Spectrum pool for in-situ detection combination

Abstract

The utility model provides a spectrum pool combined with in-situ detection, which is used for an all-solid-state battery and is characterized in that the in-situ detection comprises in-situ Raman detection, in-situ XRD detection and in-situ optical microscope detection; the spectrum pool comprises a spectrum pool body and a detection window cover, the spectrum pool body is provided with a female die cavity for accommodating a battery to be detected, the female die cavity is provided with a window, and the detection window cover is mounted relative to the window; when the to-be-tested battery is accommodated in the cavity of the female die, the three-phase cross section of the to-be-tested battery is exposed out of the window; and the detection window cover and the spectrum cell body are detachably mounted.

Description

Technical Field

[0001] The utility model relates to the technical field of electrochemistry, in particular to a spectral cell used for in-situ detection. Background Art

[0002] In recent years, due to the increasing demand for building ultra-high energy density and high safety secondary batteries, all-solid-state batteries that use non-flammable solid electrolytes to replace flammable liquid electrolytes have become the primary approach. With the continuous development of solid-state batteries, people have found that polymer-based solid electrolytes composed of ethylene oxide (PEO) polymers and alkali metal salts (TFSI) have high safety and good processability. At the same time, inorganic solid electrolytes usually have high ionic conductivity, high modulus, high electrochemical stability window and excellent thermal stability. Therefore, all-solid-state batteries using solid electrolytes have received widespread attention in recent years.

[0003] Among them, many interfaces inside the all-solid-state battery, including the interface between the solid electrolyte and the positive electrode, the interface with the negative electrode, and the interface between the solid electrolyte particles (grain boundary), have a very important impact on the electrochemical performance of the battery. In order to further improve the comprehensive performance of all-solid-state batteries, it is necessary to fundamentally understand the stability of the solid-solid electrochemical interface during the all-solid-state battery reaction process.

[0004] Modern in-situ characterization technology provides technical support for studying the operating mechanism of all-solid-state batteries during the reaction process by characterizing the running battery with high time resolution. At present, among the various characterization methods in the solid-state battery reaction process, in-situ XRD can monitor the changes in the phase and lattice parameters of the electrode or electrode-electrolyte interface in real time during the battery's charge and discharge cycle, providing important perspectives and data support for in-depth research on the operation and failure mechanism of the battery. In-situ Raman can be used to detect changes in the material composition and structure of the electrode or solid electrolyte surface in all-solid-state batteries, and in-situ optical microscopy can intuitively observe the changes in the particle size and morphology of the electrode material during the cycle at a microscopic scale.

[0005] However, the current spectral cell devices used to test solid-state batteries have relatively simple functions and can only be used for a single in-situ test. This is because a spectral cell that can combine multiple characterization techniques such as in-situ XRD, in-situ Raman, and in-situ optical lenses is in great need.

[0006] At the same time, the core challenges of the surface interface of solid-state batteries are currently concentrated in three aspects: first, the transport mechanism of ions at the solid-solid multiphase interface is unknown; second, the evolution law and failure mechanism of the multi-field coupling of the solid-solid interface are unclear; third, the physical and chemical process of deposition and stripping on the surface interface of the conversion-type lithium-based negative electrode is unclear.

[0007] However, in the spectral cells currently used for in-situ characterization, often only the positive electrode or the negative electrode of the battery to be tested is exposed to the observation window, so only the transport mechanism of the single-phase interface of the positive electrode or the negative electrode can be observed, and it is impossible to simultaneously characterize the positive, negative electrodes, electrolyte three phases and their surface interfaces in a large field of view.

[0008] Therefore, in order to address the surface and interface problems in the reaction process of solid-state batteries, we have developed a combination of multiple in-situ characterization techniques and a wide-field characterization method to simultaneously characterize the three phases of the positive electrode, electrolyte, and negative electrode and their surface and interface. This is of great significance for clarifying the solid-solid interface reaction and structural evolution mechanism throughout the life cycle and guiding the design of solid-state batteries. Utility Model Content

[0009] The technical problem to be solved by the utility model is to provide a spectral cell for in-situ detection, which can combine the three important characterizations in the battery field, namely in-situ XRD, in-situ Raman and in-situ optical microscopy, and can characterize the positive electrode, electrolyte and negative electrode three phases and their surface interfaces at the same time.

