Multifunctional battery electrochemical testing device

Abstract

The utility model discloses a multifunctional battery electrochemical testing device. The multifunctional battery electrochemical testing device comprises a detection box, a clamping unit, a driving unit and a detection unit, the detection box comprises a shell and a cover plate, a cavity is formed in the shell, and the side wall is provided with a vacuum cable connector; the surface of the cover plate is provided with an opening and slidably connected with a movable baffle. The driving unit, the clamping unit and the detection unit are installed in the cavity, the opening directly faces the clamping unit, the movable baffle slides and shields the opening, the cavity enters a closed state, the cavity can be vacuumized through the vacuum cable connector, so that the cavity and the to-be-detected battery are in a vacuum environment, and pressure difference is formed inside and outside the cavity. According to the utility model, the baffle plate is moved to shield the opening, so that the cavity forms a closed space; the vacuum cable connector is connected with external equipment to vacuumize the detection box, and the to-be-detected battery is in a vacuum environment, so that the to-be-detected battery is prevented from being polluted by external impurities in a transfer process, vacuum transfer of the to-be-detected battery is realized, and the test accuracy is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of precision instruments, especially a kind of multifunctional battery electrochemistry testing device. BACKGROUND

[0002] With the desire for real-time, dynamic observation of the electrochemical reaction in electrode materials, people realize the importance of deeply understanding the correlation between material microstructure evolution and performance. Various in-situ characterization methods are applied in the field of lithium-ion batteries. In-situ spectroscopy methods (such as X-ray diffraction, neutron diffraction, X-ray absorption spectroscopy, etc.) can only obtain average information of structural evolution, atomic occupation and electron distribution. Compared with them, electron microscopy has the advantage of "seeing is believing". However, due to the high resolution of transmission electron microscopy and the limitation of sample size, in-situ transmission electron microscopy method can only observe the reaction mechanism of single particle level, and cannot fully understand the electrochemical-mechanical coupling mechanism of electrode materials in actual bulk batteries. Compared with transmission electron microscopy, scanning electron microscopy has moderate resolution and larger sample chamber space, which provides sufficient conditions for the study of actual bulk batteries. By combining scanning electron microscopy with electrochemical test equipment, the morphology change and element distribution of electrode materials can be obtained during the charging and discharging process of the battery. However, during the installation and transfer of the battery to the scanning electron microscope before testing, how to avoid the pollution of the battery by external impurities becomes a problem to be solved. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the utility model provides a kind of multifunctional battery electrochemistry testing device, adopt a new type of differential pressure opening and closing scheme without drive, can be realized in atmospheric pressure long time vacuum closure to the battery to be measured, and the vacuum transfer is carried out to the battery to be measured, to avoid the pollution of the battery to be measured by external impurities.

[0004] The utility model solves the technical scheme that the technical scheme that the utility model solves its technical problem is as follows: a kind of multifunctional battery electrochemistry testing device, comprising:

[0005] Detection box, including shell, and with the detachable connection of shell cover, the shell inside forms cavity, shell side wall has the vacuum cable connector for communicating inside and outside cavity;The surface of the cover has an opening, and the cover is slidably connected with a movable baffle for shielding or opening the opening;

[0006] Clamping unit is used to clamp the battery to be measured;

[0007] Drive unit is used to control the output pressure load to the battery to be measured;

[0008] Detection unit is used for comprehensive testing of the battery to be measured;

[0009] The drive unit, clamping unit, and detection unit are installed inside the cavity. The opening is directly opposite the clamping unit. The movable baffle slides and blocks the opening, and the cavity enters a closed state. A vacuum can be drawn through the vacuum cable connector so that the cavity and the battery under test are in a vacuum environment, and a pressure difference is formed inside and outside the cavity.

[0010] This invention uses a movable baffle to block the opening, creating a closed space within the cavity to prevent the battery under test from contacting the outside environment. An external device is connected via a vacuum cable connector to perform a vacuuming operation on the testing chamber, ensuring the cavity reaches a vacuum state. The battery under test remains in a vacuum environment, preventing contamination from oxygen, moisture, or dust in the air or other gaseous environments during transfer, thus achieving vacuum transfer and ensuring testing accuracy. Furthermore, the clamping unit, driving unit, and testing unit provide comprehensive testing of the battery under test, offering diverse functions.

[0011] Furthermore, an elastic element is connected to the surface of the cover plate. This elastic element includes a fixed base, a fixed support, and a tension spring. The fixed base is fixedly connected to the cover plate. One end of the fixed support is fixedly connected to the fixed base, and the other end is connected to the tension spring. The other end of the tension spring is connected to a movable baffle, which pushes the movable baffle to slide towards the opening, causing the tension spring to deform and stretch. Both the movable baffle and the cover plate are provided with positioning holes, allowing screws to be used to connect the movable baffle and the cover plate to fix the sliding position of the movable baffle. By sliding the movable baffle, the opening on the surface of the cover plate is covered, achieving a seal of the internal environment of the detection chamber. The elastic element rebounds, causing the movable baffle to automatically reset, making operation simple.

