In-situ optical comprehensive testing device for observable solid-liquid battery interface

Abstract

The present application relates to a kind of in-situ optical comprehensive test device of observable solid and liquid battery interface, belong to lithium battery technical field, solve the problem that lithium deposition dissolution behavior of electrode / electrolyte interface cannot be in-situ observed in existing battery technology.A kind of in-situ optical comprehensive test device of observable solid and liquid battery interface, including battery fixed table, lower sealing shell and upper sealing shell;Upper and lower sealing shell are fixedly connected by bolt;Battery fixed table is connected by screw lower sealing shell.The present application realizes the assembly and electrochemical test to solid battery and liquid battery, and correspondingly carries out in-situ optical observation to electrode interface process of different battery system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery, and particularly relates to an in-situ optical comprehensive testing device for observing solid-state and liquid-state battery interfaces. BACKGROUND

[0002] Lithium ion batteries are widely used in consumer electronics due to their superior comprehensive electrochemical performance. The properties of the interfaces between the positive and negative electrodes and the electrolyte in the battery have an important influence on the charge-discharge efficiency, energy efficiency, energy density, power density, cycle performance, service life, safety, self-discharge and other characteristics of the lithium ion battery. Interface problems are the core of the basic research of lithium ion batteries.

[0003] In recent years, the development of electric vehicles and large-scale energy storage devices has an urgent need for secondary lithium batteries with higher power density, higher energy density, longer cycle life and better safety. Solid-state batteries have attracted widespread attention at home and abroad due to their great potential in energy density and safety performance. In the research of solid-state battery technology, the interface problem between the electrode and the solid-state electrolyte is still the focus and difficulty of the research. For example, the interface impedance is large, and the volume changes. Assembling batteries with different types of electrolytes and observing the changes in the battery interface during the charge-discharge cycle process in-situ can help us deeply explore the mechanism and influencing factors of the battery interface problem in the actual process, thereby further guiding the solution of the interface problem in solid-state and liquid-state lithium batteries.

[0004] Using metal lithium with extremely high theoretical specific capacity is an important scheme to improve the energy density of lithium batteries, and is also a research hotspot in the field of lithium batteries. However, in traditional lithium ion batteries, metal lithium negative electrode is prone to lithium dendrite during the cycle process. If the lithium dendrite falls off from the surface of the battery electrode and forms "dead lithium", it will reduce the content of effective active lithium, thereby reducing the capacity of the battery. If the dendrite continues to grow on the surface of the lithium negative electrode and further penetrates the separator to contact the positive electrode, it will cause internal short circuit of the battery, and bring a series of safety problems such as fire and explosion. Solid-state electrolyte with high mechanical strength can theoretically effectively inhibit the penetration of lithium dendrite, but in fact the problem of lithium dendrite growth still exists and has not been completely solved. However, there is a lack of in-situ process and reaction mechanism research on the lithium deposition and dissolution of the electrode interface in liquid-state batteries. The research on the interface process in solid-state batteries is also very insufficient, and the mechanism of solid-state electrolyte inhibiting lithium dendrite is not clear. There is a lack of continuous real-time characterization means to observe the interface process of the electrode and the electrolyte. Therefore, there is an urgent need for a simple and effective in-situ observation device to match various in-situ testing methods and means to observe the lithium deposition and dissolution behavior of the electrode / electrolyte interface in-situ, and further study the influencing factors and reaction mechanism of the interface process. SUMMARY

[0005] In view of the above analysis, the embodiment of the present application aims to provide an in-situ optical comprehensive testing device for observing the solid-liquid battery interface, so as to solve the problem that the lithium deposition and dissolution behavior of the electrode or electrolyte interface cannot be observed in-situ in the existing lithium ion battery, and further study the influence and reaction mechanism of the interface process.

[0006] The present application is realized by the following technical solutions:

[0007] An in-situ optical comprehensive testing device for observing the solid-liquid battery interface, comprising a battery fixing table, a lower sealing shell and an upper sealing shell; the upper and lower sealing shells are fixedly connected by bolts; the battery fixing table is connected to the lower sealing shell by screws.

