Prestressed glass clamp for soft package battery cell

Abstract

The utility model discloses a kind of soft package battery cell prestress glass clamps, belong to lithium battery testing technical field, including two identical glass plates, respectively as upper glass plate and lower glass plate, and two blocks of well character supports, respectively as upper well character support and lower well character support;Upper glass plate and lower glass plate are clamped between the soft package battery cell to be tested;Upper well character support is placed on the upside of upper glass plate, and lower well character support is placed on the downside of lower glass plate;Well character support includes mutually parallel first bar, first bar both ends connecting lug plate, and bolt hole is set on lug plate;Pressure bolt is arranged in bolt hole;Multiple second bars are perpendicular to first bar and are connected with first bar, and second bar divides first bar into multiple equal parts.Solve the problem that existing technology uses iron or steel or aluminum alloy material, both sides are fixed using locking screw, so that the stress in test fixture is larger, it has influence on lithium ion battery test, and the processing cost is higher simultaneously.

Description

Technical Field

[0001] This utility model belongs to the field of lithium battery testing technology, specifically relating to a prestressed glass clamp for soft-pack battery cells. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Lithium-ion batteries are widely used due to their advantages such as high energy density, high voltage, high cycle life, and high operating temperature. During testing of pouch lithium-ion batteries, fixtures are needed to simulate the stress state of the pouch cells within the module.

[0004] The prior art discloses a pressurized formation fixture for pouch batteries, including a first clamping plate, a second clamping plate, and a pressurizing part. The first clamping plate and the second clamping plate have through holes, and the pressurizing part includes a locking screw and a nut. The locking screw passes through the through holes of the two clamping plates and includes a locking wrench end, a rod body, and a threaded end. The pouch battery cell is fixed and pressurized by pre-tightening the nut and fastening the locking wrench.

[0005] In the above scheme, the clamps are made of iron, steel or aluminum alloy. The soft-pack battery cell is placed in the center of two iron, steel or aluminum alloy clamps and fixed on both sides with locking screws. This results in greater stress in the middle of the test fixture, which affects the lithium-ion battery test and also increases the processing cost. Iron, steel or aluminum alloy has a large coefficient of linear expansion and is conductive. When used in high-temperature environments, it is prone to dimensional instability and safety accidents. Utility Model Content

[0006] In view of this, the present invention provides a prestressed glass clamp for soft-pack battery cells, which can solve the problems of existing technologies that use iron, steel or aluminum alloy materials and are fixed on both sides with locking screws, resulting in large stress in the middle of the test clamp, which affects the testing of lithium-ion batteries, and also has high processing costs.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A prestressed glass clamp for a soft-pack battery cell is provided, comprising two glass plates of the same size, namely an upper glass plate and a lower glass plate, and two grid brackets, namely an upper grid bracket and a lower grid bracket; the soft-pack battery cell to be tested is clamped between the upper glass plate and the lower glass plate;

[0009] The upper grid bracket is placed on the upper side of the upper glass plate, and the lower grid bracket is placed on the lower side of the lower glass plate;

[0010] Each grid support includes a first rod that is parallel to each other. The two ends of the first rod are connected to ear plates, and bolt holes are opened on the ear plates. Pressure bolts are inserted into the bolt holes.

[0011] Multiple second poles are perpendicular to and connected to the first pole, and the second poles divide the first pole into multiple equal parts.

[0012] Preferably, the ear plate is connected to the first protrusion on the side facing the first rod, and the length between the first protrusions is equal to the length of the glass plate.

[0013] Preferably, the two ends of the second rod are connected to the second protrusions, and the length between the second protrusions is equal to the length of the glass plate.

[0014] Preferably, the first protrusion of the first rod and the second protrusion of the second rod form a groove for placing the glass plate.

[0015] Preferably, the upper grid bracket and the lower grid bracket are arranged opposite to each other, that is, the sides with the first protrusion and the second protrusion are arranged opposite to each other; when the upper grid bracket and the lower grid bracket are arranged opposite to each other, the vertical projections of the first rod, the ear plate and the bolt hole coincide.

[0016] Preferably, the height of the first protrusion is less than the thickness of the glass plate.

[0017] Preferably, when the upper grid support and the lower grid support are arranged opposite each other, the vertical projection of the second rod is separated.

[0018] Preferably, the height of the second protrusion of the second rod is greater than the thickness of the glass plate.

[0019] Preferably, the pressure bolt includes a screw rod, one end of which is fixed with a hexagonal bolt head. After passing through the bolt holes of the upper and lower grid brackets, the screw rod is threadedly connected to a nut. The nut is positioned above the upper grid bracket.

[0020] Preferably, a hexagonal hole is opened at the bottom of the bolt hole of the lower grid bracket, and a hexagonal bolt head is fixed in the hexagonal hole.

