Boehmite detection and warning system and concentration indicator for LiB separator manufacturing

Abstract

The invention is entitled Boemite detection and warning system and concentration indicator for LiB separator manufacturing. The invention discloses a method comprising receiving x-ray signals transmitted from an x-ray emitter through a coated separator film. The method further comprises obtaining infrared (IR) signals from the coated separator film. The IR signals comprise two or more spectral components comprising peaks comprising a first peak from the separator film. The method further comprises determining, by a processor, whether a second peak is present and determining whether at least one contaminant / additive is present in a coating present within the coated separator film. The method further comprises calculating, by the processor, a concentration / areal weight of the at least one contaminant / additive and a weight, density, or thickness of the coating.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application Serial No. 63 / 154,249, filed on February 26, 2021, entitled “Boehmite Detection in the Manufacturing of Separators for Battery Coatings,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The aspects disclosed in this invention relate to measuring coating parameters of separators used for battery coating. Background Technology

[0004] Ceramic-coated polyethylene (PE) or polypropylene (PP) separators are crucial components for the performance of lithium-ion batteries (LiB). The separator provides an ion-permeable barrier between the cathode and anode. These membranes are porous and, if uncoated, typically begin to degrade at temperatures around 120°C, leading to short circuits and consequent failure in LiB batteries. The ceramic coating applied to the separator prevents or inhibits shrinkage at elevated temperatures. An example of a ceramic coating is alumina (Al₂O₃). Sometimes, the alumina found on some separator samples is impure, containing contaminants / additives such as boehmite or other binder materials such as polyvinylidene fluoride (PVDF). Ceramic coatings including aluminum applied to the separator surface are known to contribute to increased temperature and chemical stability of the separator up to around 200°C. At higher temperatures, the plastic membrane decomposes, creating a conductive path between the cathode and anode. This leads to a short circuit, thermal runaway, and then an explosion. Summary of the Invention

[0005] This summary is provided to introduce a simplified selection of disclosed concepts, which are further described below in detail with reference to the accompanying drawings. This summary is not intended to limit the scope of the claimed subject matter.

[0006] The disclosed aspects recognize that the alumina coating on the separator can include a mixture of boehmite. The presence of boehmite in the alumina coating or the presence of alumina in the boehmite coating generally affects the physical properties of the separator. For example, boehmite has a density 30% lower than alumina, and its hardness is also significantly lower than that of alumina. In the case of an alumina coating with low-quality alumina, sodium ions and boehmite can leach out and contaminate the battery electrolyte.

[0007] From the battery manufacturer's perspective, it is important to know accurately whether the coating is pure alumina, pure boehmite, or a mixture of the two materials. From a measurement quality control perspective, knowing the composition and density of the coating on a substrate, such as a separator, enables more accurate determination of the coating thickness. To some extent, this is because x-ray, beta particle, or infrared (IR) based absorption measurement techniques are inherently weight measurement techniques, rather than thickness measurement techniques. Thus, it is recognized herein that it would be helpful to be able to detect the presence and amount of boehmite in an alumina coating, or the presence and amount of alumina in a boehmite coating, on a substrate, such as a separator.

[0008] One disclosed aspect includes a measurement apparatus for measuring a coated separator, the coated separator including a stand-alone separator having an aluminum compound coating, including at least one of alumina and boehmite, on at least one surface. The measurement apparatus includes an x-ray sensor including an x-ray source for emitting x-rays, the x-ray source having a high voltage power source coupled to the x-ray source, and an x-ray detector for providing an x-ray signal in response to receiving x-rays transmitted through the coated separator after transmission through the coated separator. The measurement apparatus also includes an IR sensor providing IR signals from the coated separator, the IR signals including at least two spectral components, a first peak for the separator and at least a second peak for boehmite. Another IR spectral component can, but need not, serve as a reference channel.

