CN218299960U

CN218299960U - Battery pack and power battery pack

Info

Publication number: CN218299960U
Application number: CN202222421933.0U
Authority: CN
Inventors: 董爱雪; 张士荟; 牛力; 赵幸一
Original assignee: China Lithium Battery Technology Co Ltd
Current assignee: China Lithium Battery Technology Co Ltd
Priority date: 2022-09-13
Filing date: 2022-09-13
Publication date: 2023-01-13
Anticipated expiration: 2032-09-13

Abstract

The utility model discloses a group battery and power battery package. The battery pack comprises two end plates and at least two single battery cells arranged between the two end plates in the thickness direction of the end plates, wherein a heat insulation structure is arranged between the end plates and the adjacent single battery cells and/or between the two adjacent single battery cells; the heat insulation structure comprises a packaging piece and a heat insulation piece arranged in the packaging piece; the heat insulation piece comprises an outer rectangular frame and an inner rectangular frame which is arranged in a penetrating manner. The utility model provides a group battery and power battery package, the heat insulating part who has interior rectangle frame structure and outer rectangle frame structure because of adopting to be penetrating form setting utilizes the air as thermal-insulated medium, to the compressive stress of heat insulating part main part when reducing monomer electric core inflation, avoids the heat insulating part structure to be destroyed and leads to the reduction of heat-proof quality to guarantee that adjacent monomer electric core can maintain excellent thermal-insulated state for a long time, still can avoid the encapsulation membrane to prop brokenly and the encapsulation that leads to is inefficacy.

Description

Battery pack and power battery pack

Technical Field

The utility model relates to a power battery and thermal-insulated technical field especially relates to a group battery and power battery package.

Background

Generally, the structure of a power battery pack mainly includes a battery box and a battery module, and the battery module is usually formed by arranging a plurality of battery cells in sequence. The safety problem of the power battery pack is mainly the thermal runaway problem. When monomer electricity core took place thermal runaway, the electric core temperature can acutely rise, and its structure also can take place the inflation deformation because of the high temperature effect, and thermal runaway monomer electricity core can be fast with heat transfer give with it adjacent monomer electricity core, and the inside temperature of battery package when this process can risees and causes whole package thermal runaway.

Therefore, can set up the heat insulating part between adjacent monomer electricity core usually, if adopt the mica sheet as the heat insulating part usually to when individual electricity core appears under the high temperature condition in the battery module under the extreme condition such as overcharge, thermal runaway, can delay or avoid adjacent electricity core to a certain extent overheated then also the risk of thermal runaway appears. However, in an extreme case of overcharge or thermal runaway, the thermal insulation member is pressed by excessive expansion of the battery cell, and the thermal insulation member also undergoes bulging deformation, so that the packaging film is burst, and the packaging of the thermal insulation member fails.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, one of the objects of the utility model is to provide a battery pack, which adopts a heat insulation piece with a containing space of battery expansion deformation, and can avoid the occurrence of package failure caused by excessive compression deformation when the battery core is expanded and extruded.

Specifically, the battery pack provided by the utility model comprises two end plates and at least two single battery cells arranged between the two end plates along the thickness direction of the end plates, wherein a heat insulation structure is arranged between the end plates and the adjacent single battery cells and/or between the two adjacent single battery cells;

the heat insulation structure comprises a packaging piece and a heat insulation piece arranged in the packaging piece;

the heat insulation piece is adjacent to the large face of the single battery cell, the heat insulation piece comprises an outer rectangular frame and an inner rectangular frame, and the inner rectangular frame is arranged in a penetrating mode.

As a second object of the present invention, it is to provide a power battery pack, which includes the aforementioned battery pack.

Compared with the prior art, the utility model provides a group battery and power battery package utensil's beneficial effect lies in:

the heat insulation structure adopts a heat insulation piece which is arranged in a transparent manner and provided with an inner rectangular frame structure and an outer rectangular frame structure, so that air is utilized as a heat insulation medium through the formed transparent hollow structure, the compression stress to the heat insulation piece main body when the single battery cells expand is reduced, the reduction of heat insulation performance caused by the damage of the heat insulation piece structure is avoided, the adjacent single battery cells can be ensured to maintain an excellent heat insulation state for a long time, and meanwhile, the heat insulation effect is better compared with a heat insulation material with pressure failure;

and the inner rectangular frame structure arranged in a penetrating manner can provide a larger expansion space for the single battery cell, so that the stress at the middle position of the heat insulation piece is prevented from being excessively concentrated, and the packaging failure caused by the fact that the packaging film is broken can be avoided.

Drawings

Fig. 1 is a schematic structural view of a battery module with a casing removed from a battery pack according to the present invention;

fig. 2 is a schematic view of a heat insulation structure having a first packaging structure in the battery module shown in fig. 1;

fig. 3 is a schematic view of a heat insulation structure having a second package structure in the battery module shown in fig. 1.

