Battery cycle aging test device, combined tool and test method under various constraints

Abstract

The invention provides a battery cycle aging test device, a combined tool and a test method under various constraints. The battery cyclic aging test device under various constraints comprises a flat plate assembly, the flat plate assembly comprises a top plate, an upper pressing plate and a lower pressing plate which are sequentially arranged in parallel from top to bottom, and the upper pressing plate and the lower pressing plate can jointly clamp a battery; the connecting column assembly comprises a guide column connected with the flat plate assembly, and the upper pressing plate and the lower pressing plate have the linear lifting freedom degree along the guide column; the sensor assembly comprises a displacement sensor and a load sensor, the displacement sensor is assembled with the top plate, and a probe of the displacement sensor is in contact with the upper surface of the upper pressing plate; and the bottom plate is fixed with the bottom ends of the guide columns, and the load sensor is clamped by the lower pressing plate and the bottom plate together. And performing an aging test on the battery under an expected constraint condition. Meanwhile, expansion displacement and expansion force signals can be output in real time, and experimental data support is conveniently provided for battery full-life-cycle model development.

Description

Technical Field

[0001] The present application relates to the field of battery testing, and in particular to a battery cycle aging testing device, combined tooling and testing method under multiple constraints. Background Art

[0002] In recent years, the number of new energy vehicles has increased rapidly. As the main energy supply component of new energy vehicles, the use of lithium-ion power batteries has also increased. However, lithium-ion batteries inevitably have the problem of life attenuation, which leads to a decrease in the range of new energy vehicles or a decrease in discharge efficiency. More seriously, it can cause the battery to swell violently and fail, bringing the risk of thermal runaway. Therefore, before lithium-ion batteries are put into use, they must be subjected to detailed cycle aging tests. However, most current studies focus on the effects of charge and discharge rates and temperature on cycle aging, and there are fewer studies under different load constraints.

[0003] In the actual use of lithium-ion batteries, a single battery is generally placed in a battery module or battery pack, and both sides of the battery are constrained by other structures. For example, mica sheets, foam structures, circular frames or other batteries, etc. Different grouping structures will give different load constraints to the battery. However, in actual vehicles, the layout of expansion signal sensors is far more difficult than temperature sensors, which will also increase the difficulty of load constraint impact analysis. As relevant studies have proved that constraints have a greater impact on battery cycle aging, various research teams and manufacturers have begun to pay attention to the study of batteries under constraints.

[0004] Considering that it is difficult to directly place stress sensors and expansion displacement sensors in the battery pack of new energy vehicles, and the stability is poor, most current studies mainly test the battery aging performance and related expansion behavior under load constraints in a laboratory environment. Most models rely only on empirical fitting of parameters related to the initial working conditions. This leads to unclear life attenuation mechanisms and expansion evolution mechanisms of batteries under constraints, which is not conducive to the construction of high-precision mechanism models under the full life cycle behavior of batteries.

[0005] The Chinese invention patent with the announcement number "CN110109026B" discloses "device and method for measuring expansion force and displacement components during charging and discharging of lithium batteries". The measuring device includes a lithium battery testing device for detecting the expansion force and displacement signals of lithium batteries during charging and discharging at different temperatures, currents and voltages. However, the displacement sensor and the weighing sensor of the measuring device are arranged on the same side of the battery. From a feasible perspective, the displacement sensor and the weighing sensor are generally arranged at the same time. Therefore, there is still room for improvement in the simultaneous, real-time and accurate detection of battery expansion signals. Summary of the invention

[0006] This application is made in view of the above-mentioned state of the prior art. This application aims to solve or alleviate at least one of the above-mentioned problems.

[0007] In the first aspect, the present application provides a battery aging detection device under multiple constraints, including: a flat plate assembly, the flat plate assembly includes a top plate, an upper pressure plate, and a lower pressure plate arranged in parallel from top to bottom, and the upper pressure plate and the lower pressure plate can clamp the battery together; a connecting column assembly, the connecting column assembly includes a guide column connected to the flat plate assembly, and the upper pressure plate and the lower pressure plate have a linear lifting freedom along the guide column; a sensor assembly, the sensor assembly includes a displacement sensor and a load sensor, the displacement sensor is assembled with the top plate, and the probe of the displacement sensor is in contact with the upper surface of the upper pressure plate; and a bottom plate, the bottom plate is fixed to the bottom end of the guide column, and the load sensor is clamped by the lower pressure plate and the bottom plate.

