Agilent Technologies, Inc. (A) Earnings Call Transcript & Summary

Hello, everyone. Welcome to today's live broadcast. Elemental Analysis of Lithium Ion Battery Cathode and Anode Precursor Chemicals, Lithium Iron Phosphate and Silicon Graphite. I'm Bob Alberta, Special Projects Director for Spectroscopy and I'll be your moderator for today's event. We are pleased to bring you this webcast presented by Spectroscopy and sponsored by Agilent. I would now like to share a quick statement from our sponsor. Agilent is a leader in life sciences, diagnostics and applied chemical markets. The company provides laboratories worldwide with instruments, services, consumables, applications and expertise, enabling customers to gain the insights they seek. Agilent's expertise and trusted collaboration give customers the highest confidence in the company's solutions. We have a few important announcements before we begin. This webcast is designed to be interactive and we encourage you to ask questions during the event. You can submit your questions by typing them in the Q&A box, which can be found at the bottom of the video player. You can also enlarge the slide window by clicking on the small icon in the bottom right corner of the media player. The slides will advance automatically during the event. And if you have any technical problems viewing or hearing this presentation, please click on the question mark help widget in the top right of your presentation window. I would now like to introduce today's speakers. We are so pleased to welcome Dr. Sima Singha and Dr. Emma Qi. Sima is an Application Scientist at Agilent Technologies, supporting the ICP-OES, MP-AES and AA instruments. She has over 15 years of hands-on experience in the field of atomic spectroscopy. Before joining Agilent in 2017, she managed an agricultural chemistry laboratory for the analysis of water, soil and plant tissue samples using an ICP-OES. She received a PhD degree in chemistry from the University of Illinois at Chicago and has numerous peer-reviewed publications. Emma is an application scientist working at Agilent Technologies in the optical atomic spectroscopy group. Emma has focused her last 12 months on streamlining the preparation and elemental analysis of lithium-ion battery materials using ICP-OES. Thank you both for joining us today. Please take it away.

Thanks for inviting us today to talk about lithium-ion battery cathode and anode material. In the first part of the webinar, I will talk about determination of elemental impurities in lithium iron phosphate cathode materials via ICP-OES. I will discuss about lithium-ion battery industry chain and where elemental analysis fits into this industry. Then I will focus on to the cathode materials and workflow for lithium iron phosphate sample analysis on ICP-OES. Finally, I'll talk about the challenges and solutions for sample preparation and method development and then show you some results from some real life sample analysis on lithium iron phosphate [indiscernible]. Lithium-ion battery industry chain has four segments: upstream, midstream, downstream and recycling. Elemental analysis is done in step #1, 2 and 4. In the upstream, we do impurity testing on raw materials. And in the midstream, cathode materials, anode materials and electrolytes are tested for quality control. A lot of research and development is also done at this part to create a better battery. And once the batteries are spent, the recycling is done to collect the metal and use those in the upstream again. There are various cathode materials used in the lithium-ion battery industry. Two most widely used cathode materials are lithium iron phosphate and ternary materials. Ternary materials are lithium plus 3 other elements, for example, lithium, nickel, cobalt, manganate or lithium, nickel, cobalt, aluminate. If I compare the characteristics of the LFP and ternary materials in terms of energy density, safety, charging efficiency, life cycle and cost, lithium iron phosphate cathodes win in 3 categories. They're safer, life cycle is better and cost is cheaper. So that makes them very popular in the lithium battery industry. Now that you have a better understanding of the lithium-ion battery industry and different cathode materials. Let's talk about workflow in the lab. Lithium iron phosphate samples will be in solid form. And you have to turn them into the liquid form before you analyze them on ICP. So we use the microwave digester and we took 0.1 gram of sample and added 6 milliliter of HCl and 2 milliliter of nitric acid and digested the samples at 200 Celsius for 20 minutes. The final volume of the samples were 50 millimeter. So that gives about 500x dilution factor. We didn't see any precipitate or undigested material in the sample, but if you see any, don't forget to filter the sample before they are aspirated in the ICP-OES instrument. The next step in the workflow is method