scholarly journals In Situ Lithiated ALD Niobium Oxide for Improved Long Term Cycling of LiCoO2 Cathodes: A Thin-Film Model Study

2021 ◽  
Author(s):  
Abdessalem Aribia ◽  
Jordi Sastre ◽  
Xubin Chen ◽  
Evgeniia Gilshtein ◽  
Ayodhya N. Tiwari ◽  
...  
Keyword(s):  
Thin Film ◽  
Niobium Oxide ◽  
Protective Coatings ◽  
Atomic Layer ◽  
Cycle Life ◽  
Interfacial Resistance ◽  
Film Model ◽  
Model Study ◽  
Cathode Degradation ◽  
Thin Film Model

Protective coatings applied to cathodes help to overcome interface stability issues and extend the cycle life of Li-ion batteries. However, it is difficult to isolate the effect of the coating because of the additives and non-ideal interfaces within 3D cathode composites. In this study we investigate niobium oxide (NbO<sub>x</sub>) as cathode coating in a thin-film model system, which allows assessing the cathode-coating-electrolyte interfaces. The conformal NbO<sub>x</sub> coating was applied by atomic layer deposition (ALD) onto thin-film LiCoO<sub>2</sub> cathodes. The cathode/coating stacks were annealed to lithiate and ensure sufficient ionic conductivity. A range of different coating thicknesses were investigated to improve the electrochemical cycling as compared to the uncoated cathodes. At a NbO<sub>x</sub> thickness of 30 nm, the cells retained 80% of the initial capacity after 493 cycles at 10 C, more than doubling the cycle life of the uncoated cathode. At the same thickness, a residual initial capacitance of 47% remained even at very high charge-discharge rates of 100 C. Using impedance spectroscopy measurements, we find that the enhanced performance is due to suppressed interfacial resistance growth during cycling. Elemental analysis using TOF-SIMS and XPS further revealed a bulk and surface contribution of the NbO<sub>x</sub> coating. These results show that lithiated ALD NbO<sub>x</sub> can significantly improve the performance of layered oxide cathodes by inhibiting the cathode degradation, resulting in prolonged cycle life.<br>

scholarly journals In situ lithiated ALD niobium oxide for improved long term cycling of layered oxide cathodes: A thin-film model study

2021 ◽  
Author(s):  
Abdessalem Aribia ◽  
Jordi Sastre ◽  
Xubin Chen ◽  
Evgeniia Gilshtein ◽  
Ayodhya N. Tiwari ◽  
...  
Keyword(s):  
Thin Film ◽  
Niobium Oxide ◽  
Cycle Life ◽  
Rate Performance ◽  
Film Model ◽  
Thin Film Model ◽  
Oxide Cathodes ◽  
Layered Oxide Cathodes ◽  
Initial Capacity

<p>Protective coatings applied to cathodes help to overcome interface stability issues and extend the cycle life of Li-ion batteries. However, within 3D cathode composites it is difficult to isolate the effect of the coating because of the additives and non-ideal interfaces. In this study we investigate niobium oxide (NbO<sub>x</sub>) as cathode coating in a thin-film model system, which provides simple access to the cathode-coating-electrolyte interface. The conformal NbO<sub>x</sub> coating was applied by atomic layer deposition (ALD) onto thin-film LiCoO<sub>2</sub> cathodes. The cathode/coating stacks were annealed to lithiate the NbO<sub>x</sub> and ensure sufficient ionic conductivity. A range of different coating thicknesses were investigated to improve the electrochemical cycling with respect to the uncoated cathode. At a NbO<sub>x</sub> thickness of 30 nm, the cells retained 80% of the initial capacity after 493 cycles at 10 C, more than doubling the cycle life of the uncoated cathode film. At the same thickness, the coating also showed a positive impact on the rate performance of the cathode: 47% of the initial capacity was accessible even at ultrahigh charge-discharge rates of 100 C. Using impedance spectroscopy measurements, we found that the enhanced performance is due to suppressed interfacial resistance growth during cycling. Elemental analysis using TOF-SIMS and XPS further revealed a bulk and surface contribution of the NbO<sub>x</sub> coating. These results show that in situ lithiated ALD NbO<sub>x</sub> can significantly improve the performance of layered oxide cathodes by enhancing interfacial charge transfer and inhibiting surface degradation of the cathode, resulting in better rate performance and cycle life.</p>

scholarly journals In situ lithiated ALD niobium oxide for improved long term cycling of layered oxide cathodes: A thin-film model study

