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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Understanding the Impact of a Nonafluorinated Ether-Based Electrolyte on Li-S Battery

The impact of the electrolyte solvation structure on the performance of Li-S battery was investigated using an electrolyte system containing various solvent ratios of DOL and a nonafluorinated ether: 1,1,2,2-tetrafluoroethyl-2,2,3,3,3-pentafluoropropyl ether (TPE). The cell testing results indicate that increasing the TPE ratio led to both a higher discharge capacity and a higher Coulombic efficiency. The Li electrodes from the Li/Li symmetric cells showed that the one in higher TPE-content electrolyte has a smoother and more continuous SEI layer. AIMD simulation revealed the solvation structure of DOL/TPE - lithium polysulfide changes when the TPE concentration increases, which dictates the lithium polysulfide solubility in such electrolyte. These results shed light on the underpinned mechanism of the improved Coulombic efficiency and cycling performance of the Li-S cell.

25 ENERGY STORAGE↗
DOE OSTI2015

Nanotubes within transition metal silicate hollow spheres: Facile preparation and superior lithium storage performances

Highlights: • The hollow Co{sub 2}SiO{sub 4}, MnSiO{sub 3} and CuSiO{sub 3} were successfully prepared by a facile hydrothermal method using SiO{sub 2} nanosphere. • The hollow Co{sub 2}SiO{sub 4}, MnSiO{sub 3} and CuSiO{sub 3} were tested as anode materials for lithium batteries. • The hollow Co{sub 2}SiO{sub 4}, MnSiO{sub 3} and CuSiO{sub 3} delivered superior electrochemical performance. • The lithium storage mechanism is probe via cyclic voltammetry and XPS. - Abstract: A series of transition metal silicate hollow spheres, including cobalt silicate (Co{sub 2}SiO{sub 4}), manganese silicate (MnSiO{sub 3}) and copper silicate (CuSiO{sub 3}.2H{sub 2}O, CuSiO{sub 3} as abbreviation in the text) were prepared via a simple and economic hydrothermal method by using silica spheres as chemical template. Time-dependent experiments confirmed that the resultants formed a novel type of hierarchical structure, hollow spheres assembled by numerous one-dimensional (1D) nanotubes building blocks. For the first time, the transition metal silicate hollow spheres were characterized as novel anode materials of Li-ion battery, which presented superior lithium storage capacities, cycle performance and rate performance. The 1D nanotubes assembly and hollow interior endow this kind of material facilitate fast lithium ion and electron transport and accommodate the big volume change during the conversion reactions. Our study shows that low-cost transition metal silicate with rationally designed nanostructures can be promising anode materials for high capacity lithium-ion battery.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2019

High-Rate Cycling of Lithium-Metal Batteries Enabled by Dual-Salt Electrolyte-Assisted Micropatterned Interfaces

We present a synergistic strategy to boost the cycling performance of Li-metal batteries. The strategy is based on the combined use of a micro-pattern (MP) on the surface of the Li-metal electrode and an advanced dual-salt electrolyte (DSE) system to more efficiently control undesired Li-metal deposition at higher current density (~3 mA cm-2). The MP-Li electrode induces spatially uniform current distribution to achieve dendrite-free Li-metal deposition beneath the surface layer formed by the DSE. The MP-Li/DSE combination exhibited excellent synergistic rate capability improvements that were neither observed with the MP-Li system nor for the bare Li/DSE system. The combination also resulted in the Li||LiMn2O4 battery attaining over 1,000 cycles, which is twice as long at the same capacity retention (80 %) compared with the control cells (MP-Li without DSE). We further demonstrated extremely fast charging at a rate of 15 C (19.5 mA cm-2).

Yoon, Byeolhee↗
DOE OSTI2020

Enabling Highly Stable Li–O 2 Batteries with Full Discharge–Charge Capability: The Porous Binder- and Carbon-Free IrNi Nanosheet Cathode

