An inflation pressure detection and constant pressure control device

Abstract

The utility model discloses an expansion pressure detection and constant voltage control device belongs to battery test technical field, and this device includes pressure -bearing subassembly and base, and pressure -bearing subassembly can supply battery sample assembly, and pressure -bearing subassembly can slide relative to base, and pressure -bearing subassembly is equipped with constant force spring group between base, and is equipped with displacement monitoring subassembly on base, and is equipped with pressure -tight subassembly on pressure -bearing subassembly, and pressure -tight subassembly is pressure -tight to battery sample on pressure -bearing subassembly, and is equipped with pressure sensing subassembly on pressure -tight subassembly, and when alloy negative electrode volume expansion appears with the charging process of battery sample, and battery sample pushes pressure -tight subassembly, and pushing force is gathered by pressure sensing subassembly, and pressure -bearing subassembly generates displacement relative to base, and is gathered by displacement monitoring subassembly. The utility model can realize to solid -state battery single body exert and keep near constant pressure and carry out online detection to alloy negative electrode's expansion pressure simultaneously, and provide experimental basis for solid -state battery interface stability, safety, cycle life and engineering amplification design.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery testing technology, and particularly relates to an expansion pressure detection and constant pressure control device. Background Technology

[0002] In solid-state batteries, the use of high-capacity alloy anodes (such as silicon-based, tin-based, or lithium metal / lithium alloy anodes) can significantly improve energy density. However, these alloy anodes often experience significant volume expansion and contraction during lithium insertion / extraction, leading to the following problems: a sharp increase in interfacial stress between the anode and the solid electrolyte, potentially causing solid-solid interface delamination and cracking, increased interfacial resistance, and decreased cycle life. Excessive expansion pressure may crush the brittle inorganic solid electrolyte, triggering short circuits and safety risks. On the other hand, solid-state batteries often require a certain level of stacking pressure (applied pressure) to maintain good interfacial contact. If the pressure is too low, the interface will lose contact; if the pressure is too high, it will crush the electrode / electrolyte structure. Therefore, a "constant and controllable" external pressure is itself a very critical boundary condition in solid-state battery evaluation.

[0003] Existing experimental setups generally suffer from two main shortcomings: One type uses simple screw / pressor-type button cell clamps, which rely solely on manual screw tightening to apply initial pressure. As the battery thickness changes during charging and discharging, the external pressure becomes uncontrollable and cannot be maintained at a constant pressure. Furthermore, it cannot provide real-time, quantitative readings of the reaction force generated by the expansion of the negative electrode. The other type uses material mechanics testing benches or universal testing machines. While these can measure force and displacement, their large size and open structure make it difficult to maintain electrochemical cycling conditions for extended periods in inert atmospheres such as glove boxes, hindering practical testing of solid-state batteries.

[0004] Therefore, there is an urgent need to design an expansion pressure detection and constant pressure control device to solve the problems mentioned above. Utility Model Content

[0005] The purpose of this invention is to provide an expansion pressure detection and constant pressure control device, which has the advantages of providing an approximately constant external clamping force during the working process of the battery sample, and can also detect the change of expansion pressure of the alloy negative electrode with the cycle in real time, thereby realizing the in-situ quantification of mechanical behavior and solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the specific technical solution of the expansion pressure detection and constant pressure control device of this utility model is as follows: An expansion pressure detection and constant pressure control device includes a pressure-bearing component and a base. The pressure-bearing component is for assembling battery samples and can slide relative to the base. A constant force spring assembly is provided between the pressure-bearing component and the base to compensate for changes in the thickness of the battery sample and maintain constant pressure. A displacement monitoring component is provided on the base, and a clamping component is provided on the pressure-bearing component. The clamping component presses the battery sample on the pressure-bearing component. A pressure sensing component is provided on the clamping component. When the volume of the alloy negative electrode of the battery sample expands during the charging process, the battery sample pushes against the clamping component. The pushing force is collected by the pressure sensing component to obtain an expansion pressure signal. At the same time, the pressure-bearing component displaces relative to the base, which is collected by the displacement monitoring component to obtain a spring compression deformation signal.

