The Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL) 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. Q.L. thanks the China Scholarship Council (CSC) for financial support through the collaboration based on China 111 project No. B13029. R.Q. thanks the support from LBNL LDRD program. S.S. and Z.Z. thank the support from the ALS Doctoral fellowship.

1. Experimental Planning
Note: While sXES could be performed with lab-based equipment, sXAS and RIXS are synchrotron-based experiments, which requires access to the beamtime of a synchrotron facility. The procedure for applying for beamtime and running experiments could be different at different facilities, but they all follow a similar basic procedure.
<ol>
	<li>Check the facility website for the beamline directory (e.g., https://als.lbl.gov/beamlines/), or contact the scientists i...

<ol>
	<li>Armand, M., 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=Building+better+batteries.">Building better batteries.</a> Nature. 451 (7179), 652-657 (2008).</li><li>Yang, Z., 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=Electrochemical+energy+storage+for+green+grid.">Electrochemical energy storage for green grid.</a> Chem Rev. 111 (5), 3577-3613 (2011).</li><li>Dunn, B., Kamath, H., 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=Electrical+energy+storage+for+the+grid:+a+battery+of+choices.">Electrical energy storage for the grid: a battery of choices.</a> Science. 334 (6058), 928-935 (2011).</li><li>Ellis, B. L., Lee, K. T., Nazar, L. 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B. 25 (1), 17104 (2016).</li><li>Yang, W., 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=Key+electronic+states+in+lithium+battery+materials+probed+by+soft+X-ray+spectroscopy.">Key electronic states in lithium battery materials probed by soft X-ray spectroscopy.</a> Journal of Electron Spectroscopy and Related Phenomena. 190, 64-74 (2013).</li><li>Qiao, R., Yang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactions+at+the+electrode-electrolyte+interfaces+in+batteries+studied+by+quasi-in-situ+soft+x-ray+absorption+spectroscopy.">Interactions at the electrode-electrolyte interfaces in batteries studied by quasi-in-situ soft x-ray absorption spectroscopy.</a> Journal of Electron Spectroscopy and Related Phenomena. , (2017).</li><li>Lin, F., 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=Synchrotron+X-ray+Analytical+Techniques+for+Studying+Materials+Electrochemistry+in+Rechargeable+Batteries.">Synchrotron X-ray Analytical Techniques for Studying Materials Electrochemistry in Rechargeable Batteries.</a> Chem Rev. , (2017).</li><li>Liu, X., 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=Why+LiFePO4+is+a+safe+battery+electrode:+Coulomb+repulsion+induced+electron-state+reshuffling+upon+lithiation.">Why LiFePO4 is a safe battery electrode: Coulomb repulsion induced electron-state reshuffling upon lithiation.</a> Phys Chem Chem Phys. 17 (39), 26369-26377 (2015).</li><li>Liu, G., 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=Polymers+with+tailored+electronic+structure+for+high+capacity+lithium+battery+electrodes.">Polymers with tailored electronic structure for high capacity lithium battery electrodes.</a> Adv Mater. 23 (40), 4679-4683 (2011).</li><li>Wu, 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=Toward+an+Ideal+Polymer+Binder+Design+for+High-Capacity+Battery+Anodes.">Toward an Ideal Polymer Binder Design for High-Capacity Battery Anodes.</a> Journal of the American Chemical Society. 135 (32), 12048-12056 (2013).</li><li>Wang, 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=Rhombohedral+prussian+white+as+cathode+for+rechargeable+sodium-ion+batteries.">Rhombohedral prussian white as cathode for rechargeable sodium-ion batteries.</a> J Am Chem Soc. 137 (7), 2548-2554 (2015).</li><li>Qiao, 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=Distinct+Solid-Electrolyte-Interphases+on+Sn+(100)+and+(001)+Electrodes+Studied+by+Soft+X-Ray+Spectroscopy.">Distinct Solid-Electrolyte-Interphases on Sn (100) and (001) Electrodes Studied by Soft X-Ray Spectroscopy.</a> Advanced Materials Interfaces. 1 (100), (2014).</li><li>Shan, X., 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=Bivalence+Mn5O8+with+hydroxylated+interphase+for+high-voltage+aqueous+sodium-ion+storage.">Bivalence Mn5O8 with hydroxylated interphase for high-voltage aqueous sodium-ion storage.</a> Nat Commun. 7, 13370 (2016).</li><li>Qiao, R., Chuang, Y. 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href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+evidence+of+gradient+Mn(II)+evolution+at+charged+states+in+LiNi0.5Mn1.5O4+electrodes+with+capacity+fading.">Direct evidence of gradient Mn(II) evolution at charged states in LiNi0.5Mn1.5O4 electrodes with capacity fading.</a> Journal of Power Sources. 273, 1120-1126 (2015).</li><li>Wu, 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=Modification+of+Transition-Metal+Redox+by+Interstitial+Water+in+Hexacyanometallate+Electrodes+for+Sodium-Ion+Batteries.">Modification of Transition-Metal Redox by Interstitial Water in Hexacyanometallate Electrodes for Sodium-Ion Batteries.</a> Journal of the American Chemical Society. , (2017).</li><li>Liu, X., et al. <a target="_blank" 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The formidable challenge of improving the performance of energy storage materials requires advances of incisive tools to directly probe the chemical evolutions in battery compounds upon electrochemical operation. Soft X-ray core-level spectroscopy, such as sXAS, sXES, and RIXS, is a tool-of-choice for detecting the critical valence states of both the anions and cations involved in LIBs and SIBs.
Core-level spectroscopy techniques involve the strong excitation of core electrons to unoccupied st...

