CN113782901B

CN113782901B - Battery pack and electric vehicle

Info

Publication number: CN113782901B
Application number: CN202010443582.6A
Authority: CN
Inventors: 胡世超; 彭青波; 王晓鹏; 朱建华; 鲁志佩; 孙华军
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2023-12-12
Anticipated expiration: 2040-05-22
Also published as: CN113782901A

Abstract

The application provides a battery pack and an electric vehicle, wherein the battery pack comprises a box body and a plurality of electrode core strings which are positioned in the box body and are electrically connected with each other, the box body comprises at least one sub-box body, the at least one sub-box body is connected with a box body forming the box body, an opening is formed in the end part of the box body along a second direction, the box body further comprises end plates for sealing the opening, each opening corresponds to at least one end plate, the sub-box body comprises at least one structural beam and a top plate and a bottom plate which are oppositely arranged along a first direction, the interior of the box body is divided into a plurality of accommodating cavities by at least one structural beam, and at least one electrode core string is arranged in each accommodating cavity.

Description

Battery pack and electric vehicle

Technical Field

The application relates to the field of batteries, in particular to a battery pack and an electric vehicle.

Background

The power battery, namely a battery pack, is a device for providing power for a new energy automobile, the traditional battery pack comprises a box body and a battery module arranged in the box body, the box body of the battery pack comprises a tray and an upper cover connected with the tray, the battery module is fixed on the tray, when the battery pack is assembled, a plurality of batteries are generally arranged in sequence to form a battery pack, then, two ends of the battery pack in the length direction are provided with integrated end plates, two sides of the battery pack in the width direction are provided with side plates, and the end plates and the side plates are fixedly connected through bolts or pull rods or welding to form the battery module; and finally, the battery module is installed in the tray through fasteners such as bolts.

Above-mentioned battery package adopts the design of integral type end plate, when the inside part of battery package breaks down, need dismantle whole end plate, just can detect maintenance and change, because the end plate is inseparable with the connection of battery package body, therefore the dismantlement of end plate is more difficult, when the trouble of a certain part of battery package, dismantle whole end plate, the part that does not break down also will expose, inevitably appear various collisions or the foreign matter gets into and leads to the part that does not break down originally in the battery package to also can appear new trouble in the maintenance process, and multiple dismantlement and installation can lead to end plate and battery package body coupling not closely moreover, the new safety problem of easily initiating.

Disclosure of Invention

The present application is directed to at least one of the technical problems of the prior art, and therefore, in one aspect, the present application provides a battery pack, including a case and a plurality of electrode core strings electrically connected to each other inside the case;

the box body comprises at least one sub-box body, wherein the at least one sub-box body is connected with a box body forming the box body, an opening is formed in at least one end part of the sub-box body along a second direction, the box body further comprises an end plate for closing the opening, and the second direction is the width direction of the box body or the second direction is the length direction of the box body;

Wherein each opening corresponds to a plurality of end plates when the case includes one sub-case, and corresponds to at least one end plate when the case includes a plurality of sub-cases;

the sub-box body comprises at least one structural beam, a top plate and a bottom plate, wherein the top plate and the bottom plate are oppositely arranged along a first direction, the first direction is the height direction of the box body, the structural beam is positioned between the top plate and the bottom plate, at least one structural beam is connected with the top plate and the bottom plate, the interior of the box body is divided into a plurality of accommodating cavities by the at least one structural beam, and at least one pole core string is arranged in the accommodating cavity;

the pole core string comprises a plurality of pole core groups which are sequentially arranged along the second direction and connected in series; the pole core group is encapsulated in the encapsulation film; the length direction of the pole core string extends along a second direction; the second direction is the width direction of the box body or the second direction is the length direction of the box body;

the box body is provided with an installation part which is used for being connected and fixed with an external load.

In another aspect, the application provides an electric vehicle, which comprises a vehicle body and the battery pack, wherein the battery pack is fixed on the vehicle body through the mounting part.

The application has the beneficial effects that: the battery pack comprises at least one sub-box body and a plurality of end plates, the number of the sub-box bodies and the end plates can be selected according to actual demands, the at least one sub-box body is connected to form the box body, at least one end part of each sub-box body along the second direction is provided with an opening, the end plates are used for sealing the opening, each opening corresponds to at least one end plate, so that the flexibility and the universality of the battery pack design are improved, the later disassembly and maintenance are convenient, when a problem occurs in a certain area in the later battery pack, the position of the area with the problem can be judged through external detection, and then the end plates of the corresponding area are disassembled, so that the inside of the battery pack is maintained and replaced, more parts are prevented from being disassembled, more parts in the battery pack are prevented from being exposed to the outside, and the safety of maintenance and replacement is improved. In addition, the pole core groups are packaged in the packaging film, the pole core groups are connected in series to form a pole core string, and the pole core string is arranged in the box body of the battery pack, so that double-layer sealing is realized through the packaging film and the box body of the battery pack, and the sealing effect is improved; in addition, the pole core string adopted by the application omits the fixing structure (such as an end plate, a side plate, a fastener and the like) of the battery box body and the battery module in the prior art, thereby improving the space utilization rate of the battery pack, reducing the weight of the battery pack and improving the energy density of the battery pack.

Drawings

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

Fig. 1 is a schematic structural diagram of a battery pack according to an embodiment of the present application;

fig. 2 is an exploded view of a battery pack according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a case according to an embodiment of the present application;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

FIG. 5 is an exploded view of a case according to an embodiment of the present application;

fig. 6 is an exploded view showing a part of the structure of a battery pack according to an embodiment of the present application;

fig. 7 is an exploded view showing a part of the structure of another battery pack according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a pole string according to an embodiment of the present application;

FIG. 9 is a schematic diagram of a connection structure between a pole core set and a fixed spacer ring according to an embodiment of the present application;

FIG. 10 is an exploded view of FIG. 9;

FIG. 11 is a schematic diagram of a serial connection of two pole core strings in the same accommodating cavity according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a series connection of two pole core strings in the same housing cavity according to another embodiment of the present application;

FIG. 13 is a schematic diagram of a structure of two pole pieces connected in series and parallel in the same accommodating cavity according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of two pole core strings connected in series in two accommodating cavities according to an embodiment of the present application;

FIG. 15 is a schematic diagram of a serial-parallel connection structure of two pole pieces in two accommodating cavities according to an embodiment of the present application;

FIG. 16 is a schematic diagram of a series connection of two pole strings in two receiving cavities according to another embodiment of the present application;

FIG. 17 is a schematic diagram of two pole pieces connected in series and parallel in two receiving cavities according to another embodiment of the present application;

FIG. 18 is a schematic diagram of a package film package electrode core set according to an embodiment of the present application;

fig. 19 is a schematic structural diagram of a packaging film packaging pole piece group according to another embodiment of the present application;

fig. 20 is a schematic structural diagram of a second explosion-proof valve according to an embodiment of the present application.

Reference numerals:

10. a battery pack;

100. a case; 101. a sub-box; 102. a top plate; 103. a bottom plate; 104. a mounting part; 105. a mounting hole; 106. a first side rail; 107. a second side rail; 108. a partition plate; 109. a connecting plate; 110. an opening; 111. an end plate; 112. a glue injection hole; 113. a case body;

200. a structural beam;

300. a receiving chamber;

400. a pole core group; 401. a pole core string; 410. a first electrode lead-out member; 420. a second electrode lead-out member; 430. a pole core group main body; 440. a first conductive member; 450. fixing the spacer ring; 451. a plug pin; 452. a jack; 453. a first spacer; 454. a second spacer ring; 460. a second conductive member;

500. packaging films; 510. a packaging part;

600. an insulating support;

700. an insulating protective cover;

800. a second explosion-proof valve; 801. a boss; 802. a cover body; 803. a weakened area; 804. a first explosion-proof valve;

900. and a liquid cooling piece.