Rechargeable aprotic Li-O 2 batteries have drawn much attention in light of their ultrahigh theoretical energy density. However, the sluggish kinetics of oxygen cathode reactions lead to huge energy loss, while the unfavorable side reactions associated with the widely used carbon and binder account for fast battery decay during cycles. In this work, hierarchically holey IrNi alloy nanosheets are facilely designed on Ni foam substrate as a freestanding, binder- and carbon-free cathode to address these challenges. The IrNi nanosheets consist of numerous interconnected nanoparticles, forming abundant nanoholes, benefiting active-site exposure. Moreover, the meso-/macropores pave channels for the transfer of oxygen and lithium ions and provide enough accommodation for the insoluble Li 2 O 2 product. The corresponding Li-O 2 batteries demonstrate low polarization and excellent cycle stability with full discharge/charge capability (up to 292 cycles at a current density of 0.2 mA cm -2 within a voltage range from 2.3 to 4.3 V). The long-term cycling performance is principally attributed to the exclusive catalytic stability of the holey IrNi nanosheets and its good compatibility with dimethyl sulfoxide-based electrolyte. Our research provides novel insights into the design of robust and freestanding porous cathodes for high energy density Li-O 2 batteries.

25 ENERGY STORAGE↗
DOE OSTI2018

Electrochemical Performance of NaFeFe(CN) 6 Prepared by Solid Reaction for Sodium Ion Batteries

Commercially available Na 4 Fe(CN) 6 and Fe 4 [Fe(CN) 6 ] 3 are two cheap compounds that have ever been investigated as positive electrode materials for sodium-ion batteries. However, poor electronic conductivity of Na 4 Fe(CN) 6 and sodium deficiency of Fe 4 [Fe(CN) 6 ] 3 prevent these two materials from being used in practical rechargeable sodium-ion batteries. In this paper, a NaFeFe(CN) 6 cathode material was synthesized by ball milling the Fe 4 [Fe(CN) 6 ] 3 / Na 4 Fe(CN) 6 mixture. The obtained NaFeFe(CN) 6 demonstrated a single cubic phase indexed to Fm3m space group similar to Fe 4 [Fe(CN) 6 ] 3 but with larger lattice parameter due to the existence of Na + in the lattice framework. The NaFeFe(CN) 6 electrode delivered first desodiation capacity of 119.4 mAh g -1 and first sodiation capacity of 153.6 mAh g -1 at 0.05C rate. The NaFeFe(CN) 6 showed excellent cycling stability with reversible capacities of 118.2 mAh g -1 and 96.8 mAh g -1 at 0.1C and 1C rate, respectively. In-situ XRD analyses demonstrated a single cubic phase process during charge-discharge of NaFeFe(CN) 6 electrode. Low water content benefited from the solid reaction method and the homogenous single phase process during charge/discharge assured the stable long term cycling performance of the NaFeFe(CN) 6 product.

25 ENERGY STORAGE↗
DOE OSTI2014

High-energy X-ray powder diffraction and atomic-pair distribution-function studies of charged/discharged structures in carbon-hybridized Li2MnSiO4 nanoparticles as a cathode material for lithiumion batteries

The stable cycling performance with a high discharge capacity of similar to 190 mAh g(-1) in a carbon-hybridized Li2MnSiO4 nanostructured powder has prompted an experimental investigation of the charged/discharged structures using synchrotron-based and laboratory-based X-rays and atomic-pair distributionfunction (PDF) analyses. A novel method of in-situ spray pyrolysis of a precursor solution with glucose as a carbon source enabled the successful synthesis of the carbon-hybridized Li2(M)nSiO(4) nanoparticles. The XRD patters of the discharged (lithiated) samples exhibit a long-range ordered structure characteristic of the (beta) Li2MnSiO4 crystalline phase (space group Pmn2(1)) which dissipates in the charged (delithiated) samples. However, upon discharging the long-range ordered structure recovers in each cycle. The disordered structure, according to the PDF analysis, is mainly due to local distortions of the MnO4 tetrahedra which show a mean Mn-O nearest neighbor distance shorter than that of the long-range ordered phase. These results corroborate the notion of the smaller Mn3+/Mn4+ ionic radii in the Li extracted phase versus the larger Mn2+ ionic radius in Li inserted phase. Thus Li extraction/insertion drives the fluctuation between the disordered and the long-range ordered structures. (C) 2014 Elsevier B.V. All rights reserved.

