Button cell device for in-situ electrochemical testing

Abstract

The utility model discloses a button cell device for in-situ electrochemical test, which comprises a shell, a positive plate, an isolation component and a negative plate, a cell inner cavity is formed in the shell, and a transparent observation window is arranged on the shell; the positive plate is provided with a positive observation hole; the isolation assembly comprises a diaphragm layer and a transparent blocking layer, a diaphragm through hole is formed in the diaphragm layer, and the transparent blocking layer is used for covering or blocking the diaphragm through hole; the active material layer of the negative plate faces the transparent observation window; the positive plate, the isolation assembly and the negative plate are sequentially stacked, and the transparent observation window, the positive observation hole and the diaphragm through hole are overlapped on the axial projection. Therefore, the behaviors of zinc dendrite growth and gassing side reaction of the active material on the negative plate can be observed in real time, so that a traditional button cell is transformed into a cell device suitable for in-situ electrochemical testing. In addition, the active materials of the positive plate and the negative plate can be prevented from being in direct contact through the transparent barrier layer, so that the problems of battery short circuit and the like are avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to a button battery device for in-situ electrochemical testing. Background Technology

[0002] In the field of rechargeable battery manufacturing, in-situ electrochemical testing of rechargeable battery systems is an indispensable and crucial step in battery research, development, production, and use. In-situ electrochemical testing refers to a testing method that monitors the performance and state of a battery in real time and dynamically during its charge and discharge states. For example, through in-situ electrochemical testing, the electrochemical performance of battery active materials, positive and negative electrode formulations, separators, and electrolyte formulations can be reasonably evaluated. Furthermore, from a fundamental research perspective, in-situ electrochemical testing helps to gain a deeper understanding of the charge-discharge mechanisms and failure mechanisms of positive and negative electrode materials in the battery system, which will contribute to further improving the chemical platform of rechargeable batteries. Therefore, in-situ electrochemical testing of rechargeable battery systems is indeed necessary.

[0003] In recent years, alkaline nickel-zinc batteries, as a very safe and reliable rechargeable battery technology, use aqueous alkaline electrolytes and possess characteristics such as high energy density, high power density, intrinsic safety, and environmental friendliness. They are expected to find widespread application in power tools, backup power supplies, emergency power supplies, home energy storage, and automotive start-stop systems. Although the technology of alkaline nickel-zinc batteries is developing rapidly and is very close to commercialization, many challenges remain to be solved, especially zinc dendrite growth and gas evolution side reactions at the negative electrode. Generally, the growth of zinc dendrites at the negative electrode can pierce the porous separator, causing short circuits and drastically shortening the battery's cycle life. Gas evolution side reactions at the negative electrode mainly generate hydrogen gas in the electrochemical environment, which can easily lead to electrolyte drying and battery leakage, directly affecting the lifespan of alkaline nickel-zinc batteries. In severe cases, the alkaline electrolyte may even damage electronic devices. Currently, to further improve zinc dendrite growth and gas evolution side reactions in the negative electrode, the electrochemical performance of alkaline nickel-zinc batteries can be significantly enhanced by optimizing the negative electrode active material, negative electrode formulation, and electrolyte composition. However, the mechanism behind this performance improvement still requires further in-depth research. In-situ electrochemical testing equipment can accurately reveal the morphological evolution of the negative electrode surface during charging and discharging in alkaline nickel-zinc battery systems.