[0007] Furthermore, a support column assembly is fixedly connected to the base, and the pressure-bearing component can slide relative to the base along the support column assembly.

[0008] Furthermore, the constant force spring assembly is sleeved on the support column assembly, with both ends of the constant force spring assembly abutting against the base and the pressure-bearing component, respectively.

[0009] Furthermore, the pressure-bearing component includes a pressure plate, on which a sample chamber is provided for accommodating battery samples.

[0010] Furthermore, the pressure plate is provided with a first loading post and a first conductive copper post. The lower end of the first loading post is connected to the pressure plate, and the upper end of the first loading post faces the battery sample. The first conductive copper post is inserted into the first loading post to provide an electrical connection path.

[0011] Furthermore, a first insulating pad is connected to the pressure plate, and the lower end of the first loading column is connected to the first insulating pad on the pressure plate.

[0012] Furthermore, the clamping assembly includes a clamping end cap, which is sleeved on the support column assembly. The clamping end cap can move along the support column assembly until it clamps the battery sample on the pressure-bearing assembly. The pressure sensing assembly is located on the clamping end cap.

[0013] Furthermore, the top of the support column assembly is provided with a first thread, and a clamping nut is screwed onto the support column assembly through the first thread. After the clamping end cover is fitted onto the support column assembly, the clamping nut is rotated to make the clamping assembly clamp the battery sample. The compression amount of the constant force spring assembly is adjusted by controlling the rotation amount of the clamping nut.

[0014] Furthermore, the clamping end cap is provided with a second loading post and a second conductive copper post. The upper end of the second loading post is connected to the pressure sensing component, and the lower end of the second loading post faces the battery sample. The second conductive copper post is inserted into the second loading post to provide an electrical connection path.

[0015] Furthermore, a second insulating pad is connected to the pressure sensing component, and the upper end of the second loading column is connected to the second insulating pad on the pressure sensing component.

[0016] This invention has the following advantages: This device can simultaneously apply and maintain a near-constant pressure on solid-state battery cells and perform online detection of the expansion pressure on the alloy negative electrode, providing an experimental basis for the interface stability, safety, cycle life, and engineering scale-up design of solid-state batteries. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the expansion pressure detection and constant pressure control device of this utility model; Figure 2 This is an exploded structural diagram of the expansion pressure detection and constant pressure control device of this utility model; The markings in the diagram are as follows: 1. Compression nut; 2. Compression end cap; 3. Pressure sensing assembly; 4. Second insulating pad; 5. First thread; 6. Second loading column; 7. Second conductive copper column; 8. Sample chamber; 9. First loading column; 10. First conductive copper column; 11. First insulating pad; 12. Pressure plate; 13. Support column assembly; 14. Constant force spring assembly; 15. Displacement monitoring assembly; 16. Base. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0020] The following is a reference to the appendix. Figure 1 To be continued Figure 2 This invention describes an expansion pressure detection and constant pressure control device.

[0021] Currently, existing experimental setups generally suffer from several problems. They can only apply an initial pressure by manually tightening screws. Once the thickness of the battery changes during charging and discharging, the external pressure becomes uncontrollable and cannot be kept constant. Alternatively, they are large in size and have open structures, making it difficult to maintain electrochemical cycling conditions for a long time in inert atmospheres such as glove boxes. These issues are not conducive to the practical testing and use of solid-state batteries.

[0022] Therefore, this expansion pressure detection and constant pressure control device includes a pressure-bearing component and a base 16. The pressure-bearing component is used for assembling battery samples and can slide relative to the base 16. A constant force spring assembly 14 is provided between the pressure-bearing component and the base 16. The constant force spring assembly 14 compensates for changes in the thickness of the battery sample and maintains constant pressure. A displacement monitoring component 15 is provided on the base 16, and a clamping component is provided on the pressure-bearing component. The clamping component clamps the battery sample on the pressure-bearing component. A pressure sensing component 3 is provided on the clamping component. When the volume of the alloy negative electrode of the battery sample expands during the charging process, the battery sample pushes against the clamping component. The pushing force is collected by the pressure sensing component 3 to obtain the expansion pressure signal. The pressure-bearing component is displaced relative to the base 16, and the displacement monitoring component 15 collects the spring compression deformation signal.

