CN108802617B - Test method for semi-finished battery cell - Google Patents

Abstract

The invention discloses a method for testing a semi-finished product of a battery core. And when the voltage difference between the first conducting part and the second conducting part of the semi-finished product of the battery cell is smaller than the voltage threshold value, the semi-finished product of the battery cell is charged with constant current. When the voltage difference between the first connecting part and the second connecting part is larger than or equal to the voltage threshold value, the semi-finished product of the battery core is charged with constant voltage. And after the preset time interval for starting charging, acquiring the total electric quantity for charging the semi-finished product of the battery core at constant current in the preset time interval. And judging whether the total electric quantity is larger than the electric quantity threshold value. And when the total electric quantity is greater than the electric quantity threshold value, judging that the insulation degree of the semi-finished product of the battery core is poor.

Description

Test method for semi-finished battery cell

technical field

The present invention relates to a method for testing semi-finished products of battery cells, in particular to a method for testing semi-finished products of battery cells for testing the insulation degree of semi-finished products of battery cells.

Background technique

In recent years, the electronic industry has developed vigorously, and various electronic devices have become quite popular. For the manufacture of various portable electronic devices, the most important thing is the miniaturization of the volume and the reduction of the weight. In order to provide the convenience of carrying electrical appliances and reduce the restriction on the supply of electrical energy by the external environment, the battery has become an extremely common electrical energy storage device to provide electrical energy at any time.

Most of today's portable electronic devices mainly use reusable lithium-ion secondary batteries with large capacity and high energy density. The lithium battery is mainly composed of a plurality of positive electrode sheets, negative electrode sheets and separators to form a semi-finished battery cell, and then the electrolyte is injected into the battery core to make the finished lithium battery. Under such a structure, the distance between the positive and negative electrodes of the battery cell is quite important. At present, the distance between the positive and negative electrodes of the battery cell is mainly extended by the separator. However, in the manufacturing process, there may be a short circuit due to insufficient local distance between the two poles due to material cutting burrs, foreign objects flying in during the winding process, or uneven thickness of the material.

In the manufacturing process, although the insulation level of the battery cells will be tested, the insulation effect is mainly confirmed by a long-term continuous withstand voltage test (Hi-pot Test). Such a test method requires a long energy conversion time, and the capacitance error of the object to be tested is not small (±20%), which is likely to cause misjudgment. In addition, the order of magnitude difference between the steady-state voltage of the semi-finished battery cell and the voltage discharged during the charging process is not large, and there is a possibility that it cannot be discriminated.

SUMMARY OF THE INVENTION

The present invention provides a method for testing semi-finished products of battery cells, so as to overcome the problems of long testing time, easy misjudgment or inability to identify defects in the traditional testing methods for semi-finished products of battery cells.

The invention discloses a method for testing semi-finished products of battery cores, and the method for testing semi-finished products of battery cores is suitable for semi-finished products of battery cores. The semi-finished battery cell includes a first electrode and a second electrode. A first electrode and a second electrode are alternately stacked. An insulating layer is disposed between a first electrode and a second electrode. A first electrode is connected to the first conductive portion, and a second electrode is connected to the second conductive portion. In the battery cell semi-finished product testing method, when the voltage difference between the first conducting portion and the second conducting portion is less than a voltage threshold, the battery cell semi-finished product is charged with a constant current. When the voltage difference between the first conducting portion and the second conducting portion is greater than or equal to a voltage threshold, the semi-finished battery cell is charged with a constant voltage. After the preset time interval for starting charging, the total amount of electricity charged to the semi-finished battery cell with a constant current in the preset time interval is obtained. Determine whether the total power is greater than the power threshold. When the total power is greater than the power threshold, it is judged that the insulation degree of the semi-finished battery cell is poor.

In view of the above, the present invention proposes a method for testing semi-finished battery cells, by judging whether the total charge amount of the semi-finished battery cells charged with a constant current is greater than the power threshold value, so as to determine whether the insulation degree of the semi-finished battery cells meets the requirements. In this way, in addition to saving testing time, it also provides a quantitative analysis method.

Description of drawings

FIG. 1A is a schematic structural diagram of an ideal semi-finished battery cell according to an embodiment of the present invention.