development. If you look at the lithium iron phosphate sample composition, you will see that lithium, iron and phosphate concentrations are very high in the samples and there are very trace levels of impurities. So these samples are very challenging because they have high dissolved solids or salts. And there are high and low concentrations of elements coexisting in the same sample. There are easily ionizable elements at high concentrations and low concentrations. For example, you are looking for trace elements such as sodium and potassium in presence of high concentration of lithium. There will be spectral interferences from iron and phosphorus and there will be carryover for contamination. I will discuss about how to overcome these challenges using various instrument features, internal standards and accessories in next 3 slides. The 5800 VDV ICP-OES is a dual view system with a vertical torch. The vertical torch can handle very high total dissolved solids with less maintenance. Also, the torch is easy to install using the torch loader. The analyst doesn't have to connect any gas tubings or perform torch optimization or alignment. Everything is automatically done once you close the torch loader. That saves time. The optics in the 5800 ICP-OES are optimized to provide you better detection limits and more stability. A default sample introduction system was used on the ICP-OES or the LFP sample types. We recommend using a fully demountable torch because lithium tends to degrade the outer tube of torch overtime. In that case, you want to replace the outer tube, you don't have to replace the whole torch. We added an accessory called Argon humidifier to the sample introduction system to keep the nebulizer device. Because the high salt samples tend to form some deposits at the tip of the nebulizer and you might see some blockage when we need this type of sample analysis. Also to handle the effect of easily ionizable elements on certain elements, for example, sodium and potassium. We added rubidium as an internal standard in addition to [indiscernible]. To remove carryover and maximize sample throughput, a smart feature of the instrument called Intelligent Rinse was used. Intelligent Rinse has a maximum rinse time and it monitors the analytes in the rinse solution and decide how much rinse time it needs after [ rinse ] solution. For a very clean solution, Intelligent Rinse might move on to the next sample without using the maximum rinse time, thus saving the Argon Gas and the rinse solution and increasing sample throughput. During method development, the sample per screen using IntelliQuant. IntelliQuant is a semi-quantitative analysis and it can analyze up to 70 elements using peak elevated methods. IntelliQuant shows the data as a heat map, pie graph or a bar graph. The heat map of lithium iron phosphate sample shows the approximate concentrations of the primary salt element and some traces, the numbers in the parenthesis are in ppm or milligram per liter. The color coding is red means high concentration, orange is medium concentration and light yellow to yellow is no concentration. IntelliQuant can also identify on nonspectral interferences using some kind of data analytics. In this lithium iron phosphate sample, IntelliQuant clearly identified that chromium 267-nanometer wavelength is interfered by phosphorus. So moved on to the second best wavelength that is 205.560 nanometer and took the data from that wavelength. With the knowledge of the approximate analytic concentration and possible interferences from IntelliQuant, we are now ready to set up our quantitative analysis. This method was set up in Dual View where all the trace elements were analyzed in axial mode and the primary salt elements were analyzed in radial mode. The method parameters were mostly default, except for axial view, we used a little bit more RF power. It was 1.3 kilowatt to get a little bit more sensitivity from the trace elements in axial view. All the trace elements were calibrated from 0 to 500 VDV in axial view. And the correlation coefficients were greater than 99.99% for all the elements. The calibration ranges for lithium, iron and phosphorus in radial view were in the high [indiscernible] to match the sample concentrations and also to avoid any further sample dilution. So in this Dual View method, we were able to analyze for very low ppb concentration of the traces and high ppm concentration of the salt element. A few slides ago, I talked about how IntelliQuant detected that the primary chromium line 267 nanometer at interference from -- by phosphorus. If I still want to use this chromium line, I have to remove the spectral interferences and to remove the spectral interference, I used a method called Fast Automated Curve-fitting Technique or FACT. FACT is a spectrum deconvolution technique. And in order to do FACT, you have to analyze 3 solutions here, a black and a pure analyte solution