Method for testing internal temperature rise of lithium ion cell

Abstract

The invention relates to the technical field of new energy lithium ion battery testing, in particular to a method for testing internal temperature rise of a lithium ion cell, a to-be-tested cell is tested through a testing device, and the testing method comprises the following steps: selecting four high-precision thermocouple temperature measuring lines, and making marks a, b, c and d; thermocouple temperature measuring lines a, b, c and d are respectively arranged on the large surfaces of the naked battery cells, in the middle of a single naked battery cell, between two naked battery cells and in a top cover welding adapter sheet area; installing a thermocouple temperature measuring line on an insulating tube, leading out the thermocouple temperature measuring line from an anti-explosion valve, connecting a multi-path thermodetector, and sealing an opening of the anti-explosion valve with AB glue to obtain a sealed target battery; and carrying out charging and discharging treatment on the sealed target battery. According to the method, the temperature rise of each position in the battery cell is detected, and a high-precision thermocouple wire is arranged in the roll core, is led out from an anti-explosion valve and is connected with a multi-channel temperature detector, so that the real temperature rise in the battery cell under different working conditions is detected.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy lithium-ion battery testing, and in particular to a method for testing the internal temperature rise of a lithium-ion battery cell. Background Art

[0002] Temperature has a significant impact on lithium-ion batteries. Too low a temperature will cause lithium deposition at the negative electrode, while too high a temperature will not only cause changes in the battery capacity, but will also damage the battery and reduce its service life. In addition, during the use of lithium-ion batteries, due to differences in cell materials, formulations, structural design, and operating conditions, the heat generated by the battery under different test conditions varies greatly; therefore, the temperature rise of the cell has always been one of the key parameters of the cell; studying the heat generation and heat dissipation performance of the battery plays a very important guiding role in the safe use of the battery, and is also of great significance to the optimal design of the battery structure and health management.

[0003] At present, the traditional test is still to collect temperature by fixing sensors on the outside of the battery cell, such as the large surface of the battery cell, the positive and negative poles, etc.; however, this method is greatly affected by external factors. For example, the internal resistance of the positive and negative pole welding is too large, which will cause abnormal temperature collection; in addition, this test method cannot simulate the actual heat generation inside the battery cell when the battery cell is in the charging and discharging state.

[0004] Based on this, a method for testing the internal temperature rise of a lithium-ion battery cell is now provided, which can eliminate the disadvantages of the existing device. Summary of the invention

[0005] In view of the above problems, a method for testing the internal temperature rise of a lithium-ion battery cell is provided, which solves the problem of abnormal temperature collection caused by excessive influence of external factors through an efficient, accurate and economical method.

[0006] In order to solve the problems in the prior art, the present invention provides a method for testing the internal temperature rise of a lithium-ion battery cell, wherein a testing device is used to test the battery cell to be tested.

[0007] The testing method includes the following steps: S1: selecting four high-precision thermocouple temperature measuring wires and marking them as a, b, c, and d; S2: arranging the thermocouple temperature measuring wires a, b, c, and d on the large surface of the bare battery cell, the middle of a single bare battery cell, between two bare battery cells, and the top cover welding adapter area, respectively; S3: installing insulating tubes on the thermocouple temperature measuring wires, leading them out from the explosion-proof valve, connecting them to a multi-channel temperature measuring instrument, and sealing the opening of the explosion-proof valve with AB glue to obtain a sealed target battery; S4: performing charge and discharge treatment on the sealed target battery.

[0008] Preferably, the testing device includes a battery cell and a charge and discharge tester and a multi-channel temperature measuring instrument arranged on one side of the battery cell.

[0009] Preferably, the battery core is electrically connected to the multi-channel temperature measuring instrument via a thermocouple temperature measuring line.

[0010] Preferably, an insulating tube is provided on the outer side of the thermocouple temperature measuring line close to one end of the charge and discharge tester.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The present invention uses an efficient, accurate and economical method to detect the temperature rise at various locations inside the battery cell. During the battery cell manufacturing process, a high-precision thermocouple wire is arranged inside the winding core, led out from the explosion-proof valve, and connected to a multi-channel temperature detector to detect the actual internal temperature rise of the battery cell under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a method to test the internal temperature rise of lithium-ion batteries. The temperature rise of 200Ah at different powers (0.5P / 1.0P) is shown. Figure 1 .

[0014] Figure 2 This is a method to test the internal temperature rise of lithium-ion batteries. The temperature rise of 200Ah at different powers (0.5P / 1.0P) is shown. Figure 2 .

[0015] Figure 3 The invention discloses a method for testing the internal temperature rise of a lithium-ion battery cell and an arrangement diagram of thermocouple temperature measurement lines inside the coil core.

