bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluidic Force Microscope for Electrochemical Additive Manifacturing of Metal Microstructures
Authors: Zambelli Tomaso , Hirt Luca , Vörös János 
Published: February 2020

FluidFM is a force-controlled nanopipette [1], combining AFM technology and microfluidics. A fluidic channel is incorporated directly in a hollow AFM cantilever. This channel ends in a nanosized aperture at the apex of the AFM pyramidal tip, allowing for local dispensing of soluble molecules in air and in liquid, while retaining the inherent imaging capabilities and force feedback of an AFM system.
Recently, we have achieved 2D electrochemical patterning with sub-micron precision by reduction of copper as well as diazonium salts filled in the microchannel with subsequent in-situ AFM imaging [2]. Furthermore, we recognized that this method offered an access to the 3rd dimension.
Micro- and nanometer-scale patterning of functional materials is of great interest in various fields such as microelectronics or micro-electromechanical systems (MEMS) design [3], but also for biosensing and biomedical applications, where manipulation techniques often have to be suitable for use in a liquid environment. In this context, we currently explore the use of FluidFM as a tool for both fabrication and subsequent imaging of microstructures in liquid using the same probe.
Indeed, we succeeded in using the system in the same configuration for 3D additive manufacturing of copper on the micrometer scale [4]. In the proposed protocol, we take advantage of the FluidFM probes as a local source of Cu2+ in a macro electrochemical cell. The nanopipette is approached to the working electrode and metal ions are provided by inducing a liquid flow. Thus, metal can be reduced locally under the FluidFM probe. Conveniently, the inherent force sensing capability of the cantilever provides a means to automate this process: Whenever the growing metal deposit touches the cantilever, the cantilever bends, and its deflection is registered so that the probe may be positioned to the next place, where the process continues. Therefore, our protocol enables true voxel-by-voxel (i.e. layer-by-layer) printing with consequent almost complete geometry freedom (see the three interwined helixes).
Upon introducing the microprinting protocol with copper, we discuss our current efforts to adapt it to other metals.
[1] A. Meister et al. (T. Zambelli), Nano Lett.
2009
9:2501
[2] L. Hirt et al. (T. Zambelli), RSC Adv.
2015
5:84517
[3] L. Hirt et al. (T. Zambelli), Adv. Mater.
2016
DOI: 10.1002/adma201604211
[4] L. Hirt et al. (T. Zambelli), Adv. Mater.
2016
28:2311

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(Invited) Study on Electro-Polishing of Nb Surface By Periodic Reverse Current Method with Sodium Hydroxide Solution for Particle Accelerator Application
Authors: Saeki Takayuki , Hayano Hitoshi , Taguchi Junji , Reece Charlie E , Tian Hui 
Published: February 2020

Superconducting Radio-Frequency (SRF) cavities are used to accelerate particles in particle accelerators. In this application, the cavity is made of niobium (Nb) material and the inner surface of cavity should be polished so as to obtain the high performance of particle accelerator. The Electro-Polishing (EP) process is one of the best methods to polish the inner-surface of Nb cavity where the electrolyte is the mixture of sulfuric and hydrofluoric acids. However, this EP electrolyte is very dangerous in the operation and thus the operators need rigorous protection. Furthermore, all parts of instrument for the EP process must be made of high density polyethylene or fluorocarbon resin because the corrosion of metal occurs by hydrofluoric acid. These are the reasons why the cost of EP process becomes very expensive. In addition, the EP process produces sulfur compound on the Nb surface as a by-product. This sulfur compound can be the sources of field-emission on the inner surface of cavity and degrades the accelerating performance. In this article, we report a novel EP method using periodic reverse current and sodium hydroxide solution. The reaction produces no sulfur content and the instrument is less expensive because it is made of usual plastic material. As the result of experiments with Nb-coupon samples, we found that the surface roughness is equivalent to the conventional EP method. And some experiments with a Nb single-cell cavity will be reported.
(Invited) Chiroplasmonic and Chiroexcitonic Assemblies of Nanoparticles
Authors: Kotov Nicholas , Feng Wenchun 
Published: February 2020

Chiral inorganic nanostructures discovered over the last two decades include individual nanoparticles (NPs), their assemblies in dispersions and surfaces, as well as 2D/3D lithographic patterns. For many of them exceptionally strong polarization rotation was observed. In this talk, I will address, the (1) origin of enhanced polarization rotation; (2) methods of enantioselective assembly of nanostructures; and (3) their fundamental relevance to life homochirality on Earth, Special effort will be placed on the translation of enhanced chiroptical properties of plasmonic and excitonic NPs to applications. It will be exemplified by the bioanalytical applications for detection of DNA oligomers using CD spectroscopy that enables 1-3 order of magnitude improvement of detection of protein, DNA oligomers, and small chiral molecules. Other technological applications in chiral catalysis and polarization-based optical devices. Should time permit, recent data on the preparation and properties of chiral graphene quantum dots and chiral ceramic nanoparticles relevant to the chiroplasmonc and chiroexcitonic technologies will be presented.

