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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 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Accurate Determination of the Quantity and Spatial Distribution of Counterions around a Spherical Macroion

Abstract The accurate distribution of countercations (Rb + and Sr 2+ ) around a rigid, spherical, 2.9‐nm size polyoxometalate cluster, {Mo 132 } 42− , is determined by anomalous small‐angle X‐ray scattering. Both Rb + and Sr 2+ ions lead to shorter diffuse lengths for {Mo 132 } than prediction. Most Rb + ions are closely associated with {Mo 132 } by staying near the skeleton of {Mo 132 } or in the Stern layer, whereas more Sr 2+ ions loosely associate with {Mo 132 } in the diffuse layer. The stronger affinity of Rb + ions towards {Mo 132 } than that of Sr 2+ ions explains the anomalous lower critical coagulation concentration of {Mo 132 } with Rb + compared to Sr 2+ . The anomalous behavior of {Mo 132 } can be attributed to majority of negative charges being located at the inner surface of its cavity. The longer anion–cation distance weakens the Coulomb interaction, making the enthalpy change owing to the breakage of hydration layers of cations more important in regulating the counterion–{Mo 132 } interaction.

Chen, Jiahui↗
DOE OSTI2022

A Facile Potential Hold Method for Fostering an Inorganic Solid‐Electrolyte Interphase for Anode‐Free Lithium‐Metal Batteries

Abstract Anode‐free lithium batteries are regarded as an ultimate form of high‐energy‐density lithium‐ion batteries. Unfortunately, irreversible lithium loss during cycling plays a major role in degrading the overall cell performance in the anode‐free configuration. To alleviate the deterioration, building a robust solid‐electrolyte interface on an anode current collector is an indispensable requirement. Here, we present a facile in‐situ electrochemical method of a potential hold during the first charge to guide more salt‐derived (less solvent‐derived) decomposition on the anode interface. We show the distinctive decomposition potential of lithium salts and ether/carbonate solvents, where the Li‐solvation structures with salt contact‐ion‐pairs preferentially decompose to form LiF‐rich and less organic components, leading to enhanced lithium Coulombic efficiency in Li||Cu cells as well as mitigating the capacity fade of Cu||LiFePO 4 and Cu||LiNi 0.8 Mn 0.1 Co 0.1 O 2 cells.

Shin, Woochul↗
DOE OSTI2022

Pushing Lithium–Sulfur Batteries towards Practical Working Conditions through a Cathode–Electrolyte Synergy

Abstract The commercialization of lithium–sulfur (Li−S) batteries is still hindered by the unsatisfactory cell performance under practical working conditions, which is mainly caused by the sluggish cathode redox kinetics, severe polysulfide shuttling, and poor Li stripping/plating reversibility. Herein, we report an effective strategy by combining Se‐doped S hosted in an ordered macroporous framework with a highly fluorinated ether (HFE)‐based electrolyte to simultaneously address the aforementioned issues in both cathode and anode. A reversible and stable high areal capacity of >5.4 mAh cm −2 with high Coulombic efficiency >99.2 % can be achieved under high areal Se/S loading (5.8 mg cm −2 ), while the underlying mechanism was further revealed through synchrotron X‐ray probes and Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS). The practical application potential was further evaluated at low (0 °C) and high (55 °C) temperatures under high areal Se/S loading (>5.0 mg cm −2 ) and thin Li metal (40 μm).

Zhao, Chen↗
DOE OSTI2022

A Carboranyl Electrolyte Enabling Highly Reversible Sodium Metal Anodes via a “Fluorine‐Free” SEI

Abstract Realization of practical sodium metal batteries (SMBs) is hindered due to lack of compatible electrolyte components, dendrite propagation, and poor understanding of anodic interphasial chemistries. Chemically robust liquid electrolytes that facilitate both favorable sodium metal deposition and a stable solid‐electrolyte interphase (SEI) are ideal to enable sodium metal and anode‐free cells. Herein we present advanced characterization of a novel fluorine‐free electrolyte utilizing the [HCB 11 H 11 ] 1− anion. Symmetrical Na cells operated with this electrolyte exhibit a remarkably low overpotential of 0.032 V at a current density of 2.0 mA cm −2 and a high coulombic efficiency of 99.5 % in half‐cell configurations. Surface characterization of electrodes post‐operation reveals the absence of dendritic sodium nucleation and a surprisingly stable fluorine‐free SEI. Furthermore, weak ion‐pairing is identified as key towards the successful development of fluorine‐free sodium electrolytes.

