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At least 199 records · Page 11

Facile synthesis of fusiform layered oxides assisted by microwave as cathode material for lithium-ion batteries

Graphical abstract: Fusiform layered oxides synthesized by microwave solvothermal reaction with excellent electrochemical property as cathode material for lithium-ion batteries. - Highlights: • LiMn{sub 0.25}Ni{sub 0.5}Co{sub 0.25}O{sub 2} is obtained by microwave solvothermal reaction. • Material synthesized at 800 °C exhibits fusiform hierarchical morphology. • High initial discharge capacity of 183 mAh g{sup −1} is reached at 0.1C. • 154 mAh g{sup −1} is remained with a capacity retention of 84.2% after 100 cycles. • Excellent rate capability is also obtained. - Abstract: A facile microwave solvothermal reaction is performed to synthesize novel LiMn{sub 0.25}Ni{sub 0.5}Co{sub 0.25}O{sub 2} ternary layered oxide with 1 D fusiform morphology. Scanning electron microscopy (SEM) images show that material synthesized at 800 °C well keeps the fusiform morphology of the precursor with a particle size of 100–300 nm. All the three elements are perfectly dispersed and a well-formed layered structure is obtained. Thus, good electrochemical performances with high initial discharge capacity of 183 mAh g{sup −1} is reached. Furthermore, high discharge capacity of 154 mAh g{sup −1} is remained with a capacity retention of 84.2% after 100 cycles at 20 mA g{sup −1}. Excellent rate capability is also obtained with high discharge capacity of 99 mAh g{sup −1} at 2000 mA g{sup −1}. It seems such facile microwave solvothermal method is one of the most promising candidates for preparing ternary layered oxides with excellent electrochemical properties as cathode material for lithium ion batteries.

36 MATERIALS SCIENCE↗

Evaluation of Cathode Materials with Lithium-Metal Anodes: Baseline Performance and Protocol Standardization of Coin Cells

The collaborative evaluation of electrode materials across multiple research entities requires standardized electrochemical testing protocols to produce reliable, one-to-one comparisons between different systems of interest. Similar to the work done by Long et al. on protocol standardization for coin-cell testing with graphite anodes [J. Electrochem. Soc., 163, A2999, (2016)], here we introduce two standardized testing protocols designed to quickly evaluate important electrochemical properties of cathode materials using lithium-metal anodes. The two protocols measure kinetic and thermodynamic capacity losses, rate- and voltage-dependent cycling capacities, instabilities at high voltage and high cycling rate, and overpotentials at various states of charge. We then apply these protocols to four commercially available cathode materials to establish benchmark performance metrics that can be used to screen and evaluate new cathode materials.

25 ENERGY STORAGE↗

Surface Characterization of Li-Substituted Compositionally Heterogeneous NaLi 0.045 Cu 0.185 Fe 0.265 Mn 0.505 O 2 Sodium-Ion Cathode Material

The understanding of surface chemical and structural processes can provide some insights into designing stable sodium cathode materials. Herein, Li-substituted and compositionally heterogeneous NaLi 0.045 Cu 0.185 Fe 0.265 Mn 0.505 O 2 is used as a platform to investigate the interplay between Li substitution, surface chemistry, and battery performance. Li substitution improves the initial discharge capacity and energy density. Yet, there is no noticeable benefit in the long-term cycling stability of this material. The Li substitution in the transition-metal (TM) layer also seems to influence the transition-metal (TM) 3d–oxygen (O) 2p hybridization. Upon desodiation, the surface of active particles undergoes significant transition-metal reduction, especially Mn. Furthermore, the presence of electrolyte drastically accelerates such surface degradation. In general, the Li-substituted material experiences severe surface degradation, which is partially responsible for the performance degradation upon long-term cycling. While some studies have introduced the benefits of Li substitution, the present study suggests that the effectiveness of the Li substitution strategy depends on the TM compositional distribution. More efforts are needed to improve the surface chemistry of Li-substituted sodium cathode materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Improving the oxygen redox reversibility of Li-rich battery cathode materials via Coulombic repulsive interactions strategy

