Battery cell detection method, packaging structure, battery cell, battery and electric equipment

Abstract

The invention provides a battery cell detection method, a packaging structure, a battery cell, a battery and electric equipment, and relates to the technical field of batteries. The battery cell detection method is applied to a battery cell, and comprises the following steps: arranging an electroluminescent film on a packaging film of the battery cell, and electrically connecting the electroluminescent film with a first tab led out from the battery cell through a conductive piece; and detecting whether the electroluminescent film emits light or not so as to determine the electrical connection state of the second tab led out from the battery cell and the packaging film, thereby determining whether the battery cell is short-circuited or not. According to the battery cell detection method, the problem that defective products flow out due to the fact that whether the battery cell is short-circuited or not cannot be accurately recognized when the battery cell is offline can be solved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell detection method, a packaging structure, a battery cell, a battery, and an electrical device. Background Art

[0002] The tabs are metal conductors that lead the positive and negative electrodes from the battery cell and are the contact points when the battery cell is charging and discharging. When the tabs touch the shell, that is, when the tabs, which are metal conductors, are electrically connected to the battery cell shell, it will cause the battery cell to short-circuit, generate a large amount of current inside the battery cell, cause the battery cell to heat up, and even pose a risk of explosion.

[0003] Therefore, it is necessary to detect whether there is a short circuit in the battery cell. For example, it is detected by edge resistance test. In the related art, a wire is usually used to connect one of the tabs to the aluminum-plastic film, and a voltage is applied through an external power supply to test the resistance of the battery cell. However, when the tab contact area is small, the impact on the resistance of the battery cell is small, which may lead to failure to identify it and the risk of outflow. Summary of the invention

[0004] The present application provides a battery cell detection method, a packaging structure, a battery cell, a battery and an electrical device, which can solve the problem that it is impossible to accurately identify whether a battery cell is short-circuited when the battery cell is off the production line, resulting in the outflow of defective products.

[0005] In a first aspect, the present application provides a battery cell detection method, which is applied to a battery cell, and the method comprises:

[0006] Arranging an electroluminescent film on the packaging film of the battery cell, and electrically connecting the electroluminescent film to a first electrode tab led out from the battery cell through a conductive member;

[0007] Whether the electroluminescent film emits light is detected to determine the electrical connection state between the second electrode tab led out from the battery cell and the packaging film, thereby determining whether the battery cell is short-circuited.

[0008] In the battery cell detection method provided by the present application, an electroluminescent film may be provided on the packaging film of the battery cell. The electroluminescent film is electrically connected to the packaging film. The packaging film is electrically connected to the first pole ear through a conductive member. Therefore, when the second pole ear touches the shell, that is, when the second pole ear is electrically connected to the packaging film, a connected circuit can be formed between the electroluminescent film, the packaging film, the first pole ear, the second pole ear and the battery cell. It is easy to understand that at this time, the battery cell is in a short-circuit state. The battery cell can provide voltage to the electroluminescent film. Therefore, the staff or user can determine whether the battery cell has a short-circuit phenomenon based on whether the electroluminescent film emits light.

[0009] Therefore, as long as the second pole ear touches the shell, the closed loop formed can be used to provide a luminous electric field for the electroluminescent film to make the electroluminescent film emit light, regardless of the size of the contact area between the second pole ear and the packaging film. In other words, when the contact area between the second pole ear and the packaging film is small, accurate identification of the short circuit condition of the battery cell can also be achieved. The staff or user can accurately judge whether the second pole ear touches the shell based on whether the electroluminescent film is luminous, thereby determining whether the battery cell is short-circuited, which is conducive to reducing the possibility of short-circuited battery cell outflow.

[0010] According to an embodiment of the present application, the detecting whether the electroluminescent film emits light to determine the electrical connection state between the second electrode tab led out from the battery cell and the packaging film, thereby determining that the battery cell is short-circuited includes:

[0011] If it is detected that the electroluminescent film emits light, it is determined that the second electrode tab is in an electrically connected state with the packaging film, and the battery cell is determined to be short-circuited;

[0012] If it is detected that the electroluminescent film does not emit light, it is determined that the second electrode tab is in a non-electrically connected state with the packaging film.

[0013] According to an embodiment of the present application, after detecting whether the electroluminescent film emits light to determine the electrical connection state between the second electrode tab led out from the battery cell and the packaging film, the method further includes:

[0014] If it is determined that the battery cell is short-circuited, detecting the luminous intensity of the electroluminescent film;

[0015] The contact area between the second electrode tab and the packaging film is determined according to the luminous intensity of the electroluminescent film, and the luminous intensity is proportional to the contact area.

[0016] According to one embodiment of the present application, there are multiple electroluminescent films, and the multiple electroluminescent films have the same voltage threshold and different current thresholds;

[0017] The step of determining the contact area between the second electrode tab and the packaging film according to the luminous intensity of the electroluminescent film comprises:

[0018] The size of the contact area between the second electrode tab and the packaging film is determined according to the one with the largest luminous intensity among the multiple electroluminescent films.

