Battery cell monomer test clamp and battery pack test device

Abstract

The utility model discloses a battery cell monomer test clamp and a battery pack test device, and relates to the technical field of battery test equipment. The battery cell monomer test fixture comprises a fixing assembly, a plurality of foams and a plurality of fastening pieces. The fixing assembly comprises a first fixing plate and a second fixing plate, and the first fixing plate and the second fixing plate are arranged in a spaced mode in the first direction; the multiple foams are located on the side, facing the second fixing plate, of the first fixing plate and the side, facing the first fixing plate, of the second fixing plate correspondingly. The multiple fastening pieces sequentially penetrate through the first fixing plate and the second fixing plate in the first direction and are arranged on the two sides of the first fixing plate and the two sides of the second fixing plate at intervals in the second direction. By adopting the technology provided by the utility model, the restraint consistency of the to-be-tested battery can be effectively realized, and the cycle life of the to-be-tested battery is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of battery testing equipment, in particular to a battery cell testing fixture and a battery pack testing device. Background Art

[0002] Lithium-ion batteries are widely used in electric vehicles, household and industrial and commercial energy storage due to their high energy density, long cycle life, no memory effect and environmental protection. Among them, lithium-ion battery cells need to be connected in series and parallel and assembled in structure to form battery modules for terminal use. However, during the cycle of lithium-ion battery cells, due to the release and embedding of lithium ions between graphite layers, the metal lithium irreversibly settles on the negative electrode graphite surface, causing an uneven increase in the thickness of the battery cell.

[0003] At present, whether it is the testing of battery cells or the assembly of battery modules, the thickness increase is limited by restraint. Specifically, the restraint of battery cells is completed by a single fixture, and the restraint of battery modules is completed by the interaction force between batteries.

[0004] However, the above solution is prone to the following problems: during the clamping process of the single battery, the thickness of the battery itself will be slightly different, so the clamping state will also be different, resulting in errors in the tested electrical performance. Further, the cycle life of the single battery test and the battery cycle data after grouping will have performance differences due to the difference in the restraint method. Moreover, during the cycle test of the battery module, the cycle data of each single cell cannot be tested. Utility Model Content

[0005] The utility model provides a battery cell single-cell test fixture and a battery pack test device, so as to solve the problem of inconsistent restraint before single-cell battery testing in the prior art.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is to provide a battery cell single body test fixture, and the battery cell single body test fixture includes: a fixing component, a plurality of foams and a plurality of restraining pieces.

[0007] The fixing assembly includes a first fixing plate and a second fixing plate, and the first fixing plate and the second fixing plate are spaced apart along a first direction; the plurality of foams are respectively located on a side of the first fixing plate facing the second fixing plate and a side of the second fixing plate facing the first fixing plate.

[0008] The plurality of restraining members sequentially penetrate the first fixing plate and the second fixing plate along the first direction, and are spaced apart at both sides of the first fixing plate and the second fixing plate along the second direction.

[0009] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0010] The restraining member sequentially penetrates the first fixing plate and the second fixing plate along the first direction, so that the first fixing plate and the second fixing plate respectively apply restraining force to the battery to be tested located between the first fixing plate and the second fixing plate. There are multiple restraining members, which are spaced apart on both sides of the first fixing plate and the second fixing plate along the second direction, so that the battery to be tested can be subjected to the restraining force at every set distance, thereby ensuring the restraint consistency of the battery to be tested.

[0011] In order to offset the expansion of the battery under test in the early stage of the cycle test, foam is arranged between the battery under test and the first fixing plate and between the battery under test and the second fixing plate. Due to the deformability of the foam, the clamping force of the fixing component on the battery under test in the early stage of the cycle and the consistency of the thickness between the fixing components can be achieved, thereby improving the cycle life.

[0012] In some embodiments, the battery cell test fixture further includes a plurality of limit members, wherein the limit members are located between the first fixing plate and the second fixing plate along the first direction and are sleeved around the outer periphery of the restraining member.

[0013] By adopting the above technical solution, a limiting member is provided to limit the distance between the first fixing plate and the second fixing plate, which can effectively prevent the restraining member from causing the first fixing plate and the second fixing plate to exert excessive restraining force on the battery to be tested.

