bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization Capacitive Desalinzation Cell By Using the FeIII(CN)6
3-/FeII(CN)6
4- Redox Couple As an Electrochemical Probe
Authors: Sene Assane , Daffos Barbara , Taberna Pierre-Louis , Simon Patrice
Published: February 2020

Recently, a desalination technique based on porous carbon has been reported [1], merging together desalination process with electrochemical energy storage. Thanks to this new strategy, an important step forward, respect to other water desalination technologies, has been achieved. The principle is based on the capacitive adsorption of Na+ and Cl- ions in the pores of a porous activated carbon, constituting the active material of an electrochemical double layer capacitor electrode. Differently from conventional EDLC, the active material is made in the present case as slurries flowed through an electrochemical cell to achieve a continuous desalination of seat water; such system has been named Electrochemical Flow Capacitor (ELC) [2], [3].

The objective of the study is to improve the energy efficiency of the desalination process by optimizing the cell design and by selecting the proper activated carbon. To do so, we characterized a desalinization cell using different type of electrodes using the FeIII(CN)6
3-/FeII(CN)6
4- redox couple as an electrochemical probe. Our approach allowed to define a dimensionless number θ, which is proportional to the flow rate and inversely proportional to the potential scan rate, giving a guideline to sort out different operating regimes in the flow cell. Two operating regimes have been evidenced: a permanent regime for θ > 60, allowing for higher and efficient charge adsorption, and a non-permanent domain for θ < 60.

Références :

[1] M. E. Suss, S. Porada, X.Sun, P. M. Biesheuvel, J. Yoon and V. Presser, Energy Environ Sci., 20015, 8, 2296-2319.

[2] K. B. Hatzell, E. Iwama, A. Ferris, B. Daffos, K. Urita, T. Tzedakis,F. Chauvet, P. Taberna, Y. Gogotsi, P. Simon, Electrochemistry Communications 43 (2014) 18–21.

[3] Y. Gendel, A. K. E. Rommerskirchen, O. David, M. Wessling, Electrochemistry Communications 46 (2014) 152–156.
(Invited) Insights into Proton Transport in Superprotonic Solid Acids
Authors: Haile Sossina M
Published: February 2020

Superprotonic solid acid electrolytes, materials with chemical and physical properties intermediate between conventional acids (e.g., H3PO4) and conventional salts (e.g., Cs3PO4) have emerged as attractive candidates for fuel cell and other electrochemical applications. Key characteristics of these materials are tetrahedral oxyanion groups linked by hydrogen bonds, and a polymorphic structural transition to a disordered state at moderate temperatures. Rapid oxyanion reorientation and dynamic disorder of the hydrogen bond network facilitate high proton conductivity in the high temperature phase. Materials exhibiting a superprotonic transition include CsHSO4, Cs3H(SeO4)2, CsH2PO4, and Cs2(HSO4)(H2PO4). Here we review the present state of understanding of proton transport mechanisms and the factors governing the transition behavior as gathered from macroscale measurements of conductivity and thermal properties and from atomistic level studies using nuclear magnetic resonance spectroscopy. We focus in particular on CsH2PO4, the technologically most significant superprotonic solid acid, and its chemical modifications produced by substitution on either the alkali metal or proton site (deuterated materials). Dramatic changes in phase behavior and proton conductivity can be induced by only minor changes in chemistry, suggesting routes for tuning behavior to achieve desired outcomes.
(Invited) Thin Film Batteries Still Have Interesting Lessons for Lithium Batteries
Authors: Dudney Nancy J. , Westover Andrew S. , Veith Gabriel M. , Chi Miaofang , Kalnaus Sergiy
Published: February 2020

After several decades of R&D, the thin film batteries using ORNL’s Lipon glassy electrolyte is still a promising technology for consumer electronics. These batteries also serve as model systems for other solid-state battery efforts, as the thin film batteries demonstrate exceptional stability with extended cycling and wide ranges of voltage and temperature. In light of recent thermodynamic analysis [1], we need to ask - Are we cheating thermodynamics? This presentation will briefly review the early work on Lipon-based batteries leading into recent efforts to advance the understanding of Lipon properties. Results for stability of Lipon with high voltage cathodes and Li metal will be highlighted.

[1] William D. Richards, Lincoln J. Miara, Yan Wang, Jae Chul Kim, and Gerbrand Ceder, DOI: 10.1021/acs.chemmater.5b04082

Acknowledgement: This work is based on support from the US Department of Energy, Advanced Research Projects Agency for Energy (ARPA-E) IONICS program; and on earlier support from U. S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division.
(Invited) Harnessing the Architectural Power of Ionics: Electrolytically Formed Batteries
Authors: Scott Kimberly , Halajko Anna , Amatucci Glenn G
Published: February 2020

Ion diffusion represents the core challenge and a chronic weak link relative to the transport of its parallel counterpart, the electron. As such, decades of ground breaking work has been focused on the study of ion diffusion in various phases and interphases to improve transport properties. The fundamental challenge of ionics relates to the transport of charged mass, and as such, will always be inferior and lowly to that of the electron. In this paper we explore how the anchor of mass transport which limits ion diffusion enables ions to do what electrons cannot, create structure. This paper explores the power of ionics to enable the electrolytic formation of batteries from very simple structures and the feasibility to harness such power in formats that are not easily addressed by batteries of today. We will discuss this concept using various halide chemistries from our initial reports on iodide ion approximately a decade ago to the more challenging fluoride Ion.
New Membranes for Redox Flow Batteries Based on Heteropoly Acid-Polymer Composites
Authors: Kushner Douglas I. , Motz Andrew R , Kuo Mei-Chen , Kusoglu Ahmet , Herring Andrew M. , Weber Adam Z.
Published: February 2020