Atomic pair distribution function↗
DOE OSTI2020

Highly reversible oxygen redox in layered compounds enabled by surface polyanions

Oxygen-anion redox in lithium-rich layered oxides can boost the capacity of lithium-ion battery cathodes. However, the over-oxidation of oxygen at highly charged states aggravates irreversible structure changes and deteriorates cycle performance. Here, we investigate the mechanism of surface degradation caused by oxygen oxidation and the kinetics of surface reconstruction. Considering Li 2 MnO 3 , we show through density functional theory calculations that a high energy orbital (lO 2p’ ) at under-coordinated surface oxygen prefers over-oxidation over bulk oxygen, and that surface oxygen release is then kinetically favored during charging. We use a simple strategy of turning under-coordinated surface oxygen into polyanionic (SO 4 ) 2- , and show that these groups stabilize the surface of Li 2 MnO 3 by depressing gas release and side reactions with the electrolyte. Experimental validation on Li 1.2 Ni 0.2 Mn 0.6 O 2 shows that sulfur deposition enhances stability of the cathode with 99.0% capacity remaining (194 mA h g -1 ) after 100 cycles at 1 C. Our work reveals a promising surface treatment to address the instability of highly charged layered cathode materials.

25 ENERGY STORAGE↗
DOE OSTI2024

Rapid Electrochemical Diagnosis of Battery Health and Safety from Cells to Modules

Rapid electrochemical diagnosis of battery health and failure is critical for ensuring reliable battery performance and battery safety. Traditional battery health diagnostics such as capacity measurements and DC pulse tests are reliable and well-understood, however, these measurements of battery capacity and resistance do not capture all aspects of battery degradation. Other aspects of degradation, such as electrolyte decomposition, lithium-plating, and particle cracking are difficult to detect electrochemically but are crucial to measure to get a full picture of battery safety and flag out potential failures. In this work, lab- and field-aged commercial lithium-ion batteries and modules of various chemistries and formats are tested using a variety of traditional electrochemical characterization methods as well as using 2-minute pseudo-random DC pulse sequences at rest and during charge/discharge. The electrochemical measurements are compared to physical cell measurements, cell efficiency, drive cycle performance, physical and thermal heterogeneity, and qualitative safety metrics using statistical and machine-learning methods to discover if a comprehensive "battery health map" can be accurately identified using only rapid DC measurements.

ADVANCED PROPULSION SYSTEMS,ENERGY STORAGE↗
DOE OSTI2021

Layered Heterostructure Ionogel Electrolytes for High‐Performance Solid‐State Lithium‐Ion Batteries

Abstract Ionogel electrolytes based on ionic liquids and gelling matrices offer several advantages for solid‐state lithium‐ion batteries, including nonflammability, wide processing compatibility, and favorable electrochemical and thermal properties. However, the absence of ionic liquids that are concurrently stable at low and high potentials constrains the electrochemical windows of ionogel electrolytes and thus their high‐energy‐density applications. Here, ionogel electrolytes with a layered heterostructure are introduced, combining high‐potential (anodic stability: >5 V vs Li/Li + ) and low‐potential (cathodic stability: <0 V vs Li/Li + ) imidazolium ionic liquids in a hexagonal boron nitride nanoplatelet matrix. These layered heterostructure ionogel electrolytes lead to extended electrochemical windows, while preserving high ionic conductivity (>1 mS cm −1 at room temperature). Using the layered heterostructure ionogel electrolytes, full‐cell solid‐state lithium‐ion batteries with a nickel manganese cobalt oxide cathode and a graphite anode are demonstrated, exhibiting voltages that are unachievable with either the high‐potential or low‐potential ionic liquid alone. Compared to ionogel electrolytes based on mixed ionic liquids, the layered heterostructure ionogel electrolytes enable higher stability operation of full‐cell lithium‐ion batteries, resulting in significantly enhanced cycling performance.

Hyun, Woo Jin↗
DOE OSTI2024

Elucidating the Role of Carbon Conductive Additive in the Processing and Electrochemical Behavior of Surface-Modified Si Anodes

