Battery in-situ X-ray diffraction test assembly and device

Abstract

The utility model relates to a battery in-situ X-ray diffraction test assembly and device. The battery in-situ X-ray diffraction test assembly comprises: a base provided with a first accommodating space; the first electrode is arranged at the bottom of the first accommodating space; a first groove is formed in the upper surface of the cover body, a second containing space communicated with the first groove is formed in the lower surface of the cover body, the cover body and the base are oppositely arranged and detachably connected, and the second containing space is communicated with the first containing space; a second groove is formed in the upper surface of the second electrode, a third containing space communicated with the second groove is formed in the lower surface of the second electrode, the second electrode is arranged in the second containing space, the second electrode and the first electrode are arranged in a spaced mode, and the second groove is communicated with the first groove; and the third accommodating space is communicated with the first accommodating space, and defines a sample accommodating space with the second electrode and the first electrode. Therefore, the assembly and the device are good in test experiment data stability and high in consistency.

Description

Technical Field

[0001] The present application relates to the field of X-ray diffraction testing devices. Specifically, the present application relates to an in-situ X-ray diffraction testing component and device for batteries. Background Art

[0002] Lithium-ion batteries have been widely used in portable electronic devices and electric vehicles and are currently the most widely used energy storage devices. Excellent lithium-ion batteries need to have higher energy density, power density, as well as longer service life and cycle life. Developing advanced lithium-ion batteries not only requires optimizing existing electrode materials but also developing new materials with higher electrochemical performance. When developing and designing lithium-ion batteries from a materials perspective, it is necessary to deeply understand the relationship between the structural changes of materials during the electrochemical process and battery performance. In recent years, more and more advanced characterization techniques have emerged. Although ex-situ characterization techniques can provide valuable information, for battery materials, obtaining information under real battery operating conditions (in-situ characterization) is crucial for evaluating material performance. The electrochemical performance of electrode materials is not only related to the original structure but also to the structural stability and structural changes during the electrochemical process.

[0003] Therefore, the current in-situ X-ray diffraction testing components and devices for batteries. Summary of the Utility Model

[0004] In the prior art, a variety of in-situ electrochemical testing devices for X-ray diffraction (XRD) are disclosed. In-situ analysis mainly uses two types of X-rays, high-energy X-rays or low-energy X-rays. When using high-energy X-rays, the transmission mode is generally utilized to analyze button cells or soft-pack batteries encapsulated with Kapton film. However, although Kapton film is easy to manufacture and chemically inert, the flexibility of Kapton film can lead to uneven pressure on the electrodes. During the charge and discharge of the battery, the electrodes near the Kapton film window may have poor contact, and air and moisture may enter the battery interior through the Kapton film window, ultimately affecting the electrochemical performance of the battery under test. When using low-energy X-rays, the XRD in-situ electrochemical testing device is mainly a Swagelok Cell for analysis in the reflection mode. However, the Swagelok Cell has high requirements for assembly operations, and the Swagelok Cell is prone to phenomena such as liquid leakage and air leakage that affect the characterization consistency, resulting in a high experimental failure rate. In addition, the Swagelok Cell needs to use beryllium (Be) metal sheets to encapsulate the electrode sheets to be analyzed, and Be metal is highly toxic, posing a certain safety risk to experimental personnel. To alleviate or solve at least one of the above-mentioned problems, the present application provides a battery in-situ X-ray diffraction testing component and device. This component and device are independent of other device hardware and can achieve fast and convenient on-machine analysis without shutting down the device or replacing the sample stage, with good stability and high consistency of test experimental data.

[0005] On the one hand, the present application provides a battery in-situ X-ray diffraction testing component, which includes: a base provided with a first accommodation space; a first electrode disposed at the bottom of the first accommodation space; a cover body having a first groove on its upper surface and a second accommodation space communicating with the first groove on its lower surface. The cover body is disposed opposite to the base and is detachably connected, and the second accommodation space communicates with the first accommodation space; a second electrode having a second groove on its upper surface and a third accommodation space communicating with the second groove on its lower surface. The second electrode is disposed in the second accommodation space and is spaced apart from the first electrode, and the second groove communicates with the first groove; wherein, the third accommodation space communicates with the first accommodation space and defines a sample accommodation space together with the second electrode and the first electrode.

