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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
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↗
NASA NTRSDate not supplied

Ultrahigh Areal Capacity Holey Graphene Air Cathodes for Li-O2 and Li-CO2 Batteries

Advanced lithium (Li) batteries using gaseous cathode reactants such as oxygen (O2) and carbon dioxide (CO2)are attractive energy storage platforms because the gases are obtained externally and thus not accounted for in the total battery weight when fully charged.The discharge products at the cathode, typically Li2O2 for Li-O2 batteries and Li2CO3 for Li-CO2 batteries, are insoluble in the electrolyte.Therefore, in order for such batteries to function properly, an “air cathode”,which is a conductive scaffold within the battery cell,is required as a physical location for cathode electrochemical reactions to occur. Prior research has identified many carbon nanomaterials such as carbon nanotubes and graphene as viable choices for air cathode scaffold, while various metallic and metal-free catalytic systems integrated onto carbon-based air cathodes have been developed to improve the sluggish discharge and charge reactions. For future practical applications, the air cathode must exhibit a usable capacity per unit electrode area, or areal capacity, a critical parameter that has been largely overlooked so far in this field. In order to achieve high areal capacity, the air cathode must exhibit a sufficient amount of accessible void volume per unit electrode area while maintaining the conductive scaffold integrity during the entire electrochemical process. Here we present an ultrathick,holey graphene-based air cathode platform fabricated from a facile dry compression process that exhibits remarkable areal capacity values. Holey graphene is a carbon nanomaterial derived from graphene, but with nanometer sized holes through the nanosheet thickness.The presence of these holes enhances mass transport through electrode thickness and also enables the unique dry-press fabrication process that is not achievable using other carbon scaffold materials.The dry-pressed holey graphene air cathode platform is not only compatible with catalyst incorporation to improve battery reaction kinetics, but also allows for novel engineering of electrode architectures that is not achievable using conventional electrode fabrication approaches.The applications of such highly versatile, ultrahigh areal capacity air cathode platforms to both Li-O2 and Li-CO2 battery chemistries will be discussed.

Li-O2 batteries, Li-CO2 batteries, holey graphene,↗
DOE OSTI2023

Fluoride-Rich, Organic–Inorganic Gradient Interphase Enabled by Sacrificial Solvation Shells for Reversible Zinc Metal Batteries

Zinc metal batteries are strongly hindered by water corrosion, as solvated zinc ions would bring the active water molecules to the electrode/electrolyte interface constantly. Herein, we report a sacrificial solvation shell to repel active water molecules from the electrode/electrolyte interface and assist in forming a fluoride-rich, organic-inorganic gradient solid electrolyte interface (SEI) layer. Additionally, the simultaneous sacrificial process of methanol and Zn(CF 3 SO 3 ) 2 results in the gradient SEI layer with an organic-rich surface (CH 2 OC- and C 5 product) and an inorganic-rich (ZnF 2 ) bottom, which combines the merits of fast ion diffusion and high flexibility. As a result, the methanol additive enables corrosion-free zinc stripping/plating on copper foils for 300 cycles with an average coulombic efficiency of 99.5%, a record high cumulative plating capacity of 10 A h/cm 2 at 40 mA/cm 2 in Zn/Zn symmetrical batteries. More importantly, at an ultralow N/P ratio of 2, the practical VO 2 //20 mu m thick Zn plate full batteries with a high areal capacity of 4.7 mAh/cm 2 stably operate for over 250 cycles, establishing their promising application for grid-scale energy storage devices. Furthermore, directly utilizing the 20 μm thick Zn for the commercial-level areal capacity (4.7 mAh/cm 2 ) full zinc battery in our work would simplify the manufacturing process and boost the development of the commercial zinc battery for stationary storage.

