Name: fabrication of vb2/air cells for electrochemical testing
Uploaded: 2013-08-05T01:00:00
Description: Watch this Scientific Journal Video about Fabrication of VB2/Air Cells for Electrochemical Testing at JoVE.com

The authors would like to acknowledge the National Science Foundation Award 1006568 for funding this project.

1. Preparation Nano-VB2
Nanoscopic VB2 is directly synthesized from elemental vanadium and boron via ball-milling in a 1:2 mole ration.
<ol>
	<li>Clean a 50 ml tungsten carbide milling jar and ten 10-mm tungsten carbide balls. Dry under air in an oven at 100 &deg;C for 1 hr to ensure all water has evaporated.</li>
	<li>Wipe clean the inside of the milling jar to ensure no residue remains, repeat step 1.1 if residue is visible.</li>
	<li>Purge the antechamber of a glove ...

<ol>
	<li>Linden, D., Reddy, T. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Batteries. , (2010).</li><li>Rogulski, Z., Czerwin'ski, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cathode+Modification+in+the+Leclanche'+Cell.">Cathode Modification in the Leclanche' Cell.</a> Journal of Solid State Electrochemistry. 7, 118-121 (2003).</li><li>Neburchilov, V., Wang, H., Martin, J. J., Qu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+on+air+cathodes+for+zinc+-+air+fuel+cells.">A review on air cathodes for zinc - air fuel cells.</a> Journal of Power Sources. 195, 1271-1291 (2010).</li><li>Yu, X., Licht, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+capacity+alkaline+super-iron+boride+battery.">High capacity alkaline super-iron boride battery.</a> Electrochimica Acta. 52, 8138-8143 (2007).</li><li>Licht, S., Wang, B., Ghosh, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Energetic+Iron(VI)+Chemistry:+The+Super-Iron+Battery.">Energetic Iron(VI) Chemistry: The Super-Iron Battery.</a> Science. 285, 1039-1042 (1990).</li><li>Licht, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+aluminum+batteries:+a+step+towards+derivation+of+superbatteries.">Novel aluminum batteries: a step towards derivation of superbatteries.</a> Colloids and Surfaces A: Physicochemical and Engineering Aspects. , 134-241 (1998).</li><li>Licht, S., Myung, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorinated+Graphites+as+Energetic+Cathodes+for+Nonaqueous+Al+Batteries.">Fluorinated Graphites as Energetic Cathodes for Nonaqueous Al Batteries.</a> Electrochem. Solid-State Lett. 5, A160-A163 (2002).</li><li>Licht, S., Ghosh, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+power+BaFe(VI)O4/MnO2+composite+cathode+alkaline+super-iron+batteries.">High power BaFe(VI)O4/MnO2 composite cathode alkaline super-iron batteries.</a> Journal of Power Sources. 109, 465-468 (2002).</li><li>Licht, S., Myung, N., Peramunage, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrahigh+Specific+Power+Electrochemistry,+Exemplified+by+Al/MnO4-+and+Cd/AgO+Redox+Chemistry.">Ultrahigh Specific Power Electrochemistry, Exemplified by Al/MnO4- and Cd/AgO Redox Chemistry.</a> The Journal of Physical Chemistry B. 102, 6780-6786 (1998).</li><li>Licht, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aluminum/Sulfur+Battery+Discharge+in+the+High+Current+Domain.">Aluminum/Sulfur Battery Discharge in the High Current Domain.</a> J. Electrochem. Soc. 144, L133-L136 (1997).</li><li>Gao, X. -. P., Yang, H. -. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-electron+materials+for+high+energy+density+batteries.">Multi-electron materials for high energy density batteries.</a> Energy and Environmental Science. 3, 174-189 (2010).</li><li>Yang, H. X., Wang, Y. D., Ai, X. P., Cha, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metal+Borides:+Competitive+High+Capacity+Anode+Materials+for+Aqueous+Primary+Batteries.">Metal Borides: Competitive High Capacity Anode Materials for Aqueous Primary Batteries.</a> Electrochemical and Solid-State. 7, A212-A215 (2004).</li><li>Licht, S., Yu, X., Qu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+Alkaline+Redox+Couple:+Chemistry+of+the+Fe6+/B2-+Super-iron+Boride+Battery.">Novel Alkaline Redox Couple: Chemistry of the Fe6+/B2- Super-iron Boride Battery.</a> Chemical Communications. 2007, 2753-2755 (2007).</li><li>Licht, S., Wu, H., Yu, X., Wang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renewable+Highest+Capacity+VB2/Air+Energy+Storage.">Renewable Highest Capacity VB2/Air Energy Storage.</a> Chemical Communications. 2008, 3257-3259 (2008).</li><li>Light, S., Ghosh, S., Wang, B., Jiang, D., Asercion, J., Bergmann, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoparticle+Facilitated+Charge+Transfer+and+Voltage+of+a+High+Capacity+VB2+Anode.">Nanoparticle Facilitated Charge Transfer and Voltage of a High Capacity VB2 Anode.</a> Electrochemical and Solid-State. 14, 83-85 (2011).</li><li>Licht, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nano-VB2+Synthesis+from+Elemental+Vanadium+and+Boron:+Nano-VB2+Anode/Air+Batteries.">Nano-VB2 Synthesis from Elemental Vanadium and Boron: Nano-VB2 Anode/Air Batteries.</a> Electrochemical and Solid-State Letters. 15, A12-A14 (2012).</li></ol>