that's chromium and a pure interference solution, that's phosphorus. And you lock them into their FACT model for chromium 267-nanometer and the FACT model will subtract the phosphorus interference from the [indiscernible] peak. FACT can increase the data accurately by removing the spectral interferences. The detection limits for the LFP method were studied in the blank and the salt matrix with the 5 ppb [indiscernible] the trace elements. All the traces had some ppb to single-digit ppb detection limit, showing high sensitivity of the instrument. In the last column, the sample results are dilution adjusted. Ensure the method is successful in analyzing low ppb to high ppm concentration with a single sample preparation or dilution. To validate the method, a sample was spiked with 100 ppb of the trace elements predigestion, despite recoveries were within plus or minus 10% even in the high salt concentration. The instrument was able to eliminate the matrix effect very efficiently. The instrument stability is an important factor to achieve reproducibility of the data. This graph shows the 9-hour stability study of 100 ppb CCV. The recoveries were within plus or minus 10% and RSDs were below 2.3% for all the traces. To show the ruggedness and stability of the instrument, 100 ppb spike sample was also [indiscernible] after 10 samples for 9 hours. The RSDs were below 2.2%, and there is no instrument drift from the high salt matrix. In total, the method analyzed 236 solutions with excellent [indiscernible] and without any kind of recalibration. So to summarize on the results, I would say that Agilent 5800 ICP-OES was able to handle the challenging lithium iron phosphate samples with ease. Various smart features in the hardware and software were used to create a robust method that give us very low detection limit, while linear dynamic rate, high producibility and accuracy. If you are trying to set up the workflow or elemental analysis on different types of lithium-ion battery samples, these are some publications that might be helpful. You can download them by scanning the bar code or searching for the publication numbers in red. Thanks for listening in. Up next, Emma will present the silicon carbon Anode material.

My talk is about the determination of elemental impurities in silicon carbon and materials for lithium-ion batteries by ICP-OES. In this presentation, I'm going to talk about why we analyze silicon carbon Anode materials and what the challenges are there. And then I'm going to outline the methods for sample preparation and also the instrumentation. And then in the results section, I will talk about how the Agilent 5800 ICP-OES with the ICP expert software is able to meet the challenges and offers good sensitivity, accuracy and stability for elemental impurity analysis of lithium-ion battery Anode materials. At the end, it's a brief summary. The global lithium-ion battery market is fast growing in recent years. Mostly driven by the soaring demand for electric cars, large-scale energy storage as well as small personal electronic devices. The Anode is an essential component of a lithium-ion battery, making up 5% to 15% of lithium-ion battery costs. Conventional, commercial lithium-ion batteries primarily use graphite-based anodes. The advantages of graphite as Anode materials are its availability, excellent electronic conductivity properties and low cost. The drawbacks include decreased rate capacity, low specific capacity as well as safety risks. To overcome the downsize of the current Anode materials, researchers and industries have been attempting to find alternative Anode materials with higher performance over the years. Among the potential alternative Anode materials being researched, silica has stood out as a potential, very promising Anode material with its very high theoretical storage capacity, working potential and natural abundance. Overcoming the biggest drawbacks of silicon, namely volume expansion and low conductivity, the most promising silicon anode material is the silicon carbon nanocomposite which benefits from the very high volumetric and specific capacity of the silicon, where the carbon matrix can handle volume fluctuation, maintains the structural integrity and electrical stability of the material. Production of silicon carbon Anode materials has advanced to commercialization recently. It is claimed the new materials at 5x the capacity of graphite and affords up to 50% more energy density than the conventional graphite for lithium-ion batteries. Whether it's conventional or the new generation Anode materials, it is important for relevant industries which is developers, suppliers and users of the materials to use robust testing methods for quality control because the quality of Anode materials is critical to the overall performance of the final products. Elemental impurities can be detrimental to lithium-ion battery capacity, rate