Battery cell expansion test tool and expansion detection instrument

Abstract

The utility model provides a battery cell expansion test tool which comprises a first seat body and a second seat body which are detachably connected, a first placing groove and a second placing groove are formed in the first seat body and the second seat body respectively, and a placing cavity suitable for fixedly placing a battery cell is defined by the first placing groove and the second placing groove; a first clamping part suitable for clamping an upper tab of a battery cell and a second clamping part suitable for clamping a lower tab of the battery cell are respectively arranged at the upper end part and the lower end part of the placing cavity; and conductive circuits are arranged in the first seat body and the second seat body and are used for being electrically connected to a battery cell placed in the placement cavity through the first clamping part and the second clamping part. The utility model also provides an expansion detection instrument. According to the utility model, the expansion detection of the battery cell is more stable, and the test precision and accuracy are higher.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium battery detection, and in particular to a battery cell expansion test tool and an expansion detection instrument. Background Art

[0002] During the cycle of lithium-ion batteries, the positive and negative electrode materials will experience structural expansion due to the lithium insertion and extraction behavior, and the chemical reaction will also produce gas, resulting in gas expansion. The structural expansion of the electrode material and the gas expansion may cause a large volume deformation of the battery cell, thereby damaging the battery performance and causing battery safety hazards. Therefore, it is necessary to simulate the cycle of charge and discharge to perform expansion tests. Currently, most methods on the market are to directly perform expansion tests on the entire battery. However, since the conventional battery casing is made of steel, it has relatively large rigidity and is also relatively thick, the expansion of the battery cell is reflected inside and is not fully transmitted to the outside, making it difficult to accurately monitor and analyze the expansion force and expansion characteristics of the battery cell.

[0003] Currently, there are also jigs for directly testing battery cells, such as a new cylindrical battery cell expansion detection equipment with publication number CN212988304U. However, it has an open base and uses a probe-type displacement sensor. The battery cell is not fixed stably and the battery tabs have no clamping mechanism. When expansion occurs during cyclic charge and discharge testing, the cylindrical battery cell may undergo some expansion displacement (especially silicon-based battery cell materials with a large expansion rate), causing the contact point between the displacement sensor probe and the surface of the cylindrical battery cell to slip, or the electrical connection of the tabs to loosen, resulting in inaccurate measurement. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide a battery cell expansion test tool to solve the problem that the prior art is difficult to prevent the battery cell tabs from loosening and the battery cell is easily offset.

[0005] The utility model adopts the following scheme: the application provides a battery cell expansion test tool, including a first seat body and a second seat body that are detachably connected, a first placement groove and a second placement groove are respectively formed on the first seat body and the second seat body, the first placement groove and the second placement groove form a placement cavity suitable for fixedly placing the battery cell; the upper end and the lower end of the placement cavity are respectively provided with a first clamping portion suitable for clamping the upper pole ear of the battery cell and a second clamping portion suitable for clamping the lower pole ear of the battery cell, and a conductive circuit is provided in the first seat body and the second seat body for electrically connecting to the battery cell placed in the placement cavity through the first clamping portion and the second clamping portion.

[0006] Further, the first clamping portion includes a first conductive member and a first insulating member, wherein the first conductive member is arranged at the upper end of the first placement groove and is connected to the conductive circuit in the first seat body through the first conductor, and the first insulating member is arranged at the upper end of the second placement groove for pressing the upper pole ear onto the first conductive member.

[0007] Furthermore, the second clamping portion includes a second conductive member and a second insulating member, wherein the second conductive member is arranged at the lower end of the second placement groove and is connected to the conductive circuit in the second seat body through the second conductor, and the second insulating member is arranged at the lower end of the first placement groove for pressing the lower pole ear onto the second conductive member.

[0008] Furthermore, the first conductor and the second conductor are made of stainless steel.

[0009] Furthermore, the first insulating member and the second insulating member are made of plastic.

[0010] Furthermore, the first conductive member, the second insulating member and the first seat body are detachably connected, and the second conductive member, the first insulating member and the second seat body are detachably connected; the first conductive member and the first insulating member are provided with matching screw holes to achieve detachable connection, and the second conductive member and the second insulating member are provided with matching screw holes to achieve detachable connection.