[0006] On the other hand, the present application provides an X-ray diffraction testing device, which includes: an X-ray source and the aforementioned battery in-situ X-ray diffraction testing component, and the upper surface of the sample accommodation space is at the same working height as the X-ray source.

[0007] The beneficial effects of the present application are as follows:

[0008] The in-situ X-ray diffraction test component and device of the present application have at least one of the following advantages: The component and device can avoid Kapton film or Be encapsulation for the battery to be tested. By using a battery sample with a window design to replace Kapton film or Be encapsulation, the test and analysis of the reflection mode of materials at low energy are realized; compared with the test of Swagelok-type batteries, the in-situ XRD test of this component and device has better test data consistency and repeatability, does not use highly toxic Be, has low sample production cost, short cycle, and high test success rate; the component and device are independent of other device hardware, and can achieve fast and convenient on-machine analysis without shutting down the device or replacing the sample stage, and the test experimental data has good stability and high consistency. Description of the Drawings

[0009] Figure 1 It is a schematic structural diagram of an in-situ X-ray diffraction test component of a battery according to an embodiment of the present application.

[0010] Figure 2 It is an exploded view of an in-situ X-ray diffraction test component of a battery according to an embodiment of the present application.

[0011] Figure 3 It is a partial schematic structural diagram of an in-situ X-ray diffraction test component of a battery according to an embodiment of the present application.

[0012] Figure 4 It is a front view of an in-situ X-ray diffraction test component of a battery according to an embodiment of the present application.

[0013] Figure 5 It is Figure 4 A cross-sectional view along A-A.

[0014] Figure 6 It is a side view of an in-situ X-ray diffraction test component of a battery according to an embodiment of the present application.

[0015] Figure 7 It is Figure 6 A cross-sectional view along B-B.

[0016] Figure 8 It is a schematic structural diagram of a battery sample according to an embodiment of the present application.

[0017] Figure 9 It is a test spectrum of an in-situ X-ray diffraction test device of a battery according to an embodiment of the present application.

[0018] Description of the Reference Numerals:

[0019] 1: Cover body; 2: Base; 3: Second electrode; 4: First electrode; 5: Second through-hole; 6: First through-hole; 7: Screw hole; 8: Screw; 11: First groove; 12: Second accommodation space; 111: First slot; 112: Second slot; 113: Third slot; 21: First accommodation space; 22: Annular groove; 211: Second cavity; 31: Second groove; 32: Third accommodation space; 9: Battery sample; 91: Positive electrode case; 92: Electrode to be measured; 93: Separator; 94: Lithium sheet; 95: Spacer; 96: Spring piece; 97: Negative electrode case; 98: Opening. Detailed implementation manners

[0020] For the sake of simplicity, this application only specifically discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, each individually disclosed point or single numerical value itself can be used as a lower limit or an upper limit and combined with any other point or single numerical value or combined with other lower limits or upper limits to form a range not explicitly recited.

[0021] Unless otherwise specified, the terms used in this application have the well-known meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values of the various parameters mentioned in this application can be measured by various commonly used measurement methods in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0022] The list of items connected by the terms "at least one of", "at least one of", "at least one kind of" or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may include a single component or multiple components. Item B may include a single component or multiple components. Item C may include a single component or multiple components.

[0023] In the context of the present application, terms such as "center", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present application.

[0024] In the context of the present application, terms such as "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features.

[0025] In the context of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath", and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0026] The present application will be further described below in conjunction with specific embodiments. It should be understood that these specific embodiments are only used to illustrate the present application and not to limit the scope of the present application.

