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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Complementary Effects of Mg and Cu Incorporation in Stabilizing the Cobalt-Free LiNiO 2 Cathode for Lithium-Ion Batteries

Since the discovery of LiNiO 2 several decades ago, a new era of electric vehicles demanding high-energy-density lithium-ion batteries (LIBs) has recently rebooted the interest in this cathode material to eliminate the dependence on expensive and scarcely available cobalt. However, LiNiO 2 has been plagued by cycle instability, thermal instability, and air instability. We present here an exploration of the mutual interaction of magnesium and copper in stabilizing the cobalt-free LiNiO 2 cathode. Although Mg doping is beneficial for the robustness of the bulk structure of LiNiO 2 , surface characterization results of Mg-doped LiNiO 2 implies the need for further surface protection. To that end, we have incorporated Cu in addition to Mg in that Cu stabilizes the surface of Mg-doped LiNiO 2 by forming a protective stable surface layer without harming the bulk. Notable variations of the surface residual lithium composition (Li Li 2 CO 3 /Li LiOH ) along with the incorporation of stabilizers are also discussed. The harmony between Mg and Cu with as little as 0.5 atom % Mg and 0.3 atom % Cu significantly enhances the specific energy and cycle life of LiNiO 2 . Furthermore, this study demonstrates how the co-incorporation of optimal dopants can help stabilize both the bulk and surface and provides new insights toward developing cobalt-free layered oxide cathodes for high-energy-density LIBs.

25 ENERGY STORAGE↗
DOE OSTI2022

A Nearly Zero-Strain Li-Rich Rock-Salt Oxide with Multielectron Redox Reactions as a Cathode for Li-Ion Batteries

Li-rich oxide cathodes are drawing increasing attention as next-generation cathode materials for the development of high-energy-density Li-ion batteries due to their strikingly high capacities. However, transition-metal migration, irreversible structural phase transformations, and the irreversible release of oxygen are responsible for rapid capacity and voltage decay. This study reports a Li-rich cation-ordered rock-salt oxide Li x V 0.4 Ti 0.4 O 2 (LVTO, x = 0.97/1.2) with space group Fd$\bar{3}$m that delivers a high capacity of over 250 mAh g -1 and capacity retention up to 89% after 50 cycles. A comprehensive experimental analysis confirms that the capacity can be attributed to the reversible V 3+ /V 5+ multielectron cationic redox reactions and a minor contribution from reversible anionic redox reactions. Importantly, LVTO exhibits nearly zero-strain behavior upon (dis)charge cycling cycles, which is associated with reversible V migration from octahedral to tetrahedral sites. Here our results demonstrate that Li-rich rock-salt oxide LVTO could be a promising cobalt-free cathode material for Li-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2023

Thermal Stability and Outgassing Behaviors of High‐nickel Cathodes in Lithium‐ion Batteries

Abstract LiNiO 2 ‐based high‐nickel layered oxide cathodes are regarded as promising cathode materials for high‐energy‐density automotive lithium batteries. Most of the attention thus far has been paid towards addressing their surface and structural instability issues brought by the increase of Ni content (>90 %) with an aim to enhance the cycle stability. However, the poor safety performance remains an intractable problem for their commercialization in the market, yet it has not received appropriate attention. In this review, we focus on the gas generation and thermal degradation behaviors of high‐Ni cathodes, which are critical factors in determining their overall safety performance. A comprehensive overview of the mechanisms of outgassing and thermal runaway reactions is presented and analyzed from a chemistry perspective. Finally, we discuss the challenges and the insights into developing robust, safe high‐Ni cathodes.

