bluuebunny/crossref_metadata_2025 huggingface dataset:
Muli-Bath Electrodeposition of CTZS Increasing Sulfur Ratio Close to Back Contact
Authors: Saeed Mahfouz Ali
Published: February 2020

Cu2(ZnSn)(S)4 (CTZS) has several good optical properties compared with other thin solid films. Producing CTZS cell layers by electrodeposition techniques is mostly attractive due to its low cost compared with other common deposition methods. According to literature review, there are serious challenges to deposit CTZS by electrochemical technique. The most challenging issue is sulfur atomic ratio which is about 50% of CTZS alloy.

We introduce in this work multi-steps electrodepostion techniques on order to obtain the desired atomic composition. First step is electroplating sulfur layer on the molybdenum back contact for 5 minutes followed by CTZS low sulfur layer, the third step is electroplating sulfur again for 8 minutes, the final step is electroplating CTZS low sulfur layer for 12 minutes. Electrolyte composition of sulfur electrodeposition: was 0.085 M CuSO4 and 0.074 M Na2S2O3. Electrolyte composition of CTZS electrodeposition is similar to the previous work used in the literature 1-4. The bath composition is: 0.053 M CuSO4, 0.04 M ZnSO4, 0.086 M SnCl2, 0.075 M Na2S2O3, and 0.055 M Na2S2O3. PHydrion is used to buffer the electrolyte to pH=2, and supporting electrolyte is 0.6 M LiCl.

Experiments were conducted at a rotating disk electrode in order to control and characterize the flow (Ambient temperature). The annealing post treatment is conducted on tube furnace under sulfur atmosphere for 55 minutes with no extra material addition on gas phase. Alloy surface analyses of CTZS from single bath and from multi-steps electrodeposition are in Fig. 1 and 2. The effects of both, bath composition and the electroplating time were optimized and discussed on this work. The amount of sulfur on the absorber layer was optimized by different run of multi-step electroplating technique. The alloy composition was examined using Energy-dispersive X-ray spectroscopy technique (EDS). XRD analysis method was used to characterized CTZS thickness and final crystallography.

Acknowledgements

Case Western Reserve University for using their instruments

References

[1] M. Cao, L. Li, B. L. Zhang, J. Huang, L. J. Wang, Y. Shen, Y. Sun, J. C. Jiang, G. J. Hu,

Sol. Energy Mater. Sol.Cells, 93, 583 (2009).

[2] Y. Lin, S. Ikeda, W. Septina, Y. Kawasaki, T. Harada, M. Matsumura, Sol. Energy Mater. Sol. Cells, 120,

218 (2014).

[3] Lee SG, Kim J, Woo HS, Jo Y, Inamdar AI, et al. Current Applied Physics 14: 254-258 (2014.

[4] R. Bhattacharya , J. Kim. The Open Surface Science Journal 4: 19-24 (2012).

Figure 1
Advanced Polyphthalocyanine–Derived Electrode Materials for Energy Storage and Conversion
Authors: Liu Lu , Yang Shaoxuan , Qin Yeshen , Zhang Zhengping , Wang Feng
Published: February 2020

Metal phthalocyanine, as one of the important synthetic metal-organic compounds, is similar with the natural metal porphyrins. Thanks to its unique structure and properties, phthalocyanines are constantly refurbished and excavated from blue dyes to third-order nonlinear optical materials, supramolecular self-assemblies, photoelectric-conversion materials, and liquid crystal materials. Since the cobalt phthalocyanine has been found with the electrocatalytic activity for oxygen reduction in 1964, the extensive researches on phthalocyanine-based compounds have been carried out in electrocatalysis and beyond. As the cross-linked products of phthalocyanines, polyphthalocyanines have a unique conjugated layered morphology with the various metal-N coordinated structure, demonstrating as the rational and facile materials and/ or precursors to construct the efficient electrode for energy conversion and storage device. In this work, we will present some of our rational and scalable strategies for developing the multi-variate and multi-scale materials from polyphthalocyanine for various renewable energy applications, including fuel cells, metal-air batteries, water splitting and supercapacitors. We anticipate that our strategies and electrode materials will also be useful for other electrochemical applications.

Figure Caption: Polyphthalocyanine-derived multi-functional materials for electrochemical applications.

Figure 1
Homogeneous and Heterogeneous Porphyrin Architectures for Electrocatalysis
Authors: Moore Gary F. , Wadsworth Brian L. , Khusnutdinova Diana , Flores Marco , Beiler Anna M. , Reyes Cruz Edgar A. , Zenkov Yegor , Urbine Jenifer M.
Published: February 2020

Catalysts are central to energy conversion in biology and technology; they provide low-energy pathways for steering chemical transformations and are used in applications ranging from manufacturing fuels and fine chemicals to controlling the bioenergetic reactions essential to all living organisms. Accordingly, the study of homogeneous molecular catalysts, including porphyrins, has provided researchers significant insights regarding the mechanisms and structure−function relationships governing myriad catalytic processes, as well as design principles for further improving the performance of human-engineered catalysts. Our research group has recently reported on the favorable catalytic properties of pi-extended porphyrins for hydrogen evolution, demonstrating the promise of extended macrocycles as a design element and structural motif for preparing electrocatalysts. [1-5] The pi-extended architecture provides an alternative strategy, compared to using electron-withdrawing or electron-donating functional groups, for adjusting the redox properties of a molecular catalyst and thus a promising avenue for catalyst design warranting further analysis.