25 ENERGY STORAGE↗
DOE OSTI2024

Superionic conducting vacancy-rich β-Li 3 N electrolyte for stable cycling of all-solid-state lithium metal batteries

The advancement of all-solid-state lithium metal batteries requires breakthroughs in solid-state electrolytes (SSEs) for the suppression of lithium dendrite growth at high current densities and high capacities (>3 mAh cm -2 ) and innovation of SSEs in terms of crystal structure, ionic conductivity and rigidness. Here we report a superionic conducting, highly lithium-compatible and air-stable vacancy-rich β-Li 3 N SSE. This vacancy-rich β-Li 3 N SSE shows a high ionic conductivity of 2.14 × 10 -3 S cm -1 at 25 °C and surpasses almost all the reported nitride-based SSEs. A Li- and N-vacancy-mediated fast lithium-ion migration mechanism is unravelled regarding vacancy-triggered reduced activation energy and increased mobile lithium-ion population. All-solid-state lithium symmetric cells using vacancy-rich β-Li 3 N achieve breakthroughs in high critical current densities up to 45 mA cm -2 and high capacities up to 7.5 mAh cm -2 , and ultra-stable lithium stripping and plating processes over 2,000 cycles. The high lithium compatibility mechanism of vacancy-rich β-Li 3 N is unveiled as intrinsic stability to lithium metal. In addition, β-Li 3 N possesses excellent air stability through the formation of protection surfaces. All-solid-state lithium metal batteries using the vacancy-rich β-Li 3 N as SSE interlayers and lithium cobalt oxide (LCO) and Ni-rich LiNi 0.83 Co 0.11 Mn 0.06 O 2 (NCM83) cathodes exhibit excellent battery performance. Extremely stable cycling performance is demonstrated with high capacity retentions of 82.05% with 95.2 mAh g -1 over 5,000 cycles at 1.0 C for LCO and 92.5% with 153.6 mAh g -1 over 3,500 cycles at 1.0 C for NCM83. Utilizing the vacancy-rich β-Li 3 N SSE and NCM83 cathodes, the all-solid-state lithium metal batteries successfully accomplished mild rapid charge and discharge rates up to 5.0 C, retaining 60.47% of the capacity. Notably, these batteries exhibited a high areal capacity, registering approximately 5.0 mAh cm -2 for the compact pellet-type cells and around 2.2 mAh cm -2 for the all-solid-state lithium metal pouch cells.

25 ENERGY STORAGE↗
DOE OSTI2023

Polysulfide regulation by defect-modulated Ta 3 N 5- x electrocatalyst toward superior room-temperature sodium-sulfur batteries

Resolving low sulfur reaction activity and severe polysulfide dissolution remains challenging in metal-sulfur batteries. Motivated by a theoretical prediction, herein, we strategically propose nitrogen-vacancy tantalum nitride (Ta 3 N 5-x ) impregnated inside the interconnected nanopores of nitrogen-decorated carbon matrix as a new electrocatalyst for regulating sulfur redox reactions in room-temperature sodium-sulfur batteries. Through a pore-constriction mechanism, the nitrogen vacancies are controllably constructed during the nucleation of Ta 3 N 5-x . Further, the defect manipulation on the local environment enables well-regulated Ta 5d-orbital energy level, not only modulating band structure toward enhanced intrinsic conductivity of Ta-based materials, but also promoting polysulfide stabilization and achieving bifunctional catalytic capability toward completely reversible polysulfide conversion. Moreover, the interconnected continuous Ta 3 N 5-x -in-pore structure facilitates electron and sodium-ion transport and accommodates volume expansion of sulfur species while suppressing their shuttle behavior. Due to these attributes, the as-developed Ta 3 N 5-x -based electrode achieves superior rate capability of 730 mAh g -1 at 3.35 A g -1 , long-term cycling stability over 2000 cycles, and high areal capacity over 6 mAh cm -2 under high sulfur loading of 6.2mgcm -2 . This work not only presents a new sulfur electrocatalyst candidate for metal-sulfur batteries, but also sheds light on the controllable material design of defect structure in hopes of inspiring new ideas and directions for future research.