[0019] In a second aspect, the present application provides a packaging structure for packaging a positive electrode sheet, a separator and a negative electrode sheet, wherein one of the positive electrode sheet and the negative electrode sheet can lead to a first electrode tab, and the other of the positive electrode sheet and the negative electrode sheet can lead to a second electrode tab. The packaging structure includes:

[0020] A packaging film, wherein the packaging film is electrically connected to the first electrode tab via a conductive member;

[0021] An electroluminescent film, wherein the electroluminescent film is disposed on the packaging film, and the electroluminescent film is used to confirm the electrical connection state between the second electrode tab and the packaging film according to its own luminescent state.

[0022] According to an embodiment of the present application, the packaging film includes a barrier layer, the barrier layer is electrically connected to the first electrode tab through the conductive member, and the electroluminescent film is disposed on an outer surface of the barrier layer.

[0023] According to an embodiment of the present application, the packaging film further includes an adhesive layer, and the electroluminescent film is fixed on the barrier layer through the adhesive layer.

[0024] According to one embodiment of the present application, the electroluminescent film includes silicate, oxide, rare earth organic matter, inorganic powder and conductive oil film.

[0025] According to an embodiment of the present application, there are multiple electroluminescent films; the voltage thresholds of the multiple electroluminescent films are the same, and the current thresholds of the multiple electroluminescent films are different.

[0026] According to an embodiment of the present application, a plurality of the electroluminescent films are arranged at intervals along the long side direction of the packaging structure.

[0027] In a third aspect, the present application provides a battery cell, the battery cell comprising:

[0028] First pole lug;

[0029] a second pole lug, wherein the second pole lug has a polarity opposite to that of the first pole lug;

[0030] In the packaging structure described in any of the above embodiments, part of the first electrode tab and part of the second electrode tab are exposed outside the packaging structure;

[0031] A conductive member, one end of which is electrically connected to the first electrode tab, and the other end of which is electrically connected to the packaging film.

[0032] In a fourth aspect, the present application provides a battery, comprising the battery cell in any of the above embodiments.

[0033] In a fifth aspect, the present application provides an electrical device comprising at least one battery cell or battery.

[0034] In addition to the technical problems solved by the embodiments of the present invention described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of the technical solutions, other technical problems that can be solved by the battery cell detection method, packaging structure, battery cell, battery and electrical equipment provided by the embodiments of the present invention, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0036] Figure 1 This is a flow chart of a battery cell detection method according to an embodiment of the present application;

[0037] Figure 2 A flow chart of a battery cell detection method according to another embodiment of the present application;

[0038] Figure 3 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0039] Figure 4 It is a schematic structural diagram of a battery cell according to another embodiment of the present application.

[0040] Description of reference numerals:

[0041] 100-battery cell;

[0042] 110- packaging structure; 111- packaging film; 112- electroluminescent film;

[0043] 120-first pole lug;

[0044] 130- second pole lug;

[0045] 140-conductive parts;

[0046] 10- External power supply.

[0047] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0049] The battery cell provided in the embodiment of the present application may be a lithium ion battery cell, for example, a lithium ion secondary battery cell, a lithium sulfur battery cell, or a sodium lithium ion battery cell, etc., which is not limited in the present application.

[0050] The battery cell provided in the embodiment of the present application can be applied to electrical equipment. The electrical equipment can be conventional electrical equipment in the art, for example, power equipment (such as electric vehicles, electric cars), electronic equipment (such as mobile phones, tablet computers, laptops, digital cameras, etc.), wearable equipment (such as watches, bracelets, VR glasses, etc.), without limitation.

[0051] For electronic devices and wearable devices with small size, the number of battery cells can be one. When the power-consuming device is a vehicle device such as an electric vehicle, the number of battery cells can be multiple to form a battery module. The battery module can be used as a driving power source for the vehicle, replacing or partially replacing fuel, so that it can be used to provide driving power for the vehicle. For example, the battery module can provide electrical energy for the drive motor. The drive motor is connected to the wheels on the vehicle through a transmission mechanism to drive the vehicle.

[0052] The battery cell includes two electrodes with opposite polarities and a separator. The electrodes with opposite polarities are respectively a positive electrode and a negative electrode. The separator is located between the positive electrode and the negative electrode to insulate and isolate the positive electrode and the negative electrode. The positive electrode, the separator and the negative electrode can be formed into a wound battery cell by a winding process. Alternatively, the positive electrode, the separator and the negative electrode can also be stacked in a certain stacking order to form a laminated battery cell, which is not limited in the embodiments of the present application.

[0053] The battery cell includes two tabs with opposite polarities, namely the positive tab and the negative tab. The positive tab can be led out from the positive electrode sheet, and the negative tab can be led out from the negative electrode sheet. The positive tab and the negative tab can be used to connect to an external circuit.

[0054] During the charging process of lithium-ion batteries, lithium atoms in the positive electrode lose electrons and are converted into lithium ions. Lithium ions can migrate to the negative electrode through the electrolyte under the action of the electric field. Lithium ions are captured by the micropores of the graphite layered structure in the negative electrode and combine with electrons flowing in from the external circuit to form lithium intercalation compounds. In this process, the electrical energy provided by the external power source can be converted into chemical energy to be stored in the battery cell.