Redox flow batteries (RFBs) remain one of the most promising technologies that are actively explored for grid-scale energy storage from discontinuous power sources such as wind and solar.[1] Proliferation of RFB technology has resulted in a need for continued development and understanding of new redox couples and improved separator membranes for RFB operation, while reducing cost. Membranes employed in RFB technology are largely comprised of the perfluorosulfonic acid (PFSA) family (e.g. Nafion, Aquivion, and 3M PFSA) which own their functionality to the phase separated structure composed of ionically conductive hydrophilic domains distributed within an inert and mechanically stable hydrophobic matrix.[2] PFSA membranes are also susceptible to high crossover of redox active species, leading to parasitic losses in capacity that can only be solved by the development of highly selective separator membranes.

In this work, we report our progress in developing membranes that exhibit high selectivity by employing heteropoly acid (HPA) ion conductors that have been covalently tethered to the backbone of a polymer support. HPA-loaded membranes are promising due to the highly mobile protons associated with the HPA molecule[3] alongside the hydrophobic polymer that provides mechanical strength that is capable of preventing crossover. PFSA membranes were used as a baseline to access the quality of the newly developed HPA-loaded membranes by measuring the selectivity which involves measurement of the membrane conductivity and permeability. The HPA-loading was varied on a mass base in order to evaluate the trade-offs between increased membrane conductivity, which tends to occur with increased permeability of redox active species. Selected membranes were subjected to cell testing in a RFB based on the iron-hydrogen to gauge cell performance.

References:

Perry, M.L. and A.Z. Weber, Advanced Redox-Flow Batteries: A Perspective. Journal of the Electrochemical Society, 2016. 163(1): p. A5064-A5067.

Kusoglu, A. and A.Z. Weber, New Insights into Perfluorinated Sulfonic-Acid Ionomers. Chemical Reviews, 2017. 117(3): p. 987-1104.

Motz, A.R., et al., Heteropoly acid functionalized fluoroelastomer with outstanding chemical durability and performance for vehicular fuel cells. Energy & Environmental Science, 2018. 11(6): p. 1499-1509.

Acknowledgements:

This study was funded with support of the U.S. Department of Energy under contract number DE-AC02-05CH11231 as sub-contract under Colorado School of Mines and United Technologies Research Center.
Innate Voids of Halloysite Enabling High-Volumetric Density Anodes for Silicon/Graphite Composites
Authors: Yeom Su Jeong , Lee Cheol Min , Kang Sujin , Ryu Jungki , Lee Hyun-Wook
Published: February 2020

Silicon (Si) has been considered as a prospective anode material in lithium-ion batteries (LIBs) due to its exceptional high capacity and energy density than the commercialized carbon-based materials. However, volume expansion (~380%) caused by alloying chemistry of silicon affects the deterioration of electrodes and battery performance. To minimize these drawbacks, the fabrication of Si/graphite composite electrodes has emerged as a promising anode since graphite anodes possess less volume expansion (~10%) with a porous structure that contributes to the accommodation of the electrode level for Si expansion. It is well known that the specific capacity and cyclability would conflict in the composite anode as increasing silicon contents. With this interpretation, previous studies reported that the theoretical limit of Si contents in the composites was approximately calculated as 15% with a numerical optimization considering electrode porosity, expansion of active materials, and so on.

Considering aforementioned issues, we propose a novel method to enhance the energy density of the composite electrode by increasing the portion of Si by use of halloysite containing native voids in the structure, resulting in less volume expansion. As the production cost should be considered for practical application, we selected silicon nanotubes (SiNT) that derived from natural halloysite clay which is widely distributed in the earth crust. With facile and cost-effective synthesis process, the synthesized SiNT has less volume expansion (~200%). From the careful investigation via in-situ transmission electron microscopy, we found the optimal composition of SiNT in the silicon/graphite composites to overcome the limited volumetric density of the anodes. The physical and chemical properties, and battery performances will be discussed in detail in this presentation.
(Invited) High-Throughput Screening of Solid-State Li-Ion Conductors Using Lattice-Dynamics Descriptors
Authors: Muy Sokseiha , Shao-Horn Yang
Published: February 2020

The average vibrational frequencies of Lithium sublattice or Li-phonon band centers have been correlated with the migration barriers of Li-ion in solid-state Li-ion conductors. In this talk, we present a computational screening of ~14,000 Li-containing compounds in the Materials Project database using this lattice-dynamic descriptor to identify new promising Li-ion conductors. After pre-screening the database for structural stability, electronic conductivity and compositions, we arrived at ~1200 compounds whose phonon band centers were computed using an optimized computational approach called Quickhesswhich requires only 2 DFT calculations per compounds. In addition to newly predicted Li-ion conductors, we also discussed broad correlations between the oxidation potential as well as anion p-band centers and the anion-phonon band centers, whose origin can be understood in term of covalency/ionicity of the cation-anion bonds in the structure. Finally, combining a low computed Li phonon-band center with the computed electrochemical stability window and the structural stability based on their energy above hull, 18 compounds were predicted to be promising Li-ion conductors. One of these newly predicted compounds, Li3ErCl6 was synthesized and was shown to exhibit a measured room-temperature conductivity of 0.3 mS/cm for the ball-milled amorphous sample and 0.05 mS/cm in the crystalline state, which further shows the promise of high-throughput search of Li-ion conductors based on lattice dynamics descriptors.
Electro-Oxidation of New Feedstocks to Value Added Chemicals
Authors: Boyd Michael James , Hahn Christopher , Jaramillo Thomas F.
Published: February 2020

