阅读说明：本技术 叠片电芯及其断面封装方法 (Laminated battery cell and section packaging method thereof ) 是由 游悠 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种叠片电芯及其断面封装方法。本发明中,叠片电芯包括：多个极片、一连续的带状的隔膜,隔膜呈Z字型间隔在各相邻的两极片之间、以及覆盖在最外层的极片的外表面,各相邻的两极片极性相反；夹持同一极片的隔膜的两部分形成弯折相连的一对隔膜层,一对隔膜层弯折相连的部分所在侧为叠片电芯的断面侧；断面封装方法包括如下步骤：将隔膜热熔让至少一个断面侧中各隔膜层的端面相连形成封装面。与现有技术相比,使得避免电池生产过程中正负极极片错位,提高电池良品率和安全性能。(The invention discloses a laminated battery cell and a section packaging method thereof. In the present invention, a laminated cell includes: the diaphragm is arranged between every two adjacent pole pieces in a Z shape at intervals and covers the outer surface of the outermost pole piece, and the polarities of every two adjacent pole pieces are opposite; two parts of the diaphragm clamping the same pole piece form a pair of diaphragm layers which are connected in a bending way, and the side where the parts connected in a bending way of the pair of diaphragm layers are located is the section side of the laminated cell; the section packaging method comprises the following steps: and thermally fusing the diaphragm to connect the end surfaces of the diaphragm layers in at least one section side to form a packaging surface. Compared with the prior art, the positive and negative pole pieces are prevented from being dislocated in the production process of the battery, and the yield and the safety performance of the battery are improved.)

1. A section packaging method of a laminated battery cell is characterized in that the laminated battery cell comprises a plurality of pole pieces and a continuous strip-shaped diaphragm, the diaphragm is arranged between every two adjacent pole pieces in a Z-shaped interval and covers the outer surface of the outermost pole piece, the polarities of every two adjacent pole pieces are opposite, two parts of the diaphragm clamping the same pole piece form a pair of diaphragm layers which are connected in a bending mode, the side where the parts connected in the bending mode of the pair of diaphragm layers are located is the section side of the laminated battery cell,

the section packaging method comprises the following steps:

and thermally fusing the diaphragm so that the end faces of the diaphragm layers in at least one section side are connected to form a packaging surface.

2. The method of claim 1, wherein the step of heat-fusing the membranes to connect the end surfaces of the membrane layers in at least one of the cross-sectional sides to form a package surface comprises: and thermally fusing the end surfaces of the membrane layers on the section side to the adjacent two membrane layers for connection.

3. The method of claim 1, further comprising: before the diaphragm is hot-melted, the parts of the pair of diaphragm layers which are connected in a bending mode are pushed to be flat towards the direction of the pole piece.

4. The method of claim 3, wherein the step of flattening the folded and connected portions of the pair of separator layers toward the pole pieces comprises: and pushing the bent and connected parts of the pair of membrane layers to be flat so that the pair of membrane layers are in contact with the adjacent membrane layers.

5. The method of claim 1, further comprising: and after the diaphragm is subjected to hot melting, punching holes on the packaging surface to form liquid through holes.

6. The method of claim 1, wherein the step of heat-fusing the membranes to connect the end surfaces of the membrane layers in at least one of the cross-sectional sides to form a package surface comprises: and thermally fusing the diaphragms to respectively connect the end surfaces of the diaphragm layers in the pair of cross-sectional sides to form a pair of package surfaces.

7. The method of claim 1, wherein at least one side of the separator layer adjacent to the pole piece is coated with an adhesive layer, and the adhesive layer is located in a partial region of the separator layer.

8. The method of claim 7, wherein the adhesive layer has two portions, and the two portions are respectively coated on two ends of the separator layer facing the tabs of the pole pieces.

9. The method of claim 7, wherein the adhesive layer has a plurality of strip portions arranged at intervals, and each strip portion is inclined to the length direction of the pole piece.

10. A laminated cell, comprising:

a plurality of pole pieces; and

a continuous strip diaphragm, the diaphragm is arranged between each two adjacent pole pieces in a Z shape at intervals and covers the outer surface of the outermost pole piece, the polarities of each two adjacent pole pieces are opposite, two parts of the diaphragm clamping the same pole piece form a pair of diaphragm layers which are connected in a bending way, the side where the bent and connected parts of the pair of diaphragm layers are located is the section side of the laminated cell,

wherein the end faces of the membrane layers in at least one of the cross-sectional sides are thermally fused to form an encapsulation surface.