Construction of the VB2/air battery in this way provides the ability to study and probe the eleven electrons per molecule charge transfer that occurs, allowing the possibility for a new high capacity battery. If obtained results do not demonstrate reproducible results, ensure that all of the zinc anode material was removed from the battery, that there is an even dispersion of active material on the cap, and that the cells are properly glued without any leaks. If a problem continues to occur, ensure that the ba...

Vanadium diboride as an anode has among the highest volumetric charge capacity of any anode material. This protocol introduces a method for studying this fascinating material. Metallic zinc has been the predominant anode material in aqueous primary systems due to zinc metal's high two-electron volumetric and gravimetric charge storage capacities of 5.8 kAh L-1 and 820 Ah kg-1, respectively.* The zinc-carbon battery, known as the Leclanch&eacute; cell, was first introduced in the 19th century, combining a zinc anode with a manganese dioxide (carbon current collector) cathode in a chloride electrolyte1. The common alkaline battery utilizes the same couple, but replaces the chloride electrolyte with an aqueous alkali hydroxide electrolyte. Together zinc-carbon and alkaline batteries comprise the majority of primary batteries sold 1. When the manganese dioxide cathode in the alkaline cell is replaced by an air cathode, substantially higher energy storage capacities are achieved. This zinc-air battery utilizes oxygen from the air, and is commonly found in hearing-aid batteries 1-3.
Our search for higher capacity battery storage has focused on materials that can transfer multiple electrons per molecule 4-11. Among the wide variety of redox couples we have explored, VB2 stands out as an extraordinary alkaline anode capable of releasing 11 electrons per VB2, with volumetric and gravimetric capacities of 20.7 kAh L-1 and 4060 Ah kg-1 respectively.* In 2004, Yang and co-workers reported the discharge of VB2, but also documented the extended domain in which VB2 is susceptible to corrosion in alkali media 12. In 2007, we reported that a coating on the VB2 particles prevents this corrosion13, leading to demonstration of the VB2/air battery in 2008 14.
In this paper, we present a protocol used to investigate new metal/air systems employing the technology previously developed for the zinc/air cell as applied to the VB2/air cell. A nanoscopicVB2 anode is presented as a high-energy high-power density anode capable of exhibiting an eleven-electron oxidation reaction approaching the theoretical intrinsic capacity of 4060 Ah kg-1 at increased battery voltage and battery load capability. The VB2/air couple uses an alkaline electrolyte of KOH/NaOH, employing the same oxygen air cathode extracted from the zinc/air cell 1. The carbon electrocatalyst cathode is not consumed during discharge.
There exists a need for a greater understanding the VB2 /air system in order to further improve cell performance. The properties and performance of nanoscopic VB2 materials can be explored using the cell configuration of the zinc/air cell 15,16. Electrochemical testing can be performed for nanoscopic VB2 to compare performance through percent efficiency at various rates.