[0027] I. Battery in-situ X-ray diffraction test assembly

[0028] The present application provides a battery in-situ X-ray diffraction test assembly, referring to Figures 1 to 7, the in-situ X-ray diffraction test assembly for the battery includes: a base 2, a first electrode 4, a cover 1, and a second electrode 3. The base 2 is provided with a first accommodation space 21; the first electrode 4 is disposed at the bottom of the first accommodation space 21; the upper surface of the cover 1 has a first groove 11, and the lower surface of the cover 1 has a second accommodation space 12 communicating with the first groove 11. The cover 1 is disposed opposite to the base 2 and is detachably connected, and the second accommodation space 12 communicates with the first accommodation space 21; the upper surface of the second electrode 3 has a second groove 31, and the lower surface of the second electrode 3 has a third accommodation space 32 communicating with the second groove 31. The second electrode 3 is disposed in the second accommodation space 12 and is spaced apart from the first electrode 4, and the second groove 31 communicates with the first groove 11; wherein, the third accommodation space 32 communicates with the first accommodation space 21 and defines a sample accommodation space (not shown in the figure) with the second electrode 3 and the first electrode 4.

[0029] Thus, the in-situ X-ray diffraction test assembly and device for the battery have at least one of the following advantages: the assembly and device can avoid using Kapton film or Be encapsulation for the battery to be tested. By using a battery sample with a window design to replace Kapton film or Be encapsulation, the test analysis of the reflection mode of materials at low energy is realized; the in-situ XRD test of the assembly and device has better test data consistency and repeatability compared with the test of Swagelok-type batteries, and does not use highly toxic Be. The sample production cost is low, the cycle is short, and the test success rate is high; the assembly and device are independent of other equipment hardware, and can realize fast and convenient on-machine analysis without shutting down the equipment and replacing the sample stage. The test experimental data has good stability and high consistency.

[0030] In some embodiments, screw holes 7 are provided on the base 2 and the cover 1, and screws 8 are disposed in the screw holes 7 to fix the base 2 and the cover 1. Thus, through the cooperation of the screws 8 and the screw holes 7, the detachable connection between the base 2 and the cover 1 is realized. The screws 8 and the screw holes 7 do not contact the first electrode 4 and the second electrode 3, avoiding short circuit.

[0031] In some embodiments, the first electrode 4 is electrically connected to a first wire (not shown in the figure). The base 2 has a first through-hole 6, and the first wire extends outside the base 2 through the first through-hole 6. In some embodiments, the second electrode 3 is electrically connected to a second wire (not shown in the figure). The cover 1 has a second through-hole 5, and the second wire extends outside the cover 1 through the second through-hole 5. The first wire and the second wire are used for electrically connecting to an external power source. For example, the first wire and the second wire are connected (such as a quick-insert type wire interface) to a charge and discharge instrument to apply a current, so as to perform in-situ testing on the sample to be tested in the sample accommodation space. For example, the first electrode 4 is connected to the negative electrode of the charge and discharge instrument through the first wire, and the second electrode 3 is connected to the positive electrode of the charge and discharge instrument through the second wire. It should be noted that both the cover 1 and the base 2 are made of insulating materials, such as polyether ether ketone (PEEK), and the second electrode 3 and the first electrode 4 are both made of conductive materials, such as copper.

[0032] In some embodiments, the installation positions of the first through-hole 6 and the second through-hole 5 are not particularly limited. The heights of the first through-hole 6 and the second through-hole 5 on the battery in-situ X-ray diffraction test assembly are different. The projections of the first through-hole 6 and the second through-hole 5 on the base 2 may coincide with each other or may not coincide. Those skilled in the art can adjust the installation positions of the first through-hole 6 and the second through-hole 5 according to actual needs.

[0033] In some embodiments, the second electrode 3 is disposed in the second accommodation space 12 and is spaced apart from the first electrode 4. Thus, it is possible to avoid short circuit between the second electrode 3 and the first electrode 4, and the second electrode 3 and the first electrode 4 can be in direct contact with the sample to be tested located in the sample accommodation space.

[0034] In some embodiments, refer to Figures 4 to 7 , the base 2 is a cylinder, and the outer wall of the base 2 has a circumferential annular groove 22, and the first through-hole 6 is disposed on the annular groove 22.

[0035] In some embodiments, along the direction from the base 2 towards the cover 1, the first accommodation space 21 includes a first cavity (not shown in the figure) and a second cavity 211 that are communicated. The transverse width of the first cavity is greater than the transverse width of the second cavity 211, and the first electrode 4 is located in the first cavity.

[0036] In some embodiments, the first electrode 4 is a cylinder, and the orthographic projection of the second electrode 3 on the first electrode 4 is located within the area where the first electrode 4 is located.