11. The laminated cell of claim 10, wherein the sealing surface is provided with a fluid hole.

Technical Field

The invention relates to the technical field of batteries, in particular to a laminated battery cell and a section packaging method thereof.

Background

With the development of power battery technology, the soft package battery is more and more widely applied due to the advantages of good safety performance, light weight, large capacity, small internal resistance, flexible design and the like. The existing soft package lithium ion battery generally adopts a Z-shaped laminated battery cell, wherein positive and negative pole pieces of the battery cell are easy to dislocate in the production process of the battery, so that the lithium ion battery is low in voltage and short-circuited, and the safety performance of the battery is poor.

Disclosure of Invention

The invention aims to provide a laminated battery cell and a section packaging method thereof, so that dislocation of positive and negative pole pieces in the production process of the battery is avoided, and the yield and the safety performance of the battery are improved.

In order to solve the above technical problems, an embodiment of the present invention provides a method for encapsulating a cross section of a laminated battery cell, where the laminated battery cell includes a plurality of pole pieces and a continuous strip-shaped diaphragm, the diaphragm is spaced between each two adjacent pole pieces in a zigzag manner and covers the outer surface of the outermost pole piece, the two adjacent pole pieces have opposite polarities, two portions of the diaphragm sandwiching the same pole piece form a pair of diaphragm layers connected by bending, and the side of the bent connected portion of the pair of diaphragm layers is the cross section side of the laminated battery cell,

the section packaging method comprises the following steps:

and thermally fusing the diaphragm so that the end faces of the diaphragm layers in at least one section side are connected to form a packaging surface.

In one embodiment, heat-fusing the separator so that end faces of the respective separator layers in at least one of the cross-sectional sides are joined to form an encapsulation face includes: and thermally fusing the end surfaces of the membrane layers on the section side to the adjacent two membrane layers for connection.

In an embodiment, the method for encapsulating the section of the laminated cell further includes: before the diaphragm is hot-melted, the parts of the pair of diaphragm layers which are connected in a bending mode are pushed to be flat towards the direction of the pole piece.

In one embodiment, flattening the portion of the pair of membrane layers that is joined by a fold toward the direction of the pole piece comprises: and pushing the bent and connected parts of the pair of membrane layers to be flat so that the pair of membrane layers are in contact with the adjacent membrane layers.

In an embodiment, the method for encapsulating the section of the laminated cell further includes: and after the diaphragm is subjected to hot melting, punching holes on the packaging surface to form liquid through holes.

In one embodiment, heat-fusing the separator so that end faces of the respective separator layers in at least one of the cross-sectional sides are joined to form an encapsulation face includes: and thermally fusing the diaphragms to respectively connect the end surfaces of the diaphragm layers in the pair of cross-sectional sides to form a pair of package surfaces.

In one embodiment, at least one side of the diaphragm layer adjacent to the pole piece is coated with an adhesive layer, and the adhesive layer is located in a partial area of the diaphragm layer.

In one embodiment, the adhesive layer has two portions, and the two portions are respectively coated on two ends of the separator layer facing the tabs of the pole pieces.

In one embodiment, the adhesive layer has a plurality of strip portions arranged at intervals, and each strip portion is inclined with the length direction of the pole piece.

An embodiment of the present invention further provides a laminated battery cell, including:

a plurality of pole pieces; and

a continuous strip diaphragm, the diaphragm is arranged between each two adjacent pole pieces in a Z shape at intervals and covers the outer surface of the outermost pole piece, the polarities of each two adjacent pole pieces are opposite, two parts of the diaphragm clamping the same pole piece form a pair of diaphragm layers which are connected in a bending way, the side where the bent and connected parts of the pair of diaphragm layers are located is the section side of the laminated cell,

wherein the end faces of the membrane layers in at least one of the cross-sectional sides are thermally fused to form an encapsulation surface.

In one embodiment, the packaging surface is provided with a liquid through hole.

