bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Impedance Analysis on Hydrogen Penetration Mechanisms on Steel
Authors: Fukada Haruka , Hoshi Yoshinao , Shitanda Isao , Itagaki Masayuki 
Published: February 2020

Environmental degradation of steels associated with the hydrogen embrittlement has been a serious problem worldwide. The hydrogen evolution reaction (HER) on steel has been studied by some electrochemical methods [1-3] in order to explore the hydrogen penetration behavior on steel. In the present study, the electrochemical impedance spectroscopy was applied to the investigation of the hydrogen reaction mechanisms on steel because the time constants observed in impedance spectrum can be discriminated.
The reaction scheme of HER on a metal were proposed to be a multistep as described below [4].
H+ + M + e- → MHads (1)
MHads + H3O+ + e- → H2 + H2O + M (2)
The reaction related to the hydrogen adsorption and absorption on steel was expressed by the following reaction [4].
MHads ↔ MHabs (3)
In these reactions, the M is metal, the MHad is the hydrogen adsorption, the MHab is the hydrogen absorption. The first step (Eq. (1)) and the second step (Eq. (2)) are Volmer reaction and Heyrovsky reaction, respectively. The third step is the hydrogen penetration reaction on steel. The reactions (2) and (3) are competition reactions when the MHad generated by the reaction (1). In order to investigate these competition reactions, the Faraday impedance simulations were carried out based on these reactions. When the reaction rate constant of hydrogen penetration reaction is small compared to the HER, the capacitive loop related to the electrode/solution interface was observed in the high frequency range and the capacitive loop appeared in the low frequency range. In the case of the large reaction rate constant of hydrogen penetration compared to the HER, the impedance spectrum described the capacitive loop related to the electrode/solution interface in the high frequency range and the inductive loop in the low frequency range, respectively. These results indicated that the low frequency impedance is related to the rate-determining step of the reactions (2) or (3). The electrochemical impedance measurement of steel was performed under potentiotatic polarization in order to discuss the HER and the hydrogen penetration mechanisms on steel based on the results of simulations.
References:
[1] M. A. Devanathan and Z. Stachurski, J. Electrochem. Soc., 111, 619 (1964).
[2] J. O'M. Bockris, J. McBreen, and L. Nanis, J. Electrochem. Soc, 112, 1025 (1965).
[3] E. Tada and A. Nishikata, ISJ internatonal, 56, 424 (2016).
[4] C. Gabrielli, P. P. Grand, A. Lasia and H. Perrot, Electrochemical Society Proceedings, 16, 147 (2000).
Corrosion Protection of Mg Based Alloy in Neutral Sodium Chloride Solution By Electrodeposited Ni-TiO2 – Silane Composite Coating
Authors: BinSabt Mohammad , Al-Kharafi Faizah M , Abditon Maryam , Galal Ahmed 
Published: February 2020

The electrochemical behavior of magnesium based alloy (composition Mg(93) Zn(1) Al(6) alloy) is studied in corrosive media of 3.5% NaCl aqueous electrolyte solution. Electrochemical techniques including D.C polarization and electrochemical impedance (EIS) measurements are used to characterize the behavior of the alloy. The data indicated the direct dissolution of the alloy as evidenced from ICP measurements and surface examination after exposure to the corrosive media. The alloy then was treated with a silane-polymer coating that proved effective protection to the surface of the alloy against corrosion.
Another approach is applied to improve the corrosion protection ability and film quality to the magnesium-based alloy based on the electro – deposition of another metal layer on top of the surface of the alloy. The Ni/TiO2 – silane composite layer was applied to the electrode to serve as a protective layer for the alloy. First the nickel and TiO2 nanoparticles was applied to the surface of the alloy followed by a protective silane film either by sequential spin-coating or layer-by-layer spin-coating. The protecting film is composed of 1,2bis(triethoxysilyl)ethanepoly(vinyl alcohol) hybrid (TESEPVA). Surface examination of the alloy or film-coated alloy was performed before and after exposure to the corroding electrolyte. The surface techniques used are field-emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray analysis, X-ray photoelectron spectroscopy (XPS) and surface enhanced Raman spectroscopy (SERS). The film thickness and surface wettability were also determined with the film displaying relative increase in the hydrophobic character.
Corrosion Behavior of Electrodeposited Znfe Sacrificial Coatings in Saline Solution: Alternative to Conventional Electrodeposited Sacrificial Coatings
Authors: Baissac Lucas , Arrighi Céline , Savall Catherine , Creus Juan , Rolet Jason 
Published: February 2020