[0011] Furthermore, the first placement groove and the second placement groove are arc-shaped grooves matching the battery core.

[0012] Furthermore, the battery cell is a cylindrical battery cell.

[0013] Furthermore, a surface of the first base body provided with the first placement groove is provided with a plurality of positioning columns, and a surface of the second base body provided with the second placement groove is provided with a plurality of positioning holes matching the positioning columns.

[0014] The utility model also provides an expansion detection instrument, comprising any one of the battery cell expansion test tools described above.

[0015] The beneficial effects of the utility model are as follows:

[0016] 1. A placement cavity for placing a battery cell is formed by setting two seats that can cooperate with each other, so that the battery cell in the placement cavity will not shift during testing, and accurate expansion measurement with small error during charging and discharging can be achieved; at the same time, a first clamping part and a second clamping part are set at the upper and lower ends of the placement cavity, and the upper and lower pole ears of the battery cell are fixed by the first clamping part and the second clamping part to avoid loosening due to expansion during testing and keep the current and voltage stable during measurement.

[0017] 2. The clamping part is composed of conductive parts and insulating parts in pairs, which effectively prevents short circuits. The upper and lower pole ears are electrically connected to the conductive circuit of the seat body through the first clamping part and the second clamping part.

[0018] 3. The conductive parts and insulating parts can be designed as a detachable structure, for example, connected by threads, which has a simple structure, is easy to install, and has a better clamping effect.

[0019] 4. The seat body is provided with a number of positioning columns and matching positioning holes to achieve a guiding function during docking. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the appearance structure of a battery expansion test tool according to an embodiment of the utility model;

[0021] Figure 2 It is a schematic cross-sectional structure diagram of a battery cell expansion test tooling according to an embodiment of the utility model;

[0022] Figure 3 This is a schematic diagram of the exploded structure of a battery cell expansion test tool according to an embodiment of the utility model;

[0023] Figure 4 It is a structural schematic diagram of the second seat body of a battery cell expansion testing tool according to an embodiment of the utility model; icons: first seat body 1, first placement groove 11, positioning column 12, first conductive member 13, second insulating member 14, first conductor 15, second seat body 2, positioning hole 20, second placement groove 21, first insulating member 22, second conductive member 23, second conductive member 24, battery cell 3, upper pole ear 31, lower pole ear 32, screw hole 40. DETAILED DESCRIPTION

[0024] Embodiment 1

[0025] Combination Figure 1 to Figure 2 As shown, this embodiment provides an expansion detection instrument, including a battery cell expansion test fixture. The battery cell expansion test fixture includes a first seat body 1 and a second seat body 2 that are detachably connected, and a first placement groove 11 and a second placement groove 21 are formed on the first seat body 1 and the second seat body 2, respectively, and the first placement groove 11 and the second placement groove 21 enclose a placement cavity suitable for fixedly placing the battery cell 3; the upper end and the lower end of the placement cavity are respectively provided with a first clamping portion suitable for clamping the upper pole ear 31 of the battery cell 3 and a second clamping portion suitable for clamping the lower pole ear 32 of the battery cell 3, and the first seat body 1 and the second seat body 2 are provided with a conductive circuit for electrically connecting to the battery cell 3 placed in the placement cavity through the first clamping portion and the second clamping portion.

[0026] The expansion detection instrument described herein includes a detection platform, a power structure and a pressure sensor. The battery cell 3 is coated with an aluminum-plastic film. The first seat 1 can be fixed on the detection platform. The power mechanism drives the pressure sensor to abut against the second seat 2, thereby detecting the expansion of the battery cell. In one embodiment, the expansion detection instrument described herein can refer to a new expansion tester with a publication number of CN213748386U.

[0027] The shape of the battery cell 3 is not specifically limited here. According to actual test conditions, it can be a cylindrical battery cell 3 or other shapes. The shapes of the first placement groove 11 and the second placement groove 21 are adjusted according to the shape of the battery cell 3 to match the shape of the battery cell 3. In this embodiment, a commonly used cylindrical battery cell 3 is taken as an example for description.

