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At least 199 records · Page 11

Dual Passivation of Cathode and Anode through Electrode–Electrolyte Interface Engineering Enables Long-Lifespan Li Metal–SPAN Batteries

The reliability and durability of lithium metal (Li 0 )–sulfur batteries are largely limited by the undesired Li 0 plating-stripping irreversibility and the detrimental polysulfide dissolution, yet approaches that can simultaneously address the above anodic and cathodic problems are scarce. In this study, we report the stable operation of a Li 0 -SPAN (sulfurized polyacrylonitrile) battery via an anode–cathode dual-passivation approach. By combination of a fluorinated localized high concentration electrolyte (LHCE) and a Li 3 N-forming additive (TMS-N 3 ), robust and highly conductive electrode passivation layers are formed in situ on the surface of both the Li 0 anode and the SPAN cathode. The resulting highly reversible, dendrite-free, and high-density Li 0 plating morphology enables a high Coulombic efficiency of 99.4%. Advanced tender energy X-ray spectroscopy also reveals the eliminated Li 2 S formation and minimized polysulfide dissolution in SPAN cathodes, leading to a high capacity of 580 mAh/g SPAN and stable cycling with negligible capacity decay (0.7%) for 800 cycles. This electrode–electrolyte interphase engineering strategy has tackled the major limitations of Li–S batteries in both ether- and carbonate-based electrolyte systems and under a wide temperature range from –10 to +50 °C, thus providing insightful guidelines for the rational design of highly durable and high-energy-density Li 0 -S batteries.

25 ENERGY STORAGE↗

Computationally Guided Development of Components for High Energy Density Solid-State Lithium-Sulfur Batteries

All electric vertical take-off and landing vehicles (eVTOL) for urban air mobility (UAM) concepts face numerous challenging technical barriers before their introduction into the consumer marketplace. The most challenging of these technical barriers to overcome is developing an energy storage system capable of meeting the rigorous aerospace safety and performance criteria1. The performance metrics for eVTOL craft, such as specific energy, specific power, and safety, exceed those of electric automobiles by a factor of two to four. Current state-of-the-art (SOA) lithium-ion batteries are incapable of meeting the key performance criteria of energy and safety for eVTOL. Therefore, next generation advanced chemistries and designs must be developed to meet required performance metrics for electric aviation2. Beyond lithium-ion chemistries, such as lithium-sulfur, show promise in their high energy, while limitations exist in their power and cyclability due to low electrical conductivity and high intermediate solubility in organic liquid electrolytes. Several strategies to overcome the low electrical conductivity involve the use of selenium as a dopant in the active sulfur material, along with the incorporation of 2-dimensional electron-conducting holey-graphene to improve the composite cathodes electronic conductivity. Furthermore, combining this chemistry with a solid-electrolyte avoids the components’ dissolution issues3. However, the development of composite solid-state cathodes is non-trivial as several components must be intimately mixed so that the active component has sufficient access to both electrons and lithium ions to undergo full electrochemical conversion. Mathematical modeling of battery components can assist experimental design through a robust and rigorous combination of computational modeling techniques covering multiple length scales. The objective is to leverage modern computational materials methods combined with battery multiphysics tools to develop radically advanced compatible cathode and electrolyte materials, build and test solid state lithium-sulfur cells and packs. A NASA-based cross-organizational team of high-powered experts combined integrated computational predictive modeling, fundamental chemistry analysis, advanced material science, and battery cell development to tackle this very challenging, multidisciplinary problem. This presentation will show a multiscale computational modeling approach that has produced a novel particle dynamics method called Solid Electrolyte Sphere Approximation Model (SESAM). SESAM modeling targets the 1-10 µm scale structures and provides electromechanical and grain interactions for predictive design guidelines for the manufacturing of solid-state components. Parameters such as particle size and volume fraction of the constituent materials were modeled and experimentally fabricated to optimize electrochemical performance through improved microstructure design. Experimental feedback was provided through ionic and electronic conductivity assessment and structural analysis of developed materials and cell components.

battery↗

Molten-Salt Electrolysis

Concept of electrolytic decomposition of gaseous hydrogen sulfide to yield gaseous sulfur at anode and hydrogen gas at cathode considered.

