CN218887449U

CN218887449U - Diaphragm structure and battery

Info

Publication number: CN218887449U
Application number: CN202223336530.2U
Authority: CN
Inventors: 王守兵; 崔亚锋
Original assignee: Svolt Energy Technology Co Ltd
Current assignee: Svolt Energy Technology Co Ltd
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2023-04-18
Anticipated expiration: 2032-12-13

Abstract

The utility model relates to a battery technology field, concretely relates to diaphragm structure and battery. The utility model provides a diaphragm structure, through at the ceramic layer and/or the partial region of glue film is along the thickness direction orientation the sunken recess that is formed with in base member layer to cut diaphragm structure's middle zone and thin and form concave type, with the thickness that reduces diaphragm middle zone, can reserve the inflation space for electric core pole piece, can reserve the electrolyte passageway for the middle zone of utmost point group simultaneously, make the battery in the circulation later stage, can in time supply electrolyte, and the recess can not increase battery system's complexity, easily realizes the industrialization. The battery cyclic expansion force can be reduced, the expansion force release of the middle part of the pole piece is facilitated, and the condition of lithium precipitation in the middle area of the battery negative pole piece is improved.

Description

Diaphragm structure and battery

Technical Field

The utility model relates to a battery technology field, concretely relates to diaphragm structure and battery.

Background

During the charging and discharging process of the battery, because lithium ions are continuously removed and inserted, the volume of the battery can expand in a certain proportion, so that the battery generates a certain expansion force. The swelling force not only deteriorates the safety of the battery system but also deteriorates the battery life. In addition, the expansion force increases along with the increase of the cycle number of the battery, particularly for a laminated battery, the edge parts of the positive and negative electrode plates have higher freedom degree, and can release certain force in the length direction or the width direction, but for the middle part of the electrode plate, the force can only be released in the thickness direction due to mutual extrusion among the upper, lower, left and right particles. Therefore, when the number of pole pieces in the battery is increased and the assembly ratio is increased when the gap in the aluminum case is constant, the expansion force in the thickness direction is increased, the transmission of lithium ions is limited, and the internal impedance of the battery is increased, resulting in a rapid decrease in the capacity of the battery. And when the bulging force increase of battery, can aggravate the extrusion between positive and negative pole piece and the diaphragm, lead to the electrolyte of circulation in-process utmost point group middle part to be extruded to free electrolyte can't in time supply in the circulation later stage casing to utmost point group in the middle of, lead to the ion channel disappearance, lithium is appeared analysing in the negative pole middle part, produces the potential safety hazard.

SUMMERY OF THE UTILITY MODEL

Therefore, the to-be-solved technical problem of the utility model lies in overcoming the difficult defect of releasing of expansibility at pole piece middle part among the prior art to a diaphragm structure that can improve the expansibility release degree at pole piece middle part is provided.

The utility model discloses another technical problem who solves lies in overcoming the difficult defect of releasing of expansibility at pole piece middle part among the prior art to a battery of expansibility release degree that can improve the pole piece middle part is provided.

In order to solve the above technical problem, the utility model provides a pair of diaphragm structure, include:

a substrate layer;

the ceramic layer is arranged on at least one side of the substrate layer along the thickness direction;

the adhesive layer is used for bonding the substrate layer and the ceramic layer;

and a groove is formed in a part of the ceramic layer and/or the adhesive layer in a manner that the part of the ceramic layer and/or the adhesive layer is sunken towards the substrate layer along the thickness direction.

Optionally, the groove extends from a center line of the diaphragm structure in the width direction toward both sides.

Optionally, the width of the groove is L1, wherein L1 is greater than or equal to 5mm and less than or equal to 10mm.

Optionally, the depth of the groove in the thickness direction is H1, wherein H1 is more than or equal to 1um and less than or equal to 3um.

Optionally, the ceramic layer has a thickness of H2, wherein H2=2um.

Optionally, the thickness of the glue layer is H3, wherein H3=1um.

Optionally, the thickness of the base layer is H4, wherein H4=7um.

Optionally, the material of the substrate layer includes at least one of PP and PE, and the material of the ceramic layer includes alumina.

The utility model provides a battery, include:

a housing;

and a diaphragm structure as described above disposed within the housing; and two adjacent diaphragm structures are stacked in the thickness direction.

Optionally, the positions of the grooves of two adjacent diaphragm structures correspond to each other.