[0037] In some embodiments, the orthographic projection of the second electrode 3 on the first electrode 4 is located within the area where the orthographic projection of the second cavity 211 on the first electrode 4 is located.

[0038] In some embodiments, the lateral width of the second cavity 211 is greater than the lateral width of the third accommodation space 32.

[0039] In some embodiments, referring to Figure 3 , the first groove 11 laterally penetrates the upper surface of the cover body 1. Along the lateral penetration direction of the first groove 11, the first groove 11 includes a first slot 111, a second slot 112, and a third slot 113.

[0040] In some embodiments, the second groove 31 laterally penetrates the upper surface of the second electrode 3.

[0041] In some embodiments, the orthographic projections of the first slot 111 and the third slot 113 on the second electrode 3 are located within the second groove 31, and the orthographic projection of the second slot 112 on the second electrode 3 is at least partially located outside the second groove 31.

[0042] In some embodiments, the upper surface of the second electrode 3 is exposed on the upper surface of the cover body 1 through the second slot 112.

[0043] In some embodiments, the orthographic projection of the second slot 112 on the first electrode 4 coincides with the orthographic projection of the third accommodation space 32 on the first electrode 4.

[0044] In some embodiments, the sample accommodation space is used to accommodate a battery sample 9. The upper surface of the battery sample 9 is electrically connected to the second electrode 3, and the lower surface of the battery sample 9 is electrically connected to the first electrode 4. Thus, the battery sample 9 can be connected to a charge and discharge instrument through the second electrode 3 and the first electrode 4 to load current, so as to perform in-situ testing on the battery sample 9 in the sample accommodation space. In some embodiments, for the battery sample 9 located in the sample accommodation space, the center of its orthographic projection on the base 2 coincides with the center of the base 2.

[0045] In some embodiments, the type of the battery sample 9 is a windowed button battery. When the windowed button battery is located in the sample accommodation space of the test assembly, the windowed part faces the cover body 1. In some embodiments, when the battery sample is located in the sample accommodation space, the lower surface of the battery sample 9 is a negative electrode shell 97, the upper surface of the battery sample 9 is a positive electrode shell 91, the positive electrode shell 91 has an opening 98, and the battery sample 9 includes a to-be-tested electrode sheet 92. The to-be-tested electrode sheet 92 is exposed on the upper surface of the cover body 1 through the opening 98, the second groove 31, and the first groove 11 in sequence. Thus, the battery sample 9 is of a windowed type and can directly perform in-situ testing.

[0046] In some embodiments, with reference to Figure 8 , the battery sample 9 includes a positive electrode case 91, a test electrode sheet 92, a separator 93, a lithium sheet 94, a gasket 95, a spring sheet 96, and a negative electrode case 97 that are sequentially stacked. The positive electrode case 91 has an opening 98. When the battery sample 9 is located in the sample accommodation space of the test assembly, the opening 98 faces the cover 1. The structures and material selections of each component in the battery sample 9 are not particularly limited, and those skilled in the art can make selections according to actual needs as long as the X-ray diffraction test function can be realized. Thus, by performing a windowing process on the upper surface of the positive electrode case 91 of the button battery and having the window face upward when the button battery is placed on the sample stage, the test active material in the test electrode sheet 92 and the current collector are directly exposed to X-rays (such as low-energy X-rays) for crystal diffraction testing. In some embodiments, the test electrode sheet 92 includes a current collector and a test active material layer provided on the surface of the current collector. The test active material layer faces the separator 93, that is, away from the opening 98 of the positive electrode case 91. The test active material layer includes a test active material, and the test active material can be a positive electrode active material or a negative electrode active material. The specific type of the positive electrode active material or the negative electrode active material is not particularly limited. For example, the test active material can be a nickel cobalt manganese (NCM) ternary positive electrode active material or a lithium iron phosphate positive electrode active material, and the corresponding current collector is aluminum; alternatively, the test active material can be a graphite negative electrode material or a silicon oxygen negative electrode material, and the corresponding current collector is copper. This windowing can prevent the XRD diffraction optical path of the test electrode sheet from being blocked by the positive electrode case 91 and increase the accuracy of in-situ testing.

