System and method for testing cyclic expansion performance of solid-state battery

Abstract

The invention discloses a system and a method for testing the cyclic expansion performance of a solid-state battery, which can realize more accurate battery expansion detection. The test system comprises an oil storage tank, a static pressure container, a hydraulic control unit, a charging and discharging instrument and a main controller. The oil storage tank is used for storing hydraulic oil; the static pressure container comprises a closed container shell, a battery detection probe arranged on the container shell, and a first pressure gauge; the container shell is used for accommodating a battery to be detected and is provided with a first inlet and a first outlet of which the opening and closing states can be controlled; the inner side end of the battery detection probe is electrically connected with a tab of a battery to be detected; the first pressure gauge is used for detecting the pressure of liquid in the container shell; the hydraulic control unit is arranged between the oil storage tank and the static pressure container and used for achieving flowing of hydraulic oil between the oil storage tank and the first inlet and the first outlet of the static pressure container. The charging and discharging instrument is electrically connected with the outer side end of the battery detection probe; and the main controller is electrically connected with the hydraulic control unit and the charging and discharging instrument.

Description

Technical Field

[0001] This invention belongs to the field of battery expansion detection technology, and specifically refers to a system and method for testing the cycle expansion performance of solid-state batteries. Background Technology

[0002] In existing technologies, some batteries, such as lithium-ion batteries, expand to a certain extent during charging and discharging due to changes in their internal active materials. This expansion exerts a certain expansion force on the battery casing, causing changes in its thickness. In existing technologies, as the compaction density of battery materials increases, their expansion rate also increases, leading to significant thickness changes after a certain period of use. This negatively impacts battery life and the parallel assembly of multiple batteries. Therefore, to optimize battery module design, it is necessary to continuously charge and discharge the battery to monitor its expansion data throughout its entire lifespan.

[0003] Currently, battery expansion detection typically involves using a pressure plate with a pressure sensor in the equipment or tooling to press the battery onto a support plate, then powering on the battery and reading the changes in the pressure sensor values ​​to detect expansion. When experiments require high precision, this detection method is no longer sufficient because: (1) Batteries are usually flat, and when they expand, they exert expansion force on a large area of ​​the pressure plate, while the pressure sensor and the pressure plate are connected at a single point with a small contact area, so the expansion force of the battery cannot be accurately fed back to the pressure sensor; (2) The battery and the pressure sensor are separated by the pressure plate, which is usually made of hard material, so some of the expansion force is dissipated by the pressure plate during the expansion process, resulting in errors; (3) The detection function is limited. Specifically, this method can only detect changes in expansion force under charging and discharging conditions, and cannot be used to detect changes in battery parameters under different conditions such as constant pressure, holding pressure, and variable pressure. Summary of the Invention

[0004] The main objective of this invention is to provide a solid-state battery cycle expansion performance testing system and method, which solves the problems existing in the prior art, enables more accurate battery expansion detection, and also has multiple detection modes.

[0005] To achieve the above objectives, one solution of the present invention is: A solid-state battery cycle expansion performance testing system includes an oil tank, a static pressure vessel, a hydraulic control unit, a charge / discharge instrument, and a main controller. The oil tank stores hydraulic oil. At least one static pressure vessel is provided, comprising a sealed container shell, a battery detection probe, and a first pressure gauge mounted on the container shell. The container shell houses the battery under test and has a first inlet and a first outlet whose opening and closing states are controllable. The inner end of the battery detection probe is electrically connected to the tab of the battery under test. The first pressure gauge detects the liquid pressure inside the container shell. The hydraulic control unit is located between the oil tank and the static pressure vessel, and is used to realize the flow of hydraulic oil between the first inlet and the first outlet of the oil tank and the static pressure vessel. The charge / discharge instrument is electrically connected to the outer end of the battery detection probe. The main controller is electrically connected to the hydraulic control unit and the charge / discharge instrument for control and has a parameter acquisition module.