[0010] In order to solve the above technical problems, the utility model provides a spectrum cell for in-situ detection, which is used for all-solid-state batteries. The in-situ detection includes in-situ Raman detection, in-situ XRD detection, and in-situ optical microscope detection. The spectrum cell includes a spectrum cell body and a detection window cover. A concave mold cavity for accommodating a battery to be tested is arranged on the spectrum cell body. A viewing window is provided in the concave mold cavity. The detection window cover is installed relative to the viewing window.

[0011] When the battery to be tested is accommodated in the cavity of the concave mold, the three-phase cross section of the battery to be tested is exposed to the viewing window; the detection window cover and the spectrum cell body are detachably mounted.

[0012] In some embodiments, a first current collector and a second current collector are further included, wherein the first current collector and the second current collector are assembled to form a receiving cavity for receiving the battery to be tested, and the receiving cavity is received in the concave mold cavity.

[0013] In some embodiments, conductive top rods are provided on both sides of the spectral cell body for externally connecting to an electrochemical workstation, and the conductive top rods on both sides penetrate into the cavity of the concave mold and are respectively conductively connected to the first current collector and the second current collector.

[0014] In some embodiments, the conductive push rod is movable along its length direction to push the first current collector and the second current collector to pressurize the battery to be tested.

[0015] In some embodiments, a limiting groove having the same shape as the end surface of the conductive top rod is provided on the outer side surface of the first current collector and the second current collector, and the conductive top rod is inserted into the limiting groove to be conductively connected with the first current collector and the second current collector.

[0016] In some embodiments, a U-shaped insulating limit block is provided between the first current collector and the second current collector, the opening of the U-shaped insulating limit block is arranged toward the detection window cover, and the battery to be tested is accommodated in the space formed by the U-shaped insulating limit block.

[0017] In some embodiments, a U-shaped groove having the same shape as the U-shaped insulating limit block is provided on the side facing each other of the first current collector and the second current collector, and the sum of the depths of the U-shaped grooves of the first current collector and the second current collector is less than the depth of the space formed by the U-shaped insulating limit block.

[0018] In some embodiments, the space formed by the U-shaped insulating limit block is consistent with the size of the battery to be tested.

[0019] In some embodiments, a circle of mounting grooves is provided above the spectral pool body, the mounting grooves are provided on the outer periphery of the cavity of the concave mold, a threaded ring is provided on the inner wall of the mounting groove, the detection window cover is provided with threads corresponding to the threaded ring, and the threads are installed on the spectral pool body.

[0020] In some embodiments, a sealing gasket is provided at the bottom of the groove, a sealing ring limiting groove is provided above the spectrum pool body, a sealing ring is built into the sealing ring limiting groove, and the sealing ring limiting groove is provided on the outer side of the die cavity and the inner side of the installation groove.

[0021] Compared with the prior art, the beneficial effects of the present invention include:

[0022] 1. The detection window cover and the spectral cell body are detachably installed. By replacing the detection window covers of different in-situ characterization technologies, such as the XRD detection window cover and the Raman detection window cover, multiple in-situ characterization technologies can be combined for the solid-state battery without disassembling the solid-state battery. At the same time, when the battery to be tested is placed in the cavity of the concave mold, the three-phase cross-section of the battery to be tested is exposed to the window of the cavity of the concave mold, so that the positive electrode, electrolyte, negative electrode three phases and their surface interfaces can be characterized in a wide field of view at the same time.