[0047] The present application also provides an X-ray diffraction test device, which includes an X-ray source and the battery in-situ X-ray diffraction test assembly described above. The upper surface of the sample accommodation space is at the same working height as the X-ray source. Thus, by assembling the test battery sample 9 (such as a windowed button battery) into the sample accommodation space, crystal diffraction testing under in-situ electrochemical conditions can be achieved. In addition, for the battery sample 9 located in the sample accommodation space, its upper surface is at the same working height as the X-ray source, and the defined height ensures the test requirements and the accuracy of the diffraction angle.

[0048] In some embodiments, the X-ray source is a low-energy X-ray source. For example, the X-ray tube is a Cu target. Thus, this device is suitable for crystal diffraction testing in the reflection mode under low-energy X-rays. The X-ray diffraction test device can use a common XRD sample stage, which is not particularly limited herein. When the X-ray diffraction test device tests the battery sample, it can perform in-situ characterization of the crystal diffraction of the positive electrode material or the negative electrode material in the battery sample in the state of loading in-situ electrochemistry, and obtain test information such as the interplanar spacing, intensity, and peak position under different charged states, that is, it is suitable for crystal structure analysis and material electrochemical performance analysis of battery materials.

[0049] In some embodiments, the X-ray diffraction test device further includes a charge-discharge instrument, which is used to be electrically connected to the second electrode 3 and the first electrode 4 in the in-situ X-ray diffraction test assembly of the battery to apply a current, so as to realize the in-situ test of the battery sample 9 in the sample accommodation space.

[0050] The in-situ X-ray diffraction test device of the present application has at least one of the following advantages: the device can avoid using Kapton film or Be encapsulation for the battery to be tested, and by using the battery sample with a window design to replace the Kapton film or Be encapsulation, the test analysis of the reflection mode of materials at low energy is realized; the in-situ XRD test of this device has better test data consistency and repeatability compared with the test of Swagelok-type batteries, and does not use highly toxic Be, with low sample production cost, short cycle and high test success rate; the device is independent of other device hardware, and can realize fast and convenient on-machine analysis without shutting down the device and replacing the sample stage, and the test experimental data has good stability and high consistency.

[0051] Example 1

[0052] 1. In-situ X-ray diffraction test assembly of the battery and X-ray diffraction test device:

[0053] An X-ray diffractometer (XRD), model Bruker D8 ADVANCE, with a sample stage model of Flipstick, an X-ray tube with a Cu target, and a Blue Power battery test system of CT3002A are provided.

[0054] Reference Figures 1 to 7 , an in-situ X-ray diffraction test assembly of the battery is provided, with an outer diameter of 51.5 mm, a height of 12 mm, both the cover and the base are made of PEEK, the cover is slotted 10 mm, and the whole assembly is fastened with 4 cross-recessed head screws (model SUS304-M3×8). The first through hole and the second through hole, that is, the positive electrode wire jack and the negative electrode wire jack, have a diameter of 2 mm and a depth of 10.8 mm, and the included angle is 20°. The corresponding positions of the first through hole and the second through hole are used to connect the wire plugs. That is, the positive electrode wire and the negative electrode wire in the positive electrode wire jack and the negative electrode wire jack use a 4-core fixed aviation plug of model GX16, which is suitable for connection with the Blue Power battery test system CT3002A. The second electrode and the first electrode are made of red copper, with a size of 30 mm in diameter and 3 mm in thickness. This in-situ X-ray diffraction test assembly of the battery can be assembled and adapted to the sample stage in the X-ray diffractometer to form an X-ray diffraction test device.

[0055] 2. Battery sample to be tested:

[0056] Reference Figure 8The upper surface height of the battery sample to be tested is 8.5 mm, which is suitable for the sample analysis height of the X-ray diffractometer. The model of the battery sample to be tested is a CR2032 window button battery.