[0006] The first inlet is located on the bottom surface or side of the container shell near the bottom surface, and the first outlet is located on the top surface of the container shell.

[0007] The hydraulic control unit includes a first servo valve and a first flow meter disposed between the output end of the oil reservoir and the first inlet, and a first servo valve and a first flow meter disposed between the first outlet and the input end of the oil reservoir; a check valve is also disposed between the first flow meter and the first inlet.

[0008] Preferably, the hydraulic control unit includes an oil delivery pump and an oil return pump respectively disposed at the output end and input end of the oil reservoir, for driving the hydraulic oil to flow.

[0009] Preferably, a first solenoid valve, a booster cylinder, and a high-pressure oil tank are sequentially connected between the output end of the oil pump and the first inlet; a return oil tank and a pressure reducing valve are sequentially connected between the first outlet and the input end of the return oil pump; and a second pressure gauge is provided in the high-pressure oil tank.

[0010] Alternatively, the hydraulic control unit may include hydraulic cylinders and a drive device corresponding to the number of hydrostatic containers; the hydraulic cylinder includes a cylinder body and a piston rod dynamically sealed within the cylinder body; the cylinder body is provided with a second inlet and a second outlet, the second inlet being connected to the oil reservoir; the second outlet being connected to the first inlet; the drive device is throttledly connected to the piston rod and is used to drive the piston rod to reciprocate within the cylinder body to draw hydraulic oil into the second inlet and pump it out of the second outlet; a one-way valve is provided at the input end of the first inlet.

[0011] Preferably, a second solenoid valve and a first flow meter are provided between the second outlet and the first inlet. The second solenoid valve is used to control the opening and closing of the pipeline between the second outlet and the first inlet, and the first flow meter is used to detect the flow rate of hydraulic oil flowing into the static pressure vessel. A third solenoid valve and a second flow meter are provided between the first outlet and the oil storage tank. The third solenoid valve is used to control the opening and closing of the pipeline between the first outlet and the oil storage tank, and the second flow meter is used to detect the flow rate of hydraulic oil discharged from the static pressure vessel.

[0012] Preferably, the driving device is a servo motor, and is connected to the piston rod via a lead screw drive.

[0013] The static pressure vessel also includes at least one heating rod disposed on the vessel shell, and a pressure relief valve disposed on the top of the vessel shell; the heating rod is used to heat the hydraulic oil inside the vessel shell; the main controller has a temperature control module for monitoring and controlling the working status of the heating rod.

[0014] The container shell includes a sealed body and a cover; the battery detection probe and the first pressure gauge are both mounted on the cover; a pair of pull rods are vertically connected to both ends of the lower surface of the cover, a support plate is connected between the lower ends of the pull rods, and a fixing clamp can be installed between the two ends of each pull rod; the support plate is used to support the lower surface of the battery under test, and the fixing clamp is used to clamp and fix the upper surface or side of the battery under test.

[0015] The solid-state battery cycle expansion performance testing system also includes an exhaust valve located on top of the oil tank, an insulation shell covering the outside of the static pressure container, and a host computer electrically connected to the main controller.

[0016] The second solution of the present invention is: A method for testing the cycle expansion performance of a solid-state battery, using the aforementioned solid-state battery cycle expansion performance testing system, includes the following steps: Step S1. Open both the first inlet and the first outlet of the hydrostatic container and inject hydraulic oil into the container shell to expel the air inside; Step S2. Heat the container shell to maintain its temperature within a preset temperature range; Step S3. Open the first inlet, close the first outlet, and continue to input hydraulic oil into the container shell until the pressure detected by the first pressure gauge reaches the preset value; Step S4. Start the test according to the preset pressure holding, constant pressure, or variable pressure mode.