Detailed Description

The following description is of the preferred embodiments of the present application, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the principle of the application, and these modifications and variations are also regarded as the scope of the application.

In the description of the present application, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature, and in the description of the application, "a plurality" means two or more, unless otherwise specifically and clearly defined.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate medium, and may be the communication between two elements or the interaction relationship between the two elements, so that those skilled in the art will understand the specific meaning of the terms in the present application according to the specific circumstances.

Referring to fig. 1 to 4, a first embodiment of the present application provides a battery pack 10, which includes a case 100 and a plurality of electrode core strings 401 electrically connected to each other inside the case 100. The case 100 is provided with a mounting portion 104, and the mounting portion 104 is connected and fixed to an external load. The box body 100 comprises at least one sub box body 101, the at least one sub box body 101 is connected to form a box body 113 of the box body 100, at least one end of the sub box body 101 along the second direction is provided with an opening 110, and the box body 100 further comprises an end plate 111 for closing the opening 110; wherein, when the case 100 includes one sub-case 101, each opening 110 corresponds to a plurality of end plates 111, that is, when the case 100 includes only one sub-case 101, the opening 110 at each end of the sub-case 101 is closed by a plurality of end plates 111; when the case 100 includes a plurality of sub-cases 101, each opening 110 corresponds to at least one of the end plates 111, that is, when there are a plurality of sub-cases 101, it may be that each opening of each sub-case 101 is correspondingly closed by using one end plate 111, and in this case, for the whole case 100, the end plate 111 at the agreeing end in the second direction has a plurality of end plates, and when the components inside one of the sub-cases 101 need to be maintained, only the end plate corresponding to the sub-case 101 needs to be disassembled, it may be understood that when there are a plurality of sub-cases 101, each opening 110 of each sub-case may be closed by using a plurality of end plates 111.

The sub-tank 101 comprises at least one structural beam 200 and a top plate 102 and a bottom plate 103 which are oppositely arranged along a first direction, the structural beam 200 is positioned between the top plate 102 and the bottom plate 103, at least one structural beam 200 is connected with the top plate 102 and the bottom plate 103, at least one structural beam 200 divides the interior of the sub-tank 101 into a plurality of accommodating cavities 300, and at least one pole core string 401 is arranged in at least one accommodating cavity 300; the pole core string 401 includes a plurality of pole core groups 400 sequentially arranged along the second direction and connected in series, the core groups 400 are encapsulated in the encapsulation mold 500, and the length of the pole core string 401 extends along the second direction; the first direction is a height direction of the case 100, and the second direction is a length direction of the case 100 or a width direction of the case 100.

Traditional battery package adopts the design of integral type end plate, when the inside part of battery package breaks down, need dismantle whole end plate, just can detect maintenance and change, need spend the dismouting of more time.

The case 100 of the battery pack 10 of the present application includes at least one sub-case 101, at least one sub-case 101 is connected to form a case body 113, at least one end of the sub-case 101 along the second direction is provided with an opening 110, the case 100 further includes an end plate 111, each sub-case 101 corresponds to at least one end plate 111, i.e., each end plate 111 corresponds to a portion of the case body 113, when a certain area in the battery pack 10 fails, the area where the failure occurs is determined by external detection, then the end plate 111 corresponding to the area is removed, without removing all the end plates 11, so that the removal time is saved, and simultaneously, other areas of the battery pack which do not fail are also prevented from being exposed to the outside, the safety in the process of removal and maintenance is ensured, and the design flexibility and versatility of the battery pack 10 can be increased by the structure of the plurality of sub-cases 101, thus being beneficial to the standardization, modularization and mass production of the battery pack 10, and the structural beam 200 is positioned between the top plate 102 and the bottom plate 103, and the structural beam 200 is connected with the top plate 102 and the bottom plate 103, so that the structural beam 200, the top plate 102 and the bottom plate 103 form an I-shaped structure, the structure has higher strength and rigidity, the box body 100 of the battery pack 10 has better bearing, impact resistance, extrusion resistance and other performances, and the structural strength of the battery pack 10 can be used as a part of the structural strength of the whole vehicle when the battery pack 10 is installed on the whole vehicle, and the design and the manufacturing cost of the whole vehicle are reduced, in addition, the pole core group 400 is packaged in the packaging die 500, a plurality of pole core groups 400 are connected in series to form a pole core string 401, and the pole core string 401 is arranged in the box body 100 of the battery pack 10, to achieve double-layer sealing through the sealing mold 500 and the case 100 of the battery pack 10, which is advantageous in improving the sealing effect.

In some embodiments, the end plates 111 at the same end of the case 100 in the second direction may be connected together, for example, by bonding, welding, or screwing.

In the present application, the pole core group 400 includes at least one pole core, and when the pole core group 400 includes more than two pole cores, the pole cores are connected in parallel.

The pole piece mentioned in the present application is a pole piece commonly used in the field of power batteries, and the pole piece group 400 are part of the battery and cannot be understood as the battery itself; in addition, the pole core can be a pole core formed by winding or a pole core manufactured in a lamination mode; in general, the electrode core includes at least a positive electrode sheet, a separator, and a negative electrode sheet.

In addition, the structural beam 200 is connected to the top plate 102 and the bottom plate 103, and it is understood that the structural beam 200 is integrally formed with the top plate 102 and the bottom plate 103; alternatively, the structural beam 200, the top plate 102 and the bottom plate 103 are separately formed and then connected by direct or indirect connection, which is not particularly limited. The direct connection may be that one end of the structural beam 200 is connected to the bottom plate 103 and the opposite end of the structural beam 200 is connected to the top plate 102, for example, one end of the structural beam 200 may be welded to the bottom plate 103 and then the opposite end of the structural beam 200 may be welded to the top plate 102. The indirect connection may be where one end of the structural beam 200 is connected to the bottom plate 103 via an intermediate plate and the opposite end of the structural beam 200 is connected to the top plate 102 via an intermediate plate.

In some embodiments, at least one structural beam 200 is joined to the top plate 102 and the bottom plate 103. It can be understood that the top plate 102, the bottom plate 103 and the structural beam 200 are integrally formed; alternatively, one of the top plate 102 and the bottom plate 103 is integrally formed with the structural beam 200, and the other is welded to the structural beam 200; alternatively, one end of the structural beam 200 is welded to the bottom plate 103 and the opposite end of the structural beam 200 is welded to the top plate 102.

It should be noted that, the plurality of pole core strings 401 are electrically connected to each other, and the pole core strings 401 in the two adjacent accommodating cavities 300 may be connected in series or in parallel; alternatively, the pole piece strings 401 in the two accommodating chambers 300 may be connected in series or in parallel; three or more pole piece strings 401 in the housing cavity 300 may be connected in series or in parallel.

In addition, the number of pole core strings 401 in each accommodating cavity 300 and the number of pole core groups 400 contained in each pole core string 401 can be designed according to different electric quantity requirements. Also, the number of pole core strings 401 within each receiving cavity 300 may be the same or different. When a plurality of pole core strings 401 are disposed in the accommodating cavity 300, the pole core strings 401 may be connected in series, parallel or series-parallel.

In addition, the case 100 of the battery pack 10 of the present application is provided with the mounting portion 104, and the case 100 of the battery pack 10 is detachably or non-detachably connected and fixed to an external load by the mounting portion 104 provided thereon. Generally, the case 100 of the battery pack 10 needs to be connected and fixed to an external load, and thus has special requirements for impact resistance, extrusion resistance, and the like, and thus cannot be simply equivalent to the case 100 of the battery module or the unit cell. Generally, the battery pack 10 further includes at least one of a Battery Management System (BMS), a battery connector, a battery sampler, and a battery thermal management system.