Cui, Zehao↗
DOE OSTI2024

Factors Influencing Gas Evolution from High‐Nickel Layered Oxide Cathodes in Lithium‐Based Batteries

Abstract Gas evolution from high‐nickel layered oxide cathodes (>90% Ni) remains a major issue for their practical application. Gaseous species, such as CO 2 , O 2 , and CO, that are evolved at high states of charge (SOC) worsen the overall safety of batteries, as pressure build‐up within the cell may lead to cell rupture. Since these gasses are produced during cathode degradation, tracking the formation of gasses is also important in diagnosing cathode failure. Online electrochemical mass spectrometry (OEMS) is a powerful in situ technique to study gas evolution from the cathode during high‐voltage charge. However, the differences in the OEMS experimental setups between different groups make it challenging to compare results between groups. In this perspective, the various factors that influence gas evolution based on the OEMS results collected in this group are presented. The focus is on the conditions that lead to gas release, with a particular emphasis on reactive oxygen formation and subsequent chemical reactions with the electrolyte. Promising strategies, such as electrolytes, compositional tuning, and surface coatings that are effective at suppressing gas evolution from the cathode are highlighted. Critical insights into mitigating cathode degradation and gas evolution are provided to guide the development of safer, high‐energy batteries.

Chemistry↗
DOE OSTI2021

Direct Cathode Recycling of End-Of-Life Li-Ion Batteries Enabled by Redox Mediation

The ongoing surge of electric vehicle (EV) adoption forecasts an unprecedented amount of lithium-ion battery wastes in the near future. Since cathode materials have the highest economic and engineering values, it is essential to recycle and reuse the end-of-life (EOL) cathode materials. Here, we show that redox mediators can deliver lithium ions and electrons from a lithium source to the cathode, efficiently relithiate the EOL cathode materials, and make them ready for new battery production after a postheat treatment. We have found that some quinone-based redox mediators, especially 3,5-di-tert-butyl-o-benzoquinone (DTBQ), can shuttle the charges very fast between Li metal and EOL cathode. Reduction of DTBQ on lithium is evidenced by chemical changes of Li metal and DTBQ, and successful relithiation of the EOL cathode by the subsequent oxidation of DTBQ is verified by electrochemical and structural evaluations.

battery recycling↗
DOE OSTI2023

Elevating the Practical Application of Sodium-Ion Batteries through Advanced Characterization Studies on Cathodes

Sodium-ion batteries (SIBs) have emerged as promising alternatives to their lithium-ion counterparts due to the abundance of sodium resources and their potential for cost-effective energy storage solutions. The chemistry for SIBs has been investigated since the 1980s, but it went through a slow research and development process. Recently, there has been an acceleration in technology maturation due to a supply chain crisis originating from unequal resource distribution and sustainability and safety concerns regarding lithium-ion batteries. However, the practical application of SIBs has been hindered primarily by challenges related to cathode materials, specifically, surface and structural stabilities in different conditions. Through the integration of advanced techniques such as in situ spectroscopy, operando diffraction, and high-resolution microscopy, a comprehensive understanding of the cathode’s dynamic behavior and degradation mechanisms can be achieved. The identified structural modifications, phase transitions, and degradation pathways offer critical insights into the design of robust cathode materials with prolonged cycling stability, fast charging capability, high energy density, great low-temperature performance, and safety. This review underscores the pivotal role of cutting-edge characterization techniques in guiding the development of high-performance sodium-ion batteries, thereby fostering the realization of sustainable and efficient energy storage solutions for diverse technological applications.

25 ENERGY STORAGE↗
DOE OSTI2025

Developing low-cost rechargeable batteries: beyond traditional layered oxide cathodes for Li-ion and beyond Li-ion batteries

Here, the rising demand for energy storage systems, driven by the rapid adoption of electric vehicles and the global shift toward renewable energy, necessitates continuous efforts to lower the cost of current lithium-ion batteries (LIBs) and enhance the sustainability of existing battery chemistries. This feature article examines the key challenges associated with Ni- and Co-containing LIB cathodes and compares advancements in cathode development for non-traditional Li-ion and beyond Li-ion chemistries. First, a review of earth-abundant element containing disordered rock-salt cathodes is presented, with a discussion of key strategies such as compositional tuning and carbon coating to improve their electrochemical performance. Hurdles in developing oxide-based cathodes for Na- and K-ion batteries are also highlighted, followed by an in-depth overview of polyanion and Prussian blue cathodes for Na- and K-ion systems. Overall, this article provides a systematic perspective on the design of earth-abundant, low-cost, and sustainable cathode materials for both LIB and beyond LIB technologies.