D. Khusnutdinova, B. L. Wadsworth, M. Flores, A. M. Beiler, E. A. Reyes Cruz, Y. Zenkov, G. F. Moore, ACS Catal., 8, 9888–9898 (2018); DOI: 10.1021/acscatal.8b01776

D. Khusnutdinova, A. M. Beiler, B. L. Wadsworth, S. I. Jacob, G. F. Moore, Chem. Sci., 8, 253–259 (2017); DOI: 10.1039/c6sc02664h

A. M. Beiler, D. Khusnutdinova, B. L. Wadsworth, G. F. Moore, Inorg. Chem., 56, 12178–12185 (2017); DOI:10.1021/acs.inorgchem.7b01509

A. M. Beiler, D. Khusnutdinova, S. I. Jacob, G. F. Moore, ACS Appl. Mater. Interfaces, 8, 10038–10043 (2016); DOI: 10.1021/acsami.6b01557

B. L. Wadsworth, A. M. Beiler, D. Khusnutdinova, S. I. Jacob, G. F. Moore, ACS Catal., 6, 8048–8057 (2016); DOI: 10.1021/acscatal.6b02194
Self-Assembly and Sensing Properties of Rim-Functionalized Oxoporphyrinogens
Authors: Hill Jonathan P. , Chahal Mandeep Kaur , Labuta Jan , Payne Daniel , Webre Whitney , D'Souza Francis , Ariga Katsuhiko
Published: February 2020

Simple oxoporphyrinogen derivatives have been shown to be excellent colorimetric sensors for a variety of analytes as well as being effective electron deficient components of photosynthetic model compounds. More recently, this family of compounds has grown to include rim-functionalized compounds, which also exhibit colorimetric properties. In this work, we have prepared a series of differently rim-functionalized oxoporphyrinogens and we will present their properties with respect to sensing, including selective anion binding and chirality sensing, and the photolytic properties of appropriately functionalized compounds. In particular, we demonstrate the importance of substituent identity on the selective anion binding and asymmetric interactions. Observations of the properties of the compounds under irradiation again reveal the importance of molecular structure and cofactor interactions for the photophysical properties of the compounds.
The Industrial Advantages of Arginine Capped Magnetite Nanoparticles
Authors: Kashanian Faezeh , Habibi-Rezaei Mehran
Published: February 2020

Nanoparticles-protein interactions have gained a lot of attentions in several fields including nano-bio safety, nano-bioscience, nano-biomedicine, and nano-biotechnology. Hence, in this study the effects of Fe3O4@Arg (RMNPs) on the lysozyme structure, refolding, and denaturation along with its electrostatically effect on amyloid aggregation of lysozyme have been investigated. RMNPs were synthesized based on the Massart method and XRD, SEM, FT-IR, VSM, and Zeta Potential (DLS) were applied to investigate its structural and morphological properties. In addition, ThT assay and SEM were utilized in order to monitoring the inhibiting activity of RMNPs and its effects on the amyloid fibrils. Kosmotropic and chaotropic effects of RMNPs on lysozyme are investigated at lower and higher RMNPs/protein ratios, respectively. The result of this study showed that the protein folding, helicity, and half-life are improved at a low concentration of RMNPs. RMNPs improved depolymerization and disassembly of aggregates by reducing the aggregation and destroying fibrils.
High Temperature Oxidation of Zircaloy-4 Under Conditions Simulating a Loss of Cooling Accident in Spent Fuel Pools Examined with Raman Imaging and 18O Tracer Techniques
Authors: Kasperski Anne , Guérain Mathieu , Gestin Mathilde , Duriez Christian , Mermoux Michel
Published: February 2020

Since the Fukushima accident, an increased attention is continuously paid to the vulnerability of the Spent Fuel Pools (SFPs). In SFPs, for different reasons, degradation of the fuel rods induced by oxidation in air-steam mixtures after dewatering is a major safety concern: (i) the cladding material is the only barrier left against fission product dissemination, (ii) the heat released by the oxidation reactions can overcome the residual decay heat of the fuel and may become the main driving force to the accident escalation, (iii) hydrogen production is a strong concern because of the presence of steam, (iv) presence of air in the atmosphere is known to be an aggravating factor because of the “catalytic” role of nitrogen on the oxidation mechanism.

In this study, high temperature oxidation tests in oxygen, air and air - steam atmospheres were performed with Zircaloy-4 cladding tubes and plates specimens. Because spent fuels are concerned, the presence of the corrosion oxide scale formed in reactor during in-service operation was also considered. The tests described in this study were restricted to the 700 – 950°C range, and mostly performed at 850°C. Raman imaging was used to examine the specimens after the oxidation tests, either directly at the oxide surface, or on metallographic preparations for cross-section examinations.

We first used new opportunities given by Raman imaging to analyze, at least qualitatively, the structural and mechanical phenomena involved in this particular corrosion phenomena. Indeed, this method can provide information on the nature of phases that are present in the scale and on the stress level with sub-micron spatial resolution. The different methods used to extract this information that is present in the Raman data will be described and discussed.