[0008] Further, the battery fixing table has two sides, which are the front side of the battery fixing table and the back side of the battery fixing table; the front side of the battery fixing table comprises an annular liquid groove for assembling a liquid battery; the back side of the battery fixing table is a flat surface for assembling a solid battery; a gold-plated liquid battery quartz piece is fixed at the bottom center of the annular liquid groove on the front side of the battery fixing table; a gold-plated solid battery quartz piece is fixed at the center of the back side of the battery fixing table.

[0009] Further, the two ends of the battery fixing table are respectively provided with a first circular hole and a first threaded hole penetrating through the upper and lower sides thereof; the first circular hole is used for fixing a battery negative electrode in communication with the lower sealing shell, and the first threaded hole is used for fixing a battery positive electrode in communication with the upper sealing shell.

[0010] Further, the upper sealing shell comprises a first insulating disc, a first sealing ring, a quartz piece, a second sealing ring, a first conductive disc and a third sealing ring; the first insulating disc is provided with a first observation hole in the center thereof, and the first conductive disc is provided with a second observation hole in the center thereof; the lower surface of the first insulating disc is provided with a first groove for placing the first sealing ring; the upper surface of the first conductive disc is provided with a second groove for placing the second sealing ring.

[0011] Further, the first conductive disc and the first insulating disc in the upper sealing shell are connected by bolts; the lower surface of the first conductive disc is connected to the front side of the battery fixing table, and the lower surface of the first conductive disc is provided with a third groove for placing the third sealing ring;

[0012] Further, the quartz piece is placed between the first sealing ring and the second sealing ring.

[0013] Further, the first conductive disc is made of stainless steel, and the first insulating disc is made of polytetrafluoroethylene.

[0014] Further, the lower sealing shell comprises a second insulating disc and a second conductive disc; the second insulating disc is provided with a cylindrical recess for placing the battery fixing table, the bottom surface of the cylindrical recess is in contact with the reverse surface of the battery fixing table, and the bottom surface of the cylindrical recess is provided with a second hole corresponding to the position of the first hole of the battery fixing table.

[0015] Further, the second conductive disc is connected with the second insulating disc by bolts; the second conductive disc is provided with a third threaded hole corresponding to the position of the second hole of the second insulating disc.

[0016] Further, the second conductive disc is made of stainless steel, and the second insulating disc is made of polytetrafluoroethylene.

[0017] Compared with the prior art, the battery testing device provided by the application can realize at least one of the following beneficial effects:

[0018] 1. The battery testing device provided by the application designs the front and reverse surfaces of the battery fixing table to respectively place the liquid battery and the solid battery. An annular liquid groove is designed on the front surface of the battery fixing table, so that the liquid battery assembly part is concentrated on the front surface of the battery fixing table in a skillful and simple manner. Considering the fixing property of the solid battery, the original plane is reserved on the reverse surface of the battery fixing table, so that the solid battery is concentrated on the reverse surface of the battery fixing table through the threaded hole and the fixing hole. Finally, the solid battery and the liquid battery can be respectively fixed on the battery fixing table, the function of "one device with two uses" is realized, and the comprehensive testing device supporting in-situ optical observation of the electrode interface of the solid battery (especially for the gel electrolyte type) and the liquid battery is provided.

[0019] 2. The battery fixing table provided by the application enables the solid battery and the liquid battery to be fixed and electrically contacted with the upper and lower sealing shells through screws, simplifies various wire connections, makes the overall installation of the device simpler, and realizes stable and reliable connection.

[0020] 3. In the application, the first insulating disc and the first conductive disc in the upper sealing shell are made of stainless steel or polytetrafluoroethylene, and have poor light transmission. In order to ensure the permeability of the whole observation light path, a first observation port and a second observation port are arranged on the upper sealing shell to observe the charging and discharging behavior of the liquid battery. A simple plane is arranged on the reverse surface of the battery fixing table and in the lower sealing shell to observe the charging and discharging behavior of the solid battery, so that in-situ optical imaging of the battery interface in the charging and discharging cycle of the solid battery and the liquid battery is realized, and the application can be applied to various optical instruments, such as optical microscopes, infrareds and Raman spectrometers, and has a wide application range. The overall structure of the application is simple, the installation is convenient, the sealing property is good, the safety and stability are good, and thus the application can be widely applied to the observation and testing of the solid battery and the liquid battery.