[0055] In some examples, the battery cell of the embodiment of the present application may be a soft-pack battery cell. The outside of the soft-pack battery cell is provided with a packaging film such as an aluminum-plastic film. Part of the positive electrode ear and part of the negative electrode ear may be led out of the battery cell. The positive electrode ear and the negative electrode ear are insulated from the packaging film by an electrode ear glue.

[0056] The tabs are metal conductors that lead the positive and negative electrodes from the battery cell and are the contact points of the battery cell during charging and discharging. When the tabs (positive or negative) are electrically connected to the packaging film, that is, when the tabs touch the shell, the positive and negative electrodes will be electrically connected, the battery cell will be short-circuited, and a large amount of current will be generated inside the battery cell, causing the battery cell to heat up and even have the risk of explosion.

[0057] Therefore, when the battery cell is about to be offline, it is necessary to detect whether the battery cell has a short circuit. For example, it is detected by edge resistance testing. In the related art, a wire is usually used to connect one of the tabs to the aluminum-plastic film, and a voltage is applied through an external power supply to test the resistance of the battery cell. However, when the tab contact shell area is small, the impact on the resistance of the battery cell is small, which can easily lead to failure to identify it, and there is a risk of outflow.

[0058] Based on the above technical problems, the applicant has improved the existing battery cell detection method. In an embodiment of the present application, an electroluminescent film may be provided on the packaging film of the battery cell. The electroluminescent film is electrically connected to the packaging film. The packaging film is electrically connected to the first pole ear through a conductive member. Therefore, when the second pole ear touches the shell, that is, when the second pole ear is electrically connected to the packaging film, a connected circuit can be formed between the electroluminescent film, the packaging film, the first pole ear, the second pole ear and the battery cell. It is easy to understand that at this time, the battery cell is in a short-circuit state. The battery cell can provide voltage to the electroluminescent film. Therefore, the staff or user can determine whether the battery cell has a short-circuit phenomenon based on whether the electroluminescent film emits light.

[0059] The battery cell detection method, packaging structure, battery cell, battery and electrical equipment provided by the present application are described below with reference to the accompanying drawings and in combination with specific embodiments.

[0060] See also Figures 1 to 4As shown, the battery cell detection method is applied to the battery cell. The battery cell 100 may include a packaging structure 110, a first pole ear 120 and a second pole ear 130. The packaging structure 110 may include a packaging film 111 and an electroluminescent film 112. The packaging film 111 is used to package the battery cell 100. The electroluminescent film 112 is disposed on the packaging film 111 and is electrically connected to the packaging film 111. The electroluminescent film 112 is electrically connected to the first pole ear 120 through a conductive member 140. The conductive member 140 may be a wire or other metal conductive material.

[0061] See also Figure 1 As shown, the battery cell detection method of the embodiment of the present application includes:

[0062] S100 , disposing an electroluminescent film 112 on the packaging film 111 of the battery cell 100 , and electrically connecting the electroluminescent film 112 and the first electrode tab 120 led out of the battery cell 100 through the conductive member 140 .

[0063] S200 , detecting whether the electroluminescent film 112 emits light, so as to determine the electrical connection state between the second electrode tab 130 led out from the battery cell 100 and the packaging film 111 , thereby determining whether the battery cell 100 is short-circuited.

[0064] The electroluminescent film 112 is a material that can emit light under the action of an electric field. When a power source is configured to provide an electric field for the electroluminescent film 112, the electroluminescent film 112 can generate a luminescent phenomenon, that is, under the stimulation of the electric field, the electrons and holes inside the electroluminescent film 112 material release energy when they recombine, and thus can be emitted in the form of light.

[0065] In the embodiment of the present application, the power source for providing an electric field for the electroluminescent film 112 may be a battery cell 100 or an external power source 10. Figure 3 As shown, one end of the external power source 10 can be electrically connected to the first pole ear 120 through a conductive member 140 , and the other end of the external power source 10 can be electrically connected to the second pole ear 130 through another conductive member 140 to provide an electric field for the electroluminescent film 112 .

[0066] The present application is described by taking the battery cell 100 providing an electric field for the electroluminescent film 112 as an example.

[0067] In some examples, the electroluminescent film 112 may include semiconductor materials such as silicates, oxides, rare earth organics, inorganic powders, and conductive oil films.

[0068] In some examples, the electroluminescent film 112 may include electroluminescent powder and a conductive oil film.

[0069] In some examples, when the electroluminescent film 112 is in a light-emitting state, the color of the light can be set according to the material of the electroluminescent film 112. In the embodiment of the present application, the light-emitting color of the electroluminescent film 112 is not limited. For example, the color of the electroluminescent film 112 can be red, blue, green, etc.

[0070] It should be noted that one of the first pole ear 120 and the second pole ear 130 is a positive pole ear, and the other is a negative pole ear, which is not limited in the embodiments of the present application. When the first pole ear 120 is used as a positive pole ear to be electrically connected to the electroluminescent film 112 through the conductive member 140, whether the electroluminescent film 112 emits light can be used to detect the shell contact phenomenon of the negative pole ear (second pole ear 130), that is, the electrical connection state of the negative pole ear (second pole ear 130) and the packaging film 111. Similarly, when the first pole ear 120 is used as a negative pole ear to be electrically connected to the electroluminescent film 112 through the conductive member 140, whether the electroluminescent film 112 emits light can be used to detect the shell contact phenomenon of the positive pole ear (second pole ear 130), that is, the electrical connection state of the positive pole ear (second pole ear 130) and the packaging film 111.