Moreover, isotopic substitution was also considered. Actually, Raman spectroscopy has also the ability to quantitatively extract the 18O distribution in a zirconia oxide scale after a two stage experiment with a fair accuracy. Raman imaging gave clear evidence for different characteristic distributions of 18O in the scales. Some of them have been correlated with the development of cracks and porosity in the oxide which allows the corroding medium to penetrate locally in the scales. Nitrogen appears to have no or limited influence on the oxygen diffusion, but is observed to reach the metal/oxide interface much faster than oxygen. Thus, we also emphasize the potential of this method to investigate the 18O distribution in such complex corrosion scales.
Comparative Study of Chloride and Fluoride Induced Al Pad Corrosion in Wire Bonded Packaging Assembly
Authors: Issac Goutham , Lambert Alexander , Asokan Muthappan , Yi William , Chyan Oliver
Published: February 2020

Microelectronics are used in virtually all electronic equipment’s nowadays ranging from medical instruments, automobiles, computers, cell phones and home appliances. Wirebonding process which connects the chip to the lead frame in IC packaging plays a very important role in the commercial production of IC’s. Chip usually consists of Al bond pads with Cu/Au wires. Thin film Al bond pads are easily vulnerable to corrosion in presence of contaminants and moisture. Bond pad corrosion is one of the common modes of corrosion failure in wire-bonded devices IC packaging. Improper rinsing, packaging and passivation defects allows moisture and contaminants into bondpads resulting in severe corrosion. Most common source of this corrosion comes from the presence of halide ions contamination as (Cl-, F-, Br- etc.) However, the corrosion morphology and the severity varies from different ions contamination as the chemistry governing the corrosion differs from one ion to another.

Our research is focused on key findings on corrosion of Aluminum bond pad due to chloride (Cl-) and fluoride (F-) contamination. Our central motivation is to identify this F- corrosion mechanism, so that it will help to develop a strategy to prevent it and study the comparison between Cl- and F- Corrosion using Micro-pattern corrosion screening technique, Wire-bonded device (WBD) and other characterization technique such as GC-MS, SEM and tafel. GC-MS reveals that H2 gas evolution is observed during Cl- corrosion of the WBD, whereas little or no H2 evolution is observed during F- corrosion. SEM and EDX reveals no presence of Cl- in the corroded areas of its corrosion, whereas strong F- signal is observed in F- corrosion of the bondpads revealing, that the corrosion products formed on the surface has very poor solubility showing that Cl- and F- has a complete different corrosion morphology. Striking contrasts in corrosion morphology observed during the Cl- and F- corrosion were explained in the present work and will lead to better understanding of factors influencing the bond pad corrosion leading to the wire bond failure in IC packaging devices. [Fig. 1]

Figure 1
Mechanistic Understanding of the Planarization Behavior of Low κ Organosilicate Glass Films with Beol Barrier Slurries
Authors: Mallikarjunan Anupama , Achtyl Jennifer , Yang Rung-Je , Huang Chen-Yuan , Chao Shih-Hsuan , Gan Lu , Ridgeway Robert , Schlueter James , Tsai Ming-Shih , Li Chris , O'Neill Mark
Published: February 2020

Low κ Organosilicate Glass (OSG) films are being proliferated into new IC device architectures with CMP requirements spanning a wide range (highly selective to non-selective, low polish rates to high polish rates). This study aims to understand the relationship between these OSG film properties (both bulk and surface) and their planarization response, especially removal rate (RR). Eight OSG films were polished along with TEOS oxide using two barrier slurries. The films ranged in carbon content from 8 to 24 % and in nanoindentation elastic modulus from 5.5 to 21.8 GPa. Counterintuitively, higher mechanical strength (i.e., hardness, elastic modulus) of the low κ film did not result in lower polish rates; but was in agreement with previously noted behavior [1]. Removal rates also did not correlate to key OSG film properties such as refractive index (RI), dielectric constant (κ), or total carbon content (by X-ray photoelectron spectroscopy). However, an inverse relationship was observed between RR and the bulk chemical bonding structure (Si-CH3/Si-O ratio) as determined by transmission infrared spectroscopy (FT-IR) measurements (see Figure 1). In addition, a correlation between RR and OSG film’s surface free energy post-polish (measured from water and diiodomethane contact angles) was also observed. Based on the above findings, a mechanistic understanding of low κ OSG polishing was developed.

[1] L. Matz, M. Haas, M. O’Neill, R. Sawayda, A. Meyers, in Advanced Metallization Conference (AMC) (eds A. J. McKerrow, Y. Shacham-Diamand, S. Shingubara and Y. Shimogaki), Materials Research Society, Warrandale, PA, 463 (2009)

Figure 1
Initial Study on the Polishing Performance of Silica Abrasive Size in Copper Barrier Chemical Mechanical Planarization (CMP)
Authors: Lee Gwangwon , Park Hyungsoon
Published: February 2020

In this study, two types of copper barrier metal slurries used. We analyze the abrasive particle size by light scattering and SEM. Under different particle size distribution, polishing performance discussed. As a result, the material removal rate is higher even in smaller abrasive mean size and defects are not problematic in a certain pitch size for yield.
Performance of Trizact™ Microreplicated Pad in W Buff Marathon Process
Authors: Simpson Alexander W , Stomberg Jaimie , Muradian David , LeHuu Duy , Loesch Chris , Laraia Vince
Published: February 2020

This work demonstrates the performance of a microreplicated pad used in a W buff polish process. 3M™ Trizact™ microreplicated pads consist of matrix designed asperitity and pore structures that can be tuned independently, into a wide variety of complex 3D structures. More uniform pad asperity diameter and height control allows for better wafer-pad contact interacions. Consequently, microreplicated pads have significantly higher contact area with the wafer surface compared to industry standard hard and soft pads. The unique heringbone groove design allows for efficient slurry transportation and uniform slurry flow distribution – enabling the potential for slurry saving and cost of ownership reduction.