Today a large fraction of plastics and other material products come from the refinement of fossil fuels. With the potential volatility in fossil fuel availability in the future there is a need for alternative sustainable means of producing the products we use on a daily basis. Electrochemical oxidation of biomass/biomass-derivatives to value-added products is one such alternative, and can be coupled with renewable energy to reduce its carbon footprint.

In the present work we explore the electro oxidation of several unconventional electrochemical feedstocks: benzyl alcohol, glycerol, and methane. The activity of ionic materials (e.g. transition metal oxides, sulfides, phosphides) for the previously mentioned reactions is investigated and compared to that of platinum and gold. XPS and XRD are used to determine the phase and oxidation state of these ionic materials to elucidate the active site for said reactions. Meanwhile NMR is used for the detection and quantification of liquid phase products as a function of electrolyte pH, applied potential, and time to determine catalyst activity and selectivity.
Electro-Oxidation of Furans to Value-Added Chemicals
Authors: Roman Alex , Hasse Joseph , Medlin Will , Holewinski Adam
Published: February 2020

Aqueous electrochemistry presents a unique platform for the valorization of biomass-derived oxygenates through rearrangements involving H or O atoms under ambient conditions. In addition, the electrochemical environment can alter product distributions and efficiencies in comparison to analogous thermochemical routes. For example, oxidation product selectivities can vary with potential by changing the surface coverage of hydroxyl groups and/or through the stabilization of products requiring electron transfer as opposed to neutral atom transfer steps.

This study focuses on characterizing the partial electro-oxidation of furfural and HMF under acidic conditions on various noble metal catalysts. These biomass-derived model compounds are derived from the acid-catalyzed conversion of lignocellulosic feedstocks and can yield value-added products such as furoic acid,maleic acid, and furan-dicarboxylic acid. A differential “flow-through” electrochemical reactor was paired with membrane-inlet mass spectrometry (MIMS) and LC-MS. We analyze the partial electro-oxidation of furans under a variety of conditions and discuss trends in product distributions as they pertain to possible reaction pathways. Ongoing work involves investigation of the reaction mechanisms through isotopic labeling experiments and electrochemical ATR-FTIR.
Electrocatalytic Hydrogenation and Oxidation of 5-Hydroxymethylfurfural for Efficient Production of Biobased Monomers: A Paired Electrolyzer Approach
Authors: Chadderdon Xiaotong , Chadderdon David J , Li Wenzhen
Published: February 2020

Electrochemical conversion of biorenewable compounds is a promising route for sustainable chemical production. Herein, we report a high efficiency for electrocatalytic conversion of 5-(hydroxymethyl)furfural (HMF) to two biobased monomers by pairing HMF reduction and oxidation reactions in a single electrochemical cell. HMF hydrogenation to 2,5-bis(hydroxymethyl)furan (BHMF) was achieved under mild electrolyte conditions (pH 9.2) over a Ag/C catalyst at the cathode. The selectivity and efficiency for Ag-catalyzed BHMF formation were sensitive to cathode potential, owing to competition from HMF hydrodimerization reactions and hydrogen evolution. Moreover, the carbon support of Ag/C was active for HMF reduction and contributed to undesired dimer formation at strong cathodic potentials. As a result, high BHMF selectivity and efficiency was only achieved within a narrow potential range near –1.3 V. At the anode, HMF oxidation to 2,5-furandicarboxylic acid (FDCA) with ~100% efficiency was achieved under the same conditions by a homogeneous redox mediator, 4-acetamido-TEMPO (ACT), together with an inexpensive carbon felt anode. Furtunately, the insensitive selectivity of ACT-mediated HMF oxidation anode potential allows HMF hydrogenation and oxidation reactions to perform together in a single electrochemical cell, which demonstrates high molar yields of BHMF and FDCA (86% and 96%, respectively) and a combined electron efficiency of 187%, which is nearly two-fold enhancement compared to the unpaired cells. Our recent progress in developing porous Ag electrode materials for electrochemical reduction will also be presented.
Electrocatalytic Hydrogenation of Lignocellulosic Biomass to Hydrocarbon Fuels: Life Cycle Assessment and Technoeconomic Analysis
Authors: Das Sabyasachi , Saffron Christopher M.
Published: February 2020