Developing high-performance batteries is one of the crucial requirements for realizing modern energy applications with environmentally benign resources and devices. Developing high-efficiency, low-cost, and sustainable energy storage devices has become critical for both electric vehicles (EVs) and the electric grid, with a projected energy storage market expansion of ten times in this decade. The ubiquitous Li-ion battery (LIB) technology remains a promising candidate for high energy-density and high power energy storage solutions1, while Na-ion batteries (SIBs) hold the promise of realizing low-cost and stable storage for green-grid applications2. However, the overall level of battery technology is well below what is required to meet the need of this new phase of mid-to-large scale energy storage1,3.
The pressing challenge of developing high-performance energy-storage system arises from the complex mechanical and electronic characteristics of the battery operations. Extensive efforts have focused on material synthesis and mechanical properties. However, the evolution of the chemical states of particular elements in battery electrodes is often under active debate for newly developed battery materials. In general, both LIBs and SIBs operate with evolving electronic states triggered by the transportation of the electrons and ions during the charge and discharge process, leading to the oxidation and reduction (redox) reactions of specific element(s). As the bottleneck for many performance parameters, battery cathodes have been paid much attention in research and developments4,5. A practical battery cathode material is often a 3d transition-metal (TM) oxide with particular structural channels for ion diffusion. Conventionally, the redox reaction is limited to the TM elements; however, recent results indicate that oxygen could possibly be utilized in reversible electrochemical cycling6. The redox mechanism is one of the most critical pieces of information for understanding an electrochemical operation, and a direct probe of the chemical states of battery electrodes with elemental sensitivity is thus highly desirable.
Synchrotron-based, soft X-ray spectroscopy is an advanced technique that detects the valence electron states in the vicinity of the Fermi level in battery materials7. Because of the high sensitivity of soft X-ray photons to the electrons of a specific element and orbital, soft X-ray spectroscopy could be utilized as a direct probe of the critical electron states in battery electrodes8, or at the interfaces in batteries9. Furthermore, compared with hard X-rays, soft X-rays are lower in energy and cover excitations of the low-Z elements, e.g., C, N, O, and of the 2p-to-3d excitation in the 3d TMs10.
The excitations of soft x-ray spectroscopy first involve electron transitions from a particular core state to an unoccupied state by absorbing energy from soft X-ray photons. The intensity of such soft X-ray absorption spectroscopy thus corresponds to the density of state (DOS) of the unoccupied (conduction-band) states with the existence of the excited core-holes. The X-ray absorption coefficient can be measured by detecting the total number of photons or electrons emitted during the decay process. The total electron yield (TEY) counts the total number of emitted electrons, and is thus a photon-in-electron-out (PIEO) detection mode. TEY has a shallow probe depth of several nanometers, and therefore is relatively surface sensitive, due to the shallow escape depth of electrons. However, as a photon-in-photon-out (PIPO) detection mode, the total fluorescence yield (TFY) measures the total number of emitted photons in the sXAS process. Its probe depth is about hundreds of nanometers, which is deeper than that of TEY. Due to the difference in probe depths, the contrast between TEY and TFY could provide important information for a comparison between the surface and bulk of the material.
sXES is a PIPO technique, corresponding to the decay of the exited state to fill the core hole, leading to the emission of X-ray photons at characteristic energies. If the core electron is excited to the continuum electron state far away from the sXAS threshold, it is a non-resonant X-ray fluorescence process corresponding to the decay of occupied (valence-band) electrons to the core holes, i.e., sXES reflects the DOS of the valence-band states. Otherwise, if the core electron is resonantly excited to exactly the absorption threshold, the resulting emission spectra feature strong excitation energy dependence. For this case, the spectroscopy experiments are denoted as resonant inelastic x-ray scattering (RIXS).
Because sXAS and sXES corresponds to the unoccupied (conduction-band) and occupied (valence-band) electron states, respectively, they provide complementary information on the electron states involved in the reduction and oxidation reactions in the battery electrodes upon electrochemical operation11. For low-Z elements, especially C12,13, N14, and O15,16,17, sXAS has been widely used for studying the critical electron states corresponding to both the electron transfer12,13 and chemical compositions15,16,17. For 3d TMs, sXAS of TM L-edges has been successfully demonstrated to be an effective probe of the TM redox reactions of V18, Mn19,20,21,22,23, Fe23,24,25,26, Co20,27, and Ni20,28. Because the TM-L sXAS features are dominated by the well-defined multiplet effect, which are sensitive to the different TM oxidation18,19,20,21,22,24,25,26,27,28 and spin states14,29, the TM sXAS data could enable even quantitative analysis of the TM redox couples in LIB and SIB electrodes27.
Compared with the popular employment of sXAS for battery material studies, RIXS is less often utilized due to the complexity of both the experiments and data interpretation for obtaining meaningful information related to battery performance10. However, due to the extremely high chemical-state selectivity of RIXS, RIXS is potentially a much more sensitive probe of the chemical state evolution in battery materials with inherent elemental sensitivity. Recent sXES and RIXS reports by Jeyachandran et al., have showcased the high sensitivity of RIXS to specific chemical configurations in the ion-solvation systems beyond sXAS30,31. With the recent rapid developments of high-efficiency RIXS systems32,33,34, RIXS has quickly shifted from a fundamental physics tool to a powerful technique for battery research, and occasionally becomes the tool-of-choice for specific studies of both the cation and anion evolution in battery compounds.
In this work, the detailed protocols for sXAS, sXES, and RIXS experiments are introduced. We cover the details of experimental planning, technical procedures for carrying out experiments, and more importantly, data processing for different spectroscopic techniques. Furthermore, three representative results in battery material studies are presented to demonstrate the applications of these three soft X-ray spectroscopy techniques. We note that the technical details of these experiments could be different at different end-stations and/or facilities. Additionally, ex-situ and in-situ experiments have very different setup procedures on sample handling due to the stringent requirements of ultra-high vacuum for soft X-ray spectroscopy35. But the protocol here represents the typical procedure and could serve as a common reference for soft X-ray spectroscopy experiments in various experimental systems at different facilities.