FIG. 1B is a schematic structural diagram of a defective semi-finished battery cell according to an embodiment of the present invention.

2A is a schematic diagram of a voltage difference when charging an ideal semi-finished battery cell according to an embodiment of the present invention.

FIG. 2B is a schematic diagram of the voltage difference when charging a non-ideal semi-finished battery cell according to an embodiment of the present invention.

2C is a schematic diagram of a voltage difference when charging a non-ideal semi-finished battery cell according to another embodiment of the present invention.

3 is a method flowchart of a method for testing a semi-finished battery cell according to an embodiment of the present invention.

4A is a schematic diagram of the total power consumed by charging an ideal semi-finished battery cell with a constant current according to the embodiment corresponding to FIG. 2A .

FIG. 4B is a schematic diagram of the total power consumed by charging a semi-finished battery cell with a constant current according to the embodiment corresponding to FIG. 2B .

FIG. 4C is a schematic diagram of the total amount of power consumed by charging a semi-finished battery cell with a constant current according to the embodiment corresponding to FIG. 2C .

FIG. 5 is a method flow chart of some steps of a method for testing a semi-finished battery cell according to another embodiment of the present invention.

6 is a schematic diagram of a voltage difference when charging a semi-finished battery cell according to another embodiment of the present invention.

FIG. 7 is a method flow chart of some steps of a method for testing a semi-finished battery cell according to another embodiment of the present invention.

Among them, reference numerals:

10 semi-finished battery cells

C1 first lead

C2 second lead

CC, CCI, CC1, CC2, CC2’ current charging interval

CV, CVI, CV1, CV2, CV2’ voltage charging range

E1a, E1b, E1c, E1d, E1e First electrode

E2a, E2b, E2c, E2d Second electrode

ti, t1, t2, t3, t4 time points

Tdef1, Tdef2, Tdef3, Tdef3’, Tdef3” preset time interval

Tref reference time interval

Ttest actual test interval

Vth voltage threshold

Detailed ways

The detailed features and advantages of the present invention are described in detail in the following embodiments, and the content is sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the scope of the patent application and the drawings , any person skilled in the art can easily understand the related objects and advantages of the present invention. The following examples further illustrate the concept of the present invention in further detail, but are not intended to limit the scope of the present invention in any way.

The present invention provides a method for testing semi-finished products of battery cores, and the method for testing semi-finished products of battery cores is suitable for semi-finished products of battery cores. Please refer to FIG. 1A for a brief description of the semi-finished battery cell. FIG. 1A is a schematic structural diagram of the semi-finished battery cell according to an embodiment of the present invention. A battery cell semi-finished product 10 has a first electrode and a second electrode. In the embodiment shown in FIG. 1 , the first electrodes E1a, E1b, E1c, E1d, E1e and the second electrodes E2a, E2b, E2c, E2d are taken as examples for description, but the number of the first electrodes and the second electrodes is not the same Not limited to this. In practice, an insulating layer is disposed between the first electrode and the second electrode to isolate the first electrode and the second electrode. However, for the sake of simplicity and comprehension of the drawings, the insulating layer is not repeated here.

The first electrodes E1a, E1b, E1c, E1d, E1e of the semi-finished battery cell 10 are connected to the first conductive portion C1, and the second electrodes E2a, E2b, E2c, E2d are connected to the second conductive portion C2. In practice, the first conducting portion C1 and the second conducting portion C2 are, for example, made of conductive materials, and the first conducting portion C1 and the second conducting portion C2 are, for example, clamped, welded, or otherwise. connected to each of the first electrodes or the second electrodes. In other words, the first electrodes E1a, E1b, E1c, E1d, E1e are electrically connected to each other through the first conductive portion C1, and the second electrodes E2a, E2b, E2c, E2d are electrically connected to each other through the second conductive portion C2 connect. The first electrodes E1a, E1b, E1c, E1d, E1e are, for example, one of the anode or the cathode of the battery, and the second electrodes E2a, E2b, E2c, E2d are, for example, the other of the anode or the cathode of the battery.

