CN220474715U - Battery pack - Google Patents

Abstract

The utility model relates to the technical field of batteries, and provides a battery pack, which comprises: the single batteries comprise pressure relief structures positioned on the side surfaces of the single batteries; the bottom supporting plate is supported on the side surface of the single battery, provided with the pressure relief structure, and comprises a plurality of protruding parts facing one side of the single battery, a first groove is formed among the protruding parts, and a second groove is formed on one side, deviating from the single battery, of the protruding parts; wherein, the battery cell supports on the bellying, and the pressure release structure and the first recess of battery cell set up relatively. The battery pack provided by the present disclosure can improve the heat insulation effect between the unit cells and other structures.

Description

Battery pack

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery pack.

Background

In the related art, a battery pack generally includes a single battery and a supporting base plate for supporting the single battery, and when the single battery is subjected to thermal runaway pressure release, generated heat is easily transferred between the battery supporting base plates. On one hand, the rapid heat conduction between the single battery and the supporting bottom plate can cause great influence of the environmental temperature on the single battery or cause great influence of the single battery on the environmental temperature; on the other hand, the single cells can conduct heat through the supporting bottom plate, so that the thermal runaway range of the single cells is easily expanded, and meanwhile, the sealing parts in the battery pack are easily damaged.

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the present disclosure and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The utility model provides a battery pack, which can solve the technical problems of poor heat insulation capability and easy expansion of thermal runaway range of the battery pack.

The present utility model first provides a battery pack including: the single batteries comprise pressure relief structures positioned on the side surfaces of the single batteries; the bottom supporting plate is supported on the side surface of the single battery, provided with the pressure relief structure, and comprises a plurality of protruding parts facing one side of the single battery, a first groove is formed among the protruding parts, and a second groove is formed on one side, deviating from the single battery, of the protruding parts; wherein, the battery cell supports on the bellying, and the pressure release structure and the first recess of battery cell set up relatively.

In the utility model, the convex part is provided with the second groove which is positioned at the side surface deviating from the single battery, namely, the convex part is of a hollow structure, and the heat conduction rate between the single battery and the bottom of the battery pack and between the single battery and the single battery can be reduced due to the fact that the heat resistance of air is large. On one hand, the utility model can improve the heat insulation capability between the battery pack and the external environment; on the other hand, the utility model can also reduce the expansion of the thermal runaway range of the single battery and the risk of damaging the insulating piece in the battery pack; in yet another aspect, the first recess may form a relief space of the relief structure to facilitate relief of the relief structure.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

For a better understanding of the present disclosure, reference may be made to the embodiments illustrated in the following drawings. The components in the drawings are not necessarily to scale and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, the relevant elements or components may have different arrangements as known in the art. Furthermore, in the drawings, like reference numerals designate identical or similar parts throughout the several views.

Wherein:

fig. 1 is a schematic view of the structure of an exemplary embodiment of a battery pack of the present disclosure;

fig. 2 is a partial schematic structure of the battery pack shown in fig. 1;

fig. 3 is a schematic view of a partial area a in the battery pack shown in fig. 2;

FIG. 4 is a schematic view of the structure of a bottom plate in the battery pack of FIG. 1;

FIG. 5 is a schematic view of a portion B of the bottom pallet of FIG. 4;

FIG. 6 is a schematic view of the bottom pallet of FIG. 4 from another perspective;

fig. 7 is a schematic structural view of a unit cell in an exemplary embodiment of a battery pack of the present disclosure;

fig. 8 is a schematic structural view of another exemplary embodiment of a battery pack of the present disclosure;

fig. 9 is a schematic view of the structure of the bottom plate in the battery pack shown in fig. 8.

Reference numerals illustrate:

1. a single battery; 1x, single battery rows; 2. a bottom support plate; 5. a sub-bottom pallet; 6, a pressure relief channel; 7. a support base plate; 11. a pressure relief structure; 21. a boss; 22. a second groove; 23. a first groove; 121. a circular end face; 122. a curved surface; 211. a sub-protrusion; 231. a main body groove; 232. a connecting groove; 231x, main body slot rows; 233. opening holes; 1211. and (5) scoring.

Detailed Description

The technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the exemplary embodiments of the present disclosure. The example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it is therefore to be understood that various modifications and changes may be made to the example embodiments without departing from the scope of the present disclosure.