Cubicciotti, D.↗

An inverse vulcanized conductive polymer for Li–S battery cathodes

Polymers with a broad range of properties, structural diversity, and mechanical flexibility have been adopted in all aspects of Li–S batteries. However, currently explored polymers for Li–S cathodes suffer from low conductivity, low S content, and poor cycling performance. In this first-principles study, we theoretically design a new polymer, poly(2-vinyl,1,4-phenylene sulfide), by modifying the conductive poly(1,4-phenylene sulfide) via the vinyl group to enhance its ability to vulcanize with element S. Furthermore, we compare the properties of the experimentally realized sulfur vulcanized polymers via condensation and our designed sulfur vulcanized polymers via crosslinking as Li–S battery cathodes, in terms of gravimetric and specific capacities, as well as structural stability during the lithiation. Overall, we find that our designed polymer possesses better conductivity, higher specific capacity and gravimetric energy density, and better kinetic stability, and restricts the shuttle effect more efficiently than the current experimentally explored one. Also, the cross-linked sulfur compounds can be activated efficiently due to the short transport lengths rather than dissolution in the electrolyte during battery operation. Therefore, we believe our designed polymer cathode is promising for practical applications.

25 ENERGY STORAGE↗

A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

NASA's Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair lunar lander and the Extravehicular Activities (EVA) advanced lunar surface spacesuit. These customers require safe, reliable energy storage systems with extremely high specific energy as compared to today's state-of-the-art batteries. Based on customer requirements, the specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery level at 0 degrees Celsius (degrees Celcius) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation over 0 to 30 degrees C, and 200 cycles are targeted. The team, consisting of members from NASA Glenn Research Center, Johnson Space Center, and Jet Propulsion laboratory, surveyed the literature, compiled information on recent materials developments, and consulted with other battery experts in the community to identify advanced battery materials that might be capable of achieving the desired results with further development. A variety of electrode materials were considered, including layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. lithium-sulfur systems were also considered. Hypothetical cell constructs that combined compatible anode and cathode materials with suitable electrolytes, separators, current collectors, headers, and cell enclosures were modeled. While some of these advanced materials are projected to obtain the desired electrical performance, there are risks that also factored into the decision making process. The risks include uncertainties due to issues such as safety of a system containing some of these materials, ease of scaling-up of large batches of raw materials, adaptability of the materials to processing using established or reasonable cost manufacturing techniques, manufacturability of the materials in dimensions required for integration into battery cells of practical capacities, low Technology Readiness levels (TRl), and the ability to achieve the desired performance by the customer need dates. The advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide (lithium NMC) cathode with a silicon-based composite anode was selected as the technology that can offer the best combination of safety, specific energy, energy density, and likelihood of success. Tasks over the next three years will focus on development of electrode materials, compatible electrolytes, and separator materials, and integration of promising components to assess their combined performance in working cells. Cells of the chosen chemistry will be developed to TRl 6 by 2014 and will then be transferred to the customers for infusion into their mission paths.

Reid, Concha↗

Electrochemically Stable High Energy Density Lithium-Sulfur Batteries

Lithium-Sulfur batteries (LSB) have emerged as one of the strong contenders for high energy density rechargeable batteries in the Li-ion battery domain. The LSB system is considered as the most promising to achieve the next milestone in energy density of 500 Wh/kg. However, the LSB system is plagued with problems of polysulfide formation which are soluble in the organic electrolyte leading to loss in capacity and eventual cell failure. The problem is further compounded by dendrite formation on the Li anode during electrochemical cycling leading to puncturing of the separator causing eventual short-circuiting of the cell and consequent heat generation resulting in major safety hazards of flammability of the organic liquid electrolyte and impending explosion. This chapter describes various approaches developed to combat both cathode and anode issues. These involve synthesis and characterization of complex framework materials (CFMs) for confining the polysulfides and sulfur in the LSB cathodes. The CFMs include a CFM host and a coating applied to the CFM host, which includes one or more form of an electronic conductor, a lithium-ion conductor and a functional electrocatalyst for electrocatalytically converting the soluble polysulfides to Li 2 S. Further, sulfur is infiltrated into the CFM host creating a sulfur-carbon linkage serving as effective anchors for trapping the ensuing polysulfides. The systems have been tested in coin cells and pouch cells with metallic Li anodes under lean electrolyte conditions of 3-4 μl/mg of electrolyte (E) to sulfur (S) ratios showing promise and feasibility. New emergent dendrite-free alloys have also been identified to test against pure Li and CFM cathodes in coin cell and pouch cell configurations under lean electrolyte conditions. Results of these studies are described and discussed with thoughts on future directions.