[0004] As is well known, traditional button batteries, as a standard form of miniaturized battery, have advantages such as compact structure, ease of packaging, and portability, making them a very convenient electrochemical evaluation platform. Taking alkaline nickel-zinc batteries as an example, issues such as zinc dendrite growth and gas evolution side reactions at the negative electrode are crucial for evaluating the cycle life of alkaline nickel-zinc batteries, understanding failure mechanisms, and comprehending charge-discharge mechanisms. However, traditional button batteries are typically opaque, making it impossible to observe the zinc dendrite growth and gas evolution side reactions at the negative electrode of alkaline nickel-zinc batteries in real time during charge-discharge processes. Therefore, it is necessary to appropriately modify the structure of traditional button batteries to enable them to serve as devices for in-situ electrochemical testing of alkaline nickel-zinc batteries. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a button cell device for in-situ electrochemical testing, thereby enabling real-time dynamic observation of zinc dendrite growth and gas evolution side reactions at the negative electrode of alkaline nickel-zinc batteries.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A button cell device for in-situ electrochemical testing includes: a casing, a positive electrode, an isolation assembly, and a negative electrode. The casing contains a battery cavity, and a transparent observation window is provided on one end face of the casing. The positive electrode has a positive electrode observation hole. The isolation assembly includes a separator layer and a transparent barrier layer. The separator layer has a separator through-hole, and the transparent barrier layer is used to cover or block the separator through-hole. The active material layer of the negative electrode faces the transparent observation window. The positive electrode, the isolation assembly, and the negative electrode are stacked sequentially in the battery cavity. The positive electrode is located on the side closest to the transparent observation window, and the transparent observation window, the positive electrode observation hole, and the separator through-hole overlap in their axial projection.

[0008] In one embodiment, the transparent barrier layer is a transparent thin film layer located on the upper and / or lower surface of the diaphragm layer, and the transparent barrier layer is used to cover the diaphragm through-holes.

[0009] In one embodiment, the transparent film layer is a transparent alkali-resistant and high-temperature-resistant film layer.

[0010] In one embodiment, the transparent barrier layer is a transparent barrier block, which is disposed through the diaphragm through-hole and is used to block the diaphragm through-hole.

[0011] In one embodiment, the transparent barrier block is a transparent alkali-resistant and high-temperature-resistant barrier block.

[0012] In one embodiment, the size of the diaphragm through-hole is larger than the size of the positive electrode observation hole.

[0013] In one embodiment, the diaphragm through-hole has a circular structure and the diameter of the diaphragm through-hole is 1mm-3mm.

[0014] In one embodiment, the positive electrode observation aperture has a circular structure and a diameter of 0.5 mm to 1 mm.

[0015] In one embodiment, a gasket is also included, the gasket being located on the side of the positive electrode sheet near the transparent observation window, and the gasket having a gasket through hole, the transparent observation window, the gasket through hole, the positive electrode observation hole, and the diaphragm through hole overlapping in the axial projection.

[0016] In one embodiment, a spring sheet is also included, which is located on the side of the gasket near the transparent observation window, and the spring sheet has a spring sheet through hole. The transparent observation window, the spring sheet through hole, the gasket through hole, the positive electrode observation hole and the diaphragm through hole overlap in the axial projection.

[0017] Compared with the prior art, the present invention has at least the following advantages:

[0018] 1. The button battery device for in-situ electrochemical testing of this utility model has a transparent observation window on the casing, a positive electrode observation hole on the positive electrode, and a separator through hole on the separator layer. The active material layer on the negative electrode faces the transparent observation window. In this way, the zinc dendrite growth and gas evolution side reaction of the active material on the negative electrode can be observed in real time through the transparent observation window, the positive electrode observation hole, and the separator through hole. This transforms the traditional button battery into a device suitable for in-situ electrochemical testing of alkaline nickel-zinc batteries.

[0019] 2. The button battery device for in-situ electrochemical testing of this utility model adds a transparent barrier layer, which covers or seals the pores of the separator. This effectively prevents the active materials of the positive electrode from directly contacting the active materials of the negative electrode, thereby avoiding problems such as short circuits inside alkaline nickel-zinc batteries.

[0020] 3. The button battery device of this invention for in-situ electrochemical testing can realize a relatively realistic electrochemical charge-discharge environment, accurately reflecting the charge-discharge mechanism and failure mechanism of alkaline nickel-zinc batteries. This button battery device also helps to deepen the understanding of the mechanisms of action of negative electrode active materials, negative electrode formulations, and alkaline electrolyte additives. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below.