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

Unless specified or indicated otherwise, the terms "connected," "fixed," and the like are to be construed broadly and are, for example, capable of being fixedly connected, detachably connected, or integrally connected, electrically connected, or signally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the terms in the present disclosure may be understood by those skilled in the art according to the specific circumstances.

Further, in the description of the present disclosure, it should be understood that the terms "upper", "lower", "inner", "outer", and the like, as described in the example embodiments of the present disclosure, are described with the angles shown in the drawings, and should not be construed as limiting the example embodiments of the present disclosure. It will also be understood that in the context of an element or feature being "on," "under," or "in" or "out" of another element or feature being "on," "under" or "in" or "out" of the other element or elements, it can be directly connected to the other element or elements, or indirectly connected to the other element or elements via intervening elements.

The present exemplary embodiment first provides a battery pack, as shown in fig. 1-6, fig. 1 is a schematic structural diagram of an exemplary embodiment of the battery pack of the present disclosure, fig. 2 is a schematic structural diagram of a portion of the battery pack shown in fig. 1, fig. 3 is a schematic structural diagram of a portion a of the battery pack shown in fig. 2, fig. 4 is a schematic structural diagram of a bottom plate of the battery pack shown in fig. 1, fig. 5 is a schematic structural diagram of a portion B of the bottom plate shown in fig. 4, and fig. 6 is a schematic structural diagram of another view of the bottom plate shown in fig. 4.

The battery pack may include: a plurality of single batteries 1 and a bottom support plate 2, wherein the single batteries 1 comprise pressure release structures 11 positioned on the side surfaces of the single batteries; the bottom plate 2 is supported on the side surface of the single battery 1, on which the pressure relief structure 11 is arranged, the bottom plate 2 comprises a plurality of protruding parts 21 facing one side of the single battery 1, a first groove 23 is formed among the protruding parts 21, and a second groove 22 is formed on one side of the protruding part 21, which is away from the single battery 1; the single battery 1 is supported on the protruding portion 21, and the pressure release structure 11 of the single battery 1 and the first groove 23 are disposed opposite to each other.

In the present exemplary embodiment, the side of the protruding portion 21 facing away from the unit cell 1 is formed with the second groove 22, that is, the protruding portion 21 is of a hollow structure, and the present exemplary embodiment can reduce the heat conduction rate between the unit cell 1 and the bottom of the battery pack, and between the unit cell 1 and the unit cell 1, due to the large thermal resistance of air. On one hand, the utility model can improve the heat insulation capability between the battery pack and the external environment; on the other hand, the present exemplary embodiment can also reduce the expansion of the thermal runaway range of the unit cells, and reduce the risk of damage to the insulators in the battery pack; in yet another aspect, the first recess 23 may form a relief space of the relief structure to facilitate relief of the relief structure.

It should be noted that, in this exemplary embodiment, the structure a and the structure B are disposed opposite to each other, and it is understood that the orthographic projection of the structure a on the projection plane at least partially overlaps the orthographic projection of the structure B on the projection plane, and the projection plane is a plane perpendicular to the distribution direction of the structures a and B. The bottom plate 2 is supported on the side surface of the single battery 1 where the pressure relief structure 11 is provided, which is understood that the bottom plate 2 is directly supported on the side surface of the single battery 1 where the pressure relief structure 11 is provided, that is, the bottom plate 2 is directly contacted with the single battery 1; or, the bottom plate 2 is indirectly supported on the side surface of the single battery 1 where the pressure relief structure 11 is arranged, that is, other structures are arranged between the bottom plate 2 and the single battery 1.

In this exemplary embodiment, the front projection of the relief structure 11 on the projection plane may be located on the front projection of the first groove 23 on the projection plane, i.e. the front projection of the relief structure 11 on the projection plane is located within the front projection of the first groove 23 on the projection plane, or the front projection of the relief structure 11 on the projection plane coincides with the front projection of the first groove 23 on the projection plane.

