bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Passivity and Pitting Corrosion Behavior of Additive Manufactured 17-4PH Stainless Steel
Authors: Barroux Adrien , Ducommun Nadège , Nivet Eric , Delgado Julien , Laffont Lydia , Blanc Christine 
Published: December 2020

Conventionaly manufactured, i.e. wrought, 17-4PH martensitic stainless steel (MSS) is widely used in a large variety of applications, going from biomedical ustensils to large turbine blades. Recently, it appeared as a good candidate for additive manufacturing processes, e.g. laser beam melting (LBM), which is certainly the most common and developed process at this time. The specific microstructures generated by LBM have been well discussed in the literature for many types of materials. Nevertheless, these peculiarities can also affect the durability of the LBM-manufactured parts and specifically their corrosion behavior.
The main goal of this work was to propose a detailed study of the pitting corrosion behavior of a 17-4PH MSS manufactured by LBM. In this framework, LBM parts were built from 17-4PH MSS powder, using optimized machine parameters. Samples of a commercial counterpart (CM –MSS) machined from a wrought cylindrical bar were studied as references. The pitting corrosion behavior of both MSSs was studied in chloride-containing solutions by combining linear potentiokinetic polarization associated with the determination of pitting potentials, and a statistical analysis of the current transients observed during potentiostatic experiments for metastable pitting. Significant differences were observed between the LBM and CM MSSs. They were explained considering the passive film composition, structure and morphology evaluated by combining transmission electron microscopy (TEM), scanning TEM (STEM) using the high-angle annular dark field (HAADF) mode, and Energy dispersive X-ray Spectroscopy (EDS) analyses. Results were related to the specific microstructure of the LBM samples as compared to that of the CM MSS, both microstructures being characterized by TEM, STEM and EDS.
(Invited) Quantifying Outgassing, Surface Oxygen Depletion and Solid Carbonate Evolution to Understand Interfacial Reactivity in Cathode Active Materials
Authors: McCloskey Bryan D. , Ramakrishnan Srinivasan , Renfrew Sara E 
Published: December 2020

Complex degradation processes at the cathode-electrolyte interface limit the high voltage application of conventional and emerging cathode materials (e.g., Li or Ni-rich LiMO2, M= Li, Ni, Mn, Co, (NMC) layered oxides and Li-excess disordered rocksalt materials). We will present results in which quantitative gas evolution and acid titrations are used to identify key contributions to these high voltage instabilities in Ni-rich and Li-rich NMC materials, including electrolyte degradation evolution and the impact that residual solid carbonate has on parasitic reactions.1-2 This presentation will emphasize the need to accurately quantify these minor side reactions to fully understand their large influence on battery performance. We show that by using a short aqueous rinse on NMC powders prior to their integration into porous electrodes, adventitious carbonates are removed from the material surface, which also undergoes a structural change. Both of these effects dramatically reduce parasitic gas evolution from the materials and, in certain cases, improve the active material’s long term cyclability without compromising its capacity.3-4

References
1. Renfrew, S. E.; McCloskey, B. D. Quantification of surface oxygen depletion and solid carbonate evolution on the first cycle of LiNi0.6Mn0.2Co0.2O2 electrodes. ACS Applied Energy Materials 2019, 2, 3762-3772. 10.1021/acsaem.9b00459
2. Renfrew, S. E.; McCloskey, B. D. Residual lithium carbonate predominantly accounts for first cycle CO2 and CO outgassing of Li-stoichiometric and Li-rich layered transition-metal oxides. Journal of the American Chemical Society 2017, 139, 17853-17860. 10.1021/jacs.7b08461
3. Renfrew, S. E.; Kaufman, L. A.; McCloskey, B. D. Altering surface contaminants and defects influences the first-cycle outgassing and irreversible transformations of LiNi0.6Mn0.2Co0.2O2. ACS Applied Materials & Interfaces 2019, 11, 34913-34921. 10.1021/acsami.9b09992
4. Ramakrishnan, S.; Park, B.; Wu, J.; Yang, W.; McCloskey, B. D. Extended interfacial stability through simple acid rinsing in a Li-rich oxide cathode material. Journal of the American Chemical Society 2020, 142, 8522-8531. 10.1021/jacs.0c02859
(Invited) Atmospheric Corrosion of Magnesium Alloys: Influence of Aluminium Content
Authors: Thierry Dominique , Persson Dan 
Published: December 2020