In an embodiment, as shown in fig. 1 to 3, the box 100 includes a sub-box 101, at least one end of the sub-box 101 along the second direction is provided with an opening 110, and the opening 110 corresponds to a plurality of end plates 111.

In an embodiment, as shown in fig. 2 to 4, the case 100 includes a plurality of sub-cases 101, and openings 110 are formed at least one end of the sub-cases 101 along the second direction, and each opening 110 corresponds to one of the end plates 111.

In an embodiment, the case 100 includes a plurality of sub-cases 101, and openings 110 are formed at least one end of the sub-cases 101 along the second direction, and each opening 110 corresponds to a plurality of end plates 111.

In an embodiment, the two ends of the sub-housing 101 along the second direction are provided with openings 110, and the openings 110 are sealed by the end plates 11, it is understood that when the two ends of the sub-housing 101 along the second direction are provided with the openings 110, the first electrode and the second electrode (i.e., the positive electrode and the negative electrode) of the core string 401 located in the accommodating cavity 300 may be led out from the two openings 110, respectively.

Alternatively, the connection between the end plate 111 and the opening 110 may be a detachable connection such as screwing, riveting, or may be a connection such as welding, bonding, or the like, but the tightness between the end plate 111 and the sub-tank 101 needs to be ensured.

In one embodiment, the case 100 includes a first explosion-proof valve 804, and the first explosion-proof valve 804 is disposed on the end plate 111, so designed as to prevent the pressure in the second direction in the battery pack 10 from exceeding a preset value

In an embodiment, the end plate 111 is hollow, and the end plate 111 is provided with reinforcing ribs, so that not only is the material saved and the overall weight of the battery pack 10 reduced, but also the structural strength of the end part of the battery pack 10 along the second direction is improved, and the stability of the electrode core inside the battery pack 10 is ensured.

In an embodiment, as shown in fig. 1 to 3, the case 100 further includes a first side beam 106 and a second side beam 107 distributed on opposite sides of the case body 113 along a third direction, the second direction being a length direction of the case 100, and the third direction being a width direction of the case 100; alternatively, the second direction is the width direction of the case 100, and the third direction is the length direction of the case 100.

In an embodiment, as shown in fig. 3 to 5, a plurality of sub-boxes 101 are sequentially arranged along a third direction, the sub-boxes 101 located at two ends of the third direction in the plurality of sub-boxes 101 are end sub-boxes, one of the two end sub-boxes is connected with a first side beam 106, and the other is connected with a second side beam 107. The first sub-tank 101 and the last sub-tank 101 in the Y direction in fig. 5 are end sub-tanks, respectively.

Further, the end sub-tank connected to the first side rail 106 is integrally formed with the first side rail 106, and the end sub-tank connected to the second side rail 107 is integrally formed with the second side rail 107. Thus, the processing technology can be simplified, the cost can be reduced, and the structure strength can be ensured.

Specifically, at least one of the top plate 102 and the bottom plate 103 of the end sub-tank connected to the first side rail 106 is integrally formed with the first side rail 106, and at least one of the top plate 102 and the bottom plate 103 of the end sub-tank connected to the second side rail 107 is integrally formed with the second side rail 107. For example, the integral aluminum profile is extruded.

However, in other embodiments, the end sub-tank connected to the first side rail 106 and the first side rail 106 are integrally formed, and the end sub-tank connected to the second side rail 107 and the second side rail 107 are connected by direct or indirect means. Alternatively, the end sub-tank connected to the second side rail 107 and the second side rail 107 are integrally formed, and the end sub-tank connected to the first side rail 106 and the first side rail 106 are connected by direct or indirect means.

In one embodiment, as shown in fig. 3 to 5, the first side beam 106 and the second side beam 107 have cavities therein, and a partition 108 is disposed in the cavities, and the partition 108 divides the cavities into a plurality of subchambers. By this arrangement, the first side rail 106 and the second side rail 107 can be ensured to have a certain structural strength, thereby being advantageous to improve the impact and compression resistance strength of the battery pack 10. However, in other embodiments, either the first side rail 106 or the second side rail 107 has a cavity inside.

In one embodiment, as shown in fig. 3 to 5, the case body 113 further includes a connection plate 109, and the connection plate 109 is connected between two adjacent sub-cases 101. The connection mode is not particularly limited in the application, and can be detachable connection, such as bolt connection, riveting and the like; or a non-detachable connection such as welding, adhesive, etc.

In one embodiment, the connection plate 109 has a cavity therein, and a partition 108 is disposed in the cavity, and the partition 108 divides the cavity into a plurality of subchambers. By this arrangement, the structural strength of the connection plate 109 can be increased, and the connection reliability of the two sub-housings 101 can be improved.

In one embodiment, as shown in fig. 3 to 5, a plurality of structural beams 200 are disposed in the sub-tank 101, the plurality of structural beams 200 are spaced apart along a third direction, the length of each structural beam 200 extends along a second direction, and each structural beam 200 is connected to the top plate 102 and the bottom plate 103, and the third direction is different from the first direction and the second direction. In this embodiment, a plurality of structural beams 200 are provided in each sub-tank 101. Of course, in other embodiments, a plurality of structural beams 200 may be disposed in the partial tank 101 according to actual needs.

In the present application, the first direction is the height of the case 100, the second direction is the width direction of the case 100, and the third direction is the length direction of the case 100; alternatively, the second direction is a longitudinal direction of the case 100, and the third direction is a width direction of the case 100. The first direction is X direction in the figure, the second direction is Z direction in the figure, and the third direction is Y direction in the figure.

However, in other embodiments, any two of the first direction, the second direction, and the third direction may be disposed at other angles, for example, 80 ° or 85 °, which is not particularly limited to the present application.

It should be noted that, the structural beam 200 is connected to the top plate 102 and the bottom plate 103, and it is understood that the structural beam 200 is integrally formed with the top plate 102 and the bottom plate 103; alternatively, the structural beam 200, the top plate 102 and the bottom plate 103 are separately formed and then connected by direct or indirect connection, which is not particularly limited.

In some embodiments, at least one of the top plate 102 and the bottom plate 103 is integrally formed with the structural beam 200. The arrangement is simple in processing technology, is beneficial to reducing production cost, and can ensure that the box body 100 has enough structural strength and rigidity so as to meet the requirements of the box body 100 on the performances of bearing, impact resistance, extrusion resistance and the like.

Specifically, the top plate 102, the bottom plate 103, and the structural beam 200 are integrally formed. For example, an integral aluminum profile extrusion may be used. In another embodiment, the bottom plate 103 is integrally formed with the structural beam 200, and then the top plate 102 is welded to the structural beam 200. Alternatively, the top plate 102 is integrally formed with the structural beam 200, and then the bottom plate 103 is welded to the structural beam 200.

It can be appreciated that when each structural beam 200 is connected to the top plate 102 and the bottom plate 103, each structural beam 200, the top plate 102 and the bottom plate 103 form an "i" structure, so that the overall case 100 of the battery pack 10 is in a honeycomb structure, and the structure has high strength and rigidity, thereby meeting the requirements of the case 100 for bearing, impact resistance, extrusion resistance and the like. Moreover, the structure of the case 100 is relatively simple and space utilization is high. When the battery pack 10 is mounted on the whole vehicle, the structural strength of the battery pack 10 can be used as a part of the structural strength of the whole vehicle, so that the structural strength of the whole vehicle can be improved, the design requirement of the light weight of the whole vehicle of the electric vehicle can be met, and the design and manufacturing cost of the whole vehicle can be reduced.