[0012] Furthermore, both the outer shell and the cover plate have sealing grooves on their surfaces for placing O-rings. The outer shell sidewall also has a liquid nitrogen transfer flange, which is connected to the detection unit to transfer liquid nitrogen to the detection unit. The O-rings ensure a tight connection between the cover plate and the outer shell, guaranteeing a completely closed and sealed space inside the detection chamber, preventing impurities in the air from entering.

[0013] Furthermore, the cover plate is connected to a positioning baffle, which has a guide groove. The movable baffle has a positioning post on its surface, which extends out of the guide groove and can slide along the guide groove. Applying an external force pushes the positioning post to move in the direction of the opening, thereby driving the movable baffle to move. The guide groove can restrict the positioning post to move linearly along the guide groove, and the abutment between the movable baffle and the cover plate can limit the movement distance of the movable baffle, so that the tension spring can be used within the allowable tension length range, avoiding failure due to excessive tension distance.

[0014] Furthermore, a base is installed inside the cavity, and the drive unit, clamping unit, and detection unit are sequentially mounted on the base. The clamping unit includes a U-shaped insulating base, an electrochemical clamp positive electrode, an electrochemical clamp negative electrode, and a ceramic screw connecting the electrochemical clamp positive and negative electrodes. The surface of the electrochemical clamp negative electrode has a hexagonal countersunk hole for mounting the ceramic screw. The base allows for separate installation of the detection equipment and the detection box, facilitating timely replacement of damaged parts and extending service life.

[0015] Furthermore, the drive unit includes an eight-bar displacement amplification flexible hinge and a piezoelectric ceramic actuator. The piezoelectric ceramic actuator is cylindrical, with a socket and a boss at each end. One end of the piezoelectric ceramic actuator is threadedly connected to the eight-bar displacement amplification flexible hinge through the socket, and the other end is fastened to the eight-bar displacement amplification flexible hinge with a fastener.

[0016] Furthermore, the detection unit includes a heating component, a cooling component, a temperature measuring component, and a force detection component. The heating component includes a heating fixing plate, an insulating pressure head A fixedly connected to the heating fixing plate, and a resistance heater. The heating fixing plate has a through hole, and the resistance heater is disposed in the through hole. The top of the insulating pressure head A has a countersunk hole for installing the temperature measuring component.

[0017] Furthermore, the refrigeration assembly includes a liquid nitrogen refrigeration plate and an insulating pressure head B fixedly connected to the liquid nitrogen refrigeration plate. The liquid nitrogen refrigeration plate is internally permeable and has transmission pipes for transmitting liquid nitrogen and countersunk holes on both sides.

[0018] Furthermore, the temperature measuring component includes two platinum resistance thermometers, which are cylindrical and respectively placed in the countersunk holes of the insulating pressure head A and the liquid nitrogen cooling plate.

[0019] Furthermore, the force detection component includes a pressure sensor, a connecting rod, and a guide seat. One end of the connecting rod is connected to the insulating pressure head B, and the other end is connected to the pressure sensor. The end of the pressure sensor is cylindrical and passes through the guide seat, which is connected to the force-bearing base.

[0020] The beneficial effects of this utility model are: 1) It adopts a new differential pressure opening and closing scheme, which connects to external equipment through a vacuum cable connector to evacuate the inside of the test chamber, so that a vacuum cavity is formed inside the test chamber. Under the action of the pressure difference between the inside and outside of the test chamber, the test chamber is vacuum closed for a long time under atmospheric pressure to transfer the battery under test in a vacuum, avoiding contamination of the battery under test by oxygen, moisture or dust in the gaseous environment of air and other media during the transfer process; 2) It adopts a new non-drive method. Under the pulling force of the elastic element, the moving baffle automatically resets to expose the battery under test, which is convenient for observation of the battery under test; 3) The clamping unit, driving unit and detection unit are all placed in the test chamber, which integrates pressure, heating and cooling tests into one unit, and also has multiple electrochemical testing methods, making it versatile; 4) The test chamber has a compact structure, small size and light weight, and can be used in conjunction with scanning electron microscopes and vacuum glove boxes of various brands. The shape and size of the battery under test can vary within a certain range, making it highly practical. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the battery electrochemical testing device of this utility model. Figure 1 .

[0022] Figure 2 This is a three-dimensional structural diagram of the battery electrochemical testing device of this utility model. Figure 2 .

[0023] Figure 3 This is a top view of the battery electrochemical testing device of this utility model.

[0024] Figure 4 This is a partial three-dimensional structural diagram of the battery electrochemical testing device of this utility model. Figure 1 .

[0025] Figure 5 This is a partial three-dimensional structural diagram of the battery electrochemical testing device of this utility model. Figure 2 .

[0026] Figure 6 This is a three-dimensional structural diagram of the detection box and base in this utility model.

[0027] Figure 7 This is a cross-sectional view of the testing box in this utility model.

[0028] Figure 8 This is a three-dimensional structural diagram of the base in this utility model.

[0029] Figure 9 This is a three-dimensional structural diagram of the clamping unit in this utility model.