[0021] 4. In this application, a first and a second sealing ring are provided in the upper sealed shell to ensure the sealing of the quartz plate; at the same time, a third sealing ring is provided on the lower surface of the first conductive disc of the upper sealed shell to ensure the sealing between the upper sealed shell and the lower sealed shell, to ensure that the battery reaction is carried out in a completely sealed state, and to ensure the accuracy of the experimental results.

[0022] 5. In addition to providing multiple sealing rings to ensure the airtightness of the device, the present invention also features threaded holes in the upper and lower sealed housings that are arranged and distributed in a manner corresponding to the fixing holes. For example, the first conductive disc is provided with a third fixing hole and a second threaded hole corresponding to the first and second fixing holes. The first insulating disc and the first conductive disc are fixedly connected by bolts passing through the second fixing hole and the second threaded hole. The second insulating disc is provided with a fourth fixing hole and a fifth fixing hole spaced apart from each other. The second conductive disc is provided with a fourth threaded hole and a fifth threaded hole corresponding to the fourth and fifth fixing holes. The second insulating disc and the second conductive disc are fixedly connected by bolts passing through the fifth fixing hole and the fifth threaded hole. This arrangement fully ensures airtightness throughout the assembly of the device.

[0023] 6. A gold-plated quartz sheet is fixed to the center of the front and back sides of the fixing platform of the present invention with double-sided tape to reflect light and improve the brightness and clarity of the optical imaging field of view.

[0024] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0026] Figure 1 A front view schematic diagram of the battery fixing platform structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the reverse side of the battery fixing platform structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the sealing shell structure of the present invention;

[0029] Figure 4 This is a schematic diagram of the lower sealed housing structure of the present invention;

[0030] Figure 5The schematic diagram of assembling the liquid battery of the present application;

[0031] Figure 6 The schematic diagram of assembling the solid battery of the present application;

[0032] Figure 7 The optical imaging diagram of lithium dendrite growth of the solid battery of the present application.

[0033] Reference signs:

[0034] 11 - the front of the battery fixing platform; 12 - the back of the battery fixing platform; 13 - the annular liquid tank; 14 - the first circular hole; 15 - the first threaded hole; 21 - the first insulating disc; 22 - the first sealing ring; 23 - the quartz sheet; 24 - the second sealing ring; 25 - the first conductive disc; 26 - the third sealing ring; 211 - the first fixing hole; 212 - the second fixing hole; 213 - the first observation port; 214 - the first groove; 251 - the third fixing hole; 252 - the second threaded hole; 253 - the second observation port; 254 - the second groove; 255 - the third groove; 31 - the second insulating disc; 32 - the second conductive disc; 311 - the fourth fixing hole; 312 - the fifth fixing hole; 313 - the cylindrical groove; 314 - the second circular hole; 321 - the fourth threaded hole; 322 - the fifth threaded hole; 323 - the third threaded hole; 41 - the negative electrode sheet of the liquid battery; 42 - the positive electrode sheet of the liquid battery; 43 - the quartz sheet of the liquid battery; 44 - the negative electrode sheet of the solid battery; 45 - the positive electrode sheet of the solid battery; 46 - the quartz sheet of the solid battery. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present application will be described in detail below with reference to the drawings, which form a part of this application, and together with the embodiments of the present application serve to explain the principles of the present application, and are not intended to limit the scope of the present application.

[0036] The present application provides a kind of in-situ optical observation solid or liquid battery interface comprehensive test device of simple operation, easy to assemble for the above problems, as shown in Figures 1-6 The technical scheme adopted by the present application is as follows: a kind of in-situ optical comprehensive test device for observing solid and liquid battery interface, including battery fixing platform, upper sealing shell and lower sealing shell; the upper and lower sealing shell is fixedly connected by bolt, and the battery fixing platform is fixed by screwing the upper sealing shell and the lower sealing shell; the battery fixing platform is the core component for assembling battery (including positive and negative electrode and electrolyte), and the negative electrode part of the battery is communicated with the lower sealing shell, and the positive electrode part is communicated with the upper sealing shell. The present application can realize the assembly and electrochemical test of solid battery and liquid battery respectively by changing the placement mode of the upper sealing shell and the lower sealing shell, and the in-situ optical observation of electrode interface process of different battery systems is correspondingly carried out.

