Short-circuit testing system for bare battery cells

Abstract

This invention discloses a short-circuit testing system for bare battery cell assemblies, comprising a tester and multiple connection mechanisms. The tester includes a positive detection terminal and a negative detection terminal. The bare battery cell assembly includes multiple stacked cells, each cell including a lead terminal with a positive terminal and a negative terminal. The positive terminals of the multiple cells are connected to the positive detection terminal of the tester through the multiple connection mechanisms, and the negative terminals of the multiple cells are connected to the negative detection terminal of the tester through the multiple connection mechanisms. This invention enables rapid identification of the short-circuit point and improves the accuracy of short-circuit testing.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a short-circuit testing system for bare battery cell packs. Background Technology

[0002] Stacking is a crucial step in lithium-ion battery manufacturing. After stacking, the bare cells need to undergo short-circuit testing to confirm the connection between their positive and negative electrodes, ensuring product safety. Locating and analyzing short-circuit points is an important part of routine short-circuit improvement work. Utility Model Content

[0003] Existing methods for short-circuit testing of bare battery cells mostly involve manual searching using a handheld multimeter or short-circuit tester, layer by layer. This method suffers from problems such as complex testing processes and a tendency to miss or misdiagnose short circuits. A key area for improvement is how to quickly and accurately pinpoint the short circuit point within the bare battery cell. To overcome the shortcomings and deficiencies of existing technologies, the purpose of this invention is to provide a short-circuit testing system for bare battery cell assemblies that can quickly locate the short circuit point and improve the accuracy of short-circuit testing.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] A short-circuit testing system for bare battery cell arrays includes a tester and multiple connection mechanisms. The tester includes a positive detection terminal and a negative detection terminal. The bare battery cell array includes multiple stacked battery cells, each of which includes a lead terminal with a positive terminal and a negative terminal. The positive terminals of the multiple battery cells are connected to the positive detection terminal of the tester through the multiple connection mechanisms, and the negative terminals of the multiple battery cells are connected to the negative detection terminal of the tester through the multiple connection mechanisms.

[0006] In one embodiment, a controller is connected in series with each of the connection mechanisms.

[0007] In one embodiment, the controller is a switch.

[0008] In one embodiment, along the stacking direction of the bare battery cell assembly, the lead terminals on the same side have the same polarity.

[0009] In one embodiment, the connection mechanism includes a clamping plate having a conductive surface and an insulating surface disposed opposite to each other. The conductive surface is used for electrical connection with any of the lead terminals, and the insulating surface is used to isolate the lead terminal adjacent to it in the stacking direction of the bare cell assembly.

[0010] In one embodiment, the connection mechanism includes a conductive plate and an insulating plate stacked together, the conductive plate being used for electrical connection with one of the leads, and the insulating plate being used to isolate another lead adjacent to it in the stacking direction of the bare cell assembly.

[0011] In one embodiment, the short-circuit test system further includes a cell pressing mechanism for pressing the cells of the bare cell assembly during testing.

[0012] In one embodiment, the cell pressing mechanism includes a cell pressing cylinder and a cell pressing plate. Along the stacking direction of the bare cell assembly, the cell pressing plate is disposed on one side of the bare cell assembly, and the output end of the cell pressing cylinder is connected to the cell pressing plate.

[0013] In one embodiment, the short-circuit test system for bare cell assembly further includes a tab clamping mechanism for clamping the lead terminals during testing.

[0014] In one embodiment, the tab pressing mechanism includes multiple tab pressing cylinders and multiple tab pressing plates. Along the stacking direction of the bare cell assembly, the multiple tab pressing plates are correspondingly disposed on both sides of the stacked lead-out terminals, and the output end of one tab pressing cylinder is correspondingly connected to one tab pressing plate.

[0015] The beneficial effects of this utility model are as follows: the positive terminals of multiple battery cells are connected to the positive detection terminal of the tester through multiple connection mechanisms, and the negative terminals of multiple battery cells are connected to the negative detection terminal of the tester through multiple connection mechanisms. By testing the connectivity of each layer of battery cells through the tester, it can not only detect whether the bare battery cell group is short-circuited, but also determine which layer the short circuit is in, quickly and accurately pinpointing the short circuit point in which layer of the bare battery cell group, thereby improving the accuracy and efficiency of short circuit testing of bare battery cell groups. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a short-circuit testing system for bare battery cells according to an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 A schematic diagram of the bare battery cell assembly in the diagram;

[0019] Figure 3 yes Figure 1 A partial schematic diagram showing the connection between the connecting mechanism and the lead-out terminal;

[0020] Figure 4 This is a partial schematic diagram of the connection mechanism and the lead-out terminal in another embodiment;

[0021] Figure 5 yes Figure 4 A partial schematic diagram showing the connection mechanism connecting to the bare battery cell assembly.

