A combined device for material surface and bulk testing

Abstract

The application discloses a combined device for material surface and bulk phase testing, and belongs to the technical field of material analysis and testing. In order to study and analyze the micro-particle activity of the surface and bulk phase structure of a lithium ion battery multi-layer structure, the combined device comprises a hard X-ray photoelectron spectrometer (1) and an X-ray Raman scattering spectrometer (2). When incident hard X-rays (31) are obliquely incident on a sample (41) located at a sample point (4), electrons can be excited and photons can be scattered. The hard X-ray photoelectron spectrometer (1) can detect the electrons, and the X-ray Raman scattering spectrometer (2) can detect the photons. The combined device is based on a synchrotron radiation light source facility, and combines the hard X-ray photoelectron spectroscopy and the hard X-ray Raman scattering technology to be applied to lithium ion battery testing. The specific structure is simple, and the lithium ion battery can be subjected to synchronous analysis of the surface layer and the bulk phase structure.

Description

Technical Field

[0001] This invention relates to the field of materials analysis and testing technology, specifically a combined device for testing the surface and bulk phase of materials. Background Technology

[0002] With the increasing depletion of traditional fossil fuels, issues such as energy crisis, environmental pollution, and ecological pollution have gradually gained attention. Lithium-ion batteries, as a green energy source, possess advantages such as high voltage, high specific energy, high output power, and a wide range of applications, and are considered one of the most promising electrochemical energy storage materials of our time. However, existing batteries still fall short of the requirements for longer cycles and higher specific energy. Further research and development of materials with high specific energy and high voltage are needed, along with a deeper understanding and exploration of battery structural evolution, charge transfer, and failure mechanisms, to guide the development of battery systems with longer lifespans and greater safety.

[0003] During the cycling process of lithium-ion batteries, the electrode material and electrolyte react at the solid-liquid interface to form a passivation film (SEI film) covering the surface of the material. This film mainly forms during the first charge and discharge cycle and continues to form in subsequent cycles. The SEI film on the positive electrode surface originates from the oxidation products of the positive electrode material and electrolyte, while the SEI film on the negative electrode surface originates from the reduction products of the negative electrode material and electrolyte. Studies have shown that the formation of the SEI film consumes a large number of Li ions, but it also plays a role in protecting the electrode. Therefore, this important structure in lithium-ion batteries can be studied using photoelectron spectroscopy (XPS).

[0004] XPS technology can theoretically reveal the chemical and electronic structure of the surface and interfaces of material layers, and can study charge distribution, oxidation state, ionicity, etc., through chemical shift. Laboratory-grade XPS instruments typically use X-ray sources with energies of 1486.7 eV (Al Kα) and 1253.6 eV (Mg Kα), which can produce high intensity and inherently narrow linewidths, providing good energy resolution. However, soft X-ray XPS instruments can only acquire surface information of samples at a depth of about 10 nm. Therefore, the emergence of high-photon-flux hard X-ray photoelectron spectroscopy (HAXPES) can meet the experimental needs of greater detection depths. Using excitation energies between 6 keV and 12 keV, it can detect depths of approximately 50 nm to 200 nm. Therefore, this technology can be used to study the structure and electronic information of deeper SEI core electrons.

[0005] Although HAXPES technology has made significant breakthroughs in detection depth compared to conventional XPS, its reliance on the principle of photoelectron ingress / electron egress means that the kinetic energy of escaping photoelectrons limits the detection depth. Therefore, it remains suitable only for probing the electronic structure of subsurface regions and is not applicable to the analysis of the bulk structure of lithium-ion batteries. In lithium-ion electronic devices, key buried interfaces, bottom electrode materials, and their lithiation mechanisms still cannot be analyzed and characterized. Summary of the Invention

[0006] To study and analyze the microscopic particle activity of the surface and bulk structures of lithium-ion batteries, this invention provides a combined device for testing the surface and bulk structures of materials. This device is based on a synchrotron radiation source facility and combines hard X-ray photoelectron spectroscopy with hard X-ray Raman scattering technology for testing lithium-ion batteries. It has the advantage of simple structure and can perform simultaneous analysis of the surface and bulk structures of lithium-ion batteries.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] A combined apparatus for testing the surface and bulk phase of materials includes a hard X-ray photoelectron spectrometer and an X-ray Raman scattering spectrometer. When incident hard X-rays graze incident on a sample located at a sample point, electrons are excited and photons are scattered. The hard X-ray photoelectron spectrometer can detect the electrons, and the X-ray Raman scattering spectrometer can detect the photons.

