CN219457735U - Soft package battery core - Google Patents

Abstract

The utility model provides a soft-package battery cell, and belongs to the technical field of energy storage devices. The battery cell comprises a battery cell body and a tab, wherein the battery cell body extends to form a current collector, and the tab is connected with the current collector by ultrasonic welding; and a pressure-sensitive color-changing layer is arranged on one side of the current collector away from the tab and/or one side of the tab away from the current collector in the lamination direction of ultrasonic welding of the tab and the current collector. In the utility model, after the electrode lug and the current collector are ultrasonically welded, the pressure-sensitive color-changing layer can reflect the pressure condition of the current collector and the electrode lug through color change. Through the recognition to the pressurized condition, can judge the ultrasonic welding condition, it is simple and convenient, little to the production process influence, reduce product later stage reworking and defective rate, improve product production efficiency. Meanwhile, the soft-package battery core of local cold joint or whole cold joint can be screened out through the color comparison of the pressure-sensitive color-changing layers, so that the safety performance of a soft-package battery core product can be improved, and the subsequent potential safety hazard is reduced.

Description

Soft package battery core

Technical Field

The utility model belongs to the technical field of energy storage devices, and particularly relates to a soft-package battery cell.

Background

Soft pack cells are a common form of cell for existing secondary batteries. The soft-package battery cell generally comprises a battery cell body formed by stacking a plurality of layers of pole pieces, and extension parts of the pole pieces are sequentially stacked and welded to form current collectors respectively connected with the pole pieces. With the increasing capacity demand of the power battery, the number of pole pieces in the existing soft-package battery core is gradually increased, so that the total thickness of the current collector is thicker and thicker. Meanwhile, the current collector is also commonly welded with a tab for connecting with the current collector to collect current. At present, ultrasonic welding is generally adopted for welding among layers of the current collector and between the current collector and the tab. During ultrasonic welding, the current collector and the tab need to be pressed in the stacking direction of the current collector, namely the stacking direction of the current collector and the tab, so as to finish welding. In the ultrasonic welding process, as the thickness of the current collector increases, poor lamination, uneven surface and other conditions are more likely to occur between layers in the current collector and between the current collector and the tab, so that the phenomena of cold joint, cold joint and the like are likely to occur between the layers in the current collector and between the current collector and the tab due to uneven pressure. However, at present, if the current collector is welded and then subjected to uneven pressure, the phenomenon of cold joint and the like occurs, the current collector can be judged only through a subsequent tensile test or voltage test. The tensile test is destructive, can only be sampled and carried out, can not detect every electric core, and has the risk of missing to examine. The voltage test can only detect the situation that the integral cold joint is serious, the situation that the cold joint is light can only appear after a plurality of cyclic tests, and the voltage test can not detect the situation of the local cold joint. Meanwhile, the existing test mode is complex in steps and located at the rear end of a production link, and the false soldering phenomenon cannot be found timely, so that the overall production efficiency of the battery cell is affected.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present utility model is to provide a soft package battery cell for solving the problem that the cold joint problem caused by uneven pressure is difficult to find in the prior art.

In order to achieve the above and other related objects, the present utility model provides a soft package battery core, including a battery core body and a tab, wherein the battery core body extends to form a current collector, and the tab is connected with the current collector by ultrasonic welding; and in the lamination direction of ultrasonic welding of the electrode lug and the current collector, a pressure-sensitive color-changing layer is arranged on one side of the current collector away from the electrode lug and/or one side of the electrode lug away from the current collector.

Optionally, a protective sheet for protecting the current collector during ultrasonic welding is arranged on a side of the current collector away from the tab, and when the pressure sensitive color-changing layer is arranged on a side of the current collector away from the tab, the pressure sensitive color-changing layer is arranged on a side of the protective sheet away from the current collector.

Optionally, the pressure-sensitive color-changing layer is a pressure-sensitive color-changing coating layer arranged in a coating way.

Optionally, the thickness of the pressure sensitive color-changing coating is 0.01 mm-0.05 mm.

Optionally, the pressure-sensitive color-changing layer comprises a base layer, a plurality of containing holes are formed in the base layer, and the containing holes are filled with pressure-sensitive color-changing materials.

Optionally, the porosity of the accommodating hole is 10% -60%.

Optionally, the thickness of the base layer is 0.1 mm-0.2 mm.

Optionally, the material of the pressure-sensitive color-changing layer is an alkene compound, an amide polymer or a metal halogenated organic compound.

Optionally, the pressure-sensitive color-changing layer includes two or more color-changing regions, and at least one color-changing region is made of a material different from that of the other color-changing regions.