According to the 2016 Billion Ton Report, the annual harvestable biomass in the U.S. (that can be produced at $60/ton or less) by the year 2030 is not sufficient to meet the annual energy demands of the U.S. transportation sector alone. Therefore, for biomass-derived fuels to be considered a realistic alternative to fossil fuels, processes must be developed to upgrade the energy content of these biofuels to match that of petroleum-based fuels. Such energy upgrading must also overcome the barriers resulting from biomass’ dispersed nature and the high costs of transporting a low bulk density feedstock. Depot-based fast pyrolysis partially overcomes these barriers by densifying biomass into bio-oil, however this mixture is reactively unstable and corrosive. Subsequent electrocatalytic hydrogenation (ECH) potentially stabilizes this bio-oil to a form that can be transported and stored at a centralized refinery. ECH involves using mild temperature, atmospheric pressures and renewable electricity, such as wind or solar, to split water on a catalytic cathode to produce in situ hydrogen and consequently perform the reduction of reactive aromatic compounds present in bio-oil. For the bioenergy system studied, the catalytic cathode was selected to be ruthenium on activated carbon cloth with a platinum anode. Bio-oil was modelled as a mixture of eight compounds, each species representing a key functional group. To investigate the merits of this biofuel production strategy, mass, energy and carbon flow analyses were performed for the proposed system. These were compared to the traditional approach of cellulosic ethanol fermentations as described in a 2011 report by NREL. The comparative study revealed the advantages of the proposed process in terms of mass, carbon, and energy efficiency. More recently, a full scale “cradle-to-grave” life cycle assessment (LCA) was performed to quantify the environmental impacts of the proposed process, such as global warming, eutrophication, and water use. As suspected, the LCA analyses revealed that the electrical power source plays a major role in determining the overall climate change potential of systems that upgrade biomass using electrocatalytic hydrogenation. A full-scale economic analysis was also performed to estimate the minimum fuel selling price (MFSP) and to elucidate the most sensitive parameters affecting the MFSP. The LCA and the techno-economic analysis are integral steps in the commercial application of the proposed bioenergy system.
Tailoring Color and Surface Morphology of Electrodeposited Chromium By Application of Pulsed Current
Authors: Leimbach Martin , Tschaar Christoph , Zapf David , Kurniawan Mario , Schmidt Udo , Bund Andreas
Published: February 2020

The electrodeposition of chromium layers for decorative purposes plays an important role in the surface finishing industry, especially for applications in sanitary, automotive, plating on plastics and similar fields. As the use of conventional hexavalent chromium based electrolytes is strongly restricted in several countries,1 the demand for alternative plating systems increased during the last years. The most promising alternative is the electrodeposition from trivalent chromium based electrolytes considering environmental safety, quality of the deposits and cost issues.2 Commercially applicable processes are already known since several decades.3 However, trivalent chromium based processes cannot fully meet the requirements on surface appearance of the layers.4 This is crucial for the above mentioned applications as slight differences in color can have a high impact on final implementation of the plated parts.

In this work chromium layers plated from different electrolytes were characterized by colorimetry, SEM and AFM. A relation between optical appearance and surface morphology was found and supported by a model based on the theory of light scattering on rough surfaces.5 In case of chromium(III) sulfate based electrolytes, grain size and roughness increase with increasing layer thickness, leading to a color shift from blueish to yellowish. To achieve a blueish appearance while having sufficient resistance against corrosion and wear, a fine-grained surface structure has to be obtained at high layer thickness. By application of pulsed cathodic current, grain growth is suppressed and nucleation is re-initiated at each current pulse, giving a surface grain size of 60 to 100 nm. Up to a chromium thickness of 200 nm, the color value still in the blueish range (b* < 0 in the L*a*b* color system). However, special characteristics of chromium electrodeposition from trivalent solutions have to be considered for choosing suitable pulse parameters in large scale applications.

European Chemicals Agency, Authorisation List, EC No. 215-607-8, 231-801-5, 231-889-5, 231-906-6, 232-140-5, 232-143-1, 234-190-3, 236-881-5.

Z. X. Zeng, A. M. Liang, and J. Y. Zhang, Recent Pat. Mater. Sci.,
2 (1), 50 (2009).

S. L. Handy, C. F. Oduoza, and T. Pearson, Trans. IMF,
84 (6), 300 (2006).

D. L. Snyder, Plat. Surf. Finish.,
90 (11), 34 (2003).

M. Leimbach, C. Tschaar, D. Zapf, M. Kurniawan, U. Schmidt, and A. Bund, J. Electrochem.
Soc.,
166 (6), D205 (2019).
Segregation in Aluminum-Zirconium Alloys, Electrodeposited from Ionic Liquids, and Its Modification By Pulse Plating
Authors: Freydina Evgeniya
Published: February 2020

It is quite typical for aluminum-zirconium alloys, obtained by electrodeposition in chloroaluminate ionic liquids, to have two or more distinct phases with different Zr concentrations. The Zr content in one phase can be several times higher than in the other. In the present work we have studied this segregation in [EMIM]Cl*AlCl3 ionic liquid. Factors like temperature, current density, agitation, and concentrations of both zirconium and aluminum in the electrolyte were investigated.

A proposed mechanism for this phenomenon is based on a possibility of two different pathways of zirconium reduction. One pathway is a 4-electron process, taking Zr4+ directly to metal. Another way is a 2-electron reaction via intermediate Zr2+ ions formed in the solution. The difference between these pathways includes variations in chloride ions concentration in the vicinity of the electrode surface, as well as variations in charge and structure of the double layer.

The above variations exist only near the cathode surface, and have a limited life time. One approach to eliminating the segregation in the alloy is to utilize pulsed electrodeposition methods, allowing re-mixing and equilibration of the electrolyte during the off periods. As expected, shorter pulses and longer off times lead to more compositionally uniform deposits.