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(Invited) Dynamic Bandgap Engineering in 2D Materials for Beyond Boltzmann Devices
Authors: Das Saptarshi 
Published: February 2020

In this talk I will discuss a disruptive device concept based on dynamic bandgap engineering in two dimensional layered seminconductors in order to achieve sub-60mV/decade subthrshold swing [1].
This device is refer to as two-dimensional electrostrictive field effect transistor or 2D-EFET and it works on the principle of voltage induced stress transduction. It uses an electrostrictive material as gate insulator which expands when a gate bias is applied and thereby transduces an out-of-plane stress on the 2D semiconducting channel. The stress decreases the inter-layer distance between the consecutive layers of the 2D material and dynamically reduces its bandgap. Thus the device operates with a large bandgap in the OFF state and a small or zero bandgap in the ON state. As a consequence of this transduction mechanism, internal voltage amplification takes place which results in sub-60mV/decade subthreshold swing (SS).

1. Das, S. "Two Dimensional Electrostrictive Field Effect Transistor (2D-EFET): A sub-60mV/decade Steep Slope Device with High ON current", Scientific Reports 2016,
6 (34811).
Slurry-Processed Glass-Ceramic LI2S-P2S5-LiI Electrolyte for All-Solid-State Li-Ion Batteries
Authors: Choi Seon-joo , Lee Sang-hun , Yu Ji-hyun , Doh Chil-Hoon , Ha Yoon-Cheol 
Published: February 2020

Lithium-ion batteries (LIBs) have widely been used as power sources for from small electronic devices to large-scale systems such as electric and plug-in hybrid electric vehicles, mostly due to their high power and high energy density. However, the organic electrolyte in commercial LIBs has evoked safety issues, making all-solid-state LIBs with inorganic solid electrolyte an alternative of conventional organic electrolyte batteries. Solid electrolytes are not only safer and more reliable than liquid electrolytes in thermochemical point of view but also more compatible with Li metal anode and high voltage cathode materials. Among solid electrolytes, sulfide-based electrolytes have received great attention because of their high lithium ion conductivities of 10-4 to 10-2 S cm-1 at room temperature, comparable to organic electrolytes. In most studies, however, the solid electrolytes were pressed into a pellet under extremely high pressure to increase the ionic conductivity by minimizing the void and interface between electrolyte particles. This method is not suitable for the practical cell fabrication considering the scale-up manufacture. Moreover, although the electrochemical stability of sulfide-based solid electrolytes with cathode materials was improved by an interphase coating such as LiNbO3, the stability with the anode, especially with Li metal, has not been fully studied yet, mostly reporting a short-term stability evaluated by cyclic voltammetry. In this study, we evaluate long-term electrochemical stabilities of sulfide-based solid electrolytes, LGPS (Li10GeP2S12), LPS (Li7P3S11), and LPSI (Li2S-P2S5-LiI glass-ceramic and Li7P2S8I) with respect to Li metal. Area specific interfacial resistances of the solid electrolytes were characterized by using a DC cycling method, i.e., a repeated long-term charge/discharge over 100 hours with the current density of 0.1 mA/cm2 and the duty cycle of 1 hour. Then, we demonstrate a slurry-processed all-solid-state cell with Li metal anode, LPSI glass-ceramic electrolyte, and a composite cathode, where a mixture of LiNbO3-coated LiNi0.6Mn0.2Co0.2O2, LPSI solid electrolyte, carbon black, and binder dissolved in an appropriate solvent was slurry-coated and, after drying and pressing, LPSI electrolyte slurry was coated on top of the cathode layer. The cell performances of the slurry-processed all solid-state LIB cells are evaluated in comparison with pellet-type cells.
Stabilizing High-Voltage Cathode-Electrolyte Interface Using High-Voltage Additive
Authors: Pham Hieu Quang , Kwon Young-Gil , Hwang Eui-Hyung , Lee Jung-Gyu , Song Seung-Wan 
Published: February 2020