[0057] The steps for making a window button battery are as follows: (1) placing a polyvinylidene fluoride (PVDF) binder in an oven and baking it, then transferring it to a drying dish and sealing it for cooling; ultrasonicating the battery shell with anhydrous ethanol for 30 minutes and vacuum drying it before use; cutting the electrode to be tested into discs with a diameter of 16 mm, removing abnormal pieces and vacuum baking them at 115°C for 6 hours for later use; weighing about 46.75 g of N-methylpyrrolidone (NMP) and 3.25 g of PVDF binder for later use, adding PVDF to the weighed NMP while stirring, and preparing a uniform, bubble-free glue solution with a solid content of 6.5%. (2) Use the tip of a toothpick to dip into 6.5% PVDF glue, pass the toothpick through the opening, and evenly scrape about 1mm wide glue on the opening of the 5mm window positive electrode shell; use tweezers to place the electrode to be tested in the middle of the shell, and use a cotton swab to gently press the electrode to be tested so that the electrode to be tested is fully in contact with the PVDF glue; cover the electrode to be tested with a stainless steel gasket and anode shell in turn (note: the smooth surface of the stainless steel faces the positive electrode side), and gently press the anode shell; transfer the above assembly to the middle of the stainless steel rod, the seam width of the stainless steel rod must be larger than the opening diameter, and place it in a vacuum oven at 115℃ for 6 hours. (3) Transfer the baked assembly to the glove box; gently pour out the anode shell and gasket in the assembly, and place dust-free paper underneath during assembly to ensure insulation; clean the surface of the lithium sheet with a toothbrush to remove the passivation film. (4) Assemble in the following order: positive electrode shell, electrode to be tested, diaphragm, lithium sheet, gasket, negative electrode shell. Before placing the electrode to be tested, 50 μL of electrolyte needs to be dripped on the diaphragm. (5) Place the battery on the shell sealing machine with the positive electrode facing downward, shake the handle until the pressure reaches 520±50 kPa and stop, maintain the pressure for 3 seconds, complete the shell sealing, and manually wipe the residual electrolyte on the battery with dust-free paper after sealing; put the assembled batteries into the battery box according to the number to prevent confusion. Among them, the electrode to be tested includes a current collector and a layer of active material to be tested arranged on the surface of the current collector, the active material to be tested faces the diaphragm (i.e., the window away from the positive electrode shell), the current collector can be aluminum, and the active material layer to be tested includes the active material to be tested, and the active material to be tested can be a nickel-cobalt-manganese NCM ternary positive electrode active material. Among them, the electrode to be tested can be prepared by the following steps: the active material to be tested, lithium nickel-cobalt-manganese oxide (LiNi 0.9 Co 0.05 Mn 0.05 O 2 ): polyvinylidene fluoride (PVDF): conductive carbon black (SP), by weight ratio = 90:5:5, the initial solid content is set to 43%, in N-methylpyrrolidone NMP, after being fully homogenized, it is coated on a 12μm thick aluminum current collector, and then dried, rolled, hot pressed and other steps to obtain the electrode to be tested.

[0058] 3. In-situ electrochemical analysis:

[0059] Place the prepared battery sample to be tested (open-window button battery) between the cover 1 and the base 2 of the battery in-situ X-ray diffraction test assembly. After tightening the screws, clamp the test assembly on the sample stage of the X-ray diffractometer. The open window of the open-window button battery faces upward, exposing the current collector coated with the active material layer to be tested. The open-window button battery is connected to the second electrode and the first electrode of the test assembly, and is connected to a charge-discharge instrument through an external interface via a second wire and a first wire to apply a current. Place this in-situ cell device on the XRD sample stage for in-situ analysis to realize the in-situ characterization of the crystal diffraction information of the active material.

[0060] Turn off the rotation function of the sample stage to prevent the wires from changing positions during the test. Place the air scattering screen of the XRD in a suitable position. Set the working steps of the charge-discharge instrument, and set the XRD scanning angle range, step size, acquisition time per point, and the number of cyclic acquisition circles. Start the XRD and the charge-discharge instrument simultaneously for scanning analysis and record the in-situ data. Figure 9 It is the XRD-potential-time curve for the in-situ analysis (during charge and discharge) of the NCM ternary cathode active material to be tested.

[0061] Although some exemplary embodiments of the present application have been described and illustrated, the present application is not limited to the disclosed embodiments. On the contrary, those of ordinary skill in the art will recognize that some modifications and changes can be made to the described embodiments without departing from the spirit and scope of the present application as described in the appended claims.