Figure 1. Backscatter SEM image of a cross section of Al-Zr deposit. Light areas are zirconium-rich.

Figure 1
Direct Electrocatalytic Conversion of CO2 to Chemicals over Single Atom Catalysts
Authors: Liu Di-Jia
Published: February 2020

Carbon dioxide emission from fossil fuel combustion has generated an on-going debate on its impact to the global environmental and ecological systems. New carbon capture, sequestration and conversion technologies are widely pursued as potential solutions to mitigate the concerns. The electrochemical CO2 reduction reaction (CO2RR) to hydrocarbon fuels and chemicals using renewable electricity offers an attractive “carbon-neutral” or even “carbon-negative” mitigation strategy. CO2 is an inexpensive carbon source and can be used as a feedstock for producing high value chemicals. Key challenges facing the current CO2RR electrocatalysis include: a) how to improve energy efficiency by reducing the overpotentials; b) how to increase the process selectivity by enhancing a single-product Faradaic efficiency (FE); and c) how to lower the system operating cost by prolonging the catalyst stability.

Argonne National Laboratory through collaboration with Northern Illinois University recently developed a series of highly active and durable single atom catalysts (SACs) for CO2RR prepared using a robust synthesis method over the commercial carbon support. The new electrocatalysts offer the several advantages including: a) direct conversion to C2 (C2H5OH and CH3CO2H) and C3 (C3H6O) chemicals in one-step electro-catalytic reaction without secondary upgrading; b) higher than 90% FE by suppressing the byproduct formation; c) high energy efficiency with the onset potential as low as 0.4 V observed for ethanol conversion; and d) good stability with no sign of activity loss during extended hours of chronoamperometry measurement.

In this presentation, we will discuss the structure-function relationship of the new SACs with particular emphasis on CO2 to ethanol conversion. We will also share the mechanistic insight on catalysis as the catalyst transitioning from SAC to metal cluster. The catalyst performance in terms of FE, onset potential and durability will also be reported, combined with the catalyst structural properties obtained from various conventional and advanced characterization tools.

Acknowledgement: The work performed at Argonne National Laboratory is supported by Office of Science, U.S. Department of Energy under Contract DE-AC02-06CH11357.
Ion-Implanted Photoresist Stripping by Using Organic Solvents
Authors: Oh Eunseok , Lim Sangwoo
Published: February 2020

In the ion implantation process, accelerated ions attack not only target materials but also photoresist, causing deformation of the molecular structure of the photoresist. It is difficult to remove crust layer formed by ion implantation in the standard photoresist removal methods. A typical method of removing high-dose ion-implanted photoresist is to use plasma ashing followed by the treatment in the mixture of hot sulfuric acid and hydrogen peroxide [1]. However, this process etches III-V semiconductors and dielectric materials [2]. Therefore, in this study, organic solvent-based mixtures were developed to remove high-dose ion-implanted photoresist without damaging the substrate.

Trench-patterned GaAs was used as a substrate and KrF photoresist was coated on trench patterned GaAs. Then, P+ ion implantation with a dose of 5×1015 ions/cm2 was conducted on the photoresist. A mixed solution of dimethyl sulfoxide (DMSO) and acetonitrile (AcN) (DMSO: AcN = 6: 4) was used to remove the ion-implanted photoresist and 1 vol% HCl or HF was used as an additive. Photoresist removal was measured using an optical microscope and in-situ MIR-FTIR.

When a mixed solvent of DMSO and AcN was used to remove ion-implanted photoresist, the photoresist was not completely removed and the residue and crust remained on the trench-pattern (Fig. 1). In order to improve the removal efficiency of ion-implanted photoresist, 1 % HCl or HF was added to DMSO+AcN solution. When 1 % HCl was added to the DMSO+AcN solution, the ion-implanted photoresist with an implantation energy of 30 and 50 keV was completely removed without residue. However, when the ion implantation energy was 70 keV, the photoresist crust was not removed in DMSO+AcN+HCl solution. When 1 % HF was added to DMSO+AcN solution, the ion-implanted photoresists was completely removed regardless of the ion implantation energy. Removal performance was quantitatively analyzed by in-situ MIR-FTIR as shown in Fig. 2. First, the ion-implanted photoresist was not removed more than 40 % for 10 min in DMSO. In DMSO+AcN solution, most of the photoresist was removed in 6 min, and all photoresist was removed in 4 min when DMSO+AcN+HCl was used. In the case of DMSO+AcN+HF, all of the ion-implanted photoresists were completely removed in 2 min and 30 s. Therefore, it is confirmed that DMSO+AcN+HF solution removes ion-implanted photoresist more quickly and effectively than other solutions used in this study. In addition, it is suggested that the largest interaction energy between DMSO+AcN+HF and the ion-implanted photoresist resulted in improvement of the removal efficiency of the photoresist.

References

[1] K. Kinoshita and P. Engesser, ECS J. Solid. State. Sc., 2, Q34 (2013).

[2] O. Louveau, D. Louis, M. Assous, R. Blanc, P. Brun, S. Lamy and E. Lajoinie, Microelectron. Eng., 61–62, 867 (2002).