[0017] The detection process in step S4 is as follows: S4a. Pressure Holding Mode Once the pressure reaches the preset value, pressurization is stopped to ensure the pressure value stabilizes. The battery charging and discharging function of the charge and discharge instrument is then activated. After the battery expands and contracts, causing changes in the internal pressure of the static pressure container, the charging and discharging performance of the battery is analyzed by monitoring these pressure changes. S4b. Constant voltage mode Once the pressure reaches the preset value, the battery charging and discharging function of the charge and discharge device is activated. After the battery expands and contracts, causing changes in the internal pressure of the static pressure container, the internal pressure of the static pressure container is adjusted in real time by the hydraulic control unit to keep it at the preset value, with pressure fluctuation not exceeding 0.1 MPa; the charging and discharging performance of the battery under the same pressure is monitored. S4c. Transformer Mode The hydraulic control unit is preset with a programmable pressure, maintaining different pressure values ​​at different times. When the battery charging and discharging function of the charge / discharge device is activated, the internal pressure of the static pressure container changes due to the expansion and contraction of the battery. The hydraulic control unit adjusts the internal pressure of the static pressure container in real time to maintain it at different values ​​at different times, with pressure fluctuations not exceeding 0.1 MPa. The charging and discharging performance of the battery under different pressures is monitored.

[0018] After adopting the above technical solution, the present invention has the following technical effects: This invention utilizes a sealed container shell to house the battery under test. The container shell has a first inlet and a first outlet whose opening and closing states are controllable. Under the precise control of a hydraulic control unit, a certain amount of hydraulic oil can be input and output into the container shell, controlling the hydraulic pressure within the static pressure container. During battery testing, the battery under test is fully immersed in the hydraulic oil, making comprehensive and seamless contact with it. The expansion force generated by the battery's expansion is directly reflected in the change in hydraulic pressure, which can then be accurately detected by a first pressure gauge, thus improving testing accuracy. When other types of testing require constant pressure or variable pressure modes, the first inlet and first outlet can be flexibly opened and closed to pressurize or depressurize, flexibly controlling the internal hydraulic pressure changes of the static pressure container to meet various testing needs. When multiple static pressure containers are used, multiple batteries can be tested simultaneously to achieve multi-channel testing. Each channel can be independently pressure-controlled and tested without interference. When replacing a battery, only the corresponding channel needs to be paused; other channels remain unaffected. Attached Figure Description

[0019] Figure 1 This is an overall structural block diagram of the first embodiment of the present invention.

[0020] Figure 2This is an overall perspective view of the first embodiment of the present invention.

[0021] Figure 3 This is a partial perspective view of the first embodiment of the present invention.

[0022] Figure 4 This is an exploded view of the static pressure vessel according to the first embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the hydraulic oil flow direction according to the first embodiment of the present invention.

[0024] Figure 6 This is a partial structural block diagram of the second embodiment of the present invention.

[0025] Figure 7 This is a partial three-dimensional structure of the second embodiment of the present invention. Figure 1 .

[0026] Figure 8 This is a partial three-dimensional structure of the second embodiment of the present invention. Figure 2 .

[0027] Figure 9 This is an exploded view of the static pressure vessel according to the second embodiment of the present invention.

[0028] Explanation of icon numbers: 1-Oil storage tank; 11-Exhaust valve; 2-Static pressure vessel; 21-Container shell; 21a-Body; 21b-Cover; 211-First inlet; 212-First outlet; 22-Battery detection probe; 23-First pressure gauge; 24-Heating rod; 25-Pressure relief valve; 26-Pull rod; 27-Support plate; 28-Fixing clamp; 3-Hydraulic control unit; 31-First servo valve; 32-First flow meter; 33-Second servo valve; 34-Second flow meter; 35-Check valve; 36-Oil pump; 37 - Return oil pump; 38- First solenoid valve; 39- Booster cylinder; 310- High-pressure oil tank; 320- Return oil tank; 330- Pressure reducing valve; 340- Second pressure gauge; 350- Hydraulic cylinder; 3501- Cylinder body; 3502- Piston rod; 3503- Second inlet; 3504- Second outlet; 360- Drive device; 370- Second solenoid valve; 380- Third solenoid valve; 4- Charge / discharge instrument; 5- Main controller; 6- Frame; 7- Insulation shell; 8- Host computer; a- Battery under test; b- Tab. Detailed Implementation