The oxygen redox reaction in lithium-rich layered oxide battery cathode materials generates extra capacity at high cell voltages (i.e., >4.5 V). However, the irreversible oxygen release causes transition metal (TM) dissolution, migration and cell voltage decay. To circumvent these issues, we introduce a strategy for tuning the Coulombic interactions in a model Li-rich positive electrode active material, i.e., Li 1.2 Mn 0.6 Ni 0.2 O 2 . In particular, we tune the Coulombic repulsive interactions to obtain an adaptable crystal structure that enables the reversible distortion of TMO 6 octahedron and mitigates TM dissolution and migration. Moreover, this strategy hinders the irreversible release of oxygen and other parasitic reactions (e.g., electrolyte decomposition) commonly occurring at high voltages. When tested in non-aqueous coin cell configuration, the modified Li-rich cathode material, combined with a Li metal anode, enables a stable cell discharge capacity of about 240 mAh g -1 for 120 cycles at 50 mA g -1 and a slower voltage decay compared to the unmodified Li 1.2 Mn 0.6 Ni 0.2 O 2 .

25 ENERGY STORAGE↗

Impacts of Lanthanum Impurities on Nickel-Rich Cathode Materials

The widespread use of lithium-ion batteries (LIBs) has led to environmental concerns and exacerbated the scarcity of essential minerals, underscoring the urgent need for effective recycling strategies. Among various recycling methods, the hydrometallurgical process is distinguished by its energy efficiency and minimal environmental impact. Nickel-metal hydride (Ni-MH) batteries are a significant source of nickel sulfate (NiSO 4 ) for hydrometallurgical recycling due to their substantial nickel content. A significant challenge arises from the effective separation of lanthanum (La), which results in at least 20 ppm of La being present in the recycled NiSO 4 . This study explores a critical aspect of the recycling process: the impact of La 3+ impurities, introduced through recycled NiSO 4 , on the performance of the synthesized nickel-rich cathode materials. We conducted a thorough investigation into how La 3+ influences morphology and structural integrity during both the synthesis of precursors and the production of cathode materials. Our findings indicate that La 3+ impurities do not adversely affect the morphology or structural integrity of the cathode precursors relative to virgin materials. However, higher concentrations of La 3+ reduce the discharge capacity with enhanced cycle stability by minimizing cation mixing between lithium (Li + ) and nickel (Ni 2+ ) ions within the cathode. Furthermore, this stability is crucial for extending battery life. Therefore, controlling the concentration of La 3+ impurities is essential for optimizing the electrochemical performance of recycled cathode materials.

Corrosion↗

Effect of Cationic (Na + ) and Anionic (F – ) Co-Doping on the Structural and Electrochemical Properties of LiNi 1/3 Mn 1/3 Co 1/3 O 2 Cathode Material for Lithium-Ion Batteries

Elemental doping for substituting lithium or oxygen sites has become a simple and effective technique to improve the electrochemical performance of layered cathode materials. Compared with single-element doping, this work presents an unprecedented contribution to the study of the effect of Na + /F – co-doping on the structure and electrochemical performance of LiNi 1/3 Mn 1/3 Co 1/3 O 2 . The co-doped Li 1-z Na z Ni 1/3 Mn 1/3 Co 1/3 O 2-z F z (z = 0.025) and pristine LiNi 1/3 Co 1/3 Mn 1/3 O 2 materials were synthesized via the sol–gel method using EDTA as a chelating agent. Structural analyses, carried out by X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy, revealed that the Na + and F – dopants were successfully incorporated into the Li and O sites, respectively. The co-doping resulted in larger Li-slab spacing, a lower degree of cation mixing, and the stabilization of the surface structure, which substantially enhanced the cycling stability and rate capability of the cathode material. The Na/F co-doped LiNi 1/3 Mn 1/3 Co 1/3 O 2 electrode delivered an initial specific capacity of 142 mAh g –1 at a 1C rate (178 mAh g –1 at 0.1C), and it maintained 50% of its initial capacity after 1000 charge–discharge cycles at a 1C rate.

