scholarly journals Atomic layer deposited V2O5 coatings: a promising cathode for Li-ion batteries

2019 ◽  
Vol 10 (1) ◽  
pp. 21-28
Author(s):  
Martyn Pemble ◽  
Ian Povey ◽  
Dimitra Vernardou

A modified, thermal atomic layer deposition process was employed for the pulsed chemical vapor deposition growth of vanadium pentoxide films using tetrakis (dimethylamino) vanadium and water as a co-reagent.Depositions were carried out at 350oC for 400 pulsed CVD cycles, and samples were subsequently annealed for 1hour at 400°C in air to form materials with enhanced cycling stability during the continuous lithium-ion intercala­tion/deintercalation processes. The diffusion coefficient was estimated to be 2.04x10-10 and 4.10x10-10 cm2 s-1 for the cathodic and anodic processes, respectively. These values are comparable or lower than those reported in the literature, indicating the capability of Li+ of getting access into the vanadium pentoxide framework at a fast rate. Overall, it presents a specific discharge capacity of 280 mAh g-1, capacity retention of 75 % after 10000 scans, a coulombic efficiency of 100 % for the first scan, dropping to 85 % for the 10000th scan, and specific energy of 523 Wh g-1.

Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
César Masse de la Huerta ◽  
Viet Nguyen ◽  
Jean-Marc Dedulle ◽  
Daniel Bellet ◽  
Carmen Jiménez ◽  
...  

Within the materials deposition techniques, Spatial Atomic Layer Deposition (SALD) is gaining momentum since it is a high throughput and low-cost alternative to conventional atomic layer deposition (ALD). SALD relies on a physical separation (rather than temporal separation, as is the case in conventional ALD) of gas-diluted reactants over the surface of the substrate by a region containing an inert gas. Thus, fluid dynamics play a role in SALD since precursor intermixing must be avoided in order to have surface-limited reactions leading to ALD growth, as opposed to chemical vapor deposition growth (CVD). Fluid dynamics in SALD mainly depends on the geometry of the reactor and its components. To quantify and understand the parameters that may influence the deposition of films in SALD, the present contribution describes a Computational Fluid Dynamics simulation that was coupled, using Comsol Multiphysics®, with concentration diffusion and temperature-based surface chemical reactions to evaluate how different parameters influence precursor spatial separation. In particular, we have used the simulation of a close-proximity SALD reactor based on an injector manifold head. We show the effect of certain parameters in our system on the efficiency of the gas separation. Our results show that the injector head-substrate distance (also called deposition gap) needs to be carefully adjusted to prevent precursor intermixing and thus CVD growth. We also demonstrate that hindered flow due to a non-efficient evacuation of the flows through the head leads to precursor intermixing. Finally, we show that precursor intermixing can be used to perform area-selective deposition.


ACS Nano ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. 464-473 ◽  
Author(s):  
Keith E. Gregorczyk ◽  
Alexander C. Kozen ◽  
Xinyi Chen ◽  
Marshall A. Schroeder ◽  
Malachi Noked ◽  
...  

2018 ◽  
Vol 25 (2) ◽  
pp. 511-516
Author(s):  
Dimitry Kouzminov ◽  
James Cournoyer ◽  
Somchintana Norasetthekul ◽  
Harish Muthuraman ◽  
Qi Gao

AbstractApplication of atom probe tomography (APT) and 1.5D secondary ion mass spectrometry (SIMS) as complimentary techniques to study fin sidewall doping by plasma implantation (PLAD) is the focus of this paper. Unlike planar transistors, characterization of 3D devices both by SIMS and APT requires sample preparation via trench backfill with α-Si, or other material, via chemical vapor deposition or atomic layer deposition process due to high aspect ratio of test structures. Certain artifacts with adverse impacts on quantitative results encountered in this study are discussed.


MRS Advances ◽  
2017 ◽  
Vol 2 (28) ◽  
pp. 1499-1503 ◽  
Author(s):  
Ken Bosnick ◽  
Pouyan Motamedi ◽  
Tim Patrie ◽  
Kenneth Cadien

ABSTRACTCatalytic chemical vapor deposition enables the synthesis and deposition of carbon nanotubes (CNT) directly on substrates, thereby immobilizing them and potentially preventing them from bundling after synthesis. In this work, we investigate the use of this strategy to prepare ceramic hybrids with unbundled CNTs on aluminum oxide (AO) powder and fabric substrates, which are commonly used in the fabrication of ceramic laminate composites. CNT –AO powder hybrids are produced in 250 g batches with up to about 3 wt% CNT content, which is a sufficient amount for sintering into composite plates for mechanical and ballistic characterization. CNT – AO fabric hybrids are produced and it is found that the polymer coating that comes on the as-purchased fabric aids with CNT deposition. Conformal nickel and nickel oxide films deposited by an atomic layer deposition process are found to be excellent catalysts for CNT deposition. These conformal metal films are being used to create better CNT – ceramic hybrids for processing into better composite materials.


2017 ◽  
Vol 5 (19) ◽  
pp. 8916-8921 ◽  
Author(s):  
Zhujun Yao ◽  
Xinhui Xia ◽  
Yu Zhong ◽  
Yadong Wang ◽  
Bowei Zhang ◽  
...  

In the present study, we report a synthetic strategy for the direct fabrication of hybrid vertical graphene/lithium titanate–CNTs arrays via atomic layer deposition in combination with chemical vapor deposition.


2015 ◽  
Vol 8 (7) ◽  
pp. 1889-1904 ◽  
Author(s):  
Xinran Wang ◽  
Gleb Yushin

Recent developments and applications of atomic layer deposition and chemical vapor deposition in energy storage devices are reviewed.


2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 907
Author(s):  
Yury Koshtyal ◽  
Ilya Mitrofanov ◽  
Denis Nazarov ◽  
Oleg Medvedev ◽  
Artem Kim ◽  
...  

Nanostructured metal oxides (MOs) demonstrate good electrochemical properties and are regarded as promising anode materials for high-performance lithium-ion batteries (LIBs). The capacity of nickel-cobalt oxides-based materials is among the highest for binary transition metals oxide (TMOs). In the present paper, we report the investigation of Ni-Co-O (NCO) thin films obtained by atomic layer deposition (ALD) using nickel and cobalt metallocenes in a combination with oxygen plasma. The formation of NCO films with different ratios of Ni and Co was provided by ALD cycles leading to the formation of nickel oxide (a) and cobalt oxide (b) in one supercycle (linear combination of a and b cycles). The film thickness was set by the number of supercycles. The synthesized films had a uniform chemical composition over the depth with an admixture of metallic nickel and carbon up to 4 at.%. All samples were characterized by a single NixCo1-xO phase with a cubic face-centered lattice and a uniform density. The surface of the NCO films was uniform, with rare inclusions of nanoparticles 15–30 nm in diameter. The growth rates of all films on steel were higher than those on silicon substrates, and this difference increased with increasing cobalt concentration in the films. In this paper, we propose a method for processing cyclic voltammetry curves for revealing the influence of individual components (nickel oxide, cobalt oxide and solid electrolyte interface—SEI) on the electrochemical capacity. The initial capacity of NCO films was augmented with an increase of nickel oxide content.


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