[0009] The beneficial effects of this invention are: the method of combining hard X-ray photoelectron spectroscopy and hard X-ray Raman scattering simplifies the testing steps for lithium-ion batteries from surface to bulk phase. At the same time, photon and electron spectra can be collected simultaneously at the same focusing point of the sample, enabling the characterization of information such as the internal structural evolution and charge transfer of lithium-ion batteries. In addition, since the XRS spectrometer is in a vacuum chamber, it can collect XRS data with weak signals to the greatest extent. Attached Figure Description

[0010] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0011] Figure 1 This is a schematic diagram of the combined device for testing the surface and bulk phase of materials as described in this invention.

[0012] Figure 2 This is a schematic diagram of the product structure of the combined device for testing the surface and bulk phase of materials described in this invention.

[0013] Figure 3 It is along Figure 2A schematic diagram of the direction A in the middle.

[0014] Figure 4 This is a schematic diagram of the working state of the combined device for testing the surface and bulk phase of materials described in this invention.

[0015] The annotations in the attached figures are explained as follows:

[0016] 1. Hard X-ray photoelectron spectrometer; 2. X-ray Raman scattering spectrometer; 3. Hard X-ray emitter; 4. Sample spot; 5. Sample analysis chamber; 6. Sample mounting rack; 7. Sample preparation chamber; 8. Rowland circle; 9. Pre-sample preparation chamber;

[0017] 21. Spectrometer housing; 22. Spherical curved crystal; 23. Detector; 24. Slide rail;

[0018] 31. Incident hard X-rays;

[0019] 41. Sample;

[0020] 51. Electron beam interface; 52. Photon beam interface; 53. X-ray interface;

[0021] 71. First sealed partition door. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] A combined apparatus for testing the surface and bulk phase of materials includes a hard X-ray photoelectron spectrometer 1 and an X-ray Raman scattering spectrometer 2. When incident hard X-rays 31 graze-incidentally strike a sample 41 (such as a lithium-ion battery sample to be tested) located at sample point 4, electrons are excited and photons are scattered. The electrons can enter the hard X-ray photoelectron spectrometer 1, and the photons can enter the X-ray Raman scattering spectrometer 2. The hard X-ray photoelectron spectrometer 1 can detect the electrons, and the X-ray Raman scattering spectrometer 2 can detect the photons. Figure 1 As shown.

[0024] In this embodiment, the axis L1 of the entrance to the hard X-ray photoelectron spectrometer 1, the axis L2 of the entrance to the X-ray Raman scattering spectrometer 2, and the incident hard X-ray 31 are all located in the same plane, which can be called the test plane. The test plane is parallel to... Figure 1The paper. The axis L1 of the entrance of the hard X-ray photoelectron spectrometer 1, the axis L2 of the entrance of the X-ray Raman scattering spectrometer 2, and the incident hard X-ray 31 intersect at sample point 4. The hard X-ray photoelectron spectrometer 1 is used to obtain the relationship between electron intensity and electron kinetic energy, i.e., the energy spectrum. The X-ray Raman scattering spectrometer 2 is used to receive and count photons, thereby obtaining the photon energy spectrum.

[0025] In this embodiment, the angle between the incident hard X-ray 31 and the axis L1 of the entrance of the hard X-ray photoelectron spectrometer 1 is 90°, and the angle between the incident hard X-ray 31 and the axis L2 of the entrance of the X-ray Raman scattering spectrometer 2 is an obtuse angle.