[0071] In some examples, the light emitted by the electroluminescent film 112 can be used to determine that the second electrode tab 130 is electrically connected to the packaging film 111 .

[0072] Specifically, since the electroluminescent film 112 is electrically connected to the first pole ear 120 and the packaging film 111, when the second pole ear 130 is also electrically connected to the packaging film 111, a closed circuit is formed between the electroluminescent film 112, the first pole ear 120, the packaging film 111, the second pole ear 130 and the battery cell 100. At this time, the battery cell 100 can provide an electric field for the electroluminescent film 112, so that the electroluminescent film 112 emits light. It is easy to understand that since a closed circuit is formed between the electroluminescent film 112, the first pole ear 120, the packaging film 111, the second pole ear 130 and the battery cell 100, the first pole ear 120 and the second pole ear 130 with opposite polarities are electrically connected, and the battery cell 100 is short-circuited.

[0073] Correspondingly, when there is no electrical connection between the second pole ear 130 and the packaging film 111, the first pole ear 120 and the second pole ear 130 are not connected, the battery cell 100 cannot provide an electric field for the packaging film 111, and the electroluminescent film 112 does not emit light. At this time, there is no electrical conduction between the first pole ear 120 and the second pole ear 130, and the battery cell 100 does not short-circuit.

[0074] It is easy to understand that since the second pole ear 130 is electrically connected to the packaging film 111, the battery cell 100 can provide the required electric field for the electroluminescent film 112 to emit light. Therefore, as long as the second pole ear 130 touches the shell, the closed loop formed can be used to provide the electroluminescent film 112 with a luminous electric field to make the electroluminescent film 112 emit light, regardless of the size of the contact area between the second pole ear 130 and the packaging film 111. In other words, when the contact area between the second pole ear 130 and the packaging film 111 is small, accurate identification of the short circuit condition of the battery cell 100 can also be achieved. The staff or user can accurately judge whether the second pole ear 130 touches the shell according to whether the electroluminescent film 112 emits light, so as to determine whether the battery cell 100 is short-circuited, which is conducive to reducing the possibility of the short-circuited battery cell 100 flowing out.

[0075] In some examples, S200 may specifically include:

[0076] If it is detected that the electroluminescent film 112 emits light, it is determined that the second electrode tab 130 is in an electrically connected state with the packaging film 111, and it is determined that the battery cell 100 is short-circuited;

[0077] If it is detected that the electroluminescent film 112 does not emit light, it is determined that the second electrode tab 130 and the packaging film 111 are in a non-electrically connected state.

[0078] When the battery cell 100 is short-circuited, the battery cell 100 can be used to provide the electroluminescent film 112 with the electric field required for luminescence, and the electroluminescent film 112 emits light. When the battery cell 100 is not short-circuited, the battery cell 100 cannot provide the electroluminescent film 112 with the electric field required for luminescence, and the electroluminescent film 112 does not emit light. Therefore, the method for the user or staff to determine whether the battery cell 100 is short-circuited based on whether the electroluminescent film 112 emits light is intuitive, convenient and accurate.

[0079] In some examples, during the use of the battery cell 100, whether the electroluminescent film 112 emits light can be continuously monitored. When the electroluminescent film 112 emits light, a warning can be issued to prompt the user to handle it in time to avoid safety hazards.

[0080] In particular, when applied to a vehicle, the battery module includes a plurality of battery cells 100. When a battery module fails, the luminescence of the electroluminescent film 112 on each battery cell 100 can be determined to check whether a short circuit occurs in the plurality of battery cells 100, so that the faulty battery cell 100 can be quickly and accurately identified, and the battery cell 100 can be maintained or replaced, which is conducive to improving maintenance efficiency and reducing safety hazards.

[0081] In some examples, when detecting whether the electroluminescent film 112 is emitting light on the production line, the staff may observe the luminescence status of the electroluminescent film 112 with the naked eye, or may detect the luminescence status of the electroluminescent film 112 through a light sensor, which is not specifically limited in the present application.

[0082] Exemplarily, the light sensor may be a photosensitive probe. Each battery cell 100 may correspond to a photosensitive probe. The photosensitive probe may monitor the light emitting state of the electroluminescent film 112. When the electroluminescent film 112 emits light, the photosensitive probe may identify the light and send a signal indication to the battery management system. The user may identify the battery cell 100 that has a short circuit according to the signal indication.

[0083] Therefore, by setting a light sensor at the battery cell 100 to monitor the electroluminescent film 112, online tracking detection of the short circuit condition of the battery cell 100 can be achieved, so as to achieve in-situ monitoring of the short circuit condition of the battery cell 100. The battery cell 100 can be directly detected in the application scenario to obtain the current state of the battery cell 100 in real time, so as to accurately reflect the real situation of the battery cell 100 in the current state. In addition, the battery cell 100 does not need to be disassembled during the detection process, and the detection process is simple and convenient.