Figure 1
Vapor Phase Infiltration of Metal Oxides into Nanoporous Polymer Membranes for Organic Solvent Separation
Authors: McGuinness Emily Kathryn , Zhang Fengyi , Ma Yao , Lively Ryan P. , Losego Mark D.
Published: February 2020

Membrane-based organic solvent separations promise a low-energy alternative to traditional thermal separations but require advanced materials that operate reliably in chemically aggressive environments. While inorganic membranes can withstand demanding conditions, they are costly and difficult to scale. Polymeric membranes, such as polymers of intrinsic microporosity, are easily manufactured into form factors consistent with large-scale separations (e.g., hollow fibers), but perform poorly in aggressive solvents. Here, a new post-fabrication membrane modification technique, vapor phase infiltration (VPI) is reported that infuses polymer of intrinsic microporosity 1 (PIM-1) with inorganic constituents to improve stability while generally maintaining the polymer’s macroscale form factor and microporous internal structure (Figure 1). The atomic-scale metal oxide networks within these hybrid membranes protect PIM-1 from swelling or dissolving in organic solvents including: tetrahydrofuran, dichloromethane, and chloroform (Figure 2a). This atomic-scale metal oxide network further decreases the molecular weight cutoff (MWCO; the smallest molecular weight the membrane “successfully” rejects) in n-heptane and toluene from a MWCO of about 600 g/mol for pristine PIM-1 thin film composite membranes to 204 g/mol for hybrid AlOx/PIM-1 membranes (Figure 2b). The hybrid membranes further retain this MWCO and high levels of rejection (>95%) in solvents that traditionally swell or even dissolve pristine PIM-1 (such as ethanol and tetrahydrofuran). The decrease in MWCO and increase in stability of AlOx/PIM-1 hybrid membranes allows them to perform separations not only between solutes and solvents, but also separations of more challenging systems such as those comprising multiple solvents. For example, the hybrid AlOx/PIM-1 membranes are capable of enriching the toluene concentration in a mixture of 90 wt% toluene, 5 wt% 1,3,5-triisopropylbenzene, and 5 wt% 1,3-diisopropylbenzene from 90.0 wt% to 97.8 ± 0.3 wt%. In this talk, we will discuss the chemical mechanisms of the infiltration process that we believe create the hybrid structures necessary to support this enhanced stability and separation performance.

Figure 1
(Invited) Challenges and Opportunities for Selective Area Processing in High Volume Manufacturing (HVM)
Authors: Sharma Kashish , Lemaire Paul , Nardi Katie , Hausmann Dennis
Published: February 2020

In the recent years scaling approach to Moore’s law has slowed, there is longing for innovations in processes, design, tools, and materials. Selective deposition is one of them which has been used in various forms, most communally, metals on metals in the semiconductor industry. More advanced forms of selective area process such as metals on dielectrics, dielectrics on metals and dielectrics on dielectrics are making some progress at the industrial level for integration at HVM level. Since it has the potential to reduce the number of lithographic and etch steps in the manufacturing flow, it has been pursued actively at academic as well as at an industrial level.

In this talk, we will explore the selective processing applications which are driving the driving the semiconductor industry to look beyond conventional top-down processing. Applications where selective deposition are needed will be discussed. We will then look at the bottlenecks which needs to be addressed for selective processing technique to become a high volume manufacturable (HVM) process. The challenges and opportunities for HVM will be presented with an emphasis on the need for low defectivity, low cost, high throughput, repeatable, processes that can be applied across a 300 mm wafer without the loss of unit film properties. We will discuss some approaches that Lam Research is taking to meet these requirements, and also where innovation is still needed. Through this presentation, we hope to bring synergy and accelerate innovation in HVM-compatible selective processing.
Growth Kinetics of Magnesium Silicide Formation Via Reaction of Mg Gas and Si Substrates
Authors: Li Jiaqi , Sandhage Kenneth
Published: February 2020

The thermal, electrical, optical, and chemical properties of magnesium silicide (Mg2Si) have led to consideration of this semiconducting material for use in thermoelectric, optical, sensor, corrosion mitigation, and other applications. The relative non-toxicity and earth-abundant nature of the constituent elements of this silicide are also attractive characteristics. One approach for generating patterned magnesium silicide structures for use in devices is the direct conformal reaction of patterned silicon structures with magnesium gas. The kinetic mechanism controlling such conformal gas/solid reaction will be discussed in this presentation.

The rate of thickening of magnesium silicide films, via the reaction of magnesium gas with planar silicon single crystal substrates, has been examined via measurements of mass change (∆m/A) and film thickness (∆X from SEM analyses of reacted cross-sections) as a function of time at 600oC. To avoid oxidation during such reaction, experiments were conducted within metal ampoules that had been carefully sealed in an argon atmosphere. Upon heating of the sealed ampoules to 600oC within an argon atmosphere tube furnace, magnesium gas (generated from solid magnesium within the ampoule) migrated to, and underwent reaction with, the planar silicon substrate. Measurements of ∆m/A vs. time and ∆X vs. time were both consistent with a parabolic rate law for the thickening of the Mg2Si layer, with the rate constants from both types of measurements in good agreement. Variations in the magnesium gas diffusion distance, and in the orientation of the starting silicon single crystal, were found to have negligible influence on the reaction kinetics. Such kinetic data were consistent with Mg2Si formation controlled by solid-state diffusion through the Mg2Si product layer. Inert marker experiments (using MgO particles) were used to determine the dominant interface at which new Mg2Si formed, and to evaluate the associated diffusing species controlling such formation. Kinetic analyses from this solid/gas reaction study will be compared to prior work on the formation of Mg2Si via solid-state reaction of magnesium with silicon.

