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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 271 records · Page 15

Performance of Different Water-Based Binder Formulations for Ni-Rich Cathodes Evaluated in LiNi 0.8 Mn 0.1 Co 0.1 O 2 //Graphite Pouch Cells

Water-based processing for lithium-ion battery electrodes is attractive due to its lower manufacturing cost and smaller environmental impact. However, multiple challenges associated with aqueous cathode processing have hindered commercial adoption. Polymer binders are an important component of the electrode, and thus the choice of binders can alter electrode cycling performance significantly. In this work, four different water-based binder combinations are investigated for Ni-rich LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811)-based cathodes, with a focus on the long-term electrochemical performance in practical-format full pouch cells. No additional pH-modulating additives were added to the aqueous cathode slurries, and no protective coatings were present on the cathode or aluminum current collector. Results are compared with the standard PVDF/NMP-based binder/solvent combination, used as a baseline. The influence of water-based binder type on slurry rheology and electrode microstructure are also discussed. All cells made by water-processing had worse rate performance compared to the baseline. However, the cell discharge capacity after 1000 U.S. Advanced Battery Consortium (USABC) cycles at C/3 charge/discharge rate was comparable to the baseline for two of the water-based cathode formulations (CMC & JSR, and LiPAA), demonstrating the potential viability of aqueous-processed Ni-rich cathodes at a commercial scale.

25 ENERGY STORAGE↗

Scaffolding matrix with internal nanoparticles

A battery electrode composition is provided comprising composite particles, with each composite particle comprising active material and a scaffolding matrix. The active material is provided to store and release ions during battery operation. For certain active materials of interest, the storing and releasing of the ions causes a substantial change in volume of the active material. The scaffolding matrix is provided as a porous, electrically-conductive scaffolding matrix within which the active material is disposed. In this way, the scaffolding matrix structurally supports the active material, electrically interconnects the active material, and accommodates the changes in volume of the active material.

Yushin, Gleb↗

Scaffolding matrix with internal nanoparticles

A battery electrode composition is provided comprising composite particles, with each composite particle comprising active material and a scaffolding matrix. The active material is provided to store and release ions during battery operation. For certain active materials of interest, the storing and releasing of the ions causes a substantial change in volume of the active material. The scaffolding matrix is provided as a porous, electrically-conductive scaffolding matrix within which the active material is disposed. In this way, the scaffolding matrix structurally supports the active material, electrically interconnects the active material, and accommodates the changes in volume of the active material.

25 ENERGY STORAGE↗

Scaffolding matrix with internal nanoparticles

A battery electrode composition is provided comprising composite particles, with each composite particle comprising active material and a scaffolding matrix. The active material is provided to store and release ions during battery operation. For certain active materials of interest, the storing and releasing of the ions causes a substantial change in volume of the active material. The scaffolding matrix is provided as a porous, electrically-conductive scaffolding matrix within which the active material is disposed. In this way, the scaffolding matrix structurally supports the active material, electrically interconnects the active material, and accommodates the changes in volume of the active material.

Yushin, Gleb↗

Deciphering the Oxygen Absorption Pre-edge: A Caveat on its Application for Probing Oxygen Redox Reactions in Batteries

The pre-edges of oxygen-K X-ray absorption spectra have been ubiquitous in transition metal (TM) oxide studies in various fields, especially on the fervent topic of oxygen redox states in battery electrodes. However, critical debates remain on the use of the O-K pre-edge variations upon electrochemical cycling as evidences of oxygen redox reactions, which has been a popular practice in the battery field. This study presents an investigation of the O-K pre-edge of 55 oxides covering all 3d TMs with different elements, structures, and electrochemical states through combined experimental and theoretical analyses. It is shown unambiguously that the O-K pre-edge variation in battery cathodes is dominated by changing TM-d states. Furthermore, the pre-edge enables a unique opportunity to project the lowest unoccupied TM-d states onto one common energy window, leading to a summary map of the relative energy positions of the low-lying TM states, with higher TM oxidation states at lower energies, corresponding to higher electrochemical potentials. The results naturally clarify some unusual redox reactions, such as Cr 3+/6+ . This work provides a critical clarification on O-K pre-edge interpretation and more importantly a benchmark database of O-K pre-edge for characterizing redox reactions in batteries and other energy materials.