The utility model discloses technical scheme has following advantage:

1. the utility model provides a diaphragm structure, through at the ceramic layer and/or the partial region of glue film is along the thickness direction orientation the sunken recess that is formed with in base member layer to cut diaphragm structure's middle zone and form concave type, with the thickness that reduces diaphragm middle zone, can reserve the expansion space for electric core pole piece, can reserve the electrolyte passageway for the middle zone of utmost point group simultaneously, make the battery in the circulation later stage, can in time supply electrolyte, and the recess can not increase battery system's complexity, easily realizes the industrialization. The battery cyclic expansion force can be reduced, the expansion force release of the middle part of the pole piece is facilitated, and the condition of lithium precipitation in the middle area of the battery negative pole piece is improved.

2. The utility model provides a diaphragm structure, through with the recess by diaphragm structure's central line extends towards both sides along width direction to can make the recess be located diaphragm structure's middle part position effectively improves the expansive force release of pole piece middle part.

3. The utility model provides a diaphragm structure, through setting up the width of recess is L1 to inject 5mm and be less than or equal to L1 and be less than or equal to 10mm, thereby can guarantee to reserve wide enough electrolyte passageway for utmost point group middle zone, convenient in time supplementary electrolyte.

4. The utility model provides a diaphragm structure, through setting up the recess is H1 and inject 1um along the degree of depth of thickness direction and be less than or equal to H1 and be less than or equal to 3um to can reduce the thickness of diaphragm middle zone, reserve the inflation space for electric core pole piece, reduce battery circulation bulging force, make things convenient for the bulging force release of pole piece middle part.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic cross-sectional view of the membrane structure of the present invention;

fig. 2 is a schematic size diagram of the diaphragm structure of the present invention in a cross-sectional state.

Description of reference numerals:

1-ceramic layer, 2-adhesive layer, 3-substrate layer and 11-groove.

Detailed Description

The technical solutions of the present invention will be described more clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

Example one

With reference to fig. 1-2, the diaphragm structure provided in this embodiment includes:

a base layer 3;

a ceramic layer 1 provided on at least one side of the base layer 3 in the thickness direction;

the adhesive layer 2 is used for bonding the substrate layer 3 and the ceramic layer 1;

the ceramic layer 1 and/or the partial area of the adhesive layer 2 are recessed towards the substrate layer 3 along the thickness direction to form a groove 11.

The diaphragm structure provided by the embodiment takes PP, PE or a multi-layer composite diaphragm as a substrate, the surface of the diaphragm structure is coated with PVDF glue, a layer of nano-scale alumina material is additionally arranged, the nano-scale alumina material is tightly bonded with the substrate through special process treatment, and the high temperature resistance and the safety of the lithium ion battery can be obviously improved by adding the nano-scale alumina material.

As a specific implementation form, as shown in fig. 1, the ceramic layer 1 is provided with the substrate layers 3 on both sides in the thickness direction, and the substrate layers 3 on both sides are bonded to the ceramic layer 1 through the glue layers 2.

Preferably, the recess 11 is formed by recessing a central region of the ceramic layer 1 in the thickness direction toward the base layer 3.

The diaphragm structure that this embodiment provided, through at ceramic layer 1 and/or the partial area of glue film 2 is along the thickness direction orientation the sunken recess 11 that is formed with of base member layer 3 to cut the middle zone of diaphragm structure thin and form concave type, with the thickness that reduces diaphragm middle zone, can reserve the inflation space for electric core pole piece, can reserve the electrolyte passageway for the middle zone of utmost point group simultaneously, make the battery in circulation later stage, can in time supply electrolyte, and the recess can not increase battery system's complexity, easily realize the industrialization.

Optionally, the diaphragm structure provided by this embodiment can reduce the battery cyclic expansion force, facilitate the release of the expansion force at the middle part of the pole piece, and improve the lithium precipitation condition of the middle area of the battery negative pole piece.

Additionally, the battery prepared by adopting the diaphragm structure with the groove can improve the expansion space of the middle area of the battery, reserve an electrolyte channel, and effectively improve the expansion force cycle performance through theoretical analysis and simulation.

The separator structure of the present application may be applied to a pole piece, and a plurality of pole pieces may be stacked in the thickness direction to form a pole group. Because the diaphragm structure of every pole piece all is provided with recess 11 to after a plurality of pole pieces are folded along thickness direction, the middle zone of the utmost point group that forms can form along length direction leads to, makes things convenient for the circulation of electrolyte. The pole set may be a lamination or a winding process.