25 ENERGY STORAGE↗

Effect of Antagonistic Binder–Catalyst Interactions on Catalytic Activity in Lithium–Sulfur Batteries

Lithium-sulfur (Li-S) batteries are a promising next-generation energy storage solution, as they can reduce reliance on critical transition metals while offering high energy densities. However, their deployment is hindered by low sulfur utilization and the formation/diffusion of lithium polysulfides (LiPSs). While transition-metal catalysts and polymeric binders have been independently developed to enhance redox kinetics and LiPS adsorption, their mutual compatibility has remained largely unexplored. We show here that binder-catalyst interactions can significantly impact catalytic performance. Employing TiO 2 as a generic catalyst, the electrochemical performance is shown to depend strongly on the binder environment. TiO 2 paired with lithiated polyacrylic acid (LiPAA) shows benign interactions, resulting in enhanced cycle life. In contrast, pairing TiO 2 with protonated PAA produces antagonistic interactions that hinder Li 2 S growth. A mechanistic analysis unveils that the carboxylic H atom in PAA promotes COO − coordination to Ti sites, occupying catalytic centers and suppressing LiPS adsorption, increasing charge transfer and diffusion resistances. This phenomenon is observed across multiple catalysts, indicating that COOH-functionalized binders may broadly hinder catalytic activity. Overall, this study underscores the need for holistic cathode design and identifies binder-catalyst compatibility as an important parameter for high-performance Li-S batteries.

25 ENERGY STORAGE↗

Sulfur Poisoning and Performance Recovery of SOFC Air Electrodes

The sulfur poisoning and performance recovery of the state-of-the-art SOFC cathodes (La 0 . 80 Sr 0 . 20 ) 0 . 95 MnO 3 ± δ (LSM) and (La 0 . 60 Sr 0 . 40 ) 0 . 95 Co 0 . 20 Fe 0 . 80 O 3 – δ (LSCF), have been studied. Electrochemical impedance spectroscopy measurements of LSCF|GDC and LSM|YSZ half-cells are carried out in alternating atmospheres of air and SO 2 –air at 700°C for hundreds of hours. In the presence of SO 2 , the electrochemical performance of both the cells decays with ohmic and non-ohmic losses, owing to the absorption and chemical interaction of SO 2 with the electrodes. In LSCF, the SrO segregated on the surface tends to absorb and react with SO 2 , forming SrSO 4 followed by the exsolution of Co-Fe. As for LSM, SO 2 is absorbed onto the Sr-rich areas of LSM, including the active reaction sites near the TPBs, leading to Sr exsolution and SrSO 4 formation, leaving a Sr-deficient LSM. During the subsequent exposure to air, the performance of the sulfur-contaminated LSM is almost restored. The LSM particles, exposed to alternating atmospheres of air and SO 2 -air during the electrochemical tests, show a relatively clean surface with sparsely distributed SrSO 4 particles, indicating a high stability against sulfur poisoning. It is suggested that the loosely adsorbed SO 2 at the TPBs is readily swept away by the SO 2 -free air flow, recovering its ORR activity, whereas the Sr-deficient LSM due to Sr-exsolution stays modified, contributing to the incomplete performance restoration. Unlike the case of LSM, the performance of the sulfur-poisoned LSCF partially recovers during the subsequent exposure to air. Correspondingly, the LSCF particles have a modified morphology covered with numerous nanoparticles, mostly SrSO 4 , showing the irreversible aspect of the sulfur poisoning. The morphology modification is not concentrated near the electrode/electrolyte interface but over the entire cathode, indicating that the degree of recovery from sulfur poisoning is closely related to the presence of SrO and chemical activity of Sr in the electrodes at the solid-gas interface. These results also show the potential application of LSM for a sulfur sensor available in high-temperature harsh conditions.