In a further embodiment, the first side beam 106 and the second side beam 107 are provided with mounting portions 104, and the mounting portions 104 are adapted to be connected and fixed to an external load.

Of course, in other embodiments, the mounting portion 104 may be disposed on the top plate 102 or the bottom plate 103.

In one embodiment, as shown in fig. 1 and 2, the mounting portion 104 is a mounting hole 105 provided on the first side rail 106 and the second side rail 107. The mounting holes 105 are provided for fasteners (e.g., bolts or rivets) to attach and secure the battery pack 10 to an external load.

Specifically, the mounting hole 105 provided on the first side rail 106 penetrates the first side rail 106 in the first direction, and the mounting hole 105 provided on the second side rail 107 penetrates the second side rail 107 in the first direction. However, the axial direction of the mounting hole 105 may also be arranged at an angle to the first direction, for example 5 ° or 10 °.

Further, the mounting holes 105 are provided in plurality, and the mounting holes 105 provided on the first side rail 106 are sequentially arranged along the length direction of the first side rail 106. Wherein, the length direction of the first side beam 106 is parallel to the second direction.

Also, the mounting holes 105 provided on the second side rail 107 are sequentially arranged along the length direction of the second side rail 107. Wherein, the length direction of the second side beam 107 is parallel to the second direction.

Of course, in another embodiment, the mounting portion 104 is a suspension ring provided on the first side rail 106 and the second side rail 107. The hanging ring is fixedly connected with an external load to fixedly connect the battery pack 10 to the external load.

However, in another embodiment, the mounting portion 104 is a mounting block provided on the first side rail 106 and the second side rail 107, and the mounting block may be fixed to an external load by welding. Of course, the mounting block may also be secured to the external load by gluing or clamping.

In an embodiment, the length of the receiving cavity 300 in the second direction is greater than 500mm, and further, the length of the receiving cavity 300 in the second direction is 500mm-2500mm. By such design, the length of the pole core string 401 arranged in the accommodating cavity 300 can be longer, so that more pole core groups 400 can be accommodated, and the battery pack 10 can meet the requirements of larger capacity and higher space utilization.

Further, the length of the receiving chamber 300 in the second direction is 1000mm to 2000mm.

Further, the length of the receiving chamber 300 in the second direction is 1300mm to 2200mm.

In some embodiments, as shown in fig. 2, 6 and 7, the sub-tank 101 has a first end and a second end opposite in a second direction, and at least one of the first end and the second end of the sub-tank 101 is provided with an opening 110; the case 100 further includes end plates 111 closing the openings 110, each opening 110 corresponding to at least one end plate 111. So arranged, only the end plate 111 corresponding to the opening 110 of the sub-tank 101 needs to be removed when replacing or overhauling, thereby simplifying the operation.

It will be appreciated that the pole core string 401 may be mounted in the accommodating cavity 300 through the opening 110 of the sub-housing 101, which is relatively convenient to operate, and at the same time, ensures a high structural strength of the sub-housing 101.

In some embodiments, as shown in fig. 2, 6 and 7, the battery pack 10 further includes a plurality of insulating holders 600, the insulating holders 600 being positioned inside the end plates 111, and the insulating holders 600 being provided at the opening 110 of at least one of the first and second ends of the sub-case 101. The two pole core groups 400 located at the same side and adjacent to the opening 110 of the sub-tank 101 in the adjacent two accommodation chambers 300 are electrically connected by the first conductive member 440, and the first conductive member 440 is fixed to the insulating bracket 600. Thus, when overhauling or replacing, only the insulating bracket 600 corresponding to the sub-housing 101 needs to be removed, thereby simplifying the operation. Also, each of the insulating holders 600 may serve as a fixed support and insulation for the first conductive member 440 disposed thereon.

In the present embodiment, an insulating holder 600 is provided at the opening 110 of the first end or the second end of each sub-tank 101.

The inside of the end plate 111 is understood to mean the side of the end plate 111 adjacent to the pole core group 400. The first conductive member 440 is a connecting piece, but it can be other shapes, such as a pillar shape.

In a further embodiment, as shown in fig. 3 and 6, a plurality of insulating holders 600 located at the same end of the case body 113 in the second direction are integrally formed. That is, the plurality of insulating holders 600 at the first end of the case body 113 are integrally formed, and/or the plurality of insulating holders 600 at the second end of the case body 1133 are integrally formed. By such arrangement, the processing of the insulating bracket 600 can be simplified, which is beneficial to saving the cost.

In some embodiments, the first conductive member 440 is disposed on a side of the insulating support 600 facing away from the pole core group 400, and the pole core group 400 includes a first electrode lead-out part 410 and a second electrode lead-out part 420 for leading out current, and the first electrode lead-out part 410 and the second electrode lead-out part 420 are distributed on opposite sides of the pole core group 400 along the second direction; the first electrode lead-out member 410 of one of the two electrode core groups 400 located at the same side and adjacent to the opening 110 in the adjacent two accommodating chambers 300 penetrates the insulating holder 600 and the first conductive member 440 and is electrically connected through the first conductive member 440 to the first electrode lead-out member 410 of the other electrode core group 400, so that the parallel connection of the electrode core groups 400 of the adjacent two accommodating chambers 300 is realized, and the connection path of the connection manner is relatively short, which is beneficial to reducing the internal resistance.

In other embodiments, the second electrode lead-out member 420 of one pole core group 400 of the two pole core groups 400 located on the same side and adjacent to the opening 110 in the two adjacent accommodating chambers 300 is electrically connected with the second electrode lead-out member 420 of the other pole core group 400 through the insulating support 600 and the first conductive member 440 and through the first conductive member 440, so as to realize parallel connection of the pole core groups 400 of the two adjacent accommodating chambers 300, and the connection path of the connection manner is relatively short, which is beneficial to reduce the internal resistance.

In other embodiments, the first electrode lead-out member 410 of one of the two electrode core groups 400 located on the same side and adjacent to the opening 110 in the adjacent two accommodating chambers 300 is electrically connected to the second electrode lead-out member 420 of the other electrode core group 400 through the insulating support 600 and the first conductive member 440 and through the first conductive member 440, so as to realize the series connection of the electrode core groups 400 of the adjacent two accommodating chambers 300, and the connection path of the connection manner is relatively short, which is beneficial to reduce the internal resistance.

In a further embodiment, as shown in fig. 2, 6 and 7, the battery pack 10 further includes a plurality of insulation protection covers 700, and the insulation protection covers 700 are disposed between the insulation support 600 and the end plates 111. The insulation cover 700 may protect the first conductive member 440 fixed on the insulation support 600 to prevent the first conductive member 440 and the connection between the first conductive member 440 and the first electrode lead-out part 410 or the second electrode lead-out part 420 from being damaged, and also prevent the first conductive member 440 from being in contact with other metal members to cause short circuit.

In a further embodiment, as shown in fig. 3 and 6, a plurality of insulation protection covers 700 located at the same end of the case body 113 along the second direction are integrally formed. That is, the plurality of insulation protection caps 700 at the first end of the case body 113 are integrally formed, and/or the plurality of insulation protection caps 700 at the second end of the case body 113 are integrally formed. With this arrangement, the processing of the insulation protection cover 700 can be simplified, which is beneficial to saving the cost.

In one embodiment, as shown in fig. 7, the length of the pole core string 401 is greater than 400mm, and further, the length of the pole core string 401 is 400mm-2500mm. Further, the length of the pole core string 401 is 1000mm-2000 mm. Further, the length of the pole core string 401 is 1300mm-2200mm. It will be appreciated that providing a plurality of pole core groups 400 in series within the receiving cavity 300 to form a pole core string 401 may reduce the internal resistance compared to providing only one pole core group 400 of the same length as the pole core string 401. Because once the pole core group 400 is longer, the length of the copper aluminum foil used as the current collector is correspondingly increased, the internal resistance is greatly improved, the current requirements of higher and higher power and quick charge cannot be met, and the problem can be avoided by adopting the mode of connecting a plurality of pole core groups 400 in series.

