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. Preparación de electrolitos <ol><li> Sintetizar un 240 kg / mol - 260 kg / mol de poli (estireno) - bloque - poli (óxido de etileno) copolímero (SEO) usando polimerización aniónica. <ol><li> Realizar toda la preparación de la muestra adicional en una guantera Argón donde se controlan los niveles de agua y oxígeno y permanecer &lt;5 ppm. </li><li> Disolver 0,3 g de polímero en anhidro N-metil-2-pirrolidona (NMP) con bis de litio seco (trifluorometano) sulfonimida (LiTFSI) sal. Utilice una sal LiTFSI a masa SEO de 0.275 y un NMP de SEO relación de masa de 13,13. Nota: Esta cantidad de polímero producirá una membrana suficientemente grande para hacer aproximadamente 20 muestras. </li><li> Reparto de toda la mezcla de polímero y la sal preparada en los pasos anteriores en un aproximadamente 15 cm por 15 cm pedazo cuadrado de papel de aluminio de níquel utilizando una rasqueta. Secar la película resultante a 60 ° CO / N. </li><li> Después de secar, pelar la película de la lámina de níquel y dejar secar aún más al vacío a 90 ° C. </li><li> Envuelva la película independiente que resulta en papel de aluminio, níquel y almacenar dentro de una caja hermética en la guantera para su uso posterior. </li></ol></li></ol> 2. litio - litio simétrica Preparación celular <ol><li> Utilice un 7/16 de diámetro, punzón redondo de metal para cortar dos electrodos de metal de litio de un rollo de 99,9% de pureza, la batería de grado hoja de metal de litio. </li><li> Utilice una media de punzón de metal diámetro para cortar un trozo de película de electrolito de polímero. Nota: El metal de litio es más suave y más fácil de golpear que el electrolito de polímero. </li><li> Intercalar la película de electrolito de polímero entre los dos electrodos de metal litio y presione las lengüetas de níquel sobre los electrodos. </li><li> Sello de vacío de la muestra en una bolsa hermética de polipropileno y nylon forrado de aluminio. Nota: Uno de los electrodos de litio es fácilmente intercambiados con un cátodo si se quiere estudiar una batería llena. </li></ol> 3. simétrica celular ciclina<html> g <ol><li> Coloque la muestra sellada al vacío en un horno mantenido a 90 ° C y el ciclo utilizando un equipo de ciclismo electroquímica. Calentar la muestra durante el ciclismo para lograr conductividad iónica razonable a través de la membrana de electrolito. Por razones de seguridad, asegúrese de que la muestra no se acerca al punto de fusión del metal de litio de 180 ° C. </li><li> Pasar una densidad de corriente de 0.175 mA / cm 2 a través de la muestra durante 4 horas y seguir con un descanso de 45 minutos. A continuación, pasar a una densidad de corriente de -0.175 mA / cm 2 a través de la muestra durante 4 horas y seguir con un descanso de 45 minutos. Repita esta rutina ciclo tantas veces como se desee. </li><li> Observar la respuesta de tensión para esta densidad de corriente que pasa a través de una 30 m de espesor electrolito SEO y comparar con la mostrada en la Figura 1. Detener la rutina de ciclismo cuando la respuesta voltaje de la celda cae a 0,00 V, debido a que la batería no ha pasado por corto-circuito que indica la crecimiento de dendritas de litio. </li></ol>TÍTULO &quot;Imaging Microtomografía&gt; 4. de rayos X de sincrotrón duro <ol><li> Después se realiza un ciclo de la célula simétrica, traerlo de vuelta a la guantera y extraerlo de su bolsa. </li><li> Use un punzón de metal de 1/8 de pulgada para cortar la porción central de la cell.Vacuum sellar la parte central de la celda en la material de la bolsa y retirar de la caja de guantes para su transporte a la instalación de sincrotrón. Nota: por imágenes de una muestra con un diámetro reducido, se reduce la cantidad de material fuera del campo de visión del detector de rayos X. Esto mejora la calidad general de la imagen mediante la reducción de ruido causado por este material extra. Por otra parte, la eliminación de los altamente de rayos X de níquel de absorción colectores de corriente es necesario, para este diseño de la bolsa en particular, para obtener imágenes claras de rayos X. </li><li> Una vez en la línea de luz, utilizar la cinta de poliimida para fijar la muestra a la etapa de la muestra. Si se desea, con cinta adhesiva un pequeño marcador de metal en la parte superior de la muestra para ayudar con la alineación. Coloca el marcador de metal más o menos en el centro del sample para marcar la ubicación alrededor de la cual la muestra girará una vez alineados. </li><li> Utilice rayos X 20 keV a la imagen de la muestra con un tiempo de exposición optimizado para el sistema. Optimizar el tiempo de exposición al equilibrar el tiempo de ciclo y el número de cuentas por imagen. Estimar el tiempo de ciclo total de multiplicando el tiempo de exposición por el número de imágenes recogidas. <ol><li> Aquí, usar un tiempo de exposición de 300 ms, lo que resulta en un tiempo de exploración de 5 a 10 min. </li></ol></li><li> Medir el tamaño de píxel asociado con las lentes ópticas al principio de cada turno de tiempo de haz. Nota: Para la lente 4x utilizado para tomar la imagen mostrada en la Figura 2, el tamaño de píxel era 1,61 m / pixel. Lentes de aumento mayor (10x y 20x) también están disponibles para su uso. </li><li> Posición y alinear la muestra en una etapa de rotación con respecto al sistema de detección de modo que permanezca en el campo de visión del detector a medida que gira a través de 180 °. </li><li> Coloque la muestra tan cercael detector como es posible asegurando al mismo tiempo que la muestra no golpea el detector en cualquier ángulo de rotación. Nota: Como la muestra al detector aumenta la distancia, el contraste de fase de Fresnel será más pronunciado en las imágenes reconstruidas. Esto puede oscurecer características y dar lugar a la resolución más pobre. Para las células de la bolsa, la muestra a distancia detector es típicamente del orden de 3 cm de distancia del detector. </li><li> Una vez alineado, realizar una exploración que consiste en 1.025 imágenes recogidas durante las rotaciones de muestreo entre 0 y 180 °. Recoger &quot;campo brillante&quot; (también conocido como &quot;campo plano&quot; o &quot;fondo&quot;) imágenes moviendo la muestra fuera del campo de visión. Además, recoge las imágenes de &quot;campo oscuro&quot; tomando imágenes mientras el haz está apagado. Utilice éstos para normalizar las imágenes de muestra para la iluminación no homogénea, la respuesta de centelleo, y la respuesta de la cámara CCD. </li></ol> Reconstrucción 5. Imagen <ol><li> Tomográficamentereconstruir el conjunto de 1.025 radiografías en una pila de imágenes, donde cada imagen representa una rebanada en el volumen mediante el siguiente procedimiento. <ol><li> En primer lugar, normalizar las imágenes restando las imágenes de &quot;campo oscuro&quot; tanto de las imágenes de la radiografía y las imágenes &quot;de campo brillante&quot;. Divida las imágenes de la radiografía resultante dividida por las imágenes resultantes &quot;de campo brillante&quot;. </li><li> A continuación, realice reconstrucción tomográfica, el proceso por el cual se transformó la serie de ángulos de proyección en una imagen en 3D, en las imágenes de radiografía normalizados de acuerdo con el protocolo del fabricante. Nota: El software de reconstrucción da salida a una serie de imágenes, cada uno representando una rebanada horizontal a través de la sample.When apilado, este conjunto de imágenes reconstruidas forman un mapa absorción de rayos X en tres dimensiones de la muestra. </li></ol></li><li> Visualice los cortes individuales o la muestra en tres dimensiones para ver lo que la muestra se ve como en el interior.</li></ol> 6. Visualización de Datos y Procesamiento <ol><li> Utilice uno de una multitud de paquetes de software de procesamiento de imágenes comerciales y de código abierto disponible para la visualización y análisis de datos. 22, 23 </li><li> Al abrir la pila de imágenes reconstruidas con el software que desee, crear orthoslices para mostrar la xy, xz, yz y perspectivas de los datos reconstruidos. </li><li> Pan a través de estas imágenes y la búsqueda de características de interés, como el de las dendritas de litio se muestra en la Figura 2. </li><li> A continuación, utilice la segmentación (etiquetado digital) y las herramientas de renderizado 3D para hacer que la característica de interés en tres dimensiones. </li><li> Para digitalmente segmento de la imagen, cree un campo de etiqueta y el uso de herramientas de umbral para seleccionar regiones de la muestra correspondiente a un material. </li><li> Para volver a crear una imagen como la que se muestra en la Figura 2B, etiquetar los píxeles de litio oscuro y el luminoso píxeles electrolito. Etiquetar el litio contenida en eldendrita por separado de los electrodos superior e inferior de litio. <ol><li> Render del litio dendríticas en naranja y el electrolito de polímero en azul. Render los electrodos de metal de litio superior e inferior en gris y ajustar el valor de transparencia para revelar el litio dendríticas naranja. Gire esta reconstrucción tridimensional para ver la estructura desde muchas perspectivas. </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.