[0022] In the diagram: 1. Tester; 11. Positive detection terminal; 12. Negative detection terminal; 2. Connection mechanism; 21. Controller; 22. Clamping plate; 221. Conductive surface; 222. Insulating surface; 23. Conductive plate; 24. Insulating plate; 3. Cell pressing mechanism; 31. Cell pressing cylinder; 32. Cell pressing plate; 4. Tab pressing mechanism; 41. Tab pressing cylinder; 42. Tab pressing plate; 5. Bare cell assembly; 51. Cell; 511. Positive electrode plate; 512. Negative electrode plate; 513. Diaphragm; 514. Lead-out terminal; 514A. Positive terminal; 514B. Negative terminal; 6. Control system. Detailed Implementation

[0023] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of this utility model. Based on the description of this utility model, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0025] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0027] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0028] This utility model provides a short-circuit testing system for bare battery cell assemblies, such as... Figure 1 and Figure 2 As shown, the device includes a tester 1 and multiple connection mechanisms 2. The tester 1 includes a positive detection terminal 11 and a negative detection terminal 12. The bare cell group 5 includes multiple stacked cells 51. Each cell 51 includes a lead terminal 514. The lead terminal 514 includes a positive terminal 514A and a negative terminal 514B. The positive terminals 514A of the multiple cells 51 are connected to the positive detection terminal 11 of the tester 1 through multiple connection mechanisms 2, and the negative terminals 514B of the multiple cells 51 are connected to the negative detection terminal 12 of the tester 1 through multiple connection mechanisms 2.

[0029] In this embodiment, the positive terminals 514A of multiple battery cells 51 are connected to the positive detection terminal 11 of the tester 1 through multiple connection mechanisms 2, and the negative terminals 514B of multiple battery cells 51 are connected to the negative detection terminal 12 of the tester 1 through multiple connection mechanisms 2. This enables the tester 1 to test the connectivity of each layer of battery cells 51, which can not only detect whether the bare battery cell group 5 is short-circuited, but also determine which layer the short circuit is in, quickly and accurately pinpointing the short circuit point in which layer of the bare battery cell group 5, thereby improving the accuracy and efficiency of short circuit testing of the bare battery cell group 5.

[0030] Among them, such as Figure 1-3As shown, the bare cell assembly 5 is a layered structure formed by stacking multiple cells 51, with each layer consisting of one cell 51. Each cell 51 includes a positive electrode 511, a negative electrode 512, and a separator 513. The portions of the positive electrode 511 and the negative electrode 512 extending beyond the separator 513 on opposite sides form the aforementioned lead terminals 514, namely the positive terminal 514A and the negative terminal 514B. The positive terminal 514A corresponds to the positive electrode tab led out from the positive electrode 511, and the negative terminal 514B corresponds to the negative electrode tab led out from the negative electrode 512. When the separator 513 between adjacent positive electrode 511 and negative electrode 512 has pinholes, scratches, uneven thickness, or mechanical damage, or when metal particles in the production environment puncture the separator 513, a short circuit can easily occur between the two adjacent electrodes (positive electrode 511 and negative electrode 512). Of course, this embodiment can also be applied to the portion of the positive electrode 511 and the negative electrode 512 extending beyond the separator 513 on the same side to form a lead terminal 514. In this embodiment, by controlling the on / off state of the circuits of each cell 51, the tester 1 can detect the overall conduction state of the bare cell group 5 and the conduction state of each cell 51, so as to detect whether the bare cell group 5 is short-circuited, and can specifically determine which layer is short-circuited.

[0031] As one implementation method, such as Figure 1 As shown, each connecting mechanism 2 is connected in series with a controller 21. The controller 21 controls the on / off state of the circuits of each cell 51, so that the tester 1 can detect the overall conduction state of the bare cell group 5 and the conduction state of each cell 51, so as to detect whether the bare cell group 5 is short-circuited, and can specifically determine which layer is short-circuited.