Enabling the high energy density Li-ion batteries requires the use of high-capacity cathode material such as Li-rich layered oxide cathode (xLi2MnO3·(1-x)LiMO2 (M=Mn,Ni,Co)) that can be charged to high-voltage above 4.4 V vs. Li/Li+. The development of new electrolyte components with high anodic stability above 4.4 V vs. Li/Li+ is thus the necessity of high-voltage charging of Li-rich layered oxide cathode. Our recent research results have shown that the use of high-voltage electrolyte additives is effective in charging the Li-ion cell with Li-rich layered oxide cathode above 4.6 V vs. Li/Li+ and even at elevated temperatures, which enables high-energy density Li-ion cells. Systematic surface analyses of the cathodes revealed that the formation of surface protective film by the use of high-voltage additives led to interfacial stabilization of both cathode and anode and significantly improved cycling performance, compared to the case of conventional electrolyte. In this presentation, we report the stabilization of high-voltage interface of Li-rich layered oxide cathode under a harsh condition of high charge cut-off voltage above 4.6 V vs. Li/Li+ using fluorinated carbonates as high-voltage electrolyte additives. The results of mechanistic studies of high-voltage surface film formation and composition, and interfacial stability of Li-rich layered oxide cathode using surface sensitive spectroscopy combined with electrochemical impedance spectroscopy would be discussed.
Acknowledgements: This research was supported by the Korean Ministry of Trade, Industry & Energy (R0004645) and Chungnam National University.
Solid Electrolytes for Thin Film Li-Ion Batteries with Novel Si and SiC Based Anodes
Authors: Mentbayeva Almagul , Kurmanbayeva Indira , Kulametov Zhalgas , Batyrbekuly Dauren , Umirov Nurzhan , Bakenov Zhumabay 
Published: February 2020

Recent advances in microelectromechanical systems technology have led to development of diverse small-scale devices that include microsensors, micromachines and devices for medical application. For these devices, there is an urgent need of new micro lithium-ion batteries (MLIBs) with high energy density and low cost. To avoid the leakage problems which could worsen both the operation and safety of microdevices powered powered by MLIB the use of solid electrolyte is highly desirable.
In this work, ceramic solid state and polymer solid electrolytes were prepared and deposited on the surface of SiC thin film anode by various techniques: in situ polymerization, drop coating technique, electropolymerization, magnetron spattering etc.
Despite the advantages of high capacity and low voltage of Si anode, its practical application restricted by severe volume expansion and mechanical degradation upon lithium alloying and de-alloying processes. In this term flexible thin polymer electrolyte could be a promising solution. A combination of nanoparticulate and thin film structure can provide significant mechanical stability to Si and mitigate its limitations.
Physical properties of the obtained samples were characterized by Raman spectroscopy, X-ray diffraction, atomic force microscopy and scanning/transmission electron microscopy techniques. Further, assembling CR2032 coin type cell, the electrochemical properties of the cell with obtained samples were evaluated as a part of all solid-state thin film battery.

Acknowledgements

This research was funded by the target program №0115РК03029 "NU­ Berkeley strategic initiative in warm ­dense matter, advanced materials and energy sources for 2014­-2018" from the Ministry of Education and Science of the Republic of Kazakhstan.
(Invited) Overcoming Catalytic Material Challenges for Advanced Water Splitting Technologies
Authors: Peterson David , Miller Eric L. , Randolph Katie , Vickers James 
Published: February 2020

The emergence of hydrogen and fuel cell technologies offers the world important and potentially transformative environmental and energy security benefits. In recent years, research sponsored by the US Department of Energy’s (DOE) Fuel Cell Technologies Office (FCTO) has made significant contributions to the development of these technologies. With major automotive manufacturers rolling out commercial fuel-cell electric vehicles, enabling technologies for the widespread production of affordable hydrogen are becoming increasingly important. FCTO’s Hydrogen Production Program supports a broad range of hydrogen production pathways using diverse feedstocks, ranging from nearer-term to longer term technologies. One of the more versatile pathways is based on splitting water via either electrolytic, photoelectrochemical, or thermochemical routes. For these advanced water splitting (AWS) technologies, there are tradeoffs amongst efficiency, durability, and cost at the materials, device, and system levels that need to be balanced for low cost hydrogen production. Recent advances have been made in catalytic materials for AWS to improve these attributes; however, further developments, from new materials to scale-up of state-of-the-art (SOA) materials, are required to reach large scale technoeconomic viability. Research innovations to advance the SOA in AWS materials are being facilitated by the DOE “HydroGEN” Energy Materials Network (EMN) consortium. An overview of FCTO’s Hydrogen Production Program activities with a focus on catalysts for advanced water splitting technologies and the HydroGEN consortium will be provided.
An Electrochemistry in Situ TEM Study on the Shape Evolution of Octahedral Pt-Ni Nanoparticles
Authors: Beermann Vera , Holtz Megan E , Muller David A. , Strasser Peter 
Published: February 2020