Tomich, Anton W.↗
DOE OSTI2023

High‐Performance Lithium Metal Batteries Enabled by a Fluorinated Cyclic Ether with a Low Reduction Potential

Abstract Electrolyte engineering is crucial for developing high‐performance lithium metal batteries (LMB). Here, we synthesized two cosolvents methyl bis(fluorosulfonyl)imide (MFSI) and 3,3,4,4‐tetrafluorotetrahydrofuran (TFF) with significantly different reduction potentials and add them into LiFSI‐DME electrolytes. The LiFSI/TFF‐DME electrolyte gave an average Li Coulombic efficiency (CE) of 99.41 % over 200 cycles, while the average Li CEs for MFSI‐based electrolyte is only 98.62 %. Additionally, the TFF‐based electrolytes exhibited a more reversible performance than the state‐of‐the‐art fluorinated 1,4‐dimethoxylbutane electrolyte in both Li||Cu half‐cell and anode‐free Cu||LiNi 0.8 Mn 0.1 Co 0.1 O 2 full cell. More importantly, the decomposition product from bis(fluorosulfonyl)imide anion could react with ether solvent, which destroyed the SEI, thus decreasing cell performance. These key discoveries provide new insights into the rational design of electrolyte solvents and cosolvents for LMB.

Wu, Min↗
DOE OSTI2024

Oxygen‐Assisted Supercapacitive Swing Adsorption of Carbon Dioxide

Abstract We report on the supercapacitive swing adsorption (SSA) of carbon dioxide at different voltage windows in the presence of oxygen using activated carbon electrodes, and deliquescent, aqueous electrolytes. The presence of O 2 in the CO 2 /N 2 gas mixture results in an up to 11 times higher CO 2 adsorption capacity with 3 M MgBr 2 (at 0.6 V) and up to 4–5 times higher adsorption capacity with 3 M MgCl 2 (at 1 V). A tradeoff between high CO 2 adsorption capacities and lower coulombic efficiencies was observed at voltages above 0.6 V. The energetic and adsorptive performance of the electrodes in the presence of oxygen below 0.5 V was similar to the performance with a CO 2 /N 2 mixture without oxygen at 1 V. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) of the electrodes demonstrate that the specific capacitance increases while the diffusion resistance decreases in the presence of oxygen. Oxygen concentrations ranging between 5–20 % give similar energetic and adsorptive performance. The electrodes exhibit stable performance for up to 100 cycles of operation.

Bilal, Muhammad↗
DOE OSTI2020

Beyond the Polysulfide Shuttle and Lithium Dendrite Formation: Addressing the Sluggish Sulfur Redox Kinetics for Practical High-Energy Li-S Batteries

Electrolyte modulation simultaneously suppresses polysulfide the shuttle effect and lithium dendrite formation of lithium-sulfur (Li-S) batteries. However, the sluggish S redox kinetics, especially under high S loading and lean electrolyte operation, has been ignored, which dramatically limits the cycle life and energy density of practical Li-S pouch cells. In this work, we demonstrate that a rational combination of selenium doping, core-shell hollow host structure, and fluorinated ether electrolytes enables ultrastable Li stripping/plating and essentially no polysulfide shuttle as well as fast redox kinetics. Thus, high areal capacity (>4 mAh cm -2 ) with excellent cycle stability and Coulombic efficiency were both demonstrated in Li metal anode and thick S cathode (4.5 mg cm -2 ) with a low electrolyte/sulfur ratio (10 mu L mg(-1)). Overall, this research further demonstrates a durable Li-Se/S pouch cell with high specific capacity, validating the potential practical applications.

25 ENERGY STORAGE↗
DOE OSTI2022

A Facile Potential Hold Method for Fostering an Inorganic Solid-Electrolyte Interphase for Anode-Free Lithium-Metal Batteries

Anode-free lithium batteries are regarded as an ultimate form of high-energy-density lithium-ion batteries. Unfortunately, irreversible lithium loss during cycling plays a major role in degrading the overall cell performance in the anode-free configuration. To alleviate the deterioration, building a robust solid-electrolyte interface on an anode current collector is an indispensable requirement. Here, we present a facile in-situ electrochemical method of a potential hold during the first charge to guide more salt-derived (less solvent-derived) decomposition on the anode interface. Here we show the distinctive decomposition potential of lithium salts and ether/carbonate solvents, where the Li-solvation structures with salt contact-ion-pairs preferentially decompose to form LiF-rich and less organic components, leading to enhanced lithium Coulombic efficiency in Li||Cu cells as well as mitigating the capacity fade of Cu||LiFePO 4 and Cu||LiNi 0.8 Mn 0.1 Co 0.1 O 2 cells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Ultrafast Metal Electrodeposition Revealed by In Situ Optical Imaging and Theoretical Modeling towards Fast–Charging Zn Battery Chemistry

