Primary funding for the work was provided by the Electron Microscopy of Soft Matter Program from the Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The battery assembly portion of the project was supported by the BATT program from the Vehicle Technologies program, through the Office of Energy Efficiency and Renewable Energy under U.S. DOE Contract DE-AC02-05CH11231. Hard X-ray microtomography experiments were performed at the Advanced Light Source which is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Katherine J. Harry was supported by a National Science Foundation Graduate Research Fellowship.

1. Electrolyte Preparation
<ol>
	<li>Synthesize a 240 kg/mol &#8211; 260 kg/mol poly(styrene) - block - poly(ethylene oxide) copolymer (SEO) using anionic polymerization.
	<ol>
		<li>Perform all additional sample preparation in an Argon glovebox where the water and oxygen levels are controlled and remain &#60;5 ppm.</li>
		<li>Dissolve 0.3 g of polymer in anhydrous N-methyl-2-pyrrolidone (NMP) with dry lithium bis(trifluoromethane)sulfonimide (LiTFSI) salt. Use a LiTFSI salt to SEO mass ratio of 0.275 and an NMP to SEO mass ratio of 13.13. 
		Note: This quantity of polymer will yield a membrane large enough to make approximately 20 samples.</li>
		<li>Cast all of the polymer and salt mixture prepared in the steps above onto an approximately 15 cm by 15 cm square piece of nickel foil using a doctor blade. Dry the resulting film at 60 &#176;C O/N.</li>
		<li>After drying, peel the film from the Nickel foil and allow to dry further under vacuum at 90 &#176;C.</li>
		<li>Wrap the resulting freestanding film in Nickel foil and store inside an air-tight box in the glovebox for later use.</li>
	</ol>
	</li>
</ol>
2. Lithium &#8211; Lithium Symmetric Cell Preparation
<ol>
	<li>Use a 7/16 in&#160;diameter, round metal punch to cut out two lithium metal electrodes from a roll of 99.9% pure, battery-grade lithium metal foil.</li>
	<li>Use a 1/2 in&#160;diameter metal punch to cut out a piece of polymer electrolyte film. 
	Note: The lithium metal is softer and easier to punch than the polymer electrolyte.</li>
	<li>Sandwich the polymer electrolyte film between the two lithium metal electrodes and press the nickel tabs onto the electrodes.</li>
	<li>Vacuum seal the sample in an air-tight pouch made of polypropylene and nylon lined aluminum. 
	Note: One of the lithium electrodes is easily swapped with a cathode if one wants to study a full battery.</li>
</ol>
3. Symmetric Cell Cycling
<ol>
	<li>Place the vacuum-sealed sample into an oven held at 90 &#176;C and cycle using electrochemical cycling equipment. Heat the sample during cycling to achieve reasonable ionic conductivity through the electrolyte membrane. For safety, ensure that the sample does not approach the lithium metal melting point of 180 &#176;C.</li>
	<li>Pass a current density of 0.175 mA/cm2 through the sample for 4 hr and follow with a 45 min&#160;rest. Next, pass a current density of -0.175 mA/cm2 through the sample for 4 hr and follow with a 45 min&#160;rest. Repeat this cycling routine as many times as desired.</li>
	<li>Observe the voltage response for this current density passed through a 30 &#181;m thick SEO electrolyte and compare with that shown in Figure 1. Stop the cycling routine when the cell voltage response drops to 0.00 V, because the battery has failed by short-circuit indicating the growth of lithium dendrites.</li>
</ol>
4. Synchrotron Hard X-ray Microtomography Imaging
<ol>
	<li>After the symmetric cell is cycled, bring it back into the glove box and remove it from its pouch.</li>
	<li>Use a 1/8 inch metal punch to cut out the center portion of the cell.Vacuum seal the center portion of the cell in pouch material and remove from the glovebox for transport to the synchrotron facility. 