2021 ◽  
Author(s):  
Abdessalem Aribia ◽  
Jordi Sastre ◽  
Xubin Chen ◽  
Evgeniia Gilshtein ◽  
Ayodhya N. Tiwari ◽  
...  
Keyword(s):  
Thin Film ◽  
Niobium Oxide ◽  
Cycle Life ◽  
Rate Performance ◽  
Film Model ◽  
Thin Film Model ◽  
Oxide Cathodes ◽  
Layered Oxide Cathodes ◽  
Initial Capacity

<p>Protective coatings applied to cathodes help to overcome interface stability issues and extend the cycle life of Li-ion batteries. However, within 3D cathode composites it is difficult to isolate the effect of the coating because of the additives and non-ideal interfaces. In this study we investigate niobium oxide (NbO<sub>x</sub>) as cathode coating in a thin-film model system, which provides simple access to the cathode-coating-electrolyte interface. The conformal NbO<sub>x</sub> coating was applied by atomic layer deposition (ALD) onto thin-film LiCoO<sub>2</sub> cathodes. The cathode/coating stacks were annealed to lithiate the NbO<sub>x</sub> and ensure sufficient ionic conductivity. A range of different coating thicknesses were investigated to improve the electrochemical cycling with respect to the uncoated cathode. At a NbO<sub>x</sub> thickness of 30 nm, the cells retained 80% of the initial capacity after 493 cycles at 10 C, more than doubling the cycle life of the uncoated cathode film. At the same thickness, the coating also showed a positive impact on the rate performance of the cathode: 47% of the initial capacity was accessible even at ultrahigh charge-discharge rates of 100 C. Using impedance spectroscopy measurements, we found that the enhanced performance is due to suppressed interfacial resistance growth during cycling. Elemental analysis using TOF-SIMS and XPS further revealed a bulk and surface contribution of the NbO<sub>x</sub> coating. These results show that in situ lithiated ALD NbO<sub>x</sub> can significantly improve the performance of layered oxide cathodes by enhancing interfacial charge transfer and inhibiting surface degradation of the cathode, resulting in better rate performance and cycle life.</p>

scholarly journals In Situ Lithiated ALD Niobium Oxide for Improved Long Term Cycling of Layered Oxide Cathodes:A Thin-Film Model Study

2021 ◽  
Author(s):  
Abdessalem Aribia ◽  
Jordi Sastre ◽  
Xubin Chen ◽  
Evgeniia Gilshtein ◽  
Moritz Futscher ◽  
...  
Keyword(s):  
Thin Film ◽  
Niobium Oxide ◽  
Layered Oxide ◽  
Film Model ◽  
Model Study ◽  
Thin Film Model

scholarly journals In situ Lithiated ALD Niobium Oxide for Improved Long Term Cycling of Layered Oxide Cathodes: A Thin-Film Model Study

2021 ◽  
Author(s):  
Abdessalem Aribia ◽  
Jordi Sastre ◽  
Xubin Chen ◽  
Evgeniia Gilshtein ◽  
Ayodhya N. Tiwari ◽  
...  
Keyword(s):  
Thin Film ◽  
Niobium Oxide ◽  
Cycle Life ◽  
Rate Performance ◽  
Film Model ◽  
Thin Film Model ◽  
Oxide Cathodes ◽  
Layered Oxide Cathodes ◽  
Initial Capacity

<p>Protective coatings applied to cathodes help to overcome interface stability issues and extend the cycle life of Li-ion batteries. However, within 3D cathode composites it is difficult to isolate the effect of the coating because of the additives and non-ideal interfaces. In this study we investigate niobium oxide (NbO<sub>x</sub>) as cathode coating in a thin-film model system, which provides simple access to the cathode-coating-electrolyte interface. The conformal NbO<sub>x</sub> coating was applied by atomic layer deposition (ALD) onto thin-film LiCoO<sub>2</sub> cathodes. The cathode/coating stacks were annealed to lithiate the NbO<sub>x</sub> and ensure sufficient ionic conductivity. A range of different coating thicknesses were investigated to improve the electrochemical cycling with respect to the uncoated cathode. At a NbO<sub>x</sub> thickness of 30 nm, the cells retained 80% of the initial capacity after 493 cycles at 10 C, more than doubling the cycle life of the uncoated cathode film. At the same thickness, the coating also showed a positive impact on the rate performance of the cathode: 47% of the initial capacity was accessible even at ultrahigh charge-discharge rates of 100 C. Using impedance spectroscopy measurements, we found that the enhanced performance is due to suppressed interfacial resistance growth during cycling. Elemental analysis using TOF-SIMS and XPS further revealed a bulk and surface contribution of the NbO<sub>x</sub> coating. These results show that in situ lithiated ALD NbO<sub>x</sub> can significantly improve the performance of layered oxide cathodes by enhancing interfacial charge transfer and inhibiting surface degradation of the cathode, resulting in better rate performance and cycle life.</p>

scholarly journals Two-layer modeling of thermally induced Bénard convection in thin liquid films: Volume of fluid approach vs thin-film model