Lohani, Harshita [Lawrence Berkeley National Labor↗
DOE OSTI2020

Vanadyl Phosphates A x VOPO 4 (A = Li, Na, K) as Multielectron Cathodes for Alkali-Ion Batteries

Vanadyl phosphates comprise a class of multielectron cathode materials capable of cycling two Li + , about 1.66 Na + , and some K + ions per redox center. In this review, structures, thermodynamic stabilities, and ion diffusion kinetics of various A x VOPO 4 (A = Li, Na, K, NH 4 ) polymorphs are discussed. Both the experimental data and first-principle calculations indicate kinetic limitations for alkali metal ions cycling, especially between for 0 ≤ x ≤ 1, and metastability of phases with x > 1. This creates challenges for multiple-ion cycling, as the slow kinetics call for nanosized particles, which being metastable and reactive with organic electrolytes are prone to side reactions. Thus, various synthesis approaches, surface coating, and transition metal ion substitution strategies are discussed here as possible ways to stabilize A x VOPO 4 structures and improve alkali metal ion diffusion. Finally, the role of advanced characterization techniques, such as X-ray absorption spectroscopy, diffraction, pair distribution function analysis and 7 Li and 31 P NMR, in understanding the reaction mechanism from both structural and electronic points of view is emphasized.

25 ENERGY STORAGE↗
DOE OSTI2024

Unleashing the Potential of Fast Charging Batteries: Leveraging Anion Redox Chemistry in Ni- and Co-Free Cathodes

Designing Li-ion battery cathodes free from critical raw materials such as Co and Ni has a huge technological and societal impact. Though anion redox-based Li-rich oxide cathodes allow designing Co and Ni free cathode compositions, the Li-rich oxides witnessed voltage fade, voltage hysteresis, and irreversible oxygen release despite their high capacity. Conversely, anion redox through highly covalent chalcogenides (S/Se) is emerging due to the improved covalency between metal d and ligand p bands. Here, we investigate the tuning of multi-chalcogen (S/Se) p-band and redox-active metal d-band in a model Li-rich chalcogen composition Li 1.13 Ti 0.57 Fe 0.3 S 2-y Se y (y = 0 - 1) through in-depth electrochemical, X-ray spectroscopy, and DFT-based electronic structure investigations. Introducing the appropriate amount of Se p band character in anion redox sulfides increases interlayer distance and metal - ligand covalency without modifying the original crystal structure, promoting significant electrochemical reversibility through mixed anionic (Se 2- /Se n- , S 2- /S n- , wherein n<2) and cationic (Fe 2+ /Fe 3+ ) redox reactions. Here we show the detailed Fe, S, and Se redox contributions during Li insertion/extraction through X-ray Absorption (XAS) and Hard X-ray Photoemission Spectroscopy (HAXPES) measurements. The orbital tuning approach improves rate capability for more than 10 C charge-discharge rate, exhibiting more than 50% of its original capacity obtained at C/20 rate. The buffer cation in the lattice (Ti 4+ ) remains electrochemically inactive even after significant Se p-band introduction in the sulfide framework. Overall, this work takes advantage of multi-anion redox chemistry to uncover practically demanding fast charging-discharging characteristics in intercalation cathodes. The obtained knowledge of this design can be extended to other oxide and chalcogen cathodes for high performance Li-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2023

Cracking vs. surface reactivity in high-nickel cathodes for lithium-ion batteries