	Note: By imaging a sample with a reduced diameter, the amount of material outside of the field of view of the X-ray detector is reduced. This improves the overall image quality by reducing noise caused by this extra material. Furthermore, removal of the highly X-ray absorptive Nickel current collectors is necessary, for this particular pouch design, to obtain clear X-ray images.</li>
	<li>Once at the beamline, use polyimide tape to affix the sample to the sample stage. If desired, tape a small metal marker on top of the sample to aid with alignment. Place the metal marker roughly in the center of the sample to mark the location around which the sample will rotate once aligned.</li>
	<li>Use 20 keV X-rays to image the sample with an exposure time optimized for the system. Optimize the exposure time by balancing the scan time and the number of counts per image. Estimate the total scan time by multiplying the exposure time by the number of images collected.
	<ol>
		<li>Here, use an exposure time of 300 msec, resulting in a scan time of 5 to 10 min.</li>
	</ol>
	</li>
	<li>Measure the pixel size associated with the optical lenses at the beginning of every beamtime shift. 
	Note: For the 4x lens used to take the image shown in Figure 2, the pixel size was 1.61 &#181;m/pixel. Higher magnification lenses (10x and 20x) are also available for use.</li>
	<li>Position and align the sample on a rotation stage with respect to the detection system so that it remains in the detector&#8217;s field of view as it rotates through 180&#176;.</li>
	<li>Position the sample as close to the detector as is possible while ensuring that the sample does not hit the detector at any rotation angle. 
	Note: As the sample to detector distance increases, the Fresnel phase contrast will become more pronounced in the reconstructed images. This can obscure features and result in poorer resolution. For pouch cells, the sample to detector distance is typically on the order of 3 cm away from the detector.</li>
	<li>Once aligned, perform a scan consisting of 1,025 images collected over sample rotations between 0 and 180&#176;. Collect &#8220;Bright field&#8221; (also known as &#8220;flat field&#8221; or &#8220;background&#8221;) images by moving the sample out of the field of view. Additionally, collect &#8220;dark field&#8221; images by taking images while the beam is off. Use these to normalize the sample images for inhomogeneous illumination, scintillator response, and CCD camera response.</li>
</ol>
5. Image Reconstruction
<ol>
	<li>Tomographically reconstruct the set of 1,025 radiographs into a stack of images where each image represents a slice in the volume using the following procedure.
	<ol>
		<li>First, normalize the images by subtracting the &#8220;dark field&#8221; images from both the radiograph images and the &#8220;bright field&#8221; images. Divide the resulting radiograph images divided by the resulting &#8220;bright field&#8221; images.</li>
		<li>Next, perform tomographic reconstruction, the process by which the series of projection angles is transformed into a 3D image, on the normalized radiograph images according to manufacturer&#8217;s protocol. 
		Note: The reconstruction software outputs a series of images, each representing a horizontal slice through the sample.When stacked, this set of reconstructed images form a three-dimensional X-ray absorption map of the sample.</li>
	</ol>
	</li>
	<li>Visualize the individual slices or the sample in three-dimensions to see what the sample looks like on the inside.</li>
</ol>
6. Data Visualization and Processing
<ol>
	<li>Use one of a multitude of commercial and open source image processing software packages available for data visualization and analysis.22, 23</li>
	<li>Upon opening the stack of reconstructed images with the desired software, create orthoslices to show the xy, xz, and yz perspectives of the reconstructed data.</li>