[0014] In some embodiments, the first fixing plate and the second fixing plate are respectively provided with a plurality of fixing holes, and the restraining member passes through the first fixing plate and the second fixing plate in sequence along the fixing holes, wherein the distance between two adjacent fixing holes on the first fixing plate and / or the second fixing plate is less than or equal to 40 mm.

[0015] In some embodiments, the locking member includes a locking bolt and a nut, the locking bolt passes through the first fixing plate and the second fixing plate in sequence along the fixing hole, the nut is located on the first fixing plate or the second fixing plate, and cooperates with the corresponding locking bolt thread.

[0016] By adopting the above technical solution, the distance between two adjacent fixing holes is the distance between two adjacent restraining parts. When the distance between two adjacent restraining parts is large, it is easy to cause inconsistent restraint forces of the first fixing plate and the second fixing plate on the battery to be tested, thereby causing inconsistent restraint before the battery test. Preferably, the distance between two adjacent fixing holes is less than or equal to 40 mm, so as to achieve better restraint consistency while saving the number of restraining parts.

[0017] In some embodiments, an insulating plate is further provided between the first fixing plate and / or the second fixing plate and the foam, wherein a surface area of ​​the insulating plate facing the first fixing plate or the second fixing plate is larger than a surface area of ​​the first fixing plate or the second fixing plate facing the insulating plate.

[0018] By adopting the above technical solution, an insulating plate is arranged between the foam and the first fixing plate or between the foam and the second fixing plate, which effectively improves the safety performance of the test fixture without affecting the deformable effect of the foam.

[0019] In some embodiments, a thickness of the first fixing plate and / or the second fixing plate along the first direction is greater than or equal to 10 mm.

[0020] In some embodiments, the first fixing plate, the second fixing plate and the limiting member are made of aluminum or steel or alloys thereof.

[0021] In some embodiments, the foam is made of polyurethane material or polystyrene material; the thickness of the foam along the first direction is greater than or equal to 1 mm.

[0022] In some embodiments, the present application also provides a battery pack testing device, comprising a plurality of the above-mentioned battery cell test fixtures, wherein a first fixing plate and a second fixing plate are spaced apart along a first direction, and a plurality of fastening members penetrate the plurality of first fixing plates and the second fixing plates in sequence along the first direction.

[0023] By adopting the above technical solution, compared with the current battery module that realizes the restraint of the battery module through the interaction force between multiple batteries, the multiple single cells of the battery module are restrained by the adjacent first fixed plate and the second fixed plate respectively, which can effectively test the cycle performance of each single cell in the battery module in the entire battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work, among which:

[0025] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of a battery cell test fixture provided by the utility model;

[0026] Figure 2 It is a side view of an embodiment of a battery cell test fixture provided by the utility model;

[0027] Figure 3 yes Figure 2 A magnified view of the local structure of part A;

[0028] Figure 4 This is a test cycle comparison diagram between a battery cell test fixture provided by the utility model and a conventional fixture;

[0029] Figure 5 It is a three-dimensional structural schematic diagram of an embodiment of a battery pack testing device provided by the utility model;

[0030] Figure 6 The utility model discloses a test cycle diagram of a battery pack test device.

[0031] In the figure:

[0032] Fixing assembly—10; first fixing plate—11; second fixing plate—12; fixing hole—13; insulating plate—14; foam—20;

[0033] The fixing piece is 30; the fixing bolt is 31; the nut is 32; the limiting piece is 40. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0035] In order to facilitate the subsequent description, before describing the specific structure of the battery cell test fixture, this application first combines Figure 1 A first direction (Z), a second direction (X), and a third direction (Y) are defined. The first direction is the height direction of the battery cell test fixture when it is normally placed, such as the Z direction; the second direction is the length direction of the battery cell test fixture when it is normally placed, such as the X direction; and the third direction is the width direction of the battery cell test fixture when it is normally placed, such as the Y direction. In this application, the first direction (Z), the second direction (X), and the third direction (Y) are perpendicular to each other.