[0030] Figure 10This is a top view of the clamping unit in this utility model.

[0031] Figure 11 This is a front view of the clamping unit in this utility model.

[0032] Figure 12 This is a three-dimensional structural diagram of the driving unit in this utility model.

[0033] Figure 13 This is a three-dimensional structural diagram of the medium-voltage ceramic actuator of this utility model.

[0034] Figure 14 This is a cross-sectional view of the drive unit in this utility model.

[0035] Figure 15 This is a schematic diagram illustrating the working principle of the drive unit in this utility model.

[0036] Figure 16 This is a three-dimensional structural diagram of the heating component and temperature measuring component after assembly in this utility model.

[0037] Figure 17 This is a top view of the heating component and temperature measuring component assembled in this utility model.

[0038] Figure 18 This is a three-dimensional structural diagram of the refrigeration component and the temperature measuring component after assembly in this utility model.

[0039] Figure 19 This is a cross-sectional view of the refrigeration component and the temperature measuring component after assembly in this utility model.

[0040] Figure 20 This is a three-dimensional structural diagram of the force detection component in this utility model.

[0041] Figure 21 This is a top view of the force detection component in this utility model.

[0042] Figure 22 This is a cross-sectional view of the force detection component in this utility model.

[0043] Among them, 1-detection box, 11-outer shell, 111-cavity, 112-liquid nitrogen transfer flange, 113-vacuum cable connector, 114-sealing groove, 12-cover plate, 121-opening, 122-slide groove, 13-base, 131-base plate, 132-clamping plate, 15-elastic element, 151-fixed seat, 152-fixed support column, 153-tension spring, 16-moving baffle, 161-positioning column, 1611-neck, 1612-protrusion, 162-positioning hole, 17-positioning baffle, 171-guide groove, 2-clamping unit, 21-insulating base, 22-positive electrode of electrochemical clamp. 23-Electrochemical clamp negative electrode, 24-Ceramic screw, 25-Hexagonal countersunk hole, 3-Drive unit, 31-Eight-bar displacement amplification flexible hinge, 32-Piezoelectric ceramic actuator, 321-Socket, 322-Boss, 4-Heating assembly, 41-Heating fixing plate, 411-Through hole, 42-Insulating pressure head A, 421-Round countersunk hole, 43-Resistance heater, 5-Refrigeration assembly, 51-Liquid nitrogen cooling plate, 52-Insulating pressure head B, 53-Transmission tube, 6-Temperature measuring assembly, 61-Platinum resistance thermometer, 7-Force detection assembly, 71-Pressure sensor, 72-Connecting rod, 73-Guide seat, 8-Battery under test. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0045] A multifunctional battery electrochemical testing device includes a detection box 1, a clamping unit 2, a driving unit 3, and a detection unit. Figures 1-7 As shown, the detection box 1 includes an outer shell 11 and a cover plate 12 detachably connected to the outer shell 11. The cover plate 12 can be detachably installed to the outer shell 11 using screws, allowing other parts to be placed inside the outer shell 11. A cavity 111 is formed inside the outer shell 11. A vacuum cable connector 113 is installed on one side wall of the outer shell 11 to connect the inside and outside of the cavity 111, and a liquid nitrogen transfer flange 112 is installed on the other side wall. Specifically, in this embodiment, there are three vacuum cable connectors 113, which can be connected to external devices via cables to perform a vacuuming operation on the detection box 1, thus forming a vacuum cavity 111 inside the detection box 1. There are two liquid nitrogen transfer flanges 112, which can cooperate with the detection unit to realize the input and output of liquid nitrogen, thereby cooling the battery 8 under test.

[0046] The driving unit 3, clamping unit 2, and detection unit are installed in the cavity 111. Specifically, in this embodiment, a base 13 is installed inside the cavity 111, and the driving unit 3, clamping unit 2, and detection unit are sequentially connected to the base 13. Figure 5 , Figure 8 As shown, the base 13 includes a base plate 131 and a clamping plate 132. The drive unit 3, clamping unit 2, and detection unit can be detachably mounted on the base 13 using screws. The clamping plate 132 restricts the position of each unit from both the left and right ends, making the contact between the units tighter and occupying less space. In use, the operator can first install the drive unit 3, clamping unit 2, and detection unit onto the base 13 in sequence, then install the base 13 into the cavity 111, and finally install the cover plate 12 onto the outer shell 11. The operation is simple, facilitates the replacement of damaged parts, and extends the service life. Of course, in other embodiments, the base 13 may not be installed inside the cavity 111, and the drive unit 3, clamping unit 2, and detection unit may be directly installed inside the outer shell 11. There are no specific restrictions.

[0047] like Figure 4 As shown, the cover plate 12 has an opening 121 on its surface, which faces the battery 8 under test on the clamping unit 2 to facilitate observation of the battery 8 under a scanning electron microscope. The cover plate 12 is slidably connected to a movable baffle 16 to cover or open the opening 121. When the movable baffle 16 slides and covers the opening 121, the cavity 111 forms a closed space, and the inside of the test chamber 1 is evacuated through the vacuum cable connector 113, so that the cavity 111 reaches a vacuum state, placing the battery 8 under test in a vacuum environment and preventing the battery 8 under test from being contaminated by external impurities.