[0028] Combination Figure 2 As shown, in this embodiment, the first seat body 1 and the second seat body 2 are insulated and connected. When in use, the first seat body 1 and the second seat body 2 are mainly used in a flat up and down state, but can also be used in a left and right state. Specifically, the first seat body 1 is used to be placed on the detection platform and fixed on the detection platform, and includes a first placement groove 11, and the first placement groove 11 is used to place the cylindrical battery cell 3. The second seat body 2 is provided with a second placement groove 21 opposite to the first placement groove 11. The first placement groove 11 and the second placement groove 21 are arc grooves matching the cylindrical battery cell 3, and when the first seat body 1 and the second seat body 2 are tightly connected, the first placement groove 11 and the second placement groove 21 can form a placement cavity for placing the cylindrical battery cell 3, and the cylindrical battery cell 3 cannot rotate or move in the placement cavity. The side of the second seat body 2 facing away from the second placement groove 21 can be connected to a pressure sensor and a power structure, and the power mechanism controls the pressure sensor to be close to or away from the second seat body 2. A conductive circuit (not shown) is provided inside the first seat body 1 and the second seat body 2. The conductive circuit can be connected to a power source, and when a cylindrical battery cell 3 is placed in the placement cavity, the conductive circuit of the first seat body 1 and the second seat body 2 forms a circuit loop with the cylindrical battery cell 3, so that the expansion rate of the cylindrical battery cell 3 during the charging and discharging process can be detected. The conductive circuit here is a prior art and will not be elaborated in detail.

[0029] Continue to combine Figure 2As shown, in this embodiment, the first clamping portion includes a first conductive member 13 and a first insulating member 22, wherein the first conductive member 13 is disposed at the upper end of the first placement slot 11 and is connected to the conductive circuit in the first seat 1 through the first conductor 15, and the first insulating member 22 is disposed at the upper end of the second placement slot 21, and is used to press the upper pole ear 31 onto the first conductive member 13. The second clamping portion includes a second conductive member 23 and a second insulating member 14, wherein the second conductive member 23 is disposed at the lower end of the second placement slot 21 and is connected to the conductive circuit in the second seat 2 through the second conductor 24, and the second insulating member 14 is disposed at the lower end of the first placement slot 11, and is used to press the lower pole ear 32 onto the second conductive member 23.

[0030] In this embodiment, the first conductive member 13 is electrically connected to the conductive circuit through the first conductive body 15, and the second conductive member 23 is electrically connected to the conductive circuit through the second conductive body 24. Specifically, the first conductive member 13 and the second conductive member 23 are both provided with mounting grooves for mounting the first conductive body 15 and the second conductive body 24. When the first conductive member 13 and the second conductive member 23 are mounted to the first seat 1 and the second seat 2, the first conductive body 15 and the second conductive body 24 are mounted in the mounting grooves. During the connection process between the first seat 1 and the second seat 2, the first conductive body 15 and the second conductive body 24 remain stationary relative to the first seat 1 and the second seat 2, thereby making the electrical connection stable.

[0031] In one embodiment, the first conductor 15 and the second conductor 24 may be made of stainless steel or other metal conductive materials. The first insulating member 22 and the second insulating member 14 may be made of plastic material, such as PEEK material.

[0032] Embodiment 2

[0033] This embodiment is basically the same as the first embodiment, except that:

[0034] Combination Figure 3 and Figure 4 As shown, the first conductive member 13, the second insulating member 14 and the first base body 1 are detachably connected, and the second conductive member 23, the first insulating member 22 and the second base body 2 are detachably connected. The first conductive member and the first insulating member are provided with matching screw holes 40 to achieve detachable connection, and the second conductive member and the second insulating member are also provided with matching screw holes 40 to achieve detachable connection.

[0035] During assembly, first install the first conductive member 13 and the second insulating member 14 in the grooves at the upper and lower ends of the first placement groove 11, respectively, and then place the battery cell 3 in the first placement groove 11, so that the upper pole ear 31 of the battery cell 3 is located above the first conductive member 13, and the lower pole ear 32 is located above the second insulating member 14; then, the first insulating member 22 and the second conductive member 23 are respectively fixed to the first conductive member 13 and the second insulating member 14 by threaded connection through matching screw holes 40, clamp the upper and lower pole ears of the battery cell 3, and then press the second seat body 2 as a whole against the first seat body 1. The upper pole ear 31 and the lower pole ear 32 are fixed by surface connection, and are electrically connected to the first conductive member 13 and the second conductive member 23 by surface contact. The connection structure is relatively stable, which effectively prevents the problem of loosening during the expansion test and causing power failure.