[0036] It can be understood that the mutual perpendicularity in the present application is not absolute perpendicularity, and the approximate perpendicularity caused by processing errors and assembly errors (for example, the angle between two structural features is 89.9°) is also within the range of mutual perpendicularity in the present application.

[0037] See also Figure 1 As shown, Figure 1A three-dimensional structural schematic diagram of an embodiment of a battery cell test fixture provided by the present application is shown.

[0038] In some embodiments, the battery cell test fixture includes: a fixing component 10 , a plurality of foams 20 , and a plurality of restraining members 30 .

[0039] The fixing assembly 10 includes a first fixing plate 11 and a second fixing plate 12, which are spaced apart along a first direction; a plurality of foams 20 are respectively located on the first fixing plate 11 facing the second fixing plate 12 and the second fixing plate 12 facing the first fixing plate 11.

[0040] The plurality of restraining members 30 sequentially penetrate the first fixing plate 11 and the second fixing plate 12 along the first direction, and are spaced apart at both sides of the first fixing plate 11 and the second fixing plate 12 along the second direction.

[0041] In the embodiment of the present application, the restraining member 30 sequentially penetrates the first fixing plate 11 and the second fixing plate 12 along the first direction, so that the first fixing plate 11 and the second fixing plate 12 respectively apply restraining force to the battery under test located between the first fixing plate 11 and the second fixing plate 12.

[0042] The restraining member 30 has a plurality of, for example, Figure 1 The number of the restraining members 30 that can be provided is six, and the restraining members 30 are arranged at intervals on both sides of the first fixing plate 11 and the second fixing plate 12 along the second direction. Figure 1 It is shown as being symmetrically arranged along the second direction on both sides of the first fixing plate 11. The restraining member 30 enables the battery to be tested to be subjected to restraint force at every set distance, thereby ensuring the restraint consistency of the battery to be tested.

[0043] In addition, in order to offset the expansion of the battery under test in the early stage of the cycle test, foam 20 is respectively arranged between the battery under test and the first fixing plate 11 and between the battery under test and the second fixing plate 12. Due to the deformability of the foam 20, the clamping force of the fixing component 10 on the battery under test in the early stage of the cycle and the consistency of the thickness of the fixing component 10 can be achieved, thereby improving the cycle life.

[0044] In some embodiments, the battery cell test fixture further includes a plurality of limit members 40 , which are located between the first fixing plate 11 and the second fixing plate 12 along the first direction and are sleeved around the outer periphery of the restraining member 30 .

[0045] In the embodiment of the present application, a limiter 40 is provided to limit the distance between the first fixing plate 11 and the second fixing plate 12, which can effectively prevent the restraining member 30 from causing the first fixing plate 11 and the second fixing plate 12 to have too large a restraining force on the battery to be tested. The limiter 40 is a hollow cylinder.

[0046] Exemplarily, the thickness of the first fixing plate 11 or the second fixing plate 12 along the first direction is greater than or equal to 10 mm, and the first fixing plate 11, the second fixing plate 12 and the stopper 40 are made of aluminum or steel or their alloys to ensure the stability of the first fixing plate 11, the second fixing plate 12 and the stopper 40. The foam 20 is made of polyurethane material or polystyrene material, and the thickness of the foam 20 along the first direction is greater than or equal to 1 mm, so as to achieve better deformation to offset the expansion of the single battery.

[0047] See also Figures 2 to 3 As shown, Figure 2 A side view of an embodiment of a battery cell test fixture provided by the present application is shown. Figure 3 for Figure 2 A magnified view of the local structure of part A.

[0048] In some embodiments, a plurality of fixing holes 13 are respectively provided on the first fixing plate 11 and the second fixing plate 12, and the restraining member 30 passes through the first fixing plate 11 and the second fixing plate 12 in sequence along the fixing holes 13, wherein the distance between two adjacent fixing holes 13 on the first fixing plate 11 and / or the second fixing plate 12 is less than or equal to 40 mm.

[0049] The locking member 30 includes a locking bolt 31 and a nut 32 . The locking bolt 31 passes through the first fixing plate 11 and the second fixing plate 12 in sequence along the fixing hole 13 . The nut 32 is located on the first fixing plate 11 or the second fixing plate 12 and is threadedly matched with the corresponding locking bolt 31 .