36 MATERIALS SCIENCE↗

Three-dimensional phase evolution and stress-induced non-uniform Li intercalation behavior in lithium iron phosphate

A lithium iron phosphate (LiFePO 4 ) olivine cathode displays rich phase transition behavior during charging/discharging. Despite extensive studies, the evolution of the LiFePO 4 /FePO 4 two-phase coexistence structure and the underlying mechanism are still a point of debate due to the intricate and often disparate phase morphologies observed. Here we apply phase-field simulations to provide detailed insights into the three-dimensional phase evolution process in LiFePO 4 upon delithiation under a large driving force. The simulation reveals that the coherency stress arising from the LiFePO 4 /FePO 4 lattice mismatch destabilizes the initially flat delithiation front and induces filamentary growth of the FePO 4 phase along [010], which is in excellent agreement with a recent operando X-ray imaging study. The combined simulation and experimental results provide the first illustration of the phenomenon of stress-induced instability of the lithium (de)intercalation front in battery electrode compounds. We show that this phenomenon is facilitated by the surface mode of coherent spinodal decomposition in LiFePO 4 and influenced by the anisotropies of misfit strain, elasticity and lithium diffusion. It is detrimental to battery performance and life by causing stress concentration and reducing the lithium (de)intercalation kinetics and thus should be mitigated.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Solid-state polymer-particle hybrid electrolytes: Structure and electrochemical properties

Solid-state electrolytes (SSEs) are challenged by complex interfacial chemistry and poor ion transport through the interfaces they form with battery electrodes. Here, we investigate a class of SSE composed of micrometer-sized lithium oxide (Li 2 O) particles dispersed in a polymerizable 1,3-dioxolane (DOL) liquid. Ring-opening polymerization (ROP) of the DOL by Lewis acid salts inside a battery cell produces polymer-inorganic hybrid electrolytes with gradient properties on both the particle and battery cell length scales. These electrolytes sustain stable charge-discharge behavior in Li||NCM811 and anode-free Cu||NCM811 electrochemical cells. On the particle length scale, Li 2 O retards ROP, facilitating efficient ion transport in a fluid-like region near the particle surface. On battery cell length scales, gravity-assisted settling creates physical and electrochemical gradients in the hybrid electrolytes. By means of electrochemical and spectroscopic analyses, we find that Li 2 O particles participate in a reversible redox reaction that increases the effective CE in anode-free cells to values approaching 100%, enhancing battery cycle life.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Selective cobalt and nickel electrodeposition for lithium-ion battery recycling through integrated electrolyte and interface control

Abstract Molecularly-selective metal separations are key to sustainable recycling of Li-ion battery electrodes. However, metals with close reduction potentials present a fundamental challenge for selective electrodeposition, especially for critical elements such as cobalt and nickel. Here, we demonstrate the synergistic combination of electrolyte control and interfacial design to achieve molecular selectivity for cobalt and nickel during potential-dependent electrodeposition. Concentrated chloride allows for the speciation control via distinct formation of anionic cobalt chloride complex (CoCl 4 2- ), while maintaining nickel in the cationic form ([Ni(H 2 O) 5 Cl] + ). Furthermore, functionalizing electrodes with a positively charged polyelectrolyte (i.e., poly(diallyldimethylammonium) chloride) changes the mobility of CoCl 4 2- by electrostatic stabilization, which tunes cobalt selectivity depending on the polyelectrolyte loading. This strategy is applied for the multicomponent metal recovery from commercially-sourced lithium nickel manganese cobalt oxide electrodes. We report a final purity of 96.4 ± 3.1% and 94.1 ± 2.3% for cobalt and nickel, respectively. Based on a technoeconomic analysis, we identify the limiting costs arising from the background electrolyte, and provide a promising outlook of selective electrodeposition as an efficient separation approach for battery recycling.

36 MATERIALS SCIENCE↗

High-dimensional and high-resolution x-ray tomography for energy materials science

At the forefront of developments in synchrotron x-ray microscopy, we report nanoscale-resolution high-dimensional spectrotomography under controlled sample environments has been demonstrated. Such cutting-edge experimental capability has been broadly applied to scientific studies in the field of energy materials science, where the dynamically evolving structural and chemical defects play a vital role in the functionality. In this article, we review novel developments of this technique from both experimental and data/information mining perspectives. Using studies on lithium-ion battery electrode materials as examples, we highlight the rich information in the high-dimensional and high-resolution x-ray tomographic data, which can be used to interpret the complicated thermal-electro-chemo-mechanical interplay that occurs under the operating conditions and collectively determines battery performance. We also discuss the frontier challenges in this field and our perspectives of the future directions in the context of projected major developments in the landscape of largescale x-ray facilities across the globe.