[0021] Compared with the prior art, the advantages and positive effects of this utility model are:

[0022] This invention uses two glass plates to clamp the soft-pack battery cell to be tested. A grid-like support is set on the outside of the glass plates to apply prestress to the glass plates. The grid-like support, formed by the first and second rods, can evenly apply the prestress to the glass plates. This solves the technical problem in the prior art where the soft-pack battery cell is placed in the center of two iron, steel, or aluminum alloy clamping plates and fixed on both sides with locking screws, resulting in high stress in the middle of the test fixture, which affects the testing of lithium-ion batteries. Furthermore, replacing the iron, steel, or aluminum alloy clamping plates with glass plates reduces the processing cost and also solves the technical problem that iron, steel, or aluminum alloy materials have a large coefficient of linear expansion and are conductive, which can easily lead to dimensional instability and safety accidents when used in high-temperature environments. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0024] Figure 1 This is an exploded view of the soft-pack prestressed glass clamp according to an embodiment of the present invention;

[0025] Figure 2 This is a top view of the soft-pack prestressed glass clamp according to an embodiment of the present utility model;

[0026] Figure 3 This is a bottom view of the soft-pack prestressed glass clamp according to an embodiment of the present utility model;

[0027] Figure 4 This is a comparison chart showing the results of charge-discharge cycle performance tests conducted at 25°C on a soft-pack prestressed glass clamp and a steel plate or aluminum alloy clamp according to an embodiment of this utility model.

[0028] Figure 5 This is a comparison chart showing the results of charge-discharge cycle performance tests conducted at 45°C on a soft-pack prestressed glass clamp and a steel plate or aluminum alloy clamp according to an embodiment of this utility model.

[0029] In the picture:

[0030] 1. Glass plate; 11. Upper glass plate; 12. Lower glass plate; 2. Grid support; 21. Upper grid support; 22. Lower grid support; 23. First rod; 24. Second rod; 25. Ear plate; 26. Bolt hole; 27. First protrusion; 28. Second protrusion; 3. Pressure bolt; 31. Screw; 32. Hex bolt head; 33. Nut. Detailed Implementation

[0031] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] This embodiment discloses a prestressed glass clamp for soft-pack battery cells, such as Figure 1As shown, the device includes two glass plates 1 of the same size and two grid-like supports 2 on the outer side of the glass plates for applying prestress. The two grid-like supports 2 are connected by pressure bolts 3. Specifically, the two glass plates 1 are an upper glass plate 11 and a lower glass plate 12, and the two grid-like supports 2 are an upper grid-like support 21 and a lower grid-like support 22. The upper glass plate 11 and the lower glass plate 12 are used to place and clamp the soft-pack battery cell to be tested. The upper grid-like support 21 is placed on the upper side of the upper glass plate 11, and the lower grid-like support 22 is placed on the lower side of the lower glass plate 12. Prestress is applied to the upper glass plate 11 and the lower glass plate 12 through the upper grid-like support 21 and the lower grid-like support 22.

[0034] like Figures 1 to 3 As shown, both the upper grid bracket 21 and the lower grid bracket 22 include a first rod 23 that is parallel to each other. The two ends of the first rod 23 are fixedly connected to the ear plate 25 (in this embodiment, the ear plate 25 is integrally made with the first rod 23). The top and bottom surfaces of the ear plate 25 are flush with the first rod 23. Bolt holes 26 are opened on the ear plate 25. The bolt holes 26 are used to insert the pressure bolts 3. The upper grid bracket 21 is placed on the upper side of the upper glass plate 11, and the lower glass plate 12 is placed on the lower grid bracket 22, so that the ear plates 25 of the upper grid bracket 21 and the lower grid bracket 22 are aligned, and the bolt holes 26 are aligned vertically. Then, the pressure bolts 3 are inserted and tightened in them. The pressure bolts 3 are tightened to apply prestress to the upper grid bracket 21 and the lower grid bracket 22. Then, the prestress is transferred to the upper glass plate 11 and the lower glass plate 12 through the upper grid bracket 21 and the lower grid bracket 22 to apply prestress to the soft-pack battery cell to be tested clamped therein.

[0035] In this embodiment, there are two first rods 23, and the glass plate 1 is made of prestressed glass (also called tempered glass).

[0036] like Figures 1 to 3 As shown, the upper grid support 21 or the lower grid support 22 also includes multiple second rods 24. The second rods 24 are perpendicular to the first rod 23 and are fixedly connected to the first rod 23 (in this embodiment, the first rod 23 and the second rod 24 are integrally manufactured). The second rods 24 divide the first rod 23 into multiple equal parts.

