Battery

Abstract

The utility model provides a battery, which is applied to the technical field of batteries, and in particular relates to a battery, which comprises a battery cell, a shell and a tab positioned on the battery cell, the shell wraps the battery cell to form a battery body; the shell comprises a protective layer, a metal layer and an insulating layer which are stacked in sequence; the shell comprises a first shell layer and a second shell layer, and the first shell layer and the second shell layer are attached to form a side sealing edge located on at least one side of the battery body and a top sealing edge located on one side of the tab; the side sealing edge comprises a first edge part which is folded towards the direction close to the battery body, the protective layer on one side, close to the battery body, of the first edge part forms a first blank area which exposes the metal layer, and an adhesive layer is arranged between the first blank area and the battery body. One side, close to the battery body, of the first edge part is provided with the first blank area, and a protective layer is not arranged, so that a bonded metal layer is directly exposed, and the fixing strength of the side sealing edge and the battery body can be effectively improved; the protection layer is removed to reduce the width of the battery body and improve the energy density of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery. Background Art

[0002] When packaging lithium batteries, the aluminum-plastic film is folded together to completely wrap the lithium battery cell, while the pole ear of the lithium battery cell is extended, and then the folded aluminum-plastic film is sealed by heat sealing to fuse the insulating heat-sealing layer of the aluminum-plastic film together to form a sealing edge, and then the excess sealing edge is cut to remove the excess part.

[0003] In order to ensure edge sealing insulation and improve battery volume space utilization, the commonly used effective processes are:

[0004] The edge seal is folded up along the side edge seal of the lithium battery body and then adhered to the battery body with an adhesive, and then the battery edge seal end face is insulated with an insulating adhesive layer.

[0005] However, the above process still has the following problems: during use, due to the decrease in the adhesion of the adhesive layer, the battery edge seal is not firmly fixed to the body, and the edge seal opens; in addition, although the folding of the side seal along the body can effectively reduce the width of the battery, there is still room for optimization of the width. Utility Model Content

[0006] In view of this, the present application provides a battery, which improves the fixing strength of the side seal and the battery body, reduces the width of the battery body, and improves the battery energy density by removing the protective layer on the surface of the side where the side seal is bonded to the battery body to expose the metal layer.

[0007] In order to achieve the above objectives, this application provides the following technical solutions:

[0008] A battery comprises a battery cell, a shell and a tab on the battery cell;

[0009] The shell wraps the battery core to form a battery body;

[0010] The shell comprises a protective layer, a metal layer and an insulating layer which are stacked in sequence;

[0011] The shell comprises a first shell layer and a second shell layer, wherein the first shell layer and the second shell layer are attached to form a side seal located on at least one side of the battery body and a top seal located on one side of the tab;

[0012] The side seal includes a first edge portion folded toward the battery body, the protective layer on the side of the first edge portion close to the battery body forms a first blank area exposing the metal layer, and an adhesive layer is arranged between the first blank area and the battery body.

[0013] Optionally, one end of the first blank area in the first direction extends at least to the edge of the top seal, and the other end of the first blank area in the first direction is flush with the edge of the side seal in the first direction.

[0014] Optionally, the first blank area is arranged along the first direction of the side edge seal, and a size of the first blank area in the second direction is smaller than a size of the side edge seal in the second direction.

[0015] Optionally, the side edge seal includes a bent portion located between the battery body and the first edge portion;

[0016] An end of the first blank area close to the battery body does not exceed the bent portion.

[0017] Optionally, the size of the first blank area in the second direction is W1, the size of the side edge seal in the second direction is W2, and the relationship between W1 and W2 satisfies W1:W2≥60%; and / or,

[0018] The area of ​​the first blank area is S1, the area of ​​the side edge seal is S2, and the relationship between S1 and S2 satisfies S1:S2≥60%.

[0019] Optionally, an insulating adhesive layer is provided at the outer edge of the side edge seal in the second direction, and the insulating adhesive layer completely covers the cross section of the outer edge of the side edge seal.

[0020] Optionally, the insulating adhesive layer and the first blank area at least partially overlap.