Figure 1
The Effect of Electron-Phonon Interactions on Thermal Conductivity
Authors: Meng Fanchen , Ma Jinlong , Li Wu , He Jian
Published: February 2020

Thermal conductivity (κ) is a key transport parameter in the fields of thermoelectric, heat management, and other functional materials research. For a long time, it is generally accepted that phonon-phonon interactions dominate the phonon thermal conductivity in semiconductors, which are the parent compounds of thermoelectric materials. Despite the well-known effect of electron-phonon interactions on the charge carrier mobility, the same on the thermal conductivity only starts to attract attention recently. In this work, we solved the Boltzmann transport equations for phonons considering both phonon-phonon interactions and electron-phonon interactions obtained from first principles calculations. It is demonstrated that electron-phonon interactions could also have a pronounced effect on the phonon transport properties, especially when the carrier concentration is large. A case study is given in Mg-based thermoelectric materials.
Investigation of Electrochemical Mechanisms in Redox-Active Polymer Thin-Films
Authors: Wyatt Quinton , Young Matthias J
Published: February 2020

Thin-film redox-active polymers, such as polyaniline and polythiophene, exhibit high rate energy storage, and have recently been demonstrated for their utility in electrochemical desalination. In order to improve the effectiveness of redox-active polymer films for electrochemical desalination, we need to understand the fundamental electrochemical mechanisms occurring in these materials. In particular, we are interested in understanding how the deposition technique impacts the polymer structure and in turn the type and quantity of ions binding to the film under applied potential in aqueous solutions. Furthermore, investigating the influence of thickness of these polymer films can further the understanding of their electrochemical mechanisms and rate capabilities. Here, we deposit thin-film redox-active polymers using nitrogen and sulfur heterocyclic monomers, and demonstrate control over the polymer film thickness from 1 – 20 nm by tuning the deposition parameters. We characterize rate capability of charge storage of the polymer films over this thickness range, and employ a range of characterization techniques, including electrochemical quartz crystal microbalance (EQCM), to study the fundamental electrochemical mechanisms at play in aqueous solutions. Mechanistic and performance studies are carried out in aqueous solutions containing various cations (e.g. Li+, Na+, K+) and anions (e.g. SO4
2-, Cl-, Br-). The insights from this study will help to inform the development of thin-film polymers for enhanced electrochemical desalination.

Figure 1
Edge Planes Oriented Electrochemically Exfoliated HOPG for Electrochemical Capacitors
Authors: Tamgadge Rupesh M , Shukla Anupam
Published: February 2020

Increase in demand of flexible and portable electronic gadgets, created a market for similar energy storage devices. Freestanding, binder free electrode is the primary component to make such an energy storage device. Graphene, a 2D form of carbon has attracted much attention as an electrode material for supercapacitor applications, because of its properties, like, high surface area and excellent intrinsic electrical conductivity. Scalable, economical synthesis of graphene and its application as an electrode material is still in the development stage. Restacking and aggregation of graphene sheets during electrode fabrication decreases effective surface area for double layer formation. Electrochemical exfoliation of HOPG leads to growth of edge oriented graphene sheets on the surface of HOPG. Controlled electrochemical exfoliation of HOPG electrodes in different electrolytes shows different capacitive performance. This performance variation is related to pH of electrolyte. A maximum aerial capacitance of 760 mF cm-2 at current density of 1 mA cm-2 achieved in electrode exfoliated in 1 M H2SO4 electrolyte.
Electrochemical Studies of One-Pot Synthesized Tetragonal Hausmannite Manganese Oxide/ Nitrogen-Doped Reduced Graphene Oxide Nanohybrid for Supercapacitor Applications
Authors: Makgopa Katlego , Ratsoma Mpho Sofnee
Published: February 2020

The increasing consumption of fossils fuel accompanied by related carbon emissions and complex set of issues associated with the generation and use of electricity has raised an urgent need for reliable, renewable and sustainable energy alternatives [1]. Remarkable progress made in nanoscience and nanotechnology brought inspiration for further development of new technologies in electrochemical energy storage. Supercapacitors (SCs) have emerged as a fast-rising class of energy storage technology and have received tremendous attention for potential applications in high-power sources [1,2]. Thus, manipulation of nanostructured materials became an important approach for the improvement of energy storage properties in SCs. Up to now, various synthetic methods have been established to improve the electrode materials for SC applications. Carbon nanomaterials such as carbon nanotubes (CNTs), graphene and graphene oxide (GO) have been widely used and modified to enhance their energy storage performance in SCs. Recently, much interest has been devoted to the doping of carbon materials to improve the performance of SC devices. Manganese oxide-based electrode materials characterized by their high theoretical specific surface area (1370 m2 g-1), high theoretical specific capacitance (1100 to 1300 F g-1), low-cost, abundance and environmentally friendly in nature, have attracted significant interest as active electrode materials for SCs. Although intensive study has been done on the MnO2-based pseudocapacitor, tetragonal hausmannite manganese oxide, Mn3O4, has received limited attention in SCs application [3]. Among various synthetic methods of synthesizing carbon/metal oxides nanohybrids, hydrothermal reduction of metal salts in the presence of carbon material is widely used, due to the simple operation and the low cost.