[0008] As a further improvement of the present application, the connecting column assembly also includes a vertical column arranged parallel to the guide column, the bottom end of the vertical column is fixed to the bottom plate, and the top end of the vertical column is movably assembled with the top plate; the top end of the vertical column is provided with an upper threaded section passing through the top plate, and the upper threaded section is movably assembled with a nut, and the nut is in contact with the upper surface of the top plate; the vertical column is also provided with a compression spring, and the two ends of the compression spring are respectively in contact with the top plate and the upper pressure plate.

[0009] As a further improvement of the present application, the bottom end of the vertical column has a lower threaded section for threaded assembly with the base plate; the bottom end of the guide column has a bottom threaded section for threaded assembly with the base plate; the vertical column between the upper threaded section and the lower threaded section is the optical axis, the part between the bottom threaded section and the upper end of the guide column is the optical axis, and the optical axis is a cylinder; the compression spring has several replacement specifications of different shapes, sizes and / or materials.

[0010] As a further improvement of the present application, a plurality of the guide pillars are symmetrically distributed on both sides of the battery aging detection device under multiple constraints, and a plurality of the vertical pillars are symmetrically distributed on both sides of the battery aging detection device under multiple constraints.

[0011] As a further improvement of the present application, a guide sleeve is movably mounted on the guide column, the upper pressure plate and the lower pressure plate are both fixed to the guide sleeve, and the guide sleeve has a flange portion mounted to the upper pressure plate or the lower pressure plate.

[0012] As a further improvement of the present application, the upper pressing plate and the lower pressing plate each have a boss extending toward each other, and the bosses of the upper pressing plate and the lower pressing plate can jointly clamp the battery.

[0013] In a second aspect, a combination tooling for constraining batteries is provided, including: a free expansion tooling, wherein the free expansion tooling includes a top plate, an upper pressure plate, and a lower pressure plate arranged in parallel from top to bottom; the top plate and the lower pressure plate are connected by guide columns, and the upper pressure plate has the freedom to rise and fall in a straight line along the guide columns; the upper pressure plate and the lower pressure plate in the free expansion tooling can clamp the battery together.

[0014] As a further improvement of the present application, the combined tooling of the battery under multiple constraints also includes: a constant boundary tooling, the constant boundary tooling includes an upper pressure plate, a lower pressure plate, and a bottom plate arranged in parallel from top to bottom; the upper pressure plate and the bottom plate are connected by a vertical column, and the lower pressure plate has the freedom of linear lifting and lowering along the vertical column; the top of the vertical column has an upper threaded section that passes through the upper pressure plate, and the upper threaded section is movably equipped with a nut, and the nut is in contact with the upper surface of the upper pressure plate; the upper pressure plate and the lower pressure plate in the constant boundary tooling can clamp the battery together. As a further improvement of the present application, the top plate in the free expansion tooling is equipped with a displacement sensor, and the probe of the displacement sensor is in contact with the upper surface of the upper pressure plate; the lower pressure plate and the bottom plate in the constant boundary tooling are clamped together with a load sensor.

[0015] According to a third aspect, a battery aging detection method under multiple constraints is provided, comprising: step S1: pressurizing the top plate using a compression testing machine; wherein, when the mechanical value of the compression testing machine reaches a predetermined value, keeping the compression testing machine stationary, and starting to screw the nut; when the mechanical value of the compression testing machine returns to zero, loading is completed; step S2: assembling the displacement sensor onto the top plate, connecting the displacement signal of the displacement sensor, and the force signal of the load sensor; connecting the charging line to the positive and negative poles of the battery, and starting a cyclic aging experiment according to a predetermined charging current or discharge current.