<table border="1">
	<tbody>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>MATERIALS</td>
		</tr>
		<tr>
			<td>Boron</td>
			<td>Alfa Aesar</td>
			<td>11337</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Diethyl Ether</td>
			<td>J.T. Baker</td>
			<td>9244-06</td>
			<td>4L</td>
		</tr>
		<tr>
			<td>Epoxy</td>
			<td>Loctite</td>
			<td>&nbsp;</td>
			<td>Heavy Duty 5 min setting time</td>
		</tr>
		<tr>
			<td>Isopropyl Alcohol</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Panasonic 675 Zinc/Air cell</td>
			<td>Panasonic</td>
			<td>PR675H</td>
			<td>Made in Japan (not German)</td>
		</tr>
		<tr>
			<td>C-NERGY Super C65</td>
			<td>Timcal</td>
			<td>&nbsp;</td>
			<td>Graphitic carbon black</td>
		</tr>
		<tr>
			<td>Vanadium</td>
			<td>Aldrich</td>
			<td>262935</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Vanadium Diboride</td>
			<td>American Elements</td>
			<td>12007-37-3</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Zirconium Chloride</td>
			<td>Spectrum</td>
			<td>Z20001</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>EQUIPTMENT</td>
		</tr>
		<tr>
			<td>50-mL round bottom flask</td>
			<td>Fisher Scientific Co LLC</td>
			<td>CG151001</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Diagonal cutting pliers</td>
			<td>Hardware store</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Hot/stir plate</td>
			<td>IKA</td>
			<td>C-MAG HS 7</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Glove box</td>
			<td>Labconco</td>
			<td>Precision Basic</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Ten 10-mm tungsten carbide balls</td>
			<td>Lab Synergy</td>
			<td>55.0100.08</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Tungsten carbide milling jar</td>
			<td>Lab Synergy</td>
			<td>50.8600.00</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Razor blade</td>
			<td>Hardware store</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Retsch PM 100 planetary ball mill</td>
			<td>Retsch</td>
			<td>205400003</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Stir bar</td>
			<td>VWR International</td>
			<td>58947-140</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

fabrication of vb2/air cells for electrochemical testing

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

Electrochemical testing is performed to determine the performance of VB2/air batteries. The results obtained for multiple cells provide evidence for reproducibility of the cell performance. Figure 1 compares the VB2/air batteries during a 3,000 ohm (left) and 1,000 ohm (right) discharge. Note that the discharge voltage, as well as the fraction of the 4,060 Ah kg-1 intrinsic capacity is higher with the nanoscopic VB2 anode compared to the macroscopic VB2</s...

Watch this Scientific Journal Video about Fabrication of VB2/Air Cells for Electrochemical Testing at JoVE.com

Fabrication of VB2/Air Cells for Electrochemical Testing

A protocol is presented to study multi-electron metal/air battery systems by using previous technology developed for the zinc/air cell. Electrochemical testing is then performed on fabricated batteries to evaluate performance.

Fabrication of VB2/Air Cells for Electrochemical Testing

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for ...