[0023] The battery samples are solid-state or semi-solid-state batteries.

[0024] Preferably, the pressure sensing component 3 can adopt a columnar strain gauge structure, which is convenient for coaxial installation, has a compact structure, and is also convenient for sealing and wiring. It can be a force sensing ring or a strain gauge pressure sensor. In other embodiments of this utility model, the pressure sensing component 3 can also adopt other forms of structure, as long as it can ensure that the jacking force is collected.

[0025] The displacement monitoring component 15 can be any one of a linear displacement sensor, an LVDT displacement sensor, an inductive displacement probe, or an ultrasonic displacement sensor. The displacement monitoring component 15 is fixedly connected to the base 16 to output data on the change of axial displacement over time in real time during the solid-state battery cycle.

[0026] The signal output terminals of the pressure sensing component 3 and the displacement monitoring component 15 can be led out to external testing instruments via leads to realize online recording, curve plotting and data analysis of the expansion pressure of the alloy negative electrode.

[0027] This device integrates constant pressure control and expansion pressure detection, solving the shortcomings of traditional fixtures that cannot simultaneously achieve constant pressure and real-time detection. Furthermore, through the automatic displacement compensation of the constant force spring assembly 14, the external force remains stable when the battery thickness changes, avoiding pressure drift problems and simulating the stacking conditions required for the actual operation of solid-state batteries. Moreover, through the coordinated operation of the pressure sensing component 3 and the displacement monitoring component 15, a dual-signal acquisition system is formed, which can quantify the expansion behavior of the alloy negative electrode in situ and provide pressure-time or pressure-capacity curves, providing key data for interface stability assessment.

[0028] A support column assembly 13 is fixedly connected to the base 16. The pressure-bearing component can slide relative to the base 16 along the support column assembly 13. Specifically, the support column assembly 13 is provided with a second thread, and the base 16 is provided with a screw hole. The support column assembly 13 is screwed into the screw hole on the base 16 through the second thread to fix the base 16 and the support column assembly 13.

[0029] The support column assembly 13 forms a rigid frame connecting the base 16 and the pressure-bearing component, which can withstand axial loads and prevent skewing, ensuring the coaxiality of the force transmission path. The support column assembly 13 makes the clamping component, the pressure-bearing component and the base 16 form an integral frame.

[0030] The constant force spring assembly 14 is sleeved on the support column assembly 13. The two ends of the constant force spring assembly 14 abut against the base 16 and the pressure-bearing component, respectively. The constant force spring assembly 14 uses the column as a guide structure to ensure that the constant force spring assembly 14 moves axially when compressed / extended, preventing torsion or eccentricity, thereby outputting a more constant force.

[0031] The support column group 13 includes multiple support columns, and the constant force spring group 14 includes multiple constant force springs. The specific number of support columns is the same as the specific number of constant force springs. Each constant force spring is sleeved on its corresponding support column. The support columns and constant force springs are distributed circumferentially. Preferably, there are three support columns and three constant force springs. In other embodiments of this utility model, the number of support columns and constant force springs may also be other.

[0032] A constant force spring is made up of several helical compression springs stacked in series, parallel or series-parallel combination to obtain a basically constant output force within the working stroke range.

[0033] The pressure-bearing assembly includes a pressure plate 12, on which a sample chamber 8 is provided for housing battery samples. Specifically, the sample chamber 8 is made of an insulating material compatible with solid electrolytes, preferably polyetheretherketone (PEEK) or a ceramic bushing structure, to avoid electrical short circuits between the electrodes and metal supports during loading and to improve the chemical stability of the solid battery interface. The sample chamber 8 can be replaced with different sizes or inner lining materials as needed to adapt to sheet-like, laminated, or small stacked solid battery cell / half-cell structures and to support different types of high-expansion alloy anode systems.