Optionally, the battery cell further comprises a shell, the battery cell body is accommodated in the shell, the current collector is connected to one end of the tab, and the other end of the tab penetrates through the shell.

Optionally, a sealant is disposed on the tab, and the tab and the housing are sealed by the sealant.

As described above, the soft-package battery cell has the following beneficial effects: because the pressure-sensitive color-changing layer is arranged in the lamination direction of ultrasonic welding of the electrode lug and the current collector, the pressure-sensitive color-changing layer can change in color along with the pressure. After the electrode lug and the current collector are ultrasonically welded, the pressure-sensitive color-changing layer can reflect the pressure conditions of the electrode lug and the current collector through colors. And observing the color of the pressure-sensitive color-changing layer to identify whether the phenomena of uneven pressure, insufficient pressure and the like exist. Through the recognition to the pressurized condition, can judge the ultrasonic welding condition, it is simple and convenient, little to the production process influence, reduce product later stage reworking and defective rate, improve product production efficiency. Meanwhile, the color of the pressure-sensitive color-changing layer is compared, and the soft-package battery core of the local cold joint or the whole cold joint is screened out, so that the safety performance of a soft-package battery core product can be improved, and the subsequent potential safety hazard is reduced.

Drawings

Fig. 1 is a schematic perspective view of a soft-package battery cell according to an embodiment of the utility model.

Fig. 2 is a schematic structural diagram of a connection position between a current collector and a tab according to an embodiment of the present utility model.

Fig. 3 is a schematic structural diagram of a connection position between a current collector and a tab according to an embodiment of the present utility model.

Fig. 4 is a schematic structural diagram illustrating a connection position between a current collector and a tab according to an embodiment of the present utility model.

Fig. 5 is a schematic structural diagram illustrating a connection position between a current collector and a tab according to an embodiment of the present utility model.

Fig. 6 is a schematic structural diagram of a connection position between a current collector and a tab according to an embodiment of the present utility model.

Fig. 7 is a schematic structural diagram illustrating a connection position between a current collector and a tab according to an embodiment of the present utility model.

Reference numerals illustrate: the battery cell comprises a battery cell body 1, a current collector 2, a tab 3, a pressure-sensitive color-changing layer 4, a protection sheet 5 and sealant 6.

Detailed Description

Further advantages and effects of the present utility model will become apparent to those skilled in the art from the disclosure of the present utility model, which is described by the following specific examples.

Please refer to fig. 1 to 7. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or otherwise, used in the practice of the utility model, are not intended to be critical to the essential characteristics of the utility model, but are intended to fall within the spirit and scope of the utility model. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the utility model, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the utility model may be practiced.

Referring to fig. 1 to 4, a soft package battery cell of the present embodiment includes a battery cell body 1 and a tab 3, wherein the battery cell body 1 extends to form a current collector 2, and the tab 3 is connected with the current collector 2 by ultrasonic welding. In the lamination direction of ultrasonic welding of the tab 3 and the current collector 2, a pressure-sensitive color-changing layer 4 is arranged on one side of the current collector 2 away from the tab 3 and/or one side of the tab 3 away from the current collector 2. In this embodiment, the current collector 2 and the tab 3 are both sheet-shaped, and the current collector 2 and the tab 3 are stacked and then parallel to each other. During ultrasonic welding, the current collector 2 and the electrode lug 3 are pressed along the direction vertical to the current collector 2 or the electrode lug 3, and the pressing direction of ultrasonic welding is vertical to the current collector 2 or the electrode lug 3. After the ultrasonic welding is finished, the color of the pressure-sensitive color-changing layer 4 can be compared with a color card prepared in advance, different pressures can be represented by the same color on the color card, and the pressure values of all areas on the pressure-sensitive color-changing layer 4 can be obtained through comparison, so that risks such as cold welding, off-welding and the like are judged. The ultrasonic welding condition is judged by identifying the pressed condition, so that the ultrasonic welding method is simple and convenient, the influence on the production process is small, the post reworking and reject ratio of the product are reduced, and the production efficiency is improved. Meanwhile, the soft package battery core with partial or whole cold joint is selected, so that the safety performance of the soft package battery core can be improved, and the subsequent potential safety hazard is reduced.