[0021] Optionally, the side edge seal includes a second edge connecting the first edge and the battery body, and the second edge is located on a side of the first edge away from the battery body.

[0022] Optionally, the side edge seal includes a bent portion between the first edge portion and the second edge portion, and an end portion of the first blank area does not exceed the bent portion.

[0023] Optionally, the adhesive layer covers the end surface of the side edge seal.

[0024] Optionally, a second blank area exposing the metal layer is further provided on a surface of the first edge portion close to the second edge portion, and the adhesive layer is provided on the second blank area.

[0025] Optionally, a size of the second blank area in the second direction is greater than a size of the first blank area in the second direction.

[0026] Optionally, the bonding force between the battery body and the adhesive layer is smaller than the bonding force between the adhesive layer and the side sealing edge.

[0027] Optionally, the bonding force between the battery body and the adhesive layer is F1, and the value of F1 satisfies: F1≥0.5N / mm; and / or the bonding force between the adhesive layer and the side edge seal is F2, and the value of F2 satisfies: F2≥1N / mm.

[0028] The battery provided in the present application has a first blank area on the surface of one side of the first edge of the side seal close to the battery body, so that there is no protective layer, and the metal layer of the shell is directly exposed to the outside. The metal layer is more conducive to bonding than the protective layer, and can effectively improve the fixing strength of the side seal of the battery and the battery body; in addition, since the protective layer is removed, the width of the battery body can also be reduced to a certain extent, thereby improving the battery energy density. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] Figure 1 It is a schematic diagram of the aluminum-plastic film structure in the prior art;

[0031] Figure 2 It is a schematic diagram of the battery cell & aluminum-plastic film assembly in the prior art;

[0032] Figure 3 It is a top view of a battery after packaging in the prior art;

[0033] Figure 4 It is a cross-sectional view of a battery after packaging and folding in the prior art;

[0034] Figure 5 It is a cross-sectional view of a battery after packaging in the prior art;

[0035] Figure 6 This is a schematic diagram of the edge sealing insulation protection layer after laser removal in this application;

[0036] Figure 7 This is a top view of the insulating protective layer of the edge seal in this application after being removed by laser;

[0037] Figure 8 It is a cross-sectional schematic diagram of a battery after laser cleaning in this application;

[0038] Fig. 9 Schematic diagram of the sealing edges of the front and back of the double-folded battery in this application;

[0039] Fig.10 It is a cross-sectional schematic diagram of the double-folded battery in this application.

[0040] exist Figure 1-Figure 10 middle:

[0041] 1. Shell; 11. Protective layer; 12. Metal layer; 13. Insulating layer; 2. Battery cell; 3. Tab; 4. Top edge seal; 5. Side edge seal; 51. First blank area; 52. Second blank area; 53. First edge; 54. Second edge; 55. Bending part; 6. Insulating adhesive layer; 7. Adhesive layer. DETAILED DESCRIPTION

[0042] The present application provides a side sealing structure for a battery, which improves the fixing strength between the side sealing and the battery body, reduces the width of the battery body, and improves the battery energy density by removing the insulating protective layer on the surface of the side where the side sealing is bonded to the battery body to expose the metal layer.

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only 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 creative work are within the scope of protection of this application.

[0044] In the prior art, soft-package lithium batteries are widely used because their shells use relatively thin and soft aluminum-plastic films. Compared with traditional metal shell batteries, soft-package lithium batteries have the advantages of easy processing and high energy density. Figure 1 As shown, the aluminum-plastic film of the soft-package lithium battery is generally a composite film 1 , which includes an insulating protective layer 11 , a metal layer 12 and an insulating layer 13 , wherein the metal layer 12 is located between the insulating protective layer 11 and the insulating layer 13 .

[0045] like Figure 2-3 As shown, when packaging the soft-package lithium battery, the aluminum-plastic film is folded together to completely wrap the lithium battery cell 2, while allowing the electrode ear 3 of the lithium battery cell 2 to extend, and then the folded aluminum-plastic film is sealed by heat sealing to fuse the insulating layer 13 of the aluminum-plastic film together to form a sealed edge, and then the excess sealed edge is cut to remove the excess part.