[0034] The sample chamber 8 is detachably connected to the pressure plate 12 to facilitate quick replacement of battery samples in an inert atmosphere glove box without replacing the entire device.

[0035] The pressure plate 12 is provided with a first loading post 9 and a first conductive copper post 10. The lower end of the first loading post 9 is connected to the pressure plate 12, and the upper end of the first loading post 9 faces the battery sample. The first conductive copper post 10 is inserted into the first loading post 9 to provide an electrical connection path. The first loading post 9 is responsible for mechanical loading, and the first conductive copper post 10 is responsible for electrical connection. The mechanical and electrochemical tests are combined to ensure that current is conducted while pressure is applied, simulating the actual working state of the battery.

[0036] A first insulating pad 11 is connected to the pressure plate 12. The lower end of the first loading column 9 is connected to the first insulating pad 11 on the pressure plate 12. The first insulating pad 11 blocks the transmission of electrical signals, prevents short circuits between metal parts, ensures that the pressure detection signal is not subject to electromagnetic interference, improves data accuracy, and can also buffer mechanical stress. Its advantages are that it extends the life of the components and is suitable for high cycle testing.

[0037] The clamping assembly includes a clamping end cap 2, which is sleeved on the support column assembly 13. The clamping end cap 2 can move along the support column assembly 13 until it clamps the battery sample on the pressure-bearing assembly. The pressure sensing assembly 3 is located on the clamping end cap 2 and is located on the force transmission path to collect the expansion thrust of the battery sample in real time. It has a fast response and small error.

[0038] Furthermore, the top of the support column assembly 13 is provided with a first thread 5, and the support column assembly 13 is screwed with a clamping nut 1 through the first thread 5. After the clamping end cover 2 is fitted onto the support column assembly 13, the clamping nut 1 is rotated to make the clamping assembly clamp the battery sample. By controlling the amount of rotation of the clamping nut 1, the compression amount of the constant force spring assembly 14 is adjusted. Through the first thread 5 and the clamping nut 1, the initial pressure can be finely adjusted to achieve a repeatable set value and avoid the preload from loosening.

[0039] The clamping end cap 2 is provided with a second loading post 6 and a second conductive copper post 7. The upper end of the second loading post 6 is connected to the pressure sensing component 3, and the lower end of the second loading post 6 faces the battery sample. The second conductive copper post 7 is inserted into the second loading post to provide an electrical connection path.

[0040] The first loading post 9 and the second loading post 6 are located at both ends of the battery sample, respectively. The corresponding design of the first loading post 9 and the second loading post 6 ensures that the pressure is evenly distributed to the battery sample, avoiding local stress concentration that could lead to interface damage. Furthermore, the corresponding design of the first conductive copper post 10 and the second conductive copper post 7 forms a closed circuit, supporting the accuracy of charge and discharge tests.

[0041] A second insulating pad 4 is connected to the pressure sensing component 3, and the upper end of the second loading column 6 is connected to the second insulating pad 4 on the pressure sensing component 3.

[0042] The second insulating pad 4 is further used for electrical isolation to prevent electrical signals from interfering with the pressure sensing component, improve signal accuracy, and also buffer mechanical vibration, protect the sensitive pressure sensing component 3, and extend the service life of the device.

[0043] The testing and usage procedure for this expansion pressure detection and constant pressure control device is as follows: S1. Before the test, assemble the battery sample in the sample cavity 8 with the force-bearing surface facing upwards. S2. Tighten the clamping nut 1 to press the battery sample downward with the second loading column 6. At this time, the pressure plate 12 is subjected to an upward counter-force, and the force is transmitted to the base 16 through the constant force spring group 14. S3. By adjusting the screwing amount of the clamping nut 1, the compression amount of the constant force spring assembly 14 is controlled, so that the device reaches the target initial pressure. S4. When the volume of the alloy negative electrode of the battery sample expands during the charging process, the battery sample will push the second loading column 6 upward. This pushing force is collected in real time by the pressure sensing component 3 to obtain the expansion pressure signal, and will cause the pressure plate 12 to be displaced relative to the base 16. The displacement monitoring component 15 collects the spring compression deformation signal. Because of the use of constant force spring assembly 14, the output force within this displacement range is approximately constant, thus the external axial pressure acting on the solid-state battery sample remains basically constant, achieving constant pressure control.