[0023] 2. The pole piece and electrolyte of the battery to be tested are limited and wrapped by the U-shaped insulating limit block to avoid short circuit between the positive and negative electrodes of the battery to be tested, and to prevent the pole piece and electrolyte of the battery to be tested from being misaligned, resulting in uneven three-phase cross-section. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the spectrum pool of the utility model;

[0025] Figure 2 It is a cross-sectional view when the Raman detection window cover 4 is installed;

[0026] Figure 3 It is a cross-sectional view when the XRD detection window cover 10 is installed.

[0027] Figure numerals: 1. conductive top rod; 2. sealing ring limit groove; 3. ultra-thin quartz window; 4. Raman detection window cover; 5. circular perforation; 6. spectral cell body; 7. first current collector; 8. U-shaped insulating limit block; 9. sealing gasket; 10. XRD detection window cover; 11. Raman detection window cover wrench; 12. second current collector. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model without making creative work are within the scope of protection of the utility model.

[0029] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "installed / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0031] In the field of in-situ characterization technology of all-solid-state batteries, current in-situ detection spectral cell devices can often only perform single-type in-situ detection. When multi-dimensional detection such as in-situ XRD, in-situ Raman, and in-situ optical lens detection is required for solid-state batteries, the tested all-solid-state battery needs to be disassembled from the spectral cell device. The operation is complicated and destructive, which can easily lead to inaccurate test results. At the same time, when the all-solid-state battery to be tested is loaded into the spectral cell, often only the positive or negative electrode is exposed to the window, and it is impossible to simultaneously perform large-field in-situ detection of the positive, negative, and electrolyte phases of the battery and their interfaces.

[0032] To solve the above problems, refer to Figures 1 to 3 , this embodiment provides a spectral cell for in-situ detection, which is used for in-situ detection of all-solid-state batteries, wherein the in-situ detection includes in-situ Raman detection, in-situ XRD detection, and in-situ optical microscope detection;

[0033] The spectrum cell comprises a spectrum cell body 6 and a detection window cover. A concave mold cavity for accommodating a battery to be tested is arranged on the spectrum cell body 6. The concave mold cavity is provided with a rectangular window for exposing the battery to be tested to an in-situ testing instrument. The window and the detection window cover are arranged opposite to each other. The detection window cover is used to transmit XRD rays or Raman lasers or expose the field of view of an in-situ optical microscope.

[0034] The battery to be tested is placed in the accommodating cavity formed by the first current collector 7 and the second current collector 12 and then placed in the cavity of the concave mold. When the battery to be tested is accommodated in the cavity of the concave mold, the three-phase cross-sections of the positive electrode, the negative electrode, and the electrolyte of the battery to be tested are exposed to the window, so that the three phases of the battery to be tested can be simultaneously exposed to the in-situ Raman laser or XRD ray or the field of view of the in-situ optical microscope.

[0035] Circular through holes are provided on both sides of the spectral cell body 6, and conductive top rods 1 are penetrated through the through holes. The conductive top rods 1 on both sides penetrate into the cavity of the die and are respectively conductively connected to the first current collector 7 and the second current collector 12. Specifically, the conductive top rod 1 is provided with pole ears for connecting with an external electrochemical workstation, and the sides of the first current collector 7 and the second current collector 12 facing the conductive top rod 1 are provided with limiting grooves consistent with the end face shape of the conductive top rod 1. The conductive top rod 1 is inserted into the limiting groove and is conductively connected to the first current collector 7 and the second current collector 12.

[0036] In order to ensure good contact between the positive electrode, negative electrode, electrolyte of the battery to be tested and the first current collector 7 and the second current collector 12 on both sides, and ensure smooth reaction process, the front end of the conductive push rod 1 is provided with a high-density thread, and the conductive push rod 1 is connected to the spectrum cell body 6 through the front end thread, and the conductive push rod 1 is rotated so that the conductive push rod 1 can move forward and backward along its length direction, and the length of the conductive push rod 1 screwed into the cavity of the concave mold is controlled to push the first current collector 7 and the second current collector 12 to pressurize the battery to be tested, so as to ensure good contact between the battery materials of the battery to be tested;

[0037] The middle end of the conductive top rod 1 is a smooth cylinder, and sealing rings are arranged around the circular through hole 5. After the conductive top rod 1 is screwed in, the smooth cylinder at the middle end of the conductive top rod 1 is placed in the circular through hole 5, and the smooth cylinder and the sealing ring are squeezed to maintain the air tightness of the spectrum cell body 6.