[0046] like Figure 4 As shown, in order to ensure the insulation performance of the edge seal and improve the volume space utilization of the lithium battery, the effective process usually adopted is: fold the edge seal along the side of the lithium battery body and then stick it to the battery body with an adhesive, and then use an insulating glue layer 6 to insulate the end face of the battery side edge seal 5.

[0047] like Figure 5-8As shown, the battery provided in the present application includes a battery cell 2 and a shell 1 wrapping the battery cell 2. In this embodiment, the shell 1 is a flexible composite film, and a tab 3 is also provided on the battery cell. The shell 1 wraps the battery cell 2 to form a battery body. Figure 5 For example, the battery body includes a bottom surface ( Figure 5 The side facing the paper), the front side (i.e. Figure 5 The upper end face of the battery body), the reverse side (i.e. Figure 5 The lower end face of the battery body), the top face opposite to the bottom face (the side facing away from the paper, i.e. the end face from which the tab 3 extends) and the two side faces (i.e. Figure 5 The left and right end faces of the battery body);

[0048] The housing 1 comprises an insulating protective layer 11, a metal layer 12 and an insulating layer 13 which are stacked in sequence;

[0049] The shell 1 includes a first shell layer (i.e., the shell 1 part on the front side of the battery body) and a second shell layer (i.e., the shell 1 part on the back side of the battery body), and the first shell layer and the second shell layer are attached to form side seals located on the two sides of the battery body and a top seal located on the side of the pole ear;

[0050] The side sealing edge includes a first edge portion folded toward the direction close to the battery body, a first blank area exposing the metal layer is formed on the protective layer of the first edge portion close to the battery body, and an adhesive layer is arranged between the first blank area and the battery body;

[0051] The battery of the present application has a first blank area 51 provided on the surface of one side of the first edge close to the battery body, so that there is no protective layer 11, and the metal layer 12 of the shell 1 is directly exposed to the outside. The metal layer 12 is more conducive to bonding than the protective layer 11, and can effectively improve the fixing strength of the bonding between the first edge of the side seal 5 and the battery body; in addition, since the protective layer 11 is removed, the width of the battery body can also be reduced to a certain extent, thereby improving the battery energy density.

[0052] like Figure 7 As shown in the figure, the X direction is the first direction, the Y direction is the second direction, the length direction of the side seal 5 - the direction from the top surface to the bottom surface of the battery body, is the same as the first direction, and the width direction of the side seal 5 - the direction from one side surface to the other side surface of the battery body, is the same as the second direction; the length direction and width direction of the first blank area 51 set on the side seal 5 are also consistent with the length direction and width direction of the side seal 5 respectively;

[0053] In a preferred embodiment, one end of the first blank area 51 in the first direction at least extends to the edge of the top seal 4 on the side seal side, and the other end of the first blank area 51 in the first direction is flush with the edge of the side seal 5 in the first direction.

[0054] like Figure 7 As shown in the left figure, the first blank area 51 at one end in the first direction at least extends to the edge of the top sealing edge 4 on the side of the side sealing edge, that is, the lower edge of the top sealing edge 4; that is, the length of the first blank area 51 can run through the entire side sealing edge 5 to the upper edge of the top sealing edge 4, or only to the lower edge of the top sealing edge 4; preferably, as Figure 7 As shown in the right figure, the first blank area 51 only extends to the lower edge of the top sealing edge 4. This is because if the protective layer 11 at the top sealing edge 4 is removed, the insulation function will be lost, and an additional insulating glue layer 6 is required to ensure its insulation.

[0055] like Figure 6-7 As shown, preferably, the first blank area 51 is arranged along the length direction of the side edge seal 5 , and the width of the first blank area 51 is smaller than the width of the side edge seal 5 .

[0056] In order to ensure the insulation of the connection between the battery body and the side seal 5 , a portion of the protection layer 11 is retained at the connection between the battery body and the side seal 5 . Therefore, the width of the first blank area 51 is smaller than the width of the side seal 5 .