[0009] A computing device including a processor and a memory is coupled to receive the x-ray signal and the IR signal. The processor is used to determine whether the second peak is present to indicate whether boehmite is present in the aluminum compound coating. The processor is also used to calculate a concentration of boehmite and a concentration of alumina using an algorithm, such as a multivariate regression algorithm, applied to the IR signal and the x-ray signal. Optionally, at least one of a weight of the aluminum compound coating, a density of the aluminum compound coating, and a thickness of the aluminum compound coating can also be calculated.

[0010] In an embodiment, a method includes receiving an x-ray signal transmitted through a coated separator from an x-ray emitter. The method also includes obtaining infrared (IR) signals from the coated separator. The IR signals include two or more spectral components, the spectral components including peaks, the peaks including a first peak from the separator. The method also includes determining, by a processor, whether a second peak is present among the IR peaks. The processor determines whether at least one contaminant or additive is present in a coating present within the coated separator. The method also includes calculating, by the processor, a concentration of an area weight of the at least one contaminant or additive and a weight, a density, or a thickness of the coating.

[0011] In embodiments, a method includes receiving one or more x-ray signals transmitted through a coated barrier film including a ceramic coating. The method also includes obtaining, by a processor, infrared (IR) signals from the coated barrier film, the infrared signals having a first peak for the coated barrier film and a second peak from a contaminant or additive. The method also includes determining, by the processor, whether the second peak from the IR signals is present. The processor determines a type of contaminant or additive present in the ceramic coating within the coated barrier film. The method also includes calculating, by the processor, a concentration of the contaminant or additive from the second peak and a concentration of the ceramic coating from the one or more x-ray signals.

[0012] In embodiments, a system includes an x-ray sensor that receives x-ray signals transmitted through a coated barrier film. The system also includes a top scanner head and a bottom scanner head that obtain infrared (IR) signals from the coated barrier film. The IR signals include two or more spectral components including peaks including a peak for the barrier film. The system also includes a processor that determines whether a second peak is present among the peaks and determines whether a contaminant or additive is present in a coating present within the coated barrier film. The system also includes a memory that stores a calculated concentration or area weight of the contaminant or additive and a weight, density, or thickness of the coating. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 An exemplary measurement device including an x-ray sensor and an IR sensor configured to calculate boehmite concentration and alumina concentration of a coated barrier film (including a barrier film having an aluminum compound coating on at least one surface) and optionally calculate weight and density of the aluminum compound coating and thickness of the aluminum compound coating is depicted according to exemplary aspects.

[0014] Figure 2 Exemplary IR spectra of a pure alumina coated polymer barrier film and an alumina coated polymer barrier film in which the alumina coating includes some boehmite contaminant are shown. The unique IR signature of boehmite, which is an absorption peak at 3.05 microns and 3.25 microns, can be seen in this graph.

[0015] Figure 3 is a flowchart showing method steps according to exemplary aspects that determine boehmite concentration, alumina concentration of a coated barrier film (including a barrier film having an aluminum compound coating on at least one surface) and optionally determine weight and density of the aluminum compound coating and thickness of the aluminum compound coating. DETAILED DESCRIPTION

[0016] The disclosed aspects are described with reference to the drawings, where like reference numerals are used to refer to like or equivalent elements throughout. The drawings are not to scale and are provided merely to illustrate certain disclosed aspects. Several disclosed aspects are described below with reference made to exemplary applications for purposes of illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the disclosed aspects.

[0017] The battery customer is most concerned with knowing the thickness of the coating on the separator film accurately. Using the disclosed aspects, the thickness of the coating can generally be calculated after first determining the density of the coating, as it has been recognized that the coating thickness measurement / calculation is generally not accurate unless the coating composition is known accurately, as the coating composition determines the coating density, where for LiB, the coating composition can range from pure aluminum oxide to pure boehmite. As noted above, boehmite is used as a precursor material in the production of aluminum oxide, which is a commonly used coating material for separator films. Customer data has shown that some batches of aluminum oxide coating are contaminated with boehmite, but not all batches. The inventors have identified a boehmite-specific spectral component that includes a first and at least a second peak / trough, such as shown by absorption peaks 202a and 202b in the IR spectrum (IR spectrum) described below. Figure 2 (IR spectrum) described below. It is noted that the IR filter is generally centered on a peak, not a trough, but there is no hard and fast rule, as this can depend on many other factors.