[0044] S5. Throughout the entire battery sample cycle, the pressure signal of the pressure sensing component 3 and the spring displacement signal of the displacement monitoring component 15 can be continuously recorded to obtain the relationship between the expansion pressure and the number of cycles, charge / discharge capacity, SOC (state of charge), etc.

[0045] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An expansion pressure detection and constant pressure control device, characterized in that, The device includes a pressure-bearing component and a base. The pressure-bearing component is used for assembling battery samples and can slide relative to the base. A constant-force spring assembly is installed between the pressure-bearing component and the base to compensate for changes in the thickness of the battery sample and maintain constant pressure. A displacement monitoring component is installed on the base, and a clamping component is installed on the pressure-bearing component. The clamping component presses the battery sample on the pressure-bearing component and is equipped with a pressure sensing component. When the volume of the alloy negative electrode of the battery sample expands during the charging process, the battery sample pushes against the clamping component. The pushing force is collected by the pressure sensing component to obtain the expansion pressure signal. At the same time, the pressure-bearing component displaces relative to the base, which is collected by the displacement monitoring component to obtain the spring compression deformation signal.

2. The expansion pressure detection and constant pressure control device according to claim 1, characterized in that, A support column assembly is fixedly connected to the base, and the pressure-bearing component can slide relative to the base along the support column assembly.

3. The expansion pressure detection and constant pressure control device according to claim 2, characterized in that, The constant force spring assembly is sleeved on the support column assembly, and the two ends of the constant force spring assembly abut against the base and the pressure-bearing component, respectively.

4. The expansion pressure detection and constant pressure control device according to claim 1, characterized in that, The pressure-bearing assembly includes a pressure plate, on which a sample chamber is provided for housing battery samples.

5. The expansion pressure detection and constant pressure control device according to claim 4, characterized in that, The pressure plate is provided with a first loading post and a first conductive copper post. The lower end of the first loading post is connected to the pressure plate, and the upper end of the first loading post faces the battery sample. The first conductive copper post is inserted into the first loading post to provide an electrical connection path.

6. The expansion pressure detection and constant pressure control device according to claim 5, characterized in that, A first insulating pad is connected to the pressure plate, and the lower end of the first loading column is connected to the first insulating pad on the pressure plate.

7. The expansion pressure detection and constant pressure control device according to claim 2, characterized in that, The clamping assembly includes a clamping end cap, which is fitted onto the support column assembly. The clamping end cap can move along the support column assembly until it clamps the battery sample on the pressure-bearing assembly. The pressure sensing assembly is located on the clamping end cap.

8. The expansion pressure detection and constant pressure control device according to claim 7, characterized in that, The top of the support column assembly has a first thread, and a clamping nut is screwed onto the support column assembly through the first thread. After the clamping end cover is fitted onto the support column assembly, the clamping nut is rotated to make the clamping assembly clamp the battery sample. The compression amount of the constant force spring assembly is adjusted by controlling the amount of rotation of the clamping nut.

9. The expansion pressure detection and constant pressure control device according to claim 7, characterized in that, The clamping end cap is provided with a second loading post and a second conductive copper post. The upper end of the second loading post is connected to the pressure sensing component, and the lower end of the second loading post faces the battery sample. The second conductive copper post is inserted into the second loading post to provide an electrical connection path.

10. The expansion pressure detection and constant pressure control device according to claim 9, characterized in that, A second insulating pad is connected to the pressure sensing assembly, and the upper end of the second loading column is connected to the second insulating pad on the pressure sensing assembly.

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