	<li>Pan through these images and search for features of interest, like the lithium dendrite shown in Figure 2.</li>
	<li>Next, use segmentation (digital labeling) and 3D rendering tools to render the feature of interest in three-dimensions.</li>
	<li>To digitally segment the image, create a label field and use thresholding tools to select regions of the sample corresponding to a material.</li>
	<li>To recreate an image like that shown in Figure 2B, label the dark pixels lithium and the bright pixels electrolyte. Label the lithium contained in the dendrite separately from the top and bottom lithium electrodes.
	<ol>
		<li>Render the dendritic lithium in orange and the polymer electrolyte in blue. Render the top and bottom lithium metal electrodes in gray and adjust the transparency value to reveal the orange dendritic lithium. Rotate this three-dimensional reconstruction to view the structure from many perspectives.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Bruce, P. G., Freunberger, S. A., Hardwick, L. J., Tarascon, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Li-O-2+and+Li-S+batteries+with+high+energy+storage.">Li-O-2 and Li-S batteries with high energy storage.</a> Nat Mater. 11, 19-29 (2012).</li><li>Balsara, N. P., Newman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparing+the+Energy+Content+of+Batteries,+Fuels,+and+Materials.">Comparing the Energy Content of Batteries, Fuels, and Materials.</a> J Chem Educ. 90, 446-452 (2013).</li><li>Girishkumar, G., McCloskey, B., Luntz, A. C., Swanson, S., Wilcke, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lithium+-+Air+Battery:+Promise+and+Challenges.">Lithium - Air Battery: Promise and Challenges.</a> J Phys Chem Lett. 1, 2193-2203 (2010).</li><li>Selim, R., Bro, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Some+observations+on+rechargeable+lithium+electrodes+in+a+propylene+carbonate+electrolyte.">Some observations on rechargeable lithium electrodes in a propylene carbonate electrolyte.</a> J Electrochem Soc. 121, 1457-1459 (1974).</li><li>Aurbach, D., Zinigrad, E., Cohen, Y., Teller, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+short+review+of+failure+mechanisms+of+lithium+metal+and+lithiated+graphite+anodes+in+liquid+electrolyte+solutions.">A short review of failure mechanisms of lithium metal and lithiated graphite anodes in liquid electrolyte solutions.</a> Solid State Ionics. 148, 405-416 (2002).</li><li>Monroe, C., Newman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dendrite+Growth+in+Lithium/Polymer+Systems.">Dendrite Growth in Lithium/Polymer Systems.</a> J Electrochem Soc. 150, A1377 (2003).</li><li>Barton, J. L., Bockris, J. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Electrolytic+Growth+of+Dendrites+from+Ionic+Solutions.">The Electrolytic Growth of Dendrites from Ionic Solutions.</a> Proc R Soc Ser A. 268, 485-505 (1962).</li><li>Bhattacharyya, R., 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=In+situ+NMR+observation+of+the+formation+of+metallic+lithium+microstructures+in+lithium+batteries.">In situ NMR observation of the formation of metallic lithium microstructures in lithium batteries.</a> Nat Mater. 9, 504-510 (2010).</li><li>Chandrashekar, 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=7Li+MRI+of+Li+batteries+reveals+location+of+microstructural+lithium.">7Li MRI of Li batteries reveals location of microstructural lithium.</a> Nat Mater. 11, 311-315 (2012).</li><li>Arora, P., White, R. E., Doyle, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capacity+fade+mechanisms+and+side+reactions+in+lithium-ion+batteries.">Capacity fade mechanisms and side reactions in lithium-ion batteries.</a> J Electrochem Soc. 145, 3647-3667 (1998).