25 ENERGY STORAGE↗

High-Capacity, High-Voltage Composite Oxide Cathode Materials

This SBIR project integrates theoretical and experimental work to enable a new generation of high-capacity, high-voltage cathode materials that will lead to high-performance, robust energy storage systems. At low operating temperatures, commercially available electrode materials for lithium-ion (Li-ion) batteries do not meet energy and power requirements for NASA's planned exploration activities. NEI Corporation, in partnership with the University of California, San Diego, has developed layered composite cathode materials that increase power and energy densities at temperatures as low as 0 degC and considerably reduce the overall volume and weight of battery packs. In Phase I of the project, through innovations in the structure and morphology of composite electrode particles, the partners successfully demonstrated an energy density exceeding 1,000 Wh/kg at 4 V at room temperature. In Phase II, the team enhanced the kinetics of Li-ion transport and electronic conductivity at 0 degC. An important feature of the composite cathode is that it has at least two components that are structurally integrated. The layered material is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated and deliver a large amount of energy with stable cycling.

Hagh, Nader M.↗

Oxygen Release Degradation in Li–Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches

Widespread application of Li–ion batteries (LIBs) in large–scale transportation and grid storage systems requires highly stable and safe performance of the batteries in prolonged and diverse service conditions. Oxygen release from oxygen–containing positive electrode materials is one of the major structural degradations resulting in rapid capacity/voltage fading of the battery and triggering the parasitic thermal runaway events. Herein, the authors summarize the recent progress in understanding the mechanisms of the oxygen release phenomena and correlative structural degradations observed in four major groups of cathode materials: layered, spinel, olivine, and Li–rich cathodes. In addition, the engineering and materials design approaches that improve the structural integrity of the cathode materials and minimize the detrimental O 2 evolution reaction are summarized. As a result, the authors believe that this review can guide researchers on developing mitigation strategies for the design of next–generation oxygen–containing cathode materials where the oxygen release is no longer a major degradation issue.

25 ENERGY STORAGE↗

Understanding High-Voltage Behavior of Sodium-Ion Battery Cathode Materials Using Synchrotron X-ray and Neutron Techniques: A Review

Despite substantial research efforts in developing high-voltage sodium-ion batteries (SIBs) as high-energy-density alternatives to complement lithium-ion-based energy storage technologies, the lifetime of high-voltage SIBs is still associated with many fundamental scientific questions. In particular, the structure phase transition, oxygen loss, and cathode–electrolyte interphase (CEI) decay are intensely discussed in the field. Synchrotron X-ray and neutron scattering characterization techniques offer unique capabilities for investigating the complex structure and dynamics of high-voltage cathode behavior. In this review, to accelerate the development of stable high-voltage SIBs, we provide a comprehensive and thorough overview of the use of synchrotron X-ray and neutron scattering in studying SIB cathode materials with an emphasis on high-voltage layered transition metal oxide cathodes. We then discuss these characterizations in relation to polyanion-type cathodes, Prussian blue analogues, and organic cathode materials. Finally, future directions of these techniques in high-voltage SIB research are proposed, including CEI studies for polyanion-type cathodes and the extension of neutron scattering techniques, as well as the integration of morphology and phase characterizations.

25 ENERGY STORAGE↗

Advanced Manufacturing of Cathode Materials for Lithium-ion Batteries

Original objectives (per the Statement of Project Objectives) centered on developing and translating a continuous pilot process for cathode materials production while targeting (i) a 29% manufacturing cost reduction, (ii) an 82% energy consumption reduction for cathode production, and (iii) a doubling of manufacturing productivity. Planned validation included characterization at appropriate analytical facilities and electrochemical performance evaluation progressing from half-cells to pouch-cell formats, with a pathway to kilogram-scale production of finished cathode materials for representative testing. Scope evolution: During execution, the project team identified that the surfactant-enabled chemistry offered high selectivity for lithium precipitation from brine sources. A formal scope revision shifted the final project year from cathode manufacturing development to direct lithium extraction/lithium recovery, while maintaining the overarching intent of cost reduction and process simplification relevant to the battery supply chain.