[0029] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0030] refer to Figures 1 to 5As shown, a first embodiment of the present invention is illustrated, a solid-state battery cycle expansion performance testing system, including an oil tank 1, a static pressure container 2, a hydraulic control unit 3, a charge / discharge instrument 4, and a main controller 5; Oil reservoir 1 is used to store hydraulic oil; At least one hydrostatic container 2 is provided, which includes a sealed container shell 21, and a battery detection probe 22 and a first pressure gauge 23 mounted on the container shell 21; the container shell 21 is used to house the battery to be tested a, and is provided with a first inlet 211 and a first outlet 212 whose opening and closing states are controllable; the inner end of the battery detection probe 22 is electrically connected to the tab b of the battery to be tested a; the first pressure gauge 23 is used to detect the liquid pressure inside the container shell 21; The hydraulic control unit 3 is located between the oil storage tank 1 and the static pressure vessel 2, and is used to realize the flow of hydraulic oil between the first inlet 211 and the first outlet 212 of the oil storage tank 1 and the static pressure vessel 2. The charge / discharge device 4 is electrically connected to the outer end of the battery detection probe 22; The main controller 5 is electrically connected to the hydraulic control unit 3 and the charge / discharger 4 to achieve control, and has a parameter acquisition module for acquiring relevant parameters (such as expansion force, voltage, current, etc.) generated during the charging and discharging process of the battery under test a.

[0031] Through the above scheme, the present invention uses a sealed container shell 21 to house the battery under test a, and the container shell 21 has a first inlet 211 and a first outlet 212 whose opening and closing states can be controlled. Under the precise control of the hydraulic control unit 3, a certain amount of hydraulic oil can be input and output into the container shell 21 to control the hydraulic pressure inside the static pressure container 2. During the battery testing process, the battery under test a is fully immersed in the hydraulic oil, making all-round and no dead angle contact with the hydraulic oil. The expansion force generated by its expansion can also be directly reflected as a change in hydraulic pressure, thereby enabling it to be detected by the first... The pressure gauge 23 accurately detects the pressure, thus improving the detection accuracy. When other types of detection are required, such as constant pressure or variable pressure modes, the pressure can be increased or decreased by flexibly opening and closing the first inlet 211 and the first outlet 212. This allows for flexible control of the internal hydraulic pressure changes of the static pressure vessel 2, meeting various detection needs. When multiple static pressure vessels 2 are installed, multiple batteries can be detected simultaneously to achieve multi-channel detection. Each channel can be independently pressure-controlled and detected without interference. When replacing batteries, only the corresponding channel needs to be paused, and other channels remain unaffected.

[0032] The technical details of the first embodiment are shown below.

[0033] In the first embodiment, the first inlet 211 is located on the bottom surface of the container shell 21, and the first outlet 212 is located on the top surface of the container shell 21. Therefore, when oil is introduced into the hydrostatic container 2, the hydraulic oil flows from bottom to top, which can expel air from inside the container shell 21 and reduce interference factors in battery detection.

[0034] In the first embodiment, the hydraulic control unit 3 includes a first servo valve 31 and a first flow meter 32 disposed between the output end of the oil reservoir 1 and the first inlet 211, and a second servo valve 33 and a first flow meter 34 disposed between the first outlet 212 and the input end of the oil reservoir 1. These two servo valves can precisely control the flow direction and flow rate of the hydraulic oil, achieving precise adjustment of the hydraulic pressure within the hydrostatic container 2; while the two flow meters are used to monitor the flow rate of the hydraulic oil, measuring the flow rate of hydraulic oil flowing into and out of the container shell 21 respectively, ensuring the accuracy of flow control.

[0035] Furthermore, a check valve 35 is provided between the first flow meter 32 and the first inlet 211 to prevent hydraulic oil backflow.