[0016] The beneficial effects of the battery aging detection device under multiple constraints of the present application include: providing a detection device to enable the battery to be aged under the expected constraint conditions. At the same time, it can output the expansion displacement and expansion force signals in real time, which is convenient for providing experimental data support for the development of the battery life cycle model. When the battery expands, the expansion amount (i.e., expansion displacement) is transmitted to the displacement sensor through the upper pressure plate, and the expansion force is transmitted to the load sensor through the lower pressure plate. In this way, the expansion displacement and expansion force of the battery during the cyclic aging process can be obtained in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is an exploded diagram of an implementation of a battery aging detection device under multiple constraints of the present application;

[0019] Figure 2 is a rear view of an embodiment of a battery aging detection device under various constraints of the present application;

[0020] Figure 3 is a top view of an implementation of a battery aging detection device under multiple constraints of the present application;

[0021] Figure 4 It is a right view of an implementation of a battery aging detection device under multiple constraints of the present application;

[0022] Figure 5 yes Figure 4 AA cross-sectional view of a battery aging detection device under various constraints;

[0023] Figure 6 It is a three-dimensional diagram of a constant boundary fixture of one embodiment of a combined fixture of batteries under multiple constraints of the present application;

[0024] Figure 7 It is a three-dimensional view of a free expansion tooling of one embodiment of a combined tooling of batteries under various constraints of the present application.

[0025] Description of Reference Numerals

[0026] 1-top plate; 2-bottom plate; 21-step hole; 3-vertical column; 31-upper threaded section; 32-lower threaded end; 4-nut; 5-compression spring; 6-guide column; 61-milled flat section; 62-bottom threaded section; 7-upper pressure plate; 71-lower boss; 8-lower pressure plate; 81-upper boss; 9-displacement sensor; 91-probe; 10-battery; 11-load sensor; 12-upper guide sleeve; 13-lower guide sleeve. DETAILED DESCRIPTION

[0027] The exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0028] In the following, in conjunction with specific embodiments, the battery cycle aging test device under multiple constraints, the battery combination tooling under multiple constraints, and the battery cycle aging test method under multiple constraints of the present application are further described in detail.

[0029] See also Figure 1 The battery aging detection device under multiple constraints of the present application includes a flat plate assembly, a connecting column assembly, and a sensor assembly. Among them, the flat plate assembly includes a top plate 1, an upper pressure plate 7, and a lower pressure plate 8 arranged in sequence from top to bottom. The upper pressure plate 7 and the lower pressure plate 8 can clamp the battery 10 together. The connecting column assembly includes a guide column 6 connecting the flat plate assembly, and the upper pressure plate 7 and the lower pressure plate 8 have the freedom of linear lifting along the guide column 6. The sensor assembly includes a displacement sensor 9 and a load sensor 11. The displacement sensor 9 is assembled with the top plate 1, and the probe 91 of the displacement sensor 9 is in contact with the upper surface of the upper pressure plate 7. The load sensor 11 is in contact with the lower surface of the lower pressure plate 8. Cyclic aging refers to the continuous charge and discharge experiment of the battery 10.

[0030] In one embodiment, the plate assembly further includes a bottom plate 2 , the bottom plate 2 is fixed to the bottom end of the guide column 6 , and the load sensor 11 is located on the upper surface of the bottom plate 2 .

[0031] Adding the bottom plate 2 makes the entire battery aging detection device under multiple constraints more complete, and is not affected by the actual ground and work surface during the test.

[0032] In one embodiment, the connecting column assembly further includes a vertical column 3 arranged in parallel with the guide column 6, the bottom end of the vertical column 3 is fixed to the bottom plate 2, and the top end of the vertical column 3 is movably assembled with the top plate 1. The top end of the vertical column 3 is provided with an upper threaded section 31 penetrating the top plate 1, the axial length of the upper threaded section 31 is greater than the thickness of the top plate 1, and the upper threaded section 31 is movably assembled with a nut 4, which contacts the upper surface of the top plate 1. The vertical column 3 is also sleeved with a compression spring 5, and the two ends of the compression spring 5 are in contact with the top plate 1 and the upper pressure plate 7 respectively.

[0033] The compression spring 5 is to ensure that the upper pressure plate 7 always has the elastic potential energy to move downward, and to ensure that the upper pressure plate 7 and the lower pressure plate 8 clamp the battery 10 without gaps. The compression spring 5 can have a variety of models and specifications, and is replaceable. Among them, different models and specifications include but are not limited to different materials, different shaft lengths, different diameters, different compression ratios, different spiral directions, different numbers of turns, etc. Compression springs 5 ​​of different models and specifications can therefore impose a variety of different constraints on the upper pressure plate 7. When the compression spring 5 needs to be replaced, it is achieved by disassembling the nut 4 and the top plate 1 in turn.