[0048] Specifically, such as Figure 4 Taking the direction shown as an example, the movable baffle 16 slides towards the opening 121 until it abuts against the cover plate 12, thus blocking the opening 121 and forming a closed space in the cavity 111. In this embodiment, the middle part of the cover plate 12 is recessed to form a groove 122. The groove 122 extends along the length of the cover plate 12, and the width of the groove 122 is the same as the width of the movable baffle 16. The movable baffle 16 can slide left and right relative to the cover plate 12 along the groove 122. When the movable baffle 16 abuts against the non-recessed part on the right side of the cover plate 12, the movable baffle 16 completely blocks the opening 121, forming a closed space inside the test box 1. This ensures that the battery under test 8 does not come into contact with the outside world, thereby reducing the influence of external impurities on the battery under test 8 and ensuring the accuracy of the test.

[0049] To further enhance the sealing performance of the testing chamber 1, both the outer shell 11 and the cover plate 12 have sealing grooves 114 on their surfaces. These sealing grooves 114 are used to accommodate O-ring seals. Figure 6 , Figure 7As shown, the upper surface of the outer casing 11 has a sealing groove 114. After an O-ring (not shown in the figure) is placed in the sealing groove 114, the O-ring abuts against the cover plate 12 above the outer casing 11 and is squeezed by the cover plate 12, making the cover plate 12 and the outer casing 11 tightly connected, preventing impurities in the air from entering. Similarly, the side wall of the outer casing 11 where the liquid nitrogen transfer flange 112 is located also has a sealing groove 114, and the O-ring ensures the sealing of the side wall of the outer casing 11. Figure 3 , Figure 4 As shown, the upper surface of the cover plate 12 also has a sealing groove 114. The sealing groove 114 surrounds the opening 121. During the sliding process of the movable baffle 16, the movable baffle 16 contacts the O-ring and squeezes the O-ring, so that the opening 121 is completely sealed by the movable baffle 16, thereby forming a completely closed sealed space inside the detection box 1. At the same time, the friction generated by the compression between the movable baffle 16 and the O-ring can further fix the sliding position of the movable baffle 16, ensuring that the opening 121 is blocked.

[0050] In this embodiment, the shape and size of the sealing groove 114 vary depending on its location, and the corresponding size and specifications of the O-ring are also different. The O-ring is made of rubber, which has stable performance, is an existing material, and is easy to obtain.

[0051] like Figures 1-5 As shown, an elastic element 15 is connected to the surface of the cover plate 12. The elastic element 15 includes a fixed seat 151, a fixed support 152, and a tension spring 153. The fixed seat 151 is fixedly connected to the cover plate 12. One end of the fixed support 152 is fixedly connected to the fixed seat 151, and the other end is connected to the tension spring 153. The other end of the tension spring 153 is connected to a movable baffle 16. Pushing the movable baffle 16 to slide towards the opening 121 causes the tension spring 153 to deform and stretch. After releasing the movable baffle 16, the tension spring 153 returns to its original deformation, causing the movable baffle 16 to automatically reset.

[0052] In addition, both the movable baffle 16 and the cover plate 12 are provided with positioning holes 162, specifically as follows: Figure 4As shown, the movable baffle 16 has a positioning hole 162 on the side near the opening 121. After the movable baffle 16 slides against the cover plate 12, the corresponding position of the cover plate 12 also has a positioning hole 162. Screws are inserted into the positioning holes 162 of the movable baffle 16 and the cover plate 12 to fix the sliding position of the movable baffle 16, preventing the movable baffle 16 from automatically resetting under the tension of the tension spring 153, thereby continuously blocking the opening 121 and sealing the cavity 111. When it is necessary to open the opening 121, the screw in the positioning hole 162 can be manually removed, and the movable baffle 16 will automatically reset under the tension of the tension spring 153. There is no need to manually drive the movable baffle 16 to reset, which is simple, time-saving and labor-saving. At the same time, after the movable baffle 16 slides, it can abut against the cover plate 12, which limits the movement distance of the movable baffle 16, so that the tension spring 153 can be used within the allowable extension length range, avoiding failure due to excessive extension distance.

[0053] To further restrict the movement direction of the movable baffle 16, such as Figure 1 Taking the direction shown as an example, the cover plate 12 is connected to the positioning baffle 17, which is located above the movable baffle 16. The positioning baffle 17 has a guide groove 171, and the movable baffle 16 has a positioning post 161 on its surface. The positioning post 161 extends out of the guide groove 171 and slides along the guide groove 171. Applying an external force pushes the positioning post 161 to move in the direction of the opening 121, thereby driving the movable baffle 16 to move. Specifically, as shown... Figure 4 As shown, the positioning post 161 includes a neck 1611 and a protrusion 1612. The protrusion 1612 is located at the top of the neck 1611 and increases radially. The neck 1611 is placed in the guide groove 171. Pushing the protrusion 1612 can make the neck 1611 slide in the guide groove 171, thereby driving the movable baffle 16 to slide. The guide groove 171 extends along the length of the positioning baffle 17 to restrict the positioning post 161 from making linear movements along the guide groove 171. The guide groove 171 is open to the side facing the opening 121, so that the positioning post 161 can drive the movable baffle 16 to slide a sufficient distance to achieve the abutment between the movable baffle 16 and the cover plate 12.