[0050] In the embodiment of the present application, the distance between two adjacent fixing holes 13 is the distance between two adjacent restraining members 30. When the distance between two adjacent restraining members 30 is large, it is easy to cause inconsistent restraining forces of the first fixing plate 11 and the second fixing plate 12 on the battery to be tested, thereby causing inconsistent restraint before the battery test. Preferably, the distance between two adjacent fixing holes 13 is less than or equal to 40 mm. For example, along the third direction, the distance between two adjacent fixing holes 13 is 38 mm.

[0051] In some embodiments, an insulating plate 14 is further provided between the first fixing plate 11 or the second fixing plate 12 and the foam 20, wherein the surface area of ​​the insulating plate 14 facing the first fixing plate 11 or the second fixing plate 12 is greater than the surface area of ​​the first fixing plate 11 or the second fixing plate 12 facing the insulating plate 14.

[0052] In the embodiment of the present application, an insulating plate 14 is disposed between the foam 20 and the first fixing plate 11 or between the foam 20 and the second fixing plate 12, which effectively improves the safety performance of the test fixture without affecting the deformable effect of the foam 20. Exemplarily, the insulating plate 14 is, for example, an epoxy plate, an acrylic plate, or a plate made of other conductive polymer materials.

[0053] Combination Figure 1 As shown, the surface area of ​​the insulating plate 14 facing the first fixed plate 11 or the second fixed plate 12 is greater than the surface area of ​​the first fixed plate 11 or the second fixed plate 12 facing the insulating plate 14, which means that the length and width of the insulating plate 14 are greater than the length and width of the first fixed plate 11 and the second fixed plate 12.

[0054] See also Figure 4 As shown, Figure 4 A comparison chart of test cycles between a battery cell test fixture provided by the present application and a conventional fixture is shown.

[0055] In some application scenarios, both conventional fixtures and battery cell test fixtures are used to test square lithium iron phosphate batteries. The foam 20 of the battery cell test fixture provided in this application is 1 mm EVA (ethylene-vinyl acetate copolymer) foam, the limiter 40 is 30 mm long, and the clamping force of the fixing component 10 is 200 kg; the clamping force of the conventional fixture is 200 kg.

[0056] The cycle test conditions are: 45°C, 0.5C constant current and constant voltage charging / 0.5C constant current and constant voltage discharging.

[0057] Combination Figure 4 According to the cycle test results data, the battery life of the lithium iron phosphate battery tested by the conventional fixture without the limiter 40 and the foam 20 is 1850 times @80% SOH; while the battery cell test fixture based on the present application (with the limiter 40, the foam 20 and the fixing component 10, but without the insulating plate 14) meets the test data of 2500 times @80% SOH for the lithium iron phosphate battery.

[0058] It can be determined that the battery cell test provided in the present application can solve the problem of consistent clamping force and thickness of the battery cell in the early stage by offsetting the early expansion of the battery cell through the foam 20, thereby improving the cycle life of the battery cell.

[0059] See also Figures 5 and 6 As shown, Figure 5 A schematic diagram of the three-dimensional structure of an embodiment of a battery pack testing device provided by the present application is shown; Figure 6 A test cycle diagram of a battery pack testing device provided by the present application is shown.

[0060] In some embodiments, the present application also provides a battery pack testing device, comprising a plurality of the above-mentioned battery cell test fixtures, wherein the first fixing plate 11 and the second fixing plate 12 are spaced apart along a first direction, and a plurality of restraining members 30 penetrate the plurality of first fixing plates 11 and second fixing plates 12 in sequence along the first direction.

[0061] In the embodiment of the present application, compared with the current battery module that realizes the restraint of the battery module through the interaction force between multiple batteries, the multiple single cells of the battery module are restrained by the adjacent first fixing plate 11 and the second fixing plate 12 respectively, which can effectively test the cycle performance of each single cell in the battery module in the entire battery module.