[0084] In some examples, the applicant tested 1,000 off-line battery cells 100 using the above method and found that 6 batteries had the second pole ear 130 touching the shell, which effectively avoided the risk of defective products flowing out, helped reduce safety hazards, and improved user experience.

[0085] See also Figure 2 As shown, after S200, the following may also be included:

[0086] S400 , if it is determined that the battery cell 100 is short-circuited, the luminous intensity of the electroluminescent film 112 is detected.

[0087] S500: Determine the contact area between the second electrode tab 130 and the packaging film 111 according to the luminous intensity of the electroluminescent film 112. The luminous intensity may be proportional to the contact area.

[0088] According to Ohm's law, V=I*R, where V represents voltage, I represents current, and R represents resistance. When the voltage is constant, the greater the current, the smaller the resistance. Therefore, when the luminous intensity of the electroluminescent film 112 is strong, the greater the current I passing through the electroluminescent film 112, the smaller the resistance R. The luminous intensity of the electroluminescent film 112 is inversely proportional to the resistance R.

[0089] According to the basic formula of resistance R: R = ρ*(L / S), R represents resistance, ρ represents the resistivity of the material (an inherent material property, which is a constant value), L represents the length of the current passing through the material, and S represents the cross-sectional area of ​​the current passing through the material. When other conditions are constant, when the contact area between the second pole tab 130 and the packaging film 111 is large, the larger the cross-sectional area S of the current passing through the electroluminescent film 112, the smaller the resistance R. Therefore, the resistance R is inversely proportional to the contact area between the second pole tab 130 and the packaging film 111.

[0090] Since the luminous intensity of the electroluminescent film 112 is inversely proportional to the resistance R, and the resistance R is inversely proportional to the contact area between the second pole ear 130 and the packaging film 111, when other conditions remain constant, the luminous intensity of the electroluminescent film 112 is directly proportional to the contact area between the second pole ear 130 and the packaging film 111.

[0091] It is easy to understand that when the luminous intensity of the electroluminescent film 112 is large, the current passing through the electroluminescent film 112 is large and the resistance value is small, so there is a relatively large contact area between the second electrode 130 and the packaging film 111. The staff needs to maintain the short-circuited battery cell 100 in time.

[0092] In the embodiment of the present application, when the battery cell 100 is short-circuited, the electroluminescent film 112 emits light. At this time, it can be judged whether the second pole ear 130 and the packaging film 111 have a large contact area according to the light-emitting state of the electroluminescent film 112, so as to help collect the probability of the second pole ear 130 contacting the shell during the manufacturing and use of the battery cell 100, and provide guidance for subsequent improvement.

[0093] In some examples, the light sensor can detect the luminous intensity of the electroluminescent film 112. Since the luminous intensity is proportional to the contact area, a luminous intensity threshold can be set. When the light sensor detects that the luminous intensity exceeds the threshold, it can be determined that there is a large contact area between the second electrode 130 and the packaging film 111, and a maintenance response needs to be issued immediately for the short-circuited battery cell 100.

[0094] In some examples, the electroluminescent film 112 may have a threshold voltage. When the battery cell 100 is short-circuited and the voltage across the electroluminescent film 112 reaches the threshold voltage of the electroluminescent film 112, the electroluminescent film 112 emits light.

[0095] For example, when the number of the electroluminescent film 112 is one, electroluminescent films 112 with different threshold voltages may be used.

[0096] Example 1

[0097] The electroluminescent film 112 is formed by mixing the red electroluminescent powder with the conductive ink and coated on the surface of the barrier layer (conductive layer) of the packaging film 111. The voltage is adjusted to reach the threshold voltage of the electroluminescent film 112 at 132V. The electroluminescent film 112 starts to emit light, and the light intensity is 0.5lux when tested by a light sensor (such as an illuminance meter). The voltage is adjusted to 200V and the light intensity is 27lux.

[0098] Example 2

[0099] The electroluminescent film 112 is formed by mixing red electroluminescent powder with conductive ink and coated on the surface of the barrier layer (conductive layer) of the packaging film 111. The voltage is adjusted to reach the threshold voltage of the electroluminescent film 112 at 184 V. The electroluminescent film 112 starts to emit light, and the light intensity is 0.5 lux when tested by a light sensor (such as an illuminance meter). The voltage is adjusted to 200 V and the light intensity is 4 lux.

[0100] Example 3

[0101] The electroluminescent film 112 is formed by mixing red electroluminescent powder with conductive ink and coated on the surface of the barrier layer (conductive layer) of the packaging film 111. The voltage is adjusted to reach the threshold voltage of the electroluminescent film 112 at 163 V. The electroluminescent film 112 starts to emit light, and the light intensity is 0.5 lux when tested by a light sensor (such as an illuminance meter). The voltage is adjusted to 200 V and the light intensity is 13 lux.

[0102] Comparative Example 1

[0103] The battery cell 100 whose surface of the barrier layer (conductive layer) of the packaging film 111 was not treated was used, and the voltage was adjusted to 200V and no light was emitted.