Metallic Zn is a preferred anode material for rechargeable aqueous batteries towards a smart grid and renewable energy storage. Importantly, understanding how the metal nucleates and grows at the aqueous Zn anode is a critical and challenging step to achieve full reversibility of Zn battery chemistry, especially under fast-charging conditions. Here, by combining in situ optical imaging and theoretical modeling, we uncover the critical parameters governing the electrodeposition stability of the metallic Zn electrode, that is, the competition among crystallographic thermodynamics, kinetics, and Zn 2+ -ion diffusion. Moreover, steady-state Zn metal plating/ stripping with Coulombic efficiency above 99 % is achieved at 10-100 mA cm -2 in a reasonably high concentration (3 M) ZnSO 4 electrolyte. Significantly, a long-term cycling-stable Zn metal electrode is realized with a depth of discharge of 66.7% under 50 mA cm -2 in both Zn || Zn symmetrical cells and MnO 2 || Zn full cells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Pushing Lithium–Sulfur Batteries towards Practical Working Conditions through a Cathode–Electrolyte Synergy

The commercialization of lithium-sulfur (Li-S) batteries is still hindered by the unsatisfactory cell performance under practical working conditions, which is mainly caused by the sluggish cathode redox kinetics, severe polysulfide shuttling, and poor Li striping/platting reversibility. We reported an effective strategy by combining Se-doped S hosted in an ordered macroporous framework with highly fluorinated ether (HFE)-based electrolyte to simultaneously address the aforementioned issues in both cathode and anode. A reversible and stable high areal capacity of > 5.4 mAh cm -2 with high coulombic efficiency > 99.2% can be achieved under high areal Se/S loading (5.8 mg cm -2 ), while the underlying mechanism was further revealed through synchrotron X-ray probes and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The practical application potential was further evaluated at low (0 °C) and high (55 °C) temperatures under high areal Se/S loading (> 5.0 mg cm -2 ) and thin Li metal (40 µm).

25 ENERGY STORAGE↗
DOE OSTI2022

A Carboranyl Electrolyte Enabling Highly Reversible Sodium Metal Anodes via a “Fluorine-Free” SEI

Realization of practical sodium metal batteries (SMBs) is hindered due to lack of compatible electrolyte components, dendrite propagation, and poor understanding of anodic interphasial chemistries. Chemically robust liquid electrolytes that facilitate both favorable sodium metal deposition and a stable solid-electrolyte interphase (SEI) are ideal to enable sodium metal and anode-free cells. Herein we present advanced characterization of a novel fluorine-free electrolyte utilizing the [HCB 11 H 11 ] 1- anion. Symmetrical Na cells operated with this electrolyte exhibit a remarkably low overpotential of 0.032 V at a current density of 2.0 mA cm -2 and a high coulombic efficiency of 99.5 % in half-cell configurations. Additionally, surface characterization of electrodes post-operation reveals the absence of dendritic sodium nucleation and a surprisingly stable fluorine-free SEI. Furthermore, weak ion-pairing is identified as key towards the successful development of fluorine-free sodium electrolytes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

High‐Performance Lithium Metal Batteries Enabled by a Fluorinated Cyclic Ether with a Low Reduction Potential

Abstract Electrolyte engineering is crucial for developing high‐performance lithium metal batteries (LMB). Here, we synthesized two cosolvents methyl bis(fluorosulfonyl)imide (MFSI) and 3,3,4,4‐tetrafluorotetrahydrofuran (TFF) with significantly different reduction potentials and add them into LiFSI‐DME electrolytes. The LiFSI/TFF‐DME electrolyte gave an average Li Coulombic efficiency (CE) of 99.41 % over 200 cycles, while the average Li CEs for MFSI‐based electrolyte is only 98.62 %. Additionally, the TFF‐based electrolytes exhibited a more reversible performance than the state‐of‐the‐art fluorinated 1,4‐dimethoxylbutane electrolyte in both Li||Cu half‐cell and anode‐free Cu||LiNi 0.8 Mn 0.1 Co 0.1 O 2 full cell. More importantly, the decomposition product from bis(fluorosulfonyl)imide anion could react with ether solvent, which destroyed the SEI, thus decreasing cell performance. These key discoveries provide new insights into the rational design of electrolyte solvents and cosolvents for LMB.