Specifically, as shown in fig. 2, in some embodiments, the pressure-sensitive color-changing layer 4 may be disposed on a side of the current collector 2 remote from the tab 3. In actual production process, the current collector 2 is usually located above the tab 3, and the pressure-sensitive color-changing layer 4 is arranged on one side of the current collector 2 away from the tab 3, that is, above the current collector 2, so that the color of the pressure-sensitive color-changing layer 4 can be conveniently observed and compared after ultrasonic welding, and the observation efficiency can be improved. As shown in fig. 3, in other embodiments, the pressure-sensitive color-changing layer 4 may also be disposed on the side of the tab 3 away from the current collector 2, that is, below the tab 3. As shown in fig. 4, in still other embodiments, a pressure sensitive color-changing layer 4 is disposed on both a side of the current collector 2 away from the tab 3 and a side of the tab 3 away from the current collector 2. After ultrasonic welding, pressure ratio comparison results can be obtained from the two pressure-sensitive color-changing layers 4 respectively, and comprehensive judgment can be performed by combining the pressure ratio comparison results of the two pressure-sensitive color-changing layers 4, so that judgment accuracy of risks such as false welding and desoldering can be improved.

As shown in fig. 5 to 7, in some embodiments, a protection sheet 5 is disposed on a side of the current collector 2 away from the tab 3, and during ultrasonic welding, the protection sheet 4 is used for protecting the current collector 2 during ultrasonic welding, and the protection sheet 5 can prevent the ultrasonic welding head from piercing the current collector 2, so as to protect the current collector 2. As shown in fig. 5 to 7, the protective sheet 5, the current collector 2, and the tab 3 are laminated in this order from top to bottom.

As shown in fig. 5, in some embodiments, when the pressure-sensitive color-changing layer 4 is disposed on the side of the current collector 2 away from the tab 3, the pressure-sensitive color-changing layer 4 may be disposed on the side of the protective sheet 5 away from the current collector 2, i.e., above the protective sheet 5, i.e., the protective sheet 5 is located between the current collector 2 and the pressure-sensitive color-changing layer 4. Since the current collector 2 is generally placed above the tab 3 during ultrasonic welding, the protective sheet 5 is above the current collector 2. Therefore, when the pressure-sensitive color-changing layer 4 is arranged above the protective sheet 5, the color of the pressure-sensitive color-changing layer 4 can be observed and compared without turning after ultrasonic welding, and the method is simple and convenient.

As shown in fig. 6, in some embodiments, when the protective sheet 5 is provided on the side of the current collector 2 away from the tab 3, the pressure-sensitive color-changing layer 4 may also be provided on the side of the tab 3 away from the current collector 2, that is, below the tab 3.

As shown in fig. 7, in other embodiments, the side of the protection sheet 5 away from the current collector 2 and the side of the tab 3 away from the current collector 2 are both provided with pressure sensitive color change layers 4, after ultrasonic welding, pressure ratio pairs can be obtained from the two pressure sensitive color change layers 4 respectively, and by combining the pressure ratio pairs of the two pressure sensitive color change layers 4, comprehensive judgment is performed, so that judgment accuracy of risks such as cold welding and desoldering can be improved.

Specifically, in some embodiments, the pressure-sensitive color-changing layer 4 may be coated with a pressure-sensitive color-changing material, and the pressure-sensitive color-changing coating is formed after coating. The coating setting is simple and convenient, and the production efficiency is high. When the pressure-sensitive color-changing layer 4 is a pressure-sensitive color-changing coating, the thickness of the pressure-sensitive color-changing coating may be 0.01mm to 0.05mm. For example, the thickness of the pressure sensitive color-changing coating may be 0.02mm.

In other embodiments, the pressure-sensitive color-changing layer 4 comprises a base layer, and a plurality of accommodating holes are formed in the base layer, and the accommodating holes are filled with pressure-sensitive color-changing materials. The base layer plays a role in protecting and connecting the pressure-sensitive color-changing material filled in the accommodating hole, the pressure-sensitive color-changing material in the accommodating hole is not easy to fall off, and the pressure-sensitive color-changing layer 4 can be well connected to the electrode lug 3 or the current collector 2 after being arranged.

Specifically, the porosity of the accommodation hole may be 10% to 60%, for example, the porosity of the accommodation hole may be 50%. The thickness of the base layer is 0.1 mm-0.2 mm. For example, the thickness of the base layer may be 0.15mm.

In practical cases, the porosity of the accommodating hole and the thickness of the base layer can be reasonably selected by combining the properties of the base layer material, the properties of the pressure-sensitive color-changing material, the size of ultrasonic welding pressure force and the like, so as to obtain a better color-changing effect. Specifically, the base layer can be made of porous copper or porous aluminum, and the copper and aluminum have good conductivity and are easy to process.

The material of the pressure-sensitive color-changing layer 4 can comprise one or more of vinyl compounds, amide polymers and metal halogenated organic compounds.