[0036] In the first embodiment, the hydraulic control unit 3 includes an oil pump 36 and an oil return pump 37 respectively disposed at the output end and input end of the oil storage tank 1, for driving the hydraulic oil to flow.

[0037] Furthermore, a first solenoid valve 38, a booster cylinder 39, and a high-pressure oil tank 310 are sequentially connected between the output end of the aforementioned oil pump 36 and the first inlet 211; a return oil tank 320 and a pressure reducing valve 330 are sequentially connected between the first outlet 212 and the input end of the return oil pump 37. The aforementioned high-pressure oil tank 310 is equipped with a second pressure gauge 340. This allows for minute and precise pressure control, ensuring long-term pressure stability.

[0038] The aforementioned static pressure vessel 2 also includes at least one heating rod 24 disposed on the vessel shell 21. The heating rod 24 is used to heat the hydraulic oil inside the vessel shell 21 to provide a temperature environment that meets the testing requirements. The main controller 5 has a temperature control module for monitoring and controlling the working status of the heating rod 24. The heating rod 24 is preferably disposed at the bottom of the vessel shell 21.

[0039] The aforementioned static pressure vessel 2 also includes a pressure relief valve 25 disposed on the top of the vessel shell 21. When the internal pressure of the static pressure vessel 2 exceeds a preset value or other conditions require pressure relief, the pressure relief valve 25 can be automatically or manually opened to relieve pressure, depending on the type of pressure relief valve 25.

[0040] The aforementioned container shell 21 includes a sealed body 21a and a cover 21b. The battery testing probe 22, the first pressure gauge 23, and the pressure relief valve 25 are all mounted on the cover 21b. A pair of pull rods 26 are vertically connected to both ends of the lower surface of the cover 21b. A support plate 27 is connected between the lower ends of the pull rods 26, and a fixing clip 28 can be installed between the two ends of each pull rod 26 in a lifting manner. The support plate 27 supports the lower surface of the battery a under test, and the fixing clip 28 clamps and fixes the side of the battery a under test, such as clamping it onto the thin film jacket of the battery a under test. This provides a limiting effect on the battery a under test, preventing it from violently shaking inside the container shell 21 during testing. The contact surface between the body 21a and the cover 21b can be sealed using a sealing ring or similar method and locked with several bolts, ensuring the connection strength between the cover 21b and the body 21a and meeting the high-pressure requirements of the container shell 21 during testing.

[0041] The present invention also includes an exhaust valve 11 disposed on the top of the oil reservoir 1. When the exhaust valve 11 is opened, it can be used to discharge the gas in the oil reservoir 1 to ensure that the hydraulic oil can flow smoothly.

[0042] The present invention also includes a frame 6, a plurality of static pressure vessels 2 are arranged at equal intervals on the front side of the upper surface of the frame 6, and an oil storage tank 1 is disposed inside the frame 6.

[0043] The present invention also includes an insulating outer shell 7 covering the outside of the static pressure container 2, which can reduce heat loss from the static pressure container 2 and maintain the temperature environment required for detection.

[0044] The present invention also includes a host computer 8 electrically connected to the main controller 5, which is used to realize human-computer interaction and facilitate operations such as viewing detection data and adjusting parameters.

[0045] refer to Figures 6 to 9 The diagram illustrates a second embodiment of the present invention, which is also a solid-state battery cycle expansion performance testing system. Its main difference from the first embodiment is that: The hydraulic control unit 3 of the second embodiment includes hydraulic cylinders 350 and a drive device 360 ​​corresponding to the number of static pressure vessels 2. The hydraulic cylinder 350 includes a cylinder body 3501 and a piston rod 3502 dynamically sealed within the cylinder body 3501. The cylinder body 3501 is provided with a second inlet 3503 and a second outlet 3504. The second inlet 3503 is connected to the oil storage tank 1, and the second outlet 3504 is connected to the first inlet 211. The drive device 360 ​​is driven by the piston rod 3502 and is used to drive the piston rod 3502 to reciprocate within the cylinder body 3501 according to a preset frequency and stroke, so as to draw hydraulic oil into the second inlet 3503 and pump it out of the second outlet 3504. Thus, in the second embodiment, by driving the piston rod 3502 through the drive device 360, hydraulic oil from the oil storage tank 1 can be pumped into the static pressure vessel 2 according to a preset frequency and stroke. By adjusting the number of strokes and the stroke range of the piston rod 3502, a certain amount of hydraulic oil can be precisely pumped in, thereby controlling the hydraulic pressure within the static pressure vessel 2.