Magnesium has gained considerable interest as a structural material for automotive and aerospace applications due to its low density and high specific strength. The use of magnesium alloys in engineering applications is, however, mainly limited by their unsatisfactory surface properties and their poor corrosion resistance. In recent years, significant improvements have been made in achieving a better corrosion resistance particularly by reducing the contents of impurities such as Fe, Cu, and Ni. Intermetallic phases, a result of the casting process, play an important role in the corrosion process. The role of these intermetallic phases has been addressed in a number of papers [1–3]. The role of aluminum in the atmospheric corrosion of magnesium alloys has less addressed in the literature [4]. Esmaily et al have shown recently that the rate of corrosion of magnesium alloys decreased when increasing the Al content. However these experiments were performed on commercial magnesium alloys produced high pressure die casting under constant RH exposure at 90% RH.
In our work the corrosion behavior of binary Mg-Al alloys as well as that of commercial magnesium alloys with different aluminum contents have studied both under cyclic corrosion exposure in the laboratory and in field exposures in France and in Vietnam. Analyses of corrosion products have also been conducted. Additional in-situ measurements have been performed in order to better understand the atmospheric corrosion mechanisms of Mg alloys.
An important decrease in the maximum pit depth can be observed after different laboratory exposures when increasing the aluminum content in the material. Similar results have been obtained after 9 months exposure in Field. Hence, from these results it is obvious that an increase of the aluminum concentration in Mg-Al alloys decreased the corrosion rate of the alloy. This lead in lower mass loss and less deep corrosion attacks in the magnesium grains. The analyses of corrosion products formed after the cyclic corrosion tests and field exposures revealed the presence of Magnesium carbonate and MgCO3(OH)4,4H20, respectively. In both cases magnesium hydroxide (Mg(OH)2 was also found in the corrosion products. The results will be discussed in relation with the microstructure of the cast materials.

O. Lunder, J.E. Lein, S.M. Hesjevik, T.K. Aune, K. Nisancioglu, Werkstoffe und Korrosion 45 (6)

(1994) 331–340.

O. Lunder, J.H. Nordlien, K. Nisangliou, Corrosion Reviews 15 (3–4) (1997) 439–469.

G. Song, A. Atrens, M. Dargusch, Corrosion Science 41 (1999) 249–273.

M. Esmailly, D.B. Blucher, J.E. Svensson, M. Halvarson and LG Johansson, Scripta Materiala, 115 (2016), 91-96
Smart Coatings for Corrosion Protection: On the Need for New Coating Concepts
Authors: Rohwerder Michael 
Published: December 2020