[0018] The coated separator film can be examined in either reflectance mode or transmission mode. However, because in transmission mode, the thickness of the separator film (e.g., including the PP) can also be measured, transmission mode can be advantageous compared to reflectance mode. Raman spectroscopy represents an alternative to IR spectroscopy, where Raman spectroscopy can generally be used, but it is generally not suitable for real-time measurements on high-speed production coating machines. The boehmite peaks not only indicate the presence of boehmite in the aluminum oxide coating, but also indicate the concentration based on the amplitude of the boehmite peaks.

[0019] Figure 1 An example disclosed measurement device 100 is depicted that is configured for calculating coating parameters of a coated separator film, including a separator film having an aluminum compound coating on at least one surface, including calculating the concentration of an additive or contaminant, such as boehmite, PVDF, or a combination of boehmite and PVDF, the concentration of aluminum oxide, and optionally the density and weight of the ceramic coating and the thickness of the ceramic coating. The thickness of the ceramic coating can be the most important parameter for a LiB manufacturer, who can be a customer of the device 100.

[0020] Reference is made to Figure 1The coated separator film 180 shown includes a coating material 180b in the form of a sheet of generally polymeric material on at least one surface of the separator / sheet material 180a, the coating material including alumina or other contaminant, or additive, or a mixture of these materials. The contaminant or additive can include boehmite, PVDF, or a binder or a combination of boehmite, PVDF, and binder. The sheet material 180a can include a polymer or a layer of polymer (e.g., polyethylene (PE) or PP). The coating material 180b is generally a layer that is not only composed of alumina or other contaminant / additive, but can also generally include a binder material as described above.

[0021] In Figure 1 , the scanner head 160 includes a top scanner head 160a and a bottom scanner head 160b, which collectively have two sensors therein, including the x-ray sensor 110 and the IR sensor 120. As shown, emitters shown as Tx 110a and Tx 120a are in the top scanner head 160a, and receivers shown as Rx 110b and Rx 120b are in the bottom scanner head 160b. Inside the scan head 160a, scan head 160b, the respective x-ray sensor 110 and IR sensor 120 are mounted along a line that can be oriented parallel to the machine direction (MD) or along the cross direction (CD). The MD orientation helps to ensure that both the x-ray sensor 110 and the IR sensor 120 measure the same portion (area) of the coated separator film 180.

[0022] Still referring to Figure 1 , the scanner head 160a, scanner head 160b can scan the coated separator film 180 that is moving between the scan head 160a and the scan head 160b. The scanner head 160 can scan over a portion of the width or the entire width of the coated separator film 180. After the coating material 180b has been applied to the separator / sheet material 180a, the scanner head 160 is used to scan the respective x-ray sensor 110 and IR sensor 120 over the coated separator film 180.

[0023] In Figure 1 , the x-ray sensor 110 includes an x-ray source shown as Tx 110a, which generally includes an x-ray tube having a high voltage power supply shown as HV PS 112 coupled to the x-ray source for emitting an x-spectrum including x-rays at a plurality of energies. In addition, an x-ray detector shown as Rx 110b is also shown, which is used to provide a measured x-ray signal value in response to receiving x-rays transmitted through the coated separator film 180 after. The x-ray spectrum is generally calculated from a physical model of the particular x-ray tube under particular high voltage conditions.

[0024] InFigure 1 In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b.

[0025] In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b. Figure 1 In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b.

[0026] In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b. Figure 1 In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b.

[0027] In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b. Figure 1 In particular, the x-ray sensor 110 configured at high voltage (e.g., 4 kV to 10 kV) provides a measured x-ray signal value that is about 5 to 10 times more sensitive to the weight of the coating material 180b due to the higher atomic number than the weight of the separator film / material 180a, which in the case of LiB typically includes a plastic film. The IR sensor 120 can provide a weight measurement that is most sensitive to the weight of the separator film / material 180a (e.g., including PE) and thus typically not sensitive to the weight of the coating material 180b.