Reference numbers:

1. a thermally insulating structure; 2. packaging the film; 11. a single cell; 3. an outer rectangular frame; 4, an inner rectangular frame body; 21. a first encapsulation film; 22. a second encapsulation film; 14. an end plate; 13. a cuff; 221. a square outer frame; 222. and a square inner frame.

Detailed Description

For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

In the description of the present invention, it should be noted that, if the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like refer to the orientation or positional relationship indicated on the drawings, it is only for convenience of description and simplification of the description, and it is not intended to 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.

In the description of the present invention, unless explicitly specified or limited otherwise, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more; the term "and/or" includes any and all combinations of one or more of the associated listed items. In particular, references to "the" object or "an" object are also intended to mean one of possibly multiple such objects.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of the invention and the above description of the drawings are intended to cover non-exclusive inclusions.

Further, in the description of the present invention, it should be understood that the terms "upper", "lower", "inner", "outer", and the like are used for descriptive purposes only and not for purposes of limitation, as defined by the accompanying drawings. It will also be understood that, in this context, when an element or feature is referred to as being "on", "under", or "inner", "outer" with respect to another element(s), it can be directly on "," under ", or" inner "," outer "with respect to the other element(s), or indirectly on", "under", or "inner", "outer" with respect to the other element(s) via intervening elements.

The utility model provides a group battery includes the shell body and locates the finger battery module in this shell body, for the convenience of illustration and understanding, omits the battery module structure after the shell body and is shown in FIG. 1. This battery module includes two end plates 14 and locates a plurality of monomer batteries 11 of arranging in proper order along the thickness direction of end plate 14 between the end plate 14, between end plate 14 and the adjacent monomer battery 11 with it, be provided with thermal-insulated structure between two adjacent monomer batteries 11, it is adjacent with the big face of monomer battery 11 that also thermal-insulated structure is.

Specifically, as shown in fig. 2, a thermal insulation structure having a first package structure is illustrated. The heat insulation structure comprises a packaging piece and a heat insulation piece arranged in the packaging piece, wherein the thickness of the heat insulation piece is generally between 0.2 and 2 mm; this heat insulating part includes outer rectangular frame 3 and interior rectangular frame 4, and wherein this interior rectangular frame 4 is penetrating form setting, also, and this interior rectangular frame 4 is middle fretwork setting, and the packaging part is a

slice encapsulation membrane

2, and 2 length of this encapsulation membrane are greater than the length of heat insulating part, and length direction is the X that fig. 2 shows to.

The packaging film 2 has a square outer frame and a square inner frame (not indicated by reference numerals due to the relationship of the figure), and the positions of the square outer frame and the square inner frame correspond to the positions of the outer rectangular frame 3 and the inner rectangular frame 4 of the heat insulation part respectively, and after the packaging film 2 covers the long side of the top of the outer rectangular frame 3, the packaging film covers one side surface of the heat insulation part facing the large surface of the monomer electric core 11 and turns over to cover the other opposite side surface by taking the long side of the bottom as an axis along the width direction of the large surface of the outer rectangular frame, namely the Y direction in the figure. Or, the short side in the width direction of the outer rectangular frame 3 of the heat insulating material is turned over and wrapped with an axis. The specific coating method is not limited to the embodiment, and in short, the sealing film 2 coats the large surface of the heat insulating material in a continuous coating manner. And a third seal is formed on the periphery of the inner rectangular frame 4 of the heat insulation piece.

The material of the heat insulation piece in the embodiment may be a phase change material, for example, a solid-gas phase change material, which changes a material state and absorbs a large amount of latent heat along with a temperature change, so that the heat of a thermal runaway single cell is prevented from being transferred to an end plate or an adjacent single cell, and the constraint failure outside a battery module or the complete pack failure of a battery pack can be prevented; of course, the heat insulation member may also be one or more of phase change material, aerogel, foam or silica gel; the package part can adopt one or more than one of an aluminum plastic film, an EVA resin, a PI film, a PET film, a PP film, a PC film, a PVC film, a PU film or a graphite film.

Further, as shown in fig. 1 and fig. 2, the outer rectangular frame 4 and the inner rectangular frame 3 have a height difference D1 along the height direction of the unit cell 11, i.e. the Y direction in fig. 2, and the value of D1 is greater than or equal to 1/6 of the height D of the unit cell, and preferably may be 1/5. Along the length direction of the single battery cell, the outer rectangular frame 4 and the inner rectangular frame 3 have a width difference H1, where H1 is greater than or equal to 1/4 of the width H of the single battery cell, and may also be 1/2, for example. When the single battery cell is out of control thermally, the single battery cell is most seriously deformed by bulging at the midpoint of the large surface, commonly called as a bulge. The utility model discloses a group battery through adopting the thermal-insulated structure that so size set up, can avoid the region of monomer electricity core drum belly, guarantees that thermal-insulated structure can not the pressurized deformation. Therefore, the heat insulation effect of the heat insulation structure can be guaranteed, and a sufficient expansion deformation space can be provided for the single battery cell.