High-nickel layered oxide cathodes LiNi x Mn y Co z O 2 (NMC) experience microcracks during cycling. This can expose fresh cathode surfaces for parasitic reactions and isolate active cathode material from the conductive electrode matrix, resulting in impedance increase and capacity fade. The commonly held belief attributes microcracks to anisotropic lattice volume changes of primary particles during cycling. Nevertheless, recent reports suggest that certain electrolytes might reduce microcracks in NMC cathodes during deep cycling. This raises a crucial question on the origin of microcracks: do microcracks exacerbate surface stability, or does poor surface stability contribute to microcrack formation? This perspective aims to provide context and expound this “chicken or egg” dilemma. We contend that the consequence of surface reactivity on the cycle life of high-Ni cathodes is more pronounced than that of particle cracking. Here, we hypothesize that particle cracking is more of a symptom of severe surface reactivity rather than a cause of capacity fade.

25 ENERGY STORAGE↗
DOE OSTI2020

Dual Functional Ni3S2@Ni Core-Shell Nanoparticles Decorating Nanoporous Carbon as Cathode Scaffolds for Lithium-Sulfur Battery with Lean Electrolytes

Lithium-sulfur batteries are very promising for next-generation energy storage. However, most studies use flooded electrolytes to achieve a high specific capacity at the expense of lowering the specific energy. Understanding lithium-sulfur battery performance with lean electrolytes is highly desirable. Herein, a modified Pechini method is developed to synthesize a nanoporous carbon host decorated with Ni3S2@Ni particles. Such a cathode delivers enhanced specific capacities with extended cycling life in lean electrolytes, due to the dual functions of the Ni3S2 shell, which can both facilitate reaction kinetics and promote electrolyte wetting. This work highlights a strategy to rationally design cathodes for highenergy lithium-sulfur batteries.

Zhang, Yulun↗
DOE OSTI2026

Unraveling the Synergistic effects of La and Al co-doping on Ni/Co-free P2-type Na 0.67 Mn 0.67 Fe 0.33 O 2 layered oxide cathodes for sodium-ion batteries

Recent developments in high-performance cathodes for sodium-ion batteries (SIBs) tend to mitigate use of critical Ni and Co active species to satisfy sustainability. P2-type layered oxide cathodes based on Mn and Fe promise high capacity, sustainability, and low cost on account of the abundance and multiple redox characteristics of Mn and Fe. However, their commercialization is still challenged due to poor cycling stability caused by phase changes emanating from inherent Jahn-Teller distortions. Herein, we propose a novel strategy of trivalent La and Al co-doping to alleviate the drawbacks, innovating a new cathode of Na 0.67 Mn 0.62 Al 0.05 Fe 0.31 La 0.02 O 2 (AlLa). The co-doped cathode delivers an impressive capacity of 128.7 mAh/g at 1C and 106.5 mAh/g at high rate of 5C with a good capacity retention of 85% after 100 cycles. These are superior to the unmodified material, whose specific capacity was 118.6 mAh/g at 1C and 61.1 mAh/g at 5C with a retention of only 65% after 100 cycles. The synergistic contribution from La and Al associated with their improved oxygen bonding, pillaring, and local electronic structural modification stemming from rigid Lasingle bondO and Alsingle bondO bonding resulted in the observed structural and electrochemical improvement. Overall, this research offers novel strategies for designing high-performance cathode materials for sodium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2020

Interfacial engineering for stabilizing polymer electrolytes with 4V cathodes in lithium metal batteries at elevated temperature