[0038] In order to ensure good contact between the battery materials of the battery to be tested, when the first current collector 7 and the second current collector 12 are pushed by the conductive push rod 1 to pressurize the battery to be tested, because some negative electrode materials are very soft, when pressure is applied, the negative electrode material will be deformed due to stress and overflow from the side, causing contact with the positive electrode, thereby causing a short circuit.

[0039] In order to ensure that a short circuit does not occur due to contact between the positive and negative electrodes when the battery pole pieces are installed, in the present embodiment, a U-shaped insulating limit block 8 is provided between the first current collector 7 and the second current collector 12, and the opening of the U-shaped insulating limit block 8 is arranged toward the detection window cover; at the same time, a U-shaped groove consistent with the shape of the U-shaped insulating limit block 8 is provided on the side facing each other of the first current collector 7 and the second current collector 12; the sum of the depths of the U-shaped grooves of the first current collector 7 and the second current collector 12 is less than the depth of the space formed by the U-shaped insulating limit block 8, so that when the U-shaped insulating limit block 8 is embedded in the first current collector 7 and the second current collector 12, the U-shaped insulating limit block 8 still has a accommodating space for accommodating the battery to be tested, and the accommodating space formed by the U-shaped insulating limit block 8 is consistent with the size of the battery to be tested.

[0040] When the battery to be tested is placed in the accommodating space, the conductive push rod 1 pushes the first current collector 7 and the second current collector 12, and the protrusions formed inside the U-shaped grooves of the first current collector 7 and the second current collector 12 pressurize the battery to be tested. Since the U-shaped insulating limit block 8 surrounds the electrode piece of the battery to be tested, the negative electrode material is not easily exposed from the side and contacts the positive electrode when it is uniformly pressed by the protrusion, thereby preventing a short circuit.

[0041] At the same time, when the pole piece is located in the accommodation space in the U-shaped insulating limit block 8, the size and shape of the pole piece are consistent with the accommodation space in the U-shaped insulating limit block 8, and the side of the U-shaped insulating limit block 8 and the pole piece and electrolyte of the battery to be tested are limited in the vertical direction and horizontal front and rear direction, which prevents the pole piece from being misaligned during the pressurization process. The bottom of the U-shaped insulating limit block 8 supports the battery to be tested, and also prevents the pole piece and electrolyte material from sinking when placed vertically, thereby causing the three-phase cross section exposed in the window window to be not on the same horizontal plane. Among them, the U-shaped insulating limit block 8 is made of insulating high-hardness PEEK material.

[0042] In this embodiment, a circle of mounting grooves is arranged above the spectrum cell body 6, and the mounting grooves are arranged on the periphery of the cavity of the die. A threaded circle is arranged on one side of the inner wall of the mounting groove, and a thread corresponding to the threaded circle is arranged on the outer side of the detection window cover, and the detection window cover is detachably mounted on the spectrum cell body 6 through the thread. When in use, the detection window cover can be replaced and disassembled according to the specific in-situ detection type. For example, when performing in-situ XRD detection, the detection window cover adopts an XRD detection window cover 10, and the rays of the in-situ XRD instrument pass through the XRD detection window cover 10 through the window window and focus on the three-phase cross section of the battery to be tested for detection. When performing in-situ Raman detection and in-situ optical microscope detection, the original XRD detection window cover 10 can be disassembled and replaced with a Raman detection window cover 4. The cover of the Raman detection window cover 4 adopts an ultra-thin quartz window 3 with a thickness of less than 0.5 mm, which can pass through the Raman laser and expose the field of view of the in-situ optical microscope, so as to detect the three-phase cross section of the battery to be tested. At the same time, the Raman detection window cover 4 is also provided with a Raman detection window cover wrench 11 for convenient rotation and disassembly.