[0028] Figure 1 ​In the case of coated separator 180, one or more x-ray signals will be transmitted from the emitter 110a / 120a through the coated separator 180. An infrared (IR) signal is obtained from the coated separator 180. Further, the IR signal includes two or more spectral components including a first peak from the separator 180. The processor 151 determines whether a second peak is present among the IR peaks. The processor 151 also determines whether at least one contaminant or additive is present in the coating 180b within the coated separator 180. The processor 151 calculates the concentration or area weight of the at least one contaminant or additive and also calculates the weight, density or thickness of the coating 180b. The contaminant or additive can be boehmite, PVDF or a binder or a combination of boehmite and PVDF or a binder.

[0029] Figure 2 Exemplary IR spectra 201 (where no boehmite peak is shown) from 2 pm to 4 pm are shown for a pure alumina coated polymer separator and IR spectra 202 for an alumina coated polymer separator including some boehmite content. Figure 2 The IR spectra 201 and 202 in are obtained from a laboratory Fourier Transform Infrared Spectrometer (FTIR) equipment. Figure 2 In the case of boehmite, a unique IR signature can be seen in the IR spectra 202, which includes an absorption peak shown as 202a at 3.05 pm and an absorption peak shown as 202b at 3.25 pm. Further, the IR spectra 202 also shows a separate peak for PP or PE shown as 206a at 3.45 pm and 206b at 3.52 pm, which is mainly affected by the weight of the PE / PP separator. It is noted that the use of an online sensor is more common for the spectral region of interest only compared to the full IR spectra 201 or 202.

[0030] With respect to Figure 2 To measure the PE weight, a reference measurement in at least one unaffected area can give a baseline value for the relative measurement. For PE / PP, the absorption peak of choice can be 206b as 206a is heavily absorbed into a place where there is no sensitivity. In the case of Figure 2 In the case of coated separator 180, one or more x-ray signals will be transmitted from the emitter 110a / 120a through the coated separator 180. An infrared (IR) signal is obtained from the coated separator 180. Further, the IR signal includes two or more spectral components including a first peak from the separator 180. The processor 151 determines whether a second peak is present among the IR peaks. The processor 151 also determines whether at least one contaminant or additive is present in the coating 180b within the coated separator 180. The processor 151 calculates the concentration or area weight of the at least one contaminant or additive and also calculates the weight, density or thickness of the coating 180b. The contaminant or additive can be boehmite, PVDF or a binder or a combination of boehmite and PVDF or a binder. Figure 2The IR spectral region shown does not have any absorption bands. The x-ray sensor senses primarily aluminum atoms, and the IR sensor senses boehmite, PVDF, or the binder or a combination of boehmite, PVDF, and binder. This information is sufficient to extract the coating thickness and any contaminant / additive content. These IR spectral components can be used together with the x-ray information obtained from the x-ray sensor 110, which is shown as Figure 1 part of the apparatus 100 in

[0031] Referring to Figure 2 , by measuring the respective inputs from the detectors 110b, 120b of the x-ray sensor 110 and the IR sensor 120, three possible outputs determined can be the weight, density, or thickness of the sheet material 180a, and / or the weight, density, or thickness of the coating material, which typically includes primarily aluminum oxide or a contaminant or additive such as boehmite, PVDF, a binder, or a combination of boehmite, PVDF, and binder. Thus, the coating can include aluminum oxide and a contaminant / additive including boehmite, PVDF, and / or other binder. The total weight of the composite sheet 180a can also be calculated as the sum of the separator weight and the coating weight including any contaminant / additive. The measurements can be calibrated by performing a multi-predictor (x-ray and IR signal) partial least squares regression algorithm (or similar statistical method such as principal component analysis (PCA) or neural networks) on a set of composite coated separators with known separator material weight, coating weight, and composition (concentration) parameters.

