CN219476918U - Diaphragm and battery cell - Google Patents

Abstract

The application relates to a diaphragm and electric core, it includes: a separator body comprising a plurality of repeating units, each repeating unit having a length equal to a length of the separator body used to wind into a single winding core; one surface of each repeating unit in the thickness direction is provided with a tail-end connecting piece; the ending connecting piece comprises an anti-sticking isolation part and an adhesive part; the adhesive portion is provided on one of the surfaces in the thickness direction of the repeating unit, and the anti-sticking spacer is laid on the surface of the adhesive portion remote from the repeating unit. When the winding core is finished and then is finished, the anti-sticking isolation part of the finishing connecting piece is torn off, the tail part of the repeating unit is bonded to the surface of the coiled repeating unit through the bonding part, and the diaphragm with the structure does not need hot pressing and pasting in the winding core and final finishing process, so that indentation is prevented from occurring at a negative electrode interface, and the integrity of an electric core interface is prevented from being damaged.

Description

Diaphragm and battery cell

Technical Field

The application relates to the technical field of batteries, in particular to a diaphragm and an electric core.

Background

The battery cell formed by winding the positive plate, the negative plate and the diaphragm is called a winding core.

In some related arts, the structure of the cross section of the winding core is shown in fig. 1, in which a separator body 1 separates and tightens a positive electrode sheet 2 and a negative electrode sheet 3, and the tail of the separator is end-to-end bonded by a blue adhesive 4 after winding is completed; the state in which the blue gel 4 is stuck on the winding core is shown in fig. 2, and the blue gel 4 connects the tail part (mark a) of the separator and the already wound part (i.e., the part corresponding to the cover on the negative electrode sheet 3, mark B) of the separator; but it has the following problems:

(1) After the blue gel is required to be cut, the blue gel is posted through hot pressing so as to be bonded with the marks A and B at the same time, ending bonding can be realized, and the blue gel 4 can be provided with an indentation at a negative electrode interface when the blue gel is fully charged through hot pressing, so that the integrity of an electric core interface is easily damaged, and the performance of a battery is influenced.

(2) The cost of the blue adhesive is higher, the blue adhesive needs to be cut by an additional mechanism, and when the blue adhesive is posted, the degree of tightness of the blue adhesive is different due to the influence of errors of the posting mechanism, so that the consistency of the state of the battery cell is poor.

Disclosure of Invention

The embodiment of the application provides a diaphragm and a battery cell, which are used for solving the problem that the integrity and consistency of a battery cell interface are affected by sticking blue glue for ending in the related technology.

In a first aspect, there is provided a separator comprising:

a separator body comprising a plurality of repeating units, each of the repeating units having a length equal to a length of the separator body used to wind into a single winding core; one surface of each repeating unit in the thickness direction is provided with a tail-end connecting piece;

wherein the ending connection is configured to:

the ending connector comprises an anti-sticking isolation part and an adhesive part; the adhesive portion is provided on one of the surfaces in the thickness direction of the repeating unit, and the anti-sticking spacer is laid on the surface of the adhesive portion remote from the repeating unit.

In some embodiments, the ending connectors on each of the repeating units are disposed at one end of the repeating unit along the length of the diaphragm body.

In some embodiments, each ending connector has a first projection in a thickness direction of the repeating unit and the repeating unit corresponding to the ending connector has a second projection in a thickness direction thereof, the second projection completely covering the first projection; and each repeating unit takes one end of the ending connecting piece as a starting end, along the length direction of the diaphragm body, the first projection sequentially comprises a first side edge and a second side edge which extend along the width direction of the diaphragm body, and the second projection sequentially comprises a third side edge and a fourth side edge which extend along the width direction of the diaphragm body;

the first side edge and the third side edge are completely overlapped, or a set distance is arranged between the first side edge and the third side edge.

In some embodiments, the length of each ending link is equal to the width of the repeating unit corresponding to that ending link in the width direction of the repeating unit.

In some embodiments, the release barrier has a third projection in the thickness direction of the repeating unit and the adhesive has a fourth projection in the thickness direction of the repeating unit, the third projection completely covering the fourth projection.

In some embodiments, a tear portion is disposed on a side of the anti-adhesion spacer, the tear portion extends from a side of the anti-adhesion spacer along a width direction of the separator body, and the tear portion and the anti-adhesion spacer are integrally formed.