[0022] Figure 1 This is an exploded structural diagram of a button battery device for in-situ electrochemical testing according to an embodiment of the present invention.

[0023] Figure 2 This is an exploded structural diagram of a button battery device for in-situ electrochemical testing according to another embodiment of the present invention.

[0024] Figure 3 for Figure 1 A cross-sectional schematic diagram of a button cell device used for in-situ electrochemical testing.

[0025] Figure 4 This is a simplified diagram of an in-situ electrochemical testing system.

[0026] Figure 5 The figure shows the results of in-situ electrochemical testing of zinc dendrite growth and gas evolution side reactions on the surface of the negative electrode of an alkaline nickel-zinc battery. Detailed Implementation

[0027] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be given below with reference to the accompanying drawings.

[0028] Please see Figure 1 , Figure 2 and Figure 3 As shown, a button cell device 10 for in-situ electrochemical testing includes: a housing 100, a positive electrode 200, an isolation component 300, and a negative electrode 400. The housing 100 has a battery cavity, and a transparent observation window 111 is provided on one end face of the housing 100. The positive electrode 200 has a positive electrode observation hole 210. The isolation component 300 includes a separator layer 310 and a transparent barrier layer 320. The separator layer 310 has a separator through hole 311, and the transparent barrier layer 320 is used to cover or block the separator through hole 311. The active material layer 410 of the negative electrode 400 faces the transparent observation window 111. The positive electrode 200, the isolation component 300, and the negative electrode 400 are stacked sequentially in the battery cavity. The positive electrode 200 is located on the side close to the transparent observation window 111, and the transparent observation window 111, the positive electrode observation hole 210, and the separator through hole 311 overlap in the axial projection.

[0029] It should be noted that by setting up the casing 100 and forming a battery cavity on the casing 100, the positive electrode 200 and negative electrode 400 can undergo electrochemical reactions within the battery cavity. Simultaneously, to facilitate real-time observation of the zinc dendrite growth and gas evolution side reactions of the active material layer 410 of the negative electrode 400, a transparent observation window 111 is formed on the casing 100, a positive electrode observation hole 210 is formed on the positive electrode 200, and a separator through-hole 311 is formed on the separator layer 310. The transparent observation window 111, the positive electrode observation hole 210, and the separator through-hole 311 overlap in their axial projection, allowing light to sequentially pass through the transparent observation window 111, the positive electrode observation hole 210, and the separator through-hole 311, directly reaching the negative electrode 400. In this way, a traditional button cell battery can be transformed into a device suitable for in-situ electrochemical testing of alkaline nickel-zinc batteries, while simultaneously reflecting the battery's charging and discharging behavior in a realistic button cell environment. Please refer to [link to relevant documentation]. Figure 3 As shown, the overlapping of the transparent observation window 111, the positive electrode observation hole 210, and the diaphragm through hole 311 in the axial projection means that when projected along the central axis, the transparent observation window 111, the positive electrode observation hole 210, and the diaphragm through hole 311 partially or completely overlap, so that light can pass through the transparent observation window 111, the positive electrode observation hole 210, and the diaphragm through hole 311 respectively. For example, preferably, the centerlines of the transparent observation window 111, the positive electrode observation hole 210, and the diaphragm through hole 311 overlap. In this embodiment, the transparent observation window 111 can be a transparent quartz window.