[0016] Figure 4 The present invention is a temperature rise test schematic diagram of a method for testing the internal temperature rise of a lithium-ion battery cell.

[0017] The numbers in the figure are: 1. Charge and discharge tester; 2. Battery cell; 3. Insulation tube; 4. Multi-channel temperature measuring instrument; 5. Thermocouple temperature measuring line; 6. Center of large surface of winding core; 7. Center of single winding core; 8. Center of two winding cores. DETAILED DESCRIPTION

[0018] In order to further understand the features, technical means, specific objectives and functions of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0019] This embodiment provides a method for testing the internal temperature rise of a lithium-ion battery cell, wherein a testing device is used to test a battery cell 2 to be tested.

[0020] The test method includes the following steps:

[0021] S1: Select four high-precision thermocouple temperature measuring wires 5 and mark them as a, b, c, and d;

[0022] S2: Arrange the thermocouple temperature measuring lines 5a, b, c, d on the large surface of the bare battery cell 2, the middle of a single bare battery cell 2, between two bare battery cells 2, and the top cover welding adapter area respectively;

[0023] S3: Install the thermocouple temperature measuring line 5 on the insulating tube 3, lead it out from the explosion-proof valve, connect it to the multi-channel temperature measuring instrument 4, and seal the opening of the explosion-proof valve with AB glue to obtain the sealed target battery;

[0024] S4: performing charge and discharge processing on the sealed target battery.

[0025] Specifically, the test device mentioned above includes a battery cell 2 and a charge and discharge tester 1 and a multi-channel temperature measuring instrument 4 arranged on one side of the battery cell 2 .

[0026] Furthermore, the battery core 2 is electrically connected to the multi-channel temperature measuring instrument 4 via a thermocouple temperature measuring line 5 .

[0027] Furthermore, an insulating tube 3 is provided on the outer side of the thermocouple temperature measuring wire 5 close to one end of the charge and discharge tester 1 .

[0028] According to the principles of this aspect, the specific cases are as follows:

[0029] This case mainly selects a square aluminum shell 200Ah battery cell with multiple tabs as the target to test the temperature rise difference at different positions inside the battery cell 2;

[0030] (1) Select three K-type thermocouple temperature measuring wires 5 and insulate the probes and wire harnesses.

[0031] (2) During the production of the battery cell 2, the thermocouple temperature measuring line 5 is placed at the center 6 of the large surface of the winding core, the center 7 of the single winding core, and the center 8 of the two winding cores; as follows Figure 1-Figure 3 As shown;

[0032] (3) Assemble the battery core 2, lead the thermocouple temperature measuring line 5 out from the explosion-proof valve, and seal the insulating tube 3 with AB glue;

[0033] (4) Connect the thermocouple temperature measuring line 5 to the multi-channel temperature measuring instrument 4, monitor the temperature rise of the large surface of the battery at the same time, and perform charge and discharge tests on the battery cell 2; as follows Figure 2 As shown;

[0034] (5) This experiment mainly tests the temperature rise of 200Ah battery cells at different rates (0.5P, 1.0P); the test results and data processing are as follows Figure 1-Figure 4 shown.

[0035] The above embodiments only express one or several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A method for testing the internal temperature rise of a lithium-ion battery cell, characterized in that: The battery cell (2) to be tested is tested by a testing device, The test method includes the following steps: S1: Select four high-precision thermocouple temperature measuring wires (5) and mark them as a, b, c, and d; S2: Arrange the thermocouple temperature measuring wires (5) a, b, c, d respectively on the large surface of the bare battery cell (2), the middle of a single bare battery cell (2), between two bare battery cells (2), and in the area of ​​the top cover welding adapter; S3: Install the thermocouple temperature measuring line (5) on the insulating tube (3), lead it out from the explosion-proof valve, connect it to the multi-channel temperature measuring instrument (4), and seal the opening of the explosion-proof valve with AB glue to obtain a sealed target battery; S4: performing charge and discharge processing on the sealed target battery.

2. A method for testing the internal temperature rise of a lithium-ion battery cell according to claim 1, characterized in that: The testing device comprises a battery cell (2), and a charge and discharge testing machine (1) and a multi-channel temperature measuring instrument (4) arranged on one side of the battery cell (2).

3. A method for testing the internal temperature rise of a lithium-ion battery according to claim 2, characterized in that: The battery core (2) is electrically connected to the multi-channel temperature measuring instrument (4) via a thermocouple temperature measuring line (5).

4. A method for testing the internal temperature rise of a lithium-ion battery cell according to claim 2, characterized in that: An insulating tube (3) is provided on the outer side of the thermocouple temperature measuring wire (5) close to one end of the charge and discharge tester (1).

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