In the present work, we explore the impact of conducting carbon on the processing of silicon (Si)-rich electrodes, their resulting cycling performance, and parasitic side reactions. We employed three different carbon additives, Super C45 (carbon black), Super C65 (carbon black), and TIMCAL C-NERGY KS 6L (graphite), with varying sizes and morphologies to determine how these parameters influence the structure and the electrochemical behavior of the cast electrodes. Raman mapping indicates that the improved performance achieved using C45 can be explained by the homogeneous distribution of Si and carbon, enabling the formation of continuous electrical pathways throughout the electrode. Further, this finding aligns with the results of ζ potential measurements, which indicate that C45 can maintain more stable dispersions in N-methyl-2-pyrrolidone (NMP) compared with the other carbon additives. However, electrodes with C45 as the conducting agent exhibited increased parasitic side reactions, as evidenced by the leakage current obtained from voltage hold experiments. These side reactions can have adverse effects on the calendar life of the electrode. Furthermore, the Raman maps of the electrodes reveal heterogeneities in Si and carbon distribution with lower carbon content, especially with only 2% carbon. This drastically impacts the cyclability of the electrodes, with portions of the low-carbon electrodes that remain unable to undergo cycling even at slow rates (0.2 Ah g –1 ). Additionally, we found that slower formation rates are favored in the context of parasitic side reactions, although slower formation rates can potentially create thicker passivating films that could hinder Li + -ion transport. Therefore, we emphasize the need for an intricate balance in materials selection and cycling protocol for optimal electrode processing and electrochemical behavior.

25 ENERGY STORAGE↗
DOE OSTI2013

Dual phase polymer gel electrolyte based on non-woven poly(vinylidenefluoride-co-hexafluoropropylene)–layered clay nanocomposite fibrous membranes for lithium ion batteries

Graphical abstract: Display Omitted Highlights: ► P(VdF-co-HFP)–clay nanocomposite based electrospun membranes are prepared. ► The membranes are used as polymer gel electrolyte (PGE) in lithium ion batteries. ► The composite PGE shows ionic conductivity of 5.5 mS cm{sup −1} at room temperature. ► Li/PGE/LiFePO{sub 4} cell delivers initial discharge capacity of 160 mAh g{sup −1}. ► The use of prepared electrolyte significantly improved the cell performance. -- Abstract: A new approach for fabricating polymer gel electrolytes (PGEs) based on electrospun poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) incorporated with layered nanoclay has been employed to enhance the ionic conductivity and electrochemical properties of P(VdF-co-HFP) without compromising its mechanical strength. The effect of layered nanoclay on properties of membranes has been evaluated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Surface morphology of the membranes has been studied using field-emission scanning electron microscopy (FE-SEM). Polymer gel electrolytes are prepared by soaking the fibrous membrane into 1 M LiPF{sub 6} in EC/DEC. The electrochemical studies show that incorporation of layered nanoclay into the polymer matrix greatly enhanced the ionic conductivity and compatibility with lithium electrodes. The charge–discharge properties and cycling performance of Li/LiFePO{sub 4} cells comprising nanocomposite polymer gel electrolytes have been evaluated at room temperature.

36 MATERIALS SCIENCE↗
DOE OSTI2024

The Microscopic Mechanism of Lithiation and Delithiation in the Ag/C Buffer Layer for Anode‐Free Solid‐State Batteries

Abstract Lithium metal solid‐state batteries (LMSSBs) have demonstrated their high energy density and cycling performance at high current densities in an anode‐free architecture, featuring a thin Ag/C composite buffer layer (BL) between the current collector (CC) and the solid electrolyte (SE). This study explains the microscopic mechanism of the Ag/C BL by using first‐principles atomistic and continuum modeling. It is shown that Ag effectively acts as a homogeneous solid‐solution beyond AgLi 2.32 and maintains a positive potential even at AgLi 25 during lithiation. Key factors underlying the working of the Ag/C BL include lower interfacial resistance at the BL/CC interface than at the BL/SE interface, leading to predominant Li deposition on BL/CC, and substantial Ag–Li volume expansion during lithiation. This, combined with stronger BL/SE adhesion, causes BL/SE separation and Ag–Li extrusion toward the CC side. During delithiation, Ag re‐precipitates as nanoparticles uniformly on the CC, with its positive lithiation potential homogenizing Li currents in subsequent cycles. Other metals are less effective due to their relatively large overpotential, premature lithiation termination, and limited volume expansions hindering movement toward the CC. The study aids the BL design, focusing on metal choice and optimization material and microstructural properties, such as the Li‐ion conductivity and interfacial resistance.