In some embodiments, the material of the pressure-sensitive color-changing layer 4 is a single material, for example, one of an alkene compound, an amide polymer or a metal halogenated organic compound, and may be any ratio mixture of at least two of the alkene compound, the amide polymer or the metal halogenated organic compound. As the vinyl compound, the amide polymer or the metal halogenated organic compound are all pressure-sensitive color-changing materials, any proportion mixture of at least two of the vinyl compound, the amide polymer or the metal halogenated organic compound also has pressure-sensitive color-changing performance.

In other embodiments, the pressure-sensitive color-changing layer 4 may be divided into two or more color-changing areas, and one or more of an alkene compound, an amide polymer or a metal halogenated organic compound may be disposed in the color-changing areas, and at least one of the color-changing areas has a material different from that of the other color-changing areas. For example, the risk of occurrence of cold joint in the middle of the pressure sensitive color change layer 4 is high, while the risk of occurrence of cold joint at the edge of the pressure sensitive color change layer 4 is low. Therefore, the pressure-sensitive color-changing layer 4 can be divided into a middle area and an edge area, the pressure-sensitive color-changing material which is sensitive to pressure can be arranged in the middle area of the pressure-sensitive color-changing layer 4, and the pressure-sensitive color-changing material which is relatively insensitive to pressure is arranged in the edge area, so that better pressure display effect and cost performance are obtained.

The soft package battery cell can also include the casing, and electric core body 1 holds in the casing, and current collector 2 connects on the one end of utmost point ear 3, and the other end of utmost point ear 3 wears in the casing. In this embodiment, the housing is an aluminum plastic film. The electrode lug 3 is provided with a sealant 6, and the electrode lug 3 and the shell are sealed by the sealant 6.

The sealant 6 can play an insulating role, and short circuit between the tab 3 and the aluminum plastic film is prevented when the soft package battery cell is packaged. When the soft package battery core is packaged, the sealant 6 can be bonded with the aluminum plastic film by hot melting and sealing through heating the sealant 6, so that liquid leakage is prevented.

In summary, according to the soft-package battery core of the embodiment, since the pressure-sensitive color-changing layer 4 is arranged in the lamination direction of ultrasonic welding of the tab 3 and the current collector 2, the pressure-sensitive color-changing layer 4 can change in color along with the applied pressure, after ultrasonic welding of the tab 3 and the current collector 2, whether the phenomenon of uneven pressure exists can be identified by observing the color of the pressure-sensitive color-changing layer 4, the welding condition between the current collector 2 and the tab 3 is identified, simplicity and convenience are realized, the influence on the production process is small, the post-rework and the reject ratio of products are reduced, and the production efficiency is improved. Meanwhile, the soft package battery core with partial or whole cold joint is selected, so that the safety performance of the soft package battery core can be improved, and the subsequent potential safety hazard is reduced.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (10)

1. The utility model provides a soft packet of electric core which characterized in that: the battery cell comprises a battery cell body and a tab, wherein the battery cell body extends to form a current collector, and the tab is connected with the current collector by ultrasonic welding;

and in the lamination direction of ultrasonic welding of the electrode lug and the current collector, a pressure-sensitive color-changing layer is arranged on one side of the current collector away from the electrode lug and/or one side of the electrode lug away from the current collector.

2. The soft pack cell of claim 1, wherein: and when the pressure sensitive color-changing layer is arranged on one side of the current collector, which is far away from the electrode lug, the pressure sensitive color-changing layer is arranged on one side of the protection sheet, which is far away from the current collector.

3. The soft pack cell of claim 1, wherein: the pressure-sensitive color-changing layer is a pressure-sensitive color-changing coating which is arranged in a coating way.

4. A soft pack cell according to claim 3, wherein: the thickness of the pressure-sensitive color-changing coating is 0.01 mm-0.05 mm.

5. The soft pack cell of claim 1, wherein: the pressure-sensitive color-changing layer comprises a base layer, a plurality of containing holes are formed in the base layer, and pressure-sensitive color-changing materials are filled in the containing holes.

6. The soft pack cell of claim 5, wherein: the porosity of the accommodating hole is 10% -60%.

7. The soft pack cell of claim 5, wherein: the thickness of the base layer is 0.1 mm-0.2 mm.

8. The soft pack cell according to any one of claims 1 to 7, wherein: the pressure-sensitive color-changing layer is made of vinyl compounds, amide polymers or metal halogenated organic compounds.

9. The soft pack cell according to any one of claims 1 to 7, wherein: the pressure-sensitive color-changing layer comprises two or more color-changing areas, and the material of at least one color-changing area is different from the material of the other color-changing areas.

10. The soft pack cell according to any one of claims 1 to 7, wherein: the battery cell comprises a battery cell body, a current collector and a lug, wherein the battery cell body is accommodated in the battery cell body, the current collector is connected to one end of the lug, and the other end of the lug penetrates through the battery cell body.