[0026] In this embodiment, the combined apparatus for material surface and bulk phase testing further includes a sample analysis chamber 5 and a hard X-ray emitter 3. The hard X-ray emitter 3 emits incident hard X-rays 31. The sample analysis chamber 5 contains a closed sample analysis cavity, and a sample mounting rack 6 is provided inside the sample analysis cavity. The sample 41 can be mounted on the sample mounting rack 6, and the sample point 4 is located inside the sample analysis cavity. The sample analysis chamber 5 is mainly used to control the sample environment, prevent sample contamination, and ensure the stability of experimental conditions, such as... Figure 2 As shown.

[0027] In this embodiment, the sample analysis chamber 5 is equipped with an electron beam interface 51, a photon beam interface 52, and an X-ray interface 53. The inlet of the hard X-ray photoelectron spectrometer 1 is sealed to the electron beam interface 51, the inlet of the X-ray Raman scattering spectrometer 2 is sealed to the photon beam interface 52, and the outlet of the hard X-ray emitter 3 is sealed to the X-ray interface 53. The axis of the outlet of the hard X-ray emitter 3 coincides with the incident hard X-ray 31.

[0028] In this embodiment, a sample preparation chamber 7 is connected to the sample analysis chamber 5. The sample preparation chamber 7 contains a sealed sample preparation cavity. A first sealed partition door 71 is provided between the sample analysis chamber 5 and the sample preparation chamber 7. A second sealed partition door is provided on the sample preparation chamber 7. The sample mounting frame 6 is a six-axis robotic arm capable of clamping and fixing the sample 41. The six-axis robotic arm can be used for operations such as alignment, tilting and rotation adjustment of the sample 41, depth analysis of the sample, and sample exchange. Figure 2 and Figure 3 As shown.

[0029] The sample mounting frame 6 can be an existing six-axis robot. The sample mounting frame 6 can transport the sample 41 in the sample preparation chamber to the sample point 4 in the sample analysis chamber, and can also transport the sample 41 located at the sample point 4 in the sample analysis chamber to the sample preparation chamber. The sample mounting frame 6 provides six degrees of freedom to the sample 41 at the sample point 4.

[0030] In this embodiment, the sample analysis chamber 5 can be approximately a cylindrical structure closed at both ends, and the axis of the sample analysis chamber 5 is perpendicular to the test plane. Both the sample analysis chamber 5 and the sample preparation chamber 7 are connected to a vacuum device, which can create a vacuum in both chambers. The sample preparation chamber 7 is equipped with a sample cleaning device and a sample cleaning table. The cleaning device can be an air spray gun or a liquid spray gun. The sample preparation chamber 7 is used for surface cleaning of the sample and for sample transfer.

[0031] Additionally, a pre-sample preparation chamber 9 can be connected to the sample preparation chamber 7. The pre-sample preparation chamber 9 contains a pre-sample preparation cavity. The second sealed partition door is located between the sample preparation chamber 7 and the pre-sample preparation chamber 9. The pre-sample preparation chamber 9 is equipped with a third sealed partition door. The pre-sample preparation chamber 9 is also connected to a vacuum device capable of evacuating the pre-sample preparation cavity. The pre-sample preparation chamber 9 is used for sample introduction and removal, and for pre-treating the system's vacuum level.

[0032] In this embodiment, the X-ray Raman scattering spectrometer 2 includes a spectrometer housing 21, a spherically curved crystal 22, and a detector 23. The spherically curved crystal 22 is located inside the spectrometer housing 21. The spherically curved crystal 22 is a prior art product and can also be referred to as a spherically curved analytical crystal array or a spherically curved crystal analyzer. The spherically curved crystal 22 is a small array composed of Si analytical crystals and is used to receive and reflect X-rays at different scattering angles. The detector 23 is located inside the sample analysis chamber. The detector 23 is a two-dimensional X-ray detector, and can be a PILATUS 500k detector manufactured by DECTRIS AG, Switzerland. The receiving surface of the detector 23 faces the spherically curved crystal 22. After the photons reach the spherically curved crystal 22, the spherically curved crystal 22 reflects the photons to the detector 23, which then receives the photons.