performance, cycle stability, et cetera. As a lithium producer of Anode materials, China has issued two national standards, one for graphite Anode materials and the other is for silicon carbon, both recommended standards require the analysis of trace elements such as iron, sodium, chromium, copper, et cetera, using ICP-OES following microwave digestion of the samples. Based on this methodology in the standards, we analyzed 25 elements in the graphite and the mixture of the graphite and silicon at 9:1 mass ratio, which are representing a graphite Anode material and the silicon carbon Anode material, respectively. Using the Agilent 5800 VDV ICP-OES. To analyze graphite and silicon carbon Anode materials using ICP-OES, is not without its challenges. The biggest challenge is related to the complex sample matrix due to the nature of the samples and digestion methods used, which can lead to high background signal and physical and spectral interferences. Another challenge is related to the very low but varied impurity levels in the samples. In the [ GB ] standards, graphite fixed carbon is specified as high as 99.7% to 99.95% or higher while the silicon mass fractions specified for silicon carbon materials are between 2% and 40%. This means the instruments need to be able to have high sensitivity and wide working range as well as being able to handle high complex sample matrix. On top of these challenges, the undissolved solids in the microwave digestive samples and the process to ensure their fully removal while not introducing any new contaminations or causing sample loss is quite testing for the operators but the process is vital for the quality of the results. Any undissolved solid particles may block the nebulizer or affect sample matrix during ICP-OES analysis. With these challenges in mind, our answer is the advanced Agilent 5800 ICP-OES together with its smart features in the ICP expert software. It is well designed and equipped to handle the complex sample matrix of lithium-ion battery Anode materials. The VistaChip detector of the 5800 ICP-OES offers fast simultaneous measurement of both major and trace elements offers automatic background correction as well as effective interference measurement. In the ICP expert software, the default fitted background correction, FBC can accurately correct spectral interferences and improve data accuracy. Also in the ICP expert software, the unique smart feature of IntelliQuant screening. It simplifies method development by performing a quick semi-quantitative scan of the sample, detecting spectral interferences and helping with wavelength selection. In the following slides, I'm going to go into more details about how some of these features can help with the Anode material analysis. This slide shows the process of sample preparation for ICP-OES analysis. The method was based on the microwave digestion method outlined in the 2 GB methods for Anode materials. 99.99% graphite and the mixture of this graphite with a 99% silicon at 9:1 mass ratio were used to represent graphite and silicon carbon anode material, respectively. 1 gram of the sample was accurately weighed on the balance before being added to a dry clean microwave digestion tube. After thoroughly mixed in aqua regia, which is hydrochloric acid and nitric acid at 3:1 model ratio the samples were then digested using a MARS 6 microwave digestion system at 200 degrees holding for 30 minutes. After digestion, the content in the digestion vessel was transferred to a 50 [ mL ] tube made up to volume. The solution was then filtered through a 0.45 micron disc filter to remove undissolved particles and Agilent 5800 ICP-OES equipped with an SPS for autosampler was used for subsequent analysis. Blank control samples were also processed and analyzed following the same procedure. All solutions were prepared in triplicate. To analyze the prepared samples on ICP-OES, the Agilent 5800 ICP-OES instrument was controlled using the ICP expert 7.6 software. The instrument was fitted with a Seaspray glass concentric nebulizer, double pass cyclonic three chamber and an EzyFit fully demountable torch with 1.8 millimeter quartz injector. Sample introduction was performed using the Agilent SPS 4 autosampler. Prior to quantitation on ICP-OES to simplify the method development process for quantitation, a unique feature in the Agilent ICP expert software IntelliQuant is a great and a very useful tool that makes the better development process quick and simple. It allows users to run a quick semi-quantitative analysis of a sample by scanning the entire spectral range of up to 70 elements. The results are displayed in a color-coded periodic table heatmap, allowing users to easily see which elements are present and which -- what concentration. The heatmap here shows the semi-quantitative results of a quick IntelliQuant scan of a silicon sample solution. Here, we can see aluminum highlighted in orange is