In this paper, the characteristics of effervescent atomization are studied experimentally. A high speed camera was used to record the bubbling process and the change of the flow regime in the mixing chamber. Three typ...
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Poor rate performance limits the application of high-areal-loading electrodes in energy storage, and optimizing the microstructure of the cathode is considered as a way to improve this limitation. In this study, we in...
Poor rate performance limits the application of high-areal-loading electrodes in energy storage, and optimizing the microstructure of the cathode is considered as a way to improve this limitation. In this study, we integrated X-ray computed tomography (XCT) with digital technology (virtual electrodes and microstructure-based numerical simulations) to quantify the correlation between electrode structure and internal kinetic performance of lithium-ion electrodes. Results show that electrode structure alters the internal kinetic properties, thereby affecting rate capacity and nominal potential. Based on the parametric relationship between electrode structure and electrochemical-thermal properties, we explored the effects of structural regulation on electrode performance. Vertical channels significantly enhanced the rate capability and ohmic heating rate of small-particle electrodes, while solid-phase diffusion (SPD) dominated the discharge performance of large-particle electrodes, exhibiting low sensitivity to tortuous strategies. Furthermore, electrodes with abundant SPD barriers exhibit unidirectional propagation of reaction fronts, resulting in a deeper SPD-limited region. This observation inspired the integration of two structural strategies that favor both mass transport and reaction penetration. Optimized electrode structures enhanced energy density at high rates and accommodated diverse particle sizes and thicknesses. Additionally, the coupling effect of the heat transfer environment on electrode performance was investigated. This study presents a novel paradigm for bottom-up electrode design using microstructure-resolved model, providing both microscopic mechanisms and quantitative insights for advanced battery development.
Efficient non-noble-metal catalysts are essential for the industrial application of ammonia decomposition reaction (ADR). This work reports a Ni-Co bimetallic thermocatalyst supported by BaCeYO (BCY), a proton-conduct...
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Efficient non-noble-metal catalysts are essential for the industrial application of ammonia decomposition reaction (ADR). This work reports a Ni-Co bimetallic thermocatalyst supported by BaCeYO (BCY), a proton-conducting cermet, demonstrating state-of-the-art ADR performance. This catalyst achieves 100% NH conversion at 550 °C with a gas hourly space velocity of 9000 mL h g and 95.1% conversion at 520 °C, notably lowering ADR temperature requirements. It also demonstrates outstanding stability under diverse conditions. The superior ADR activity arises from Ni-Co synergies, Ce's strong basicity, as well as extensive hydrogen spillover facilitated by Y doping-induced high oxygen vacancies. Specifically, BCY's strong adsorption of H* promotes the migration of H* from the active Ni/Co surface to oxygen sites of the support and subsequent rapid diffusion as OH* in oxygen vacancy channels. This metal-support-interaction-induced hydrogen spillover effect further liberates the original active sites and boosts ammonia activation.
The thermal safety accidents of high specific energy lithium-ion batteries (LIBs) occur frequently, impeding their further large-scale application in electric vehicles. In this study, the experimental systems for semi...
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The thermal safety accidents of high specific energy lithium-ion batteries (LIBs) occur frequently, impeding their further large-scale application in electric vehicles. In this study, the experimental systems for semi-open and sealed spaces are established. Meanwhile, based on the liquid immersion cooling (LIC) system, the thermal runaway (TR) suppression mechanisms of the single LIB and LIB pack are reported systematically. For the single LIB (two pouch cells connected in series), the LIB is penetrated to 50 % depth, namely, the first pouch cell. We discover that the unpenetrated pouch cell remains at 0.58 V and is structurally intact. Compared with the natural convection conditions, the LIB peak temperature is decreased by 141.3 °C. The gas generation reactions are significantly mitigated. Furthermore, the heat and gas generation are gradually decreased with a reduction in state of charge (SOC). More importantly, after penetrating the first LIB in the LIB pack, we observe that the maximum temperature of the neighboring LIB is around 49 °C. The study provides a first step towards LIB thermal safety protection projects.
The erosion-corrosion behavior poses a significant threat to marine equipment, driven by complex multi-physics processes such as sand movement, surface erosion, electrochemical reactions, and corrosive ion transport. ...
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The erosion-corrosion behavior poses a significant threat to marine equipment, driven by complex multi-physics processes such as sand movement, surface erosion, electrochemical reactions, and corrosive ion transport. Aiming at the widely used rotating liquid-solid two-phase flow system in a marine environment, this study investigates the role of flow velocity in the erosion-corrosion behavior of Ni 2 FeCrMo 0.2 alloy. The coupling analysis of multi-component weight loss, electrochemical kinetics, and microstructure characterization clarifies the interactions between fluid flow, sand migration, ion transfer, and damage morphology, revealing the synergistic erosion-corrosion mechanism. The results show that the erosion-corrosion mechanism transfers with flow velocity. At low velocities, the erosion effect on the harder metal matrix is weak due to insufficient kinetic energy of the sand particles. However, the sand-surface impingement on the softer corrosion products and the mass transfer of corrosive ions lead to erosion-enhanced corrosion, which dominates the material damage process. In contrast, at higher velocities, the impact kinetic energy and frequency of sand particles rise, causing the erosion rate to increase exponentially, which surpasses corrosion, making erosion as the dominant damage mechanism at high velocities. These results highlight the critical role of flow velocity in controlling the erosion-corrosion synergy behavior.
In this study the effect of thermal spray process on wear resistance of NiAl/Cr2C3 thermal spray coating has been investigated. For this purpose the NiAl power mixed with 10 %wt. Cr2C3 powder and milled for 1 hrs at a...
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