[0032] Still referring to Figure 2 , the processor (as shown in Figure 1 ) can solve for the weight of the coated separator, the weight of the coating, and the concentration of the contaminant / additive (boehmite, PVDF, binder, or a combination thereof). This process is typically performed by an algorithm run by a computing device, such as the computing device 150 shown in Figure 1 above. In other embodiments, the embedded processor can also determine the concentration or areal weight of the contaminant or additive including boehmite, PVDF, binder, or a combination of the three.

[0033] With regard to Figure 2 , in the disclosed system such as Figure 1In the apparatus 100 shown in the middle, the combination of the X-ray sensor 110 and the IR sensor 120 is used with the disclosed algorithm to extract the accurate coating weight, as well as the concentration and / or area weight of at least one contaminant / additive such as boehmite, PVDF, binder, or a combination of the three. In addition, such a system is also configured to determine the concentration of alumina, as well as at least one of the weight of the ceramic coating, the density of the ceramic coating, and / or the thickness of the ceramic coating. As mentioned above, other outputs can be derived from these outputs. The above-described Figure 2 The IR signals shown as 202a and 202b (at 3.05 pm and 3.25 pm) in the spectrum 202 in

[0034] In Figure 2 The above-described Figure 2 The IR signals 206a and 206b at 3.45 pm and 3.52 pm shown in the middle in

[0035] Referring to Figure 2 In embodiments, three or four IR wavelengths are used. In addition to the specific boehmite and separator wavelengths, reference wavelengths / channels known in the art can also be employed. The reference wavelengths are typically positioned in a portion of the IR spectrum where the absorption of the components of interest (i.e., the separator and boehmite) is low. The reference wavelengths are used in a known ratio metric technique where the ratio of the amplitude (or intensity) of the IR signal at the measurement wavelength to the IR signal at the reference wavelength is used as the primary input to the computing device or processor. In embodiments, one of the measurement wavelengths will be one at the unique absorption peak of PE or PP as the separator or boehmite. The same or different reference wavelengths can be used in these measurement ratios. In embodiments, two wavelengths can be identified that can be used as reference measurements, such as about 2.8 pm and 3.6 pm.

[0036] With respect to Figure 2 The disclosed aspects can be applied to generally coated separator films that typically include at least one polymer. For other separator types, for example reflective separator materials, the IR measurements can be performed in a reflective mode. The disclosed aspects are applicable to generally determining the respective weight of any coating material including boehmite on any separator film material, where the separator 180a can also include multiple different polymer layers, for example PE / PP / PE, PP / PE / PP, PE / PP / PE / PP / PE.

[0037] Figure 3 is a flowchart showing the steps in the disclosed method 300. Further, the method or process 300 shows how to determine whether at least one contaminant / additive is present. As mentioned above, the contaminant / additive can be boehmite, PVDF, a binder, or a combination of boehmite, PVDF, or a binder.

[0038] In Figure 3 , at step 310, an x-ray signal is received from x-rays transmitted through the coated separator film. The apparatus (such as the apparatus shown in Figure 1 ) can include an x-ray emitter, where the x-ray signal is transmitted through the coated separator film.

[0039] Referring to Figure 3 , at step 320, an IR signal is obtained from the coated separator film. Due to the transmitted x-ray signal, the IR signal is obtained that includes two or more spectral components. Further, the IR signal will include a plurality of peaks, including a first peak from the coated separator film.

[0040] In Figure 3 , at step 330, a processor configured within the apparatus shown in Figure 1 determines whether a second peak is present among the IR peaks. Further, the processor determines whether at least one contaminant or additive is present in the ceramic coating present within the coated separator film. The contaminant / additive can include boehmite, PVDF, or a binder. Alternatively, the contaminant / additive can include a combination of boehmite, PVDF, and a binder.

[0041] With respect to Figure 3 , at step 340, the processor calculates a concentration or area weight of the at least one contaminant or additive, including boehmite, PVDF, or a binder, or a combination of boehmite, PVDF, and a binder. Further, the processor calculates a weight, density, or thickness of the ceramic coating.

