Modifying Metastable Sr 1– x BO 3−δ (B = Nb, Ta, and Mo) Perovskites for Electrode Materials
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Atom probe results of the NMC811 sample from an ultra-high vacuum vs. air transferring.
The use of polycrystalline silicon in charged coupled semiconductor devices is discussed. In particular, the electrical and optical properties of the material are characterized.
The work function determinations of candidate materials for low temperature (1400 K) thermionics through vacuum emission tests are discussed. Two systems, a vacuum emission test vehicle and a thermionic emission microscope are used for emission measurements. Some nickel and cobalt based super alloys were preliminarily examined. High temperature physical properties and corrosion behavior of some super alloy candidates are presented. The corrosion behavior of sodium is of particular interest since topping cycles might use sodium heat transfer loops. A Marchuk tube was designed for plasma discharge studies with the carbide and possibly some super alloy samples. A series of metal carbides and other alloys were fabricated and tested in a special high temperature mass spectrometer. This information coupled with work function determinations was evaluated in an attempt to learn how electron bonding occurs in transition alloys.
Preparation, characterization, and an electrochemical study of Mg 0.1 V 2 O 5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage ˜3.2 Volts with an energy density ˜800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.
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Preparation, characterization, and an electrochemical study of Mg 0.1 V 2 O 5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage ˜3.2 Volts with an energy density ˜800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.
A stabilized lithium metal oxide cathode material comprises microparticles of lithium metal oxide in which individual particles thereof a core of lithium metal oxide and a coating of a different lithium metal oxide surrounding the core. There is an interface layer between the cores and the coatings in which there are gradients of metal ions in the direction of coating to core. The materials are made by a three stage process involving coprecipitating precursor metal hydroxide core particles at a controlled pH; coprecipitating a different metal hydroxide coating on the particles without controlling the pH; and then calcining the resulting coated precursor particles with lithium hydroxide to form the stabilized lithium metal oxide material.
Abstract not provided.
A stabilized lithium metal oxide cathode material comprises microparticles of lithium metal oxide in which individual particles thereof a core of lithium metal oxide and a coating of a different lithium metal oxide surrounding the core. There is an interface layer between the cores and the coatings in which there are gradients of metal ions in the direction of coating to core. The materials are made by a three stage process involving coprecipitating precursor metal hydroxide core particles at a controlled pH; coprecipitating a different metal hydroxide coating on the particles without controlling the pH; and then calcining the resulting coated precursor particles with lithium hydroxide to form the stabilized lithium metal oxide material.
A method for recycling lithium-ion battery materials is provided. The method includes isolating a composite electrode comprising an electrode material adhered to a current collector with a polyvinylidene difluoride (PVDF) binder. The composite electrode is combined with triethyl phosphate (TEP) as a solvent to form a mixture. The electrode material is delaminated from the current collector in the mixture to give a free electrode material and a free current collector. Each of the free electrode material and the free current collector is recovered from the mixture. The free electrode material may be reused to prepare another composite electrode, as well as a lithium-ion battery comprising the same, which are also disclosed.
A battery includes negative electrode material and positive electrode material where the materials are in a solid phase except for selected portions that are heated to transform the selected portions into a fluid. The fluid portion of negative electrode material is directed to a negative electrode region of a reaction chamber and the fluid portion of positive electrode material is directed to a positive electrode region of the reaction chamber where a solid electrolyte containing ions of the negative electrode separates the positive electrode region from the negative electrode region.
An electrode material includes a lithium active material composition. The lithium active material composition includes lithium and an active anode material. The lithium active material composition is coated with a lithium ion conducting passivating material, such that the electrode material is lithiated and pre-passivated. An electrode and a battery are also disclosed. Methods of making an electrode material, electrode and battery that are lithiated and pre-passivated are also disclosed.
In recent years, graphene-type materials originating from metal–organic frameworks (MOFs) or integrated with MOFs have exhibited notable performances across various applications. However, a comprehensive understanding of these complex materials and their functionalities remains obscure. While some studies have reviewed graphene/MOF composites from different perspectives, due to their structural–functional intricacies, it is crucial to conduct more in-depth reviews focusing on specific sets of graphene/MOF composites designed for particular applications. In this review, we thoroughly investigate the syntheses, characteristics, and performances of N-G/MOF(ZIF-8)-based/derived materials employed in electrochemical energy conversion and storage systems. Special attention is given to realizing their fundamental functionalities. The discussions are divided into three segments based on the application of N-G/ZIF-8-based/derived materials as electrode materials for batteries, electrodes for electrochemical capacitors, and electrocatalysts. As electrodes for batteries, N-G/MOF(ZIF-8) materials can mitigate issues like an electrode volume expansion for Li-ion batteries and the ‘shuttle effect’ for Li-S batteries. As electrodes for electrochemical capacitors, these materials can considerably improve the ion transfer rate and electronic conductivity, thereby enhancing the specific capacitance while maintaining the structural stability. Also, it was observed that these materials could occasionally outperform standard platinum-based catalysts for the electrochemical oxygen reduction reaction (ORR). The reported electrochemical performances and structural parameters of these materials were carefully tabulated in uniform units and scales. Through a critical analysis of the present synthesis trends, characteristics, and functionalities of these materials, specific aspects were identified that required further exploration to fully utilize their inherent capabilities.
The gaseous environment that battery electrodes are exposed to is critical to their electrochemical performance, and yet, the impact of vapor-phase components in the glovebox is relatively unexplored. In this study, we examine how the surface of Li 4 Ti 5 O 12 and LiFePO 4 composite electrodes evolve upon exposure to 1 M LiPF 6 in ethylene carbonate:dimethyl carbonate electrolyte vapors in an argon-filled glovebox. Spatially resolved X-ray photoemission electron microscopy and X-ray photoelectron spectroscopy reveal that even brief (15 minutes) contact with electrolyte vapor initiates the formation of a LiF film and changes the oxidation state of transition metals at the particle surface. Notably, these modifications occur selectively on active material particles and not on binder or conductive carbon, underscoring the specificity of vapor-induced reactions. Prolonged exposure to electrolyte vapor over the course of 1 week yields thicker, more chemically complex interphases containing both LiF and lithium oxyfluorophosphate species (Li x PO y F z ). Subsequent electrochemical testing shows that vapor-induced passivation layers influence first cycle capacities, lithium (de)insertion overpotentials, and charge-transfer resistance values. In conclusion, these results indicate that vapor–electrode interactions may be a source of variability in electrochemical behavior over time and suggest that other, more reactive electrode materials may also be susceptible to interactions with electrolyte vapor.
Conversion-type electrode materials for lithium-ion batteries experience significant structural changes during the first discharge–charge cycle, where a single particle is taken apart into a number of nanoparticles. This structural evolution may affect the following lithium insertion reactions; however, how lithiation occurs in pre-cycled electrode materials is elusive. In this work, in situ transmission electron microscopy was employed to see the lithium-induced structural and chemical evolutions in pre-cycled nickel oxide as a model system. The introduction of lithium ions induced the evolution of metallic nickel, with volume expansion as a result of a conversion reaction. After pre-cycling, the phase evolutions occurred in two separate areas almost at the same time. This is different from the first lithiation, where the phase change takes place successively, with a boundary dividing the reacted and unreacted areas. Structural changes were restricted at the areas having large amount of fluorine, implying the residuals from the decomposition of electrolytes may have hindered the electrochemical reactions. This work provides insights into phase and chemical evolutions in pre-cycled conversion-type materials, which govern electrochemical properties during operation.