<table border="0" cellpadding="0" cellspacing="0" style="width:833px;" width="834">
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	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Material</td>
			<td style="width:144px;"></td>
			<td style="width:119px;"></td>
			<td style="width:355px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Electrode active materials</td>
			<td style="width:144px;">various</td>
			<td style="width:119px;"></td>
			<td>Synthesized in-house or obtained from various suppliers.</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Lithium foil</td>
			<td style="width:144px;">Sigma-Aldrich</td>
			<td>320080</td>
			<td style="width:355px;">Anode for half cells. Store and handle in an inert atmosphere glovebox under Ar. (www.sigmaaldrich.com)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Sodium foil</td>
			<td style="width:144px;">Sigma-Aldrich</td>
			<td style="width:119px;">282065</td>
			<td style="width:355px;">Anode for half cells. Store and handle in an inert atmosphere glovebox under Ar. (www.sigmaaldrich.com)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Electrolyte solutions</td>
			<td style="width:144px;">BASF</td>
			<td style="width:119px;">Contact vendor for desired formulations</td>
			<td style="width:355px;">http://www.catalysts.basf.com/p02/USWeb-Internet/catalysts/en/content/microsites/catalysts/prods-inds/batt-mats/electrolytes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Synthetic flake graphite</td>
			<td style="width:144px;">Timcal</td>
			<td style="width:119px;">SFG-6</td>
			<td style="width:355px;">Conductive additive for electrodes. (www.timcal.com)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Indium foil</td>
			<td style="width:144px;">Sigma-Aldrich</td>
			<td style="width:119px;">357308</td>
			<td style="width:355px;">Used if collecting Carbon and Oxygen signals of power samples</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Argon gas</td>
			<td style="width:144px;">Air Products</td>
			<td style="width:119px;">Custom order, contact vendors</td>
			<td style="width:355px;">Argon used to fill glovebox where to assemble and store air-sensitive samples. (http://www.airproducts.com/products/gases.aspx)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Eqiupment</td>
			<td style="width:144px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">CCD</td>
			<td style="width:144px;">iKon-L</td>
			<td style="width:119px;">DO936N</td>
			<td style="width:355px;">Used to capture the emission photons when carrying out the sXES or RiXS experiment (http://www.andor.com/scientific-cameras/ikon-xl-and-ikon-large-ccd-series/ikon-l-936)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Inert atmosphere glovebox</td>
			<td style="width:144px;">MBRAUN</td>
			<td style="width:119px;">MB200B</td>
			<td style="width:355px;">Used during air-sensitive samples assembly and storage. (http://www.mbraun.com/products/glovebox-workstations/mb200b-mod)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Battery Charge &#38; Discharge Tester</td>
			<td style="width:144px;">Bio-Logic</td>
			<td style="width:119px;">VMP3</td>
			<td style="width:355px;">Used to electrochemical cycling of battery materials. (https://www.bio-logic.net/en/)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Swagelok cell</td>
			<td style="width:144px;">MTI</td>
			<td style="width:119px;">EQ-HSTC</td>
			<td style="width:355px;">Used to contain the battery for electrochemical cycling</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sample holder</td>
			<td style="width:144px;">manufactured in lab</td>
			<td style="width:119px;"></td>
			<td>Used to hold the samples in the experiment</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Hardware tools</td>
			<td style="width:144px;">various</td>
			<td style="width:119px;"></td>
			<td style="width:355px;">Including tweezers, scissors (used to assemble samples), tongs (used to transfer sample holders), etc.&#160;</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Carbon and Copper tape</td>
			<td style="width:144px;">3M</td>
			<td style="width:119px;">Custom order, contact vendors</td>
			<td>Used to paste the samples onto sample holders</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Igor Pro</td>
			<td style="width:144px;">WaveMetrics</td>
			<td style="width:119px;">7.06</td>
			<td style="width:355px;">Used to process the experiment data. (https://www.wavemetrics.com/index.html)</td>
		</tr>
	</tbody>
</table>