25 ENERGY STORAGE↗

Temperature-Swing Synthesis of Large-Size Single-Crystal LiNi 0.6 Mn 0.2 Co 0.2 O 2 Cathode Materials

Single-crystal lithium-nickel-manganese-cobalt-oxide (SC-NMC) has recently emerged as a promising battery cathode material due to its outstanding cycle performance and mechanical stability over the tradional polycrystalline NMC. It is favorable to further increase the grain size of SC-NMC particles to achieve a higher volumetric energy density and minimize surface-related degradations. However, the preparation of large-size yet high performance SC-NMC particles faces a challenge in choosing a suitable temperature for sintering. High temperature promotes grain growth but induces cation mixing that negatively impacts the electrochemical performance. Here we report a temperature-swing sintering (TSS) strategy with two isothermal stages that fulfils the needs for grain growth and structural ordering sequentially. A high-temperature sintering is first used for a short period of time to increase grain size and then the reaction temperature is lowered and kept constant for a longer period of time to improve structural ordering and complete the lithiation process. SC-LiNi 0.6 Mn 0.2 Co 0.2 O 2 materials prepared via TSS exhibit large grain size (~4 μm), a low degree of cation mixing (~0.9%), and outperform the control samples prepared by the conventional sintering method. Furthermore, this work highlights the importance of understanding the process-structure-property relationships and may guide the synthesis of other SC Ni-rich cathode materials.

25 ENERGY STORAGE↗

Li-Substituted Layered-Spinel Cathode Material for Sodium-Ion Batteries

The O 3 -type layered Na(Ni x Fe y Mn z )O 2 (0 < x, y, z < 1) cathode materials have attracted great interest in sodium ion batteries due to the abundance and cost of raw materials and their high specific capacities. However, the cycling stability and rate capability at high voltages (> 4.0 V) of these materials remain an issue. In this work, we successfully synthesized a Li-substituted layered-tunneled (O 3 -spinel) intergrowth cathode (LS-NFM) to address these issues. The remarkable structural compatibility and connectivity of the two phases were confirmed by X-ray diffraction (XRD), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). The LS-NFM electrode reached a discharge capacity of 96 mAh g -1 with a capacity retention of 86% after 100 cycles at a current rate of 100 mA g -1 in a voltage window of 2.0-4.2 V. Moreover, the LS-NFM cathode exhibited an enhanced rate capability in comparison to the undoped single-phased layered cathode (NFM). The enhanced rate capability of LS-NFM can be explained by the significantly increased effective Na + diffusivity measured by the galvanostatic intermittent titration technique (GITT) compared to the undoped control NFM cathode, which can be ascribed to the improved charge transport kinetics through shortened diffusion path by direct connection between the 3D channels in the spinel phase and 2D channels in the layered phase. The results from ex situ hard/soft X-ray adsorption spectroscopy (XAS) suggest that the capacity of the LS-NFM cathode is mainly associated with the Ni 2+ /Ni 4+ redox couple and slightly from the Fe 3+ /Fe 4+ redox couple. The voltage profile of the LS-NFM cathode exhibits a reversible plateau above 4.0 V, indicating great stability at high voltages and structural stabilization by the spinel phase. In addition to the substitution of various transition metals, or the modification of the stoichiometry of each transition metal, this study provides a new strategy to improve electrochemical performance of layered cathode materials for sodium ion batteries.