[0033] In this embodiment, the spectrometer housing 21 has a cylindrical structure that is closed at one end and open at the other. The open end of the spectrometer housing 21 is sealed to the photon beam interface 52. The axis of the spectrometer housing 21 coincides with the axis L2 of the entrance of the X-ray Raman scattering spectrometer 2. A slide rail 24 is provided inside the spectrometer housing 21. The spherical curved crystal 22 is mounted on the slide rail 24 through a sliding seat. The spherical curved crystal 22 can move along the axial direction of the entrance of the X-ray Raman scattering spectrometer 2. Figure 1 and Figure 2 As shown.

[0034] In this embodiment, the spherical curved crystal 22 has a spherical segment structure, with a concave surface on one side and a convex surface on the other. The concave surface of the spherical segment faces (towards) the sample point 4, and the convex surface faces away from the sample point 4. The diameter of the spherical segment can be 100 mm, and the radius of the sphere containing the spherical segment can be 500 mm. The axis L3 of the spherical curved crystal 22 is located within the test plane. The axis L3 of the spherical curved crystal 22 is located between the axis L2 of the entrance of the X-ray Raman scattering spectrometer 2 and the detector 23. Both the axis L2 of the entrance of the X-ray Raman scattering spectrometer 2 and the axis L3 of the spherical curved crystal 22 pass through the center point of the spherical curved crystal 22. The angle between the axis L2 of the entrance of the X-ray Raman scattering spectrometer 2 and the axis L3 of the spherical curved crystal 22 is approximately 1°.

[0035] In this embodiment, the center point of sample point 4, the center point of the spherically curved crystal 22, and the center point of the receiving surface of detector 23 are located on a virtual Rowland circle 8. The radius of Rowland circle 8 is twice the radius of the sphere containing the spherical segment. For example, if the radius of the sphere containing the spherical segment is 500 mm, then the radius of Rowland circle 8 is 1000 mm. The center of Rowland circle 8 can be located on the axis L2 of the entrance of X-ray Raman scattering spectrometer 2, and Rowland circle 8 can be located within the test plane, such as... Figure 1 As shown.

[0036] Sample point 4 is a virtual point. The distance from the center point of the spherical curved crystal 22 to its edge is the same. If the receiving surface of detector 23 is rectangular, the distance from the center point of the receiving surface of detector 23 to its four corners is the same. The line connecting the center point of the receiving surface of detector 23 and the center point of the spherical curved crystal 22 is perpendicular to the receiving surface of detector 23. All components of the combined material surface and bulk phase testing device described in this invention can be products from existing technologies.

[0037] The working process of the combined device for testing the surface and bulk phase of materials (also known as the material surface and bulk phase testing device) is described below.

[0038] After cleaning, sample 41 is placed in the sample analysis chamber. Hard X-ray emitter 3 emits incident hard X-rays 31 into the sample analysis chamber. The incident hard X-rays 31 graze the sample 41 at the incident sample point 4, exciting electrons and scattering photons. Hard X-ray photoelectron spectrometer 1 collects electrons at a 90° angle parallel to the photon polarization vector relative to the incident hard X-rays 31. The scattered photons are emitted in a grazing-out manner. The scattered photons first travel to the spherical curved crystal 22 (fixed energy 10 keV). The spherical curved crystal 22 forms a fixed Bragg angle of approximately 90° with the scattered light. The spherical curved crystal 22 reflects the photons, and the reflected photons fly to the receiving surface of detector 23. The receiving surface of detector 23 collects photon data, such as... Figure 4 As shown.

[0039] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical solutions, and embodiments of the present invention can be freely combined and used together.