elemental-sensitive detection of the chemistry in batteries through soft x-ray absorption spectroscopy and resonant inelastic x-ray scattering

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid based on volatile solar and wind sources. The pressing demand of developing high-performance electrochemical energy storage solutions, i.e., batteries, relies on both fundamental understanding and practical developments from both the academy and industry. The formidable challenge of developing successful battery technology stems from the different requirements for different energy-storage applications. Energy density, power, stability, safety, and cost parameters all have to be balanced in batteries to meet the requirements of different applications. Therefore, multiple battery technologies based on different materials and mechanisms need to be developed and optimized. Incisive tools that could directly probe the chemical reactions in various battery materials are becoming critical to advance the field beyond its conventional trial-and-error approach. Here, we present detailed protocols for soft X-ray absorption spectroscopy (sXAS), soft X-ray emission spectroscopy (sXES), and resonant inelastic X-ray scattering (RIXS) experiments, which are inherently elemental-sensitive probes of the transition-metal 3d and anion 2p states in battery compounds. We provide the details on the experimental techniques and demonstrations revealing the key chemical states in battery materials through these soft X-ray spectroscopy techniques.

The sample holder and pasted samples are shown in Figure 1. Figure 7a is a typical RIXS image collected at a particular excitation energy with the spectrometer set to the interested edges. The image shown here was collected on a battery electrode material, LiNi0.33Co0.33Mn0.33O2, with an excitation energy of 858 eV and the detector set at about 500-900 eV range to cover...

Watch this Scientific Journal Video about Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering at JoVE.com

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering

Here, we present a protocol for typical experiments of soft X-ray absorption spectroscopy (sXAS) and resonant inelastic X-ray scattering (RIXS) with applications in battery material studies.

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid ...