the most abundant element followed by calcium highlighted in dark yellow and some other elements in light yellow. This information is just what we need to decide the concentration range of our calibration standards. The IntelliQuant function also identifies any potential interferences and determines the optimal analysis wavelengths using a star ranking based on potential interferences. This figure on the right shows the prime wavelength for vanadium 292.401 is ranked with just 1 star, hovering the mouse on the red question mark, a message indicates the potential spectral interference of titanium 292.396. The vanadium 309.310 is ranked with 5 stars with a green tick. This informs us the wavelength we can use for vanadium quantitation. The star ranking is very useful with the selection of quantitation wavelength. To run the samples for IntelliQuant, there's no need for prior knowledge of the samples or expertise in spectroscopy with minimal instrument setup required. The operators can spend less time for quantitation method development. A total of 25 elements in our samples were analyzed. Following sample preparation, digested graphite samples were directly analyzed ICP-OES. Silicon carbon samples were diluted 10 times before quantitation so that the higher impurity concentrations were within the working range. Calibrations standard solutions, blood control samples, continuing calibration verification and blank as well as internal standard solutions were all prepared in the same matrix as the samples. Instrument operating conditions were evaluated and optimized based on calibration, linearity and detection limits. Axial viewing mode was used for all 25 elements. And it turns out all the conditions for the instrument default conditions except for the longer rate time to accommodate the low impurity concentrations. This slide shows the working range and linear correlation coefficient for 25 elements at selected wavelength. Note the bigger working range for aluminum and iron when 2 ppm concentration standard was added for both to cover their higher concentrations in the samples which we determined during IntelliQuant screening when we showed in our previous slide. As shown in this table, good linearity was achieved for all 25 elements at selected wavelength. The calibration curve of iron in this figure show a perfect linear calibration coefficient of 1 across 6 calibration points from 5 ppb and to 2 ppm. Iron is an important efficiency indicator for anode as an impurity. The excellent linear dynamic range of the 5800 ICP-OES, we show here allows for accurate detection of higher iron concentrations. So after the samples are analyzed on ICP-OES when it comes to correct interferences from complex sample matrix, there are a number of background correction methods in the ICP expert software, the users can choose. The default option is fitted background correction, FBC, eliminating the need for users input, FBC provides accurate correction of both simple and complex background structures. And the example here shows the FBC accurately models and corrects the spectral interference of OH 327.421 and the copper 327.395. To determine the sensitivity of the ICP-OES instrument, limits of detection and limits of quantitation were measured. 10 blank sample matrix solutions were analyzed. The values presented in this table are the average of 3 results measured on 3 nonconsecutive days and calculated as 1 gram graphite in 50 mL solution. For silicon carbon, the LODs and LOQs are 10x of these values to account for the dilution factor. The high sensitivity of the Agilent ICP-OES instrument is shown by the well below 1 milligram per kilo LODs. For some elements, the values are at ppb level. The excellent low LODs and LOQs are achieved because the Agilent 5800 ICP-OES uses the industry's most advanced freeform optics. The results of impurities in graphite and silicon carbon are shown on the 2 columns on the right. Quantitation of the elements in the 99.99% graphite sample and the silicon carbon sample with 10% silicon and 90% graphite using the Agilent ICP-OES, we're able to detect element concentrations as low as 10 to 100 ppb levels as the values in red shown. This result meets the specifications in the 2 GB methods for elemental impurities in lithium-ion battery Anode materials. Spike recovery tests are an effective way to evaluate the accuracy and reliability of the sample preparation method and all the analytical method, especially when no certified reference materials are available. In our case, the graphite samples were spiked with all 25 elements at 25 ppb or 1.5 -- 1.25 milligram per kilo before microwave digestion. The silicon carbon sample solutions were diluted 10x after microwave digestion and spiked. For calcium, potassium and sodium to higher levels spiked on concentrations, 50 and 100 ppb were also used. Spike recoveries within plus or minus 10% of the expected value