In polymer electrolyte membrane fuel cell research, shaped nanoparticles have attracted much attention in the last years. For the cathode, octahedral PtNi nanoparticles show promise in their high oxygen reduction reaction (ORR) activities due to their extended availability of (111) facets. This group of materials has been studied extensively including methods like XPS, TEM, EDX and EELS to understand their growth and degradation1-4. However, nanoscale analysis of their degradation has not been observed in real time.
Here, we present a novel in situ TEM electrochemistry study in acidic media on octahedral Pt-Ni nanoparticles synthesized via a solvo-thermal route. With real time imaging we were able to track and observe changes in the catalyst structure and particle shape during different electrochemical treatments5. For each electrochemical treatment, various potential sequences were applied in the TEM cell. We were able to confirm strong corrosive consequences on the catalyst structure and particle shape of an uncontrolled high open circuit potential (~ 1.6 V vs. RHE) after controlled electrochemical cycling. Additionally the impact on the material of stepwise increase of the upper potential (≤ 1.4 V vs. RHE) during electrochemical cycling in comparison with equivalent chronoamperometric profile was studied, showing increased degradation rates when high potentials were held. Furthermore we were able to observe the dissolution of nickel catalyst particles, even with relatively cautious electrochemical treatment (0.0 – 1.0 V vs. RHE). While electrochemical cycling up to 1.2 V vs. RHE is not harmful to the octahedral particle shape, it was still possible to observe limitations of catalyst stability by motion on the catalyst support.
Our study allows us to gain deeper insight of the real time behavior and degradation of shaped PtNi electrocatalysts, and develop understanding of the parameters that will optimize the lifetime of the catalyst.
1. Arán-Ais, R. M.; Yu, Y.; Hovden, R.; Solla-Gullón, J.; Herrero, E.; Feliu, J. M.; Abruña, H. D. Journal of the American Chemical Society
2015,137, (47), 14992-14998.
2. Choi, S.-I.; Xie, S.; Shao, M.; Odell, J. H.; Lu, N.; Peng, H.-C.; Protsailo, L.; Guerrero, S.; Park, J.; Xia, X.; Wang, J.; Kim, M. J.; Xia, Y. Nano Letters
2013,13, (7), 3420-3425.
3. Gan, L.; Cui, C.; Heggen, M.; Dionigi, F.; Rudi, S.; Strasser, P. Science
2014,346, (6216), 1502-1506.
4. Beermann, V.; Gocyla, M.; Willinger, E.; Rudi, S.; Heggen, M.; Dunin-Borkowski, R. E.; Willinger, M.-G.; Strasser, P. Nano Letters
2016, 16, (3), 1719-1725.
5. Holtz, M. E.; Yu, Y.; Gunceler, D.; Gao, J.; Sundararaman, R.; Schwarz, K. A.; Arias, T. A.; Abruña, H. D.; Muller, D. A. Nano Letters
2014, 14, (3), 1453-1459.
Interfacial Effect Study of Alkaline Membrane Media Using Microelectrodes
Authors: Malley Jenna , Doan Huong , Gunasekara Iromie , Mukerjee Sanjeev 
Published: February 2020