36 MATERIALS SCIENCE↗

Structure and lithium insertion in oxides of molybdenum

Oxides of molybdenum, MoO x , have a rich structural chemistry arising from the accommodation of oxygen deficiency as MoO 3 is reduced and varied redox behavior arising from the ability of Mo to take on several different oxidation states. We review MoO 3 , MoO 2 , and all the reduced Mo oxides with intermediate compositions for their performance as Li-ion battery electrode materials. These reduced oxides are perhaps the most structurally diverse in the field of energy storage materials, taking on structures ranging from ones with crystallographic shear to bronze-like structures and distorted rutile. The crystal structure can have a significant impact on the performance of battery materials, which makes the reduced Mo oxides a promising domain of study. Electrochemical studies of these oxides from as early as 1971 to as recently as 2022 are compiled, and characteristics of capacity, capacity retention, and rate performance are compared. We find that certain oxides indeed display promising and highly reversible capacities for Li + storage. Typical redox voltages for Mo oxides lie in a regime that hinders maximizing energy density when they are paired with higher-voltage cathodes or lower-voltage anodes. The possibility of decreasing the redox voltage in the future will expand the promise of these materials while offering an alternative to more critical elements such as Nb.

25 ENERGY STORAGE↗

Electromagnetic Energy-Assisted Thermal Conversion of Fossil-Based Hydrocarbons to Low-Cost Hydrogen

The goal of this project was to develop and optimize catalysts for methane decomposition, particularly focusing on regeneration via an electromagnetic energy-assisted mechanism, to produce hydrogen more cost-effectively compared to electrolysis routes. To achieve this goal, the project pursued several key objectives. The project began with the preparation and testing of various catalysts. A nickel-silica based catalyst was identified as the most promising material for the pyrolysis of methane into carbon and hydrogen. Kinetic parameters for methane decomposition were determined, aiding in computational modeling efforts. Structured catalysts were investigated, highlighting the need for frequent cleaning or regeneration to maintain performance, with methane conversion rates exceeding 70% in tube furnace tests. Computational fluid dynamics modeling was employed to optimize reactor designs and electrode angles, leading the project team to propose a multi-compartment thermal conversion system for larger setups. This modeling work was important in understanding reaction characteristics, carbon deposition rates, and temperature profiles under various conditions. A bench-scale reactor system was assembled to evaluate catalyst regeneration using electromagnetic energy-assisted mechanisms. Experiments demonstrated the potential for carbon removal, though further optimization is needed. The carbon produced from the methane conversion process was evaluated for potential use in lithium-ion battery electrodes. The carbon exhibited properties similar to commercially available high-purity multi-walled carbon nanotubes and nanofibers, with a carbon content greater than 95%. Coin cell batteries assembled with this carbon showed that lower replacement levels (10% to 33%) outperformed the control group, improving specific capacity density and stability. However, higher replacement levels (100%) demonstrated poorer performance, suggesting that excessive carbon substitution negatively impacts battery performance. These findings indicate the potential marketability of the produced carbon as a component in lithium-ion batteries, though further testing is necessary to confirm long-term advantages and disadvantages associated with the use of the carbon product. These results however justified further technoeconomic assessments to determine if the process can provide low-cost hydrogen. The economic feasibility and technical performance of methane decomposition for hydrogen production were assessed, focusing on three plant configurations: 100E (electrically heated), 100C (combustion heated using produced hydrogen), and PE-Hybrid (a combination of pyrolysis (indicating decomposition) and electrolysis). The Levelized Cost of Hydrogen (LCOH) for the pyrolysis configurations was found to be approximately 25% lower than that of electrolysis. The 100E configuration had the lowest LCOH at $\$$3.12/kg. Including carbon product sales significantly improved the economics, with the 100C configuration achieving a negative LCOH of -$\$$0.35/kg. The PE-Hybrid configuration was not economically advantageous compared to pure pyrolysis plants due to its complexity and additional equipment requirements. Ultimately, methane pyrolysis presents a viable method for near carbon dioxide-free hydrogen production, with significant economic advantages over electrolysis, especially when considering the sale of carbon byproducts. The 100E and 100C configurations showed the most promise, with the choice between them ultimately depending on the prices of power and natural gas. In conclusion, this technology has the potential to lower hydrogen production costs by leveraging the methane decomposition process with the sale of valuable carbon byproducts. By optimizing catalyst performance and integrating electromagnetic energy-assisted regeneration, the process can achieve higher efficiency and economic viability, making it a competitive alternative to traditional hydrogen production methods.

