than comparable bulk powder electrolytes thus leading to overall lower film resistance. Conductivity is maintained above 0.2mS/cm for composite electrolytes. Through the analysis of materials based on their physical properties, such as density, practical cells can be designed. Based on this, low density sulfide-solid-state electrolytes are a promising candidate for achieving the energy and safety metrics for electric aviation, however, further optimization of cathode microstructure and composite processing will be required to achieve the high power metrics and will be the focus of further studies. Additionally, fabrication challenges arise when utilizing metallic lithium foil, due to its soft nature, as overflow and mechanical short circuit can occur on assembly which remains a challenge to overcome before metallic lithium anodes can be fully realized.

batteries↗
NASA NTRSDate not supplied

Design Considerations for Practical Li-S Battery Components for Electric Aviaiton

The development of high-energy, high-safety, and high-power batteries beyond electric automobile requirements is vital for future electric aviation applications. The transition to non-volatile solid-state electrolytes (SSE) promises many advantages over traditional flammable liquid electrolytes, and may also be an enabling technology for next generation chemistries. However, significant manufacturing challenges must be overcome before the adoption of such technology. Electrolytes developed in this study were produced as sulfide-polymer composites with densified thicknesses between 20-30 microns using a tape-casting technique and elastomer binder [1]. The composites were determined to retain reasonable ionic conductivity with improved flexibility and scalability critical for practical manufacturing of such cells. Films were produced 10-15 times thinner than comparable bulk powder electrolytes and within the range of commercial polyolefin separators (25 micron) used in commercial liquid containing lithium-ion cells. Composite conductivities were maintained above 0.2mS/cm, which holds promise for future electric aviation applications. Processing techniques are investigated to further improve electrochemical performance.

battery↗
NASA NTRSDate not supplied

Fabrication of Solid-State Li-S Battery Components for Electric Aviation

The development of high-energy, high-safety, and high-power batteries beyond electric automobile requirements is vital for future electric aviation applications. The transition to non-volatile solid-state electrolytes (SSE) promises many advantages over traditional flammable liquid electrolytes, and may also be an enabling technology for next generation chemistries. However, significant manufacturing challenges must be overcome before the adoption of such technology. Electrolytes developed in this study were produced as sulfide-polymer composites with densified thicknesses between 20-30 microns using several processing techniques [1]. Ionic conductivity and lithium metal compatibility for the composites were compared and shown to retain reasonable ionic conductivity with improved flexibility and scalability which identifies a critical path for the production of practical solid-state batteries. Films were produced 10-15 times thinner than comparable bulk cold pressed powder electrolytes and achieved thicknesses comparable to commercial polyolefin separators (25 micron) used in commercial liquid containing lithium-ion cells. Composite conductivities were maintained above 0.2mS/cm, which holds promise for future electric aviation applications. Processing techniques are investigated to further improve electrochemical performance.

battery↗