[0104]

[0105] Table 1 shows the light intensity at 200V of Examples 1, 2, 3 and Comparative Example 1. The specific test process is to test the light intensity of the electroluminescent film 112 by a light sensor (such as an illuminance meter). It can be seen that the more the voltage passing through the electroluminescent film 112 exceeds the threshold voltage of the electroluminescent film 112, the greater the light intensity of the electroluminescent film 112. Therefore, the staff can select electroluminescent films 112 with different threshold voltages according to different specifications of the battery cells 100.

[0106] In some achievable manners, there may be a plurality of electroluminescent films 112. In other words, a plurality of electroluminescent films 112 may be provided on the battery cell 100. The plurality of electroluminescent films 112 may have the same voltage threshold and different current thresholds.

[0107] Therefore, when it is determined that the battery cell 100 is short-circuited and the multiple electroluminescent films 112 are all in a luminous state, S600 can determine the size of the contact area between the second electrode tab 130 and the packaging film 111 according to the one with the highest luminous intensity among the multiple electroluminescent films 112 .

[0108] Since the multiple electroluminescent films 112 correspond to the same voltage threshold, when the battery cell 100 is short-circuited, the multiple electroluminescent films 112 can all be in a light-emitting state. Since the luminous intensity of the electroluminescent film 112 is proportional to the contact area, the greater the current flowing through the electroluminescent film 112, the stronger the light emitted by the electroluminescent film 112. By setting the multiple electroluminescent films 112 to have different current thresholds, the multiple electroluminescent films 112 can be used to present different luminous intensities, so that the contact area between the second pole ear 130 and the packaging film 111 can be judged according to the size of the luminous intensity.

[0109] Specifically, when multiple electroluminescent films 112 emit light, the corresponding resistance can be obtained according to the current threshold corresponding to the electroluminescent film 112 with the highest luminous intensity. Therefore, according to the current threshold and the size of the resistance, the contact area between the second electrode 130 and the packaging film 111 can be divided into different intervals for maintenance corresponding to different response schemes.

[0110] In some examples, in the process of detecting the short circuit condition of the battery cell 100, light sensors can be set at different node positions of the production line. The light sensors at different node positions can be used to detect the luminous state of the electroluminescent film 112 at different positions on the battery cell 100, so as to improve the detection efficiency.

[0111] It is easy to understand that when the light emitting states of multiple electroluminescent films 112 are detected by different light sensors, a blocking plate can be provided to prevent the light of other electroluminescent films 112 from affecting the light intensity of the electroluminescent film 112 currently being detected.

[0112] In some examples, the threshold voltage of the electroluminescent film 112 is related to the conductivity of the light-emitting layer. The clamping electric field strength decreases as the conductivity of the light-emitting layer increases. In addition, the material properties of the light-emitting layer of the electroluminescent film 112 can also effectively regulate the threshold voltage of the electroluminescent film 112. Therefore, the threshold voltage of the electroluminescent film 112 can be adjusted by adjusting one or more of the conductivity, preparation method and growth conditions of the light-emitting layer of the electroluminescent film 112.

[0113] For example, in the embodiment of the present application, the threshold voltage of the electroluminescent film 112 may be greater than or equal to 2 V. When the voltage of the battery cell 100 is greater than the threshold voltage, current flows through the barrier layer in the packaging film 111 to make the electroluminescent film 112 emit light.

[0114] See also Figure 4 As shown, the embodiment of the present application further provides a packaging structure 110, which can be used to package a positive electrode sheet, a separator and a negative electrode sheet. A first electrode tab 120 can be led out from one of the positive electrode sheet and the negative electrode sheet, and a second electrode tab 130 can be led out from the other of the positive electrode sheet and the negative electrode sheet.

[0115] The packaging structure 110 includes a packaging film 111 and an electroluminescent film 112. The packaging film 111 is electrically connected to the first electrode tab 120 via a conductive member 140. The electroluminescent film 112 is disposed on the packaging film 111. The electroluminescent film 112 is used to confirm the electrical connection state between the second electrode tab 130 and the packaging film 111 according to its own luminous state.

[0116] In the embodiment of the present application, the packaging film 111 can be used to package the positive electrode sheet, the diaphragm and the negative electrode sheet. The electroluminescent film 112 is electrically connected to the packaging film 111, and the packaging film 111 is electrically connected to the first pole ear 120 through the conductive member 140, so the first pole ear 120, the packaging film 111 and the electroluminescent film 112 can be electrically connected. When the second pole ear 130 is electrically connected to the packaging film 111, the first pole ear 120, the packaging film 111, the electroluminescent film 112 and the second pole ear 130 are electrically connected to cause a short circuit in the battery. In addition, since the first pole ear 120, the packaging film 111, the electroluminescent film 112 and the second pole ear 130 are electrically connected, the electric field required for luminescence can be provided to the electroluminescent film 112, so that the electroluminescent film 112 can emit light.

[0117] In summary, the luminous state of the electroluminescent film 112 can be used to effectively identify whether the second electrode tab 130 is electrically connected to the packaging film 111, thereby identifying whether a short circuit occurs in the battery cell 100. This detection method has high recognition efficiency and high accuracy.