In this exemplary embodiment, as shown in fig. 1 to 6, the bottom plate 2 may include a plurality of the protrusions 21, and the plurality of the protrusions 21 may extend in a first direction X and be spaced apart in a second direction Y, and the first direction X and the second direction Y may intersect, for example, the first direction X and the second direction Y may be perpendicular. The unit cell 1 is supported on two adjacent protruding portions 21 in the second direction Y, and the pressure release structure 11 of the unit cell 1 and the first groove 23 between the two protruding portions 21 supporting the unit cell 1 are disposed opposite to each other. On the one hand, the present exemplary embodiment provides the protruding part 21 in the shape of a long bar extending in the first direction X, and the long bar-shaped protruding part 21 has a relatively stable structure, so that the overall strength of the battery pack can be improved. On the other hand, the present exemplary embodiment sets the protruding portions 21 at intervals in the second direction Y, and heat cannot be transferred between the unit cells supported by the different protruding portions 21 through the protruding portions 21, so that the setting can further reduce the risk of the expansion of the thermal runaway range of the unit cells.

In the present exemplary embodiment, as shown in fig. 1 to 6, a plurality of the unit cells 1 may be distributed in an array along the first direction X and the second direction Y; the plurality of unit cells 1 distributed in the first direction X are supported on the same group of adjacent protruding portions 21. The distribution mode of the single batteries 1 and the strip-shaped structure of the protruding part 21 are correspondingly arranged, and more single batteries can be arranged on the bottom supporting plate 2, so that the energy density of the battery pack is improved.

In the present exemplary embodiment, as shown in fig. 1 to 6, the single cells 1 distributed in the first direction X form a single cell row 1X, and at least part of the protruding portions 21 are supported below two adjacent single cell rows 1X in the second direction Y. I.e. two adjacent cell rows 1x share the same protrusion 21. On one hand, the arrangement can increase the distribution density of the single batteries, thereby improving the energy density of the battery pack; on the other hand, the protruding portion 21 common to the adjacent two rows of the unit cell rows 1x may have a larger size in the second direction Y, so that the protruding portion 21 may be easily molded; on the other hand, the convex portion 21 having a larger size in the second direction Y has a better structural stability.

In the second direction Y, the protruding portion 21 located at the edge of the bottom plate 2 is supported only under one of the cell rows 1x.

It should be understood that in other exemplary embodiments, the protruding portion 21 may have other structures, for example, the protruding portion 21 may have an annular structure, the unit cells and the protruding portions may be disposed in a one-to-one correspondence, the unit cells are supported on the protruding portions corresponding thereto, and the area surrounded by the annular protruding portions forms the second groove.

In the present exemplary embodiment, as shown in fig. 1 to 6, the second groove 22 formed by the convex portion 21 extends in the extending direction of the convex portion 21. This setting can make bellying 21 each position all correspond and be provided with second recess 22 to can guarantee that bottom plate 2 all has better adiabatic effect to the monomer battery 1 of optional position.

It should be appreciated that in other exemplary embodiments, a plurality of reinforcing portions may be disposed in the strip-shaped second groove 22 at intervals along the extending direction thereof, and the reinforcing portions may increase the overall strength of the bottom plate 2.

In this exemplary embodiment, as shown in fig. 1 to 6, the first groove 23 may include: the plurality of main body grooves 231 and the plurality of connecting grooves 232 are distributed at intervals along the first direction X, the main body grooves 231 and the single batteries 1 are arranged in a one-to-one correspondence manner, and the main body grooves 231 and the corresponding pressure release structures 11 of the single batteries 1 are arranged oppositely. The orthographic projection of the pressure relief structure 11 on the projection plane may be located on the orthographic projection of the main body groove 231 on the projection plane, where the projection plane is a plane perpendicular to the distribution direction of the pressure relief structure 11 and the main body groove 231. The connection groove 232 is connected between adjacent ones of the main body grooves 231 in the first direction X; wherein, the dimension S1 of the main body groove 231 in the second direction Y is greater than the dimension S2 of the connection groove 232 in the second direction Y. In the present exemplary embodiment, on the one hand, the main body groove 231 with a larger size in the second direction Y may reserve enough space for the pressure relief structure 11 to relieve pressure, so that the pressure relief structure 11 is relieved; on the other hand, the connection groove 232 having a smaller size in the second direction Y may allow the boss 21 to have a larger size in the second direction Y, and this arrangement may allow the boss 21 to have better structural stability.