[0034] In one embodiment, the bottom end of the vertical column 3 is provided with a lower thread section 32 for threaded assembly with the bottom plate 2. The bottom end of the guide column 6 is provided with a bottom thread section 62 for threaded assembly with the bottom plate 2, and the top end of the guide column 6 is provided with a milled flat section 61. The vertical column 3 between the upper thread section 31 and the lower thread section 32 is an optical axis, and the guide column 6 between the milled flat section 61 and the bottom thread section 62 is also an optical axis, and the optical axis is a cylinder.

[0035] The optical axis of the cylinder can reduce friction and facilitate the vertical movement of the upper pressing plate 7 and the lower pressing plate 8. The milling flat section 61 has the effect of destroying the complete rounded outer contour of the cylinder, which is convenient for contact with disassembly tools such as wrenches, thereby facilitating the disassembly of the guide column 6 and the bottom plate 1.

[0036] In one embodiment, if Figure 1 or Figure 3 As shown, a plurality of guide columns 6 are symmetrically distributed on both sides of the battery 10 , and a plurality of vertical columns 3 are symmetrically distributed on both sides of the battery 10 .

[0037] In a non-limiting example, there are four guide pillars 6 and four vertical pillars 3 , which are symmetrically distributed on both sides of the battery 10 , that is, two guide pillars 6 and two vertical pillars 3 are provided on the same side of the battery 10 .

[0038] In one embodiment, if Figure 1 or Figure 4 As shown, a guide sleeve is movably mounted on the guide column 6, and the upper pressing plate 7 and the lower pressing plate 8 are both fixed to the guide sleeve.

[0039] The upper pressing plate 7 is fixed with an upper guide sleeve 12, and the lower pressing plate 8 is fixed with a lower guide sleeve 13. The upper guide sleeve 12 and the lower guide sleeve 13 both include an integrated circular tube portion and a flange portion, the circular tube portion is coaxially arranged with the guide column 6, and the flange portion of the upper guide sleeve 12 is fixed in surface contact with the upper pressing plate 7, and the flange portion of the lower guide sleeve 13 is fixed in surface contact with the lower pressing plate 8. In addition, the flange portions are fixed to the lower surface of the upper pressing plate 7 or the lower pressing plate 8. After the upper guide sleeve 12 is installed on the upper pressing plate 7, the relative position relationship between the upper guide sleeve 12 and the upper pressing plate 7 remains stable, and after the lower guide sleeve 13 is installed on the lower pressing plate 8, the relative position relationship between the lower guide sleeve 13 and the lower pressing plate 8 remains stable. Both the upper guide sleeve 12 and the lower guide sleeve 13 play a linear guiding role.

[0040] In one embodiment, the upper pressing plate 7 and the lower pressing plate 8 each have bosses extending toward each other, and the bosses of the upper pressing plate 7 and the lower pressing plate 8 can clamp the battery 10 together.

[0041] like Figure 1As shown, the lower surface of the upper pressing plate 7 is provided with a lower boss 71 extending downwardly, and the upper surface of the lower pressing plate 8 is provided with an upper boss 81 extending upwardly. The lower boss 71 and the upper boss 81 can be cavities with a concave and convex fit with the battery 10, that is, the lower boss 71 and the upper boss 81 play a limiting effect on the battery 10, ensuring that the battery 10 is placed in a unique position. The lower boss 71 and the upper boss 81 can firstly limit the placement position of the battery 10, and secondly, the lower boss 71 and the upper boss 81 are equivalent to increasing the interval between the upper pressing plate 7 and the lower pressing plate 8, so that sufficient operating space is left in the vertical direction, so as to facilitate the connection of the pole ear of the battery 10 and facilitate power supply.

[0042] In one embodiment, the probe 91 of the displacement sensor 9 extends vertically downward, and the centroids of the probe 91, the load sensor 11, and the battery 10 are located on the same vertical line in space.

[0043] The top plate 1 may be provided with a hole for the probe 91 to pass through, and the main body of the displacement sensor 9 is located above the top plate 1 .