Compared with the prior art, the end faces of the diaphragm layers positioned on the fracture surface side are connected through the diaphragm hot melting to form the packaging surface, so that the fracture surface side is packaged, the moving space of the pole piece between the two diaphragm layers is reduced, the pole piece is positioned, the pole piece dislocation risk in the battery preparation process is reduced, the battery is subjected to low voltage or short circuit, and the yield and the safety performance of the battery are improved.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a cross-sectional side unencapsulated cross-sectional view of a laminated cell in accordance with some embodiments of the invention;

fig. 2 is a cross-sectional view of a laminated cell after cross-sectional side encapsulation in accordance with some embodiments of the invention;

fig. 3 is a schematic structural diagram of a laminated cell according to some embodiments of the invention;

FIG. 4 is a schematic diagram of a two-part adhesive layer according to some embodiments of the present invention;

FIG. 5 is a schematic view of a portion of an embodiment of an adhesive layer in the form of a strip;

fig. 6 is a flow chart of a cross-section packaging method according to some embodiments of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

In the following description, for the purposes of illustrating various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be understood as an open, inclusive meaning, i.e., as being interpreted to mean "including, but not limited to," unless the context requires otherwise.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings in order to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the spirit of the technical solution of the present invention.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise.

In the following description, for the purposes of clearly illustrating the structure and operation of the present invention, directional terms will be used, but terms such as "front", "rear", "left", "right", "outer", "inner", "outer", "inward", "upper", "lower", etc. should be construed as words of convenience and should not be construed as limiting terms.

Embodiments of the present invention are described below with reference to the drawings.

The first embodiment of the invention relates to a section packaging method of a laminated battery cell. As shown in fig. 1 and 2, the laminated cell 200 is a portion of a battery, and the laminated cell 200 includes: a plurality of pole pieces 1, a continuous strip-shaped diaphragm. The separator is arranged between the two adjacent pole pieces 1 in a Z-shaped interval and covers the outer surface of the outermost pole piece 1. The two adjacent pole pieces 1 have opposite polarities. Two parts of the diaphragm clamping the same pole piece 1 form a pair of diaphragm layers 2 which are connected in a bending way, and the side of the part, connected in a bending way, of the pair of diaphragm layers 2 is the section side of the laminated battery cell 200, and the laminated battery cell 200 has section sides 3 and 4 in the figure.

As shown in fig. 1, 2 and 6, the cross-section packaging method includes: at step 110, the membrane is thermally fused to connect the end surfaces of the membrane layers 2 on the pair of cross-sectional sides, respectively, to form a pair of package surfaces. That is, the end faces of the respective diaphragm layers 2 located on the cross-sectional side 3 are connected to form a sealing face 5, and the end faces of the respective diaphragm layers 2 located on the cross-sectional side 4 are connected to form a sealing face 6.

In another example, the end faces of the respective membrane layers 2 on one cross-sectional side may be connected to form a sealing face, and the other cross-sectional side may be formed without a sealing face. I.e. the membrane is heat fused to join the end faces of the membrane layers 2 in at least one cross-sectional side to form a package face.

Through the content, the end faces of the diaphragm layers 2 on the side of the fracture surface are connected to form the packaging surface through hot melting of the diaphragms, so that the side of the fracture surface is packaged, the moving space of the pole piece 1 between the two diaphragm layers 2 is reduced, the pole piece 1 is positioned, the risk of dislocation of the pole piece 1 in the battery preparation process is reduced, the battery is low-voltage or short-circuited, and the yield and the safety performance of the battery are improved.

The following describes the implementation details of the section packaging method of the present embodiment in detail, and the following is only provided for the convenience of understanding and is not necessary to implement the present embodiment.

Further, step 110 specifically includes the following steps: the end faces of the separator layers 2 on the cross-sectional side are thermally fused to the adjacent two separator layers 2. I.e., heat staking the end faces circled at a and B in fig. 1 to form package faces 5 and 6 in fig. 2.

It will be appreciated that in other embodiments, other portions of the diaphragm may be heat fused to the profile side to form the package face. If each layer of the membrane layer 2 is laid longer, the membrane layer 2 extending out of the pole piece 1 is connected with the membrane on the section side through hot melting. In other embodiments, the bottom or top membrane layer 2 may be laid longer and then folded to seal the cross-section side and then heat fused to join the membrane layers 2 of each layer.

Further, as shown in fig. 6, before step 110, the method for encapsulating a fracture surface further includes: step 120, pushing the bent and connected portions of the pair of separator layers 2 flat toward the direction of the pole piece 1.