fabrication-of-vb2air-cells-for-electrochemical-testing

Research

JoVE Journal

Engineering

Construction and Testing of Coin Cells of Lithium Ion Batteries

Rechargeable lithium ion batteries have wide applications in electronics, where customers always demand more capacity and longer lifetime. Lithium ion batteries have also been considered to be used in electric and hybrid vehicles1 or even electrical grid stabilization systems2. All these applications simulate a dramatic increase in the research and development of battery materials3-7, including new materials3,8, doping9, nanostructuring10-13, coatings or surface modifications14-17 and novel binders18. Consequently, an increasing number of physicists, chemists and materials scientists have recently ventured into this area. Coin cells are widely used in research laboratories to test new battery materials; even for the research and development that target large-scale and high-power applications, small coin cells are often used to test the capacities and rate capabilities of new materials in the initial stage. 
 In 2010, we started a National Science Foundation (NSF) sponsored research project to investigate the surface adsorption and disordering in battery materials (grant no. DMR-1006515). In the initial stage of this project, we have struggled to learn the techniques of assembling and testing coin cells, which cannot be achieved without numerous help of other researchers in other universities (through frequent calls, email exchanges and two site visits). Thus, we feel that it is beneficial to document, by both text and video, a protocol of assembling and testing a coin cell, which will help other new researchers in this field. This effort represents the "Broader Impact" activities of our NSF project, and it will also help to educate and inspire students.
In this video article, we document a protocol to assemble a CR2032 coin cell with a LiCoO2 working electrode, a Li counter electrode, and (the mostly commonly used) polyvinylidene fluoride (PVDF) binder. To ensure new learners to readily repeat the protocol, we keep the protocol as specific and explicit as we can. However, it is important to note that in specific research and development work, many parameters adopted here can be varied. First, one can make coin cells of different sizes and test the working electrode against a counter electrode other than Li. Second, the amounts of C black and binder added into the working electrodes are often varied to suit the particular purpose of research; for example, large amounts of C black or even inert powder were added to the working electrode to test the "intrinsic" performance of cathode materials14. Third, better binders (other than PVDF) have also developed and used18. Finally, other types of electrolytes (instead of LiPF6) can also be used; in fact, certain high-voltage electrode materials will require the uses of special electrolytes7.

A protocol to construct and test coin cells of lithium ion batteries is described. The specific procedures of making a working electrode, preparing a counter electrode, assembling a cell inside a glovebox and testing the cell are presented.

Rechargeable lithium ion batteries have wide applications in electronics, where customers always demand more capacity and longer lifetime.  Lithium ion ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.

Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery

We demonstrate a method for electrochemical testing of an aprotic Li-O2 battery. An aprotic Li-O2 battery is made of a Li-metal anode, an aprotic electrolyte, and an O2-breathing cathode. The aprotic electrolyte is a solution of lithium salt with aprotic solvent; and porous carbon is commonly used as the cathode substrate. To improve the performance, an electrocatalyst is deposited onto the porous carbon substrate by certain deposition methods, such as atomic layer deposition (ALD) and wet-chemistry reaction. The as-prepared cathode materials are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray absorption near edge structure (XANES). A Swagelok-type cell, sealed in a glass chamber filled with pure O2, is used for the electrochemical test on a battery test system. The cells are tested under either capacity-controlled mode or voltage controlled mode. The reaction products are investigated by electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and Raman spectroscopy to study the possible pathway of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). This protocol demonstrates a systematic and efficient arrangement of routine tests of the aprotic Li-O2 battery, including the electrochemical test and characterization of battery materials.

Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery

A protocol for the electrochemical testing of an aprotic Li-O2 battery with the preparation of electrodes and electrolytes and an introduction of the frequently used methods of characterization is presented here.

We demonstrate a method for electrochemical testing of an aprotic Li-O2 battery. An aprotic Li-O2 battery is made of a Li-metal anode, an aprotic ...

Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. 
Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties.
The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale, results from a post-test microscopy analysis are presented.

Development of new ablative materials and their numerical modeling requires extensive experimental investigation. This protocol describes procedures for material response characterization in plasma flows with the core techniques being non-intrusive methods to track the material recession along with the chemistry in the reactive boundary layer by emission spectroscopy.

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution ...

Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. The results of studies in which the etching current and the molarity of the NaOH solution used in the etching process were varied are presented. The investigation of the geometry of the tips, by imaging them with a scanning electron microscope, and by operating them in field emission mode is also described. The field emission tips produced are intended to be used as an electron beam source for ion production via electron impact ionization of background gas or vapor in Penning trap mass spectrometry applications.

A method for electrochemically etching field emission tips is presented. Etching parameters are characterized and the operation of the tips in field emission mode is investigated.

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. ...

Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active layer which consists of blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and &#960;-conjugated triphenylamine molecules. This white light emission originates from exciplexes formed between PFD and amines in electronically excited states. A device containing PFD, 4,4&#39;,4&#39;&#39;-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA), Poly(ethylene oxide) and K2CF3SO3 showed white light emission with Commission internationale de l&#39;&#233;clairage (CIE) coordinates of (0.33, 0.43) and a Color Rendering Index (CRI) of Ra = 73 at an applied voltage of 3.5 V. Constant voltage measurements showed that the CIE coordinates of (0.27, 0.37), Ra of 67, and the emission color observed immediately after application of a voltage of 5 V were nearly unchanged and stable after 300 sec.

