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Electrode Blocking Due to Redox Reactions in Aluminum Chloride-Sodium Iodide Molten Salts

Journal of the Electrochemical Society

Maraschky, Adam M.; Percival, Stephen P.; Lee, Rose Y.; Laros, James H.; Peretti, Amanda S.; Spoerke, Erik D.; Small, Leo J.

Iodide redox reactions in molten NaI/AlCl3 are shown to generate surface-blocking films, which may limit the useful cycling rates and energy densities of molten sodium batteries below 150 °C. An experimental investigation of electrode interfacial stability at 110 °C reveals the source of the reaction rate limitations. Electrochemical experiments in a 3-electrode configuration confirm an increase of resistance on the electrode surface after oxidation or reduction current is passed. Using chronopotentiometry, chronoamperometry, cyclic voltammetry, and electrochemical impedance spectroscopy, the film formation is shown to depend on the electrode material (W, Mo, Ta, or glassy carbon), as well as the Lewis acidity and molar ratio of I−/I3− in the molten salt electrolytes. These factors impact the amount of charge that can be passed at a given current density prior to developing excessive overpotential due to film formation that blocks the electrode surface. The results presented here guide the design and use of iodide-based molten salt electrolytes and electrode materials for grid scale battery applications.

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TYPE Journal Article YEAR 2023
DOIOSTIDOIScopusOSTIScopus

Compaction of crushed salt for the safe containment – Overview of Phase 2 of the KOMPASS project

Friedenberg, Larissa; Czaikowski, Oliver; Lerch, Christian; Muller Hoeppe, Nina; Rahmig, Michael; Bartol, Jeroen; Dusterloh, Uwe; Lerche, Svetlana; Saruulbayar, Nachinzorig; Lippmann-Pipke, Johanna; Laurich, Ben; Svensson, Kristoff; Zemke, Kornelia; Thiedau, Jan; Liu, Wenting; Gartzke, Anne; Popp, Till; Ludeling, Christoph; Rolke, C.; Rabbel, Ole; Reedlunn, Benjamin R.; Laros, James H.; Mills, Melissa M.; Coulibaly, Jibril B.; Spiers, Chris; De Bresser, Hans; Hangx, Suzanne; Van Oosterhout, Bart

Abstract not provided.

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TYPE Conference Proceeding YEAR 2023
DOIOSTI

Dynamic high pressure phase transformation of ZrW2O8

AIP Advances

Bishop, Sean R.; Lowry, Daniel R.; Peretti, Amanda S.; Laros, James H.; Knudson, Marcus D.; Sarracino, Alex; Mahaffey, Jacob T.; Murray, Shannon E.

Phase transformations under high strain rates (dynamic compression) are examined in situ on ZrW2O8, a negative thermal expansion ternary ceramic displaying polymorphism. Amorphization, consistent with prior quasi-static measurements, was observed at a peak pressure of 3.0 GPa under dynamic conditions, which approximate those expected during fabrication. Evidence of partial amorphization was observed at lower pressure (1.8 GPa) that may be kinetically restrained by the short (<∼150 ns) time scale of the applied high pressure. The impact of kinetics of pressure-induced amorphization from material fabrication methods is briefly discussed.

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TYPE Journal Article YEAR 2023
DOIOSTIScopusDOIOSTIScopus

Parallel Matrix Multiplication Using Voltage-Controlled Magnetic Anisotropy Domain Wall Logic

IEEE Journal on Exploratory Solid-State Computational Devices and Circuits

Zogbi, Nicholas; Liu, Samuel; Bennett, Christopher H.; Agarwal, Sapan A.; Marinella, Matthew J.; Incorvia, Jean A.C.; Xiao, Tianyao X.

The domain wall-magnetic tunnel junction (DW-MTJ) is a versatile device that can simultaneously store data and perform computations. These three-terminal devices are promising for digital logic due to their nonvolatility, low-energy operation, and radiation hardness. Here, we augment the DW-MTJ logic gate with voltage-controlled magnetic anisotropy (VCMA) to improve the reliability of logical concatenation in the presence of realistic process variations. VCMA creates potential wells that allow for reliable and repeatable localization of domain walls (DWs). The DW-MTJ logic gate supports different fanouts, allowing for multiple inputs and outputs for a single device without affecting the area. We simulate a systolic array of DW-MTJ multiply-accumulate (MAC) units with 4-bit and 8-bit precision, which uses the nonvolatility of DW-MTJ logic gates to enable fine-grained pipelining and high parallelism. The DW-MTJ systolic array provides comparable throughput and efficiency to state-of-the-art CMOS systolic arrays while being radiation-hard. These results improve the feasibility of using DW-based processors, especially for extreme-environment applications such as space.

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TYPE Journal Article YEAR 2023
DOIOSTIScopusDOIOSTIScopus

Post-detonation fireball modeling: Validation of freeze out approximations

Physics of Fluids

Egeln, Anthony A.; Hewson, John C.; Guildenbecher, Daniel R.; Marinis, Ryan T.; Welliver, Marc W.; Houim, Ryan W.