25 ENERGY STORAGE↗
DOE OSTI2023

Implanting Transition Metal into Li 2 O-Based Cathode Prelithiation Agent for High-Energy-Density and Long-Life Li-Ion Batteries

Compensating the irreversible loss of limited active lithium (Li) is essentially important for improving the energy-density and cycle-life of practical Li-ion battery full-cell, especially after employing high-capacity but low initial coulombic efficiency anode candidates. Introducing prelithiation agent can provide additional Li source for such compensation. Herein, we precisely implant trace Co (extracted from transition metal oxide) into the Li site of Li 2 O, obtaining (Li 0.66 Co 0.11$\square$0.23 ) 2 O (CLO) cathode prelithiation agent. Further, the synergistic formation of Li vacancies and Co-derived catalysis efficiently enhance the inherent conductivity and weaken the Li-O interaction of Li 2 O, which facilitates its anionic oxidation to peroxo/superoxo species and gaseous O 2 , achieving 1642.7 mAh/g ~Li2O prelithiation capacity (≈980 mAh/g for prelithiation agent). Coupled 6.5 wt % CLO-based prelithiation agent with LiCoO 2 cathode, substantial additional Li source stored within CLO is efficiently released to compensate the Li consumption on the SiO/C anode, achieving 270 Wh/kg pouch-type full-cell with 92 % capacity retention after 1000 cycles.

25 ENERGY STORAGE↗
DOE OSTI2024

Oxygen‐Assisted Supercapacitive Swing Adsorption of Carbon Dioxide

We report on the supercapacitive swing adsorption (SSA) of carbon dioxide at different voltage windows in the presence of oxygen using activated carbon electrodes, and deliquescent, aqueous electrolytes. The presence of O 2 in the CO 2 /N 2 gas mixture results in an up to 11 times higher CO 2 adsorption capacity with 3 M MgBr 2 (at 0.6 V) and up to 4–5 times higher adsorption capacity with 3 M MgCl 2 (at 1 V). A tradeoff between high CO 2 adsorption capacities and lower coulombic efficiencies was observed at voltages above 0.6 V. The energetic and adsorptive performance of the electrodes in the presence of oxygen below 0.5 V was similar to the performance with a CO 2 /N 2 mixture without oxygen at 1 V. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) of the electrodes demonstrate that the specific capacitance increases while the diffusion resistance decreases in the presence of oxygen. Oxygen concentrations ranging between 5–20 % give similar energetic and adsorptive performance. The electrodes exhibit stable performance for up to 100 cycles of operation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Surface Vacancy Engineering Re-Routes First-Cycle Redox for Stabilized Li-Rich Layered Cathodes

We demonstrate that atomic-scale surface disorder can control the first-cycle redox sequence of Li-rich layered oxides, eliminating the detrimental process of oxygen release and lattice collapse that degrades performance. In Li1.14Ni0.32Mn0.54O2 (LNMO), a simple chemical treatment introduces oxygen and transition metal (TM) vacancies confined to the particle surface while preserving the bulk layered framework. Multi-modal synchrotron analyses reveal that these vacancies trigger an early oxygen oxidation below 4.4 V, delay nickel oxidation to higher potential, and suppress the formation of covalent Ni4+─O states. This modified pathway prevents irreversible oxygen release, suppresses manganese dissolution, and maintains metal-oxygen coordination at high voltages. Consequently, the treated cathode delivers higher first-cycle Coulombic efficiency (CE), mitigated voltage fade, and superior capacity retention. By directly linking engineered surface disorder to redox reactions and associated structural transformations, this work establishes a general design principle for durable, high-energy-density cathodes.

Kang, Seongkoo↗
DOE OSTI2026

Heat Transfer Fluids as Co‐Diluents in Localized High‐Concentration Electrolytes for High‐Rate Lithium Metal Batteries With Enhanced Safety

Localized high-concentration electrolytes (LHCEs) have been identified as promising electrolyte formulations for lithium metal batteries, due to their effective interphase formation and promotion of compact Li deposition, yet their practical implementation is often limited by reduced ion transport kinetics. In this study, two industrially established fluorinated ethers are identified for the first time in battery research as effective co-diluents as they combine a broad electrochemical stability window with a low viscosity and intrinsic non-flammability. Incorporating these components, commonly used as heat transfer fluids, yields safer, less flammable electrolyte formulations with enhanced ion mobilities. In particular, the ternary co-diluent formulation shows improved ion mobility by reducing the electrolyte's viscosity while limiting excessive ion clustering. Based on the improved electrolyte transport kinetics, lower overvoltages and higher Coulombic efficiencies at current densities ≥ 1 mA cm −2 are achieved with the ternary co-diluent blend, resulting in markedly extended cycle life in an application-oriented zero-excess pouch cell compared with the baseline system. Complementary electrochemical and ex situ analysis of harvested electrodes at moderate current densities reveals no discernible differences in interphase morphology and composition, suggesting enhanced ion mobility as the primary cause of the improved high-rate performance.

electrolyte diluent↗