Fig. 3 shows a schematic view of a heat insulation structure 1 having a second encapsulation structure for use in a battery pack. The thermal insulation structure also comprises a thermal insulation member and an enclosure member, wherein the structure of the thermal insulation member is the same as that illustrated and described in fig. 1-2, and the detailed description thereof is omitted.

In this second encapsulation structure, the encapsulation member includes a first encapsulation film 21 and a second encapsulation film 22 each having a square outer frame 221 and a square inner frame 222, which correspond to the outer rectangular frame 3 and the inner rectangular frame 4 of the heat insulating member, respectively. The heat insulation piece is arranged between the two packaging films, the peripheral sides of the two packaging films are sealed by hot pressing to form a first seal, and a vacuum heat insulation packaging cavity is formed. Second seals are formed on the peripheral sides of the outer rectangular frame 3 and the inner rectangular frame 3 of the heat insulating member, respectively.

The utility model also provides a power battery package structure, it includes the group battery of aforementioned mentioning.

The utility model discloses a thermal-insulated structure is the interior rectangle frame structure that penetrating form set up through it, utilizes the air as thermal-insulated medium, behind the packaging film seal encapsulation heat insulating part, under the effect of the big face extrusion that receives monomer electricity core, the seal membrane can closely laminate with the heat insulating part further. Particularly, when two sides of the heat insulation structure are both extruded by the large surfaces of the single battery cells, the air encapsulated between the sealing elements can be compressed in a narrow encapsulation space to form certain air pressure so as to resist the compression stress to the heat insulation element main body when the single battery cells expand and avoid stress concentration, so that the heat insulation element can be further prevented from being excessively extruded to reduce the heat resistance, and meanwhile, the contact between the adjacent single battery cells can be effectively prevented or relieved; and, this be the interior rectangle frame structure that penetrating form set up can provide the accommodation space that warp for the inflation of monomer electricity core to the condition that the packaging part that the bulging deformation that avoids the heat insulating part leads to breaks the inefficacy appears, thereby can improve the security of group battery and power battery package.

Various other modifications and changes can be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims.

Claims

1. A battery pack comprises two end plates (14) and at least two single battery cells (11) arranged between the two end plates (14) along the thickness direction of the end plates (14), and is characterized in that a heat insulation structure is arranged between the end plates (14) and the adjacent single battery cells (11) and/or between the two adjacent single battery cells (11);

the heat insulation piece is adjacent to the large face of the single battery cell (11), the heat insulation piece comprises an outer rectangular frame (3) and an inner rectangular frame (4), and the inner rectangular frame (4) is arranged in a penetrating mode.

2. The battery pack according to claim 1, wherein the encapsulation includes a first encapsulation film (21) and a second encapsulation film (22) each having a square outer frame and a square inner frame;

a first seal is formed at the peripheral side joint of the first packaging film (21) and the second packaging film (22);

second seals are formed on the peripheral sides of the outer rectangular frames (3) and the peripheral sides of the inner rectangular frames (4) of the heat insulation piece.

3. The battery pack according to claim 1, wherein the package member includes a package film having a square outer frame and a square inner frame, the package film having a continuous covering surface that is turned around a long side or a short side of the heat insulating member as an axis to cover the heat insulating member;

and a third seal is arranged on the peripheral side of the inner rectangular frame (4) of the heat insulation piece.

4. The battery pack according to any one of claims 1 to 3, wherein the thermal insulation member is one or more of a phase change material, aerogel, foam or silica gel.

5. The battery pack according to any one of claims 1 to 3, wherein the package member is one or more of an aluminum plastic film, an EVA resin, a PI film, a PET film, a PP film, a PC film, a PVC film, a PU film, or a graphite film.

6. The battery pack according to claim 1, wherein the outer rectangular frame (3) and the inner rectangular frame (4) have a height difference D1 along the height direction of the unit cell (11), and D1 is greater than or equal to 1/6 of the height D of the unit cell.

7. The battery pack according to claim 6, wherein the outer rectangular frame (3) and the inner rectangular frame (4) have a height difference D1 along the height direction of the single battery cells (11), and D1 is greater than or equal to 1/5 of the height D of the single battery cells (11).

8. The battery pack according to claim 1, wherein the outer rectangular frame (3) and the inner rectangular frame (4) have a width difference H1 along the height direction of the unit cells (11), and the width difference H1 is greater than or equal to 1/4 of the width H of the unit cells (11).

9. The battery pack according to claim 8, wherein the outer rectangular frame (3) and the inner rectangular frame (4) have a width difference H1 along the height direction of the unit cells (11), and H1 is greater than or equal to 1/2 of the width H of the unit cells (11).

10. A power pack comprising a battery pack according to any one of claims 1 to 9.