In the present exemplary embodiment, as shown in fig. 1 to 6, opposite sides of the body groove 231 in the second direction Y are circular arcs, and opposite sides of the body groove 231 in the first direction X are straight lines. In the present exemplary embodiment, as shown in fig. 1 to 6, the connection groove 232 may be rectangular. It should be appreciated that in other exemplary embodiments, the body slot 231 may have other configurations, for example, the body slot 231 may have a rectangular shape, a triangular shape, a polygonal shape, an irregular pattern, or the like. Likewise, the connection groove 232 may have other structures, for example, the connection groove 232 may extend to be curved in the first direction X.

In the present exemplary embodiment, as shown in fig. 1 to 6, the dimension of the main body groove 231 in the second direction Y gradually decreases from the center position of the main body groove 231 in the first direction X to both sides away from the center position. The plurality of body grooves 231 distributed in the first direction X form a body groove row 231X, and the body grooves 231 are sequentially staggered in the first direction X in adjacent body groove rows 231X. Since the body grooves 231 are larger in the second direction Y, if the body grooves 231 in the adjacent body groove rows 231X are not staggered in the first direction X, the size of the protruding portions 21 between the body grooves 231 in the second direction Y is smaller, which may result in lower structural stability of the protruding portions 21. The present exemplary embodiment staggers the body grooves 231 in the first direction X in adjacent body groove rows 231X, and at the same time, since the size of the body grooves 231 in the second direction Y gradually decreases from the center position of the body grooves 231 in the first direction X to the sides away from the center position, the arrangement can avoid the direct opposition of the maximum size positions of the adjacent body grooves 231 in the second direction, so that the protruding portions 21 between the body grooves 231 can have a larger size in the second direction Y, and further the structural stability of the protruding portions 21 can be ensured.

In the present exemplary embodiment, as shown in fig. 1 to 6, the bottom chassis 2 includes a plurality of sub-chassis 5, and the plurality of sub-chassis 5 extend in a first direction X and are distributed along a second direction Y; the sub-bottom support plates 5 are arranged corresponding to at least one single battery row 1x, and the sub-bottom support plates 5 are used for supporting the single battery row 1x corresponding to the sub-bottom support plates. The present exemplary embodiment divides the bottom chassis 2 into a plurality of sub chassis 5, and on the one hand, the sub chassis 5 of a smaller size can be easily installed; on the other hand, when the bottom supporting plate 2 is locally damaged, the way of replacing the sub bottom supporting plate 5 is more convenient and cheaper; in yet another aspect, adjacent sub-base plates 5 may be spaced apart with a lesser thermal conduction rate between adjacent sub-base plates 5, which may further reduce the thermal conduction rate between adjacent cells 1 through base plate 2. It should be appreciated that in other exemplary embodiments, adjacent sub-floor boards 5 may also be provided in contact.

In this exemplary embodiment, as shown in fig. 1 to 6, the sub-bottom plates 5 may be disposed corresponding to two rows of the unit cell rows 1x. It should be understood that in other exemplary embodiments, the sub-bottom plates 5 may be disposed corresponding to the cell rows 1x of other rows. The number of rows of the single batteries corresponding to the sub-bottom plates 5 may be the same or different.

In this exemplary embodiment, as shown in fig. 1 to 6, the sub-bottom plate 5 includes sub-protrusions 211 near the edges thereof in the second direction Y, and in the sub-bottom plate 5 adjacent to each other in the second direction Y, two adjacent sub-protrusions 211 may be spliced to form the protrusion 21. The present exemplary embodiment sets the splicing position of the sub-bottom plate 5 at the position of the boss 21, that is, the first groove 23 is a non-splicing structure, which can reduce the risk that the pressure release structure 11 and the first groove 23 cannot be aligned due to an assembly error.

In the present exemplary embodiment, as shown in fig. 1 to 6, the bottom plate 2 may be a plastic suction member. A blister is a plastic article, typically made of thermoplastic. The plastic piece is made by heating and softening plastic sheet or sheet, then adsorbing it on mould by plastic sucking machine, cooling to form the required shape. The material of the suction member may include one or more of Polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and polyvinyl chloride (PVC). The plastic sucking piece is simple to mold and has better heat insulation capacity.

It should be appreciated that in other exemplary embodiments, the bottom plate 2 may also be formed of other materials, for example, the bottom plate 2 may be a metal piece.