[0037] The battery fixing platform is made of polytetrafluoroethylene material, such as Figure 1 As shown in Figure 2 The battery fixing platform includes a front surface 11 and a back surface 12. The front surface 11 contains a ring-shaped liquid tank 13 for assembling liquid batteries and observing and testing the interface of the liquid batteries. The back surface 12 is a flat surface without a ring-shaped liquid tank, which is used for assembling solid-state batteries and observing and testing the interface of the solid-state batteries. The electrolyte of the solid-state battery includes organic electrolyte, inorganic electrolyte, and inorganic-organic composite electrolyte. The battery fixing platform is provided with a first circular hole 14 and a first threaded hole 15 at both ends of the battery fixing platform, which penetrate the front surface 11 and the back surface 12. The first circular hole 14 is used to fix the negative electrode of the battery connected to the lower sealing shell, and the first threaded hole 15 is used to fix the positive electrode of the battery connected to the upper sealing shell.

[0038] The upper sealing shell includes a first insulating disc 21, a first sealing ring 22, a quartz sheet 23, a second sealing ring 24, a first conductive disc 25, and a third sealing ring 26. The first insulating disc 21 is provided with a first observation port 213 in the center, and the lower surface of the first insulating disc 21 is provided with a first groove 214 in the center for placing the first sealing ring 22 and the second sealing ring 24.

[0039] The first conductive disc 25 is connected to the first insulating disc 21 by a bolt. The first conductive disc 25 is provided with a second observation port 253 in the center, and the lower surface of the first conductive disc is in contact with the upper surface of the battery fixing platform. The upper surface of the first conductive disc is provided with a groove for placing the first sealing ring 22 and the second sealing ring 24. The lower surface of the first conductive disc is provided with a second groove 254 for placing the third sealing ring. The quartz sheet 23 is arranged between the first observation port 213 and the second observation port 253 of the first insulating disc and the first conductive disc. The first sealing ring 22 is arranged on the upper surface of the quartz sheet 23, and the second sealing ring 24 is arranged on the lower surface of the quartz sheet. The third sealing ring 26 is arranged at the contact position of the first conductive disc 25 and the second insulating disc 31.

[0040] The first conductive disc is made of stainless steel, and the first insulating disc is made of polytetrafluoroethylene material.

[0041] The lower sealing shell includes a second insulating disc 31 and a second conductive disc 32. The second insulating disc 31 is provided with a cylindrical groove 313 for placing the battery fixing platform. The bottom surface of the cylindrical groove is in contact with the back surface of the battery fixing platform. The bottom surface of the cylindrical groove 313 is provided with a second circular hole 314 corresponding to the position of the first circular hole of the battery fixing platform. The second conductive disc 32 is connected to the second insulating disc 31 by a bolt, and the second conductive disc is provided with a third threaded hole 323 corresponding to the position of the second circular hole 314 of the second insulating disc.

[0042] The second conductive disc is made of stainless steel, and the second insulating disc is made of polytetrafluoroethylene.

[0043] The application provides a kind of in situ optical observation solid, liquid battery interface comprehensive testing device, including battery fixed platform, upper sealing shell and lower sealing shell, upper and lower sealing shell are fixedly connected by bolt, battery fixed platform and lower sealing shell are fixedly connected by bolt.Battery fixed platform is used to assemble and fix battery structure, and the positive part of solid battery is communicated with upper sealing shell, and the negative part of solid battery is communicated with lower sealing shell.

[0044] As shown in Figure 1 Battery fixed platform is an insulating cylinder, including battery fixed platform front 11 and battery fixed platform back 12.Battery fixed platform front 11 is used to observe and measure liquid battery, including a ring liquid tank 13, for containing liquid electrolyte;Battery fixed platform back 12 is a plane, without ring liquid tank, for assembling and placing gel electrolyte solid battery, gel electrolyte before curing is quantitatively dropped in the center position of battery fixed platform back 12;Ring liquid tank 13 is provided with a first circular hole 14 and a first threaded hole 15 near both ends of the ring liquid tank 13, the first circular hole 14 is used to fix the battery negative electrode (including liquid battery and solid battery) communicated with lower sealing shell, and the first threaded hole 15 is used to fix the battery positive electrode (including liquid battery and solid battery) communicated with upper sealing shell.