25 ENERGY STORAGE↗
DOE OSTI2024

A dynamically bare metal interface enables reversible magnesium electrodeposition at 50 mAh cm −2

Understanding and facilitating pure magnesium nucleation/growth electrodeposition behavior with ultrahigh Coulombic efficiency is complicated by the phenomenon of solid electrolyte interphase (SEI) formation in state-of-the-art, halogen-free magnesium electrolytes. Defining the electrolyte properties necessary to achieve ideal electrodeposition/stripping (E/S) thus remains elusive. Here, in this work, we reveal for the first time, rapid magnesium electrodeposition behavior that forms densely aligned, micron-sized thin platelets by establishing a dynamic bare magnesium/electrolyte interface during high-rate net plating. This effectively “SEI-free” interface allows facile magnesium diffusion and migration in stripping with near-unity E/S efficiency under demanding conditions over long-term cycling. The intrinsic electrolyte stability of the salt/solvent at the molecular level is the key to forming such an interface. The efficacy of the dynamic bare interface and an electrodeposited, free-standing magnesium anode is demonstrated in a high-areal-capacity full cell. These findings provide new design principles and fundamental understanding of interfacial chemistry in multivalent metal batteries.

Mg full cell↗
DOE OSTI2022

Practically Accessible All-Solid-State Batteries Enabled by Organosulfide Cathodes and Sulfide Electrolytes

The combination of organic electrode materials and sulfide electrolytes is expected to enable the development of all-solid-state organic batteries featuring high energy density and long-term sustainability. In this work, thiuram hexasulfide is reported as a low-cost and high-capacity organic cathode for solid-state batteries based on sulfide electrolytes, delivering a capacity of ~600 mAh g -1 and retaining 80.8 % capacity after 500 cycles. An electrochemically reversible change of the cathode interface was revealed upon cycling. Full cell displays an oscillating stress change up to 0.6 MPa during cycling, predominated by the anode side. The energy density is 1140 Wh kg -1 at the material level and 376 Wh kg -1 at the electrode level, which are among the best-reported organic cathodes to date. A high areal capacity of 10.4 mAh cm -2 is reached with a high mass loading cathode. A dry-film approach is further explored to manufacture sheet-type cells. Free-standing electrolyte film is merely ~48 μm thick and demonstrates an ultralow areal resistance of 3.9 Ω cm 2 , significantly boosts the cell-level energy density and reduces the cell internal resistance.

25 ENERGY STORAGE↗
DOE OSTI2023

Electrochemically Dealloyed 3D Porous Copper Nanostructure as Anode Current Collector of Li-Metal Batteries

The commercialization of high-energy Li-metal batteries is impeded by Li dendrites formed during electrochemical cycling and the safety hazards it causes. Here, a novel porous copper current collector that can effectively mitigate the dendritic growth of Li is reported. This porous Cu foil is fabricated via a simple two-step electrochemical process, where Cu-Zn alloy is electrodeposited on commercial copper foil and then Zn is electrochemically dissolved to form a 3D porous structure of Cu. The 3D porous Cu layers on average have a thickness of ≈14 um and porosity of ≈72%. This current collector can effectively suppress Li dendrites in cells cycled with a high areal capacity of 10 mAh cm -2 and under a high current density of 10 mA cm -2 . This electrochemical fabrication method is facile and scalable for mass production. In conclusion, results of advanced in situ synchrotron X-ray diffraction reveal the phase evolution of the electrochemical deposition and dealloying processes.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Integrated reactor architecture of conductive network and catalytic nodes to accelerate polysulfide conversion for durable and high-loading Li-S batteries

The development of carbon-based heterogeneous framework host with synergistic catalytic and conductive effects for sulfur cathode is a promising strategy to realize high performance lithium sulfur batteries (LSBs). Here, an integrated reactor architecture with defective carbon nodes (IRA-DC) is designed for serving as high-loading (92.4 wt%) sulfur host. The hierarchical porous IRA-DC consists of untangled conductive carbon nanotube network and Co/N co-doped catalytic nodes with high dispersity. Therein the optimization of electric field distribution and homogenization of adsorption-catalysis sites offer the multi-electron conversion reaction of polysulfides with excellent kinetics and stability. The resultant IRA-DC/S cathode enables a high areal capacity of 8.86 mAh cm -2 under ultra-high sulfur loading (13.1 mg cm -2 ) and lean electrolyte (8 μL mg sulfur -1 ). It also displays a long-term cycling performance (1200 cycles at 1 C) and ultrahigh rate performance up to 20 C (with a capacity of 473.6 mAh g -1 ). In conclusion, this work provides an electrode building strategy by optimizing the environments of heterogeneous electrocatalysis and micro electric field to activate the polysulfide conversion efficiency and utilization of high-loading sulfur in monolithic sulfur-carbon cathodes.