The overall goal of this protocol is to apply soft X-ray absorption spectroscopy and resonant inelastic X-ray scattering to battery material studies. This method is about utilizing soft X-ray spectroscopy, including X-ray absorption and resonant inelastic X-ray scattering, the so-called RIXS, as unique tools to answer the key questions in battery field. The main advantage of this technique is it can directly probe the chemical reactions in various battery material and develop this field beyond the conventional trial-and-error approach.Though this method can provide insight into battery materials, it can also be applied to other systems, such as catalysts, solar cells, and semiconductors. Visual demonstration of this method is critical as synchrotron based soft X-ray spectroscopy is difficult to learn without it. This protocol provides a detailed visual example of a typical experiment.To begin, cut the battery material samples to fit the sample holder, ensuring that each sample is larger than the beam spot. Fix the samples on the sample holder with double-sided conductive tape. For some powder samples, use indium foil to stick if necessary.Then, vent the sample load lock with nitrogen gas. Use a sample grabber, such as large tweezers, to load the sample holder into the load lock. Close and evaluate the load lock.Once the load lock pressure is sufficiently low, open the valve between the load lock and the main chamber. Using the transfer arm, transfer the sample holder to the main manipulator in the main chamber. Close the valve to the load lock, then open the valve between the main chamber and the beam line.Locate the beam spot by observing visible light fluorescence on a reference sample or on a phosphor applied to the sample holder. Position a sample in the beam spot using the sample manipulator controls. Connect the X-ray beam flux monitor signal cables to the measurement computer.Adjust the beam line monochromator slits to tune the energy resolution of the incident X-ray beam. Then, set the incident beam energy to the absorption edge of the element or elements of interest. Fix the monochromator mechanism in place.Measure the beam flux intensity and identify the undulator gap value that provides the maximum possible beam flux. To begin the sXAS data collection process, ensure that the sample current signal used to measure the total electron yield is directed to the measurement computer. Turn on the power supplies and controllers of the electron multiplier or photo diode used to measure the total fluorescence yield.Ensure that the signal is directed to the computer. Then, in the data acquisition software, select Single Motor Scan. Open the Scan Setup menu and set the incident X-ray photon scan range to span the sXAS edge of interest.Click Start Scan to simultaneously record the total electron yield, total fluorescence yield, and the beam flux while scanning the incident X-ray photon energy. Follow the same beam alignment and data collection procedure to acquire sXAS data for additional samples. If a reference sample has been scanned, adjust the scan range accordingly for any shift observed in the sXAS values.After collecting sXAS data, turn on the spectrometer for the sXES and RIXS system and cool down the soft X-ray detector, then open the motor controls. Set the spectrograph parameters to cover the energy range of the elements and edges of interest. Next, select CCD Instrument Scan and open the Scan Setup.For sXES, set a single value about 20 to 30 electron volts above the calibrated sXAS absorption edge. For RIXS, set the scan range to span the sXAS absorption edge. Select Apply Cosmic Ray Filter so that cosmic ray signals will be removed from the raw RIXS 2D images after initial data collection.Start the scan to collect fluorescent signals in 2D image form for each excitation energy. This RIXS image was collected from a lithium-ion battery material sample over the energy range of the Oxygen-K edge and the Manganese, Cobalt, and Nickel-L edges. A full range sXES covering all four edges simultaneously was collected in 10 seconds.A RIXS map of the Nickel-L edge was generated from the raw RIXS image data. Analysis of this map showed that the Nickel-L RIXS features were dominated by d-d excitations. Transition metal redox states in sodium-ion and lithium-ion battery materials were analyzed by quantitative fitting of sXAS spectra.The surface manganese valence distribution in layered sodium-manganese oxide electrodes at different electrochemical states was determined by quantitative fitting of sXAS spectra to a linear combination of Manganese II, III, and IV cation reference spectra. The redox process of a spinel lithium-nickel-manganese oxide electrode was identified as sequential single-electron transfers by a similar quantitative fitting approach using total fluorescence yield. Intermediate charge states of lithium-iron-phosphate electrodes were identified by quantitative fitting based on sXAS spectra of the electrodes at 0%and 100%charge.We have been making efforts to utilize synchrotron-based soft X-ray spectroscopy to characterize battery materials with unprecedented results. After its development, the technique paved the way for the researchers in the field of battery materials. The researchers can use it to explore the fundamental mechanula of the battery material.After watching this video, you should have a good understanding of how to perform soft X-ray spectroscopy at a synchrotron light source.

elemental-sensitive-detection-chemistry-batteries-through-soft-x-ray

Research

JoVE Journal

Chemistry

12.5K visualizações.  Stanford University. The overall goal of this protocol is to apply soft X-ray absorption spectroscopy and resonant inelastic X-ray scattering to battery material studies. This method is about utilizing soft X-ray spectroscopy, including X-ray absorption and resonant inelastic X-ray scattering, the so-called RIXS, as unique tools to answer the key questions in battery field. The main advantage of this technique is it can directly probe the chemical reactions in various battery material and develop this field beyon...