[0045] As shown in Figure 3 Upper sealing shell includes first insulating disc 21 and first conductive disc 25, quartz sheet 23, first sealing ring 22, second sealing ring 24 and third sealing ring 26.First insulating disc 21 is provided with first observation port 213 in the center, and the lower surface of first conductive disc 25 is provided with first recess 214 for placing small sealing ring;First conductive disc 25 is connected with first insulating disc 21 by bolt, and first conductive disc 25 is provided with second observation port 253 in the center, and the upper surface of first conductive disc 25 is provided with recess for placing second sealing ring 24, and the lower surface of first conductive disc 25 is provided with third recess 255 for placing third sealing ring 26;Quartz sheet 23 is arranged between first observation port 213 and second 253 of first insulating disc 21 and first conductive disc 25;First sealing ring 22 is arranged in first recess 214 of the lower surface of first insulating disc 21, and second sealing ring 24 is arranged in second recess 254 of the upper surface of first conductive disc 25;Third sealing ring 26 is arranged in third recess 255 of the lower surface of first conductive disc 25, and contacts with second insulating disc 31 below.

[0046] As shown in Figure 4As shown, the lower sealing shell comprises a second insulating disc 31 and a second conductive disc 32. The second insulating disc 31 is provided with a cylindrical recess 313 in the center for placing the battery fixing platform, the bottom of the cylindrical recess 313 is in contact with the reverse surface 12 of the battery fixing platform, and the second insulating disc 31 is provided with a second hole 314 near the center in the cylindrical recess 313, which corresponds to the position of the first hole 14 of the battery fixing platform. The second conductive disc 32 is bolted with the second insulating disc 31, and the second conductive disc 32 is provided with a third threaded hole 323 corresponding to the first hole 14 and the second hole 314.

[0047] In the above embodiments, the battery fixing platform is made of polytetrafluoroethylene material, the first insulating disc 21 is made of polytetrafluoroethylene material, the first conductive disc 25 is made of stainless steel material, the second insulating disc 31 is made of polytetrafluoroethylene material, and the second conductive disc 32 is made of stainless steel material.

[0048] In the above embodiments, the first insulating disc 21 is provided with a first fixing hole 211 and a second fixing hole 212 at intervals, the first conductive disc 25 is provided with a third fixing hole 251 and a second threaded hole 252 corresponding to the positions of the first fixing hole 211 and the second fixing hole 212, and the first insulating disc 21 and the first conductive disc 25 are fixedly connected by bolts passing through the second fixing hole 212 and the second threaded hole 252.

[0049] In the above embodiments, the second insulating disc 31 is provided with a fourth fixing hole 311 and a fifth fixing hole 312 at intervals, the second conductive disc 32 is provided with a fourth threaded hole 321 and a fifth threaded hole 322 corresponding to the positions of the fourth fixing hole 311 and the fifth fixing hole 312, and the second insulating disc 31 and the second conductive disc 32 are fixedly connected by bolts passing through the fifth fixing hole 312 and the fifth threaded hole 322.

[0050] In order to improve the brightness of the optical imaging field of view, the quartz sheet is arranged on the battery fixing platform, as shown in Figure 5 As shown, the liquid battery adopts the front surface 11 of the battery fixing platform, and a gold-plated liquid battery quartz sheet 43 is fixed on the central annular liquid tank 13 of the front surface 11 of the battery fixing platform by double-sided tape. Figure 6 As shown in the middle, the solid-state battery adopts the reverse surface 12 of the battery fixing platform, and the reverse surface 12 of the battery fixing platform is placed in the cylindrical recess 313 in the center of the second insulating disc 31. A gold-plated solid-state battery quartz sheet 46 is fixed on the central part of the reverse surface 12 of the battery fixing platform by double-sided tape.