[0054] Regarding how to perform vacuuming operation on the test box 1 to transfer the battery 8 under test under vacuum, the test box 1 in this utility model can not only be connected to existing vacuuming equipment through vacuum cable connector 113, but also be used in conjunction with the current mainstream glove box.

[0055] Specifically, the test chamber 1 is placed inside the glove box and a vacuum is drawn. The positioning column 161 is manually pulled, which in turn causes the movable baffle 16 to slide along the slide groove 122. The tension spring 153 is stretched. When the movable baffle 16 abuts against the cover plate 12, the opening 121 is blocked. The movable baffle 16 and the cover plate 12 are connected and fixed by screws to prevent the tension spring 153 from rebounding and pulling the movable baffle 16. The cover plate 12 compresses the O-ring seal, so that a sealed vacuum cavity 111 is formed inside the test chamber 1.

[0056] Remove the test chamber 1 from the glove box and remove the screws between the movable baffle 16 and the cover plate 12. Since the cavity 111 of the test chamber 1 is a vacuum, a pressure difference is formed with the outside atmosphere, which makes the movable baffle 16 unable to move due to external pressure. Under the action of the pressure difference, the friction between the movable baffle 16 and the O-ring seal increases, making it impossible for the movable baffle 16 to be pulled open by the tension spring 153. Thus, the test chamber 1 is closed in a vacuum state. Therefore, during the process of transferring the test chamber 1 from the glove box to the scanning electron microscope, the battery under test 8 is always in a vacuum environment, which avoids the battery under test 8 being contaminated by oxygen, moisture or dust in the gas environment of the air and other media during the transfer process, thereby realizing the vacuum transfer of the battery under test 8.

[0057] After the test chamber 1 is transferred into the scanning electron microscope, the vacuum cable connector 113 is connected to the vacuum connector in the scanning electron microscope through the cable to perform a vacuum operation on the scanning electron microscope, so that the pressure difference between the inside and outside of the test chamber 1 disappears and the friction is reduced. At this time, under the action of the tension spring 153, the moving baffle 16 automatically moves back along the slide groove 122 to open the opening 121, so that the battery under test 8 is exposed under the scanning electron microscope for easy observation.

[0058] In this invention, the testing box 1 has multiple functions. The clamping unit 2 is used to hold the battery 8 under test and perform charge / discharge tests on the battery 8. The driving unit 3 can control the output pressure load on the battery 8 under test. Figure 5 As shown, the detection unit includes a heating component 4, a cooling component 5, a temperature measuring component 6, and a force detection component 7. The heating component 4 and cooling component 5 provide heating and cooling functions to test the temperature of the battery under test 8. The temperature measuring component 6 detects temperature changes during heating and cooling, and the force detection component 7 performs pressure tests on the battery under test 8. This detection chamber 1 integrates pressure, heating, and cooling tests into a single unit. Combined with in-situ electrochemical testing, it can perform various testing methods such as cyclic voltammetry, linear scan, differential pulse voltammetry, square wave voltammetry, chronoamperometry, and AC impedance testing. It can perform charge and discharge tests on samples such as solid-state batteries, power batteries, and lithium-ion batteries in situ.

[0059] like Figure 9 , Figure 10As shown, the clamping unit 2 includes an insulating base 21, an electrochemical clamp positive electrode 22, an electrochemical clamp negative electrode 23, and ceramic screws 24 connecting the electrochemical clamp positive electrode 22 and the electrochemical clamp negative electrode 23. Specifically, the insulating base 21 is fixed to the force-bearing base 12 by screws. The insulating base 21 has a U-shaped cross-section with the opening facing upwards, and is used to place the electrochemical clamp positive electrode 22 and the electrochemical clamp negative electrode 23. In other words, the electrochemical clamp positive electrode 22 and the electrochemical clamp negative electrode 23 are only placed on the insulating base 21 and are not fixedly connected, so the electrochemical clamp positive and negative electrodes can be manually removed from the insulating base 21.

[0060] Ceramic screws 24 connect the positive electrode 22 and the negative electrode 23 of the electrochemical fixture, creating a gap to allow space for the installation of the battery under test 8. The shape and size of the battery under test 8 vary within the range of this gap. The battery under test 8 is clamped between the positive and negative electrodes of the electrochemical fixture. During testing, the electrochemical workstation is connected to the positive and negative electrodes of the electrochemical fixture, enabling the charging and discharging of the battery under test 8. Simultaneously, the gap between the positive electrode 22 and the negative electrode 23 ensures that current flows only through the positive electrode 22, through the battery under test 8, and then to the negative electrode 23, preventing parallel circuits. In this embodiment, the insulating base 21 is made of ceramic material, isolating the positive and negative electrodes of the electrochemical fixture from other metal parts. The ceramic screws 24 are also made of ceramic to prevent current from flowing through the screws to the positive and negative electrodes of the electrochemical fixture.