25 ENERGY STORAGE↗

Understanding the Roles of the Electrode/Electrolyte Interface for Enabling Stable Li∥Sulfurized Polyacrylonitrile Batteries

Sulfurized polyacrylonitrile (SPAN) is a promising high-capacity cathode material. Here, we use spatially resolved X-ray absorption spectroscopy combined with X-ray fluorescence (XRF) microscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy to examine the structural transformation of SPAN and the critical role of a robust cathode–electrolyte interface (CEI) on the electrode. LiS x species forms during the cycling of SPAN. However, in carbonate-based electrolytes and ether-based electrolytes with LiNO 3 additives, these species are well protected by the CEI and do not dissolve into the electrolytes. In contrast, in an ether-based electrolyte without the LiNO 3 additive, LiS x species dissolve into the electrolyte, resulting in the shuttle effect and capacity loss. Examination of the Li anode by XRF and SEM reveals dense spherical Li morphology in ether-based electrolytes, but sulfur is present in the absence of the LiNO 3 additive. In contrast, porous dendritic Li is found in the carbonate electrolyte. These analyses established that an ether-based electrolyte with LiNO 3 is a superior choice that enables stable cycling of both electrodes. Based on these insights, we successfully demonstrate the stable cycling of high areal loading SPAN cathode (>6.5 mA h cm –2 ) with lean electrolyte amounts, showing promising Li∥SPAN cell performance under practical conditions.

25 ENERGY STORAGE↗

Insight Into Sulfur‐Containing Additive to Boost Anti‐Oxidation Ability of the Ether‐Based Electrolyte for Sodium‐Ion Full Batteries

Ether-based electrolytes are considered as promising candidates for sodium-ion batteries (SIBs) due to their high ionic conductivity and good compatibility with hard carbon (HC) anode. However, they suffer from poor anti-oxidative ability with unstable cathode electrolyte interface, inducing successive electrolyte decomposition and rapid capacity fading. Herein, the sulfur-containing additive (1,3-propanediol cyclic sulfate, PCS) is introduced to boost the stability of the electrode-electrolyte interface (EEI) in ether-based electrolyte. PCS largely participates in the inner Na + sheath, causing more diglyme (G2) molecules and fewer PF 6 - anions to occupy the inner Na + solvation sheath, avoiding the decomposition of G2 molecules at high operation voltage. Moreover, PCS is beneficial for simultaneously constructing thin and robust sulfur-containing EEI on both Prussian blue (PB) cathode and HC anode, maintaining the structural stability of PB and alleviating the dissolution of transition metals. These enable PB||HC pouch cells to deliver a capacity retention of 60.3% after 400 cycles, significantly higher than the 32.1% in PCS-free electrolytes. In conclusion, this work discloses the underlying mechanism of PCS to evoke the anti-oxidation ability of ether-based electrolyte and provides a promising method for realizing advanced sodium-ion full cells.

anti-oxidation ability↗

Phloroglucinol–2,6‐Diaminoanthraquinone as a Durable Redox Mediator for Enhancing Conversion Reaction Kinetics in Lithium‐Sulfur Batteries