[0051] To ensure the battery's insulation, one end of the liquid battery negative electrode sheet 41 is secured to the battery mounting base near the first circular hole 14 with double-sided tape. A small piece of the negative electrode current collector is cut and placed over this end of the liquid battery negative electrode sheet 41. One end of the liquid battery positive electrode sheet 42 is secured to the battery mounting base's threaded hole 15 with double-sided tape. One end of the solid-state battery negative electrode sheet 44 is secured to the battery mounting base near the first circular hole 14 with double-sided tape. A small piece of the negative electrode current collector is cut and placed over this end of the negative electrode sheet. The other end of the solid-state battery positive electrode sheet 45 is extended to near the center of the back surface, facing the solid-state battery negative electrode sheet 44 but leaving a certain distance.

[0052] The working principle of the present invention is as follows: Regarding the working principle of liquid batteries, Figure 5 As shown, the battery holder is placed with its front face 11 facing upward within the cylindrical recess 313 in the center of the second insulating disc 31. A gold-plated liquid battery quartz plate 43 is attached to the center of the bottom of the annular liquid tank 13 on the front face 11 of the battery holder using double-sided tape to improve the brightness of the optical imaging field of view. The battery is then assembled. One end of the liquid battery negative electrode sheet 41 is fixed near the first circular hole 14 of the battery fixing table with double-sided tape. A small piece of negative electrode current collector is cut and covered on this end of the liquid battery negative electrode sheet 41. A long screw is passed through the negative electrode current collector, the first circular hole 14, the second circular hole 314 and the third threaded hole 323 in sequence to fix the battery fixing table to the lower sealed shell, and the entire negative electrode part of the battery is fixed and connected to the second conductive disc 32. In order to prevent the negative electrode part of the battery from contacting the first conductive disc 25 during the assembly of the entire device, a small piece of double-sided tape needs to be covered on the long screw nut to ensure that the negative electrode part is completely insulated from the first conductive disc 25. The other end of the negative electrode sheet is bent and placed in the annular liquid tank 13. Secure one end of the liquid battery positive electrode sheet 42 to the threaded hole 15 of the battery mounting platform using double-sided tape. Cut a small piece of the positive electrode current collector and place it over the negative electrode sheet. Use a short screw to pass through the positive electrode current collector and the first threaded hole 15, securing the positive portion of the battery to the battery mounting platform. Bend the other end of the liquid battery positive electrode sheet 42 and place it within the annular liquid tank 13, facing the liquid battery negative electrode sheet 41 but leaving a certain distance. The two opposing positive and negative electrode sheets within the annular liquid tank 13 are aligned with the first observation ports 213 and first observation ports 253 of the first insulating disc 21 and first conductive disc 25 of the sealed housing, ensuring that the interfaces between the positive and negative electrodes and the electrolyte can be observed with an optical microscope. An appropriate amount of electrolyte is dripped into the annular liquid tank 13, ensuring that the amount of electrolyte is sufficient to submerge the opposing positive and negative electrode portions within the annular liquid tank 13.

[0053] The working principle of solid-state batteries is roughly the same as that of liquid batteries, but there are also some differences in details. Figure 6As shown in the middle, the solid-state battery uses the battery fixing platform reverse surface 12, which is placed upside down in the cylindrical recess 313 in the center of the second insulating disc 31. A gold-plated solid-state battery quartz sheet 46 is fixed to the center of the battery fixing platform reverse surface 12 with double-sided tape to improve the brightness of the optical imaging field of view. Then, the battery is assembled, one end of the solid-state battery negative electrode sheet 44 is fixed near the first circular hole 14 of the battery fixing platform with double-sided tape, a small piece of negative electrode current collector is cut and placed on the end of the negative electrode sheet, a long screw is used to pass through the negative electrode current collector, the first circular hole 14, the second circular hole 314, and the third threaded hole 323 in sequence, the battery fixing platform is fixed to the lower sealing shell, and the entire negative electrode part of the battery is fixed and connected to the second conductive disc 32; and to prevent the negative electrode part of the battery from contacting the first conductive disc 25 during the assembly of the entire device, a small piece of double-sided tape is covered on the nut of the long screw to ensure that the negative electrode part is completely insulated from the first conductive disc 25; the other end of the solid-state battery negative electrode sheet 44 extends to the vicinity of the center of the reverse surface. One end of the solid-state battery positive electrode sheet 45 is fixed near the first threaded hole 15 of the battery fixing platform with double-sided tape, a small piece of positive electrode current collector is cut and placed on the end of the negative electrode sheet, a short screw is used to pass through the positive electrode current collector and the first threaded hole 15 in sequence, the positive electrode part of the battery is fixed to the battery fixing platform, and the other end of the solid-state battery positive electrode sheet 45 extends to the vicinity of the center of the reverse surface, opposite to the solid-state battery negative electrode sheet 44 but leaving a certain distance. The two opposite positive and negative electrode sheets in the annular liquid tank 13 are opposite to the first observation port 213 and the second observation port 253 of the first insulating disc 21 and the first conductive disc 25 in the upper sealing shell, ensuring that the optical microscope can observe the positive and negative electrode and electrolyte interface. The amount of gel electrolyte is appropriately added to the center of the reverse surface before curing, and the amount of gel electrolyte is sufficient to soak the positive and negative electrode parts near the center of the reverse surface.