[0057] Specifically, the side edge seal 5 includes a bent portion located between the battery body and the first edge portion, and the bent portion is also the connection between the battery body and the side edge seal 5;

[0058] The end of the first blank area 51 close to the battery body does not exceed the bent portion, so that the insulation of the connection between the battery body and the side sealing edge 5 can be ensured.

[0059] In a preferred embodiment, the width of the first blank area 51 is W1, the width of the side edge seal 5 is W2, and the relationship between W1 and W2 satisfies W1:W2≥60%; the area of ​​the first blank area 51 is S1, the width of the side edge seal 5 is S2, and the relationship between S1 and S2 satisfies S1:S2≥60%.

[0060] In this way, the insulation of the connection between the battery body and the side sealing edge 5 can be ensured, and the first blank area 51 and the battery body can have sufficient bonding width and bonding area, thereby ensuring the bonding strength between the side sealing edge 5 and the battery body.

[0061] like Figure 8 As shown, in a preferred embodiment, an insulating adhesive layer 6 is provided at the outer edge of the side edge seal 5 in the width direction, and the insulating adhesive layer 6 completely covers the cross section of the outer edge of the side edge seal 5 .

[0062] In order to ensure the insulation performance at the cross section of the outer edge of the side sealing edge 5 in the width direction, an insulating rubber layer 6 is provided at the cross section.

[0063] Furthermore, in a preferred embodiment, the insulating rubber layer 6 and the first blank area 51 at least partially overlap. This is because the first blank area 51 is flush with the outer edge of the side edge seal 5 in the width direction, and the insulation performance of this area also needs to be considered. Therefore, while the insulating rubber layer 6 is provided at the cross section of the outer edge of the side edge seal 5 in the width direction, the insulating rubber layer 6 is also extended to the outer edge of the first blank area 51 in the width direction.

[0064] In another preferred embodiment, Fig.10 As shown, the battery is a double-folded battery, and the side sealing edge includes, in addition to the first edge as in the above embodiment, a second edge connecting the first edge and the battery body, and the second edge is located on the side of the first edge away from the battery body. The protective layer on the side of the first edge close to the battery body is formed with a first blank area 51 exposing the metal layer, and an adhesive layer 7 is provided between the first blank area 51 and the battery body.

[0065] In this way, when the battery is a double-folded battery, the side seal 5 is folded twice and bonded to the battery body, and a first blank area 51 is provided on the surface of the first edge close to the battery body. The exposed metal layer of the first blank area 51 and the battery body are more firmly bonded, which can effectively improve the fixing strength of the first edge of the side seal 5 and the battery body.

[0066] like Fig.10 As shown, in a preferred embodiment, the side edge seal includes a bent portion between the first edge portion and the second edge portion, and the end of the first blank area does not exceed the bent portion.

[0067] exist Fig.10 The connection between the first side and the second side, that is, the bent portion, is exposed to the outside, so the insulation performance of this part also needs to be guaranteed. Therefore, the end of the first blank area does not exceed the bent portion to allow a part of the protective layer 11 to be retained on the upper end of the first side.

[0068] In a preferred embodiment, the adhesive layer covers the end surface of the side seal, so that the open end of the second edge can be bonded to the first edge and to the battery body without being easily spread out, so that the width of the battery will not be too large.

[0069] like Fig.10 As shown, in a preferred embodiment, a second blank area 52 is further provided on the surface opposite to the first side portion and the second side portion, the protective layer 11 at the second blank area 52 is removed, and an adhesive layer 7 is provided on the second blank area 52 .

[0070] In order to further ensure the bonding effect between the second edge and the edge of the battery body, a second blank area 52 is set on one side of the second edge, so that an adhesive layer 7 is set between the first edge and the second edge, and the adhesive layer 7 can better fix the first edge and the second edge firmly.

[0071] like Fig.10 As shown, in a preferred embodiment, the side seal includes a bending portion between the first edge portion and the second edge portion, and the end of the second blank area does not exceed the bending portion to avoid loss of the protective layer at the bending portion resulting in damage to the insulation performance.