[0036] Combination Figure 3 and Figure 4 As shown, in this embodiment, a first seat body 1 is provided with a first placement groove 11 on one side thereof and is provided with a plurality of positioning columns 12, and a second seat body 2 is provided with a second placement groove 21 on one side thereof and is provided with a plurality of positioning holes 20 matching the positioning columns 12, so as to facilitate quick and accurate docking when the second seat body 2 is connected to the first seat body 1.

[0037] Each embodiment of the utility model effectively improves the accuracy and stability of the test. When performing an expansion test, the battery cell 3 is first packaged with an aluminum-plastic film, and the aluminum-plastic film is punched and cut into a bag shape. The battery cell 3 is placed in the bag, closed and pressed to complete the packaging, and dried and tested for flatness. The packaged battery cell 3 is then placed in an expansion test tooling and assembled, moved to the expansion detector platform, and powered on for charging and discharging to test the expansion force. The utility model is particularly suitable for testing battery cells in cylindrical shapes.

[0038] It should be understood that the above are only preferred implementations of the present utility model, and the protection scope of the present utility model is not limited to the above embodiments. All technical solutions under the concept of the present utility model belong to the protection scope of the present utility model.

[0039] The above description of the drawings used in the implementation manner only shows certain embodiments of the utility model and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

Claims

1. A battery cell expansion test fixture, comprising a first seat body and a second seat body that are detachably connected, characterized in that: A first placement groove and a second placement groove are respectively formed on the first seat body and the second seat body, and the first placement groove and the second placement groove form a placement cavity suitable for fixedly placing the battery cell; the upper end and the lower end of the placement cavity are respectively provided with a first clamping portion suitable for clamping the upper pole ear of the battery cell and a second clamping portion suitable for clamping the lower pole ear of the battery cell, and a conductive circuit is provided in the first seat body and the second seat body for electrically connecting to the battery cell placed in the placement cavity through the first clamping portion and the second clamping portion.

2. The battery cell expansion test fixture according to claim 1, characterized in that: The first clamping portion includes a first conductive member and a first insulating member, wherein the first conductive member is arranged at the upper end of the first placement groove and is connected to the conductive circuit in the first seat body through the first conductor, and the first insulating member is arranged at the upper end of the second placement groove and is used to press the upper pole ear onto the first conductive member.

3. The battery cell expansion test fixture according to claim 2, characterized in that: The second clamping portion includes a second conductive member and a second insulating member, wherein the second conductive member is arranged at the lower end of the second placement groove and is connected to the conductive circuit in the second seat body through the second conductor, and the second insulating member is arranged at the lower end of the first placement groove and is used to press the lower pole ear onto the second conductive member.

4. The battery cell expansion test fixture according to claim 3, characterized in that: The first conductor and the second conductor are made of stainless steel.

5. The battery cell expansion test fixture according to claim 3, characterized in that: The first insulating member and the second insulating member are made of plastic.

6. The battery cell expansion test fixture according to claim 3, characterized in that: The first conductive member, the second insulating member and the first seat are detachably connected, and the second conductive member, the first insulating member and the second seat are detachably connected; the first conductive member and the first insulating member are provided with matching screw holes to achieve detachable connection, and the second conductive member and the second insulating member are provided with matching screw holes to achieve detachable connection.

7. The battery cell expansion test fixture according to claim 1, characterized in that: The first placement groove and the second placement groove are arc-shaped grooves matching the battery core.

8. The battery cell expansion test fixture according to claim 1, characterized in that: The battery cell is a cylindrical battery cell.

9. The battery cell expansion test fixture according to claim 1, characterized in that: A surface of the first base body provided with the first placement groove is provided with a plurality of positioning columns, and a surface of the second base body provided with the second placement groove is provided with a plurality of positioning holes matching with the positioning columns.

10. An expansion detection instrument, characterized in that: A battery cell expansion test tool comprising the battery cell expansion test tool as described in any one of claims 1 to 9.

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