[0118] In some achievable embodiments, the packaging film 111 may include a barrier layer. The barrier layer is electrically connected to the first electrode tab 120 via a conductive member 140. The electroluminescent film 112 may be disposed on the outer surface of the barrier layer.

[0119] In the embodiment of the present application, the barrier layer can have the function of blocking the transmission of water vapor and oxygen, and the barrier layer can have stamping forming performance to have better support.

[0120] In some examples, the packaging film 111 may be, but is not limited to, an aluminum-plastic film. The barrier layer of the packaging film 111 may be an aluminum foil layer. The barrier layer has electrical conductivity. Therefore, the electroluminescent film 112 may be disposed on the barrier layer to conduct current through the barrier layer.

[0121] It should be noted that the electroluminescent film 112 is disposed on the outer surface of the barrier layer, which means that the electroluminescent film 112 is located on the exposed surface of the battery cell 100 , so that the staff and users can easily confirm the luminous state of the electroluminescent film 112 .

[0122] In some achievable ways, the packaging film 111 of the embodiment of the present application may further include an adhesive layer. The electroluminescent film 112 is fixed on the barrier layer through the adhesive layer.

[0123] The packaging film 111 includes an outer resistance layer.

[0124] The outer resistance layer can be used to reduce the possibility of oxidation of the barrier layer, and can also reduce the possibility of scratching and damage to the outer surface of the battery cell 100. The outer resistance layer can be, but is not limited to, an insulating material such as nylon. The adhesive layer can be used to bond the barrier layer and the outer resistance layer.

[0125] During the preparation of the packaging structure 110, the electroluminescent film 112 may be first coated on the barrier layer, and then the barrier layer and the outer resistance layer may be bonded by the adhesive layer, so that the electroluminescent film 112 may be located between the barrier layer and the outer resistance layer. Alternatively, the powder of the electroluminescent film 112 may be mixed with the adhesive layer. When the barrier layer and the outer resistance layer are bonded by the adhesive layer, the electroluminescent film 112 may be fixed between the barrier layer and the outer resistance layer.

[0126] In some possible implementations, see Figure 4 As shown, there may be a plurality of electroluminescent films 112. The voltage thresholds of the plurality of electroluminescent films 112 are the same, and the current thresholds of the plurality of electroluminescent films 112 are different.

[0127] When the voltage thresholds of the multiple electroluminescent films 112 are the same, when a short circuit occurs in the battery cell 100, the multiple electroluminescent films 112 can all emit light. When the current thresholds of the multiple electroluminescent films 112 are different, the electroluminescent films 112 can present different light intensities when different currents pass through them. The greater the current passing through the electroluminescent film 112, the greater the light intensity of the electroluminescent film 112.

[0128] Since the larger the electrical connection contact area between the second pole tab 130 and the packaging film 111, the larger the current passing through the packaging film 111 and the electroluminescent film 112, the smaller the corresponding resistance value, and the stronger the light of the electroluminescent film 112. Therefore, it is possible to judge whether the electrical connection contact area between the second pole tab 130 and the packaging film 111 in the current short-circuited battery cell 100 is large by the luminous brightness of multiple electroluminescent films 112, so that maintenance response can be made in time.

[0129] In some examples, the embodiment of the present application does not limit the size and shape of the electroluminescent film 112. For example, Figure 4As shown, the electroluminescent film 112 may be rectangular and a plurality of electroluminescent films 112 may have intervals therebetween.

[0130] In some achievable embodiments, a plurality of electroluminescent films 112 may be arranged at intervals along the long side direction of the packaging structure.

[0131] In the embodiment of the present application, by arranging multiple electroluminescent films 112 at intervals, it is possible to conveniently block the luminous states of two adjacent electroluminescent films 112 through an opaque partition during the monitoring of the battery cell 100, so as to avoid the luminous states of the two adjacent electroluminescent films 112 interfering with each other, thereby affecting the accuracy of the light sensor detection.

[0132] The embodiment of the present application further provides a battery cell 100. The battery cell 100 may include a first electrode tab 120, a second electrode tab 130, and a packaging structure 110. The first electrode tab 120 and the second electrode tab 130 have opposite polarities.

[0133] Part of the first electrode tab 120 and part of the second electrode tab 130 may be exposed outside the packaging structure 110. One end of the conductive member 140 may be electrically connected to the first electrode tab 120, and the other end of the conductive member 140 may be electrically connected to the packaging film 111.

[0134] The battery cell 100 of the embodiment of the present application can have the function of detecting whether a short circuit occurs in itself. Therefore, during the application of the battery cell 100, the status of the battery cell 100 can be monitored in real time by the optical sensor, so that when a short circuit occurs in the battery cell 100, the user can be promptly notified, which is conducive to improving the safety performance of the battery cell 100 and reducing safety hazards.

[0135] The present application also provides a battery, which may include the battery cell 100 in any of the above embodiments.

[0136] The present application also provides an electric device. The electric device may include at least one battery cell 100 or battery in any of the above embodiments. The electric device may be a new energy vehicle, such as an electric vehicle or a hybrid vehicle, and may also be an energy storage device.

