Soft package battery cell, battery module, battery pack and vehicle

Abstract

The utility model discloses a soft package battery cell, a battery module, a battery pack and a vehicle. The soft package battery cell comprises a first shell and a second shell, a partition assembly is arranged between the first shell and the second shell, the containing space of the battery cell shell is divided into a first containing cavity and a second containing cavity, the partition assembly is provided with meshes, a pole group assembly of the battery cell is arranged in the first containing cavity, and a lithium supplementing assembly is arranged in the second containing cavity. The separation assembly is arranged between the first shell and the second shell of the soft package battery cell, the battery cell pole group assembly and the lithium supplementing assembly are separated, the lithium supplementing assembly is internally supported and protected through the separation assembly, and short circuit caused by mutual extrusion and friction of the lithium supplementing assembly and the pole group assembly is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a soft-pack battery cell, a battery module, a battery pack and a vehicle. Background Art

[0002] Lithium-ion batteries have the characteristics of high voltage, high specific energy and long life, and are widely used in new energy vehicles, energy storage and other industries. For the negative electrode of the lithium-ion battery, part of the lithium ions will be consumed during the first charging process of the battery due to the formation of the solid electrolyte membrane (SEI membrane); although this layer of membrane is beneficial to the cycle stability of the positive and negative electrode materials, it will cause lithium loss in part of the positive electrode material, resulting in a decrease in the first coulomb efficiency, thereby reducing the capacity of the battery, especially in negative electrode materials with high specific capacity (such as silicon oxide materials); so how to reduce or compensate for the consumption of lithium ions during the formation of the SEI membrane has always been the goal of researchers. In the prior art, the consumed lithium ions are supplemented by setting a lithium metal electrode in the soft-pack battery cell, but there are problems with the setting of the lithium metal electrode. The lithium metal electrode will squeeze the battery cell electrode group or rub against the battery cell electrode group to cause a short circuit. Utility Model Content

[0003] The embodiment of the utility model provides a soft-pack battery cell to solve the problems existing in the arrangement of lithium metal electrodes in the prior art.

[0004] On one hand, an embodiment of the utility model provides a soft-pack battery cell, a shell, comprising a first shell and a second shell, wherein the first shell and the second shell are sealed and connected to form an accommodating space;

[0005] A partition component is disposed between the first shell and the second shell to divide the accommodating space into a first accommodating chamber and a second accommodating chamber, and the partition component has a mesh connecting the first accommodating chamber and the second accommodating chamber;

[0006] An electrode group assembly, the electrode group assembly is arranged in the first accommodating cavity, the electrode group assembly comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet is connected to the positive electrode tab of the soft-pack battery cell, and the negative electrode sheet is connected to the negative electrode tab of the soft-pack battery cell;

[0007] A lithium supplement component is disposed in the second accommodating cavity, and an electrode of the lithium supplement component is connected to a third electrode tab of the soft-pack battery cell.

[0008] In some embodiments, the partition component is an aluminum-plastic film, including a first polyolefin film layer, a first adhesive layer, an aluminum foil layer, a second adhesive layer and a second polyolefin film layer stacked in sequence, the mesh penetrates the aluminum-plastic film, the partition component is sandwiched between the first shell and the second shell, and the edge of the partition component is heat-sealed between the first shell and the second shell.

[0009] In some embodiments, the thickness of the first polyolefin film layer and the second polyolefin film layer is 40 μm-120 μm, the thickness of the aluminum foil layer is 20 μm-100 μm, and the thickness of the first adhesive layer and the second adhesive layer is 1 μm-10 μm.

[0010] In some embodiments, the first adhesive layer and the second adhesive layer are modified polyolefin or epoxy resin.

[0011] In some embodiments, the mesh size of the mesh is 100-200 mesh.

[0012] In some embodiments, the lithium supplement component includes a copper foil layer, a lithium metal layer disposed on both sides of the copper foil layer, and a diaphragm layer covering the lithium metal layer.

[0013] In some embodiments, the pole group assembly is a laminated pole group or a wound pole group.

[0014] On the other hand, the utility model also provides a battery module.

[0015] Another aspect of the utility model further provides a battery pack.