[0032] In one implementation, the controller 21 is a switch. The switch can be selected as a manual switch or an electromagnetic switch.

[0033] As one implementation method, such as Figure 1 and Figure 2 As shown, along the stacking direction T of the bare cell assembly 5, the terminals 514 on the same side have the same polarity. Specifically, multiple positive terminals 514A and multiple negative terminals 514B form a mirror-symmetrical layout, and the positive / negative connection lines can be routed parallel to each other along the stacking direction T, which facilitates the installation position of the standardized connection mechanism 2; through layer-by-layer analysis and judgment, the time for locating abnormal points can be shortened, and the testing efficiency can be improved.

[0034] As one implementation method, such as Figure 4As shown, the connecting mechanism 2 includes a clamping plate 22, which includes a conductive surface 221 and an insulating surface 222 disposed opposite to each other. The conductive surface 221 is used for electrical connection with any of the lead-out terminals 514, and the insulating surface 222 is used to isolate the bare cell assembly 5 from the adjacent lead-out terminal 514 in the stacking direction T. Specifically, the clamping plate 22 can be a metal plate (such as a copper plate), and the conductive surface 221 is a conductive metal. It is connected to the tester 1 through the wires of the connecting mechanism 2. An insulating material (such as polytetrafluoroethylene) can be coated on the opposite side of the conductive surface 221 to form the insulating surface 222, which is used to isolate adjacent lead-out terminals 514. During testing, the conductive surface 221 of the clamping plate 22 is attached to the target lead-out terminal 514, and the insulating surface 222 faces the adjacent lead-out terminal 514 to avoid accidental contact that could cause test interference. The connecting mechanism 2 connects the clamping plate 22 and the controller 21 through wires, and then connects to the tester 1.

[0035] As one implementation method, such as Figure 3 As shown, the connection mechanism 2 includes a conductive plate 23 and an insulating plate 24 stacked together. The conductive plate 23 is used for electrical connection with a lead-out terminal 514, and the insulating plate 24 is used to isolate another adjacent lead-out terminal 514 in the stacking direction T of the bare cell assembly 5. The conductive plate 23 (e.g., an aluminum plate) directly contacts the target lead-out terminal 514, while the insulating plate 24 (e.g., a ceramic plate) blocks adjacent lead-out terminal ears 514.

[0036] As one implementation method, such as Figure 1 As shown, the short-circuit test system also includes a cell pressing mechanism 3, which is used to press the cells 51 of the bare cell group 5 during the pressing test.

[0037] As one implementation method, such as Figure 1 As shown, the cell pressing mechanism 3 includes a cell pressing cylinder 31 and a cell pressing plate 32. Along the stacking direction T of the bare cell group 5, the cell pressing plate 32 is disposed on one side of the bare cell group 5, and the output end of the cell pressing cylinder 31 is connected to the cell pressing plate 32. Before testing, the bare cell assembly 5 is placed at the testing station. The cell pressing cylinder 31 applies pressure to the cell pressing plate 32. The cell pressing plate 32 presses the cell 51 from top to bottom along the stacking direction T to ensure that the cells 51 are tightly fitted together and to avoid misjudgment due to misalignment of the cells 51. As another implementation, the number of cell pressing cylinders 31 and cell pressing plates 32 can also be set to two. Along the stacking direction T, the two cell pressing plates 32 are respectively set on both sides of the bare cell assembly 5. The two cell pressing cylinders 31 are respectively connected to a corresponding cell pressing plate 32. The cell pressing cylinders 31 apply pressure to the cell pressing plate 32, and the two cell pressing plates 32 press the cell 51 from the upper and lower sides of the stacking direction T respectively.

[0038] As one implementation method, such as Figure 1As shown, the short-circuit test system also includes a tab pressing mechanism 4, which is used to press the lead terminals 514 of the bare cell assembly 5 during testing.

[0039] As one implementation method, such as Figure 1 As shown, the tab pressing mechanism 4 includes multiple tab pressing cylinders 41 and multiple tab pressing plates 42. Along the stacking direction T of the bare cell assembly 5, each tab pressing plate 42 is correspondingly disposed on the stacked lead-out terminals 514. The output end of one tab pressing cylinder 41 is connected to one tab pressing plate 42. Specifically, the tab pressing mechanism 4 includes four tab pressing cylinders 41 and four tab pressing plates 42. Tab pressing plates 42 are provided on both the upper and lower sides of the positive terminal 514A and the negative terminal 514B. One tab pressing cylinder 41 is connected to one tab pressing plate 42. During testing, pressure is applied to the tab pressing plates 42 by the tab pressing cylinders 41, causing the tab pressing plates 42 to press the lead-out terminals 514 from both sides of the cell stacking direction T, ensuring stable contact between the lead-out terminals 514 and the conductive surface 221 of the connecting mechanism 2, and reducing the influence of contact resistance on the test results.