08 HYDROGEN↗

Utilizing Conjugated Imine Polymers to Stabilize Nanoparticle Silicon Anodes

Silicon anodes provide a compelling route towards delivering high-capacity lithium-ion batteries, however they are notoriously difficult to stabilize in conventional liquid electrolytes that are compatible with high performance cathodes. Furthermore, the drastic changes in volume that occur as silicon is lithiated and delithiated can lead to rapid cell failure and novel polymeric binders are known to help mitigate mechanical issues. We have recently developed a novel method to synthesize the conjugated polymer phenylmethylimine (polyPMI) using an imine metathesis reaction. We have demonstrated that this polymer can be used to stabilize silicon nanoparticles to produce a composite lithium-ion battery anode that is electrochemically stable for hundreds of lithiation and delithiation cycles with a Coulombic efficiency that is greater than 99.95% in a traditional carbonate liquid electrolyte. This work covers the structure and properties of polyPMI within the context of the unique mechanical and electrochemical requirements of nanoparticle silicon anodes. The electrochemical behavior of this polymer also offers new opportunities as an organic lithium-coordinating material that can be used to stabilize a variety of other battery electrodes. More broadly, we posit that this solution-processed, ionically conductive, and electronically conductive polymer is applicable for a variety of energy storage and conversion technologies. Finally, this work demonstrates how this novel polymer chemistry provides additional opportunities for tuning electrode architecture to target high energy full cells.

conjugated polymers↗

Resistive Switching of Spinel Li 4 Ti 5 O 12 Lithium-Ion Battery Material for Neuromorphic Computing

The rapid rise of AI has exposed significant limitations in conventional Von Neumann computing architecture, particularly in regard to speed and energy efficiency. To address these challenges, researchers are exploring a brain-inspired neuromorphic architecture that mimics biological neural networks, enabling massive parallel processing with reduced power consumption for complex AI computational demands. Recent interest has focused on utilizing battery electrodes and solid electrolyte materials for their resistive switching properties in developing a neuromorphic architecture. These properties are precisely tuned through local- and bulk-level chemical composition modifications via voltage bias stimuli. In this study, we demonstrate fabricating a three-terminal lithium-ion electrochemical transistor based on lithium titanium oxide (Li 4 Ti 5 O 12 ), a popular lithium-ion battery anode material. We deposited and characterized LTO thin films using RF sputtering, demonstrating a 6 orders of magnitude increase in electronic conductivity upon lithiation, with conductivity plateauing after 20% lithiation. Density functional theory calculations revealed transformation from the insulating to conducting state, supported by experimental characterization through X-Ray Photoelectron Spectroscopy (XPS) and Direct Current (DC) polarization analyses. The fabricated transistor consisted of LTO as the channel layer, gold as source/drain terminals, lithium phosphorus oxynitride (LiPON) as the lithium-ion conductor, and copper as the gate terminal. The device exhibited clear hysteresis in transfer characteristics due to lithium insertion/extraction processes. Long-term potentiation (LTP) and long-term depression (LTD) measurements showed an asymmetric ratio of 1.425 and maximum/minimum conductance ratio of 7.83. When implemented in a deep neural network (DNN) for MNIST handwritten digit recognition, the device achieved 92.03% accuracy over 20 training epochs. Detailed transport mechanism analysis revealed the crucial role of oxygen vacancies and interface effects in device operation. Our preliminary findings establish LTO-based lithium-ion electrochemical transistors as promising candidates for energy-efficient neuromorphic computing applications, offering potential solutions to traditional Von Neumann architecture limitations.

25 ENERGY STORAGE↗

Chloride Insertion Enhances the Electrochemical Oxidation of Iron Hydroxide Double-Layer Hydroxide into Oxyhydroxide in Alkaline Iron Batteries

Rechargeable alkaline iron batteries that constitute environmentally benign electrolytes and earth-abundant industrial materials are desirable green solutions for large-scale energy storage. As one of the most abundant metal elements in the earth’s crust, iron (Fe) can satisfy nearly all criteria for low-cost and safe battery electrodes. However, challenges in achieving reversible Fe redox impede their extensive implementation in modern energy supply systems. Here, this study revealed that Cl-anion insertion into Fe(OH) 2 layered double hydroxide (LDH) formed a green rust intermediate phase with the formula [Fe 2 2+ Fe 1 3+ (HO – ) 6 ] + [Cl] – , which assisted a high Fe(OH) 2 /FeOOH conversion reaction (64.7%) and improved cycling stability. This new iron redox chemistry was validated by operando X-ray diffraction, electrochemical testing, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) analysis, scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy (STEM-EDS) mapping, and molecular dynamics (MD) simulations. Our study provides new insight into designing LDH materials for high-capacity alkaline iron batteries.

36 MATERIALS SCIENCE↗

Stable lithium fluoride-based cathodes for metal and metal-ion batteries

A battery electrode composition is provided that comprises composite particles. Each composite particle may comprise, for example, active lithium fluoride/metal nanocomposite material optionally embedded into a nanoporous, electrically-conductive skeleton matrix material particle(s), where each of these composite particles is further encased in a Li-ion permeable, chemically and mechanically robust, protective outer shell that is impermeable to electrolyte solvent molecules. The active lithium fluoride/metal nanocomposite material is provided to store and release Li ions during battery operation.

25 ENERGY STORAGE↗