25 ENERGY STORAGE↗
DOE OSTI2015

Low-current field-assisted assembly of copper nanoparticles for current collectors

Current collectors are essential features of batteries and many other electronic devices being responsible for efficient charge transport to active electrode materials. Three-dimensional (3D), high surface area current collectors considerably improve the performance of cathodes and anodes in batteries, but their technological implementation is impeded by the complexity of their preparation, which needs to be simple, fast, and energy efficient. In this paper we demonstrate that field-stimulated assembly of ~3 nm copper nanoparticles (NPs) enables the preparation of porous Cu NP films. The use of NP dispersions enables 30× reduction of the deposition current for making functional 3D coatings. In addition to high surface area, lattice-to-lattice connectivity in the self-assembly of NPs in 3D structures enables fast charge transport. The mesoscale dimensions of out-of-plane features and the spacing between them in Cu films made by field-stimulated self-assembly of NPs provides promising morphology for current collection in lithium ion batteries (LIBs). Half-cell electrochemical models based on self-assembled films show improved specific capacity, total capacity, and cycling performance compared to traditional flat and other 3D current collectors. While integration of active electrode material into the 3D topography of the current collector needs to be improved, this study indicates that self-assembled NP films represent a viable manufacturing approach for 3D electrodes.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Thermal decomposition pathways of bulk electrolytes on vanadium oxide nanocrystals

The thermal stability of electrolytes at an elevated temperature induced by battery charge-discharge cycling is critical for the long cycling performance of a rechargeable battery. For many multivalent systems, such as rechargeable magnesium batteries, which offer great potential for high energy density and utilize earth-abundant resources, electrolyte instability and electrode surface passivation, arising from electrolyte decomposition, remain as major roadblocks. Understanding the electrolyte decomposition pathways at the electrode-electrolyte interface is essential to provide guidance in overcoming this challenge. In this work, in situ 13 C magic angle spinning nuclear magnetic resonance (MAS NMR) and first-principles calculations were used to investigate the thermal decomposition of the electrolyte in a system consisting of MgV 2 O 4 , a novel cathode for magnesium batteries, mixed with a bulk electrolyte consisting of magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI) 2 ) in diglyme (G2). We show that significant electrolyte decomposition is observed in bulk 1.0 M Mg(TFSI) 2 in G2 mixed with nanometer sized MgV 2 O 4 powder at elevated temperatures. This observation is to mimic the possible thermal decomposition that might happen during battery cycling. We demonstrate that the MgV 2 O 4 surface is covered by a layer of decomposed G2 products. We conclude that the dominant reaction pathway for electrolyte decomposition is the thermal decomposition of the pure electrolytes at elevated temperatures, followed by adsorption of G2 decomposition products to the MgV 2 O 4 surface. The activation energy for the major decomposition pathway is obtained. In conclusion, this work highlights the importance of studying thermal decomposition of electrolytes for overall system stability and explores electrolyte stability at significantly elevated temperatures.

25 ENERGY STORAGE↗
DOE OSTI2016

Fuel cycle impacts of accident tolerant fuels

This paper discusses the impact of several accident-tolerant fuel (ATF) options on the fuel cycle performance of once-through LWRs compared to current uranium oxide-Zircaloy fueled commercial LWRs. Desirable characteristics of proposed ATF concepts include higher thermal conductivity, enhanced fission product retention, and reduced reaction kinetics and hydrogen generation in loss of coolant conditions. ATF concepts that have been proposed target changes to the fuel and/or cladding. Broadly speaking, the options can be summarized as follows: -) UO{sub 2} pellet fuels with increased thermal conductivity to lower temperatures, -) high-density pellet fuels (e.g., nitrides and/or silicides), -) fully ceramic microencapsulated (FCM) fuels, -) metallic fuel with high fissile density and high thermal conductivity, -) coatings on Zircaloy cladding, -) total elimination of the Zircaloy as cladding and replacement with a ceramic, and -) composite cladding including for instance layered Zircaloy and SiC and molybdenum. We can draw 4 conclusions. First, other than SiC, the other cladding options will result in a reactivity penalty requiring either thinner cladding or increased fissile loading. Secondly, silicide fuels have a higher density than UO{sub 2} and can allow longer cycle lengths for the same enrichment or a reduction in the enrichment for a given cycle length. Thirdly, while the pellet fuels yield very similar results, the FCM fuel is dramatically different due to the low fuel loading. Fourthly, we have to note that in order to achieve the maximum benefit from a particular fuel-clad combination, it requires consideration of the characteristics of each. For example, a cladding with a relatively high absorption (e.g., FeCrAl) would benefit from a high density fuel such as U{sub 3}Si{sub 2}.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

A stable graphite electrode in superconcentrated LiTFSI-DME/DOL electrolyte and its application in lithium-sulfur full battery