[0040] As one implementation method, such as Figure 1 As shown, the short-circuit test system also includes a control system 6. The controller 21 is an electromagnetic switch, and the control system 6 is electrically connected to each electromagnetic switch. Furthermore, the tester 1, the two cell pressing cylinders 31, and the four tab pressing cylinders 41 are all electrically connected to the control system 6 to achieve intelligent control of the short-circuit test system.

[0041] Test procedure for bare cell short circuit test device:

[0042] Step 1: Place the bare cell assembly 5 at the testing station and press the electrode sheets together using the cell pressing mechanism 3;

[0043] Step 2: Press all the leads 514 together using the tab pressing mechanism 4, and ensure that each lead 514 is in contact with the conductive surface 221 of the corresponding connection mechanism 2;

[0044] Step 3: Select and close the switches of each branch, and use tester 1 to measure and determine if there is a short circuit.

[0045] This invention uses multiple connecting mechanisms 2 to connect the multiple leads 514 of the bare cell assembly 5 to be tested to the tester 1 one by one. By controlling the on and off of each connecting mechanism 2, the interconnection of each layer of cells 51 can be tested by controlling the tester 1. This not only detects whether the bare cell assembly 5 is short-circuited, but also determines which layer the short circuit occurs in, quickly and accurately pinpointing the short circuit point in which layer of the bare cell assembly 5, thus improving the accuracy and efficiency of short circuit testing of the bare cell assembly 5.

[0046] The following description, in conjunction with specific examples, provides further details.

[0047] Example: Figures 1 to 5 As shown, a bare cell assembly 5 with a structure of 6 positive layers and 7 negative layers is implemented as an example. The clamping plate 22 includes a conductive surface 221 and an insulating surface 222 arranged opposite to each other. For easy distinction, the clamping plate 22 is divided into a positive clamping plate (located on the positive terminal 514A side) and a negative clamping plate (located on the negative terminal 514B side).

[0048] In the stacking direction T, the order is as follows, from top to bottom:

[0049] Place the first positive electrode plate below the first positive terminal 514A, with the conductive surface 221 in contact with the first positive terminal 514A and the insulating surface 222 in contact with the second positive terminal 514A below it;

[0050] Place the second positive electrode clamp below the second positive terminal 514A, with the conductive surface 221 in contact with the second positive terminal 514A and the insulating surface 222 in contact with the third positive terminal 514A below it;

[0051] Similarly, the sixth positive electrode clamp is placed below the sixth positive electrode 514A, with the conductive surface 221 in contact with the sixth positive electrode 514A;

[0052] Place the first negative electrode clamp below the first negative terminal 514B, with the conductive surface 221 in contact with the first negative terminal 514B and the insulating surface 222 in contact with the second negative terminal 514B below.

[0053] Place the second negative electrode clamp below the second negative electrode 514B, with the conductive surface 221 in contact with the second negative electrode 514B and the insulating surface 222 in contact with the third negative electrode 514B below.

[0054] Similarly, the 7th negative electrode clamp is placed below the 7th negative electrode 514B, and the conductive surface 221 is in contact with the 7th negative electrode 514B.

[0055] The electrode clamping cylinder 41 is vented, so that the upper and lower electrode clamping plates 42 press the positive and negative leads 514 and clamping plates 22 with a pressure of 0.2 MPa.

[0056] The cell pressing cylinder 31 is ventilated, so that the upper and lower cell pressing plates 32 press the electrode plates at a pressure of 0.3 MPa.

[0057] The opening and closing of each controller 21 is controlled by the following method:

[0058] Method 1: Use the "binary search" principle to find the short-circuit point.