Ideally, the structure of the semi-finished battery cell should be as shown in FIG. 1A , that is, the first electrodes and the second electrodes of the semi-finished battery cell are not in contact with each other, or the first electrodes E1a, E1b, E1c, E1d, There is no short circuit between any one of E1e and any one of the second electrodes E2a, E2b, E2c, and E2d. However, in practice, some of the first electrodes and some of the second electrodes of the semi-finished battery cell may be short-circuited during the manufacturing process due to material burrs, uneven thickness of the insulating layer, or foreign matter. Please refer to FIG. 1B to illustrate an example of a non-ideal semi-finished battery cell. FIG. 1B is a schematic structural diagram of a defective semi-finished battery cell according to an embodiment of the present invention. The structure of the semi-finished battery cell 10' is substantially similar to the structure of the semi-finished battery cell 10 . The difference from FIG. 1A is that foreign matter P exists in the structure of the semi-finished battery cell 10'. The foreign matter P is located between the first electrode E1b and the second electrode E2b of the semi-finished battery cell 10'. The foreign matter P contacts the first electrode E1b and the second electrode E2b, so that the first electrode E1b and the second electrode E2b are short-circuited.

In practice, according to the current physical conditions, it is possible for the foreign object P to move randomly. Therefore, the start time, duration and conduction degree of the short circuit between the first electrode E1b and the second electrode E2b vary depending on the material and size of the foreign object P or the contact with the electrodes. That is to say, even if there are foreign objects in the structure of the semi-finished battery cell, the foreign objects may not always cause a short circuit, and the relative time of each short circuit is not necessarily the same. Therefore, in practice, there is an urgent need for a testing method for semi-finished battery cells to identify the degree of insulation of semi-finished battery cells, and even to quantify the degree of insulation of semi-finished battery cells. In the following, the battery cell semi-finished product 10 is used to represent the ideal battery cell semi-finished product, and the battery cell semi-finished product 10' is used to represent the non-ideal battery cell semi-finished product for description.

Please refer to FIG. 2A to describe the situation of charging an ideal battery cell semi-finished product. FIG. 2A is a schematic diagram of the voltage difference when charging the battery cell semi-finished product 10 according to an embodiment of the present invention. More specifically, FIG. 2A is used to illustrate the change in the voltage difference between the first conducting portion C1 and the second conducting portion C2 when charging the battery cell semi-finished product 10 , or in other words, the voltage difference between any first electrode and any one voltage difference between the second electrodes. The horizontal axis in FIG. 2A is time, and the vertical axis is the voltage value of the voltage difference. FIG. 2A defines a constant current charging interval CCI and a constant voltage charging interval CVI. Literally, in the constant current charging interval CCI, the semi-finished battery cell 10 is charged with a constant current. In the constant voltage charging interval CVI, the battery cell semi-finished product 10 is charged with a constant voltage.

In the embodiment shown in FIG. 2A , the semi-finished battery cell 10 is charged first with a constant current. When the voltage difference is greater than or equal to the voltage threshold value Vth, the semi-finished battery cell 10 is charged with a constant voltage instead. In this embodiment, the voltage difference of the cell semi-finished product 10 is charged to the voltage threshold at the time point ti. Therefore, before the time point ti is the constant current charging interval CCI, and after the time point ti is the constant voltage charging interval CVI. Corresponding to different charging methods, the part where the voltage difference of the semi-finished battery cell 10 is in the constant current charging interval CCI is a slope with a fixed slope, and the part where the voltage difference of the semi-finished battery cell 10 is in the constant voltage charging interval CVI is a slope of 0 horizontal line.

Please refer to FIG. 2B again to illustrate the situation of charging a non-ideal semi-finished battery cell. FIG. 2B is a schematic diagram of the voltage difference when charging the semi-finished battery cell 10' according to an embodiment of the present invention. In FIG. 2B, ideal and non-ideal conditions are simultaneously depicted, wherein the voltage difference of the semi-finished battery cell 10' is represented by a thick line, and the voltage difference of the semi-finished battery cell 10 is represented by a thin line for comparison. The voltage difference of the semi-finished battery cell 10 in FIG. 2B is the voltage difference of the semi-finished battery cell 10 in FIG. 2A . Corresponding to the voltage difference of the semi-finished battery cell 10', FIG. 2B further defines a constant current charging interval CC1 and a constant voltage charging interval CV1. Before the time point t2 is the constant current charging section CC1, and after the time point t2 is the constant voltage charging section CV1.