Surface treatment and especially metal plating is a key process in the mechanical industry. It allows to protect structural and mechanical parts from degradation and prolongs their service life. To protect steel against corrosion, sacrificial coatings are widely used, and zinc coatings are often applied in this scope. However, the kinetic of zinc galvanic corrosion is very important. To overcome this problem, more noble elements are codeposited, involving the use of harmful metal salts, for instance nickel (II) salts. The industrial use of these salts is more and more restricted and regulated all over the world. Many alternatives are proposed, the more promising consisting in zinc-iron alloy electrodeposition with high iron content. The Atlas project (Alternative TechnoLogies for improved Anticorrosion Solutions), which is a large industrial consortium, is born in order to develop the ZnFe coatings properties and the knowledge of its corrosion mechanism.
The corrosion behaviors of commercial ZnFe electrodeposited coatings were investigated in 3.5 % NaCl solution. Corrosion potential is shifted towards more positive values, limiting the risk of galvanic corrosion with the substrate compared with pure zinc coatings. Sacrificial protection is evaluated with potentiodynamic tests, and longtime open circuit potential immersion is performed in order to analyze corrosion products. Other industrial sacrificial coatings performances are evaluated as a reference for those new ZnFe sacrificial coatings.
(Invited) From liquid to Solid: Solid State Electrolytes and Post-Lithium-Ion Electrochemistry
Authors: Hintennach Andreas 
Published: February 2020

Ever since the development of lithium-ion batteries the spirit of invention has mainly lead to an evolution of existing materials. With the focus on olivine and Nickel- and cobalt based materials the energy densities, power densities and ageing mechanisms could be investigated over the years and support the understanding of the underlying mechanisms of electrochemical energy storage and conversion.
With increasing numbers of cells being used in the world the need of a post Lithium-Ion technology emerges due to a limited availability of highly pristine nickel and cobalt and increasing need for recycling, environmental protection and overall energy efficiency. Nevertheless there is still an ongoing and very promising approach for e. g. novel stoichiometries of NMC materials, olivine materials, and nickel-rich materials with can significantly increase the energy density. But due to some limitation in the field of raw materials availability, accessibility, and sustainability, low-cobalt or cobalt-free materials are of very high interest, too. For example LMR (LNMO) can be an ideal candidate. Due to the very high reactivity and potential (i. e. 4.5 V) these materials require highly stable electrolytes.
Finally, lithium-sulphur can lead to a highly recyclable, environmentally friendly system. Having a silicon-based anode (> 85 % Si) included both volumetric and gravimetric energy density can mean an interesting alternative to metal-oxide based materials.
With the increased energy density, safety becomes a more and more important aspect in thermodynamic and kinetic investigations of these materials. This aspect can lead to the development of non-flammable electrolytes or solid state cells.
Solid state cells are a very different but highly promising approach. Having a solid-solid interphase between electroactive materials and electrolyte the chemicals mechanisms significantly change to solid state chemistry rather than solid-organic interphases chemistry.
All types of novel chemistries exhibit very different chemical mechanisms which require specific synthetically work, e. g. with the support of numerical simulation, for electrolytes, additives, binders, carbon materials, and even the surfaces of the electro-active materials itself. Understanding these mechanisms is essential to further improve the life-time, efficiency, and hence, the sustainability of any kind of energy storage and conversion, but batteries in particular.
(Plenary) Anion Redox in Metal Oxides
Authors: Shao-Horn Yang , Yu Yang , Charles Nenian 
Published: February 2020