[0061] like Figure 11 As shown, the surface of the negative electrode 23 of the electrochemical fixture has a hexagonal countersunk hole 25 for mounting the nut of the ceramic screw 24. The depth of the hexagonal countersunk hole 26 is greater than the thickness of the nut, which allows for displacement after the battery 8 under test is subjected to pressure. The length of the ceramic screw 24 extending into the positive and negative electrodes of the electrochemical fixture is adjusted in time by the nut to avoid stress on the ceramic screw 24.

[0062] In addition, such as Figure 5 As shown, the positive electrode 22 of the electrochemical clamp is in contact with the heating component 4, and the negative electrode 23 of the electrochemical clamp is in contact with the cooling component 5, so that the heat source or cold source can be conducted to the battery under test 8 through contact, thereby realizing the temperature test of the battery under test 8.

[0063] like Figures 12-14As shown, the drive unit 3 includes an eight-bar displacement amplification flexible hinge 31 and a piezoelectric ceramic actuator 32. The piezoelectric ceramic actuator 32 is installed inside the eight-bar displacement amplification flexible hinge 31. Specifically, the piezoelectric ceramic actuator 32 is cylindrical, with a socket 321 and a boss 322 at each end. One end of the piezoelectric ceramic actuator 32 is threaded to the eight-bar displacement amplification flexible hinge 31 through the socket 321, and the other end is fastened with a fastener to secure the boss 322 to the eight-bar displacement amplification flexible hinge 31. This installation method ensures that the piezoelectric ceramic actuator 32 and the eight-bar displacement amplification flexible hinge 31 are installed tightly without gaps.

[0064] like Figure 5 , Figure 12 , Figure 15 As shown, one side of the eight-bar displacement amplification flexible hinge 31 is fixed to the force-bearing base 12 by screws, and the other side is connected and fixed to the heating component 4 by screws. During use, the piezoelectric ceramic actuator 32 outputs a micro-displacement axially under the action of the inverse piezoelectric effect. The micro-displacement acts on the eight-bar displacement amplification flexible hinge 31, and after being amplified by the eight-bar displacement amplification flexible hinge 31, a larger displacement can be output. By controlling the alternating electric field applied to the piezoelectric ceramic actuator 32, the magnitude of the output displacement can be controlled, thereby indirectly controlling the compressive force value acting on the battery under test 8. Compared with the traditional motor-driven pressure loading method, this utility model uses the combination of the eight-bar displacement amplification flexible hinge 31 and the piezoelectric ceramic actuator 32, which has the advantages of high precision, high resolution, fast response speed, compact structure, and output pressure load greater than 2000N.

[0065] like Figure 16 , Figure 17 As shown, the heating assembly 4 includes a heating fixing plate 41, an insulating pressure head A42 fixedly connected to the heating fixing plate 41, and a resistance heater 43. The heating fixing plate 41 has a through hole 411. The resistance heater 43 is cylindrical and installed in the through hole 411. A screw passes through a threaded hole on the heating fixing plate 41 to securely clamp the resistance heater 43, ensuring full contact between the two. The resistance heater 43 is energized and heated. After passing through the heating fixing plate 41, the heat is transferred to the battery under test 8 via the positive electrode 22 of the electrochemical clamp, thus achieving the heating function of the battery under test 8.

[0066] In this embodiment, there are two through holes 411, located at the left and right ends of the heating fixing plate 41. Correspondingly, there are also two resistance heaters 43, one on the left and one on the right, heating simultaneously to improve the heating speed and ensure more uniform temperature transfer to the battery 8 under test.

[0067] like Figure 18 , Figure 19As shown, the refrigeration assembly 5 includes a liquid nitrogen refrigeration plate 51 and an insulating pressure head B52 fixedly connected to the liquid nitrogen refrigeration plate 51. The liquid nitrogen refrigeration plate 51 is internally connected and has transmission pipes 53 on both sides for transmitting liquid nitrogen. Specifically, with Figure 5 , Figure 19 Taking the direction shown as an example, the external nitrogen storage device, liquid nitrogen transmission flange 112 and transmission pipe 53 are connected together through the conduit. Liquid nitrogen flows through the left liquid nitrogen transmission flange 112, through the left transmission pipe 53, and then into the liquid nitrogen cooling plate 51. After flowing through the right transmission pipe 53 and through the right liquid nitrogen transmission flange 112, it is output, forming the liquid nitrogen transmission route. Among them, the liquid nitrogen cold source is transferred to the battery under test 8 through the liquid nitrogen cooling plate 51 and the electrochemical clamp negative electrode 23, so as to realize the cooling function of the battery under test 8.

[0068] In this embodiment, both the insulating pressure head A42 and the insulating pressure head B52 are made of silicon nitride material, and their pressure resistance and insulation characteristics are suitable for electrochemical testing and compression testing of the battery under test 8.