The CMP wafer polish results show stable oxide RR (se Figure 1) and consistent W:Ox film selectivity over 3000 wafers. Wafer removal rate recovey was repeatablly fast following periods of wet idle. Stable uniformity/edge profile control were also achieved. Total defect counts were controlled and consistent throughout the duration of the 3000 wafer marathon run. Upon completion of the marathon run, the loss in pad asperity height loss was less than 3 microns (14 %) compared to initial asperity height illustrating the potential to extend the pad life significantly beyond 3000 wafers (see Figure 2). The results illustrate the benefit of micro-replicated asperities in CMP pads, These results are important because of the potential to improve pad performance and reduce the cost of CMP.

Figure 1
(Invited) Cobalt Damascene Chemistry for Advanced Interconnect
Authors: Najjar Elie , Sun Shaopeng
Published: February 2020

In recent years, cobalt has caught more and more attention as an alternative material to Cu as the material for interconnect in advanced semiconductor technology. For electronic devices, the desire of reduction in size, but increase in performance, has driven the development of the process of interconnect toward a direction that the feature size of interconnects becomes smaller, so more components can be integrated in a more limited area on electronics. As feature size shrinking, cobalt brings benefits over copper as the material of interconnects1: 1) cobalt can have less resistance as there can be less electron scattering than is seen with copper, 2) and cobalt is less mobile than copper thus reducing electromigration. Electrodeposition is well known for its low cost of ownership as a metallization process. To achieve void-free and seam-free fill by electrodeposition for a feature less than 10nm, a bottom-up fill is required, and it is one of most challenging process among modern semiconductor technology. Filling a feature, usually a trench or via, via bottom-up fill means that the metallization grows predominately from bottom.

MacDermid Enthone has developed a Co chemistry which can provide void-free and seam-free fill to feature < 10nm. Also, it can achieve leveled overburden with good uniformity. In Fig 1., it is a FIB/TEM image of a feature, post-seed opening ~8nm and A/R of ~10, filled by MacDermid Enthone Co chemistry. In this report, a proposed electrochemical bottom-up fill mechanism will be discussed to reveal the challenge of cobalt damascene for advanced interconnect, and how they are overcome by the latest MacDermid Enthone Co chemistry

Figure 1: FIB/STEM of a feature filled by MacDermid Enthone Co chemistry

References

J. Jezewski, J. S. Clarke, T. K. Indukuri, F. Gstrein and D. J. Zierath, US 2014/0183738A1 (2012)

Figure 1
Self-Annealing Behavior of Electroplated Cu in the Blind-Hole Structure
Authors: Yang Cheng-Hsien , Lee Yu-Wei , Lee Cheng-Yu , Huang Yu-Hsuan , Ho Cheng-En
Published: February 2020

Blind-hole (BH) metallization via electrolytic Cu fillings has become a critical technology for fabrication of high-density-interconnection (HDI) printed circuit boards in electronic industry because this technology provides excellent thermal and electrical conductivity and efficient utilization of space. The morphology and crystallographic orientation/texture of the Cu fillings governs the electrical, thermal, and mechanical properties of the interconnections, affecting the overall reliability of an electronic device. Although numerous publications concerning the self-annealing behavior (generally termed room-temperature recrystallization) of electroplated Cu, there is still limited information regarding such a time-dependent phenomenon in the BH structure. As the distributions of organic additives and current density in a BH structure is very different from on the flat substrate and is an important factor of Cu self-annealing, it is therefore of fundamental interest and importance to investigate the BH Cu microstructure transition in the self-annealing procedure. In this study, we probed into the crystallographic and resistance transitions of the Cu platings in a BH structure via an ohm meter and a field-emission scanning electron microscope (FE-SEM) in combination with electron backscatter diffraction (EBSD) analysis system. Additionally, the distribution of organic additives in a BH structure was characterized using a time of flight secondary ion mass spectrometer (TOF-SIMS). The knowledge advances our understanding of the evolution of the BH Cu filling physical/chemical properties during self-annealing.

Figure 1
Ag Membranes for Electrochemical CO2 to CO Conversion in an MEA Type Set-up
Authors: Seger Brian , Larrazabal Gaston , Strøm-Hansen Patrick , Heli Jens Peter , Therkildsen Kasper
Published: February 2020

While there has been a large push towards electrochemically derived fuels such as hydrogen, chemicals such as carbon monoxide have much more favorable economics(1) and are thus highly promising. Both Au and Ag are well-established catalysts for electrochemically producing CO,(2) but studies on upscaling these reactions to industrial relevant currents (> 100 mA/cm2) is lacking.

This talk will discuss our work on using Ag membranes for electrochemical CO2 to CO conversion in a membrane electrode assembly (MEA) device. The cathode is completely carbon free and can produce predominantly CO at currents up to 250 mA/cm2 (@ approximately 3 V), and thereafter significant H2 evolution starts to occur. Typical tests were 24 hours, but some longer-term data will be show, demonstrating the stability of the system. Variations in humidity from the gaseous cathode side had effects on both performance and durability. The anode electrolyte was a bicarbonate solution with either an accompanying K, Na, or Cs cation. Variations in the cations resulted in a notable performance change even though an anion exchange membrane was present. By inserting a reference electrode into our anode side we could separate our cathodic, anodic, and ionic losses, thus allowing us to better understand our system. The advantages, disadvantages, and engineering knowledge gained from this work will be summarized.

1) Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous Electrolyte. Nitopi et al., submitted 2018,

2) Electrocatalytic process of CO selectivity in electrochemical reduction of CO2 at metal electrodes in aqueous media. Hori et al., Electrochimica Acta, 1994, 39, 11-12, 1833-1839
Deposition of Dopamine Thin Film As an Adhesion Layer in Heterogeneous Interfaces for Metallization Process
Authors: Chou Shih-Cheng , Hung Pei-Sung , Wang Chuan-Jyun , Wang Guang-Ren , Chung Wei-An , Wu Pu-Wei
Published: February 2020

Metallization on patterned or insulating substrates possesses significant importance in various applications. However, there usually exhibit poor interfacial adhesion between metals and oxides/polymers. This is one of the major obstacles for this process in practical applications, such as integrated circuits and printed circuit board for wearable devices. In this research, we had successfully used dopamine as an adhesion layer in the heterogeneous interface, such as SiO2/Cu and polymer/Cu interfaces. The use of this reagent could act as both a reductant and interfacial adhesive. We performed SEM, TEM and EDS analysis to confirm the film structure and their compositions. Peeling test were also conducted for evaluating the enhancement of film adhesion with the introduction of dopamine. We expected this technique could be to apply in the thin film process in the near future.
Comparison of Electrochemical Degradation of Sulfonamides with BDD and Pt Electrodes
Authors: Li Hongna , Ye Jing , Zhu Changxiong
Published: February 2020

Electrochemical degradation of a series of sulfonamides (SNs) was investigated using both BDD and Pt anodes. SNs were destroyed faster in Na2SO4 than in NaH2PO4 electrolytes at the BDD anode, while the opposite occurred with Pt anode. In the BDD anode system, the degradation rates of SNs with a singly-substituted pyrimidine ring rose with the Hammett’s constants for both electrolytes. The structure of SNs had no significant effect on the degradation rates with the Pt anode. Accordingly, the mineralization rate of SNs with the BDD anode reached 28-45% in Na2SO4 electrolytes, and it decreased to 17-35% when using NaH2PO4 electrolytes in 6-h electrolysis. Further analysis indicated no difference for the intermediates in the electrochemical oxidation of sulfamethazine regardless of the anode used. Anyhow, the relative amount of these intermediates formed varied from BDD to Pt. The compound corresponding to an attack on the pyrimidine ring occupied a relatively higher ratio (M1, 0.3%) in the Pt system, while that associated with cleavage of the sulfonamide bond (M4, 16.7%) as well as M1 (6.7%) covered a large proportion with BDD in the first 1 hour of electrolysis. Due to the efficient oxidative ability of BDD anodes, larger amounts of intermediates with relatively high toxicity were generated initially and then declined. The formation of these intermediates continuously increased in the Pt system. The electrolysis conducted with BDD and Pt anodes were actually at different oxidation stages. For this reason, the electrochemical oxidation process with the BDD anode is advantageous because it accomplishes relatively more complete mineralization of organic pollutants.
Stress Evolution in Na-Ion Battery Anode during Electrochemical Cycling
Authors: Rakshit Subhajit , Ruiz Olivia , Detsi Eric , Nadimpalli Siva
Published: February 2020

A large amount of literature exists on the electrochemical characterization of various high capacity sodium-ion battery electrodes; however, their mechanical behavior has not been characterized before. In this study, evolution of stress in sodium-ion battery electrode has been measured in real-time using an optical-based substrate curvature measurement apparatus. A 100 nm Ge thin film, as working electrode, was cycled against sodium reference/counter electrode with 1 M sodium perchlorate (NaClO4) in propylene carbonate (PC) as electrolyte. Electrochemical and stress response of the electrodes to the prescribed electrochemical cycling conditions were measured simultaneously. Further, the sodiated Ge samples were analyzed using SEM, XRD, and AFM techniques to understand the microstructural changes. It was observed that sodiation of Ge films resulted in distinctly different mechanics and electrochemical phenomenon compared to that of lithiated Ge films. These observations and implications will be further discussed in the talk.
Nitrate Combustion Synthesis of NVP-Type Cathode Material for Na-Ion Batteries
Authors: Väli Ronald , Jänes Alar , Lust Enn
Published: February 2020

The synthesis and characterization of a Na3V2(PO4)3 cathode material for room-temperature sodium-ion battery is reported. The NVP material was prepared using a two-step process which proceeded via sol-gel nitrate combustion method for precursor preparation and subsequent pyrolysis under Argon.

The materials have been investigated using SEM, EDX, XRD and TOF-SIMS methods. Electrochemical characterization has been carried out using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge method (GCD).

The electrode slurry was prepared by mixing the active material, conductive additive (Super P) and polyvinylidene difluoride (PVdF) binder in a 75:15:10 mass ratio. The mixed slurry was cast onto aluminium foil using doctor-blade technique. The cast electrodes were dried under vacuum for 24h. Electrochemical tests were carried out in coin cells, which were assembled in an Argon-filled glovebox (O2 < 0.1 ppm, H2O < 0.1 ppm). Sodium metal was used as the counter electrode and 1M NaPF6 in EC:PC (1:1 vol) as the electrolyte in half-cell measurements.