Referring to fig. 9 and 10, in a further embodiment, the pole core groups 400 include a first electrode lead-out part 410 and a second electrode lead-out part 420 for leading out current, the first electrode lead-out part 410 and the second electrode lead-out part 420 are distributed on opposite sides of the pole core groups 400 along a second direction, and the first electrode lead-out part 410 of one pole core group 400 of two adjacent pole core groups 400 forming the pole core string 401 is electrically connected with the second electrode lead-out part 420 of the other pole core group 400 so as to connect the two adjacent pole core groups 400 in series. That is, the plurality of pole core groups 400 forming the pole core string 401 are arranged in a head-to-head manner, and the arrangement manner can conveniently realize the serial connection of the pole core groups 400, and the connection structure is simple.

In an embodiment, as shown in fig. 2 to 4, a plurality of pole core strings 401 are disposed in the accommodating cavity 300, and the plurality of pole core strings 401 are sequentially arranged and electrically connected along the thickness direction of the pole core group 400, and the thickness direction of the pole core group 400 is parallel to the third direction. In this way, more pole core strings 401 can be arranged in the accommodating cavity 300 to meet the requirement of actual use.

In the following, a few cases of electrically connecting a plurality of pole core strings 401 in the same housing cavity 300 will be specifically described, but it should be noted that the following description is only illustrative, and embodiments of the present application are not limited thereto:

referring to fig. 11 and 12, in a further embodiment, a plurality of pole strings 401 within the same receiving cavity 300 are connected in series.

A first pole core group 400 of one pole core string 401 of the adjacent two pole core strings 401 is electrically connected with a first pole core group 400 of the other pole core string 401. Alternatively, the last pole core group 400 of one pole core string 401 of the adjacent two pole core strings 401 is electrically connected with the last pole core group 400 of the other pole core string 401. As shown in fig. 11 and 12, the leftmost pole core group 400 in the two pole core strings 401 is the first pole core group 400, and the rightmost pole core group 400 is the last pole core group.

Further, the first electrode lead-out part 410 of the first pole core group 400 of one pole core string 401 of the adjacent two pole core strings 401 is located at the same side as the second electrode lead-out part 420 of the first pole core group 400 of the other pole core string 401 (as shown in fig. 11). Alternatively, the second electrode lead-out member 420 of the last pole core group 400 of one pole core string 401 of the adjacent two pole core strings 401 is located on the same side as the first electrode lead-out member 410 of the last pole core group 400 of the other pole core string 401 (as shown in fig. 12).

The plurality of pole core strings 401 in the same accommodating cavity 300 are connected in series by adopting the connection mode, so that the electric connection path is shorter, and the internal resistance is reduced. In other embodiments, other series connections may be used.

Referring to fig. 13, in a further embodiment, a plurality of pole core strings 401 within the same housing 300 are connected in parallel.

A first pole core group 400 of one pole core string 401 of the adjacent two pole core strings 401 is electrically connected with a first pole core group 400 of the other pole core string 401, and a last pole core group 400 of the one pole core string 401 of the adjacent two pole core strings 401 is electrically connected with a last pole core group 400 of the other pole core string 401. As shown in fig. 13, the leftmost pole core group 400 in the two pole core strings 401 is the first pole core group 400, and the rightmost pole core group 400 is the last pole core group.

Further, the first electrode lead-out part 410 of the first pole core group 400 of one pole core string 401 of the adjacent two pole core strings 401 is located at the same side as the first electrode lead-out part 410 of the first pole core group 400 of the other pole core string 401, and the second electrode lead-out part 420 of the last pole core group 400 of the one pole core string 401 of the adjacent two pole core strings 401 is located at the same side as the second electrode lead-out part 420 of the last pole core group 400 of the other pole core string 401.

The plurality of pole core strings 401 in the same accommodating cavity 300 are connected in parallel by adopting the connection mode, so that the electric connection path is shorter, and the reduction of internal resistance is facilitated. In other embodiments, other parallel connections may be used.

Further, the following describes in detail several cases of electrically connecting the pole core strings 401 of two adjacent receiving cavities 300, it should be noted that the following descriptions are only examples, and embodiments of the present application are not limited thereto:

referring to fig. 14, in a further embodiment, the pole core strings 401 in adjacent two receiving cavities 300 are connected in series.

The first pole core group 400 of one of the pole core strings 401 in one of the adjacent two receiving cavities 300 is electrically connected with the first pole core group 400 of one of the pole core strings 401 in the other receiving cavity 300; alternatively, the last pole core group 400 of one of the pole core strings 401 in one of the adjacent two receiving cavities 300 is electrically connected with the last pole core group 400 of one of the pole core strings 401 in the other receiving cavity 300. In fig. 14, the first pole core group 400 of the pole core string 401 is the leftmost pole core group 400, and the last pole core group 400 of the pole core string 401 is the rightmost pole core group 400. Alternatively, the first pole piece group 400 of the pole piece string 401 is the rightmost pole piece group 400, and the last pole piece group 400 of the pole piece string 401 is the leftmost pole piece group 400. In fig. 14, there is shown a case where three pole-core strings 401 are included in each housing chamber 300, and two pole-core strings 401 in the two housing chambers 300, which are closest in spaced position, are electrically connected; in other embodiments, where 1 or a different number of pole strings 401 is included in the accommodating cavity 300, when a plurality of pole strings 401 is included in the accommodating cavity 300, the first pole string 401 of one accommodating cavity 300 in the third direction may be electrically connected to the second pole string 401 of the other accommodating cavity 300 in the third direction, that is, not the two pole strings 401 closest to each other in the two accommodating cavities 300 may be electrically connected.

In a further embodiment, the first electrode lead-out part 410 of the first one of the pole core strings 401 in one of the adjacent two receiving cavities 300 is located on the same side as the second electrode lead-out part 420 of the first one of the pole core strings 400 in the other receiving cavity 300;

alternatively, the first electrode lead-out member 410 of the last pole core group 400 of one of the pole core strings 401 in one of the adjacent two accommodation chambers 300 is located on the same side as the second electrode lead-out member 420 of the last pole core group 400 of one of the pole core strings 401 in the other accommodation chamber 300.

The series connection between the pole core strings 401 in the adjacent two accommodating chambers 300 by adopting the connection mode can make the path of electrical connection shorter, which is beneficial to reducing the internal resistance. In other embodiments, other series connections may be used.

In some preferred embodiments, two adjacent containment cavities 300 are defined as a first containment cavity 300 and a second containment cavity 300, respectively, with one pole string 401 disposed adjacent to the second containment cavity 300 within the first containment cavity 300 being connected in series with one pole string 401 disposed adjacent to the first containment cavity 300 within the second containment cavity 300.

Further, the first pole core group 400 of one pole core string 401 disposed adjacent to the second receiving cavity 300 in the first receiving cavity 300 is electrically connected with the first pole core group 400 of one pole core string 401 disposed adjacent to the first receiving cavity 300 in the second receiving cavity 300.

Alternatively, the last pole core group 400 of one pole core string 401 disposed adjacent to the second receiving cavity 300 within the first receiving cavity 300 is electrically connected with the last pole core group 400 of one pole core string 401 disposed adjacent to the first receiving cavity 300 within the second receiving cavity 300.

It can be appreciated that the above connection method can make the path of electrical connection shorter, which is beneficial to reduce internal resistance.