The authors present a method for fabricating stable white-light-emitting electrochemical cells utilizing emission from exciplexes formed between a blue-emitting fluorene polymer and aromatic amines.

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active ...

Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering thermal wave fields that are disturbed by the defect. This effect is measured and used to locate the defect. We form the destructively interfering wave fields by using a modified projector. The original light engine of the projector is replaced with a fiber-coupled high-power diode laser. Its beam is shaped and aligned to the projector&#39;s spatial light modulator and optimized for optimal optical throughput and homogeneous projection by first characterizing the beam profile, and, second, correcting it mechanically and numerically. A high-performance infrared (IR) camera is set up according to the tight geometrical situation (including corrections of the geometrical image distortions) and the requirement to detect weak temperature oscillations at the sample surface. Data acquisition can be performed once a synchronization between the individual thermal wave field sources, the scanning stage, and the IR camera is established by using a dedicated experimental setup which needs to be tuned to the specific material being investigated. During data post-processing, the relevant information on the presence of a defect below the surface of the sample is extracted. It is retrieved from the oscillating part of the acquired thermal radiation coming from the so-called depletion line of the sample surface. The exact location of the defect is deduced from the analysis of the spatial-temporal shape of these oscillations in a final step. The method is reference-free and very sensitive to changes within the thermal wave field. So far, the method has been tested with steel samples but is applicable to different materials as well, in particular to temperature sensitive materials.

This method aims at locating vertical subsurface defects. Here, we couple a laser with a spatial light modulator and trigger its video input to heat a sample surface deterministically with two anti-phased modulated lines while acquiring highly resolved thermal images. The defect position is retrieved from evaluating thermal wave interference minima.

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering ...

Focused Ion Beam Fabrication of LiPON-based Solid-state Lithium-ion Nanobatteries for In Situ Testing

Solid-state electrolytes are a promising replacement for current organic liquid electrolytes, enabling higher energy densities and improved safety of lithium-ion (Li-ion) batteries. However, a number of setbacks prevent their integration into commercial devices. The main limiting factor is due to nanoscale phenomena occurring at the electrode/electrolyte interfaces, ultimately leading to degradation of battery operation. These key problems are highly challenging to observe and characterize as these batteries contain multiple buried interfaces. One approach for direct observation of interfacial phenomena in thin film batteries is through the fabrication of electrochemically active nanobatteries by a focused ion beam (FIB). As such, a reliable technique to fabricate nanobatteries was developed and demonstrated in recent work. Herein, a detailed protocol with a step-by-step process is presented to enable the reproduction of this nanobattery fabrication process. In particular, this technique was applied to a thin film battery consisting of LiCoO2/LiPON/a-Si, and has further been previously demonstrated by in situ cycling within a transmission electron microscope.

Focused Ion Beam Fabrication of LiPON-based Solid-state Lithium-ion Nanobatteries for In Situ Testing

A protocol for the fabrication of electrochemically active LiPON-based solid-state lithium-ion nanobatteries using a focused ion beam is presented.

Solid-state electrolytes are a promising replacement for current organic liquid electrolytes, enabling higher energy densities and improved safety of ...

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in industry. The wettability of the produced surface was analyzed by bouncing drop experiments and the topography was analyzed by confocal microscopy. In addition, we show various methodologies to measure its durability and anti-icing properties. Superhydrophobic surfaces hold a special texture that must be preserved to keep their water-repellency. To fabricate durable surfaces, we followed two strategies to incorporate a resistant texture. The first strategy is a direct incorporation of roughness to the metal substrate by acid etching. After this surface texturization, the surface energy was decreased by silanization or fluoropolymer deposition. The second strategy is the growth of a ceria layer (after surface texturization) that should enhance the surface hardness and corrosion resistance. The surface energy was decreased with a stearic acid film.
The durability of the superhydrophobic surfaces was examined by a particle impact test, mechanical wear by lateral abrasion, and UV-ozone resistance. The anti-icing properties were explored by studying the ability to repeal subcooled water, freezing delay, and ice adhesion.

We illustrate several methodologies to produce superhydrophobic metal surfaces and to explore their durability and anti-icing properties.

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in ...