Ideally smart coatings for corrosion protection have to be able to protect the underlying metal from corrosion by providing excellent barrier properties, at the same time showing a fast and efficient self-healing in case a defect down to the metal is inflicted into them, while being as delamination resistant as possible.
These seem to be basically incompatible properties, as either mobility of species is high or the coating is highly impermeable, i.e. it is difficult to envisage a coating that can be both at the same time. In fact, in recent works we have shown that for excellent self-healing performance especially the resistance against cathodic delamination of a coating should be significantly weakened [1, 2]. Using conductive polymer additions to non-conductive coatings, both high self-healing activity [1-3] as well as high resistance against cathodic delamination [4, 5] can be controlled in a wide range.
Based on an in-depth understanding of the underlying mechanisms we are currently working on strategies for developing coatings that show excellent active as well as passive protection properties. Latest progress of the research on this topic well be presented and the implication will be discussed.
[1] M. Uebel, L. Exbrayat, M. rabe, T.H. Tran, D. Crespy, M. Rohwerder, On the Role of Trigger Signal Spreading Velocity for Efficient Self-Healing Coatings for Corrosion Protection, Electrochem. Soc. 165 (2018) C1017-C1027
[2] H. Tran , A. Vimalanandan , G.Genchev , J. Fickert , K. Landfester, D. Crespy , M.Rohwerder, Regenerative Nano-Hybrid Coating Tailored for Autonomous Corrosion Protection, Advanced Materials 27(25) (2015) 3825-3830
[3] A. Vimalanandan, L.P. Lv, T.H. Tran, K. Landfester, D. Crespy, M. Rohwerder, Redox-Responsive Self-Healing for Corrosion Protection, Advanced Materials 25(48) (2013) 6980-6984
[4] Anna Merz, Matthias Uebel, Michael Rohwerder, The Protection Zone: A Long-Range Corrosion Protection Mechanism around Conducting Polymer Particles in Composite Coatings: Part I. Polyaniline and Polypyrrole, Electrochem. Soc. 166 (2019) C304-C313
[5] Anna Merz, Michael Rohwerder, The Protection Zone: A Long-Range Corrosion Protection Mechanism around Conducting Polymer Particles in Composite Coatings: Part II. PEDOT:PSS, Electrochem. Soc. 166 (2019) C314-C320
Cathodic Corrosion Protection of Steel with Electroplated Aluminum Alloys
Authors: Bottcher Rene , Ispas Adriana , Bund Andreas 
Published: December 2020

Aluminum has excellent corrosion properties due to the formation of a dense oxide layer. This layer spontaneously forms in contact with air and protects the bulk material from further oxidation. Unfortunately, the formation of the natural oxide layer renders pure aluminum passive so that it is not a good candidate for the corrosion protection of a more noble substrate like steel. Therefore, for applications as a corrosion protection layer aluminum should be alloyed with other elements to prevent complete passivation.
Electrodeposition is an elegant and cost-efficient method to apply thin coatings on various substrates with complex geometries. The layer properties can be easily controlled by adjusting the deposition parameters (current density, temperature, electrolyte composition). Aluminum cannot be deposited from aqueous electrolytes because of its negative Nernst potential (-1.66 V vs. NHE). Ionic liquids (ILs) are suitable electrolytes for the deposition of reactive metals, such as Al, Nb and Ta. They have a broad electrochemical window (> 3 V) and high electrical conductivity, and show good solubility for many metal salts.
This paper will discuss the deposition of binary aluminum alloys from imidazolium-based ILs and their corrosion behaviour. Results from potentiodynamic polarization experiments will be compared with results from salt spray tests and long-term environmental exposure experiments (> 1 year) to assess the suitability of the alloys for cathodic corrosion protection of steel.
(Invited) The Life and Death of Anode-Free Lithium Metal Cells
Authors: Louli Alex , Eldesoky Ahmed , Weber Rochelle , Genovese Matthew , Coon Matt , deGooyer Jack , Deng Zhe , White Robin T , Lee Jaehan , Rodgers Thomass , Dahn Jeff R. 
Published: December 2020