Interfacial issues at anion exchange membranes greatly influence the electrocatalysis at high pH environment especially in conjunction with an anion exchange membrane. In this context it is well known that carbonate ions in the context of a prototypical anion exchange membrane such as A 201 (Tokuyama, Japan) are strongly adsorbing anions and thus can suppress HOR kinetics. Not only can carbonate ions block catalyst active sites, but they can also lower the amount of hydroxyl ions for adsorption at low pH. Moreover, corresponding ionomers such as AS-4 (Tokuyama, Japan) has a negative effect on HOR activity in the context of Pt, as shown in Figure 1c. At NUCRET, we successfully concluded the effect of carbonates in conjunction of anion exchange membrane as well as the role of corresponding ionomers such as AS-4. In this study we further extend this investigation by including microelectrodes in two different media - carbonate and hydroxide - for HER (Pt microelectrode) and OER (Ir microelectrode). Hence this presentation will include the following work:
Using A 201 in hydroxide form and carbonate form in the Solid State Cell setup (Figure 1a), under the following scenarios:
1) Water fed vs. KOH vs.K2CO3 continuous feed (for electrolytes, equal conductivity and equal pH conditions);
2) HER/HOR and OER/ORR while feeding electrolyte from the top, bottom, or both.
This study is aimed at understanding the improvements observed when feeding a low concentration of carbonate at the anode interface (OER electrode) during water electropysis (Figure 1b). We hypothesize that the improvement could be because of the conductivity boost from 1% carbonate, because of different reaction mechanisms between HER (cathode side) and OER, or both. This micro-electrode study therefore is designed to not only mimic carbonate vs. hydroxide at the membrane interface via directional feed of carbonate ions (i.e., top where the microelectrode is at an interface with the membrane) or bottom to mimic mass transport and kinetics at the membrane interface. Transferring this study to the practical water splitting cell, will provide a thorough insight of the reactions between the catalyst layer and the membrane while feeding water vs. different electrolytes. It is particularly important to note that A-201 standard (Tokuyama, Japan) represents the state-of-the-art in alkaline membranes. Currently, our partner - Proton On-Site provides the full cell scale-up water splitting stack with the use of our best non-PGM catalysts for HER (60% Ni-Cr/C) and OER (40% Ni-Fe/Raney-PANI), as well as feeding 1% carbonate on the anode side.

Figure 1
Compositional Optimization of Alloy FexNiy(OH)2 Nanoparticles for Alkaline Electrochemical Oxygen Evolution
Authors: Greenlee Lauren F , Acharya Prashant , Nelson Zachary 
Published: February 2020

It has recently been demonstrated by Bell and co-authors [1] that intentional iron doping into a nickel hydroxide film causes significant enhancement in electrochemical performance for the oxygen evolution half reaction (OER) of alkaline electrolysis. A subsequent study by Boettcher and co-authors [2] demonstrated that unintentional iron doping of a nickel hydroxide catalyst occurs from ppm- to ppb-level iron contaminants in alkaline electrolytes; the iron incorporates into the nickel hydroxide structure, and causes at least an order of magnitude increase in current density. Freibel et al. subsequently demonstrated that iron may in fact be the active site of OER, with nickel hydroxide acting as a host [3]. The majority of the work thus far investigating how iron content in an FexNiy(OH)2 catalyst affects OER has been performed on thin film catalysts; Burke et al. specifically describe the need for catalyst architectures that reduce mass transport limitations and allow improved access to more active sites per unit mass of catalyst [4]. As a result, there is an interest in developing nanoscale catalysts that are composed of iron and nickel and result in greatly improved performance metrics for OER over their thin film counterparts. Here, we will present results for the optimization of a FexNiy(OH)2 nanoparticle catalyst. In this work, the nanoparticles are synthesized with an alloy morphology and the atomic ratio of iron to nickel is varied from 1:5 to 5:1. Once synthesized, the nanoparticles are evaluated in 1 M KOH that has been purified to remove any iron impurities. Electrochemical performance of this series of nanoparticle catalysts will be discussed as well as our efforts to characterize the nanoparticles with electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction.
[1] M.W. Louie, A.T. Bell, An investigation of thin-film Ni-Fe oxide catalysts for the electrochemical evolution of oxygen, J. Am. Chem. Soc., 135 (2013) 12329-12337.
[2] L. Trotochaud, S.L. Young, J.K. Ranney, S.W. Boettcher, Nickel-iron oxyhydroxide oxygen-evolution electrocatalysts: The role of intentional and incidental iron incorporation, J. Am. Chem. Soc., 136 (2014) 6744-6753.
[3] D. Friebel, M.W. Louie, M. Bajdich, K.E. Sanwald, Y. Cai, A.M. Wise, M.-J. Cheng, D. Sokaras, T.-C. Weng, R. Alonso, R.C. Davis, J.R. Bargar, J.K. Norskov, A. Nilsson, A.T. Bell, Identification of highly active Fe sites in (Ni,Fe)OOH for electrocatalytic water splitting, J. Am. Chem. Soc., 137 (2015) 1305–1313.
[4] M.S. Burke, L.J. Enman, A.S. Batchellor, S.H. Zou, S.W. Boettcher, Oxygen evolution reaction electrocatalysis on transition metal oxides and (oxy)hydroxides: Activity trends and design principles, Chemistry of Materials, 27 (2015) 7549-7558.