[0044] The battery aging detection device under multiple constraints of the present application has a simple and ingenious structure, and can provide an approximately constant load during the entire cycle aging process of the battery 10, facilitating subsequent quantitative analysis. It can monitor the expansion amount and expansion force in real time, and output them synchronously with the voltage and capacity signals of the battery 10. It provides an excellent verification data set for the expansion model verification of the battery 10.

[0045] The battery aging detection device under various constraints of the present application is described by taking a small soft-pack battery 10 as an example. If the test object is a large square shell battery, the size of the detection device can be increased accordingly.

[0046] Figures 1 to 5 The battery aging detection device under various constraints is shown. The top plate 1 and the bottom plate 2 are connected by four vertical columns 3, and the distance between them is controlled to be constant by four nuts 4. A displacement sensor 9 is fixed on the top plate 1, and the displacement data measured by it is the displacement data of the upper pressure plate 7. A load sensor 11 is fixed on the bottom plate 2, and its measured data is the internal load of the entire device. Figure 1 and Figure 5As shown, the bottom plate 2 is provided with a plurality of step holes 21, through which fasteners can pass, so as to facilitate fixing the bottom plate 2 to the back of the load sensor 11, so that during the test phase, the relative position relationship between the load sensor 11 and the bottom plate 2 can remain stable. The battery 10 is located between the upper pressing plate 7 and the lower pressing plate 8, and both plates can slide vertically. When the battery 10 expands, the expansion amount is transmitted to the displacement sensor 9 through the upper pressing plate 7, and the expansion force is transmitted to the load sensor 11 through the lower pressing plate 8. In this way, the expansion amount and expansion force of the battery 10 during the cyclic aging process can be obtained in real time. The unit of expansion displacement can be um, and the unit of expansion force can be N.

[0047] Regarding battery aging detection under multiple constraints, the constraints can be divided into initial load and expansion constraint stiffness. The initial load can be adjusted by four nuts 4. The larger the rotation of the nut 4 knob, the higher the initial load. The expansion constraint stiffness is controlled by four compression springs 5. If nonlinear expansion constraint stiffness is required during research, elasticity can be replaced by nonlinear materials. In the same way, different constraints can be obtained. The experimenter can adjust the nut 4 to obtain the expected initial preload. After the experiment starts, the role of the nut 4 is only an assembly constraint.

[0048] Different compression springs 5 ​​can be used according to different target forces. In the initial stage of the test, the compression amount of the compression spring 5 is basically the same, such as 0.05MPa, 0.2MPa, 1MPa, etc.

[0049] In addition, the upper pressure plate 7 can be made of aluminum, with a total weight of no more than 100g, corresponding to 1N. However, the actual expansion force of the vehicle battery is approximately thousands of N or even tens of thousands of N. The lowest expansion force in this study is about 200N, and most of the expansion forces are thousands of N. Therefore, the weight of the upper pressure plate 7 has little effect on the experimental data.

[0050] like Figure 7 As shown, the present application also provides a combination of tools for batteries under various constraints. It includes a free expansion tool. The free expansion tool includes a top plate 1, an upper pressure plate 7, and a lower pressure plate 8 arranged in parallel from top to bottom. The top plate 1 and the lower pressure plate 8 are connected by a guide column 6, and the upper pressure plate 7 has the freedom to rise and fall in a straight line along the guide column 6. The upper pressure plate 7 and the lower pressure plate 8 in the free expansion tool can clamp the battery 10 together. The top plate 1 in the free expansion tool is equipped with a displacement sensor 9, and the probe 91 of the displacement sensor 9 is in contact with the upper surface of the upper pressure plate 7. The free expansion tool can be used to detect the expansion displacement of the battery 10.

[0051] like Figure 6As shown, the combined tooling for batteries under multiple constraints also includes a constant boundary tooling. The constant boundary tooling includes an upper pressure plate 7, a lower pressure plate 8, and a bottom plate 2 arranged in parallel from top to bottom; the upper pressure plate 7 and the bottom plate 2 are connected by a vertical column 3, and the lower pressure plate 8 has the freedom of linear lifting along the vertical column 3. The top of the vertical column 3 is provided with an upper threaded section 31 that passes through the upper pressure plate 7, and the upper threaded section 31 is movably equipped with a nut 4, which contacts the upper surface of the upper pressure plate 7. The upper pressure plate 7 and the lower pressure plate 8 in the constant boundary tooling can clamp the battery 10 together. The lower pressure plate 8 and the bottom plate 2 in the constant boundary tooling clamp a load sensor 11 together. The constant boundary tooling can be used to detect the expansion force of the battery 10.