Anode-free lithium metal cells store 60% more energy per volume than conventional lithium ion cells. Such high energy density cells will enable electric vehicles with increased range and decreased cost. The anode-free strategy of using zero excess lithium presents a number of advantages and challenges over conventional lithium metal cells. Anode-free cells exhibit ultra-high stack energy density >1200 Wh/L for the NMC532 and 811 cells investigated in this work. Lithium metal cells, on the other hand, with lithium foils thicker than 60 µm are actually less energy dense than lithium ion cells. Challenges associated with manufacturing thin lithium foils and their incorporation in cell production are avoided in anode-free cells. Safety is a concern for any cell with metallic lithium, although this often remains unaddressed in the literature. However, with no excess lithium, anode-free cells suffer from rapid capacity loss. Lifetimes of fewer than 40 cycles to 80% capacity are common. Increasing cycle life to hundreds of cycles is necessary to produce viable anode-free cells for electric vehicles.
Recently, we demonstrated state-of-the-art cycle life for anode-free cells utilizing a dual-salt carbonate-based electrolyte.1 This liquid electrolyte enabled a pristine lithium morphology of tightly packed lithium grains forming a smooth lithium mosaic, shown in Fig. 1a-b. In this present work, we probe the lithium morphology at different states of charge and conclude that this morphology is composed of lithium columns (Fig. 1c-e). Incredibly, the columnar lithium enabled by dual-salt electrolyte forms a matrix of dead lithium which facilitates reversible lithium deposition.
Unfortunately, this pristine morphology is not maintained. In this work, we characterize the degradation of anode-free cells with dual-salt electrolyte. We probe the deterioration of lithium morphology during aging with SEM and correlate this to electrolyte degradation. We observe increased lithium porosity via x-ray tomography and use acoustic transmission imaging to demonstrate electrolyte depletion. For safety characterization, we measure the temperature of cells during penetration with a nail and compare to cells made with other electrolytes promoted in the literature. Finally, we use the insights gained here to build anode-free cells that deliver a greater energy density than lithium ion cells for over 200 cycles. Although lifetime must still be increased, we believe anode-free lithium metal cells with liquid electrolyte present the most straightforward and lowest cost path towards viable high energy density lithium batteries.

Reference
s
:

[1] Rochelle Weber, Matthew Genovese, A. J. Louli, Samuel Hames, Cameron Martin, Ian G. Hill and J. R. Dahn, Nat. Energy, 4 (2019) 683-689.

Figure 1
(Invited) Computational Modeling of the Anode-Electrolyte Interface of Ca Ion Batteries
Authors: Smeu Manuel 
Published: December 2020

Rechargeable batteries are critical components of portable electronics, electric vehicles and grid storage. Li-ion is the dominant technology because of its low weight, large voltage and high capacity, but the demand for raw materials is putting strain on the supply chain, and there are several safety, ethical and environmental concerns. Therefore, developing adequate alternatives to Li-ion batteries is an active research area around the world. Multivalent ion batteries (MVIBs), utilizing Mg, Ca, Zn and Al, are promising due to being based on earth-abundant materials, and their higher weight can be compensated by their multivalent nature, which allows their ions to carry multiple charges. We are particularly interested in Ca ion batteries, which have received relatively little attention compared to Mg and Al, yet they are predicted to provide the largest voltage for a multivalent ion. However, their development has been limited by challenges in identifying adequate electrolytes to reversibly plate and strip metal Ca anodes. While there have been some encouraging recent developments, a systematic understanding of the interactions between electrolytes and Ca is needed. For example, it is not clear how the electrolyte (e.g., ethylene carbonate) decomposes at a Ca metal surface, nor are the structure and composition known of the solid-electrolyte interphase (SEI) that forms between the metal anode and the electrolyte. Furthermore, the diffusion of Ca2+ ions through the SEI is not well understood.
We aim to address some of these points with computational modeling that combines density functional theory (DFT) with ab initio molecular dynamics (AIMD). We investigated the electrolyte decomposition of ethylene carbonate, with and without salt, at the Ca metal interface. We then compare this process to those occurring at Li and Al metal surfaces. The DFT calculations reveal the mechanism and energy barriers associated with the possible electrolyte decomposition pathways, while the AIMD trajectories show how quickly molecules decompose and their location. Next, we investigate the electron conductivity of the anode-electrolyte interface region at various stages of SEI layer formation. We accomplish this with the non-equilibrium Green’s function technique combined with DFT (NEGF-DFT), which not only tells us the conductivity but also the electron pathway through the interface. Finally, we investigate the possibility of protecting the electrolyte from reacting with the anode by separating them with an artificial SEI that still allows Ca2+ ions to diffuse through it. We propose that this strategy can aid in the development of rechargeable Ca ion batteries by bypassing the formation of an ionically insulating SEI as a result of electrolyte decomposition.
Graphene Functionalization As a Seed for Dielectric Passivation
Authors: Wyndaele Pieter-Jan , de Marneffe Jean-Francois , De Gendt Stefan 
Published: December 2020