Traditional Li-ion positive electrodes such as layered LiTMO2 (TM = Co, Ni, Mn) store lithium ions and electrons largely by employing the cationic redox of the transition metal (TM), yielding a capacity of ~140 mAh g-1 upon charging to 4.2 VLi. Recent advances on Li-overstoichiometric layered materials Li1+x
TM
1−yO2 (TM = Ti, Ni, Co, Mn, Ru, Ir) offer considerably greater first-cycle capacities than the conventional layered materials LiMO2 with over than 200 mAh g-1.1-4 The extra capacity can only be rationalized through the activation of anionic redox in those chemistries, in addition to conventional cationic redox mechanism. However, by tuning transition metal species, researchers observed different reversibility of the anionic redox process, inducing drastically distinct capacity fade over charge and discharge. 1, 3-4 To fully utilize and harvest the extra capacity from oxygen redox process, a clear understanding the redox behavior of those materials is needed. In the past decades, there are several competing hypotheses proposed on the redox process of Li-rich layered materials5-7, but a governing anionic redox mechanism is still lacking.
In this work, we employed X-ray core-level spectroscopies, coupled with ab-initio calculations to first understand the redox processes and structural evolution of model systems exhibiting oxygen redox. Through this effort, we have presented a holistic picture of the anionic redox mechanism in the context of previously proposed redox schemes put forward by different researchers. Moreover, through leveraging the learning of the redox process of model materials, we systematically tuned the transition metal species in the metal oxygen framework in those Li-rich oxides, which allows us to pinpoint potential electronic-structure-based descriptors to capture the activation and reversibility of the anionic redox process. This study has laid the foundation for future high-throughput screening of new generation high-energy-density positive electrodes for Li-ion batteries.

References

1.Thackeray, M. M.; Johnson, C. S.; Vaughey, J. T.; Li, N.; Hackney, S. A., Journal of Materials Chemistry
2005,
15 (23), 2257-2267.
2.Sathiya, M.; Rousse, G.; Ramesha, K.; Laisa, C.; Vezin, H.; Sougrati, M. T.; Doublet, M.-L.; Foix, D.; Gonbeau, D.; Walker, W., Nature Materials
2013,
12 (9), 827-835.
3.Yabuuchi, N.; Nakayama, M.; Takeuchi, M.; Komaba, S.; Hashimoto, Y.; Mukai, T.; Shiiba, H.; Sato, K.; Kobayashi, Y.; Nakao, A., Nature Communications
2016,
7, 13814.
4.Perez, A. J.; Jacquet, Q.; Batuk, D.; Iadecola, A.; Saubanère, M.; Rousse, G.; Larcher, D.; Vezin, H.; Doublet, M.-L.; Tarascon, J.-M., Nature Energy
2017,
2 (12), 954.
5.Gent, W. E.; Lim, K.; Liang, Y.; Li, Q.; Barnes, T.; Ahn, S.-J.; Stone, K. H.; McIntire, M.; Hong, J.; Song, J. H., Nature Communications
2017,
8 (1), 2091.
6.Seo, D.-H.; Lee, J.; Urban, A.; Malik, R.; Kang, S.; Ceder, G., Nature Chemistry
2016,
8 (7), 692-697.
7.Saubanère, M.; McCalla, E.; Tarascon, J.-M.; Doublet, M.-L., Energy & Environmental Science
2016,
9 (3), 984-991.
(Invited) DFT-Assisted Solid State NMR Characterization of Defects in Vanadium Fluorophosphates As Battery Materials
Authors: Carlier Dany , Bamine Tahya , Sanz Camacho Paula , Nguyen Hoang Bao Long , Broux Thibault , Masquelier Christian , Croguennec Laurence 
Published: February 2020

For energy storage, nowadays, Li-ion and Na-ion batteries are major technologies for mobility applications and also for large-scale storage of energy and their integration in the grid. In the scope of finding new positive electrode materials with improved performances, the deep understanding of the link between their structure, electronic structure and electrochemical behavior is crucial. As the presence of defects or disorder may play a critical role, a local characterization of the materials is highly required. To that extent, Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) appeared to be a key tool. For paramagnetic materials, it allows to probe both, the local structure and the local electronic structure thanks to the Fermi contact interaction. In order to assign the signals and understand the spin transfer mechanism through the chemical bonds, we have been developed the use of ab initio calculations for some years.
Some recent studies of the characterization of defects or disorder in layered oxides or V-phosphate materials will be presented. Using MAS-NMR we showed that several phosphate materials as LiVPO4F, or Na3V2(PO4)2F3, which are promising materials for positive electrode application in Li-ion and Na-ion batteries respectively, exhibit some O-defects leading to the formation of V4+ ions locally. These V4+ ions are forming a vanadyl-type bond with the defect O, and affect the electrochemical cycling performances.
Investigation of Capacity Fading on Li-Rich Layered Composite Cathode Materials for Li Ion Batteries
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Chang Chia Chin , Chang Li-Fu , Huang Bo-Yuan 
Published: February 2020