[0052] See also Figure 6 , Figure 7 and Figure 1 The free expansion fixture and the constant boundary fixture can be combined into a two-in-one structure after being disassembled and then reassembled. Figures 1 to 5 The battery aging detection device under various constraints is shown in FIG. After being disassembled and then reassembled, the battery aging detection device under various constraints can be configured as follows: Figure 7 Free expansion fittings as shown or Figure 6 The constant boundary fixture shown. For example, when there are different detection needs, the battery aging detection device under various constraints can be disassembled and then assembled into any one of the free expansion fixture and the constant boundary fixture. Among them, the free expansion fixture and the constant boundary fixture each have certain common parts.

[0053] In order to facilitate the construction of the constant boundary tooling, the upper threaded section 31 of the vertical column 3 has a longer axial length.

[0054] In order to facilitate the construction of the free expansion tooling, the lower pressing plate 8 is provided with an internal threaded hole matching the bottom threaded section 62 of the guide column 6. When disassembling, the guide column 6 is shifted to the internal threaded hole.

[0055] The present application also provides a battery cycle aging test method under multiple constraints, which includes step S01: fix the load sensor 11, the guide column 6, and the vertical column 3 on the bottom plate 2. Step S02: place the lower pressure plate 8 above the load sensor 11, and then place the battery 10 and the upper pressure plate 7 in sequence. Step S03: place an adapted compression spring 5 on the vertical column 3, and then cover the top plate 1. Step S1: move the entire battery cycle aging test device under multiple constraints to a compression tester, and use the compression tester to pressurize the top plate 1 downward. Among them, when the mechanical value of the compression tester reaches a predetermined value, keep the compression tester stationary and start screwing the nut 4. When the mechanical value of the compression tester returns to zero, the loading is completed. Step S2: place the displacement sensor 9 on the top plate 1, connect the displacement signal of the displacement sensor 9, and the force signal of the load sensor 11; connect the charging line to the positive and negative poles of the battery 10, and start the cycle aging experiment according to the predetermined charging current or discharge current. If the value output by the load sensor 11 during the test does not increase by more than 5% compared to the original value at the beginning of the test, the battery 10 is considered to have passed the test. Otherwise, it is considered that the battery 10 has expanded too much.

[0056] The battery cycle aging test method is a method for monitoring the cycle aging of the battery 10 in the laboratory. After the test starts, there is no need to take the battery 10 again.

[0057] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with this technology to understand the content of the present application and implement it. They cannot be used to limit the scope of protection of the present application. All equivalent changes or modifications made according to the spirit of the present application should be included in the scope of protection of the present application.

Claims

1. A battery aging detection device under multiple constraints, characterized in that: include: A flat plate assembly, the flat plate assembly comprising a top plate (1), an upper pressing plate (7), and a lower pressing plate (8) which are arranged in parallel from top to bottom, and the upper pressing plate (7) and the lower pressing plate (8) can jointly clamp a battery (10); A connecting column assembly, the connecting column assembly comprising a guide column (6) connected to the plate assembly, the upper pressing plate (7) and the lower pressing plate (8) having a linear lifting freedom along the guide column (6); A sensor assembly, the sensor assembly comprising a displacement sensor (9) and a load sensor (11), the displacement sensor (9) being assembled with the top plate (1), and a probe (91) of the displacement sensor (9) being in contact with an upper surface of the upper pressing plate (7); and A bottom plate (2), the bottom plate (2) is fixed to the bottom end of the guide column (6), and the load sensor (11) is clamped by the lower pressure plate (8) and the bottom plate (2).

2. The battery aging detection device under multiple constraints according to claim 1, characterized in that: The connecting column assembly further comprises a vertical column (3) arranged in parallel with the guide column (6), the bottom end of the vertical column (3) is fixed to the bottom plate (2), and the top end of the vertical column (3) is movably assembled with the top plate (1); The top end of the vertical column (3) is provided with an upper threaded section (31) penetrating the top plate (1), and the upper threaded section (31) is movably equipped with a nut (4), and the nut (4) is in contact with the upper surface of the top plate (1); The vertical column (3) is also sleeved with a compression spring (5), and the two ends of the compression spring (5) are in contact with the top plate (1) and the upper pressure plate (7) respectively.