[0030] It should also be noted that, in order to avoid direct contact between the active material of the positive electrode 200 and the active material of the negative electrode 400, and thus to prevent short circuits and other problems inside the battery, a transparent barrier layer 320 is added to the button battery device 10. The transparent barrier layer 320 serves to cover or seal the separator pores 311. For one embodiment, please refer to... Figure 1The diagram shows a transparent barrier layer 320 covering the through-hole 311 of the separator. The transparent barrier layer 320 is a transparent thin film layer located on the upper surface and / or lower surface of the separator layer 310, and the transparent barrier layer 320 is used to cover the through-hole 311 of the separator. That is, a transparent thin film layer can be attached to the upper or lower surface of the separator layer 310, or a transparent thin film layer can be provided on the upper and lower surfaces of the separator layer 310 respectively. By covering the through-hole 311 of the separator with the transparent thin film layer, the active material of the positive electrode 200 can be prevented from directly contacting the active material of the negative electrode 400. Taking alkaline nickel-zinc batteries as an example, since the electrochemical reaction environment of the battery is alkaline, in order to avoid corrosion and damage to the transparent film layer and to ensure the performance and service life of the transparent film layer, the transparent film layer is preferably a transparent alkali-resistant and high-temperature resistant film layer, such as polyethylene film, polypropylene film, polytetrafluoroethylene film, polystyrene film, polyimide plastic film, polyethylene terephthalate film, etc.

[0031] It should be further explained that, taking alkaline nickel-zinc batteries as an example, the casing 100 can be made of standard stainless steel button cell casing, and the models that can be used include: CR2012 (diameter 20mm, thickness 1.2mm), CR2025 (diameter 20mm, thickness 2.5mm), CR2032 (diameter 20mm, thickness 3.2mm), etc. The positive electrode 200 is coated on the surface of the nickel foam current collector with spherical nickel hydroxide, metallic nickel powder, conductive additives, binders, thickeners, and other materials. The diameter of the positive electrode 200 ranges from 14-16mm, and the thickness ranges from 0.2-0.5mm. The separator 300 is a plastic separator with a certain ability to absorb alkaline electrolyte and prevent zinc dendrite puncture. The material can be a porous separator composed of polypropylene or polyethylene, with a surface treated by sulfonation or grafting, and can be used to store alkaline electrolytes containing sodium hydroxide, lithium hydroxide, and potassium hydroxide. The diameter of the separator 300 ranges from 16-18 mm, and the thickness ranges from 100-250 μm. The concentration of hydroxide ions in the alkaline electrolyte ranges from 6-14 mol / L. The negative electrode 400 can be a tin-plated copper foil current collector coated with materials such as nano-zinc oxide, zinc powder, bismuth oxide, conductive additives, binders, and thickeners. It may also contain organic and inorganic additives to inhibit gas evolution side reactions and control zinc dendrite growth in the negative electrode 400. The diameter of the negative electrode 400 ranges from 12-15 mm, and the thickness ranges from 0.1-0.3 mm. It is important to note that the diameter of the negative electrode 400 needs to be slightly smaller than the diameter of the positive electrode 200, and the diameter of the separator 400 needs to be slightly larger than the diameters of both the positive and negative electrodes. This is mainly to avoid short circuits or micro-short circuits between the positive and negative electrodes 200, which would affect the in-situ electrochemical testing of the alkaline nickel-zinc battery performance.

[0032] In another implementation, please refer to Figure 2 As shown, the transparent barrier layer 320 is a transparent barrier block, which is inserted through the separator through-hole 311 and is used to seal the separator through-hole 311. That is, the transparent barrier block is inserted into the separator through-hole 311 to seal the separator through-hole 311, thereby preventing the active material of the positive electrode 200 from directly contacting the active material of the negative electrode 400. Taking an alkaline nickel-zinc battery as an example, similarly, the transparent barrier block is a transparent alkali-resistant and high-temperature resistant barrier block, such as a transparent barrier block made of materials such as polyethylene, polypropylene, polytetrafluoroethylene, polystyrene, polymethyl methacrylate, polycarbonate, polyimide, and polyethylene terephthalate.