</li><li>Ebner, M., Marone, F., Stampanoni, M., Wood, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+and+Quantification+of+Electrochemical+and+Mechanical+Degradation+in+Li+Ion+Batteries.">Visualization and Quantification of Electrochemical and Mechanical Degradation in Li Ion Batteries.</a> Science. 342, 716-720 (2013).</li><li>Qi, Y., Harris, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Situ+Observation+of+Strains+during+Lithiation+of+a+Graphite+Electrode.">In Situ Observation of Strains during Lithiation of a Graphite Electrode.</a> J Electrochem Soc. 157, A741-A747 (2010).</li><li>Eastwood, D. 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=Three-dimensional+characterization+of+electrodeposited+lithium+microstructures+using+synchrotron+X-ray+phase+contrast+imaging.">Three-dimensional characterization of electrodeposited lithium microstructures using synchrotron X-ray phase contrast imaging.</a> Chem Commun. , (2014).</li><li>Shui, J. -. L., 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=Reversibility+of+anodic+lithium+in+rechargeable+lithium&#8211;oxygen+batteries.">Reversibility of anodic lithium in rechargeable lithium&#8211;oxygen batteries.</a> Nat commun. 4, (2013).</li><li>Harry, K. J., Hallinan, D. T., Parkinson, D. Y., MacDowell, A. A., Balsara, N. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+subsurface+structures+underneath+dendrites+formed+on+cycled+lithium+metal+electrodes.">Detection of subsurface structures underneath dendrites formed on cycled lithium metal electrodes.</a> Nat Mater. 13, 69-73 (2014).</li><li>Baruchel, J., 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=Advances+in+synchrotron+hard+X-ray+based+imaging.">Advances in synchrotron hard X-ray based imaging.</a> Cr Phys. 9, 624-641 (2008).</li><li>Flannery, B. P., Deckman, H. W., Roberge, W. G., D'Amico, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-Dimensional+X-ray+Microtomography.">Three-Dimensional X-ray Microtomography.</a> Science. 237, 1439-1444 (1987).</li><li>Singh, M., 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=Effect+of+molecular+weight+on+the+mechanical+and+electrical+properties+of+block+copolymer+electrolytes.">Effect of molecular weight on the mechanical and electrical properties of block copolymer electrolytes.</a> Macromolecules. 40, 4578-4585 (2007).</li><li>Monroe, C., Newman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Impact+of+Elastic+Deformation+on+Deposition+Kinetics+at+Lithium/Polymer+Interfaces.">The Impact of Elastic Deformation on Deposition Kinetics at Lithium/Polymer Interfaces.</a> J Electrochem Soc. 152, A396-1149 (2005).</li><li>Stone, G. M., 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=Resolution+of+the+Modulus+versus+Adhesion+Dilemma+in+Solid+Polymer+Electrolytes+for+Rechargeable+Lithium+Metal+Batteries.">Resolution of the Modulus versus Adhesion Dilemma in Solid Polymer Electrolytes for Rechargeable Lithium Metal Batteries.</a> J Electrochem Soc. 159, A222-A227 (2012).</li><li>Panday, A., 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=Effect+of+Molecular+Weight+and+Salt+Concentration+on+Conductivity+of+Block+Copolymer+Electrolytes.">Effect of Molecular Weight and Salt Concentration on Conductivity of Block Copolymer Electrolytes.</a> Macromolecules. 42, 4632-4637 (2009).</li><li>Schneider, C. A., Rasband, W. S., Eliceiri, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NIH+Image+to+ImageJ:+25+years+of+image+analysis.">NIH Image to ImageJ: 25 years of image analysis.</a> Nat methods. 9, 671-675 (2012).</li><li>Henke, B. L., Gullikson, E. M., Davis, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-Ray+Interactions+-+Photoabsorption,+Scattering,+Transmission+and+Reflection+at+E=50-30,000+Ev,+Z=1-92+(Vol+54,+Pg+181,+1993).">X-Ray Interactions - Photoabsorption, Scattering, Transmission and Reflection at E=50-30,000 Ev, Z=1-92 (Vol 54, Pg 181, 1993).</a> Atom Data Nucl Data. 55, 349-349 (1993).</li></ol>