were achieved for all spike experiments. The results for graphite at 25 ppb spike concentration are shown in this figure. The good spike recovery results for graphite samples before digestion validated the accuracy of the sample preparation procedure while the spike recovery results for silicon carbon samples after digestion confirm the accuracy of the 5800 ICP-OES method for the analysis of low-level impurities despite the complex sample matrix. To check the stability of the instrument and long-term validity of the calibration 260 measurements were completed over 7.5 hour period without recalibration. A CCB and the CCV sample were measured between every 10 measurements of spiked and unspiked graphite samples. The concentrations of the 19 CCV measurements were brought against time and shown in this figure, the concentrations are within plus/minus 10 of the expected value, while the RSDs for all wavelengths are below 2%, except for potassium and sodium at 3.31% and 3.55%, respectively. The precision of 138 measurements of spiked graphite samples were also excellent over 7.5 hours with RSDs below 5%. The excellent long-term stability can be attributed to the vertical torch configuration and solid-state RF system used in the Agilent ICP-OES which provides excellent plasma robust needs and stability. In conclusion, the Agilent 5800 ICP-OES proved to be well equipped to handle complex sample matrix for routine QC analysis of graphite and silicon carbon Anode materials using methods based on currently available standards for these materials. The unique IntelliQuant feature in the ICP expert software identified spectral interferences and simplifies the method development process for complex samples. The fitted background correction method provides fast and easy, accurate background correction for samples with both simple and complex backgrounds and spectral interferences. The high sensitivity, excellent accuracy and stability of the Agilent 5800 ICP-OES instruments were demonstrated by the very low detection limits, good spike recoveries and long-term stability. This work has now been published as an application note on the agilent.com website. If you're interested, you can scan this QR code and access it on our website. Thank you for your attention.

All right. Thank you both for that informative presentation. Before we get started on the question-and-answer session, I would like to remind our audience how to submit questions. [Operator Instructions] And our first question of the day is, what are the common issues you may encounter during sample preparation and how can you manage them?

So common issues, you may encounter during sample preparations on how to manage them. There are indeed some things and operators should be mindful while preparing the Anode materials for ICP-OES analysis. The first thing can be the constant drifting you find on the balance if you try to weigh the microwave digestion vessel directly on the balance. This is because the static charges on the digestion vessel. The solution is to not weigh the digestion vessel on the balance but to weigh the sample on the balance before transferring to the digestion vessel. Another thing to be mindful is the purity of the SCs for digestion. You may find high impurity levels in the higher SCs. Higher purity agents may be needed. A final thing to be mindful is the filtration of the samples suggested is that a minimum of 0.45 micro filters should be used before ICP-OES analysis. Because if not fully removed, even very fine particles can affect your sample matrix and complicate your results even if they do not block the nebulizer.

For particulate samples, how can you monitor and be alerted of any nebulizer problems like blockage?

So this question is about how to monitor and be alerted of any nebulizer problems like blockage for particulate samples. If any undissolved particles in the samples cause a full blockage of the nebulizer, there's a Neb Alert function in the ICP expert software you can use. To be alerted of the blockage, you can go to file and option. And then in the instrument tab, you can take enable Neb alert and set lower and upper pressure limits. Since the system monitors the nebulizer back pressure if the pressure moves out of the set range an alert will pop up, indicating a potentially blocked nebulizer as soon as it happens rather than finding out later when the QC fails. If the problem with unresolved -- undissolved particles in the samples not severe to cause full blockage of the nebulizer, you can still detect any issues by monitoring the internal standard over time to see if there is a constant drift. To diagnose the problem go to the trend chart of the internal standard on the analysis page.

The GB standards for anode materials specify other groups of elements such as magnetic matter and restricted matter to be determined using ICP-OES. Is your method covering these groups of elements?