Microtomografía de rayos X duro es especialmente adecuado para muestras sensibles al aire, al igual que muchos materiales electroquímicamente activos, ya que los rayos X pueden penetrar a través de material de la bolsa protectora, permitiendo de imágenes fácil de la muestra sin exposición al aire. Tal vez la más valiosa característica de esta técnica de imagen es que los rayos X penetran permiten al usuario ver el interior de la muestra sin destruirlo. La mayoría de las técnicas de imagen comunes, como la mic...

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.

Cuando las células de litio-litio simétricos descritos anteriormente se ciclan a 90 ° C, la respuesta de tensión se parece a la que se muestra en la Figura 1. Eventualmente, las dendritas de litio crecerán a través del electrolito y causar la célula falle por cortocircuito. Cuando esto sucede, la respuesta de tensión a la corriente aplicada se desplegará a 0,00 V. Las dendritas, como la que se muestra en la Figura 2 aparece en muestras que han ...

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.

Análisis de Falla en Baterías Utilizando Microtomografía duro de rayos X a base de Sincrotrón

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 vistas.  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.

Construcción y verificación de las células de la moneda de baterías de ion de litio

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

Investigación

Ingeniería

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.

In Situ de neutrones polvo Difracción Uso de baterías de litio-ion por encargo

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.

Imaging Embalse Condición Pore escala de múltiples fases fluidas Usando Microtomografía de rayos X

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.

La tomografía de rayos X de energía dispersiva de 3D Mapping elemental de nanopartículas individuales

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.

La medición de haz de rayos X coherencia a lo largo de múltiples direcciones Usando 2-D del tablero de damas rejilla de fase

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.

El uso de la radiación del sincrotrón Microtomografía encargado de investigar multi-escala Paquetes microelectrónicos tridimensionales

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.

Protocolo de prueba electroquímica y caracterización de aprótico Li-O<sub&gt; 2</sub&gt; batería

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.

Dinámica de los poros a escala embalse condición de imagen de la Reacción en carbonatos Uso de Sincrotrón Tomografía rápida

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.

La aplicación de rayos X de imagen Crystal Espectroscopía para su uso como un plasma de alta temperatura de diagnóstico

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.