Graphical abstract: In superconcentrated ether-based solutions, the formed SEI film inhibits electrolyte decomposition and graphite exfoliation caused by co-intercalation of solvents. Thus, reversible lithium intercalation and de-intercalation at a graphite electrode has been realized. - Highlights: • Prelithiated graphite anodes are coupled with sulfur composite cathodes to form a Li–S full cell in superconcentrated LiTFSI-DME/DO electrolyte. • The introduced superconcentrated ether-based electrolyte permits reversible lithium intercalation and de-intercalation at a graphite electrode. • The assembled Li–S full battery exhibits better cycle performance and coulombic efficiencies. - Abstract: Herein, prelithiated graphite anodes are coupled with sulfur composite cathodes to form a Li–S full cell in superconcentrated ether electrolyte. This novel system is effective in avoiding sever corrosion of Li-metal anode and significantly improving the safety of present Li–S cell, owing to the replacement of Li-metal anode with graphite. The introduced superconcentrated ether electrolyte has a unique networking structure of Li cations and TFSI anions with Li{sup +}-solvating DME/DOL solvents, which is conducive to form a stable TFSI-derived surface film on the graphite electrode. The stable and dense TFSI-derived film inhibits further electrolyte decomposition and graphite exfoliation caused by co-intercalation of solvents, allowing reversible lithium intercalation and de-intercalation at a graphite electrode. Besides, the severe polysulfides shuttle is also suppressed by the concentrated ether-based solutions. Consequently, the assembled graphite-sulfur full battery retains outstanding capacity of 686 mAh g{sup −1}{sub sulfur} at 0.1C rate after 105 cycles, along with high Coulombic efficiency.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Comprehensive Characterization of Multi-Phase Sulfurized Polyacrylonitrile Cathodes for Lithium-Sulfur Batteries

Sulfurized polyacrylonitrile (SPAN) is considered one of the most promising cathode materials to overcome the operational challenges that plague lithium-sulfur (Li-S) batteries. However, material properties and electrochemical performance implications of SPAN prepared under different synthesis conditions are not yet fully investigated. In this study, we show the impacts of different synthesis conditions on the formation of sulfur to PAN bonds and redox reaction mechanisms of multi-phase SPAN via comprehensive material and electrochemical characterizations. In-situ Raman analysis was first applied to study the multi-phase SPAN-based Li-S cells. We found that both elemental sulfur and chemically bonded sulfur are present under the synthesis condition of 300 degree C/3 h along with unreacted PAN. The incompletely sulfurized, multi-phase SPAN exhibited an unusually rapid capacity degradation in the resultant Li-S cells, which is attributed to polysulfide formation and continuously growing interfacial impedance in the Li-S cells. On the other hand, SPAN samples prepared under the synthesis condition of 350 degree C/3 h are found completely sulfurized with chemically bonded sulfur to the PAN backbone without the presence of free elemental sulfur. Complete sulfurization of SPAN led to exceptionally stable cycle performance due to excellent reversible redox processes of chemically bonded sulfur with Li+ in the Li-S cells.

DIRECT ENERGY CONVERSION,ENERGY STORAGE↗
DOE OSTI2019

Silver-Intermediated Perovskite La 0.9 FeO 3–δ toward High-Performance Cathode Catalysts for Nonaqueous Lithium–Oxygen Batteries

Development of efficient cathode catalysts is crucial for achieving high-performance rechargeable lithium–oxygen batteries. Herein, a simple one-step electrospun method was applied to obtain a silver-modified perovskite La 0.9 FeO 3–δ (Ag@LFO) as an efficient cathode catalyst. The synthesized catalyst has two characteristics: first, the doping of Ag led to a tailored electronic structure including the generation of Fe 4+ ; second, the in situ grown Ag exhibits a stronger interaction with perovskite. These two advantages result in high oxygen adsorbability and increased percentage of highly active oxygen species. Furthermore, film-like Li 2 O 2 was observed during discharge on the Ag@LFO cathode, which is beneficial for decomposition during recharge, whereas Li 2 O 2 generated on the LFO cathode was largely toroidal. Density functional theory calculations were used to discuss the Li 2 O 2 growth mechanism. As a result, compared to La 0.9 FeO 3–δ and post-loading silver-decorated La 0.9 FeO 3–δ (Ag/LFO), Ag@LFO exhibits lower overpotential, improved rate-capability, higher discharge specific capacity, and especially promoted cycling performance that is triple that of LFO.

25 ENERGY STORAGE↗