[0046] The input end of the first inlet 211 is equipped with a check valve 35 to prevent hydraulic oil from flowing back to the hydraulic cylinder 350.

[0047] A second solenoid valve 370 and a first flow meter 32 are provided between the second outlet 3504 and the first inlet 211. The second solenoid valve 370 is used to control the opening and closing of the pipeline between the second outlet 3504 and the first inlet 211, that is, to control the opening and closing of the first inlet 211. The first flow meter 32 can detect the flow rate of hydraulic oil flowing into the static pressure vessel 2. A third solenoid valve 380 and a second flow meter 34 are provided between the first outlet 212 and the oil storage tank 1. The third solenoid valve 380 is used to control the opening and closing of the pipeline between the first outlet 212 and the oil storage tank 1, that is, to control the opening and closing of the first outlet 212. The second flow meter 34 can detect the flow rate of hydraulic oil discharged from the static pressure vessel 2.

[0048] The second inlet 3503 is located on the side of the container housing 21 near its bottom, and the second outlet 3504 is located on the top surface of the container housing 21. Therefore, when oil is introduced into the hydrostatic container 2, the hydraulic oil flows from bottom to top, which can expel air from inside the container housing 21 and reduce interference factors in battery detection.

[0049] Similar to the first embodiment, the oil storage tank 1 is equipped with an exhaust valve 11 and a return oil pump 37. When the exhaust valve 11 is opened, it can be used to discharge the gas in the oil storage tank 1 to ensure that the hydraulic oil can flow smoothly. The return oil pump 37 is connected to the first outlet 212 through a pipeline (the third solenoid valve 380 and the second flow meter 34 may also be provided between the two) to provide the power for the hydraulic oil to flow back to the oil storage tank 1.

[0050] The aforementioned drive device 360 ​​is a servo motor, which is connected to the piston rod 3502 via a lead screw drive. By employing a servo motor, its high precision, high speed, and high reliability can be utilized to programmatically control the reciprocating motion of the piston rod 3502 according to a preset frequency and stroke, thereby precisely controlling the pumping and discharging of hydraulic oil to meet the requirements of battery expansion detection.

[0051] The static pressure container 2 of the second embodiment is basically the same as that of the first embodiment, except that in the second embodiment, the fixing clip 28 is clamped on the upper surface of the battery a to be tested.

[0052] Furthermore, a third embodiment of the present invention is shown below, a method for testing the cycle expansion performance of a solid-state battery, which uses the above-described solid-state battery cycle expansion performance testing system and includes the following steps: Step S1. Open the first inlet 211 and the first outlet 212 of the static pressure vessel 2, and input hydraulic oil into the vessel shell 21 to expel the air inside. Step S2. Heat the container shell 21 to maintain its temperature within a preset temperature range; Step S3. Open the first inlet 211, close the first outlet 212, and continue to input hydraulic oil into the container shell 21 until the pressure detected by the first pressure gauge 23 reaches the preset value; Step S4. Start the test according to the preset pressure holding, constant pressure, or variable pressure mode.

[0053] Specifically, the detailed testing process is as follows: S4a. Pressure Holding Mode Once the pressure reaches the preset value, pressurization is stopped to ensure the pressure value is stable. The battery charging and discharging function of the charge / discharge instrument 4 is turned on. After the battery expands and contracts, causing changes in the internal pressure of the static pressure container 2, the charging and discharging performance of the battery is analyzed by monitoring these pressure changes.