Acknowledgements

The present study was supported by European Regional Development Fund (Centres of Excellence TK141 (2014-2020.4.01.15-0011)6, Higher education specialization stipends in smart specialization growth areas 2014-2020.4.02.16-0026), “Institutional development program for research and development and higher education institutions” (ASTRA) (Graduate School of Functional Materials and Technologies, Materials Technology Projects SLOKT12180T and SLOKT12181T, Energy Technology Project SLOKT10209T), Estonian Research Council (Institutional Research Grant IUT20–13 and by NAMUR project 3.2.0304.12-0397. Mr. Väli thanks Estonian Students Fund in USA for financial support.
A Dual Functional Artificial Solid Electrolyte Interphase for Dendrite-Free Lithium-Metal Batteries
Authors: Chiochan Poramane , Phattharasupakun Nutthaphon , Duangdangchote Salatan , Sawangphruk Montree
Published: February 2020

The lithium metal has been expected to be an anode of next-generation rechargeable lithium metal batteries due to its remarkable specific capacity of 3,860 mAh g-1, a low negative electrochemical potential (3.04 vs S.H.E.), and lightweight. To obtain high-energy batteries, the reactive Li anode should be coupled with the superior energy density cathode, for instance, sulfur and oxygen. However, the unrestrained Li dendrite formation and the undesired side reaction at both electrodes could cause the low coulombic efficiency and safety issues hindering the lithium metal batteries from the commercialization. Here, we demonstrate the dual functional artificial solid electrolyte interphases using the UIO-66(SO3) metal-organic framework/polyvinylidene fluoride film (UIO/PVDF). For the LI||Li batteries, the polymer matrix can stabilize the overpotential at a current density of 1.5 mA cm-2 over 200 cycles, indicating the suppression of lithium dendrite growth. When the UIO/PVDF film was applied to the lithium-sulfur batteries, it illustrates the bi-functional to prevent the Li dendrite formation and repulse the lithium polysulfide species. As a result, the electrochemical activities of both cathode and anode are improved.
Metrics of Hybrid Polymer/Ceramic Electrolyte for 21700 Cylindrical Solid-State Batteries Powering Electric Vehicles
Authors: Mao Chengyu , Kim Seung Wan , Liu Ying
Published: February 2020

All solid-state batteries have become the focus of next-generation Li-ion battery research and development to meet the ever-growing demands on safe and high-energy-density storage systems. Replacing conventional electrolytes with solids mitigates issues associated with flammable organic liquid and makes safer battery systems. Solid electrolytes which are stable against lithium and resistant to Li dendrite penetration could enable the use of metallic lithium anode, offering a promising pathway to deliver lithium-ion cells with energy densities that significantly exceeds 350 Wh/kg. While each main class of solid electrolytes has their intrinsic challenges, integrating different group of solid electrolytes such as polymers and ceramics has the potential of bringing their individual advantages together and overcoming their drawbacks. In this study, we fabricated a group of hybrid polymer/ceramic electrolytes made from commercially available materials. Their ionic conductivity, electrochemical stability, interfacial stability towards metallic lithium, thermal property, processability and mechanical strength were systematically investigated. Finally, we develop a metrics to screen these hybrid solid electrolytes for our 21700 cylindrical cell design and identify promising candidates which are most relevant to electric vehicles (EV) applications. Our study illustrates the importance of component integration in developing high-performance solid-state electrolyte. This work serves as a guide to select the appropriate solid electrolytes that can power future electric vehicles.
Effects of a Novel Fluorinated Linear Carbonate Additive on the High Voltage Performance of Lithium Ion Batteries
Authors: Dzakpasu Cyril Bubu , Roh Youngjoon , Byun Seoungwoo , Kim Ju Young , Kim Kwang Man , Ryou Myung-Hyun , Lee Yong Min
Published: February 2020

Lithium ion batteries (LIBs) are considered as suitable power sources for a variety of applications such as portable electronic devices and electric vehicles owing to their high energy density and long cycle life. To improve the energy density of LIBs, electrode materials with high reversible capacities; cathode materials that operate at high voltages and anode materials with low working potentials close to 0V vs. Li/Li+ have been developed. However, deterioration of the electrode-electrolyte interface causes unsatisfactory performance of batteries. Various approaches such as surface coating of electrode materials and the use of electrolyte additives have been proposed to stabilize the electrode-electrolyte interface. The use of reducible and oxidizable compounds for the formation of an artificial solid electrolyte interphase is one of the most effective strategies to improve the interfacial stability of electrodes.

In this study, we evaluate the performance of a novel fluorinated linear carbonate as an additive with LiNi0.8Co0.1Mn0.1O2 half-cells under high voltage conditions. The effect of the additive was characterized by linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and ex situ X-ray photoelectron spectroscopy (XPS). Overall, the additive was found to show an improvement in the cell performance.
Simultaneous MgO Coating and Mg Doping of Co-Free Cathode Material for High-Voltage Sodium-Ion Batteries
Authors: Yu Tae Yeon , Sun Yang-Kook
Published: February 2020