In the present exemplary embodiment, as shown in fig. 1 to 6, the unit cell 1 may be a cylindrical cell. Fig. 7 is a schematic structural view of a unit cell in an exemplary embodiment of the battery pack of the present disclosure. In the present exemplary embodiment, the cylindrical battery may include a cylindrical battery case including two circular end faces 121 and a curved surface 122 between the two circular end faces 121. When the temperature of the single battery 1 is too high and the internal pressure is too high, the single battery 1 can be decompressed through the decompression structure 11. As shown in fig. 7, a circular end surface 121 of the unit cell 1 is formed with a closed-shaped notch 1211, and the circular end surface 121 is located in a region surrounded by the notch 1211 to form a pressure relief structure 11.

It should be appreciated that in other exemplary embodiments, the pressure relief structure 11 may also be other structures, for example, the pressure relief structure may be a patch welded to the battery case; the pressure relief structure can also be a thinning structure on the battery shell; the pressure relief structure may also be a weak structure of the battery case itself.

In this exemplary embodiment, as shown in fig. 1 to 6, the battery pack may further include a support base plate 7, and the support base plate 7 is located at a side of the bottom plate 2 facing away from the unit cells 1. The supporting base plate 7 may be a metal piece, and the supporting base plate 7 may be formed with a pressure relief channel 6 for pressure relief of the pressure relief structure 11.

In this exemplary embodiment, as shown in fig. 8 and 9, fig. 8 is a schematic structural view of another exemplary embodiment of the battery pack of the present disclosure, and fig. 9 is a schematic structural view of a bottom plate in the battery pack shown in fig. 8.

In the present exemplary embodiment, an opening 233 is disposed at the bottom of the first groove 23, and the opening 233 and the pressure relief structure 11 are disposed opposite to each other. The high pressure gas discharged from the pressure release structure 11 can be transmitted into the preset pressure release channel 6 through the opening 233.

In this exemplary embodiment, the cylindrical battery may be a wound battery, that is, a first pole piece, a second pole piece opposite to the first pole piece, and a diaphragm sheet disposed between the first pole piece and the second pole piece are wound to obtain a wound battery cell.

The unit cell is a minimum unit that includes a battery cell and an electrolyte and is capable of performing an electrochemical reaction such as charge/discharge. The battery cell refers to a unit formed by winding or laminating a stacked portion, wherein the stacked portion comprises a first pole piece, a separator and a second pole piece. When the first pole piece is a positive pole piece, the second pole piece is a negative pole piece. Wherein the polarities of the first pole piece and the second pole piece can be interchanged. The first and second pole pieces are coated with an active substance.

It should be understood that in other exemplary embodiments, the unit cell may also be a prismatic cell, that is, the cell may be a quadrangular cell, where the quadrangular cell mainly refers to a prismatic shape, but it is not strictly limited whether each side of the prism is necessarily a strictly straight line, and the corners between sides are not necessarily right angles, and may be arc transitions.

The single battery can also be a laminated battery, the laminated battery is convenient to group, and the battery with longer length can be obtained by processing. Specifically, the battery cell is a laminated battery cell, and the battery cell is provided with a first pole piece, a second pole piece opposite to the first pole piece and a diaphragm sheet arranged between the first pole piece and the second pole piece, which are mutually laminated, so that a plurality of pairs of the first pole piece and the second pole piece are stacked to form the laminated battery cell.

In the present exemplary embodiment, the battery pack may be a battery module or a battery pack.

The battery module comprises a plurality of single batteries, the single batteries can be square batteries, the battery module can further comprise an end plate and a side plate, and the end plate and the side plate are used for fixing the plurality of batteries. The single battery can be a cylindrical battery, and the cylindrical battery can be arranged on the supporting plate to form the battery module.

The battery pack comprises a plurality of batteries and a box body, wherein the box body is used for fixing the plurality of single batteries.