[0054] S4b. Constant voltage mode Once the pressure reaches the preset value, the battery charging and discharging function of the charge / discharger 4 is activated. After the battery expands and contracts, causing changes in the internal pressure of the static pressure container 2, the internal pressure of the static pressure container 2 is adjusted in real time by the hydraulic control unit 3 to keep it at the preset value, with pressure fluctuations not exceeding 0.1 MPa; the changes in the charging and discharging performance of the battery under the same pressure are monitored.

[0055] S4c. Transformer Mode The hydraulic control unit 3 is preset with programmable pressure, such as 1 MPa for 24 hours, 1.5 MPa for 24 hours, etc. When the battery charging and discharging function of the charge and discharge instrument 4 is turned on, the internal pressure of the static pressure container 2 changes due to the expansion and contraction of the battery. The hydraulic control unit 3 adjusts the internal pressure of the static pressure container 2 in real time so that it is maintained at different values ​​at different times, and the pressure fluctuation does not exceed 0.1 MPa. The charging and discharging performance of the battery under different pressures is monitored.

[0056] The above embodiments and figures are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A solid-state battery cycle expansion performance testing system, characterized in that: Includes an oil reservoir, a static pressure vessel, a hydraulic control unit, a charge / discharge device, and a main controller; The oil storage tank is used to store hydraulic oil; At least one hydrostatic container is provided, which includes a sealed container shell, a battery detection probe and a first pressure gauge mounted on the container shell; the container shell is used to house the battery to be tested and is provided with a first inlet and a first outlet whose opening and closing states are controllable; the inner end of the battery detection probe is electrically connected to the tab of the battery to be tested; the first pressure gauge is used to detect the liquid pressure inside the container shell; The hydraulic control unit is located between the oil reservoir and the static pressure vessel, and is used to realize the flow of hydraulic oil between the first inlet and the first outlet of the oil reservoir and the static pressure vessel; The charge / discharge device is electrically connected to the outer end of the battery detection probe; The main controller is electrically connected to the hydraulic control unit and the charge / discharge device to achieve control, and has a parameter acquisition module.

2. The solid-state battery cycle expansion performance testing system as described in claim 1, characterized in that: The first inlet is located on the bottom surface or side of the container shell near the bottom surface, and the first outlet is located on the top surface of the container shell.

3. The solid-state battery cycle expansion performance testing system as described in claim 1, characterized in that: The hydraulic control unit includes a first servo valve and a first flow meter disposed between the output end of the oil reservoir and the first inlet, and a first servo valve and a first flow meter disposed between the first outlet and the input end of the oil reservoir; a check valve is also disposed between the first flow meter and the first inlet.

4. The solid-state battery cycle expansion performance testing system as described in claim 3, characterized in that: The hydraulic control unit includes an oil delivery pump and an oil return pump respectively installed at the output end and input end of the oil reservoir, used to drive the hydraulic oil to flow.

5. The solid-state battery cycle expansion performance testing system as described in claim 4, characterized in that: A first solenoid valve, a booster cylinder, and a high-pressure oil tank are sequentially connected between the output end of the oil pump and the first inlet; a return oil tank and a pressure reducing valve are sequentially connected between the first outlet and the input end of the return oil pump; and a second pressure gauge is installed in the high-pressure oil tank.

6. The solid-state battery cycle expansion performance testing system as described in claim 1, characterized in that: The hydraulic control unit includes hydraulic cylinders and a drive device corresponding to the number of hydrostatic containers; the hydraulic cylinder includes a cylinder body and a piston rod dynamically sealed within the cylinder body; the cylinder body is provided with a second inlet and a second outlet, the second inlet being connected to the oil reservoir; the second outlet being connected to the first inlet; the drive device is throttledly connected to the piston rod and is used to drive the piston rod to reciprocate within the cylinder body to draw hydraulic oil into the second inlet and pump it out of the second outlet; a one-way valve is provided at the input end of the first inlet.