In the embodiment shown in FIG. 2B , the semi-finished battery cell 10' is first charged with a constant current. In the embodiment shown in FIG. 2B , a short circuit situation temporarily occurs at time point t1 . Among them, the time point t1 precedes the time point ti. Therefore, before the time point t1, the voltage difference of the semi-finished battery cell 10' increases at a constant voltage increase rate (a constant slope in the figure). However, when the structure of the semi-finished battery cell 10 ′ is short-circuited as shown in FIG. 1B at the time point t1 , while the semi-finished battery cell 10 ′ is charged with a constant current, some electrodes of the semi-finished battery cell 10 ′ are not It is discharged normally, so that the voltage difference of the semi-finished battery cell 10 ′ drops rapidly at the time point t1 . After the time point t1, the short-circuit situation is eliminated due to the actual physical conditions, and the voltage difference of the battery cell semi-finished product 10' charged with a constant current increases again at a constant voltage increase rate. Until the time point t2, the voltage difference of the semi-finished battery cell 10' is charged to the voltage threshold value Vth. At this time, the semi-finished battery cell 10' is charged with a constant voltage.

Please refer to FIG. 2C again to illustrate another case of charging the non-ideal battery cell semi-finished product. FIG. 2C is a schematic diagram of the voltage difference when charging the non-ideal battery cell semi-finished product according to another embodiment of the present invention. In FIG. 2C , ideal and non-ideal conditions are also shown, wherein the voltage difference of the semi-finished battery cell 10 ′ is represented by a thick line, and the voltage difference of the semi-finished battery cell 10 is represented by a thin line. In FIG. 2C , the voltage difference corresponding to the semi-finished battery cell 10 ′ is defined as constant current charging interval CC2 , CC2 ′ and constant voltage charging interval CV2 , CV2 ′, the constant current charging interval CC2 is prior to the constant voltage charging interval CV2 , and the constant voltage The charging interval CV2 precedes the constant current charging interval CC2', and the constant current charging interval CC2' precedes the constant voltage charging interval CV2'. The constant current charging interval CC2 is located before the time point ti on the time axis, the constant voltage charging interval CV2 is located between the time point ti and the time point t3 on the time axis, and the constant current charging interval CC2' is located between the time point t3 and the time point t3 on the time axis. Between the time points t4, the constant voltage charging section CV2' is located after the time point t4 on the time axis.

In the embodiment shown in FIG. 2C, the voltage difference of the battery cell semi-finished product 10' is charged to the voltage threshold Vth at the time point ti. The short-circuit situation occurs at time point t3, which is located after time point ti on the time axis. The voltage difference of the battery cell semi-finished product 10' drops rapidly at the time point t3. Since the voltage difference of the semi-finished battery cell 10' is smaller than the voltage threshold value Vth after the time point t3, the semi-finished battery cell 10' is charged again with a constant current. After the time point t3, the short-circuit situation is temporarily eliminated due to the actual physical conditions, so the voltage difference of the semi-finished battery cells 10' charged with a constant current increases again at a constant voltage increase rate. Until the time point t4, the voltage difference of the semi-finished battery cell 10' is not charged to the voltage threshold value Vth again. At this time, the semi-finished battery cell 10' is charged again with a constant voltage.

In view of the above situation, the present invention provides a method for testing semi-finished battery cells to detect non-ideal semi-finished battery cells. Please refer to FIG. 2 to illustrate the method for testing semi-finished batteries provided by the present invention. A method flowchart of a method for testing a semi-finished product of a battery cell according to an embodiment of the present invention. As shown in FIG. 3 , in step S101 , when the voltage difference between the first conducting portion and the second conducting portion is less than a voltage threshold, the semi-finished battery cell is charged with a constant current. In step S103, when the voltage difference between the first conducting portion and the second conducting portion is greater than or equal to the voltage threshold, the semi-finished battery cell is charged with a constant voltage. In step S105, after the preset time interval for starting charging, the total amount of electricity charged to the semi-finished battery cell with a constant current in the preset time interval is obtained. In step S107, it is determined whether the total power is greater than the power threshold. In step S109, when the total power is greater than the power threshold, it is determined that the insulation degree of the semi-finished battery cell is poor. The battery cell semi-finished product testing method provided by the present invention can test the short-circuit situation of the battery cell semi-finished product at different times, and give a quantitative index. The different situations are described below.