[0043] In order to ensure the airtightness of the entire spectrum pool, a sealing gasket 9 is arranged at the bottom of the groove, a sealing ring limiting groove 2 is arranged above the spectrum pool body 6, the sealing ring limiting groove 2 has a built-in sealing ring, and the sealing ring limiting groove 2 is arranged on the outside of the cavity of the die and the inside of the installation groove. When the detection window cover is screwed into the spectrum pool body 6, the sealing ring and the Raman detection window cover 4 are squeezed to ensure the airtightness of the spectrum pool; and the XRD detection window cover 10 is a structure composed of a hemispherical shell and a circular ring tangent to each other, and the upper hemispherical shell cannot be squeezed with the sealing ring, so the sealing gasket 9 in the groove can ensure the airtightness of the installation position. The sealing cover is made of insulating, high-hardness PEEK material.

[0044] When the battery under test is tested in situ, the following steps are included:

[0045] 1) Cut or die-cut the prepared positive electrode, negative electrode, and solid electrolyte into squares of the same size as the accommodating space of the U-shaped insulating limit block 8 for standby use;

[0046] 2) Take out the first current collector 7, install the U-shaped insulating stopper 8 into the first current collector 7, and evenly spread the prepared positive electrode, electrolyte, and negative electrode on the surface of the first current collector 7 and on the U-shaped insulating stopper 8 in sequence, and then take out the second current collector 12 and install it on the U-shaped insulating stopper 8 with electrode and electrolyte materials;

[0047] 3) Loading the assembled battery materials, the first current collector 7, the second current collector 12, and the U-shaped insulating stopper 8 into the cavity of the concave mold through the rectangular window above the spectrum cell body 6;

[0048] 4) The conductive push rod 1 and the sealing ring are installed into the spectrum cell body 6 through the perforation of the conductive push rod 1 matching the spectrum cell body 6, the conductive push rod 1 and the pressurized current collector are tightly connected by the thread, the thread is tightened by a wrench, and pressure is applied to the positive electrode, the solid electrolyte, and the negative electrode through the pressurized current collector to ensure good contact of the battery materials;

[0049] 5) The optical microscope, Raman sealing cover, ultra-thin quartz window 3 and sealing ring are installed on the top of the spectral cell body 6 through threads, and the ultra-thin quartz window 3 and the sealing ring are pressed by tightening the threads to ensure the sealing effect; an external electrochemical workstation is connected to the conductive push rod 1, relevant electrochemical operations are performed on the spectral cell, and in-situ characterization is performed using an in-situ optical microscope.

[0050] 6) After the in-situ optical microscope characterization is completed, the optical microscope is removed while maintaining the electrochemical operation, and an in-situ Raman spectrometer is used to perform in-situ Raman detection.

[0051] 7) After the Raman characterization is completed, while maintaining the electrochemical operation, remove the optical microscope and the Raman sealing cover, replace the XRD sealing cover and the sealing gasket 9, install them on the top of the spectrum cell body 6 through threads, and apply pressure to the sealing gasket 9 by tightening the threads to ensure the sealing effect, and perform in situ characterization under the XRD instrument.

[0052] The spectrum cell used for in-situ detection provided in this embodiment is detachably mounted on the spectrum cell body 6 through the detection window cover, so as to realize the combination of three characterization methods, namely, in-situ optical microscopy, in-situ XRD detection, and in-situ Raman detection. The same solid-state battery can be characterized by three methods without disassembling the battery. At the same time, optical lenses of different magnifications and different Raman spectrometers can be used for detection. The hemispherical shell of XRD can realize the characterization of the full range of diffraction angles.

[0053] At the same time, by exposing the three-phase cross section to the window, the positive electrode, negative electrode, electrolyte and their interface can be simultaneously characterized horizontally with a large field of view, such as line scanning Raman, wide-field Raman, and optical microscopy observation.