[0016] Another aspect of the utility model provides a vehicle.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] The soft-pack battery provided by the embodiment of the utility model separates the battery cell pole group component from the lithium supplement component by setting a partition component between the first shell and the second shell of the soft-pack battery cell, and the lithium supplement component is internally supported and protected by the partition component to prevent the lithium supplement component and the pole group component from short-circuiting due to mutual extrusion and friction. The overall structure is simple, the current production process of the soft-pack battery cell is less modified, it is safe and easy to operate, and can be mass-produced industrially. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the cross-sectional structure of a soft-pack battery cell provided in one embodiment of the utility model;

[0020] Figure 2 It is a schematic diagram of the cross-sectional structure of a partition assembly provided in one embodiment of the utility model;

[0021] Figure 3 It is a schematic diagram of the cross-sectional structure of a lithium replenishing assembly provided in one embodiment of the utility model.

[0022] Notes on the attached drawings:

[0023] 1. Shell; 11. First shell; 12. Second shell; 13. Accommodation space; 131. First accommodation cavity; 132. Second accommodation cavity; 2. Separation component; 21. Mesh; 22. Aluminum foil layer; 23. Polyolefin film layer; 24. Adhesive layer; 3. Pole group component; 4. Lithium supplement component; 41. Copper foil layer; 42. Lithium metal layer; 43. Diaphragm; 5. Positive electrode ear; 6. Negative electrode ear; 7. Third electrode ear. DETAILED DESCRIPTION

[0024] Many specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific implementation disclosed below.

[0025] See also Figure 1-3 As shown, the embodiment of the utility model discloses a soft-pack battery cell, which has a shell 1, a separator component 2, an electrode group component 3, a lithium supplement component 4, a positive electrode tab 5, a negative electrode tab 6 and a third electrode tab 7. The shell 1 includes a first shell 11 and a second shell 12. The first shell 11 and the second shell 12 are made of aluminum-plastic film. Through the aluminum-plastic film punching process, a receiving groove is punched out on the first shell 11 and the second shell 12. The first shell 11 and the second shell 12 are connected to each other with the receiving groove to form a receiving space 13. The separator component 2 is sandwiched between the first shell 11 and the second shell 12, and the receiving space 13 of the shell 1 is divided into a first receiving chamber 131 and a second receiving chamber 132. The separator component 2 has a mesh 21 connecting the first receiving chamber 131 and the second receiving chamber 132, and the electrolyte in the soft-pack battery cell can pass through the mesh 21. The separator component 2 is an aluminum-plastic film, and the edge of the separator component 2 is hot-pressed and packaged with the edge of the first shell 11 and the second shell 12. The electrode assembly 3 is a laminated electrode assembly structure or a wound electrode assembly structure, and is disposed in the first accommodation chamber 131. The electrode assembly 3 includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet of the electrode assembly 3 is connected to the positive electrode tab 5 of the soft-pack battery cell, and the negative electrode sheet of the electrode assembly 3 is connected to the negative electrode tab 6 of the soft-pack battery cell. The lithium supplement component 4 is disposed in the second accommodation chamber 132. The lithium supplement component 4 includes a lithium source, and the electrode of the lithium supplement component 4 is connected to the third electrode tab 7 of the soft-pack battery cell. When the battery cell is packaged, the tab glue of the positive electrode tab 5, the negative electrode tab 6 and the third electrode tab 7 is hot-pressed and packaged together with the separator component 2 and the edges of the first shell 11 and the second shell 12.

[0026] In the above embodiment, the material of the shell 1 is the aluminum-plastic film conventionally used in existing soft-pack batteries, which will not be further described here. The partition component 2 is a new aluminum-plastic film, including an aluminum foil layer 22 and a polyolefin film layer 23 bonded to the surfaces of both sides of the aluminum foil layer, specifically a cast polypropylene film layer. Between the aluminum foil layer 22 and the polyolefin layer 23 is an adhesive layer 24, which includes at least one of a modified polyolefin and an epoxy resin.

[0027] Furthermore, the thickness of the aluminum foil layer 22 is 20 μm-100 μm, the thickness of the polyolefin film layer 23 is 40 μm-120 μm, and the thickness of the adhesive layer 24 is 1 μm-10 μm.

[0028] In the above embodiment, the lithium supplement component 4 includes a copper foil layer 41, a lithium metal layer 42 plated on both sides of the copper foil layer 41, and a diaphragm layer 43 covering the lithium metal layer 42. The copper foil layer 41 is connected to the third electrode tab 7.