Referring to fig. 15, in a further embodiment, the pole core strings 401 in two adjacent receiving cavities 300 are connected in parallel.

Specifically, the first pole core group 400 of one of the pole core strings 401 in one of the adjacent two accommodating chambers 300 is electrically connected with the first pole core group 400 of one of the pole core strings 401 in the other accommodating chamber 300, and the last pole core group 400 of one of the pole core strings 401 in one of the adjacent two accommodating chambers 300 is electrically connected with the last pole core group 400 of one of the pole core strings 401 in the other accommodating chamber 300. In fig. 15, the first pole core group 400 of the pole core string 401 is the leftmost pole core group 400, and the last pole core group 400 of the pole core string 401 is the rightmost pole core group 400. Alternatively, the first pole piece group 400 of the pole piece string 401 is the rightmost pole piece group 400, and the last pole piece group 400 of the pole piece string 401 is the leftmost pole piece group 400.

Further, the first electrode lead-out member 410 of the first pole core group 400 of one of the pole core strings 401 in one of the adjacent two accommodation cavities 300 is located on the same side as the first electrode lead-out member 410 of the first pole core group 400 of one of the pole core strings 401 in the other accommodation cavity 300, and the second electrode lead-out member 420 of the last pole core group 400 of one of the pole core strings 401 in one of the adjacent two accommodation cavities 300 is located on the same side as the second electrode lead-out member 420 of the last pole core group 400 of one of the pole core strings 401 in the other accommodation cavity 300.

The parallel connection between the pole core strings 401 in the adjacent two accommodating chambers 300 by adopting the connection mode can make the electrical connection path shorter, and is beneficial to reducing the internal resistance. In other embodiments, other parallel connections may be used.

Preferably, two adjacent accommodating chambers 300 are defined as a first accommodating chamber 300 and a second accommodating chamber 300, respectively, and one pole piece string 401 disposed adjacent to the second accommodating chamber 300 in the first accommodating chamber 300 is connected in parallel with one pole piece string 401 disposed adjacent to the first accommodating chamber 300 in the second accommodating chamber 300.

Specifically, the first pole core group 400 of one pole core string 401 disposed adjacent to the second accommodating cavity 300 in the first accommodating cavity 300 is electrically connected with the first pole core group 400 of one pole core string 401 disposed adjacent to the first accommodating cavity 300 in the second accommodating cavity 300, and the last pole core group 400 of one pole core string 401 disposed adjacent to the second accommodating cavity 300 in the first accommodating cavity 300 is electrically connected with the last pole core group 400 of one pole core string 401 disposed adjacent to the first accommodating cavity 300 in the second accommodating cavity 300. It can be appreciated that the above connection method can make the path of electrical connection shorter, which is beneficial to reduce internal resistance.

As for each of the accommodating chambers 300, one of the pole core strings 401 is provided, and the pole core strings 401 of two adjacent accommodating chambers 300 are electrically connected in a similar manner to the above manner, only a brief description will be given below:

in some embodiments, as shown in fig. 16, only one pole core string 401 is disposed in the accommodating cavity 300, and the pole core groups 400 in two adjacent accommodating cavities 300 are connected in series in the following manner: a first pole core group 400 of a pole core string 401 in one of the adjacent two receiving cavities 300 is electrically connected to a first pole core group 400 of a pole core string 401 in the other receiving cavity 300; alternatively, the last pole core group 400 of the pole core string 401 in one of the adjacent two receiving cavities 300 is electrically connected with the last pole core group 400 of the pole core string 401 in the other receiving cavity 300. In fig. 16, the first pole core group 400 of the pole core string 401 is the leftmost pole core group 400, and the last pole core group 400 of the pole core string 401 is the rightmost pole core group 400. Alternatively, the first pole piece group 400 of the pole piece string 401 is the rightmost pole piece group 400, and the last pole piece group 400 of the pole piece string 401 is the leftmost pole piece group 400.

In some embodiments, as shown in fig. 17, only one pole core string 401 is disposed in the accommodating cavity 300, where the pole core groups 400 in two adjacent accommodating cavities 300 are connected in parallel in the following manner: a first pole core group 400 of a pole core string 401 in one of the adjacent two receiving cavities 300 is electrically connected to a first pole core group 400 of a pole core string 401 in the other receiving cavity 300, and a last pole core group 400 of a pole core string 401 in one of the adjacent two receiving cavities 300 is electrically connected to a last pole core group 400 of a pole core string 401 in the other receiving cavity 300. In fig. 17, the first pole core group 400 of the pole core string 401 is the leftmost pole core group 400, and the last pole core group 400 of the pole core string 401 is the rightmost pole core group 400. Alternatively, the first pole piece group 400 of the pole piece string 401 is the rightmost pole piece group 400, and the last pole piece group 400 of the pole piece string 401 is the leftmost pole piece group 400.

Referring to fig. 9 and 10 again, in a further embodiment, the pole core assembly 400 includes a pole core assembly main body 430, and a first electrode lead-out component 410 and a second electrode lead-out component 420 for leading out current, wherein the first electrode lead-out component 410 and the second electrode lead-out component 420 are distributed on two opposite sides of the pole core assembly main body 430 along a second direction, and the first electrode lead-out component 410 of one pole core assembly 400 and the second electrode lead-out component 420 of the other pole core assembly 400 in two adjacent pole core assemblies 400 forming the pole core string 401 are electrically connected through a second conductive piece 460;

a fixed spacer 450 is arranged between the pole core group main bodies 430 of the two adjacent pole core groups 400, and the second conductive piece 460 is fixed in the fixed spacer 450; the structure glue is filled between the pole core group main bodies 430 of the adjacent two pole core groups 400 and the fixed space ring 450, so that the plurality of pole core groups 400 can be connected into a whole through the structure glue, thereby improving the structural strength of the pole core string 401 and facilitating the installation of the pole core string 401 in the accommodating cavity 300.

The fixed spacer 450 includes a first spacer 453 and a second spacer 454 which are disposed opposite to each other along a third direction, and the second conductive member 460 is disposed between the first spacer 453 and the second spacer 454, and the first spacer 453 is connected to the second spacer 454 to clamp and fix the second conductive member 460 so as to prevent play between the pole core groups 400.

In this embodiment, a plug 451 is provided on one of the surfaces of the first and second spacers 453 and 454 facing the second conductive member 460, a receptacle 452 is provided on the other of the first and second spacers 453 and 454, and the first and second spacers 453 and 454 are inserted into the receptacle 452 through the plug 451 to be fixedly connected and sandwich the second conductive member 460 therebetween.

Referring to fig. 18, in a further embodiment, a plurality of pole piece groups 400 comprising a pole piece string 401 are encapsulated in an encapsulation film 500; the electrode core set 400 includes a electrode core set main body 430 and a first electrode lead-out part 410 and a second electrode lead-out part 420 for leading out current, and a junction of the first electrode lead-out part 410 of one electrode core set 400 and the second electrode lead-out part 420 of the other electrode core set 400 of the two electrode core sets 400 connected in series is located in the encapsulation film 500; the encapsulation film 500 is formed with an encapsulation part 510 at a position opposite to the first electrode lead-out part 410 and/or the second electrode lead-out part 420 to isolate the adjacent two-pole core pack main body 430.

The packaging part 510 isolates the plurality of pole core groups 400, so that the mutual circulation of electrolyte among the plurality of pole core groups 400 is avoided, the plurality of pole core groups 400 cannot be affected with each other, the electrolyte in the plurality of pole core groups 400 cannot be decomposed due to overlarge potential difference, and the safety and the service life of the battery are ensured.

The package portion 510 may be formed by various embodiments, for example, the package film 500 may be fastened by a tie to form the package portion 510, or the package film 500 may be directly thermally fused to form the package portion 510. The specific manner of the encapsulation portion 510 is not particularly limited.