Over the past two decades, advancements in Li-ion battery (LIB) technologies have contributed immensely to changing our daily lives. Recently, another type of energy storage system, sodium-ion batteries (SIBs), have received significant attention mainly because of the abundance of sodium resources in the Earth's crust, which could thereby greatly reduce costs. Encouraged by previously conducted research activities in this field, we have adopted an effective strategy for simultaneous MgO coating and Mg doping to produce substantially improved high voltage stability compared to the previously reported results in the literature on Na[Ni0.5Mn0.5]O2 cathodes. The MgO coating layer effectively suppressed the unfavorable side reactions during cycling while the partial Mg doping into the bulk Ni sites improved the structural stability by moderating the extent of the irreversible multiphase transformation. As a result, the combination of a MgO coating with Mg doping provides enhanced electrochemical performance and structural stability of Na[Ni0.5Mn0.5]O2 within the voltage range of 2.0–4.2 V. The practical acceptability of the simultaneous MgO coating and Mg doping of the Na[Ni0.5Mn0.5]O2 cathode was obviously verified using scaled-up pouch-type full cells with hard carbon anodes. Moreover, the use of earth's abundant and inexpensive Mg and Na elements, and a simple practical strategy are highly desirable for developing high-energy and low-cost SIBs. Although the practical use of the MgO-NM55 cathode in SIBs will require further work, the methodology used in this study will be helpful in developing an efficient design of high performance cathode materials for SIBs.
In-Depth Analysis of Binder Distribution within Lithium-Ion Battery Electrode Using SAICAS
Authors: Byun Seoungwoo , Kim Kyuman , Choi Jaecheol , Ryou Myung-Hyun , Lee YongMin
Published: February 2020

Microstructure and mechanical properties of lithium-ion battery (LIB) electrodes become more important as their loading levels increase highly for acheiving high energy density. In this point of view, we should control polymeric binder materials as well as nano-sized conductive materials within LIB electrodes. However, due to the limitation of appropriate analysis tools, it remains one of the challenging issues in LIBs. Fortunately, we have started using a new analysis tool, surface and interfacial cutting analysis system (SAICAS, Daipla Witnes, Japan), to measure adhesion properties of LIB composite electrodes as a function of depths. Based on the general principle, the adhesion strength is approximately propotional to the binder content, the polymeric binder distribution within the electrodes can be unveiled with a SAICAS.

In this study, we prepared two LiCoO2 electrodes dried at totally different temperatures, 130 and 230oC, and used to confirm the feasibility to figure out the polymeric binder distribution in the electrode by using SAICAS. First, the adhesion strengths of those electrodes were deliberately measured at every 10 μm depth from the electrode surface as shown in Figure. Simultaneously, not only surface and cross-sectional SEM images but also corresponding EDS atomic mapping were checked to find correlation with adhesion strength. The electrochemical properties such as DC-IR, rate capability, and cycle life at room and high temperatures were also investigated.
Interconnected Porous Sb-C Nanocomposite As an Anode Material with High Capacity for K-Ion Batteries
Authors: Ki Hyeong-Seo , Verma Rakesh , Park Chan-Jin
Published: February 2020

With growing demand for clean and sustainable energy resources, lithium-ion batteries (LIBs) have been intensively developed and considered as one of the most successful energy storage devices in the past decades. However, the growth of LIBs has been restricted due to unevenly distributed and limited lithium natural resources. Therefore, numerous efforts have been devoted to finding the alternatives to LIBs such as sodium-ion batteries (SIBs) and potassium ion batteries (PIBs) due to their benefits of abundance and low cost resources. Moreover, redox potential of K+/K (-2.93 V vs. SHE) is lower than Na+/Na (-2.71 V vs. SHE), which indicates higher cell potential and energy density compared with that of SIBs. Recently, alloy type antimony (Sb) anode has attracted considerable attention as a promising anode materials for PIBs owing to its low and suitable potassiation potential for alloying/dealloying and high specific capacity corresponding to K3Sb phase. However, the large volumetric change during repetitive cycling may lead to pulverization of the active material and resultant rapid capacity fading. To address the issues, many strategies have been suggested such as nano-sized particles, porous structures, and embedding active materials into carbon layer thereby improving the cyclability of Sb-based anodes.

In this study, the interconnected porous Sb-carbon nanocomposite (Sb-C) was synthesized through simple citrate gel carbothermal reduction route with citric acid as a chealating agent and carbon source as well. The gel complex was calcined at different temperatures in N2 atmosphere for the carbothermal reduction affecting porosity of the Sb-C composites. The crystal structure, morphology and carbon content of the Sb-C composite were investigated by XRD, SEM, and TGA. Effect of the calcination temperature on the electrochemical performance of the Sb-C composite was investigated within a potential range from 0.01 V to 2.5 V vs. K/K+. The interconnected porous Sb-C nanocomposite exhibited the excellent electrochemical performance suitable as an anode material for PIBs.
Carbon Coated Tin Selenide Nanocomposite Anode Materials for Advanced Potassium-Ion Batteries
Authors: Verma Rakesh , Park Chan-Jin
Published: February 2020

Energy storage systems with high capacity and low cost are of primary concern in the development of electric vehicles and smart grids. Recently, room temperature potassium-ion batteries (PIBs), which possess the advantages of high theoretical capacity and the abundant earth reserves and low prices of K, becomes an attractive alternative to the conventional lithium-ion batteries (LIBs). Current efforts have focused on developing new alloy type materials to replace the existing carbonaceous based anode materials for PIBs because of the high theoretical specific capacity of the alloy type anodes. In particular, SnSe is a potential candidate anode material for PIBs due to the earth-abundance, environmental friendly, and chemically stableness. However, the SnSe can suffer from a poor cyclic performance and rate capability, which are mainly attributed to the large volume change during potassiation/depotassiation and the relatively low conductivity of SnSe, respectively.