[0042] In general, two or more peaks can be identified from the obtained IR signal. The processor can determine whether at least one contaminant or additive is present in the ceramic coating present within the coated separator film from a second peak between the IR peaks. The processor can determine whether the contaminant / additive is boehmite, PVDF, a binder material, or alternatively, a combination of boehmite, PVDF, and a binder. The processor can thereby calculate a concentration or area weight of boehmite, PVDF, or a binder. Further, the processor can calculate a weight, density, or thickness of the ceramic coating.

[0043] While various disclosed aspects have been described above, it should be understood that they have been presented by way of example only, and not in limitation. Numerous changes to the disclosed subject matter can be made in accordance with this disclosure without departing from the spirit or scope of this disclosure. Additionally, while a particular feature can have been disclosed with respect to only one of several implementations, such feature can be combined with one or more other features of the other implementations as can be desired or advantageous for any given or particular application.

Claims

1. A method for detecting a separator membrane, comprising: Receives an X-ray signal that is transmitted from the X-ray emitter through a coated isolation membrane (180). An infrared signal generated from the coated isolation film (180) is obtained, wherein the infrared signal comprises two or more spectral components, the two or more spectral components comprising peaks, the peaks comprising a first peak; The processor (151) determines whether a second peak exists among the peaks, and based on the wavelength of the second peak, the processor (151) determines whether at least one contaminant or additive exists in the coating (180b) present within the coated isolation membrane (180), and wherein the wavelength of the second peak determines the type of at least one contaminant or additive. The type of at least one contaminant or additive is determined based on the wavelength of the second peak; as well as Based on X-ray and infrared signals, the processor (151) calculates the concentration or area weight of the at least one contaminant or additive, as well as the weight, density, or thickness of the coating (180b).

2. The method according to claim 1, wherein the at least one contaminant or additive is boehmite.

3. The method according to claim 1, wherein the at least one contaminant or additive is an adhesive material.

4. The method according to claim 1, further comprising: The processor (151) determines whether boehmite is present in the coated isolation membrane (180).

5. The method according to claim 1, further comprising: Determine whether polyvinylidene fluoride (PVDF) is present in the coating (180b).

6. The method according to claim 1, further comprising: The concentration of the ceramic coating is determined based on the X-ray signal.

7. The method according to claim 1, further comprising: Determine the weight and density of the ceramic coating within the coated isolation membrane.

8. The method according to claim 3, wherein the adhesive material is polyvinylidene fluoride (PVDF).

9. The method of claim 7, wherein the ceramic coating is alumina or silicon oxide.

10. The method of claim 1, wherein the first peak is at a wavelength of 3.05 μm and the second peak is at a wavelength of 3.25 μm.

11. A method for detecting a separator membrane, comprising: Receive one or more X-ray signals, the one or more X-ray signals being transmitted through a coated isolation membrane (180) including a ceramic coating. An infrared signal generated from the coated isolation membrane (180) is obtained by the processor (151), the infrared signal having a first peak for the coated isolation membrane (180) and a second peak for the contaminant or additive; The processor (151) determines the presence of the second peak based on the infrared signal, wherein the processor (151) determines the type of contaminant or additive present in the ceramic coating within the coated isolation membrane (180) based on the wavelength of the second peak, and wherein the wavelength of the second peak determines the type of at least one contaminant or additive. The type of at least one contaminant or additive is determined based on the wavelength of the second peak; as well as The processor (151) calculates the concentration of the contaminant or additive based on the second peak and calculates the concentration of the ceramic coating based on the one or more X-ray signals.

12. The method according to claim 11, further comprising: The processor (151) determines the weight, density, or thickness of the ceramic coating.

13. The method of claim 11, wherein the processor (151) determines that the contaminant or additive is an adhesive material.

14. The method of claim 11, wherein the first peak is at a wavelength of 3.05 μm and the second peak is at a wavelength of 3.25 μm.

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