[0037] In this embodiment, there are two second rods 24. The first rod 23 and the second rod 24 together form a grid-shaped support. This grid-shaped support structure can evenly apply the prestress to the upper glass plate 11 and the lower glass plate 12 when applying prestress. This can solve the technical problem in the prior art where the soft-pack battery cell is placed in the center of two iron, steel or aluminum alloy clamps and fixed on both sides with locking screws, resulting in large stress in the middle of the test fixture, which affects the lithium-ion battery test. Furthermore, replacing the iron, steel or aluminum alloy clamps with glass plates reduces the processing cost and also solves the technical problem that iron, steel or aluminum alloy materials have a large coefficient of linear expansion and are conductive, which can easily lead to dimensional instability and safety accidents when used in high-temperature environments.

[0038] like Figures 1 to 3 As shown, the upper glass plate 11 and the lower glass plate 12 are rectangular plates, which facilitates processing. In this embodiment, the upper glass plate 11 and the lower glass plate 12 are square plates.

[0039] like Figures 1 to 3 As shown, the ear plate 25 is fixedly connected to the first protrusion 27 on the side facing the first rod 23 (in this embodiment, the first protrusion 27 and the first rod 23 are integrally manufactured). The length between the first protrusions 27 is equal to the length of the glass plate 1. Placing the glass plate 1 between the first protrusions 27 can limit the displacement of the glass plate 1 in the direction of the length of the first rod 23.

[0040] like Figures 1 to 3 As shown, the two ends of the second rod 24 are fixedly connected to the second protrusions 28 (in this embodiment, the second protrusions 28 and the second rod 24 are integrally manufactured), and the length between the second protrusions 28 is equal to the length of the glass plate 1. Placing the glass plate 1 between the second protrusions 28 can limit the displacement of the glass plate 1 along the length direction of the second rod 24.

[0041] like Figure 1 As shown, the first protrusion 27 and the second protrusion 28 of the first rod 23 and the second rod 24 form a groove for placing the glass plate 1. The groove can restrict the position of the glass plate 1, ensuring that the glass plate 1 will not shift when prestress is applied, thus preventing deviations during prestress application and affecting the accuracy of the test results.

[0042] like Figures 1 to 3As shown, the upper grid bracket 21 and the lower grid bracket 22 are arranged opposite each other, that is, the sides with the first protrusion 27 and the second protrusion 28 are arranged opposite each other; when the upper grid bracket 21 and the lower grid bracket 22 are arranged opposite each other, the vertical projections of the first rod 23, ear plate 25 and bolt hole 26 of the upper grid bracket 21 and the lower grid bracket 22 all coincide. This allows the pressure bolt 3 to pass through the bolt hole 26 of the upper grid bracket 21 and the lower grid bracket 22, applying prestress to the glass plate 1 between the upper grid bracket 21 and the lower grid bracket 22.

[0043] like Figures 1 to 3 As shown, the height of the first protrusion 27 is less than the thickness of the glass plate 1. When the pressure bolt 3 passes through the bolt holes 26 of the upper grid bracket 21 and the lower grid bracket 22 and applies prestress to the glass plate 1 between the upper grid bracket 21 and the lower grid bracket 22, the first protrusion 27 of the upper grid bracket 21 and the lower grid bracket 22 cannot make relative contact, thus failing to prevent the application of prestress to the glass plate 1 between the upper grid bracket 21 and the lower grid bracket 22.

[0044] like Figures 1 to 3 As shown, when the upper grid bracket 21 and the lower grid bracket 22 are arranged opposite each other, the vertical projection of the second rod 24 is separated; and the height of the second protrusion 28 is greater than the thickness of the glass plate 1.

[0045] The reason for this design is that when the upper grid bracket 21 and the lower grid bracket 22 are set opposite each other, the upper glass plate 11 and the lower glass plate 12 need to be stacked. The height of the first protrusion 27 is less than the height of the glass plate 1. When the upper glass plate 11 is placed on the lower glass plate 12, there may be a misalignment. However, the height of the second protrusion 28 is greater than the height of the glass plate 1. When the upper glass plate 11 is placed on the lower glass plate 12, it can play a certain positioning role for the upper glass plate 11. Then the upper grid bracket 21 can be installed. However, if the upper grid bracket 21 and the lower grid bracket 22 are set opposite each other, the vertical projection of the second rod 24 will coincide with each other. This will cause the second protrusion 28 of the upper grid bracket 21 and the lower grid bracket 22 to contact each other, so that the upper grid bracket 21 cannot contact the upper glass plate 11. Therefore, it is impossible to apply prestress to the soft-pack battery cell to be tested between the upper glass plate 11 and the lower glass plate 12.