25 ENERGY STORAGE↗

Understanding Reactivities of Ni-rich Li[NixMnyCo1-x-y]O2 Single-Crystal Cathode Materials

While Ni-rich Li[NixMnyCo1-x-y]O2 (NMC, x ? 0.8) compounds are considered the most promising cathode materials for high-energy lithium-ion batteries (LIBs), a significant challenge is the higher reactivities caused by the increased Ni content, especially under high-voltage operation conditions. In the present study, we synthesize three single-crystal NMC (SC-NMC) samples with the same particle size and morphology: LiNi0.8Mn0.1Co0.1O2 (NMC811), LiNi0.80Mn0.15Co0.05O2 (NMC80155) and LiNi0.85Mn0.10Co0.05O2 (NMC85105). By systematically varying the composition while controlling other properties, the role of each transition metal during air exposure, thermal treatment and long-term cycling is clearly demonstrated. We reveal that while higher Ni content leads to an overall increased reactivities, the presence of Mn provides a stabilizing effect on thermal, structural and chemical properties. In the absence of cycling-induced particle cracking, surface reconstruction is shown to be the dominating contributor to cathode capacity fade. Our study provides key insights needed for the development of better-performing Ni-rich NMC cathode materials.

Kim, Minkyung↗

Cathode material for lithium batteries

A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

25 ENERGY STORAGE↗

Cathode material for lithium batteries

A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

25 ENERGY STORAGE↗

An Effective Relithiation Process for Recycling Lithium‐Ion Battery Cathode Materials

Abstract Rapid adoption of lithium‐ion batteries for electronics and electric vehicles requires cost‐effective and efficient recycling of battery components especially the valuable cathode active materials. The direct recycling method transforms end‐of‐life (EOL) cathode materials into battery grade materials with minimal energy consumption and least environmental disruption. In direct recycling, the relithiation step to restore the lithium stoichiometry of the cathode materials is critical. In this work, a novel electrochemical relithiation approach in an aqueous electrolyte followed by a heat treatment for recycling cathode materials in EOL lithium‐ion batteries is demonstrated and analyzed. Using LiCoO 2 as an example, it is shown that the recycled LiCoO 2 materials show equivalent crystal structure, morphology, and electrochemical performance to the commercial LiCoO 2 .

Yang, Tairan↗

Mitigating oxygen loss to improve the cycling performance of high capacity cation-disordered cathode materials

Recent progress in the understanding of percolation theory points to cation-disordered lithium-excess transition metal oxides as high-capacity lithium-ion cathode materials. Nevertheless, the oxygen redox processes required for these materials to deliver high capacity can trigger oxygen loss, which leads to the formation of resistive surface layers on the cathode particles. Here, we demonstrate here that, somewhat surprisingly, fluorine can be incorporated into the bulk of disordered lithium nickel titanium molybdenum oxides using a standard solid-state method to increase the nickel content, and that this compositional modification is very effective in reducing oxygen loss, improving energy density, average voltage, and rate performance. We argue that the valence reduction on the anion site, offered by fluorine incorporation, opens up significant opportunities for the design of high-capacity cation-disordered cathode materials.

25 ENERGY STORAGE↗

Development of Low Cost, Robust and Durable Cathode Materials to Support Solid Oxide Fuel Cell Commercialization (Final Technical Report)

The project is aimed at addressing critical issues related to chromia-poisoning in the cathode of solid oxide fuel cells. A technical hurdle to the commercialization of solid oxide fuel cells is that chromia sources from the metallic interconnect and the balance of plant (BoP) components will cause chromia-poisoning to the cathode performance. This presents a significant challenge since it is very difficult to eliminate chromia sources in the cathode environment. One aspect of the current project is to evaluate whether SFM (Sr 2 Fe 1.5 Mo 0.5 O 6-δ ) that we have recently developed as redox-stable mixed conducting oxide possesses tolerance to chromia-poisoning. The second focus of this project is to evaluate coating on the cathode materials to mitigate chromia poisoning effect. Both thermodynamic evaluation and experimental approaches have been applied to enhance the knowledge base and fundamental understanding of chromia-tolerance of cathode for solid oxide fuel cells. low cost, robust and durable cathode material to support SOFC commercialization.

30 DIRECT ENERGY CONVERSION↗