[0033] Please see Figure 4 The diagram shows an in-situ electrochemical testing system, comprising a data acquisition device A, a charge / discharge apparatus B, an optical microscope C, and a button battery device 10. The data acquisition device A can be a computer or similar equipment. During in-situ electrochemical testing, the button battery device 10 is placed at the corresponding position on the optical microscope C. The charge / discharge apparatus B is connected to the positive and negative electrodes of the button battery device 10. Whether the button battery device 10 is in a static, activated, charging, or discharging state, the optical microscope C allows real-time observation of the zinc dendrite growth and gas evolution side reactions of the active material layer 410 of the negative electrode sheet 400 through the transparent observation window 111, the positive electrode observation hole 210, and the separator through-hole 311. Taking an alkaline nickel-zinc battery as an example, the charging method can be constant current charging to 1.9V, followed by current or time-based charging under a constant voltage of 1.9V. The constant current charging current can be 0.2C or 0.5C, the cutoff current can be 0.05C-0.2C, and the cutoff time can be 20-60 minutes. The discharge method can employ constant current discharge or constant power discharge. The constant current discharge current is typically 0.2-1C, with 0.5C or 1C discharge current recommended. The cutoff voltage can be 1.2-1.3V. It should be noted that the in-situ electrochemical testing system helps deepen the understanding of the charge-discharge mechanism and failure mechanism of alkaline nickel-zinc batteries, especially in revealing the role mechanism of negative electrode additives and electrolyte additives in the electrochemical environment. In-situ electrochemical research on failure mechanisms helps to propose targeted technical solutions to further improve the performance of alkaline nickel-zinc batteries. Furthermore, by using the in-situ electrochemical testing system to inject X-rays into the interior of the button cell device 10, the phase evolution process of the negative electrode of the alkaline nickel-zinc battery can also be studied.

[0034] In one embodiment, the size of the diaphragm through-hole 311 is larger than the size of the positive electrode observation hole 210. This avoids misalignment between the diaphragm through-hole 311 and the positive electrode observation hole 210 after assembly, which would reduce the field of view. Furthermore, in this embodiment, the transparent observation window 111 is larger than both the positive electrode observation hole 210 and the diaphragm through-hole 311. For example, in this embodiment, the diaphragm through-hole 311 has a circular structure, and its diameter ranges from 1mm to 3mm, preferably 2mm. Correspondingly, the positive electrode observation hole 210 has a circular structure, and its diameter ranges from 0.5mm to 1mm, preferably 0.75mm. It should also be noted that the diaphragm through-hole 311 and the positive electrode observation hole 210 can be circular, but are not limited to circular, and can also be quadrilateral, regular polygon or ellipse, etc.

[0035] Please see Figure 1 As shown, in one embodiment, the button battery device 10 further includes a gasket 500. The gasket 500 is located on the side of the positive electrode 200 near the transparent observation window 111, and a gasket through hole 510 is formed on the gasket 500. The transparent observation window 111, the gasket through hole 510, the positive electrode observation hole 210, and the separator through hole 311 overlap in the axial projection. By setting the gasket 500, the positive electrode 200, the separator 300, and the negative electrode 400 can be pressed and fixed, ensuring that the positive electrode 200, the separator 300, and the negative electrode 400 will not shake or shift in the battery cavity. At the same time, it can also improve the contact conductivity between the positive electrode 200 and the negative electrode 400 and the housing 100. Furthermore, it should be noted that the overlap of the transparent observation window 111, gasket through-hole 510, positive electrode observation hole 210, and separator through-hole 311 in axial projection refers to projection along the central axis. The transparent observation window 111, gasket through-hole 510, positive electrode observation hole 210, and separator through-hole 311 may partially or completely overlap, allowing light to pass through each of these components respectively. It should be noted that the gasket 500 can be made of stainless steel with a nickel-plated layer, the thickness of which ranges from 1-5 μm. The nickel plating effectively prevents corrosion of the gasket 500 in alkaline environments, thus protecting the charge and discharge performance of the alkaline nickel-zinc battery. The diameter of the gasket through-hole 510 is 4-5 mm, which is slightly larger than the diameter of the positive electrode observation hole 210 and the diaphragm through-hole 311, so as to facilitate in-situ electrochemical real-time observation of the zinc dendrite growth and gas evolution side reaction behavior on the surface of the negative electrode 400.