[0046] like Figures 1 to 3 As shown, the pressure bolt 3 includes a screw 31, one end of which is fixed with a hexagonal bolt head 32, and a nut 33 is threaded onto the screw 31. After the screw 31 passes through the bolt holes 26 of the upper grid bracket 21 and the lower grid bracket 22, it is threaded onto the nut 33. By tightening the nut 33, prestress is applied to the glass plate 1 between the upper grid bracket 21 and the lower grid bracket 22.

[0047] like Figures 1 to 3As shown, the nut 33 of the pressure bolt 3 needs to be placed above the upper grid bracket 21 so that the nut 33 can be turned by the digital torque wrench. Before the test, adjust the preset pressure of the digital torque wrench to the current preset pressure, and slowly tighten the nut 33 in a crisscross pattern. After the preset pressure is reached for the first time, tighten it twice to ensure that the pressure at each point reaches the preset pressure.

[0048] like Figure 3 As shown, a hexagonal hole (not shown in the figure) is opened at the bottom of the bolt hole 26 of the lower grid bracket 22. The size of the hexagonal hole is the same as that of the hexagonal bolt head 32, which is used to fix the hexagonal bolt head 32 of the pressure bolt 3. This prevents the screw 31 from rotating when the nut 33 is turned after the screw 31 is threadedly connected to the nut 33.

[0049] like Figure 4 , Figure 5 As shown, twelve soft-pack battery cells of the same group and capacity were taken and divided into two groups. One group was tested for charge-discharge cycle performance at an ambient temperature of 25°C, and the other group was tested for charge-discharge cycle performance at an ambient temperature of 45°C. Of the six soft-pack battery cells in each group, three were clamped using the soft-pack battery cell prestressed glass clamp of this embodiment, and the other three were clamped using clamps made of steel plate or aluminum alloy material from the prior art.

[0050] Test results are as follows Figure 4 , Figure 5 As shown, through charge-discharge cycle performance tests conducted at ambient temperatures of 25°C and 45°C, the capacity retention rate of the pouch cell tested under a prestressed glass fixture is superior to that of the pouch cell tested under a fixture made of steel plate or aluminum alloy in the prior art.

[0051] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A prestressed glass clamp for flexible battery cells, characterized in that, It includes two glass plates of the same size, namely an upper glass plate and a lower glass plate, and two grid-like brackets, namely an upper grid-like bracket and a lower grid-like bracket; the soft-pack battery cell to be tested is clamped between the upper glass plate and the lower glass plate; The upper grid bracket is placed on the upper side of the upper glass plate, and the lower grid bracket is placed on the lower side of the lower glass plate; Each of the grid-shaped brackets includes a first rod that is parallel to each other. The two ends of the first rod are connected to ear plates, and bolt holes are opened on the ear plates. A pressure bolt is inserted into the bolt holes. Multiple second rods are perpendicular to the first rod and connected to the first rod, and the second rods divide the first rod into multiple equal parts.

2. The prestressed glass clamp for a flexible battery cell as described in claim 1, characterized in that, The ear plate is connected to a first protrusion on the side facing the first rod, and the length between the first protrusions is equal to the length of the glass plate.

3. The prestressed glass clamp for a flexible battery cell as described in claim 2, characterized in that, The two ends of the second rod are connected to the second protrusions, and the length between the second protrusions is equal to the length of the glass plate.

4. The prestressed glass clamp for a flexible battery cell as described in claim 3, characterized in that, The first protrusion of the first rod and the second protrusion of the second rod form a groove for placing the glass plate.

5. The prestressed glass clamp for a flexible battery cell as described in claim 4, characterized in that, The upper grid bracket and the lower grid bracket are arranged opposite to each other, that is, the sides with the first protrusion and the second protrusion are arranged opposite to each other; when the upper grid bracket and the lower grid bracket are arranged opposite to each other, the vertical projections of the first rod, the ear plate and the bolt hole coincide.

6. The prestressed glass clamp for a flexible battery cell as described in claim 5, characterized in that, The height of the first protrusion is less than the thickness of the glass plate.

7. The prestressed glass clamp for a flexible battery cell as described in claim 5, characterized in that, When the upper grid support and the lower grid support are arranged opposite each other, the vertical projection of the second rod is separated.

8. The prestressed glass clamp for a flexible battery cell as described in claim 7, characterized in that, The height of the second protrusion of the second rod is greater than the thickness of the glass plate.

9. A prestressed glass clamp for a flexible battery cell as described in claim 1, characterized in that, The pressure bolt includes a screw rod, one end of which is fixed with a hexagonal bolt head. The screw rod passes through the bolt holes of the upper and lower grid brackets and is threadedly connected to a nut. The nut is located above the upper grid bracket.

10. A prestressed glass clamp for a flexible battery cell as described in claim 9, characterized in that, The bottom of the bolt holes of the lower grid bracket is provided with hexagonal holes, and the hexagonal bolt heads are fixed in the hexagonal holes.

Images