Specifically, as shown in fig. 1 and 2, the portion 51 of the diaphragm layer 2 on the cross-sectional side 3 that is bent and connected is pushed flat in the direction of arrow C, and the portion 61 of the diaphragm layer 2 on the cross-sectional side 4 that is bent and connected is pushed flat in the direction of arrow D. The bent and connected part of the diaphragm layer 2 is a convex arc surface which is far away from the adjacent diaphragm layer 2. After the bending and connecting part of the membrane layer 2 is pushed flat, the bending and connecting part of the membrane layer 2 can be close to other adjacent membrane layers 2, so that a packaging surface is formed conveniently. The term "flattening" is to be understood as "pushing the circular arc surface to a vertical plane", and as "reducing the arc of the circular arc surface" or "changing the convex circular arc surface to another shape" as long as the bent portion of the diaphragm layer 2 is close to the other diaphragm layer 2.

Preferably, after the bent and connected portions of the pair of membrane layers 2 are flattened, the pair of membrane layers 2 are in contact with the adjacent membrane layers 2, so that the end faces of the connected membrane layers 2 are conveniently connected during hot melting, and a packaging surface is conveniently formed.

In addition, as shown in fig. 3 and fig. 6, after step 110, the method for encapsulating a cross section further includes: and step 130, punching holes on the packaging surface to form liquid through holes 8.

In this embodiment, both the sealing surfaces 5 and 6 are perforated, so that after the laminated battery cell 200 is soaked in electrolyte, the electrolyte can more easily enter the space between the two layers of diaphragms to contact the pole piece 1, thereby improving the soaking effect of the battery cell, shortening the soaking time of the battery cell and improving the production efficiency. In other embodiments, only one of the package faces may be perforated.

Further, as shown in fig. 4 and 5, at least one side of the membrane layer 2 adjacent to the pole piece 1 is coated with an adhesive layer 7, and the adhesive layer 7 is located in a partial area of the membrane layer 2. The pole piece 1 is further positioned between the two separator layers 2, preventing the pole piece 1 from being dislocated. Compared with the adhesive layer 7 which is coated on the surface of the diaphragm layer 2 in a comprehensive mode, the battery core has better infiltration effect and lower cost.

Alternatively, as shown in fig. 4, the adhesive layer 7 has two portions, and the two ends of the separator layer 2 facing the tabs 10 of the pole piece 1 are respectively coated, that is, adjacent to a pair of tabs 10 respectively.

Alternatively, as shown in fig. 5, the adhesive layer 7 has a plurality of strip portions arranged at intervals, and each strip portion is inclined with respect to the length direction of the pole piece 1.

Furthermore, the two sides of the diaphragm layer 2 connected with the pole piece 1 are coated with adhesive layers 7.

The steps of the above methods are divided for clarity, and the implementation may be combined into one step or split some steps, and the steps are divided into multiple steps, so long as the same logical relationship is included, which are all within the protection scope of the present patent; it is within the scope of the patent to add insignificant modifications to the algorithms or processes or to introduce insignificant design changes to the core design without changing the algorithms or processes.

A second embodiment of the invention relates to a laminated cell 200. As shown in fig. 2 and 3, the laminated cell 200 includes: a plurality of pole pieces 1, a continuous strip-shaped diaphragm. The separator is arranged between the two adjacent pole pieces 1 in a Z-shaped interval and covers the outer surface of the outermost pole piece 1. The two adjacent pole pieces 1 have opposite polarities. Two parts of the diaphragm clamping the same pole piece 1 form a pair of diaphragm layers 2 which are connected in a bending way, and the side of the part, connected in a bending way, of the pair of diaphragm layers 2 is the section side of the laminated battery core 200. Wherein the end faces of the respective membrane layers 2 in at least one cross-sectional side are thermally fused to form a package face. Preferably, the end faces of the respective membrane layers 2 of the two cross-sectional sides 3 and 4 are thermally fused together to form the package faces 5 and 6, respectively.

Further, as shown in fig. 2 and 3, the package surfaces 5 and 6 are both provided with liquid through holes 8. In other embodiments, one of the sealing surfaces 5 and 6 may be provided with a liquid through hole 8.

Since the first embodiment corresponds to the present embodiment, the present embodiment can be implemented in cooperation with the first embodiment. The related technical details mentioned in the first embodiment are still valid in this embodiment, and the technical effects that can be achieved in the first embodiment can also be achieved in this embodiment, and are not described herein again in order to reduce the repetition. Accordingly, the related-art details mentioned in the present embodiment can also be applied to the first embodiment.

While the preferred embodiments of the present invention have been described in detail above, it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above detailed description. In general, in the claims, the terms used should not be construed to be limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.