[0069] like Figure 16 , Figure 19 As shown, the top of the insulating pressure head A42 has a countersunk hole 421, and the surface of the liquid nitrogen cooling plate 51 also has a countersunk hole 421. The countersunk hole 421 can be used to place the temperature measuring component 6. Specifically, the temperature measuring component 6 consists of two cylindrical platinum resistance thermometers 61, specifically PT100 platinum resistance thermometers 61, which are installed in the countersunk holes 421 of the insulating pressure head A42 and the liquid nitrogen cooling plate 51, respectively, so as to facilitate timely detection of heating and cooling temperatures.

[0070] like Figures 20-22 As shown, the force detection assembly 7 includes a pressure sensor 71, a connecting rod 72, and a guide seat 73, so as to... Figure 22 Taking the direction shown as an example, the right end of the connecting rod 72 is connected to the insulating pressure head B52 by a screw, and the left end of the connecting rod 72 is hollow and sleeved on the pressure sensor 71; the guide seat 73 is a hollow sleeve, and the end of the pressure sensor 71 is cylindrical, passing through the interior of the guide seat 73 and extending out of the guide seat 73. The guide seat 73 is connected to the force-bearing base 12 by a screw. In this embodiment, the pressure sensor 71 is specifically a spiral pressure sensor. When the driving unit 3 applies pressure to the battery 8 under test, the pressure sensor 71 can promptly measure the pressure value of the battery 8 under test, which is existing technology and convenient to use.

[0071] In this embodiment, the overall dimensions of the testing box are 173mm*123mm*51mm. It is small in size and light in weight, and can be placed in vacuum glove boxes of various brands to draw a vacuum. It can also be fixedly connected to various scanning electron microscope platforms by screws. By combining it with a scanning electron microscope, the microstructure evolution of the positive and negative electrodes of the battery under test 8 during the charging and discharging process and the corresponding relationship with the electrical performance can be observed. This allows for in-situ, real-time, and dynamic observation of the sample morphology of the battery under test 8 under different temperatures and pressure loads, while obtaining information such as scanning images, electrochemical performance, and elemental distribution.

[0072] The process of using this utility model is as follows: First, prepare for the test by assembling the battery 8 to be tested, placing the test box 1 in the glove box to draw a vacuum, taking out the positive and negative electrodes of the electrochemical clamp on the insulating base 21, turning the ceramic screw 24 with an Allen wrench to separate the positive electrode 22 and the negative electrode 23 of the electrochemical clamp, fixing the battery 8 to be tested to the protruding position on the surface of the negative electrode 23 of the electrochemical clamp with conductive glue, then connecting the positive electrode 22 and the negative electrode 23 of the electrochemical clamp with the ceramic screw 24, and then reinstalling it on the insulating base 21.

[0073] Manually pull the positioning column, which in turn causes the movable baffle 16 to slide along the slide groove 122. The tension spring 153 is in a stretched state. When the movable baffle 16 abuts against the cover plate 12, the opening 121 is blocked. The movable baffle 16 and the cover plate 12 are connected and fixed by screws. The cover plate 12 compresses the O-ring seal to achieve a vacuum seal inside the test box 11.

[0074] Then, the testing apparatus is transferred under vacuum. The test chamber 1 is removed from the glove box, and the screws between the movable baffle 16 and the cover plate 12 are removed. Because the inside of the test chamber 1 is under vacuum, a pressure difference is created between it and the atmosphere, causing external pressure on the movable baffle 16. The movable baffle 16 and the cover plate 12 remain tightly sealed. The test chamber 1 is then transferred to the scanning electron microscope (SEM) chamber and fixed on the SEM stage. The vacuum cable connector 113 is connected to the vacuum connector in the SEM via a cable. A vacuum is then evacuated from the SEM, causing the pressure difference inside and outside the test chamber 1 to become uniform. The movable baffle 16 slides back under the tension of the tension spring 153, exposing the opening 121, thus exposing the battery 8 to be tested directly below the SEM.

[0075] The device was then connected to an electrochemical workstation and a multi-functional integrated controller via external cables. The electrochemical workstation controlled the charging and discharging of the test battery 8, while the multi-functional integrated controller controlled pressure loading, heating, and cooling. During the test, the evolution of the positive and negative electrode composition, morphology, and structure of the test battery 8, its correlation with electrical performance, and the effects of pressure and temperature on battery performance were observed using a scanning electron microscope. After the experiment, the scanning electron microscope was degassed, and the test battery 8 was subjected to final recovery processing.

[0076] The above specific embodiments are used to explain and illustrate the present utility model, and are not intended to limit the present utility model. Any modifications and changes made to the present utility model within the spirit and scope of the claims shall fall within the protection scope of the present utility model.