Claims

1. A combined apparatus for testing the surface and bulk phase of materials, characterized in that, The combined apparatus for testing the surface and bulk of the material includes a hard X-ray photoelectron spectrometer (1) and an X-ray Raman scattering spectrometer (2). When the incident hard X-ray (31) grazes into the sample (41) located at the sample point (4), it can excite electrons and scatter photons. The hard X-ray photoelectron spectrometer (1) can detect the electrons, and the X-ray Raman scattering spectrometer (2) can detect the photons. The axis of the entrance of the hard X-ray photoelectron spectrometer (1), the axis of the entrance of the X-ray Raman scattering spectrometer (2), and the incident hard X-ray (31) are all located in the same plane, which is the test plane. The axis of the entrance of the hard X-ray photoelectron spectrometer (1), the axis of the entrance of the X-ray Raman scattering spectrometer (2), and the incident hard X-ray (31) intersect at the sample point (4).

2. The combined apparatus for testing material surface and bulk phase according to claim 1, characterized in that, The angle between the incident hard X-ray (31) and the axis of the entrance of the hard X-ray photoelectron spectrometer (1) is 90°, and the angle between the incident hard X-ray (31) and the axis of the entrance of the X-ray Raman scattering spectrometer (2) is obtuse.

3. The combined apparatus for testing material surface and bulk phase according to claim 1, characterized in that, The combined apparatus for testing the surface and bulk of the material also includes a sample analysis chamber (5) and a hard X-ray emitter (3). The sample analysis chamber (5) is provided with a sample analysis cavity, and a sample mounting rack (6) is provided in the sample analysis cavity. The sample (41) can be mounted on the sample mounting rack (6), and the sample point (4) is located in the sample analysis cavity.

4. The combined apparatus for testing material surface and bulk phase according to claim 3, characterized in that, The sample analysis chamber (5) is equipped with an electron beam interface (51), a photon beam interface (52) and an X-ray interface (53). The inlet of the hard X-ray photoelectron spectrometer (1) is connected to the electron beam interface (51), the inlet of the X-ray Raman scattering spectrometer (2) is connected to the photon beam interface (52), and the outlet of the hard X-ray emitter (3) is connected to the X-ray interface (53).

5. The combined apparatus for testing material surface and bulk phase according to claim 3, characterized in that, The sample analysis chamber (5) is connected to the sample preparation chamber (7). The sample preparation chamber (7) is provided with a sample preparation cavity. A first sealed partition door (71) is provided between the sample analysis chamber (5) and the sample preparation chamber (7). A second sealed partition door is provided on the sample preparation chamber (7). The sample mounting rack (6) is a six-axis robot. The sample mounting rack (6) can transport the sample (41) in the sample preparation cavity to the sample point (4) in the sample analysis chamber.

6. The combined apparatus for testing material surface and bulk phase according to claim 5, characterized in that, Both the sample analysis chamber (5) and the sample preparation chamber (7) are connected to a vacuum device. The sample analysis chamber (5) is equipped with a sample inlet and outlet, and the sample preparation chamber (7) is equipped with a sample cleaning device.

7. The combined apparatus for testing material surface and bulk phase according to claim 3, characterized in that, The X-ray Raman scattering spectrometer (2) contains a spectrometer housing (21), a spherical curved crystal (22), and a detector (23). The spherical curved crystal (22) is located inside the spectrometer housing (21), and the detector (23) is located inside the sample analysis chamber. The receiving surface of the detector (23) faces the spherical curved crystal (22). After the photon reaches the spherical curved crystal (22), the spherical curved crystal (22) can reflect the photon to the detector (23), and the detector (23) can receive the photon.

8. The combined apparatus for testing material surface and bulk phase according to claim 7, characterized in that, The spherical curved crystal (22) is a spherical segment with the concave surface facing the sample point (4). The axis of the spherical curved crystal (22) is located in the test plane and is located between the axis of the entrance of the X-ray Raman scattering spectrometer (2) and the detector (23).

9. The combined apparatus for testing material surface and bulk phase according to claim 8, characterized in that, The spherical curved crystal (22) can move along the axis of the entrance of the X-ray Raman scattering spectrometer (2). The sample point (4), the center point of the spherical curved crystal (22) and the center point of the receiving surface of the detector (23) are located on a Rowland circle (8), the radius of which is twice the radius of the sphere on which the spherical facet is located.

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