This work present, one-pot synthesis of nitrogen-doped reduced graphene oxide decorated with hausmannite manganese oxide (N-rGO/Mn3O4 nanohybrid) and the study of its electrochemical energy storage performance for supercapacitor application. The microscopic and spectroscopic characterization of N-rGO/Mn3O4 nanohybrid and its precursor materials were acquired using SEM, EDX, Raman and XRD whereas the electrochemical characterization were acquired using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS).
Decoration of Vanadium Pentoxide on Conductive Carbon Nanotube Framework As Electroactive Materials for Aqueous Supercapacitors
Authors: Lin Jeng-Yu , Lin Shih-Yu
Published: February 2020

Supercapacitors (SCs) have been regarded as energy-storage devices that performance between conventional capacitors and batteries. They commonly have higher energy densities, deliver higher power densities, long cycling life and faster charge/discharge rates than conventional batteries. The charge storage mechanisms of SCs are generally divided into the following two types. The one is electric double-layer capacitors (EDLCs) which originates from the charge accumulation process at the electrode/electrolyte interface, and the other type is pseudocapacitors in which the charge storage mechanisms occurs through the faradic redox reactions.

Among the transition-metal oxides, vanadium pentoxide (V2O5) has layered structure, the satisfactory charge storage capacity, a modest electronic conductivity, unique advantages of high energy density and wide potential window arising from its various vanadium oxidation states. In this work, we successfully decorated V2O5 thin layer on the surface of conductive carbon nanotubes (CNTs), designated as CNT@V2O5, by using pulsed-mode electrodeposition. It was found that the as-deposited V2O5 thin film is with nano-crystalline nature and the surface of the CNTs is evenly deposited with it. The as-deposited CNT@V2O5 electrode can reveal an enhanced discharge capacitance of 198 F/g at current density of 1 A/g in 2 M NaNO3 aqueous electrolyte.
MnCo Layered Double Hydroxide Based Pseudocapacitor: Effect of Morphology and Electrochemical Cycling
Authors: Patil Dipali S. , Ryu Jongwon , Pawar Sachin A. , Shin Jae Cheol , Kim Hyo Jin
Published: February 2020

Layered double hydroxides (LDHs) attract considerable attention for use in supercapacitors owing to their unique features such as good anion exchange abilities, high redox activities, easily tunable chemical compositions, high chemical stabilities, and large surface areas. Among the LDHs, MnCo-LDH, CoAl-LDH, and NiMn-LDH are very promising electrode materials for supercapacitors as a class of two-dimensional metal hydroxides. MnCo-LDH is the most desirable electrode material for energy storage applications in the LDH class, as cobalt can be introduced in the LDH to improve the conductivity of the electrode material; Co2+ can be oxidized to the conductive CoOOH during the electrochemical reactions. Similarly, the introduction of manganese helps improve the electrochemical activity owing to its multiple oxidation states.

We report a stepwise morphological evolution of MnCo-layered double hydroxide (LDH) cubes with the hydrothermal reaction time. The electrochemical performance of the fabricated electrode at each step was studied in detail. The obtained MnCo-LDH exhibited maximum areal capacitances of 3.17 Fcm-2 (at a scan rate of 5 mVs-1) and 3.78 Fcm-2 (at an applied current of 3 mA), good rate capability (74% at a scan rate of 100 mVs-1), and excellent energy efficiency (80% at an applied current of 4.5 mA). The electrochemical performances of all synthesized electrodes were enhanced during the electrochemical cycling, which led to morphological modifications. In addition, for practical applications, we fabricated a symmetric supercapacitor based on the MnCo-LDH electrode and studied its electrochemical performance in detail.

Keywords: MnCo, Layered double hydroxide, electrochemical cycling, pseudo-capacitor, hydrothermal.
Porous Carbon Derived from Salacca Peel Synthesized Under Hydrothermal Condition Followed By Microwave Assisted Chemical Activation As Lithium Ion Capacitor’s Electrode
Authors: Susanti Ratna Frida , Kristianto Hans , Arie Arenst Andreas , Devianto Hary
Published: February 2020

Porous carbonaceous materials have been utilized in a wide variety of high performance energy storage, i.e. as an electrode for batteries and supercapacitors. It has advantageous such as simple synthetic process and abundant raw material, excellent conductivity, outstanding physical and chemical stability in strong acid and base electrolyte etc. The waste biomass should be the best candidate for porous carbon in term of availability and price. In addition, it is also viewed as a veritable way of combating waste disposal problem in the agricultural industries. Salacca peel is a good candidate for biomass precursor since it is abundant in quantity and is not utilized properly. The hydrothermal condition (225 oC, 5 hr, 50 bar) was utilized to carbonized salacca peel into hydrochar in the presence and absence of ceria catalyst. Hydrochar was activated using microwave assisted chemical activation with potassium hydroxide (KOH) as an activated agent. The obtained carbon materials were characterized using scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and the performance of the material in Li half-cell system was evaluated by cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS). The results show that BET surface area as well as specific capacitance of porous carbon synthesized in the presence of catalyst was much higher compare to that of commercial as well as without catalyst.