The authors have nothing to disclose.

Hard X-ray microtomography is especially well-suited for air-sensitive samples, like many electrochemically active materials, since the X-rays can penetrate through protective pouch material, enabling facile imaging of the sample without exposure to air. Perhaps the most valuable characteristic of this imaging technique is that the penetrating X-rays allow the user to see inside of the sample without destroying it. Most common imaging techniques, like scanning electron microscopy and traditional optical microscopy, can o...

Researchers are actively investigating battery chemistries with theoretical energy densities over an order of magnitude larger than traditional lithium-ion batteries.1,2 These high-energy-density batteries will make electric vehicles more competitive with their gasoline-powered counterparts.3 However, these new chemistries have several failure modes that preclude their use in commercial technologies. For example, these battery chemistries require a lithium metal anode to achieve large enhancements in energy density; unfortunately, lithium metal is prone to dendrite growth as lithium ions are reduced at the anode surface during charging.4-9 Additionally, breakage of active particles in the cathode and poor adhesion within the battery can cause cell failure.10
Many modes of battery failure occur on the micrometer scale. However, most battery materials are air sensitive making sample preparation for analysis by electron microscopy and traditional optical microscopy difficult. Synchrotron hard X-ray microtomography allows one to visualize the interior of a battery without disassembly.11-14 Furthermore, the technique produces a three-dimensional (3D) reconstruction of the assembled cell making it easy to find locations of failure.15 Finding robust techniques that enable researchers to develop the scientific understanding required to accurately predict the lifetime of a battery is critical for the design of next generation battery technologies. The procedure discussed herein will specifically demonstrate how one can prepare and image model batteries to study the growth of lithium metal dendrites through solid polymer electrolyte membranes.
Computed tomography (CT) scanning is not a new technique and has been used frequently for failure analysis in industry. Synchrotron-based X-ray microtomography is advantageous because the high brightness and flux of the source allow collection of images with high resolution and good signal to noise in a much shorter amount of time.16 Additionally, one can take advantage of the X-ray energy resolution to image at energies around a chemical species&#8217; absorption edge, causing the components containing that chemical species to be identified.17 It was found that the synchrotron source provides sufficient flux to achieve good contrast between lithium metal and solid polymer electrolyte membranes enabling one to image lithium metal dendrites.15
The study discussed herein uses a high modulus, block copolymer electrolyte membrane.18 These high modulus membranes suppress lithium dendrite growth, lengthening the lifetime of batteries.19,20 However, dendrites still eventually puncture the membrane causing the battery to fail by short-circuit. It is important to understand the nature of dendrite formation and growth in these high modulus electrolyte membranes in order to design strategies to prevent their growth.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Anhydrous N-methyl-2-pyrrolidone&#160;</td>
			<td>MILLIPORE</td>
			<td>MX1396-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Lithium bis(trifluoromethane)sulfonamide</td>
			<td>MILLIPORE</td>
			<td>8438730010</td>
			<td></td>
		</tr>
		<tr>
			<td>Lithium metal</td>
			<td>FMC Lithium</td>
			<td>None</td>
			<td>Lectro Max 100</td>
		</tr>
		<tr>
			<td>Pouch material</td>
			<td>MTI Corporation</td>
			<td>EQ-alf-400-7.5M</td>
			<td></td>
		</tr>
		<tr>
			<td>Nickel tabs</td>
			<td>MTI Corporation</td>
			<td>EQ-PLiB-NTA3</td>
			<td></td>
		</tr>
	</tbody>
</table>

failure analysis of batteries using synchrotron-based hard x-ray microtomography

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent of lithium-ion batteries, researchers have known that the lithium metal anode has the highest theoretical energy density of any anode material. However, rechargeable batteries containing a lithium metal anode are not widely used in consumer products because the growth of lithium dendrites from the anode upon charging of the battery causes premature cell failure by short circuit. Lithium dendrites can also form in commercial lithium-ion batteries with graphite anodes if they are improperly charged. We demonstrate that lithium dendrite growth can be studied using synchrotron-based hard X-ray microtomography. This non-destructive imaging technique allows researchers to study the growth of lithium dendrites, in addition to other morphological changes inside batteries, and subsequently develop methods to extend battery life.

When the symmetric lithium-lithium cells described above are cycled at 90 &#176;C, the voltage response looks like that shown in Figure 1. Eventually, lithium dendrites will grow through the electrolyte and cause the cell to fail by short circuit. When this happens, the voltage response to the applied current will drop down to 0.00 V. Dendrites, like the one shown in Figure 2 appear in samples that have failed by short circuit. Non-electrolyte spanning dendrites are also found in the sam...