[0036] Please see Figure 1As shown, in one embodiment, the button battery device 10 further includes a spring 600. The spring 600 is located on the side of the pad 500 near the transparent observation window 111, and the spring 600 has a spring through hole 610. The transparent observation window 111, the spring through hole 610, the pad through hole 510, the positive electrode observation hole 210, and the separator through hole 311 overlap in axial projection. By setting the spring 600, the purpose is to further improve the contact tightness between the components inside the button battery cavity and the housing 100, thereby avoiding false contact that would affect the test results. It should be noted that the spring 600 can also be made of stainless steel with a nickel-plated layer on the surface, wherein the thickness of the nickel plating layer ranges from 1-5 μm. Similarly, the nickel plating layer can effectively prevent the spring 600 from corroding in an alkaline environment, thus affecting the charge and discharge performance of the alkaline nickel-zinc battery. The aperture of the spring sheet 600 is 4-5 mm, which is slightly larger than the diameter of the positive electrode observation hole 210 and the diaphragm through hole 311, making it convenient for in-situ electrochemical real-time observation of the zinc dendrite growth and gas evolution side reaction behavior on the surface of the negative electrode sheet 400.

[0037] Please see Figure 1 As shown, in one embodiment, a tin sheet 700 is further provided on the side of the negative electrode 400 away from the separator layer 310. The tin sheet 700 further ensures the conductivity between the negative electrode 400 and the casing 100. The tin sheet 700 can be made of metallic tin with a purity ≥99.9%, and its diameter ranges from 12-16 mm, and its thickness ranges from 0.2-0.8 mm. Its main purpose is to ensure good electrical contact inside the button cell, reduce the internal resistance of the button cell, and effectively suppress the gas evolution side reaction of the negative electrode.

[0038] In one embodiment, the housing 100 includes an upper cover 110 and a lower cover 120. A transparent observation window 111 is located on the upper cover 110. The positive electrode 200 is located on the side near the upper cover 110, and the negative electrode 400 is located on the side near the lower cover 120. Both the upper cover 110 and the lower cover 120 are made of stainless steel. The surface of the upper cover 110 can be plated with nickel, and the thickness of the nickel plating layer ranges from 1 to 5 μm. The surface of the lower cover 120 can be plated with tin, and the thickness of the tin plating layer ranges from 1 to 5 μm. This improves the corrosion resistance of the upper cover 110 and the lower cover 120 in an alkaline environment and effectively suppresses the gas evolution side reaction of the housing 100 in an electrochemical environment.

[0039] To further demonstrate the effectiveness of the in-situ electrochemical testing button battery device provided by this invention, taking an alkaline nickel-zinc battery as an example, the positive and negative electrodes use nickel hydroxide and zinc oxide as active materials, respectively. The alkaline electrolyte uses an alkaline solution with a hydroxide ion concentration of 7 mol / L, wherein sodium hydroxide, potassium hydroxide, and lithium hydroxide are used as alkaline electrolytes. The separator 300 uses a porous plastic film made of polyethylene and polypropylene with a thickness of 150 μm.