[0062] in, Figure 5 Four single cells can be tested simultaneously, but the present application does not limit the number of the first fixing plate 11, the second fixing plate 12, and the limiting member 40. By increasing the number of the restraining member 30 and adding the first fixing plate 11, the second fixing plate 12, and the limiting member 40, more battery cells can be accommodated for testing.

[0063] For example, the first fixing plate 11 and the second fixing plate 12 have the same substantial structure. Figure 1 As shown, the first fixing plate 11 or the second fixing plate 12 located inside applies a restraining force to the battery cells on both sides along the first direction respectively.

[0064] In some application scenarios, Figure 5 The battery pack testing device shown is used for testing the performance of square lithium iron phosphate batteries, wherein the foam 20 of the battery pack testing device provided in the present application is 1 mm EVA foam, the length of the limiter 40 is 30 mm, and the clamping force of the fixing assembly 10 is 200 kg.

[0065] The cycle test conditions are: 25℃, 0.5C constant current and constant voltage charging / 0.5C constant current and constant voltage discharging.

[0066] Combination Figure 6 According to the cycle test result data, the cycles of the four cells, cell No. 1, cell No. 2, cell No. 3 and cell No. 4, are highly consistent. It can be determined that the battery pack test device provided by the present application can test the cycle performance of each single cell in the battery module in the entire battery module by using the foam 20 to offset the early expansion of the battery cell, thereby improving the cycle life of the battery cell.

[0067] The above description is only an implementation method of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present utility model, or directly or indirectly used in other related technical fields, should be included in the protection scope of the present utility model.

Claims

1. A battery cell test fixture, characterized in that: include: A fixing assembly, the fixing assembly comprising a first fixing plate and a second fixing plate, the first fixing plate and the second fixing plate being spaced apart along a first direction; A plurality of foams, wherein the plurality of foams are respectively located on a side of the first fixing plate facing the second fixing plate and a side of the second fixing plate facing the first fixing plate; A plurality of restraining members are provided, wherein the plurality of restraining members sequentially penetrate the first fixing plate and the second fixing plate along the first direction, and are spaced apart at both sides of the first fixing plate and the second fixing plate along the second direction.

2. The battery cell test fixture according to claim 1, characterized in that: The battery cell test fixture further includes a plurality of limit members, wherein the limit members are located between the first fixing plate and the second fixing plate along the first direction and are sleeved on the outer periphery of the restraining member.

3. The battery cell test fixture according to claim 1, characterized in that: The first fixing plate and the second fixing plate are also respectively provided with a plurality of fixing holes, and the restraining member passes through the first fixing plate and the second fixing plate in sequence along the fixing holes, wherein the distance between two adjacent fixing holes on the first fixing plate and / or the second fixing plate is less than or equal to 40 mm.

4. The battery cell test fixture according to claim 3, characterized in that: The locking member includes a locking bolt and a nut. The locking bolt passes through the first fixing plate and the second fixing plate in sequence along the fixing hole. The nut is located on the first fixing plate or the second fixing plate and cooperates with the corresponding locking bolt thread.

5. The battery cell test fixture according to claim 1, characterized in that: An insulating plate is also provided between the first fixing plate and / or the second fixing plate and the foam, wherein a surface area of ​​the insulating plate facing the first fixing plate or the second fixing plate is larger than a surface area of ​​the first fixing plate or the second fixing plate facing the insulating plate.

6. The battery cell test fixture according to claim 1, characterized in that: The thickness of the first fixing plate and / or the second fixing plate along the first direction is greater than or equal to 10 mm.

7. The battery cell test fixture according to claim 1, characterized in that: The first fixing plate, the second fixing plate and the limiting member are made of aluminum or steel or alloys thereof.

8. The battery cell test fixture according to claim 1, characterized in that: The foam is made of polyurethane material or polystyrene material.

9. The battery cell test fixture according to claim 1, characterized in that: The thickness of the foam along the first direction is greater than or equal to 1 mm.

10. A battery pack testing device, characterized in that: A plurality of battery cell test fixtures comprising any one of claims 1 to 9, wherein the first fixing plates and the second fixing plates are spaced apart along a first direction, and a plurality of restraining members sequentially penetrate the plurality of the first fixing plates and the second fixing plates along the first direction.

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