Two-dimensional (2D) semiconductor materials like Transition Metal Dichalcogenides (TMDCs) are prominent candidates to replace silicon (Si) as channel material in the future (Si-based) transistors. However, to fully exploit the superior properties of 2D TMDCs, their inherent problem of basal-plane inertness needs to be resolved to enable dielectric passivation layer growth. Therefore, the objective of this work is to explore innovative options to enable high-k growth on 2D materials.
A literature study is provided, setting out how 2D materials became of interest to the microelectronic industry as a results of continuous device downscaling. To overcome the issue of basal plane inertness, a single layer graphene is used that acts as a sacrificial growth template. This graphene layer is deposited on top of a base layer (e.g. 2D material), whereby the graphene layer is chemically activated via a dry UV/ozone treatment, while preserving the properties of the underlying 2D layer.
Initial experiments focus on the removal of polymer-based transfer residues that typically remain on the graphene surface after transfer. Mechanical scratching atomic force microscopy shows that hydrogen plasma treatments are an effective and time-efficient method to remove polymer transfer residues. However, the plasma exposure also induces surface modifications as demonstrated by Raman characterization.
Next, the growth template is chemically activated by gently oxidizing the graphene layer via a dry UV/ozone treatment. The UV/ozone process characteristics are explored in function of the graphene cleaning treatments developed in the previous stage. For as-received graphene an operating window of 2-5 minutes of UV/ozone exposure is defined in order to maximize the oxidation degree, and thus nucleation sites. Activation is in balance with graphene layer damage or removal. The process is evaluated based on contact angle measurements, Raman and conductivity atomic force microscopy characterization.
Lastly, an atomic layer deposition study is carried out that focuses on high-k deposition on the activated single layer graphene to provide a proof-of-concept of enhanced dielectric growth in function cleaning and activation treatments developed in the preceding stages. Rutherford backscattering spectroscopy demonstrates the importance of a well-functionalized surface to achieve good material growth.
Routes to Novel Dielectric and Semiconductor Devices Using Cyclohexasilane
Authors: Elgammal Ramez Ahmed 
Published: December 2020

A newly developed “liquid silicon” precursor will be discussed. Cyclohexasilane (CHS; Si6H12) has been used to make silicon-based films (such as polysilicon, silicon nitride, silicon carbide and others), as well as silicon nanowires and quantum dots. CHS offers a more versatile, lower-cost and safer pathway to a variety of silicon based products being considered for flexible and printable electronics.
There is a need for a silicon precursor that is not only cost effective, but one that can be readily chemically functionalized to develop advanced materials. CHS is one such silicon precursor that is a liquid at room temperature allowing for easier storage and handling. Cyclohexasilane has a moderate boiling point, 80 °C at 15 torr. It has long been considered to be the preeminent silicon precursor for a variety of applications including semiconductor devices and can create thin films of β-SiC on a variety of substrates under mild conditions including conventional CVD; but also LPCVD, APCVD, and laser assisted CVD. The growth rate of β-SiC using CHS is an order of magnitude faster compared to other silicon precursors and the crystalline quality should rival materials grown by MBE.
Aside from those advantages, CHS allows for facile p-doping of materials into the β-SiC films such as aluminum and due to the methods of deposition and the deposition conditions amenable to a reagent such as CHS, continuous growth with the suppression of unintentional secondary deposits may be readily achieved. Moreover, it may be possible to use CHS to achieve solution growth to deliver high structural quality SiC with significantly decreased capital and operational costs.
The use of CHS across a wide range of industries and applications will be discussed as will the advantages of this material over incumbent technologies.