In the present application, the sealing material used for the preferred packaging film 500 is a PET and PP composite film or an aluminum plastic film. In the present application, it is preferable to pump negative pressure to the cavity inside the packaging film 500 to restrict the pole core group 400, so that there is a requirement of air tightness for the accommodating cavity 300 inside the packaging film 500.

Referring to fig. 19, in other embodiments, each pole piece 400 is encapsulated in an encapsulation film 500 to form pole piece 400 pieces, and the pole piece 400 pieces are connected in series.

In other words, the number of the packaging films 500 corresponds to the number of the pole core groups 400 one by one, each pole core group 400 is individually packaged in one packaging film 500, in this embodiment, after the preparation of a plurality of pole core groups 400 is completed, one packaging film 500 can be individually sleeved outside each pole core group 400, and then the pole core groups 400 are connected in series.

In a further embodiment, the air pressure of the receiving chamber 300 is lower than the air pressure outside the case 100. The vacuum pumping treatment can be performed inside the accommodating cavity 300, so that the air pressure of the accommodating cavity 300 is lower than the air pressure outside the box body 100, after the accommodating cavity 300 is vacuumized, the storage amount of substances such as water vapor, oxygen and the like in the box body 100 can be reduced, the long-time aging effect of the water vapor and the oxygen on the pole core group 400 and each part in the box body 100 is avoided, and the service life of the pole core group 400 or each part inside the box body 100 is prolonged.

In a further embodiment, the casing 100 is provided with an air suction hole. The number of the air extraction holes may be one or more, and may be disposed at a position corresponding to the accommodating cavity 300 of the top plate 102 or the bottom plate 103, or disposed on the first side rail 106 and the second side rail 107.

In a further embodiment, the case 100 is provided with glue injection holes 112 (as shown in fig. 2), each receiving cavity 300 is correspondingly communicated with at least one glue injection hole 112, and the glue injection holes 112 are used for filling glue into the corresponding receiving cavities 300 so as to fixedly connect the pole core groups 400 with the case 100. The electrode core set 400, the box body 100 and the structural beam 200 can be fixedly connected together in a potting mode by using the hollow glass bead filling glue or the structural glue, so that the structural strength of the battery pack 10 is further improved. In the present embodiment, the glue injection hole 112 is provided on the top plate 102 of the sub-tank 101. Of course, in other embodiments, the glue injection holes 112 may also be disposed on the bottom plate 103 of the sub-tank 101.

In a further embodiment, two adjacent pole core groups 400 forming the pole core string 401 are electrically connected through the second conductive member 460, and the glue injection hole 112 is disposed corresponding to the second conductive member 460. By this arrangement, a high connection strength between the pole core groups 400 can be ensured.

In some embodiments, as shown in fig. 2, a second explosion-proof valve 800 is provided on the case 100, and the second explosion-proof valve 800 seals the glue injection hole 112. In this way, the second explosion-proof valve 800 can serve as a sealing cover for sealing the glue injection hole 112, and also can play a role in safety and explosion prevention.

In some embodiments, as shown in fig. 2 and 20, the second explosion proof valve 800 has a weakened area 803; the second explosion-proof valve 800 includes a cover body 802 in sealing connection with the case body 100 and a protrusion portion 801 provided on the cover body 802, the protrusion portion 801 protruding toward a side facing away from the pole core group 400, and a weakened area 803 is formed on an outer peripheral wall of the protrusion portion 801. In this way, when the pole core group 400 in the battery pack 10 works abnormally to cause excessive gas production, the gas pressure will break the weak area 803 of the second explosion-proof valve 800, so that the battery pack 10 can be prevented from safety accidents.

Note that the weakened area 803 may be a groove or a score. Alternatively, the weakened area 803 may have a thickness that is less than the thickness of the rest of the second explosion proof valve 800.

Further, the glue injection hole 112 is provided on the top plate 102, and the cover 802 is connected with the top plate 102 in a sealing manner. The sealing connection is not particularly limited, and for example, the sealing connection may be achieved by welding or gluing.

In an embodiment, the battery pack 10 further includes a plurality of liquid cooling members 900, and the plurality of liquid cooling members 900 are correspondingly disposed on the bottom plates 103 of the plurality of sub-cases 101, so that the pole core groups 400 can be cooled and radiated by disposing the liquid cooling members 900. Further, the plurality of liquid cooling members 900 are integrally formed. The arrangement can simplify the processing technology and reduce the cost.

The application also provides an electric vehicle, which comprises a vehicle body and the battery pack 10, wherein the battery pack 10 is fixed on the vehicle body through the mounting part 104. According to the electric vehicle provided by the application, when the battery pack 10 is installed on the whole vehicle, the structural strength of the battery pack 10 can be used as a part of the structural strength of the whole vehicle, so that the structural strength of the whole vehicle can be improved, and the whole vehicle of the electric vehicle is facilitated to be realized. And the design requirement of light weight is reduced, and the design and manufacturing cost of the whole vehicle is reduced. In addition, the height of the battery pack 10 of the present application is relatively low so that the space at the height of the vehicle is not excessively occupied.

The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A battery pack, characterized in that the battery pack comprises a box body and a plurality of electrode core strings which are positioned in the box body and are electrically connected with each other;

the box body comprises a plurality of sub-box bodies, the plurality of sub-box bodies are connected to form a box body of the box body, the box body further comprises a connecting plate, the connecting plate is connected between two adjacent sub-box bodies, a cavity is formed in the connecting plate, a partition plate is arranged in the cavity, an opening is formed in at least one end of each sub-box body along a second direction, the box body further comprises an end plate for closing the opening, and the second direction is the width direction of the box body or the length direction of the box body;

wherein each opening corresponds to at least one end plate, and a plurality of end plates positioned at the same end of the box body along the second direction are connected;

the sub-box body comprises at least one structural beam, a top plate and a bottom plate, wherein the top plate and the bottom plate are oppositely arranged along a first direction, the first direction is the height direction of the box body, the structural beam is positioned between the top plate and the bottom plate, at least one structural beam is connected with the top plate and the bottom plate, the interior of the sub-box body is divided into a plurality of accommodating cavities by at least one structural beam, and at least one pole core string is arranged in each accommodating cavity;

The pole core string comprises a plurality of pole core groups which are sequentially arranged along the second direction and connected in series; the pole core group is encapsulated in the encapsulation film; the length direction of the pole core string extends along a second direction; the second direction is the width direction of the box body or the second direction is the length direction of the box body, the pole core group comprises a pole core group main body, a first electrode leading-out part and a second electrode leading-out part, the first electrode leading-out part and the second electrode leading-out part are used for leading out current, the first electrode leading-out part and the second electrode leading-out part are distributed on two opposite sides of the pole core group main body along the second direction, and the first electrode leading-out part of one pole core group and the second electrode leading-out part of the other pole core group in two adjacent pole core groups are electrically connected through a first conductive piece; a fixed space ring is arranged between the pole core group main bodies of the two adjacent pole core groups, and the first conductive piece is fixed in the fixed space ring; structural adhesive is filled between the pole core group main bodies of the two adjacent pole core groups and the fixed space ring; the fixed spacer comprises a first spacer ring and a second spacer ring which are oppositely arranged along a third direction, the first conductive piece is positioned between the first spacer ring and the second spacer ring, the first spacer ring is connected with the second spacer ring to clamp and fix the first conductive piece, and the third direction is different from the first direction and the second direction;

2. The battery pack according to claim 1, wherein both ends of the sub-case in the second direction are provided with openings.

3. The battery pack of claim 2, wherein the housing further comprises a first explosion-proof valve disposed on the end plate.