[0137] It should be noted here that the numerical values ​​and numerical ranges involved in this application are approximate values. Due to the influence of the manufacturing process, there may be a certain range of errors, which can be considered negligible by those skilled in the art.

[0138] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0139] In the description of the present application, it should be understood that the terms used, such as “center”, “length”, “width”, “thickness”, “top”, “bottom”, “up”, “down”, “left”, “right”, “front”, “back”, “vertical”, “horizontal”, “inside”, “outside”, “axial”, “circumferential”, etc., to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred position or component must have a specific direction, a specific structure and operation, and therefore should not be understood as a limitation on the present invention.

[0140] In the embodiments of the present application, the devices or elements referred to or implied must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise precisely and specifically specified.

[0141] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein.

[0142] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0143] The term "plurality" in this article refers to two or more than two. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship; in a formula, the character " / " indicates that the previous and next associated objects are in a "division" relationship.

[0144] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0145] It can be understood that in the embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A battery cell detection method, applied to a battery cell, characterized in that: The method comprises: Arranging an electroluminescent film on the packaging film of the battery cell, and electrically connecting the electroluminescent film to a first electrode tab led out from the battery cell through a conductive member; Whether the electroluminescent film emits light is detected to determine the electrical connection state between the second electrode tab led out from the battery cell and the packaging film, thereby determining whether the battery cell is short-circuited.

2. The method according to claim 1, characterized in that The detecting whether the electroluminescent film emits light to determine the electrical connection state between the second electrode tab led out from the battery cell and the packaging film, thereby determining whether the battery cell is short-circuited includes: If it is detected that the electroluminescent film emits light, it is determined that the second electrode tab is in an electrically connected state with the packaging film, and the battery cell is determined to be short-circuited; If it is detected that the electroluminescent film does not emit light, it is determined that the second electrode tab is in a non-electrically connected state with the packaging film.

3. The method according to claim 2, characterized in that After detecting whether the electroluminescent film emits light to determine the electrical connection state between the second electrode tab led out from the battery cell and the packaging film, the method further includes: If it is determined that the battery cell is short-circuited, detecting the luminous intensity of the electroluminescent film; The contact area between the second electrode tab and the packaging film is determined according to the luminous intensity of the electroluminescent film, and the luminous intensity is proportional to the contact area.

4. The method according to claim 3, characterized in that There are multiple electroluminescent films, and the multiple electroluminescent films have the same voltage threshold and different current thresholds; The step of determining the contact area between the second electrode tab and the packaging film according to the luminous intensity of the electroluminescent film comprises: The size of the contact area between the second electrode tab and the packaging film is determined according to the one with the largest luminous intensity among the multiple electroluminescent films.

5. A packaging structure (110) for packaging a positive electrode sheet, a separator and a negative electrode sheet, wherein one of the positive electrode sheet and the negative electrode sheet can be led out with a first electrode tab (120), and the other of the positive electrode sheet and the negative electrode sheet can be led out with a second electrode tab (130), characterized in that: include: A packaging film (111), wherein the packaging film (111) is electrically connected to the first electrode tab (120) via a conductive member (140); An electroluminescent film (112), wherein the electroluminescent film (112) is disposed on the packaging film (111), and the electroluminescent film (112) is used to confirm the electrical connection state between the second electrode tab (130) and the packaging film (111) based on its own luminescent state.

6. The packaging structure (110) according to claim 5, characterized in that: The packaging film (111) comprises a barrier layer, the barrier layer is electrically connected to the first electrode tab (120) via the conductive member (140), and the electroluminescent film (112) is arranged on the outer surface of the barrier layer.

7. The packaging structure (110) according to claim 6, characterized in that: The packaging film (111) further comprises an adhesive layer, and the electroluminescent film (112) is fixed on the barrier layer via the adhesive layer.

8. The packaging structure (110) according to claim 6, characterized in that: The electroluminescent film (112) comprises silicate, oxide, rare earth organic matter, inorganic powder and conductive oil film.

9. The packaging structure (110) according to claim 5, characterized in that: The number of the electroluminescent films (112) is multiple; the voltage thresholds of the multiple electroluminescent films (112) are the same, and the current thresholds of the multiple electroluminescent films (112) are different.

10. The packaging structure (110) according to claim 9, characterized in that: The plurality of electroluminescent films (112) are arranged at intervals along the long side direction of the packaging structure (110).

11. A battery cell, characterized in that: include: A first tab (120); A second pole lug (130), wherein the second pole lug (130) has a polarity opposite to that of the first pole lug (120); The packaging structure (110) according to any one of claims 5 to 10, wherein a portion of the first electrode tab (120) and a portion of the second electrode tab (130) are exposed outside the packaging structure (110); A conductive member (140), one end of the conductive member (140) being electrically connected to the first electrode tab (120), and the other end of the conductive member (140) being electrically connected to the packaging film (111) of the packaging structure.

12. A battery, characterized in that: include: The battery cell according to claim 11.

13. An electrical equipment, characterized in that: include: At least one battery cell as claimed in claim 11 or a battery as claimed in claim 12.

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