[0029] In the above embodiment, the mesh number of the mesh 23 of the separation component 2 is 100 to 200 meshes, and the aperture of the mesh 23 does not affect the transmission of the electrolyte in the first accommodating chamber 131 and the second accommodating chamber 132. The electrolyte can pass through the isolation component 4, and when the lithium replenishment operation is performed, the lithium metal layer 42 in the lithium replenishment component 4 releases lithium ions that can enter one side of the soft-pack battery cell electrode group component 3 through the electrolyte, thereby replenishing the negative electrode of the soft-pack battery cell.

[0030] In the above embodiment, when lithium is replenished, the third electrode tab 7 of the soft-pack battery cell is connected to the negative electrode of the power supply, and the negative electrode tab of the soft-pack battery cell is connected to the positive electrode of the power supply. After the soft-pack battery cell is charged and discharged, the middle negative electrode plate of the soft-pack battery cell is pre-lithiated.

[0031] The utility model also provides a battery module, in which the battery cells are the soft-pack battery cells in the above embodiment.

[0032] The utility model also provides a battery pack, which includes the battery module in the above embodiment.

[0033] The utility model also provides a vehicle, which uses the battery pack described in the above embodiment.

[0034] The utility model can at least achieve the following beneficial effects:

[0035] By setting a partition component between the first shell and the second shell of the soft-pack battery cell, the soft-pack battery cell electrode group component is separated from the lithium supplement component, and the lithium metal electrode of the lithium supplement component is internally supported and protected by the partition component to prevent the lithium metal electrode and the stacked core from short-circuiting due to mutual extrusion and friction. The overall structure is simple, with little change to the current production process of soft-pack batteries, safe and easy to operate, and can be mass-produced industrially.

[0036] It should be noted that although the utility model is disclosed as above in the form of a preferred embodiment, it is not intended to limit the utility model. Any technical personnel in this field may make possible changes and modifications without departing from the spirit and scope of the utility model. Therefore, the scope of protection of the utility model shall be based on the scope defined by the claims of the utility model.

Claims

1. A soft-pack battery cell, characterized in that: include: The housing comprises a first housing and a second housing, wherein the first housing and the second housing are sealed and butted against each other to form an accommodating space; A partition component is disposed between the first shell and the second shell to divide the accommodating space into a first accommodating chamber and a second accommodating chamber, and the partition component has a mesh connecting the first accommodating chamber and the second accommodating chamber; An electrode group assembly, the electrode group assembly is arranged in the first accommodating cavity, the electrode group assembly comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet is connected to the positive electrode tab of the soft-pack battery cell, and the negative electrode sheet is connected to the negative electrode tab of the soft-pack battery cell; A lithium supplement component is disposed in the second accommodating cavity, and an electrode of the lithium supplement component is connected to a third electrode tab of the soft-pack battery cell.

2. The soft-pack battery cell according to claim 1, characterized in that: The partition component is an aluminum-plastic film, including a first polyolefin film layer, a first adhesive layer, an aluminum foil layer, a second adhesive layer and a second polyolefin film layer stacked in sequence, the mesh penetrates the aluminum-plastic film, the partition component is sandwiched between the first shell and the second shell, and the edge of the partition component is heat-sealed between the first shell and the second shell.

3. The soft-pack battery cell according to claim 2, characterized in that: The thickness of the first polyolefin film layer and the second polyolefin film layer is 40 μm-120 μm, the thickness of the aluminum foil layer is 20 μm-100 μm, and the thickness of the first adhesive layer and the second adhesive layer is 1 μm-10 μm.

4. The soft-pack battery cell according to claim 2, characterized in that: The first adhesive layer and the second adhesive layer are modified polyolefin or epoxy resin.

5. The soft-pack battery cell according to claim 2, characterized in that: The mesh size of the mesh is 100-200 meshes.

6. The soft-pack battery cell according to claim 1, characterized in that: The lithium supplement component comprises a copper foil layer, lithium metal layers arranged on both sides of the copper foil layer, and a diaphragm layer covering the lithium metal layers.

7. The soft-pack battery cell according to claim 1, characterized in that: The pole group assembly is a laminated pole group or a wound pole group.

8. A battery module, characterized in that: Comprising the soft-pack battery cell according to any one of claims 1 to 7.

9. A battery pack, characterized in that: It comprises the soft-pack battery cell according to any one of claims 1 to 7 or the battery module according to claim 8.

10. A vehicle, characterized in that: Comprising the battery pack according to claim 9.

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