the capacity of Li-rich layered cathode powder was strongly affected by its particle size. By using sol-gel process, particle size of Li1.2Mn0.54Ni0.13Co0.13O2 powder obtained is around 200 nm. On the other hand, Li1.2Mn0.54Ni0.13Co0.13O2 powder synthesized by solid-state reaction method gives particle size as coarse as 1.0μm. The initial discharge capacity of sol-gel processed Li-rich cathode was 250 mAh/g. After 40 cycles, the discharge capacity from the same cathode still shows a capacity as high as 205 mAh/g. However, for cathode powder from solid-state reaction, its initial capacity was 190 mAh/g that is 24% lower than that of sol-gel processed cathode. After 40 cycles, the capacity degraded to 137 mAh/g. The enhanced capacity of sol-gel processed Li-rich cathode is attributed to its enormous surface area and short Li diffusion distance provided for electrochemical reaction to take place.
Furthermore, the TEM diffraction analysis of cycled Li[Li0.2Mn0.54Ni0.13Co0.13]O2 shows the evidence of spinel phase after cycling. It is believed that the transition from layered structure to spinel structure may also induce a large lattice distortion resulting in lattice breakdown and capacity fading. In additions, the phase transition may be caused by the redox reaction of transition metal ions through charging/discharging tests.
Preparation and Characterization of α-MnO2 Nanoplatelets/Onion like Carbon (OLC) Composite: High Capacity and Long-Cycle Life Rechargeable Sodium Ion Batteries
Authors: Palaniyandy Nithyadharseni , Modibedi Remegia Mmalewane , K. Mathe Mkhulu 
Published: February 2020

Sodium ion batteries (SIBs) continue to receive a tremendous exposure due to its natural abundance (2.6 wt. %, compared to lithium (0.06%)), cost effective and similar chemical and electrochemical properties to the lithium ion batteries (LIBs). However SIBs are still suffering with low energy density and long cycle life which impedes the wide applications and its development of SIBs. These drawbacks such as higher redox potential (-2.71 V vs. SHE), higher atomic mass (23 g mol-1) and large ionic radii (1.02 Å) of sodium metal facing a challenge for the choice of the electrode materials for the SIBs. Therefore, it’s necessary to use suitable cathode materials in order to occupy the sodium ions during insertion and de-insertion process [1-2].
In this case, numerous cathode materials have been investigated for SIBs such as layered transition metal oxides, fluoride-based sulfates and phosphates, olivins, and NASICONs [3-5]. However, their electrochemical performance (specific capacity, long-term cyclability and rate capability performance) as reported is not satisfactory. Thus, the finding of suitable electrode materials is a key challenge for the development of high-performance SIBs [6].
Manganese dioxide is known for large open tunnels, which can provide interstitial spaces for Na-ion storage and transport. Also, manganese dioxide is highly abundant, low cost and environmental benign. Therefore, in this work, α-MnO2 nanoplatelets/OLC composite was explored as cathode material and has been synthesized by microwave irradiation method using electrolytic manganese oxide (EMD). The physical and chemical characterizations of materials reveal single phase, Mn valence state and its nanoplatelet morphology. The electrochemistry of the fabricated cells was examined by cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. The α-MnO2 nanoplatelets/OLC composite exhibits highly stable and better capacity retention compared to pure α-MnO2 nanoplatelets cathode materials. In this discussion, the explored detail of the material and its preparation, physical and electrochemical properties of α-MnO2 nanoplatelets and its composite cathode materials for the application of Na-ion batteries will be presented.