Claims

1. A battery in-situ X-ray diffraction test assembly, characterized in that: include: A base, wherein the base is provided with a first accommodation space; a first electrode, the first electrode being arranged at the bottom of the first containing space; A cover body, wherein the upper surface of the cover body has a first groove, the lower surface of the cover body has a second accommodation space connected with the first groove, the cover body is arranged opposite to the base and is detachably connected, and the second accommodation space is connected with the first accommodation space; a second electrode, wherein the upper surface of the second electrode has a second groove, the lower surface of the second electrode has a third accommodation space communicated with the second groove, the second electrode is arranged in the second accommodation space and spaced apart from the first electrode, and the second groove is communicated with the first groove; The third containing space is communicated with the first containing space, and defines a sample containing space with the second electrode and the first electrode.

2. The battery in-situ X-ray diffraction test assembly according to claim 1, characterized in that: The base and the cover are provided with screw holes, and screws are provided in the screw holes to fix the base and the cover; and / or The first electrode is electrically connected to a first wire, the base has a first through hole, and the first wire passes through the first through hole and extends to the outside of the base; and / or The second electrode is electrically connected to a second wire, the cover has a second through hole, and the second wire passes through the second through hole and extends to the outside of the cover.

3. The battery in-situ X-ray diffraction test assembly according to claim 2, characterized in that: The base is a column; and / or Along the base toward the cover, the first accommodation space includes a first cavity and a second cavity that are connected, the lateral width of the first cavity is greater than the lateral width of the second cavity, and the first electrode is located in the first cavity.

4. The battery in-situ X-ray diffraction test assembly according to claim 3, characterized in that: The outer wall of the base has a circumferential annular groove, and the first through hole is arranged on the annular groove; and / or The first electrode is a cylinder, and the orthographic projection of the second electrode on the first electrode is located in the area where the first electrode is located; and / or The orthographic projection of the second electrode on the first electrode is located in the region where the orthographic projection of the second cavity on the first electrode is located; and / or The lateral width of the second cavity is greater than the lateral width of the third accommodating space.

5. The battery in-situ X-ray diffraction test assembly according to claim 4, characterized in that: The first groove transversely penetrates the upper surface of the cover body, and along the transverse penetration direction of the first groove, the first groove includes a first groove, a second groove and a third groove; and / or The second groove transversely penetrates the upper surface of the second electrode.

6. The battery in-situ X-ray diffraction test assembly according to claim 5, characterized in that: The orthographic projections of the first groove and the third groove on the second electrode are located in the second groove, and the orthographic projection of the second groove on the second electrode is at least partially located outside the second groove; and / or The upper surface of the second electrode is exposed on the upper surface of the cover body through the second groove; and / or An orthographic projection of the second groove on the first electrode coincides with an orthographic projection of the third accommodation space on the first electrode.

7. The battery in-situ X-ray diffraction test assembly according to claim 1, characterized in that: The sample containing space is used to contain a battery sample. The upper surface of the battery sample is electrically connected to the second electrode, and the lower surface of the battery sample is electrically connected to the first electrode.

8. The battery in-situ X-ray diffraction test assembly according to claim 7, characterized in that: The type of the battery sample is a windowed button battery; and / or When the battery sample is located in the sample accommodating space, the upper surface of the battery sample is a positive electrode shell having an opening, and the battery sample includes a pole piece to be tested, which is exposed on the upper surface of the cover body through the opening, the second groove, and the first groove in sequence.

9. The battery in-situ X-ray diffraction test assembly according to claim 8, characterized in that: The battery sample includes a positive electrode shell, a test electrode sheet, a separator, a lithium sheet, a gasket, a spring and a negative electrode shell which are stacked in sequence; wherein the test electrode sheet includes a current collector and an active material layer to be tested which is arranged on the surface of the current collector, the active material layer to be tested faces the separator, the active material layer to be tested includes an active material to be tested, and the active material to be tested is a positive electrode active material or a negative electrode active material.

10. An X-ray diffraction testing device, characterized in that: include: An X-ray source and a battery in-situ X-ray diffraction test assembly as claimed in any one of claims 1 to 9, wherein the upper surface of the sample containing space is the same as the working height of the X-ray source.

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