Please refer to FIG. 4A . FIG. 4A is a schematic diagram of a charging current for charging an ideal semi-finished battery cell with a constant current according to the embodiment corresponding to FIG. 2A . The horizontal axis in FIG. 4A is time, the vertical axis is current, and a preset time interval Tdef1 is marked in FIG. 4A . Referring to step S105 of the battery cell semi-finished product testing method, in the embodiment shown in FIG. 4A , after the preset time interval Tdef1 of starting charging, the total amount of charging the battery cell semi-finished product with a constant current in the preset time interval Tdef1 is obtained. power. In practice, the area under the current curve is the total amount of electricity consumed when charging the semi-finished battery cell 10 with a constant current. In other words, when the preset time interval Tdef1 is set to be not less than the aforementioned constant current charging interval CCI, the total amount of charge for charging the semi-finished battery cell can be obtained according to the current IC and time parameters. In practice, the actual total power can be obtained by integrating the current and time. Alternatively, when the charging current value is known, the total time for charging the semi-finished battery cell 10 with a constant current can be counted, and then the total amount of electricity can be obtained according to the charging current value and the total time.

Please refer to FIG. 4B again. FIG. 4B is a schematic diagram of a charging current for charging a semi-finished battery cell with a constant current according to the embodiment corresponding to FIG. 2B . Similar to FIG. 2B , in FIG. 4B , the ideal conditions are represented by thin lines, and the non-ideal conditions are represented by thick lines. On the other hand, a predetermined time interval Tdef2 is marked in FIG. 4B . As mentioned above, since the semi-finished battery cell 10' is abnormally discharged at the time point t1, the time point T1 is located before the time point ti on the time axis, so that the constant current charging interval CC1 is longer than the constant current charging interval CCI. Therefore, the area under the thick line is larger than the area under the thin line, that is, the total power consumed by charging with a constant current under non-ideal conditions is greater than the total power consumed by charging with a constant current under ideal conditions. Therefore, referring to steps S107 and S109 of the semi-finished battery cell testing method, when the total power consumed by the current charging at a constant current is obtained, the total power is compared with a power threshold. When the total power is greater than the power threshold, it means that the total power is greater than the power consumed by charging an ideal battery cell semi-finished product with a constant current. At this time, it is judged that the insulation degree of the battery cell semi-finished product is poor.

In one embodiment, the preset time interval Tdef2 covers a part of the time interval during which the semi-finished battery cell is charged with a constant voltage. That is to say, in the embodiment shown in FIG. 4B , after a period of time when the constant current charging is switched to the constant voltage charging, the total electricity consumed by the constant current charging is started to be counted. In another embodiment, when switching from constant current charging to constant voltage charging, a related test circuit is triggered to count the total power consumed by constant current charging.

Please also refer to FIG. 4C . FIG. 4C is a schematic diagram of the total power consumed by charging the semi-finished battery cell with a constant current according to the embodiment corresponding to FIG. 2C . As shown in FIG. 4C , the regions under the current curve of charging the semi-finished battery cell 10' with a constant current can be respectively defined as region a1 and region a2. The sum of the area of the area a1 and the area of the area a2 is the total amount of electricity consumed by charging the semi-finished battery cell 10' with a constant current. In one embodiment, in the method for testing the semi-finished product of a battery cell provided by the present invention, for example, after the time point T4, all the total power consumed by charging with a constant current before the time point T4 can be counted, which is equivalent to the area of the area a1 and The sum of the areas of the area a2 is determined. From another perspective, it is equivalent to counting all the total power consumed by charging with a constant current in the preset time interval Tdef3. In another embodiment, for example, each time the constant current charging is switched to the constant voltage charging, statistics and judgment may be performed once. 4C, for example, the area of the area a1 and the area of the area a2 can be obtained respectively, and then the sum of the area of the area a1 and the area of the area a2 can be calculated, and it is judged whether the sum is greater than the electricity threshold value. Alternatively, the area of the area a1 and the area of the area a2 are obtained respectively, and then the area of the area a1 and the area of the area a2 are respectively compared with the corresponding threshold values. The threshold value corresponding to the area of the area a1 is, for example, the aforementioned electric power threshold value, and the threshold value corresponding to the area of the area a2 is, for example, 0 or a very small value. From another perspective, it is equivalent to count the power consumed by charging with constant current in the preset time interval Tdef3' and the power consumed by charging with constant current in the preset time interval Tdef3", and then obtain the total power for judgment.