In the present work, to address the issues related to SnSe, SnSe/C nanocomposite was prepared through a simple and low-cost high energy ball milling technique. The phase purity, morphology, and structure of the prepared materials were characterized by XRD, BET, Raman spectroscopy, SEM, and TEM. Further, when this SnSe/C nanocomposite was tested as an anode material for PIBs, it exhibited a good cycling performance and excellent rate capability. The good cycling performance and excellent rate capability could be ascribed to the well dispersion of SnSe within the SnSe/C nanocomposite, which enhanced the electrical conductivity and electrochemical kinetics of the whole anode material. Furthermore, the Super P carbon also acted as a buffer material to accommodate the huge volume change of SnSe particles during potassiation/depotassiation processes. Furthermore, the effect of the alloying/dealloying process on the crystal structure of SnSe/C was examined by the ex-situ XRD patterns recorded in various stages of discharge and charge. The potassiation/depotassiation mechanism was suggested.
In Situ Controlled Syntheses of Electrolyte Additives for High Voltage Lithium Ion Batteries
Authors: Liao Chen , Yang Jianzhong , Shkrob Ilya A , Zhang Zhengcheng , Gutierrez Arturo , Croy Jason R.
Published: February 2020

The development of cathode materials needs concomitant electrolyte developments to accommodate the high voltage to reach high energy and power densities required for electric vehicle and personal electronics. Previously we reported that aging TMSPi (trimethylsilylphosphite) additive in a standard 1.2 M LiPF6 carbonate electrolyte can generate a beneficial transient product, PF2(OSi(CH3)3), which was later proven to mitigate impedance rise during long term cycling in composite cathode-graphite cells. However, the generation of PF2(OSi(CH3)3) is spontaneous and cannot be controlled, and as aging process proceeds to a greater extent, PF2(OSi(CH3)3) disappears gradually and other transient detrimental products form along the way and eventually deteriorate the impedance.1,2

By using molecular engineering to tune functionality, ratio, and stability, we can control the in situ electrolyte additive to selectively synthesize the beneficial component in high yield (> 98%) and maximize the battery performance. The in situ method is particularly of interest to scale up electrolyte preparation since it would alleviate any requirements of extra separation and purification of the desired additives. By varying the structure of the additive precursor, we clearly see a trend that is governed by thermodynamics which determine the product ratio and composition. The electrochemistry of these additives and their application in composite cathodes will be discussed. By introducing the novel in situ synthetic method for electrolyte additive syntheses, avenues for new additives that were previously inaccessible will open up and facilitate the development of the lithium ion batteries toward high energy and high power density.

References

The Journal of Physical Chemistry C 2018, 122 (18), 9811-9824.

RSC Advances 2016, 6 (44), 38342-38349.
Sulfur Incorporated into Carbon Coated FeS2 Nanotubes for High-Performance Lithium-Sulfur Batteries
Authors: Zeng Zhipeng , Liu Xingbo
Published: February 2020

The high theoretical capacity (1672 mAh g-1) and energy density (2600 W h kg-1) for sulfur electrode make it be a very promising candidate for electric and hybrid electric vehicles among the various candidates. However, the practical application of this promising material is still greatly hindered by poor cycle stability and low Coulombic efficiency resulting from the notorious “shuttle effect” of polysulfides. To prevent the diffusion of polysulfides, more attention has been paid to utilize the chemical interactions between the functional groups on the host materials and lithium polysulfides (LiPSs).

The inexpensive, environmentally friendly and high-conductive pyrite-based materials show high catalytic activity in relation to polysulfides. Here, we report carbon coated FeS2 nanotubes as the sulfur host (FeS2@C-S) for Li-S batteries application. The carbon shell can facilitate fast kinetics of conversion between LiPSs and Li2S, resulting in the excellent rate capability. Meanwhile, the hollow space as the major chamber for sulfur storage can effectively accommodate the volume change during the charge/discharge process. In addition, the FeS2 with carbon shell can not only act as barrier layer but also provide strong chemical interaction force to prevent the LiPSs from diffusion. As a result, the FeS2@C-S electrode with unique structure combined physical confinement and chemical bonding to polysulfides exhibited excellent electrochemical performance, in terms of cycle stability, rate capability and Coulombic efficiency, showing the great potential application in developing high-performance Li-S batteries.
The Role of Electrolyte Additives on the Stability and Electrochemical Performance of Lithium-Sulfur Batteries
Authors: Duangdangchote Salatan , Krittayavathananon Atiweena , Phattharasupakun Nutthaphon , Sawangphruk Montree
Published: February 2020

Lithium-sulfur batteries (LSBs) are attractive owing to their high theoretical energy density (2600 Wh kg-1)1, low cost, and natural abundance. However, a major drawback of LSBs is an uncontrolled lithium dendrite formation during cycling leading to serious safety issue, low Coulombic efficiency and poor cycle performance. To overcome this drawback, electrolyte additives are typically used to control the lithium dendrite growth by chemically forming stable solid-electrolyte interphase (SEI) above the metallic Li anode. The SEI layers are formed via several steps with rather complex mechanisms2. To elucidate the mechanisms of SEI formation, in this work, many electrolyte additives with different anions (e.g., LiNO3, LiClO4, LiBr, LiI, LiBF4) have been investigated using computational chemistry calculations along with the experimental study to gain fundamental understanding. The different additives exhibit different reaction pathways with LiTFSI to form the decomposed products over lithium surface and directly correlate to the evolution of LiF. This affects the cell performance in terms of the coulombic efficiency and capacity retention. For example, the LiNO3 provides the highest efficiency while it gives poor capacity retention. LiClO4 can provide high capacity retention over cycling. We believe that this work will provide the understanding of the effect of the additives that can enhance overall performance and safety of lithium-sulfur batteries.

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Figure 1