In some embodiments, the ending connector is a double-sided adhesive tape with a double-sided adhesive tape, the corresponding adhesive portion is a back adhesive portion of the double-sided adhesive tape, and the corresponding anti-sticking isolation portion is release paper of the double-sided adhesive tape.

In some embodiments, a groove is provided on each repeating unit at a location corresponding to the ending connection; the bonding part of the ending connecting piece is a glue layer accommodated in the groove; the anti-sticking isolation part covers the groove.

In some embodiments, the anti-sticking isolation part adopts a hot melt cover, the bonding part adopts a glue layer, and the hot melt cover covers the glue layer.

In a second aspect, there is provided a cell comprising:

diaphragm, and the roll core that positive plate, negative plate, anodal utmost point ear and negative plate ear formed.

The beneficial effects that technical scheme that this application provided brought include:

the embodiment of the application provides a diaphragm and electric core, because the diaphragm body includes a plurality of repeating units, repeating units are used for cooperating positive and negative pole piece to wind into a roll core, when the roll core is accomplished the back and is carried out the ending, tear the antiseized isolation part of ending connecting piece, tail and the bonding of repeating units are at the surface of the repeating units that has already been convoluteed through the bonding part, use the diaphragm of this structure at the roll core of coiling and final ending in-process, need not hot pressing to post, avoid appearing the indentation at the negative pole interface, destroy electric core interface integrality, in addition on the bonding part is located the repeating units, post along with the coiling operation, the ending operation is also accomplished to the bonding part after the coiling is accomplished promptly, thereby guarantee the elasticity degree of bonding part unanimous.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic cross-sectional view of a related art winding core;

FIG. 2 is a schematic perspective view of a winding core in the related art;

FIG. 3 is a schematic view of a separator provided in an embodiment of the present application;

FIG. 4 is a schematic cross-sectional view of a winding core provided in an embodiment of the present application;

fig. 5 is a schematic cross-sectional view of another embodiment of the present application in which a final connector is provided on the diaphragm body.

In the figure: 1. a diaphragm body; 2. a positive plate; 21. a positive electrode tab; 3. a negative electrode sheet; 31. a negative electrode tab; 4. blue glue; 5. and (5) ending the connecting piece.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

The related art winding core structure as shown in fig. 1 and 2, in which blue glue 4 is located on the outer surface of the outermost separator of the winding core and is simultaneously bonded to the areas marked a and B, is completed.

But blue glue 4 needs an extra mechanism to cut and then post; the posting operation is completed by hot pressing across the areas of mark a and mark B. In the process, indentation can be formed on the surface of the negative electrode plate when the battery is fully charged by hot pressing, so that the integrity of an interface of the battery cell is easily damaged, and the performance of the battery is influenced; in addition, the tightness degree of the blue adhesive 4 is different, so that the consistency of the state of the battery cell is poor; in addition, the cost of the blue gel 4 is also high.

Therefore, based on the above situation, the present application provides a membrane and a battery cell, so as to solve the problem that the integrity and consistency of the interface of the battery cell are affected by sticking blue gel in the related art.

Referring to fig. 3, a diaphragm includes a diaphragm body 1, the diaphragm body 1 includes a plurality of repeating units, a length of each repeating unit (a dimension of the repeating unit along a length direction in fig. 3, that is, a length of the repeating unit) is equal to a length of the diaphragm body 1 used for winding into a single winding core, one surface of the repeating unit in a thickness direction is provided with a tail connector 5, the tail connector 5 includes an anti-adhesion isolation portion and an adhesion portion, the adhesion portion is disposed on one surface of the repeating unit in the thickness direction, and the anti-adhesion isolation portion is laid on a surface of the adhesion portion away from the repeating unit and can be detached and torn off.

Further, along the length of the diaphragm body 1 (i.e. the length as illustrated in fig. 3), the ending connectors 5 on each of the repeating units are provided at one end of the repeating unit.

In the process of forming a winding core by matching the positive plate 2, the negative plate 3, the positive tab 21 and the negative tab 31, cutting the diaphragm body 1 based on one repeating unit; then, during winding, the end, where the repeating unit is not provided with the ending connector 5, is taken as a winding starting end, then the anti-sticking isolation part of the ending connector 5 can be torn off during ending, and then the tail part of the repeating unit is adhered to the repeating unit of the secondary inner layer by using the adhesive part, so that ending operation is completed.