Watch this Scientific Journal Video about Failure Analysis of Batteries Using Synchrotron-based Hard X-ray Microtomography at JoVE.com

Failure Analysis of Batteries Using Synchrotron-based Hard X-ray Microtomography

Synchrotron-based hard X-ray microtomography is used to image the electrochemical growth of dendrites from a lithium metal electrode through a solid polymer electrolyte membrane.

Sinkrotron merkezli Sert X-ışını Microtomography kullanılması Akü Arıza Analizi

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent ...

failure-analysis-batteries-using-synchrotron-based-hard-x-ray

Research

JoVE Journal

Engineering

8.8K Görüntüleme.  University of California Berkeley. Synchrotron-based hard X-ray microtomography is used to image the electrochemical growth of dendrites from a lithium metal electrode through a solid polymer electrolyte membrane.

Video: Failure Analysis of Batteries Using Synchrotron-based Hard X-ray Microtomography

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.

İnşaat ve Lityum İyon pillerin Coin Hücre Testi

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

Mühendislik

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

Li-ion batteries are widely used in portable electronic devices and are considered as promising candidates for higher-energy applications such as electric vehicles.1,2 However, many challenges, such as energy density and battery lifetimes, need to be overcome before this particular battery technology can be widely implemented in such applications.3 This research is challenging, and we outline a method to address these challenges using in situ NPD to probe the crystal structure of electrodes undergoing electrochemical cycling (charge/discharge) in a battery. NPD data help determine the underlying structural mechanism responsible for a range of electrode properties, and this information can direct the development of better electrodes and batteries.
We briefly review six types of battery designs custom-made for NPD experiments and detail the method to construct the &#8216;roll-over&#8217; cell that we have successfully used on the high-intensity NPD instrument, WOMBAT, at the Australian Nuclear Science and Technology Organisation (ANSTO). The design considerations and materials used for cell construction are discussed in conjunction with aspects of the actual in situ NPD experiment and initial directions are presented on how to analyze such complex in situ data.

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

We describe the design and construction of an electrochemical cell for the examination of electrode materials using in situ neutron powder diffraction (NPD). We briefly comment on alternate in situ NPD cell designs and discuss methods for the analysis of the corresponding in situ NPD data produced using this cell.

Yerinde Nötron Toz Kırınım olarak Ismarlama Lityum-iyon Piller kullanma

Li-ion batteries are widely used in portable electronic devices and are considered as promising candidates for higher-energy applications such as electric ...

Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography

X-ray microtomography was used to image, at a resolution of 6.6 &#181;m, the pore-scale arrangement of residual carbon dioxide ganglia in the pore-space of a carbonate rock at pressures and temperatures representative of typical formations used for CO2 storage. Chemical equilibrium between the CO2, brine and rock phases was maintained using a high pressure high temperature reactor, replicating conditions far away from the injection site. Fluid flow was controlled using high pressure high temperature syringe pumps. To maintain representative in-situ conditions within the micro-CT scanner a carbon fiber high pressure micro-CT coreholder was used. Diffusive CO2 exchange across the confining sleeve from the pore-space of the rock to the confining fluid was prevented by surrounding the core with a triple wrap of aluminum foil. Reconstructed brine contrast was modeled using a polychromatic x-ray source, and brine composition was chosen to maximize the three phase contrast between the two fluids and the rock. Flexible flow lines were used to reduce forces on the sample during image acquisition, potentially causing unwanted sample motion, a major shortcoming in previous techniques. An internal thermocouple, placed directly adjacent to the rock core, coupled with an external flexible heating wrap and a PID controller was used to maintain a constant temperature within the flow cell. Substantial amounts of CO2 were trapped, with a residual saturation of 0.203 &#177; 0.013, and the sizes of larger volume ganglia obey power law distributions, consistent with percolation theory.

We present a methodology for the imaging of multiple fluid phases at reservoir conditions by the use of x-ray microtomography. We show some representative results of capillary trapping in a carbonate rock sample.