It should be noted that the battery pack includes a plurality of unit batteries, and the plurality of unit batteries are disposed in the case. Wherein, a plurality of battery cells can be installed in the box after forming the battery module. Or, a plurality of single batteries can be directly arranged in the box body, namely, the plurality of single batteries do not need to be grouped, and the plurality of single batteries are fixed by the box body.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

The drawings in the present disclosure relate only to the structures to which the present disclosure relates, and other structures may be referred to in general. The embodiments of the present disclosure and features in the embodiments may be combined with each other to arrive at a new embodiment without conflict. It will be understood by those skilled in the art that various modifications and equivalent substitutions may be made to the disclosed embodiments without departing from the spirit and scope of the disclosed embodiments, which are intended to be encompassed within the scope of the appended claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (13)

1. A battery pack, the battery pack comprising:

a plurality of single cells (1), wherein the single cells (1) comprise pressure release structures (11) positioned on the side surfaces of the single cells;

the bottom support plate (2) is supported on the side surface of the single battery (1) where the pressure relief structure (11) is arranged, the bottom support plate (2) comprises a plurality of protruding parts (21) facing one side of the single battery (1), a first groove (23) is formed between the protruding parts (21), and a second groove (22) is formed on one side of the protruding parts (21) away from the single battery (1);

the single battery (1) is supported on the protruding portion (21), and the pressure release structure (11) of the single battery (1) and the first groove (23) are oppositely arranged.

2. The battery pack according to claim 1, wherein a plurality of the protruding portions (21) extend in a first direction (X) and are spaced apart in a second direction (Y), the first direction (X) and the second direction (Y) intersecting;

the single battery (1) is supported on two adjacent protruding parts (21) in the second direction (Y), and a pressure release structure (11) of the single battery (1) and a first groove (23) between the two protruding parts (21) for supporting the single battery (1) are oppositely arranged.

3. The battery pack according to claim 2, wherein the second groove (22) formed on the side of the protruding portion (21) facing away from the unit cell (1) extends in the extending direction of the protruding portion (21).

4. The battery pack according to claim 2, wherein a plurality of the unit cells (1) are distributed in the first direction (X) and the second direction (Y) array;

a plurality of the single cells (1) distributed in the first direction (X) are supported on the same group of adjacent protruding parts (21).

5. The battery pack according to claim 4, wherein a plurality of unit cells (1) distributed in the first direction (X) form a unit cell row (1X), at least a part of the protruding portions (21) being supported under two adjacent rows of the unit cells (1X) in the second direction (Y).

6. The battery pack according to claim 2, wherein the first recess (23) comprises:

the plurality of main body grooves (231) are distributed at intervals along the first direction (X), the main body grooves (231) are arranged in one-to-one correspondence with the single batteries (1), and the main body grooves (231) are arranged opposite to the pressure release structures (11) of the corresponding single batteries (1);

a plurality of connection grooves (232), the connection grooves (232) being connected between adjacent ones of the main body grooves (231) in the first direction (X);

wherein the dimension of the main body groove (231) in the second direction (Y) is larger than the dimension of the connection groove (232) in the second direction (Y).

7. The battery pack according to claim 6, wherein the dimension of the main body groove (231) in the second direction (Y) gradually decreases from a center position of the main body groove (231) in the first direction (X) to both sides away from the center position;

a plurality of main body grooves (231) distributed in the first direction (X) form main body groove rows (231X), and the main body grooves (231) are sequentially staggered in the first direction (X) in the adjacent main body groove rows (231X).

8. The battery according to claim 5, characterized in that the bottom plate (2) comprises a plurality of sub bottom plates (5), a plurality of the sub bottom plates (5) extending in a first direction (X) and being distributed along a second direction (Y);

the sub-bottom supporting plates (5) are arranged corresponding to at least one single battery row (1 x), and the sub-bottom supporting plates (5) are used for supporting the single battery row (1 x) corresponding to the sub-bottom supporting plates.

9. The battery pack according to claim 8, wherein adjacent sub-bottom trays (5) are arranged at intervals;

or, adjacent sub-bottom plates (5) are arranged in contact.

10. The battery pack according to claim 8, wherein the sub-bottom plates (5) include sub-protrusions (211) near their edges in the second direction (Y), and in the sub-bottom plates (5) adjacent in the second direction (Y), adjacent two of the sub-protrusions (211) are spliced to form the protrusion (21).

11. Battery according to any of claims 1-10, characterized in that the bottom plate (2) is a blister.

12. Battery according to any of claims 1-10, characterized in that the bottom of the first recess (23) is provided with an opening (233), the opening (233) and the pressure relief structure (11) being arranged opposite.

13. Battery pack according to any of claims 1-10, wherein the unit cells (1) are cylindrical cells.