By using the diaphragm, hot pressing and pasting are not needed in the winding core and final ending process, so that the occurrence of indentation on the negative electrode plate is avoided, and the integrity of the interface of the battery cell is damaged.

In addition, referring to fig. 4, two repeating units are actually disposed in each winding core, so that at the ending position of the winding core, the tail part of each repeating unit is provided with an ending connector 5, after the anti-sticking isolation part is torn off, the diaphragm continues to wind, and the diaphragm is bonded with the pole piece and the diaphragm through the bonding part at the same time of finishing winding. The end closing operation of the bonding part is also completed after the winding is finished, so that the consistency of the tightness of the bonding part is ensured.

In addition, the adoption of the ending connecting piece 5 does not need to adopt an additional mechanism to cut the blue film, so that the ending operation steps are simplified.

In some preferred embodiments, the setting position (setting position may be selected as first setting position or second setting position as follows) and the size of the ending connection 5 on each repeating unit have the following requirements:

each ending connector 5 has a first projection in the thickness direction of the repeating unit, and the repeating unit corresponding to that ending connector 5 has a second projection in its thickness direction, said second projection completely covering said first projection; and each repeating unit takes one end where the ending connecting piece 5 is located as a starting end, along the length direction of the diaphragm body 1, the first projection sequentially has a first side and a second side extending along the width direction of the diaphragm body 1, and the second projection sequentially has a third side and a fourth side extending along the width direction of the diaphragm body 1.

And the first side edge and the third side edge are completely overlapped at the first setting position. As shown in fig. 4, the joint between the ending connector 5 and the ending part is equal after the winding is completed, and no flanging or edge warping exists.

Second setting position: a set distance is arranged between the first side edge and the third side edge; the setting position can also realize ending operation, and only the part of the repeating unit reserved with a set distance after finishing is not bonded. The specific value of the set distance may be selected according to actual needs.

Further, in order to improve the bonding effect of the ending, the tail of the diaphragm has no edge warping, and there is a certain requirement on the size area of the ending connector 5 on each repeating unit, so the following can be set: in the width direction of the repeating unit (as shown in fig. 3), the length of the ending connector 5 (as shown in reference E of fig. 3) is equal to the width of the repeating unit;

further, it may be configured that: the ending-connection 5 may be divided in the width direction of the repeating unit into two equal parts symmetrically arranged about the centre line of the repeating unit, which is marked C in fig. 3. This is to avoid the positional shift of the bonding at the time of ending.

Further, in order to prevent the membrane body 1 from sticking to the finishing connector 5 and the repeating unit at the time of winding before finishing, it is necessary to set the area of the anti-sticking spacer to: the area of the anti-sticking isolation part is larger than or equal to that of the bonding part, the anti-sticking isolation part is provided with a third projection in the thickness direction of the repeating unit, the bonding part is provided with a fourth projection in the thickness direction of the repeating unit, and the third projection completely covers the fourth projection, so that the anti-sticking isolation part completely covers the bonding part. On the basis of the above, when the ending operation is conveniently carried out, the anti-sticking isolation part is torn off, a tearing part is arranged on one side edge of the anti-sticking isolation part, and extends from one side edge of the anti-sticking isolation part along the width direction (shown in fig. 3) of the diaphragm body 1, so that the extending end of the tearing part exceeds the anti-sticking isolation part, and the anti-sticking isolation part is torn off when the ending operation is convenient in the later period. And the tearing part and the anti-sticking isolation part are integrally formed.

In some preferred embodiments, the ending connector 5 is a double-sided adhesive tape with double-sided adhesive tape, the corresponding adhesive portion is the adhesive-backed portion of the double-sided adhesive tape, and the corresponding anti-sticking isolation portion is release paper of the double-sided adhesive tape; of course, the adhesive part of the ending connector 5 can also be a glue layer, and the anti-sticking isolation part is an anti-sticking film. The back adhesive part and the glue coating of the double-sided adhesive tape adopt hot melt adhesives, and can also be other glues. The materials of the release barrier portion and the adhesive portion need not react with the electrolyte and should be insoluble in the electrolyte.