7. The solid-state battery cycle expansion performance testing system as described in claim 6, characterized in that: A second solenoid valve and a first flow meter are provided between the second outlet and the first inlet. The second solenoid valve is used to control the opening and closing of the pipeline between the second outlet and the first inlet, and the first flow meter is used to detect the flow rate of hydraulic oil flowing into the static pressure vessel. A third solenoid valve and a second flow meter are provided between the first outlet and the oil storage tank. The third solenoid valve is used to control the opening and closing of the pipeline between the first outlet and the oil storage tank, and the second flow meter is used to detect the flow rate of hydraulic oil discharged from the static pressure vessel.

8. The solid-state battery cycle expansion performance testing system as described in claim 6, characterized in that: The driving device is a servo motor, which is connected to the piston rod via a lead screw drive.

9. The solid-state battery cycle expansion performance testing system as described in claim 1, characterized in that: The static pressure vessel also includes at least one heating rod disposed on the vessel shell, and a pressure relief valve disposed on the top of the vessel shell; the heating rod is used to heat the hydraulic oil inside the vessel shell; the main controller has a temperature control module for monitoring and controlling the working status of the heating rod.

10. The solid-state battery cycle expansion performance testing system as described in claim 1, characterized in that: The container shell includes a sealed body and a cover; the battery detection probe and the first pressure gauge are both mounted on the cover; a pair of pull rods are vertically connected to both ends of the lower surface of the cover, a support plate is connected between the lower ends of the pull rods, and a fixing clamp can be installed between the two ends of each pull rod; the support plate is used to support the lower surface of the battery under test, and the fixing clamp is used to clamp and fix the upper surface or side of the battery under test.

11. The solid-state battery cycle expansion performance testing system as described in claim 1, characterized in that: It also includes an exhaust valve located on top of the oil storage tank, an insulation shell covering the outside of the static pressure vessel, and a host computer electrically connected to the main controller.

12. A method for testing the cycle expansion performance of a solid-state battery, using the solid-state battery cycle expansion performance testing system as described in any one of claims 1 to 11, characterized in that... Includes the following steps: Step S1. Open both the first inlet and the first outlet of the hydrostatic container and inject hydraulic oil into the container shell to expel the air inside; Step S2. Heat the container shell to maintain its temperature within a preset temperature range; Step S3. Open the first inlet, close the first outlet, and continue to input hydraulic oil into the container shell until the pressure detected by the first pressure gauge reaches the preset value; Step S4. Start the test according to the preset pressure holding, constant pressure, or variable pressure mode.

13. The method for testing the cycle expansion performance of a solid-state battery as described in claim 12, characterized in that... The detection process in step S4 is as follows: S4a. Pressure Holding Mode Once the pressure reaches the preset value, pressurization is stopped to ensure the pressure value stabilizes. The battery charging and discharging function of the charge and discharge instrument is then activated. After the battery expands and contracts, causing changes in the internal pressure of the static pressure container, the charging and discharging performance of the battery is analyzed by monitoring these pressure changes. S4b. Constant voltage mode Once the pressure reaches the preset value, the battery charging and discharging function of the charge and discharge device is activated. After the battery expands and contracts, causing changes in the internal pressure of the static pressure container, the internal pressure of the static pressure container is adjusted in real time by the hydraulic control unit to keep it at the preset value, with pressure fluctuation not exceeding 0.1 MPa; the charging and discharging performance of the battery under the same pressure is monitored. S4c. Transformer Mode The hydraulic control unit is preset with a programmable pressure, maintaining different pressure values ​​at different times. When the battery charging and discharging function of the charge / discharge device is activated, the internal pressure of the static pressure container changes due to the expansion and contraction of the battery. The hydraulic control unit adjusts the internal pressure of the static pressure container in real time to maintain it at different values ​​at different times, with pressure fluctuations not exceeding 0.1 MPa. The charging and discharging performance of the battery under different pressures is monitored.

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