[0054] The assembly of the upper sealing shell is carried out, that is, the first insulating disc 21, the sealing ring 22, the quartz sheet 23, the sealing ring 24, the first conductive disc 25, and the third sealing ring 26 are assembled in sequence, and the second fixing hole 212 and the second threaded hole 252 are aligned and fixed together by a screw.

[0055] The assembly of the lower sealing shell is carried out, that is, the second insulating disc 31 and the second conductive disc 32 are fixed together through the fifth fixing hole 312 and the fifth threaded hole 322.

[0056] The assembled liquid or solid-state battery is fixed to the second conductive disc 32 in the lower sealing shell by a screw passing through the first circular hole 14 on the battery fixing platform, the second circular hole 314 in the cylindrical recess of the second insulating disc 31, and the third threaded hole 323 on the second conductive disc 32, and the negative electrode part of the liquid or solid-state battery makes electrical contact with the second conductive disc 32 in the lower sealing shell.

[0057] The third sealing ring 26 is placed in the third groove 255 of the first conductive disc 25 in the upper sealing shell, and then the upper sealing shell is covered and fixed by screws through the first fixing hole 211 of the first insulating disc 21, the third fixing hole 251 of the first conductive disc 25, the fourth fixing hole 311 of the second insulating disc 31 and the fourth threaded hole 321 of the second conductive disc 32 in sequence. When the sealing ring 26 is compressed, the positive electrode of the liquid or solid battery contacts the first conductive disc 25 in the upper sealing shell through the screw inserted into the first threaded hole 15 of the battery fixing table.

[0058] The wires connected to the positive and negative electrodes are respectively connected to the first conductive disc 25 and the second conductive disc 32, so that a series of electrochemical tests can be performed on the liquid or solid battery. While performing the electrochemical test, the device is placed under the lens of an optical microscope, and the first observation port 213 and the second observation port 253 of the upper sealing shell and the transparent quartz sheet 23 are used to realize in-situ observation of the electrode / electrolyte interface of the liquid or solid battery, so that the in-situ process of lithium deposition and dissolution at the negative electrode / electrolyte interface in the liquid or solid battery is obtained. As shown in the accompanying drawings, in the battery interface reaction of the solid battery, lithium is deposited on the surface of the copper sheet, and lithium dendrites are generated when the lithium deposition reaches a certain degree. Figure 7

[0059] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical range disclosed by the present application can be easily thought by those skilled in the art, and should be covered in the protection scope of the present application.​