3. The battery aging detection device under multiple constraints according to claim 2, characterized in that: The bottom end of the vertical column (3) is provided with a lower thread section (32) for threaded assembly with the bottom plate (2); the bottom end of the guide column (6) is provided with a bottom thread section (62) for threaded assembly with the bottom plate (2); the vertical column (3) between the upper thread section (31) and the lower thread section (32) is an optical axis, and the portion between the bottom thread section (62) and the upper end of the guide column (6) is an optical axis, and the optical axis is a cylinder; The compression spring (5) has several alternative specifications of different shapes, sizes and / or materials.

4. The battery aging detection device under multiple constraints according to claim 2, characterized in that: A plurality of the guide pillars (6) are symmetrically distributed on both sides of the battery aging detection device under multiple constraints, and a plurality of the vertical pillars (3) are symmetrically distributed on both sides of the battery aging detection device under multiple constraints.

5. The battery aging detection device under multiple constraints according to claim 1, characterized in that: A guide sleeve is movably mounted on the guide column (6), and the upper pressing plate (7) and the lower pressing plate (8) are both fixed to the guide sleeve. The guide sleeve has a flange portion mounted on the upper pressing plate (7) or the lower pressing plate (8).

6. The battery aging detection device under multiple constraints according to claim 1, characterized in that: The upper pressing plate (7) and the lower pressing plate (8) are each provided with bosses extending toward each other, and the bosses of the upper pressing plate (7) and the lower pressing plate (8) are capable of clamping the battery (10) together.

7. A combined tooling for batteries under multiple constraints, characterized in that: include: A free expansion tooling, the free expansion tooling comprising a top plate (1), an upper pressure plate (7), and a lower pressure plate (8) arranged in parallel from top to bottom; the top plate (1) and the lower pressure plate (8) are connected via a guide column (6), and the upper pressure plate (7) has a linear degree of freedom of lifting and lowering along the guide column (6); The upper pressing plate (7) and the lower pressing plate (8) in the free expansion tooling can jointly clamp the battery (10).

8. The combined tooling for batteries under multiple constraints according to claim 7, characterized in that: Also includes: A constant boundary tool, the constant boundary tool comprising an upper pressing plate (7), a lower pressing plate (8), and a bottom plate (2) arranged in parallel from top to bottom; the upper pressing plate (7) and the bottom plate (2) are connected via a vertical column (3), and the lower pressing plate (8) has a linear degree of freedom of lifting and lowering along the vertical column (3); The top end of the vertical column (3) is provided with an upper threaded section (31) penetrating the upper pressing plate (7), and the upper threaded section (31) is movably equipped with a nut (4), and the nut (4) is in contact with the upper surface of the upper pressing plate (7); The upper pressing plate (7) and the lower pressing plate (8) in the constant boundary tooling can jointly clamp the battery (10).

9. The assembly tool for batteries under multiple constraints according to claim 8, characterized in that: The top plate (1) in the free expansion tooling is equipped with a displacement sensor (9), and the probe (91) of the displacement sensor (9) is in contact with the upper surface of the upper pressing plate (7); A load sensor (11) is sandwiched between the lower pressing plate (8) and the bottom plate (2) in the constant boundary tooling.

10. A battery aging detection method under multiple constraints, characterized in that: It uses the battery aging detection device under multiple constraints as described in any one of claims 2 to 4, and the battery aging detection method under multiple constraints includes: Step S1: using a compression testing machine to pressurize the top plate (1); When the mechanical value of the compression tester reaches a predetermined value, the compression tester is kept stationary and the nut (4) is started to be screwed; when the mechanical value of the compression tester returns to zero, the loading is completed; Step S2: Assemble the displacement sensor (9) onto the top plate (1), connect the displacement signal of the displacement sensor (9) and the force signal of the load sensor (11); connect the charging line to the positive and negative poles of the battery (10), and start the cycle aging experiment according to the predetermined charging current or discharging current.

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