Çoklu Akışkan Aşama Rezervuar Durumu Gözenek ölçekli Görüntüleme X-ışını Microtomography kullanma

X-ray microtomography was used to image, at a resolution of 6.6 &#181;m, the pore-scale arrangement of residual carbon dioxide ganglia in the pore-space ...

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

Bireysel Nanopartiküller 3D Elemental Haritalama için Enerji Dağılımı X-ışını Tomografi

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is reported. The measurements were demonstrated at the 1-BM bending magnet beamline of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). By using a 2-D checkerboard &#960;/2 phase-shift grating, transverse coherence lengths were obtained along the vertical and horizontal directions as well as along the 45&#176; and 135&#176; directions to the horizontal direction. Following the technical details specified in this paper, interferograms were measured at different positions downstream of the phase grating along the beam propagation direction. Visibility values of each interferogram were extracted from analyzing harmonic peaks in its Fourier Transformed image. Consequently, the coherence length along each direction can be extracted from the evolution of visibility as a function of the grating-to-detector distance. The simultaneous measurement of coherence lengths in four directions helped identify the elliptical shape of the coherence area of the Gaussian-shaped X-ray source. The reported technique for multiple-direction coherence characterization is important for selecting the appropriate sample size and orientation as well as for correcting the partial coherence effects in coherence scattering experiments. This technique can also be applied for assessing coherence preserving capabilities of X-ray optics.

The measurement protocol and data analysis procedure are given for obtaining transverse coherence of a synchrotron radiation X-ray source along four directions simultaneously using a single 2-D checkerboard phase grating. This simple technique can be applied for complete transverse coherence characterization of X-ray sources and X-ray optics.

2-D Dama Faz GRATING kullanarak birden çok Directions boyunca X-ışını Işın Tutarlılık Ölçümü

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is ...

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

Çok ölçekli Üç boyutlu Mikroelektronik paketleri Soruşturma Sinkrotron Radyasyon Microtomography kullanma

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

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.

Protonsuz Li-O Elektrokimyasal Testi Protokol ve Karakterizasyonu<sub&gt; 2</sub&gt; Pil

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 ...

Dynamic Pore-scale Reservoir-condition Imaging of Reaction in Carbonates Using Synchrotron Fast Tomography

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve geologic seals and allow CO2 to escape. However, the dissolution processes at reservoir conditions are poorly understood. Thus, time-resolved experiments are needed to observe and predict the nature and rate of dissolution at the pore scale. Synchrotron fast tomography is a method of taking high-resolution time-resolved images of complex pore structures much more quickly than traditional &#181;-CT. The Diamond Lightsource Pink Beam was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 hours. The images were segmented and the porosity and permeability were measured using image analysis and network extraction. Porosity increased uniformly along the length of the sample; however, the rate of increase of both porosity and permeability slowed at later times.

Synchrotron fast tomography was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 h.

Sinkrotron Hızlı Tomografi ile Karbonat içinde Reaksiyon Dinamik Gözenek ölçekli Rezervuar-koşul Görüntüleme

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve ...

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line intensity ratios. By using a Johann spectrometer viewing the plasma, it is possible to construct profiles of plasma parameters such as density, temperature, and velocity with good spatial and time resolution. However, benchmarking atomic code modeling of X-ray spectra obtained from well-diagnosed laboratory plasmas is important to justify use of such spectra to determine plasma parameters when other independent diagnostics are not available. This manuscript presents the operation of the High Resolution X-ray Crystal Imaging Spectrometer with Spatial Resolution (HIREXSR), a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma. In addition, this manuscript covers a laser blow-off system that can introduce such ions to the plasma with precise timing to allow for perturbative studies of transport in the plasma.

X-ray spectra provide a wealth of information on high temperature plasmas. This manuscript presents the operation of a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma.

Yüksek Sıcaklık Plazma Tanı olarak Kullanım için X-ışını Görüntüleme Kristal Spektroskopisi Uygulanması

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.