A numerical simulation study was performed to examine the post-detonation reaction processes produced by the detonation of a 12 mm diameter hemispherical pentaerythritol tetranitrate (PETN) explosive charge. The simulations used a finite rate detailed chemical reaction model consisting of 59 species and 368 reactions to capture post-detonation reaction processes including air dissociation from Mach 19+ shock waves that initially break out of the PETN charge, reactions within the detonation products during expansion, and afterburning when the detonation products mix with the shock heated air. The multi-species and thermodynamically complete Becker-Kistiakowsky-Wilson real-gas equation of state is used for the gaseous phase to allow for the mixing of reactive species. A recent simplified reactive burn model is used to propagate the detonation through the charge and allow for detailed post-detonation reaction processes. The computed blast, shock structures, and mole fractions of species within the detonation products agree well with experimental measurements. A comparison of the simulation results to equilibrium calculations indicates that the assumption of a local equilibrium is fairly accurate until the detonation products rapidly cool to temperatures in the range of 1500-1900 K by expansion waves. Below this range, the computed results show mole fractions that are nearly chemically frozen within the detonation products for a significant portion of expansion. These results are consistent with the freeze out approximation used in the blast modeling community.

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TYPE Journal Article YEAR 2023
DOIOSTIScopus

Negligible magnetic losses at low temperatures in liquid phase epitaxy grown Y3Fe5O12 films

Physical Review Materials

Will-Cole, A.R.; Hart, James L.; Lauter, Valeria; Grutter, Alexander; Dubs, Carsten; Lindner, Morris; Reimann, Timmy; Pearce, Charles J.; Monson, Todd M.; Cha, Judy J.; Heiman, Don; Sun, Nian X.

Yttrium iron garnet (Y3Fe5O12; YIG) has a unique combination of low magnetic damping, high spin-wave conductivity, and insulating properties that make it a highly attractive material for a variety of applications in the fields of magnetics and spintronics. While the room-temperature magnetization dynamics of YIG have been extensively studied, there are limited reports correlating the low-temperature magnetization dynamics to the material structure or growth method. Here, in this study, we investigate liquid phase epitaxy grown YIG films and their magnetization dynamics at temperatures down to 10 K. We show there is a negligible increase in the ferromagnetic resonance linewidth down to 10 K, which is unique when compared with YIG films grown by other deposition methods. From the broadband ferromagnetic resonance measurements, polarized neutron reflectivity, and scanning transmission electron microscopy, we conclude that these liquid phase epitaxy grown films have negligible rare-earth impurities present, specifically the suppression of Gd diffusion from the Gd3Ga5O12 (GGG) substrate into the Y3Fe5O12 film, and therefore negligible magnetic losses attributed to the slow-relaxation mechanism. Overall, liquid phase epitaxy YIG films have a YIG/GGG interface that is five times sharper and have ten times lower ferromagnetic resonance linewidths below 50 K than comparable YIG films by other deposition methods. Thus, liquid phase epitaxy grown YIG films are ideal for low-temperature experiments/applications that require low magnetic losses, such as quantum transduction and manipulation via magnon coupling.

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TYPE Journal Article YEAR 2023
DOIOSTIDOIOSTI

Influence of surface adsorption on MoS2 memtransistor switching kinetics

Applied Physics Letters

Cain, John M.; Chou, Stanley S.; Lu, Tzu-Ming L.; Yan, Xiaodong; Liu, Stephanie E.; Qian, Justin H.; Zeng, Thomas T.; Sangwan, Vinod K.; Hersam, Mark C.

Sulfur-deficient polycrystalline two-dimensional (2D) molybdenum disulfide (MoS2) memtransistors exhibit gate-tunable memristive switching to implement emerging memory operations and neuromorphic computing paradigms. Grain boundaries and sulfur vacancies are critical for memristive switching; however, the underlying physical mechanisms are not fully understood. Furthermore, the adsorption of water and gaseous species strongly perturbs electronic transport in monolayer MoS2, and little work has been done to explore the influence of surface interactions on defect-related kinetics that produces memristive switching. Here, we study the switching kinetics of back-gated MoS2 memtransistors using current transient measurements in a controlled atmosphere chamber. We observe that adsorbed water molecules lead to suppression of the electronic trap-filling processes concomitant with the resistive switching process, resulting in altered kinetics of the resistive switching. Additionally, using the transient response from “bunched” drain voltage pulse trains performed as a function of temperature, we extract the energy of the affected trap state and find that it places the trap roughly midgap [ E T = E C - 0.7 ( ± 0.4 ) eV]. Our results highlight the importance of controlling for surface interactions that may affect switching kinetics in 2D memtransistors, synaptic transistors, and related memory devices.

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TYPE Journal Article YEAR 2023
DOIOSTIScopus
Results 1301–1400 of 96,771
Results 1301–1400 of 96,771