Claims

1. A multifunctional battery electrochemical testing device, characterized in that, include: The test box (1) includes an outer shell (11) and a cover plate (12) detachably connected to the outer shell (11). The outer shell (11) forms a cavity (111) inside. The side wall of the outer shell (11) has a vacuum cable connector (113) for communicating with the inside and outside of the cavity (111). The surface of the cover plate (12) has an opening (121). The cover plate (12) is slidably connected to a movable baffle (16) for blocking or opening the opening (121). Clamping unit (2) is used to clamp the battery to be tested (8); The drive unit (3) is used to control the output pressure load on the battery under test (8); The detection unit is used to perform comprehensive testing on the battery under test (8); The drive unit (3), clamping unit (2) and detection unit are installed in the cavity (111). The opening (121) is directly opposite the clamping unit (2). The moving baffle (16) slides and blocks the opening (121). The cavity (111) enters a closed state. It can be evacuated through the vacuum cable connector (113) so that the cavity (111) and the battery under test (8) are in a vacuum environment and a pressure difference is formed inside and outside the cavity (111).

2. The battery electrochemical testing device according to claim 1, characterized in that: The cover plate (12) is connected to an elastic element (15), which includes a fixed seat (151), a fixed support (152) and a tension spring (153). The fixed seat (151) is fixedly connected to the cover plate. One end of the fixed support (152) is fixedly connected to the fixed seat (151), and the other end is connected to the tension spring (153). The other end of the tension spring (153) is connected to a movable baffle (16). The movable baffle (16) is pushed to slide towards the opening (121), and the tension spring (153) is deformed and stretched. The movable baffle (16) and the cover plate (12) are both provided with positioning holes (162). The movable baffle (16) and the cover plate (12) can be connected by screws to fix the sliding position of the movable baffle (16).

3. The battery electrochemical testing device according to claim 1, characterized in that: The outer shell (11) and the cover plate (12) both have sealing grooves (114) on their surfaces. The sealing grooves (114) are used to place O-ring seals. The side wall of the outer shell (11) also has a liquid nitrogen transfer flange (112). The liquid nitrogen transfer flange (112) is connected to the detection unit to transfer liquid nitrogen to the detection unit.

4. The battery electrochemical testing device according to claim 2, characterized in that: The cover plate (12) is connected to the positioning baffle (17), which has a guide groove (171). The movable baffle (16) has a positioning post (161) on its surface. The positioning post (161) extends out of the guide groove (171) and can slide along the guide groove (171). An external force is applied to push the positioning post (161) to move in the direction of the opening, thereby moving the movable baffle (16).

5. The battery electrochemical testing device according to claim 1, characterized in that: The cavity (111) is equipped with a base (13), and the drive unit (3), clamping unit (2) and detection unit are sequentially mounted on the base (13). The clamping unit (2) includes a U-shaped insulating base (21), an electrochemical clamp positive electrode (22), an electrochemical clamp negative electrode (23), and a ceramic screw (24) connecting the electrochemical clamp positive electrode (22) and the electrochemical clamp negative electrode (23). The surface of the electrochemical clamp negative electrode (23) has a hexagonal countersunk hole (25) for mounting the ceramic screw (24).

6. The battery electrochemical testing device according to claim 1, characterized in that: The drive unit (3) includes an eight-bar displacement amplification flexible hinge (31) and a piezoelectric ceramic actuator (32). The piezoelectric ceramic actuator (32) is cylindrical and has a socket (321) and a boss (322) at both ends. One end of the piezoelectric ceramic actuator (32) is threaded to the eight-bar displacement amplification flexible hinge (31) through the socket (321), and the other end is fastened with a fastener to fasten the boss (322) to the eight-bar displacement amplification flexible hinge (31).

7. The battery electrochemical testing device according to claim 1, characterized in that: The detection unit includes a heating component (4), a cooling component (5), a temperature measuring component (6), and a force detection component (7). The heating component (4) includes a heating fixing plate (41), an insulating pressure head A (42) fixedly connected to the heating fixing plate (41), and a resistance heater (43). The heating fixing plate (41) has a through hole (411), and the resistance heater (43) is disposed in the through hole (411). The insulating pressure head A (42) has a countersunk hole (421) at the top for mounting the temperature measuring component (6).

8. The battery electrochemical testing device according to claim 7, characterized in that: The refrigeration assembly (5) includes a liquid nitrogen refrigeration plate (51) and an insulating pressure head B (52) fixedly connected to the liquid nitrogen refrigeration plate (51). The liquid nitrogen refrigeration plate (51) is internally connected and has a transmission pipe (53) for transmitting liquid nitrogen and a round countersunk hole (421) on both sides.

9. The battery electrochemical testing device according to claim 8, characterized in that: The temperature measuring component (6) includes two platinum resistance thermometers (61), which are cylindrical and are placed in the countersunk holes (421) of the insulating pressure head A (42) and the liquid nitrogen cooling plate (51), respectively.

10. The battery electrochemical testing device according to claim 7, characterized in that: The force detection component (7) includes a pressure sensor (71), a connecting rod (72) and a guide seat (73). One end of the connecting rod (72) is connected to the insulating pressure head B (52), and the other end is connected to the pressure sensor (71). The end of the pressure sensor (71) is cylindrical and passes through the guide seat (73). The guide seat (73) is connected to the base (13).

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