The grooves 11 in the diaphragm structure may be pressed by means of a press roll. The middle area of compression roller along axial direction outwards protrudes the setting, rolls through the length direction that makes the compression roller follow the diaphragm structure to can be at ceramic layer 1 and/or the middle area of glue film 2 is along the thickness direction orientation the base member layer 3 suppression forms recess 11, and preparation method is simple, realizes industrialization batch production easily.

Specifically, the grooves 11 extend from the center line of the diaphragm structure toward both sides in the width direction. The groove 11 extends from the central line of the diaphragm structure towards two sides along the width direction, so that the groove 11 can be positioned in the middle of the diaphragm structure, and the expansion force release of the middle part of the pole piece is effectively improved.

Specifically, the width of the groove 11 is L1, wherein L1 is more than or equal to 5mm and less than or equal to 10mm. By setting the width of the groove 11 to be L1 and limiting L1 to be more than or equal to 5mm and less than or equal to 10mm, an electrolyte channel with sufficient width can be reserved in the middle area of the pole group, and electrolyte can be conveniently supplemented in time.

Specifically, the depth of the groove 11 along the thickness direction is H1, wherein H1 is more than or equal to 1um and less than or equal to 3um. Through setting up recess 11 is H1 and inject 1um and be less than or equal to H1 and be less than or equal to 3um along the degree of depth of thickness direction to can reduce the thickness of diaphragm middle zone, reserve the inflation space for electric core pole piece, reduce battery cycle expansibility, make things convenient for the expansibility release of pole piece middle part.

Specifically, the thickness of the ceramic layer 1 is H2, wherein H2=2um.

Specifically, the thickness of glue layer 2 is H3, wherein H3=1um.

Specifically, the thickness of the base layer 3 is H4, where H4=7um.

The diaphragm structure is pressed in the process of coating the ceramic layer 1 or the adhesive layer 2, so that the middle of the diaphragm structure is concave. As a specific example, the parameters of the diaphragm structure may be: the thickness of the base layer 3 is H4=7um, the thicknesses of the ceramic layers 1 on both sides in the thickness direction are both H2=2um, and the thicknesses of the adhesive layers on both sides in the thickness direction are both H3=1um.

Specifically, the material of the substrate layer 3 includes at least one of PP and PE, and the material of the ceramic layer 1 includes aluminum oxide.

Example two

The present embodiment provides a battery including:

a housing;

and a diaphragm structure as described in the first embodiment disposed within the housing; two adjacent diaphragm structures are stacked along the thickness direction.

The open end of the shell is also suitable for covering a battery core cover plate.

Specifically, the positions of the grooves 11 of the adjacent two pieces of diaphragm structures correspond.

Through adjacent two the recess 11 position of diaphragm structure is corresponding to can make adjacent two the recess 11 of diaphragm structure is corresponding and superpose, widens the electrolyte passageway that the utmost point organizes middle zone reservation, increases the circulation ability of electrolyte.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious changes and modifications can be made without departing from the scope of the invention.

Claims

1. A diaphragm structure, comprising:

a base layer (3);

the ceramic layer (1) is arranged on at least one side of the substrate layer (3) along the thickness direction;

the adhesive layer (2) is used for bonding the substrate layer (3) and the ceramic layer (1);

and a groove (11) is formed in a way that partial area of the ceramic layer (1) and/or the adhesive layer (2) is sunken towards the substrate layer (3) along the thickness direction.

2. Diaphragm structure according to claim 1, wherein the groove (11) extends from the centre line of the diaphragm structure in the width direction towards both sides.

3. Diaphragm structure according to claim 2, wherein the width of the groove (11) is L1, wherein L1 is ≦ 5mm ≦ 10mm.

4. Diaphragm structure according to claim 1, wherein the depth of the groove (11) in the thickness direction is H1, wherein 1um ≦ H1 ≦ 3um.

5. Diaphragm structure according to claim 4, wherein the thickness of the ceramic layer (1) is H2, wherein H2=2um.

6. Membrane structure according to claim 4, wherein the thickness of the glue layer (2) is H3, wherein H3=1um.

7. Diaphragm structure according to any of claims 1-6, characterized in that the matrix layer (3) has a thickness of H4, wherein H4=7um.

8. Separator structure according to any of claims 1-6, characterized in that the material of the matrix layer (3) comprises at least one of PP, PE and the material of the ceramic layer (1) comprises alumina.

9. A battery, comprising:

a housing;

and a diaphragm structure according to any one of claims 1 to 8 disposed within the housing; two adjacent diaphragm structures are stacked along the thickness direction.

10. The battery according to claim 9, wherein the grooves (11) of two adjacent sheets of the separator structures correspond in position.