[0072] like Fig.10 As shown, in a preferred embodiment, the width of the second blank area 52 is greater than the width of the first blank area 51 .

[0073] Since the second blank area 52 is arranged on the surface opposite to the first side portion and the second side portion, that is, the second blank area 52 is arranged on both opposite surfaces, the width of the second blank area 52 can be set to twice that of the first blank area 51, so that the first side portion and the second side portion can be adhered more firmly.

[0074] In a preferred embodiment, since the first blank area 51 or the second blank area 52 provided on the side seal has an exposed metal layer, its adhesion is better, and the adhesive layer is in contact with the protective layer on one side of the battery body. Therefore, the bonding force between the battery body and the adhesive layer is smaller than the bonding force between the adhesive layer and the side seal.

[0075] Specifically, the bonding force between the battery body and the adhesive layer is F1, and the value of F1 satisfies: F1 ≥ 0.5 N / mm; the bonding force between the adhesive layer and the side sealing edge is F2, and the value of F2 satisfies: F2 ≥ 1 N / mm.

[0076] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0077] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0078] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed or recombined, and these decompositions or recombinations should be regarded as equivalent solutions of the present application.

[0079] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0080] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0081] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A battery, characterized in that: It includes a battery cell, a shell, and a tab on the battery cell; The shell wraps the battery core to form a battery body; The shell comprises a protective layer, a metal layer and an insulating layer which are stacked in sequence; The shell comprises a first shell layer and a second shell layer, wherein the first shell layer and the second shell layer are attached to form a side seal located on at least one side of the battery body and a top seal located on one side of the tab; The side seal includes a first edge portion folded toward the battery body, the protective layer on the side of the first edge portion close to the battery body forms a first blank area exposing the metal layer, and an adhesive layer is arranged between the first blank area and the battery body.

2. The battery according to claim 1, characterized in that One end of the first blank area in the first direction at least extends to the edge of the top seal on the side of the side seal, and the other end of the first blank area in the first direction is flush with the edge of the side seal in the first direction.

3. The battery according to claim 1, characterized in that The first blank area is arranged along the first direction of the side edge seal, and a size of the first blank area in the second direction is smaller than a size of the side edge seal in the second direction.

4. The battery according to claim 3, characterized in that The side seal includes a bent portion located between the battery body and the first edge portion; An end of the first blank area close to the battery body does not exceed the bent portion.

5. The battery according to claim 3, characterized in that The size of the first blank area in the second direction is W1, the size of the side edge seal in the second direction is W2, and the relationship between W1 and W2 satisfies W1:W2≥60%; and / or, The area of ​​the first blank area is S1, the area of ​​the side edge seal is S2, and the relationship between S1 and S2 satisfies S1:S2≥60%.

6. The battery according to claim 1, characterized in that An insulating adhesive layer is arranged at the outer edge of the side edge seal in the second direction, and the insulating adhesive layer completely covers the cross section of the outer edge of the side edge seal.

7. The battery according to claim 6, characterized in that The insulating adhesive layer and the first blank area at least partially overlap.

8. The battery according to claim 1, characterized in that The side sealing edge includes a second edge portion connecting the first edge portion and the battery body, and the second edge portion is located on a side of the first edge portion away from the battery body.

9. The battery according to claim 7, characterized in that The adhesive layer covers the end surface of the side edge seal.

10. The battery according to claim 8, characterized in that A second blank area exposing the metal layer is also provided on the surface of the second side portion close to the battery body, and the adhesive layer is provided on the second blank area.

11. The battery according to claim 10, characterized in that The side edge seal includes a bent portion between the first edge portion and the second edge portion, and an end portion of the second blank area does not exceed the bent portion.

12. The battery according to claim 1, characterized in that The bonding force between the battery body and the adhesive layer is smaller than the bonding force between the adhesive layer and the side sealing edge.

13. The battery according to claim 12, characterized in that The bonding force between the battery body and the adhesive layer is F1, and the value of F1 satisfies: F1 ≥ 0.5 N / mm; and / or, The bonding force between the adhesive layer and the side edge seal is F2, and the value of F2 satisfies: F2 ≥ 1 N / mm.

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