[0040] Figure 5 This image shows the results of in-situ electrochemical testing of zinc dendrite growth and gas evolution side reactions on the surface of the negative electrode of an alkaline nickel-zinc battery. Figure 5 (a) shows the initial state of the negative electrode surface. Optical microscopy results indicate that the surface of the negative electrode is relatively smooth. After the alkaline nickel-zinc battery undergoes the activation process, the negative electrode is in a charging state. Figure 5 (b) Optical microscopy results show that a large amount of metallic zinc is electrochemically deposited on the surface of the negative electrode, accompanied by gas generation. The charged nickel-zinc battery was discharged to 1.2V... Figure 5 (c) Optical microscopy results show obvious dissolution of metallic zinc, accompanied by a small amount of gas. Figure 5 (d) and Figure 5 (e) The negative electrode surface is shown in both charging and discharging states during cycling. By comparing the negative electrode surface in charging and discharging states, it can be seen that zinc deposition and dissolution reactions occur on the negative electrode of the alkaline nickel-zinc battery during charging and discharging, accompanied by gas evolution side reactions. It should be noted that the deposition of a large amount of zinc on the negative electrode surface can easily cause the growth of zinc dendrites, leading to short circuit problems in alkaline nickel-zinc batteries. The gas evolution side reaction mainly involves the generation of hydrogen gas on the negative electrode surface, leading to electrolyte drying and battery leakage. In addition, after charge-discharge cycle testing, when the negative electrode is in the discharge state, a small amount of zinc remains on the surface, i.e., the so-called "dead zinc" is generated on the negative electrode surface. This may be related to the loss of electrical contact between the zinc and the current collector, leading to the problem of discharge capacity decay in alkaline nickel-zinc batteries during cycling.

[0041] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A button cell device for in-situ electrochemical testing, characterized in that, include: The housing has a battery cavity formed inside it, and a transparent observation window is provided on one end face of the housing; Positive electrode plate, wherein a positive electrode observation hole is formed on the positive electrode plate; An isolation component, comprising a diaphragm layer and a transparent barrier layer, wherein the diaphragm layer has diaphragm through-holes, and the transparent barrier layer is used to cover or block the diaphragm through-holes; and A negative electrode, wherein the active material layer of the negative electrode faces the transparent observation window; The positive electrode, the isolation component, and the negative electrode are stacked sequentially in the inner cavity of the battery. The positive electrode is located on the side close to the transparent observation window, and the transparent observation window, the positive electrode observation hole, and the separator through hole overlap in the axial projection.

2. The button cell device for in-situ electrochemical testing according to claim 1, characterized in that, The transparent barrier layer is a transparent thin film layer, which is located on the upper surface and / or lower surface of the diaphragm layer, and is used to cover the diaphragm through-holes.

3. The button cell device for in-situ electrochemical testing according to claim 2, characterized in that, The transparent film layer is a transparent, alkali-resistant, and high-temperature-resistant film layer.

4. The button cell device for in-situ electrochemical testing according to claim 1, characterized in that, The transparent barrier layer is a transparent barrier block, which is inserted through the diaphragm through-hole and is used to block the diaphragm through-hole.

5. The button cell device for in-situ electrochemical testing according to claim 4, characterized in that, The transparent barrier block is a transparent, alkali-resistant, and high-temperature-resistant barrier block.

6. The button cell device for in-situ electrochemical testing according to claim 1, characterized in that, The size of the diaphragm through-hole is larger than the size of the positive electrode observation hole.

7. The button cell device for in-situ electrochemical testing according to claim 6, characterized in that, The diaphragm through-holes are circular in shape, and the diameter of the diaphragm through-holes is 1mm-3mm.

8. The button cell device for in-situ electrochemical testing according to claim 7, characterized in that, The positive electrode observation aperture has a circular structure and a diameter of 0.5mm-1mm.

9. The button cell device for in-situ electrochemical testing according to any one of claims 1-8, characterized in that, It also includes a gasket, which is located on the side of the positive electrode sheet near the transparent observation window, and the gasket has a gasket through hole. The transparent observation window, the gasket through hole, the positive electrode observation hole and the diaphragm through hole overlap in the axial projection.

10. The button cell device for in-situ electrochemical testing according to claim 9, characterized in that, It also includes a spring sheet, which is located on the side of the gasket near the transparent observation window, and the spring sheet has a spring sheet through hole. The transparent observation window, the spring sheet through hole, the gasket through hole, the positive electrode observation hole and the diaphragm through hole overlap in the axial projection.

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