25 ENERGY STORAGE↗
DOE OSTI2022

Reviving the rock-salt phases in Ni-rich layered cathodes by mechano-electrochemistry in all-solid-state batteries

The rock-salt phase (RSP) formed on the surface of Ni-rich layered cathodes in liquid-electrolyte lithium-ion batteries is conceived to be electrochemically "dead". Here we show massive RSP forms in the interior of LiNi x Mn y Co (1–x-y) O 2 (NMC) crystals in sulfide based all solid state batteries (ASSBs), but the RSP remains electrochemically active even after long cycles. The RSP and the layered structure constitute a two-phase mixture, a material architecture that is distinctly different from the RSP in liquid electrolytes. The tensioned layered phase affords an effective percolation channel into which lithium is squeezed out of the RSPs by compressive stress, rendering the RSPs electrochemically active. Consequently, the ASSBs with predominant RSP in the NMC cathode deliver remarkable long cycle life of 4000 cycles at high areal capacity of 4.3 mAh/cm 2 . Our study unveils distinct mechano-electrochemistry of RSPs in ASSBs that can be harnessed to enable high energy density and durable ASSBs.

25 ENERGY STORAGE↗
DOE OSTI2021

Rechargeable Alkaline Zinc/Copper Oxide Batteries

Resurrecting a battery chemistry thought to be only primary, we demonstrate the first example of a rechargeable alkaline zinc/copper oxide battery. With the incorporation of a Bi 2 O 3 additive to stabilize the copper oxide-based conversion cathode, Zn/(CuO–Bi 2 O 3 ) cells are capable of cycling over 100 times at >124 W h/L, with capacities from 674 mA h/g (cycle 1) to 362 mA h/g (cycle 150). The crucial role of Bi 2 O 3 in facilitating the electrochemical reversibility of Cu 2 O, Cu(OH) 2 , and Cu o was supported by scanning and transmission electrochemical microscopy, cyclic voltammetry, and rotating ring-disc electrode voltammetry and monitored via operando energy-dispersive X-ray diffraction measurements. Bismuth was identified as serving two roles, decreasing the cell resistance and promoting Cu(I) and Cu(II) reduction. Additionally, to mitigate the capacity losses of long-term cycling CuO cells, we demonstrate two limited depth of discharge (DOD) strategies. First, a 30% DOD (202 mA h/g) retains 99.9% capacity over 250 cycles. Second, the modification of the CuO cathode by the inclusion of additional Cu metal enables performance at very high areal capacities of ~40 mA h/cm 2 and unprecedented energy densities of ~260 W h/L, with near 100% Coulombic efficiency. This work revitalizes a historically primary battery chemistry and opens opportunity to future works in developing copper-based conversion cathode chemistries for the realization of low-cost, safe, and energy-dense secondary batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

A Coordinated-Anion-Enriched Electrolyte for Lean-Electrolyte Li–S Batteries

The solid electrolyte interphase (SEI) on Li and cathode electrolyte interphase (CEI) at sulfurized polyacrylonitrile (SPAN) formed in the commonly used liquid electrolytes cannot accommodate the large volume change of both Li anode and SPAN cathode, resulting in severe electrolyte and Li consumption and fast capacity decay under high mass loading and lean electrolyte condition. Herein, a LiF-rich SEI and a LiF-Li x N y O z co-enriched CEI are simultaneously formed by adding ionic liquid (Py 13 TFSI) in the localized high-concentration electrolyte (LHCE), which forms a coordinated-anion-enriched solvation structure. In this study, the LiF-rich interphase results in less stress/strain during large volume changes of Li and SPAN and therefore achieving obviously improved stability even at a high areal capacity. Consequently, Li (50 μm)||SPAN (6 mg cm -2 ) pouch cells under the lean electrolyte condition (E/S ratio of 5 mL g SPAN -1 ) delivers a stable cycle life of 120 cycles with 79.2% capacity retention, demonstrating great promise for high-energy-density lithium-sulfur batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Tailoring-Orientated Deposition of Li 2 S for Extreme Fast-Charging Lithium–Sulfur Batteries