Poly (ethylene oxide) (PEO) polymer electrolytes are promising candidates for next-generation rechargeable lithium batteries. However, the poor interfacial stability between 4 V cathodes and PEO electrolytes impedes their applications in 4 V lithium batteries with high energy density. Here, we demonstrate a facile and effective strategy to enhance the interfacial stability by the synergy of Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) coating on the cathode surface, and salt combination in the electrolyte, even with a cut-off voltage of 4.25–4.4 V vs. Li + /Li. Nano-LAGP coated Li|PEO|LiCoO 2 cell delivers stable cycling with a capacity retention of 81.9%/400 cycles and 84.7%/200 cycles at 60 °C when charged to 4.25 and 4.3 V in pure polyether electrolyte, respectively. Steady cycling is also demonstrated at room temperature and with LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) cathode. This work offers a viable and scalable approach to improve the stability between PEO electrolytes and 4 V cathodes and open up new possibilities for practical application of 4 V lithium metal batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Cation Vacancies Enable Anion Redox in Li Cathodes

Conventional Li-ion battery intercalation cathodes leverage charge compensation that is formally associated with redox on the transition metal. Employing the anions in the charge compensation mechanism, so-called anion redox, can yield higher capacities beyond the traditional limitations of intercalation chemistry. Here, we aim to understand the structural considerations that enable anion oxidation and focus on processes that result in structural changes, such as the formation of persulfide bonds. Using a Li-rich metal sulfide as a model system, we present both first-principles simulations and experimental data that show that cation vacancies are required for anion oxidation. First-principles simulations show that the oxidation of sulfide to persulfide only occurs when a neighboring vacancy is present. To experimentally probe the role of vacancies in anion redox processes, we introduce vacancies into the Li 2 TiS 3 phase while maintaining a high valency of Ti. When the cation sublattice is fully occupied and no vacancies can be formed through transition metal oxidation, the material is electrochemically inert. Upon introduction of vacancies, the material can support high degrees of anion redox, even in the absence of transition metal oxidation. The model system offers fundamental insights to deepen our understanding of structure–property relationships that govern reversible anion redox in sulfides and demonstrates that cation vacancies are required for anion oxidation, in which persulfides are formed.

25 ENERGY STORAGE↗
DOE OSTI2022

Effect of Electrolytes on the Cathode-Electrolyte Interfacial Stability of Fe-Based Layered Cathodes for Sodium-Ion Batteries

Iron (Fe)-based layered oxide cathodes that employ Fe 3+ /Fe 4+ redox reaction present a family of attractive cathode materials for sodium-ion batteries as iron is abundant, low-cost, and environmentally benign. However, their electrochemical performance is not yet satisfactory and requires further improvement. In this study, we investigate the effect of electrolytes on the electrochemical performance of α -NaFeO 2 , a prototypical model of Fe-based layered cathodes. First, we established the critical impact of the poor cathode-electrolyte interfacial stability on cell performances. Systematic electrochemical tests and material characterizations further revealed the degradation mechanism in which the highly reactive Fe 4+ state in the charged Na 1−x FeO 2 electrodes promotes severe electrolyte decomposition and subsequent growth of a thick interface layer that leads to impedance rise and performance degradation. In addition, the superior performance of NaPF 6 over NaClO 4 and the beneficial effect of the FEC additive are reported.

25 ENERGY STORAGE↗
DOE OSTI2020

Encapsulated sulfur cathodes for rechargeable lithium batteries

A method of forming a sulfur-based cathode material includes: 1) providing a sulfur-based nanostructure; 2) coating the nanostructure with an encapsulating material to form a shell surrounding the nanostructure; and 3) removing a portion of the nanostructure through the shell to form a void within the shell, with a remaining portion of the nanostructure disposed within the shell.

25 ENERGY STORAGE↗
DOE OSTI2021

Encapsulated sulfur cathodes for rechargeable lithium batteries

A method of forming a sulfur-based cathode material includes: 1) providing a sulfur-based nanostructure; 2) coating the nanostructure with an encapsulating material to form a shell surrounding the nanostructure; and 3) removing a portion of the nanostructure through the shell to form a void within the shell, with a remaining portion of the nanostructure disposed within the shell.

Li, Weiyang↗