[0054] The assembly process and pressurization method of the spectral cell are simple, all parts can be disassembled and cleaned, and it is small in size and light in weight, which facilitates repeated characterization and testing. It can be applied to solid-state batteries of various thicknesses and different material systems, which is conducive to studying the surface and interface problems of solid-state batteries, clarifying the solid-solid interface reaction and structural evolution mechanism during the life cycle, and then guiding the design of solid-state batteries.

[0055] The above is only a preferred specific implementation method of the utility model, but the design concept of the utility model is not limited to this. Any technician familiar with the technical field who uses this concept to make non-substantial changes to the utility model within the technical scope disclosed by the utility model shall be deemed to infringe the protection scope of the utility model.

Claims

1. A spectral cell for in-situ detection, used for all-solid-state batteries, characterized in that: The in-situ detection includes in-situ Raman detection, in-situ XRD detection, and in-situ optical microscope detection; the spectrum cell includes a spectrum cell body and a detection window cover, the spectrum cell body is provided with a concave mold cavity for accommodating the battery to be tested, the concave mold cavity is provided with a viewing window, and the detection window cover is installed relative to the viewing window; When the battery to be tested is accommodated in the cavity of the concave mold, the three-phase cross section of the battery to be tested is exposed to the viewing window; the detection window cover and the spectrum cell body are detachably mounted.

2. The spectral cell for in-situ detection according to claim 1, characterized in that: It also includes a first current collector and a second current collector, wherein the first current collector and the second current collector are assembled to form a receiving cavity for receiving the battery to be tested, and the receiving cavity is received in the cavity of the concave mold.

3. The spectral cell for in-situ detection according to claim 2, characterized in that: Conductive top rods are arranged on both sides of the spectral cell body for externally connecting to an electrochemical workstation. The conductive top rods on both sides penetrate into the cavity of the concave mold and are respectively conductively connected to the first current collector and the second current collector.

4. The spectral cell for in-situ detection according to claim 3, characterized in that: The conductive push rod is movable along its length direction to push the first current collector and the second current collector to pressurize the battery to be tested.

5. The spectral cell for in-situ detection according to claim 4, characterized in that: A limiting groove having the same shape as the end surface of the conductive top rod is provided on the outer side surfaces of the first current collector and the second current collector, and the conductive top rod is inserted into the limiting groove to be conductively connected with the first current collector and the second current collector.

6. The spectral cell for in-situ detection according to claim 2, characterized in that: A U-shaped insulating limit block is disposed between the first current collector and the second current collector, the opening of the U-shaped insulating limit block is disposed toward the detection window cover, and the battery to be tested is accommodated in a space formed by the U-shaped insulating limit block.

7. The spectral cell for in-situ detection according to claim 6, characterized in that: A U-shaped groove having the same shape as the U-shaped insulating stopper is provided on the opposite sides of the first current collector and the second current collector, and the sum of the depths of the U-shaped grooves of the first current collector and the second current collector is less than the depth of the space formed by the U-shaped insulating stopper.

8. The spectral cell for in-situ detection according to claim 6, characterized in that: The space formed by the U-shaped insulating limit block is consistent with the size of the battery to be tested.

9. The spectral cell for in-situ detection according to claim 1, characterized in that: A circle of mounting grooves is arranged above the spectral pool body, the mounting grooves are arranged on the outer periphery of the cavity of the concave mold, a threaded ring is arranged on the inner wall of the mounting groove, the detection window cover is provided with threads corresponding to the threaded ring, and the threads are installed on the spectral pool body.

10. The spectral cell for in-situ detection according to claim 9, characterized in that: A sealing gasket is arranged at the bottom of the groove, a sealing ring limiting groove is arranged above the spectrum pool body, a sealing ring is built in the sealing ring limiting groove, and the sealing ring limiting groove is arranged on the outer side of the concave mold cavity and the inner side of the installation groove.

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