AIP Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 045317
Author(s):  
Ali Mohammadtabar ◽  
Hadi Nazaripoor ◽  
Adham Riad ◽  
Arman Hemmati ◽  
Mohtada Sadrzadeh
Keyword(s):  
Thin Film ◽  
Volume Of Fluid ◽  
Liquid Films ◽  
Thin Liquid Films ◽  
Thermally Induced ◽  
Film Model ◽  
Bénard Convection ◽  
Thin Film Model ◽  
Benard Convection

scholarly journals Nanostructured, mesoporous Au/TiO2 model catalysts – structure, stability and catalytic properties

2011 ◽  
Vol 2 ◽  
pp. 593-606 ◽  
Author(s):  
Matthias Roos ◽  
Dominique Böcking ◽  
Kwabena Offeh Gyimah ◽  
Gabriela Kucerova ◽  
Joachim Bansmann ◽  
...  
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Model Catalysts ◽  
Model Systems ◽  
Structure Stability ◽  
Titanium Tetraisopropoxide ◽  
X Ray ◽  
Film Model ◽  
Thin Film Model

Aiming at model systems with close-to-realistic transport properties, we have prepared and studied planar Au/TiO2 thin-film model catalysts consisting of a thin mesoporous TiO2 film of 200–400 nm thickness with Au nanoparticles, with a mean particle size of ~2 nm diameter, homogeneously distributed therein. The systems were prepared by spin-coating of a mesoporous TiO2 film from solutions of ethanolic titanium tetraisopropoxide and Pluronic P123 on planar Si(100) substrates, calcination at 350 °C and subsequent Au loading by a deposition–precipitation procedure, followed by a final calcination step for catalyst activation. The structural and chemical properties of these model systems were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption, inductively coupled plasma ionization spectroscopy (ICP–OES) and X-ray photoelectron spectroscopy (XPS). The catalytic properties were evaluated through the oxidation of CO as a test reaction, and reactivities were measured directly above the film with a scanning mass spectrometer. We can demonstrate that the thin-film model catalysts closely resemble dispersed Au/TiO2 supported catalysts in their characteristic structural and catalytic properties, and hence can be considered as suitable for catalytic model studies. The linear increase of the catalytic activity with film thickness indicates that transport limitations inside the Au/TiO2 film catalyst are negligible, i.e., below the detection limit.

Detrimental MnPO4F and MnF2 formation on LiMn2O4 in the 3 V region

2021 ◽  
Author(s):  
Louis L. De Taeye ◽  
Philippe M. Vereecken
Keyword(s):  
Thin Film ◽  
Direct Interaction ◽  
Film Model ◽  
Thin Film Model ◽  
V Region

The 3 V region of LMO is inhibited when using LiPF6 based electrolytes, due to the formation of a LiF/MnF2 decomposition layer. This layer is formed by direct interaction between LiPF6 and Li2Mn2O4, as demonstrated using a thin-film model electrode.

Modelling of Partially Wetting Liquid Film Using an Enhanced Thin Film Model for Aero-Engine Bearing Chamber Applications

2020 ◽  
Author(s):  
K. Singh ◽  
M. Sharabi ◽  
R. Jefferson-Loveday ◽  
S. Ambrose ◽  
C. Eastwick ◽  
...  
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Film Thickness ◽  
Liquid Film ◽  
Flow Rate ◽  
Operating Conditions ◽  
Film Model ◽  
Thin Film Model ◽  
Wide Range ◽  
Aero Engine

Abstract In the case of aero-engine, thin lubricating film servers dual purpose of lubrication and cooling. Prediction of dry patches or lubricant starved region in bearing or bearing chambers are required for safe operation of these components. In the present work thin liquid film flow is numerically investigated using the framework of the Eulerian thin film model (ETFM) for conditions which exhibit partial wetting phenomenon. This model includes a parameter that requires adjustment to account for the dynamic contact angle. Two different experimental data sets have been used for comparisons against simulations, which cover a wide range of operating conditions including varying the flow rate, inclination angle, contact angle, and liquid-gas surface tension coefficient. A new expression for the model parameter has been proposed and calibrated based on the simulated cases. This is employed to predict film thickness on a bearing chamber which is subjected to a complex multiphase flow. From this study, it is observed that the proposed approach shows good quantitative comparisons of the film thickness of flow down an inclined plate and for the representative bearing chamber. A comparison of model predictions with and without wetting and drying capabilities is also presented on the bearing chamber for shaft speed in the range of 2,500 RPM to 10,000 RPM and flow rate in the range of 0.5 liter per minute (LPM) to 2.5 LPM.

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