References:

[1] D. Su, et al., J. Mater. Chem. A, 1, 4845-4850 (2013)
[2] J. Y. Hwang, et al. Chem. Soc. Rev., 46, 3529-3614 (2017)
[3] S. Guo, et al. Angew. Chem. Int. Ed., 54, 5894-5899 (2015)
[4] Funeka P. Nkosi, et al. J. Electrochem. Soc., 164 (13), A3362-A3370 (2017)
[5] F. Yang, et al., Small Methods, 1, 1700216 (2017)
[6] D. Su, et al., Npg Asia Materials, 5, e70 (2013)
Charge-Discharge Mechanism of All-Solid-State Batteries Using Li2RuO3-Li2so4 Positive Electrode Active Materials
Authors: Nagao Kenji , Sakuda Atsushi , Hayashi Akitoshi , Deguchi Minako , Hotehama Chie , Tsukasaki Hirofumi , Mori Shigeo , Orikasa Yuki , Yamamoto Kentaro , Uchimoto Yoshiharu , Tatsumisago Masahiro 
Published: February 2020

All-solid-state batteries have attracted great attention because of their high safety owing to the use of non-flammable inorganic solid electrolytes. Solid electrolytes with an extremely high ionic conductivity have already been discovered, and therefore the discovery of new and efficient electrode materials is key for the construction of high energy density all-solid-state batteries. In the electrode layers for conventional all-solid-state batteries, mixtures composed of active material, solid electrolyte and carbon conductive additive powders are often applied to secure lithium ionic and electronic conduction pathways. Moreover, most of all-solid-state batteries reported so far comprise a thin electrode layer with a small amount of active materials and a thick electrolyte layer as the separator. Therefore, the energy density of all-solid-state batteries at the present stage is considerably lower than that of typical lithium ion batteries. To enhance the energy density of all-solid-state batteries, high capacity electrode materials should be developed and the active material content should be increased in the composite electrode layers.
With consideration to the demands and features described above, we have successfully developed a novel Li2Ru0.8S0.2O3.2 (80Li2RuO3·20Li2SO4 in mol%) positive electrode material for all-solid-state batteries. Mechanochemical treatment with Li2SO4 imparts ionic conductivity and favourable ductility to the Li2RuO3 active material. Because of the favourable formability and high electronic and ionic conductivities, we achieved the fabrication of all-solid-state cells, where the positive electrode layer was composed of the active material without any conductive additives. The all-solid-state cell using a monolithic Li2Ru0.8S0.2O3.2 positive electrode functioned as a secondary battery showing a high reversible capacity of about 270 mAh g-1. In this study, the detail charge-discharge mechanism of the Li2Ru0.8S0.2O3.2 positive electrode was investigated by XRD, TEM, XPS, and XAFS measurements.
Operando Neutron Imaging for Next-Generation Solid State Batteries: A Direct Visualization of Li-Ion Transport in Sulfide Materials
Authors: Hoeltschi Laura , Cochet Magali , Trtik Pavel , Jordy Christian , Villevieille Claire , Boillat Pierre 
Published: February 2020

Li-ion all-solid-state batteries promise to enhance safety and performance compared to conventional liquid based batteries. Nevertheless, only few investigations have been carried out on the effect of the solid electrolyte’s ionic conductivity on the electrochemical performance of batteries in order to visualize non-uniform fields of transport.
Neutron Imaging (NI) is a non-intrusive technique that offers the possibility of tracking light elements such as the 6Li isotope during all phases of battery operation. Because it helps visualizing lithium’s concentration profiles, NI allows quantifying Li-ion transport and enables us to model solid state batteries. We therefore expect NI to help us explain solid state batteries’ poor rate capabilities. A reliable electrochemical cell was successfully designed and utilized for an operando test of an all-solid-state battery using PSI's high-resolution neutron imaging detector ('Neutron Microscope') at the POLDI beamline of Swiss Spallation Neutron Source SINQ (Paul Scherrer Institut). A solid state battery with a composite electrode TiS2:6Li3PS4(6LPS) and a 6Li-In alloy counter electrode have been investigated (Figure 1) and the results will be discussed.

Figure 1