Precipitation/dissolution of insulating Li 2 S has long been recognized as the rate-determining step in lithium-sulfur (Li-S) batteries, which dramatically undermines sulfur utilization at elevated charging rates. Herein, we present an orientated Li 2 S deposition strategy to achieve extreme fast charging (XFC, ≤15 min) through synergistic control of porosity, electronic conductivity, and anchoring sites of electrode substrate. Via magnesiothermic reduction of a zeolitic imidazolate framework, a nitrogen-doped and hierarchical porous carbon with highly graphitic phase was developed. This design effectively reduces interfacial resistance and ensures efficient sequestration of polysulfides during deposition, leading to (110)-preferred growth of Li 2 S nanocrystalline between (002)-dominated graphitic layers. Our approach directs an alternative Li 2 S deposition pathway to the commonly reported lateral growth and 3D thickening growth mode, ameliorating the electrode passivation. Therefore, a Li-S cell capable of charging/discharging at 5C (12 min) while maintaining excellent cycling stability (82% capacity retention) for 1000 cycles is demonstrated. In conclusion, even under high S loading (8.3 mg cm -2 ) and low electrolyte/sulfur ratio (3.8 mL mg -1 ), the sulfur cathode still delivers a high areal capacity of >7 mAh cm -2 for 80 cycles.

25 ENERGY STORAGE↗
DOE OSTI2021

Large-Area Lithium Electrode Sub-Assemblies (LESAs) Protected by Self Forming Microstructured Polymer-Inorganic Single-Ion Conducting Composites (Final Report)

The aim of this project is to realize a low-cost, safe, reversible, high-areal capacity lithium metal electrode though the use of scalable, low-cost Lithium Electrode Sub-Assembly (LESA). At its core, the LESA applies novel polymer scaffolds to nanostructure inorganic ionic materials into high-conductivity composites that stabilize lithium anodes during high-rate, high-capacity cycling in lithium metal batteries. Fundamental investigations from this project identified a newly defined region of stability for composites with respect to the shear modulus and lithium molar volume ratio which have been broadly applied in the scientific literature for a multitude of different systems. The advancements achieved in this field have furthered the fundamental understanding of lithium metal electrode chemistry and degradation mechanisms and resulted in a lithium metal anode with improved cycle life.

25 ENERGY STORAGE↗
DOE OSTI2021

Efficient diffusion of superdense lithium via atomic channels for dendrite-free lithium–metal batteries

The non-uniform aggregation of fast-diffused Li on an anode surface would aggravate its tip-effect-induced nucleation/growth, leading to the notorious dendrite growth in Li metal batteries (LMBs). Tuning the Li diffusion on the anode surface has been regarded previously as a mainstream method to induce its uniform deposition, while the diffusion of Li in the anode bulk is usually ignored. In this study, conceptually different from the classic surface modification, we propose a molecular tunnelling strategy to construct atomic channels in graphite bulk, which enables the fast diffusion of superdense Li. Density functional theory calculations and ab initio molecular dynamics simulations prove that the bulk diffusion through atomic channels could become a new and dominating path. Its reversible and efficient diffusion has been further visualized by in situ transmission electron microscopy. As a result, when coupled with high-loading LiFePO 4 cathodes (20 mg cm –2 ), a high areal capacity and 100% capacity retention are achieved over 370 cycles. Through this work a new strategy is developed based on the bulk-diffusion of superdense Li for dendrite-free LMBs, which can be pervasive in other high-performance energy storage systems.

25 ENERGY STORAGE↗
DOE OSTI2020

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

Abstract 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. Herein, 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 μL mg −1 ). This research further demonstrates a durable Li‐Se/S pouch cell with high specific capacity, validating the potential practical applications.

Zhao, Chen↗