[0059] Step 1: Edit the following test procedure to find the number of positive short-circuit layers:

[0060]

[0061]

[0062] Step 2: Edit the following test procedure to find the negative short-circuit layer number, such as the marked "positive 2 short circuit" and "positive 4 short circuit" as examples:

[0063]

[0064] Step 3: Control system 6 collects the marking results and gives the conclusion:

[0065] (1) The second layer of the positive electrode and the first layer of the negative electrode are short-circuited;

[0066] (2) Short circuit between the fourth layer of the positive electrode and the fourth layer of the negative electrode;

[0067] (3) The positive electrode layer 4 and the negative electrode layer 5 are short-circuited.

[0068] Method 2: Use the "layer-by-layer detection" principle to find short circuit points.

[0069] Step 1: Edit the following test procedure to find the number of positive short-circuit layers:

[0070]

[0071]

[0072] Step 2: Edit the following test procedure to find the negative short-circuit layer number, such as the marked "positive 2 short circuit" and "positive 3 short circuit" as examples:

[0073]

[0074] Step 3: Control system 6 collects the marking results and gives the conclusion:

[0075] (1) The second layer of the positive electrode and the first layer of the negative electrode are short-circuited;

[0076] (2) The third layer of the positive electrode and the fourth layer of the negative electrode are short-circuited.

[0077] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content without departing from the scope of the technical solution of the present utility model. These are equivalent embodiments with equivalent changes. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A short-circuit testing system for bare battery cell assemblies, characterized in that, The device includes a tester (1) and multiple connection mechanisms (2). The tester (1) includes a positive detection terminal (11) and a negative detection terminal (12). The bare cell group (5) includes multiple stacked cells (51). Each cell (51) includes a lead-out terminal (514). The lead-out terminal (514) includes a positive terminal (514A) and a negative terminal (514B). The positive terminal (514A) of the multiple cells (51) is connected to the positive detection terminal (11) of the tester (1) through the multiple connection mechanisms (2). The negative terminal (514B) of the multiple cells (51) is connected to the negative detection terminal (12) of the tester (1) through the multiple connection mechanisms (2).

2. The short-circuit testing system for bare cell assemblies as described in claim 1, characterized in that, Each of the connecting mechanisms (2) is connected in series with a controller (21).

3. The short-circuit testing system for bare cell assemblies as described in claim 2, characterized in that, The controller (21) is a switch.

4. The short-circuit testing system for bare cell assemblies as described in claim 1, characterized in that, Along the stacking direction (T) of the bare cell assembly (5), the lead terminals (514) on the same side have the same polarity.

5. The short-circuit testing system for bare cell assemblies as described in claim 1, characterized in that, The connection mechanism (2) includes a clamp (22), which includes a conductive surface (221) and an insulating surface (222) disposed opposite to each other. The conductive surface (221) is used to electrically connect with any of the lead-out terminals (514), and the insulating surface (222) is used to isolate the other lead-out terminal (514) adjacent to it in the stacking direction (T) of the bare cell assembly (5).

6. The short-circuit testing system for bare cell assemblies as described in claim 1, characterized in that, The connection mechanism (2) includes a conductive plate (23) and an insulating plate (24) stacked together. The conductive plate (23) is used to electrically connect to one of the lead-out terminals (514), and the insulating plate (24) is used to isolate the bare battery cell assembly (5) from another lead-out terminal (514) adjacent to it in the stacking direction (T).

7. The short-circuit testing system for bare cell assemblies as described in claim 1, characterized in that, The short-circuit test system also includes a cell pressing mechanism (3), which is used to press the cells (51) of the bare cell group (5) during the test.

8. The short-circuit testing system for bare cell assemblies as described in claim 7, characterized in that, The cell pressing mechanism (3) includes a cell pressing cylinder (31) and a cell pressing plate (32). Along the stacking direction (T) of the bare cell group (5), the cell pressing plate (32) is disposed on one side of the bare cell group (5), and the output end of the cell pressing cylinder (31) is connected to the cell pressing plate (32).

9. The short-circuit testing system for bare cell assemblies as described in claim 1, characterized in that, The short-circuit test system also includes a tab pressing mechanism (4), which is used to press the lead-out terminal (514) during testing.

10. The short-circuit testing system for bare cell assemblies as described in claim 9, characterized in that, The tab pressing mechanism (4) includes multiple tab pressing cylinders (41) and multiple tab pressing plates (42). Along the stacking direction (T) of the bare cell assembly (5), multiple tab pressing plates (42) are correspondingly arranged on both sides of the stacked lead-out terminals (514). The output end of one tab pressing cylinder (41) is connected to one tab pressing plate (42).

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