Corresponding to the embodiment shown in FIG. 4C , in one embodiment, the method for testing a semi-finished battery cell provided by the present invention may further include the following steps. Please refer to FIG. 5 , which illustrates another embodiment of the present invention. The method flow chart of the partial steps of the battery cell semi-finished product testing method. In step S201, a plurality of current charging times charged at a constant current in a preset time interval are counted. In step S203, a plurality of current charging quantities are obtained according to the constant current and the current charging time. In step S205, it is judged whether each current charging power is greater than the corresponding power threshold, and when one of the current charging power is greater than the corresponding power threshold, it is judged that the insulation degree of the semi-finished battery cell is poor.

As mentioned above, in the battery cell semi-finished product testing method provided by the present invention, it is determined whether the total power is greater than the power threshold value QREF, so as to judge the insulation degree of the battery cell semi-finished product. In one embodiment, the power threshold value QREF is, for example, a theoretical ideal charge amount plus a tolerance value, and the ideal charge amount may be obtained from theory, manufacturing process parameters, or experience, or, for example, It is the total amount of electricity required to charge the semi-finished battery cell 10 to the voltage threshold VTH at the constant current. The size of the tolerance value can be defined by those skilled in the art according to actual needs, and is not limited here.

In another embodiment, the power threshold value QREF is obtained by charging the semi-finished battery cell for many times, and adding a tolerance value to the total experimental charge of one charging at a constant current. Please refer to FIG. 6 to illustrate this. FIG. 6 is a schematic diagram of a voltage difference when charging a semi-finished battery cell according to another embodiment of the present invention. FIG. 6 shows the reference time interval Tref and the actual test interval Ttest. The relevant details of the actual test interval Ttest are as described above, and will not be repeated here. A charging step similar to the actual test interval Ttest is performed in the reference time interval Tref. More specifically, the reference time interval Tref defines a constant current charging interval CCref and a constant voltage charging interval CVref. In the reference time interval Tref, the semi-finished battery cell to be tested is charged with a constant current before the constant current charging interval CCref. , until the voltage difference of the semi-finished battery cell to be tested is not less than the aforementioned voltage threshold VTH. In the constant voltage charging interval CCref, the semi-finished battery cell to be tested is charged at a constant voltage. The total power consumed by charging with a constant current in the reference time interval Tref is used as a reference total power. This reference total power plus the tolerance value is the aforementioned power threshold value QREF

Corresponding to the embodiment shown in FIG. 6 , in an embodiment, the method for testing a semi-finished battery cell provided by the present invention may further include the following steps to generate a power threshold value QREF. Please refer to FIG. 7 . FIG. 7 is a method flow chart illustrating some steps of a method for testing a semi-finished battery cell according to another embodiment of the present invention. In step S301, in the reference time interval, when the voltage difference between the first conducting portion and the second conducting portion is smaller than the voltage threshold, the semi-finished battery cell is charged with a constant current, and the reference time interval is earlier than the preset time interval . In step S303, in the reference time interval, when the voltage difference between the first conducting portion and the second conducting portion is greater than or equal to the voltage threshold, the semi-finished battery cell is charged with a constant voltage. In step S305 , the reference total power for charging the semi-finished battery cell with a constant current in the reference time interval is obtained, and the power threshold value is the reference total power plus the tolerance value.

In view of the above, the present invention proposes a method for testing semi-finished battery cells, by judging whether the total charge amount of the semi-finished battery cells charged with a constant current is greater than the power threshold value, so as to determine whether the insulation degree of the semi-finished battery cells meets the requirements. In this way, not only the test time is saved, but for a stand-alone product, the test can be performed several times in a row to compare the test conditions under different tests. In addition, compared with the qualitative analysis method that can only detect whether there is a short circuit in the past, the judgment based on the total charge amount provides a quantitative analysis method, which is quite practical.