Abstract Lithium‐sulfur batteries, despite being a promising solution for next‐generation secondary batteries, require substantial efforts to overcome the challenges of sluggish sulfur redox kinetics, polysulfides shuttling, and Li metal instability before achieving practical viability. Conventional strategies that utilize metal catalysts or soluble redox mediators (RMs) are limited by either impractical producing processes or unsatisfactory service life. Herein, an electrochemically active organic material, phloroglucinol – 2,6‐diaminoanthraquinone (PG‐DAAQ) is synthesized through a green and facile polymerization process to better resolve these issues. Serving as an RM at the cathode, PG‐DAAQ exhibits enduring redox activity within the sulfur operating potential window, leading to enhanced redox kinetics and sulfur utilization. Remarkably, even without any metal elements, PG‐DAAQ exhibits an excellent affinity to polysulfides, thereby suppressing the shuttling and facilitating the formation of a more favorable solid‐electrolyte interface to stabilize Li deposition at the anode. As a result, Li‐S cells employing PG‐DAAQ show significantly enhanced cycling and rate performances than the control cells. Even with a low electrolyte‐to‐sulfur ratio of 6, pouch cells with PG‐DAAQ deliver a reversible discharge capacity of 821 mA h g −1 after 100 cycles at a C/10 rate.

Lai, Tianxing↗

Gas permeable fluoropolymers and ionomers

Novel copolymers that are fluoropolymers including a first repeat unit that is fluorinated and cyclic and a second repeat unit from a trifluorovinyl methylene ether monomer having sulfur or sulfone functionality in the pendant group are disclosed. The copolymers have relatively high gas permeability as a result of a cyclic repeat unit in the copolymer backbone and ionomers from oxidation of the sulfur containing functionality are particularity useful in the cathode structure of a proton exchange membrane fuel cell.

Lousenberg, Robert Daniel↗

An Evaluation of Energy Storage Cost and Performance Characteristics

The energy storage industry continues to expand globally as costs continue to fall and opportunities in consumer, transportation and grid applications are defined. As the rapid evolution of the industry continues, it has become increasingly important to understand how varying technologies compare in terms of cost and performance. This paper defines and evaluates cost and performance parameters of six battery energy storage technologies (BESS) - lithium-ion batteries, lead-acid batteries, redox flow batteries, sodium-sulfur batteries, sodium metal halide batteries, and zinc-hybrid cathode batteries - four non-BESS storage technologies - pumped storage hydropower, flywheels, compressed air energy storage, and ultracapacitors - and combustion turbines. Cost and performance information was compiled based on an extensive literature review, conversations with vendors and stakeholders, and costs of systems procured at sites across the United States. Detailed cost and performance estimates are presented for 2018 and projected out to 2025. Annualized costs were also calculated for each technology.

Mongird, Kendall↗

Design Principles of Single Atoms on Carbons for Lithium–Sulfur Batteries

The study of lithium-sulfur (Li-S) batteries has generated various rationally designed cathodes and modified separators. However, the shuttle of soluble lithium polysulfides (LiPSs) and the sluggish kinetics of transformation of LiPSs to Li2S2/Li2S still hinder the achievement of long-life cycling and high-rate of Li-S batteries. Even though several kinds of nanocatalysts have been studied, the catalytic effects for Li-S batteries are not ideal. Single atoms (SAs) with high surface free energy are found to serve as both anchoring and electrocatalytic centers for LiPSs. Furthermore, atomically dispersed metal catalyst on carbon provide conductive and flexible host for dielectric sulfur. Moreover, SAs as the uniform lithiophilic sites can reduce the nucleation overpotential and ensure uniformly plating of Li. In this review, the latest strategies for preparation of SAs supported on carbons are provided on the application of Li-S batteries, including cathode, modified separator and Li metal anode. In addition, it also discusses how SAs with high catalytic activity can help build better Li-S batteries and the design principles for SAs. Finally, the future directions of SAs in energy storage applications is proposed.