4. The battery pack of claim 1, wherein the end plate has a hollow structure inside, and wherein the end plate has reinforcing ribs inside.

5. The battery pack according to claim 3, further comprising a plurality of insulating supports, wherein the insulating supports are located on the inner side of the end plate, the opening of at least one end of the sub-box body along the second direction is provided with the insulating supports, two adjacent two pole core groups located on the same side in the second direction and adjacent to the opening of the sub-box body in the accommodating cavity are electrically connected through a first conductive member, and the first conductive member is fixed on the insulating supports.

6. The battery pack of claim 2, wherein a plurality of insulating holders at the same end of the case in the second direction are integrally formed.

7. The battery pack of claim 6, further comprising a plurality of insulating protective covers disposed between the insulating supports and the end plates.

8. The battery pack of claim 7, wherein a plurality of insulating protective covers at the same end of the case in the second direction are integrally formed.

9. The battery pack of claim 1, wherein the length of the pole string is greater than 400mm; the electrode core groups comprise first electrode leading-out parts and second electrode leading-out parts which are used for leading out current, the first electrode leading-out parts and the second electrode leading-out parts are distributed on two opposite sides of the electrode core groups along a second direction, and the first electrode leading-out parts of one electrode core group in two adjacent electrode core groups are electrically connected with the second electrode leading-out parts of the other electrode core group.

10. The battery pack according to claim 9, wherein a plurality of the pole core strings are provided in the accommodation chamber, the plurality of pole core strings are sequentially arranged and electrically connected in a thickness direction of a pole core group, the thickness direction of the pole core group is parallel to a third direction, the second direction is a length direction of the case, and the third direction is a width direction of the case; or, the second direction is the width direction of the box body, and the third direction is the length direction of the box body.

11. The battery pack of claim 10, wherein a plurality of said strings of poles within the same said containment cavity are connected in series;

the first electrode lead-out part of the first electrode core group of one of the two adjacent electrode core strings is positioned at the same side with the second electrode lead-out part of the first electrode core group of the other electrode core string, or, the second electrode lead-out part of the last pole core group of one pole core string of the two adjacent pole core strings is positioned on the same side as the first electrode lead-out part of the last pole core group of the other pole core string.

12. The battery pack of claim 11, wherein a plurality of pole pieces within the same receiving cavity are connected in series-parallel;

a first pole core group of one pole core string of the two adjacent pole core strings is electrically connected with a first pole core group of the other pole core string, and a last pole core group of the one pole core string of the two adjacent pole core strings is electrically connected with a last pole core group of the other pole core string;

The first electrode leading-out part of the first electrode core group of one electrode core string of the two adjacent electrode core strings is positioned at the same side with the first electrode leading-out part of the first electrode core group of the other electrode core string, and the second electrode leading-out part of the last electrode core group of the one electrode core string of the two adjacent electrode core strings is positioned at the same side with the second electrode leading-out part of the last electrode core group of the other electrode core string.

13. The battery pack of claim 12, wherein the strings of pole pieces in adjacent two of the receiving chambers are connected in series;

the first electrode lead-out part of one of the electrode lead-out parts of the adjacent two containing cavities is positioned on the same side, or the last electrode lead-out part of the one of the electrode lead-out parts of the adjacent two containing cavities is positioned on the same side as the last electrode lead-out part of the one of the electrode lead-out parts of the adjacent two containing cavities.

14. The battery pack of claim 13, wherein the pole pieces in adjacent two of the receiving chambers are connected in series-parallel;

a first pole core group of one pole core string in one of the two adjacent accommodating cavities is electrically connected with a first pole core group of one pole core string in the other accommodating cavity, and a last pole core group of one pole core string in one of the two adjacent accommodating cavities is electrically connected with a last pole core group of one pole core string in the other accommodating cavity;

the first electrode leading-out part of the first electrode core group of one of the electrode core strings in one of the two adjacent accommodating cavities is positioned on the same side as the first electrode leading-out part of the first electrode core group of one of the electrode core strings in the other accommodating cavity, and the second electrode leading-out part of the last electrode core group of one of the electrode core strings in one of the two adjacent accommodating cavities is positioned on the same side as the second electrode leading-out part of the last electrode core group of one of the electrode core strings in the other accommodating cavity.

15. The battery pack of claim 14, wherein a pole string is disposed within the receiving cavity; the pole core strings in the two adjacent accommodating cavities are connected in series or in parallel;

When the pole core strings in the adjacent two accommodating cavities are connected in series, the first pole core group of the pole core string in one of the adjacent two accommodating cavities is electrically connected with the first pole core group of the pole core string in the other accommodating cavity, or the last pole core group of the pole core string in one of the adjacent two accommodating cavities is electrically connected with the last pole core group of the pole core string in the other accommodating cavity;

when the pole core groups in the adjacent two accommodating cavities are connected in parallel, the first pole core group of the pole core string in one of the adjacent two accommodating cavities is electrically connected with the first pole core group of the pole core string in the other accommodating cavity, and the last pole core group of the pole core string in the one of the adjacent two accommodating cavities is electrically connected with the last pole core group of the pole core string in the other accommodating cavity.

16. The battery pack of claim 1, wherein the plurality of pole core groups comprising a pole core string are encapsulated in an encapsulation film; the electrode core group comprises an electrode core group main body, a first electrode lead-out part and a second electrode lead-out part, wherein the first electrode lead-out part and the second electrode lead-out part are used for leading out current, and the joint of the first electrode lead-out part of one electrode core group and the second electrode lead-out part of the other electrode core group in the two electrode core groups which are connected in series is positioned in the packaging film; and a packaging part is formed at the relative position of the packaging film and the first electrode leading-out part and/or the second electrode leading-out part so as to isolate adjacent two-pole core group bodies.

17. The battery pack of claim 1, wherein each of the pole pieces is individually encapsulated in an encapsulation film to form pole piece assemblies, the pole piece assemblies being connected in series.

18. The battery pack of claim 1, wherein the air pressure within the receiving chamber is lower than the air pressure outside the case.

19. The battery pack of claim 18, wherein the housing is provided with glue injection holes, and each of the receiving cavities is in corresponding communication with at least one of the glue injection holes.

20. The battery pack of claim 19, wherein adjacent two pole core groups constituting a pole core string are electrically connected by a second conductive member, and the glue injection hole is provided corresponding to the second conductive member.

21. The battery pack of claim 20, wherein a second explosion-proof valve is provided on the case, the second explosion-proof valve sealing the glue injection hole.

22. The battery pack of claim 21, wherein the second explosion proof valve has a weakened area; the second explosion-proof valve comprises a cover body and a protruding portion, wherein the cover body is in sealing connection with the box body, the protruding portion is arranged on the cover body, the protruding portion protrudes towards one side, deviating from the pole core group, of the protruding portion, and the weak area is formed in the peripheral wall of the protruding portion.

23. The battery pack of claim 1, further comprising a plurality of liquid cooling members disposed on the bottom plates of the plurality of sub-tanks, the plurality of liquid cooling members being integrally formed.

24. The battery pack of claim 1, wherein the case further comprises first and second side rails disposed on opposite sides of the case body in a third direction;

a plurality of structural beams are arranged in each sub-box body, the structural beams are distributed at intervals along a third direction, the length of each structural beam extends along a second direction, and each structural beam is connected with the top plate and the bottom plate; at least one of the top plate and the bottom plate is integrally formed with the structural beam;

the second direction is the length direction of the box body, and the third direction is the width direction of the box body; or, the second direction is the width direction of the box body, and the third direction is the length direction of the box body.

25. An electric vehicle comprising a vehicle body and the battery pack according to any one of claims 1 to 24, the battery pack being fixed to the vehicle body by the mounting portion.