In some preferred embodiments, referring to fig. 5, a groove is provided on each repeating unit at a position corresponding to the ending connection 5. The contour of the projection of the groove in the thickness direction of the repeating unit is a round hole or a T shape. The bonding part of the ending connecting piece 5 is a glue layer accommodated in the groove; the anti-sticking isolation part covers the groove. The glue layer is made of glue.

When ending, tear antiseized isolation part, glue is extruded in the winding process to bond between diaphragm and the diaphragm, such structure not only plays the effect of connection, has also reduced the use of glue.

In some preferred embodiments, the release barrier uses a hot melt cover, the adhesive uses a layer of glue, and the hot melt cover covers the layer of glue.

The application also provides a battery cell, which comprises:

the repeating unit described above, and the battery cell formed of the positive electrode tab 2, the negative electrode tab 3, the positive electrode tab 21, and the negative electrode tab 31. And (3) preparing the battery cell according to the battery cell preparation procedure.

The present application also proposes a battery, which includes: the battery cell. The battery manufactured by adopting the structure can ensure the consistency and the integrity of the battery core, and reduces the production cost.

In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of description of the present application and simplification of the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

It should be noted that in this application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A separator, comprising:

a separator body (1) comprising a plurality of repeating units, each of which has a length equal to the length of the separator body (1) used for winding into a single winding core; one surface of each repeating unit in the thickness direction is provided with a tail-in connecting piece (5);

wherein the ending connection (5) is configured to:

the ending connector (5) comprises an anti-sticking isolation part and an adhesive part; the adhesive portion is provided on one of the surfaces in the thickness direction of the repeating unit, and the anti-sticking spacer is laid on the surface of the adhesive portion remote from the repeating unit.

2. The diaphragm of claim 1, wherein:

along the length direction of the diaphragm body (1), the ending connector (5) on each repeating unit is arranged at one end of the repeating unit.

3. The diaphragm of claim 1, wherein:

each ending connector (5) has a first projection in the thickness direction of the repeating unit, and the repeating unit corresponding to the ending connector (5) has a second projection in the thickness direction thereof, the second projection completely covering the first projection; and each repeating unit takes one end of the ending connecting piece (5) as a starting end, and along the length direction of the diaphragm body (1), the first projection sequentially comprises a first side edge and a second side edge which extend along the width direction of the diaphragm body (1), and the second projection sequentially comprises a third side edge and a fourth side edge which extend along the width direction of the diaphragm body (1);

the first side edge and the third side edge are completely overlapped, or a set distance is arranged between the first side edge and the third side edge.

4. The diaphragm of claim 1, wherein:

in the width direction of the repeating unit, the length of each ending connection (5) is equal to the width of the repeating unit corresponding to the ending connection (5).

5. The diaphragm of claim 4, wherein:

the anti-sticking isolation part has a third projection in the thickness direction of the repeating unit, the bonding part has a fourth projection in the thickness direction of the repeating unit, and the third projection completely covers the fourth projection.

6. The diaphragm of claim 1, wherein:

the anti-sticking isolation part comprises a diaphragm body (1), wherein a tearing part is arranged on one side edge of the anti-sticking isolation part, extends from one side edge of the anti-sticking isolation part along the width direction of the diaphragm body, and is integrally formed with the anti-sticking isolation part.

7. The diaphragm of claim 6, wherein:

the ending connecting piece (5) is a double-sided adhesive tape with double-sided adhesive tapes, the corresponding adhesive part is the adhesive-backed part of the double-sided adhesive tapes, and the corresponding anti-sticking isolation part is release paper of the double-sided adhesive tapes.

8. The diaphragm of claim 1, wherein:

grooves are arranged at positions of each repeating unit corresponding to the ending connecting pieces (5); the bonding part of the ending connecting piece (5) is a glue layer accommodated in the groove; the anti-sticking isolation part covers the groove.

9. The diaphragm of claim 1, wherein:

the anti-sticking isolation part adopts a hot melt cover, the bonding part adopts a glue layer, and the hot melt cover covers the glue layer.

10. A cell, comprising:

the separator according to any one of claims 1 to 9, and a winding core formed of a positive electrode sheet (2), a negative electrode sheet (3), a positive electrode tab (21), and a negative electrode tab (31).