25 ENERGY STORAGE↗

Anion Vacancies Coupling with Heterostructures Enable Advanced Aerogel Cathode for Ultrafast Aqueous Zinc‐Ion Storage

As a potential cathode material, manganese-based sulfide has recently attracted increasing interest due to its many advantages in aqueous zinc-ion storage. Unfortunately, some challenges such as sluggish kinetics, unstable structure, and controversial phase transition mechanism during the energy storage process hinder its practical application. Herein, inspired by density functional theory (DFT) calculations, a novel 3D sulfur vacancy-rich and heterostructured MnS/MXene aerogel is designed, and used as a cathode for aqueous Zn-ion batteries/hybrid capacitors (ZIBs/ZICs) for the first time. Thanks to the synergistic modification strategy of sulfur vacancies and heterostructures, the as-constructed MnS/MXene//Zn ZIBs exhibit significantly enhanced electrochemical properties, especially outstanding rate capability and cyclic stability. More encouragingly, the as-assembled MnS/MXene//porous carbon (PC) ZICs exhibit an ultrahigh energy density, a high power density, and a splendid cycling lifespan. Most notably, systematic kinetic analyses, ex situ characterizations, and DFT calculations illustrate that MnS/MXene first irreversibly converts into MnO x @ZnMnO 3 /MXene, and then undergoes a reversible conversion from MnO x @ZnMnO 3 /MXene to MnOOH@ZnMn 2 O 4 /MXene, accompanied by the co-insertion/extraction of H + and Zn 2+ . Further, the synergistic modification strategy of sulfur vacancies and heterostructures and the thorough mechanistic study proposed in this work offer valuable guidance for designing and exploiting high-performance cathodes in aqueous zinc-based energy storage devices.

25 ENERGY STORAGE↗

Design of Sodium Chalcohalide Solid Electrolytes with Mixed Anions for All‐Solid‐State Sodium‐Ion Batteries

Solid-state sodium-ion batteries (SSNIBs) have emerged as a promising alternative to lithium-ion systems for grid-scale energy storage, owing to sodium's abundance and the improved safety of solid-state designs. Among various solid-state electrolytes (SSEs), halide-based Na + SSEs offer high electrochemical stability but are limited by low ionic conductivity and poor thermal stability. Herein, a novel class of sodium hafnium chalcohalide SSEs is reported with a dual-anion (S 2− /Cl − ) framework, with a high ionic conductivity of 4.5 × 10 −4 S cm −1 . The incorporation of sulfur enhances Na⁺ mobility by reducing the migration barrier through increased anion polarizability and expanded diffusion pathways. Additionally, S 2− contributes to stronger interatomic bonding, leading to higher cohesive energy density, improved thermal stability, and mechanical robustness. These SSEs exhibit minimal sulfur oxidation and excellent chemical/electrochemical interface stability with different cathode materials, such as O3-layered NaNi 1/3 Fe 1/3 Mn 1/3 O 2 , P2/O3 layered Na 0.85 Mn 0.5 Ni 0.4 Fe 0.1 O 2 , and Na 3 V 2 (PO 4 ) 3 cathodes. As a result, SSNIBs with P2/O3 layered Na 0.85 Mn 0.5 Ni 0.4 Fe 0.1 O 2 employing the sodium hafnium chalcohalide SSEs demonstrate outstanding cycling performance, achieving a capacity retention of 88.5% after 200 cycles at 0.1 C. This study establishes a new design strategy for high-performance SSEs, demonstrating that mixed-anion frameworks offer a viable route to overcome the intrinsic limitations of single-anion electrolytes in next-generation SSNIBs.

DFT calculation↗

A high power lithium thionyl chloride battery for space applications

A high power, 28 V, 330 A h, active lithium thionyl chloride battery has been developed for use as main and payload power sources on an expendable launch vehicle. Nine prismatic cells, along with the required electrical components and a built-in heater system, are efficiently packaged resulting in significant weight savings over presently used silver-zinc batteries. The high rate capability is achieved by designing the cells with a large electrochemical surface area and impregnating an electrocatalyst, polymeric phthalocyanine, into the carbon cathodes. Passivation effects are reduced with the addition of sulfur dioxide into the thionyl chloride electrolyte solution. The results of conducting a detailed thermal analysis are utilized to establish the heater design parameters and the thermal insulation requirements of the battery. An analysis of cell internal pressure and vent characteristics clearly illustrates the margins of safety under different operating conditions. Performance of fresh cells is discussed using polarization scan and discharge data at different rates and temperatures. Self-discharge rate is estimated based upon test results on cells after storage. Results of testing a complete prototype battery are described.

Shah, Pinakin M.↗