Claims

1. An in-situ optical comprehensive testing device for observable solid-liquid battery interface, characterized in that, The battery fixing platform, the lower sealing shell and the upper sealing shell are connected by bolts; the battery fixing platform is connected with the lower sealing shell by screws; The battery fixing platform has two surfaces, i.e., a front surface and a back surface; the front surface has a ring-shaped liquid tank for containing liquid electrolyte to assemble a liquid battery; the back surface is a flat surface for assembling a solid battery; The battery fixing platform has a first circular hole and a first threaded hole at each end of the battery fixing platform; the first circular hole and the first threaded hole are arranged at the two ends of the ring-shaped liquid tank, and the first circular hole is used to fix a negative electrode of the battery connected with the lower sealing shell, and the first threaded hole is used to fix a positive electrode of the battery connected with the upper sealing shell; When the liquid battery is tested, the front surface of the battery fixing platform is placed upward in the lower sealing shell; one end of the negative electrode of the liquid battery is fixed near the first circular hole by double-sided tape, the current collector of the negative electrode is covered on the one end of the negative electrode of the liquid battery, a long screw is sequentially passed through the current collector of the negative electrode and the first circular hole to fix the battery fixing platform on the lower sealing shell, and the other end is placed in the ring-shaped liquid tank after being bent; one end of the positive electrode of the liquid battery is fixed near the first threaded hole by double-sided tape, the current collector of the positive electrode is covered on the one end of the positive electrode of the liquid battery, a short screw is sequentially passed through the current collector of the positive electrode and the first threaded hole to fix the positive electrode of the battery on the battery fixing platform, and the other end is placed in the ring-shaped liquid tank after being bent, and the positive electrode and the negative electrode are placed opposite to each other with a distance. When the solid battery is tested, the back surface of the battery fixing platform is placed upward in the lower sealing shell; one end of the negative electrode of the solid battery is fixed near the first circular hole by double-sided tape, the current collector of the negative electrode is covered on the one end of the negative electrode of the solid battery, a long screw is sequentially passed through the current collector of the negative electrode and the first circular hole to fix the battery fixing platform on the lower sealing shell, and the other end extends to the center of the back surface of the battery fixing platform; one end of the positive electrode of the solid battery is fixed near the first threaded hole by double-sided tape, the current collector of the positive electrode is covered on the one end of the positive electrode of the solid battery, a short screw is sequentially passed through the current collector of the positive electrode and the first threaded hole to fix the positive electrode of the battery on the battery fixing platform, and the other end extends to the center of the back surface of the battery fixing platform, and is opposite to the negative electrode with a distance; the gel electrolyte of the solid battery is dropped in the center of the back surface of the battery fixing platform, and the amount of the gel electrolyte can soak the positive electrode and the negative electrode near the center of the back surface of the battery fixing platform.

2. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 1, characterized in that, A liquid battery quartz piece plated with gold on the surface is fixed at the center of the bottom of the ring-shaped liquid tank of the front surface of the battery fixing platform; a solid battery quartz piece plated with gold on the surface is fixed at the center of the back surface of the battery fixing platform.

3. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 1, characterized in that, The upper sealed shell includes a first insulating disc, a first sealing ring, a quartz plate, a second sealing ring, a first conductive disc and a third sealing ring; a first observation port is provided in the center of the first insulating disc, and a second observation port is provided in the center of the first conductive disc; a first groove for placing the first sealing ring is provided in the center of the lower surface of the first insulating disc; a second groove for placing the second sealing ring is provided on the upper surface of the first conductive disc.

4. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 3, characterized in that, The first conductive disc and the first insulating disc in the upper sealed shell are connected with bolts; the lower surface of the first conductive disc is connected to the front of the battery fixing platform, and the lower surface of the first conductive disc is provided with a third groove for accommodating a third sealing ring.

5. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 4, characterized in that, The quartz plate is placed between the first sealing ring and the second sealing ring.

6. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 5, characterized in that, The first conductive disc is made of stainless steel, and the first insulating disc is made of polytetrafluoroethylene.

7. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 1, characterized in that, The lower sealed shell includes a second insulating disc and a second conductive disc; the second insulating disc is provided with a cylindrical groove for placing the battery fixing platform, the bottom surface of the cylindrical groove is in contact with the back surface of the battery fixing platform, and the bottom surface of the cylindrical groove is provided with a second circular hole corresponding to the position of the first circular hole of the battery fixing platform.

8. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 7, characterized in that, The second conductive disc is connected to the second insulating disc by means of bolts; the second conductive disc is provided with a third threaded hole corresponding to the position of the second circular hole of the second insulating disc.

9. The in-situ optical comprehensive testing device of observable solid-liquid and liquid-liquid battery interface according to claim 8, characterized in that, The second conductive disc is made of stainless steel, and the second insulating disc is made of polytetrafluoroethylene.

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