The detailed features and advantages of the present invention are described in detail below in the embodiments, and the content is sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the protection scope of the claims and the appendix Figures, any person skilled in the art can easily understand the related objects and advantages of the present invention. The following examples further illustrate the concept of the present invention in further detail, but are not intended to limit the scope of the present invention in any way.

Claims (7)

1. A battery cell semi-finished product testing method, it is characterized in that, this battery core semi-finished product testing method is applicable to a battery core semi-finished product, this battery core semi-finished product comprises a first electrode and a second electrode, this first electrode and this second The electrodes are alternately stacked, an insulating layer is arranged between the first electrode and the second electrode, the first electrode is connected to a first conductive portion, and the second electrode is connected to a second conductive portion, and the test method includes: When the voltage difference between the first conducting portion and the second conducting portion is less than a voltage threshold, charging the semi-finished battery cell with a certain current; When the voltage difference between the first conducting portion and the second conducting portion is greater than or equal to the voltage threshold, charging the semi-finished battery cell with a certain voltage; obtaining a total amount of electricity charged to the semi-finished battery cell with the constant current during the predetermined time interval after starting charging; and Judging whether the total power is greater than a power threshold, when the total power is greater than the power threshold, it is judged that the insulation degree of the semi-finished battery cell is poor, The battery cell semi-finished product test method further includes: In a reference time interval, when the voltage difference between the first conductive portion and the second conductive portion is less than the voltage threshold, the battery cell semi-finished product is charged with a certain current, and the reference time interval is earlier than the preset time interval; In the reference time interval, when the voltage difference between the first conducting portion and the second conducting portion is greater than or equal to the voltage threshold, charging the semi-finished battery cell with a certain voltage; and A reference total power for charging the semi-finished battery cell with the constant current in the reference time interval is obtained, and the power threshold value is the reference total power plus a tolerance value. 2 . The method for testing a semi-finished battery cell as claimed in claim 1 , wherein the predetermined time interval covers a part of the time interval during which the semi-finished battery cell is charged at the constant voltage. 3 . 3 . The method for testing a semi-finished battery cell as claimed in claim 2 , wherein a total time of charging with the constant current in the preset time interval is counted, and the total amount of electricity is obtained according to the constant current and the total time. 4 . 4 . The method for testing the semi-finished battery cell as claimed in claim 1 , wherein after charging the semi-finished battery cell with the constant voltage, the total amount of electricity charged to the semi-finished battery cell with the constant current is counted. 5 . 5 . The method for testing a semi-finished battery cell according to claim 4 , wherein a total time for charging the semi-finished battery cell with the constant current before charging the semi-finished battery cell with the constant voltage is counted, and based on the constant current and the total time, 5 . Integrate to get the total power. 6 . The method for testing a semi-finished battery cell as claimed in claim 1 , wherein the power threshold value is an ideal charge amount corresponding to the semi-finished battery cell plus a tolerance value. 7 . 7. A battery cell semi-finished product testing method, characterized in that the battery core semi-finished product testing method is applicable to a battery core semi-finished product, the battery core semi-finished product comprising a first electrode and a second electrode, the first electrode and the second The electrodes are alternately stacked, an insulating layer is arranged between the first electrode and the second electrode, the first electrode is connected to a first conductive portion, and the second electrode is connected to a second conductive portion, and the test method includes: When the voltage difference between the first conducting portion and the second conducting portion is less than a voltage threshold, charging the semi-finished battery cell with a certain current; When the voltage difference between the first conducting portion and the second conducting portion is greater than or equal to the voltage threshold, charging the semi-finished battery cell with a certain voltage; obtaining a total amount of electricity charged to the semi-finished battery cell with the constant current during the predetermined time interval after starting charging; and Judging whether the total power is greater than a power threshold, when the total power is greater than the power threshold, it is judged that the insulation degree of the semi-finished battery cell is poor, Wherein, the preset time interval covers part of the time interval in which the semi-finished battery cell is charged with the constant voltage, The battery cell semi-finished product test method further includes: Counting a plurality of current charging times charged at the constant current in the preset time interval; obtaining a plurality of current charging amounts according to the constant current and the current charging times; and It is judged whether each of the current charging power is greater than the corresponding power threshold, and when one of the current charging power is greater than the corresponding power threshold, it is judged that the insulation degree of the semi-finished battery cell is poor.

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