CN112331989B

CN112331989B - Battery module, battery pack, vehicle and assembly method of battery module

Info

Publication number: CN112331989B
Application number: CN201910886971.3A
Authority: CN
Inventors: 王旭光; 侯羽佳; 姚己华
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2019-09-19
Filing date: 2019-09-19
Publication date: 2021-12-21
Anticipated expiration: 2039-09-19
Also published as: CN112331989A

Abstract

The application relates to a battery module, a battery pack, a vehicle and an assembly method of the battery module, wherein the battery module comprises: a battery cell arrangement structure including a plurality of battery cells arranged in a length direction of the battery module; end plates located at both ends of the battery cell arrangement structure in a length direction; the cover plate comprises a first cover plate and a second cover plate, and the first cover plate and the second cover plate are positioned at two ends of the battery unit arrangement structure along the height direction; the end plate is connected with the first cover plate in a clamping mode, and the end plate is connected with the second cover plate in a clamping mode. In this application, this end plate is connected with the equal joint of first apron and second apron, does not adopt welded mode to be connected between end plate and the apron promptly to can avoid battery module to reduce gradually with the welding reliability of apron in the use end plate, the connected mode of end plate and two apron joints promptly can improve the reliability of being connected between end plate and the apron, thereby improves battery module's life.

Description

Battery module, battery pack, vehicle and assembly method of battery module

Technical Field

The application relates to the technical field of energy storage devices, in particular to a battery module, a battery pack, a vehicle and an assembly method of the battery module.

Background

The battery module comprises a battery unit and a frame structure, wherein the battery unit is positioned in an inner cavity of the frame structure, and the frame structure comprises an end plate and a cover plate which are connected with each other and enclose the inner cavity. Under the normal condition, the end plate is connected with the apron and is adopted modes such as welding to be connected, however, in the battery module use, the welded connection reliability between end plate and the apron reduces gradually, leads to battery module life to reduce.

Disclosure of Invention

The application provides a battery module, a battery pack, a vehicle and an assembly method of the battery module, which can improve the connection reliability between an end plate and a cover plate and prolong the service life.

A first aspect of an embodiment of the present application provides a battery module, the battery module includes:

a battery cell arrangement structure including a plurality of battery cells arranged in a length direction of the battery module;

end plates located at both ends of the battery cell arrangement structure in a length direction;

the cover plate comprises a first cover plate and a second cover plate, and the first cover plate and the second cover plate are positioned at two ends of the battery unit arrangement structure along the height direction;

the end plate is connected with the first cover plate in a clamping mode, and the end plate is connected with the second cover plate in a clamping mode.

In one possible design, the battery module includes two or more of the battery cell arrangement structures, and the battery cell arrangement structures are stacked in a height direction;

the battery unit includes a positive electrode terminal and a negative electrode terminal, and the positive electrode terminal and the negative electrode terminal face in a width direction of the battery module.

In one possible design, the first cover plate and the second cover plate each include a first body plate and a hook, the first body plate being connected with the hook;

the end plate is provided with a concave part, and the clamping hook is clamped in the concave part.

In one possible design, the recessed portion is provided on the outer end face of the end plate away from the battery cell and recessed in a direction closer to the battery cell;

the clamping hook comprises a clamping section and an extension section, and two ends of the extension section are respectively connected with the clamping section and the first body plate;

the extension section extends along the height direction, the clamping section extends along the length direction and extends along the inner side close to the battery unit, and at least part of the clamping section is located in the concave part.

In one possible design, the recess includes a first recess and a second recess, the first recess and the second recess being arranged in a height direction of the battery module;

the first depressed part is connected with the first cover plate through the clamping hook in a clamped mode, and the second depressed part is connected with the second cover plate through the clamping hook in a clamped mode.

In one possible design, the battery module further includes a connection member that connects the first cover plate and the second cover plate in a height direction of the battery module.

In one possible design, the connection member includes a second body plate and two protrusions, which are connected to both ends of the second body plate, respectively, in a height direction of the battery module;

the first cover plate and the second cover plate are both provided with mounting grooves, and at least parts of the two bulges are respectively positioned in the mounting grooves of the first cover plate and the mounting grooves of the second cover plate;

the mounting groove comprises a bottom wall, and the protrusion is abutted to the bottom wall.

In one possible design, the bottom wall is provided with a first opening, the second body plate passing through the first openings of both the mounting slots;

along the length direction, the second body plate is positioned in a first preset gap between two adjacent battery cells.

In one possible design, the mounting groove includes an outer side wall away from the battery cell in a width direction of the battery module, the outer side wall being provided with a second opening.

In one possible design, a first extension plate is connected to each of the first cover plate and the second cover plate, extends in the height direction of the battery module, and extends in a direction close to the battery unit;

the first cover plate and the second cover plate are both connected with a second extension plate, and the second extension plate extends along the height direction of the battery module and extends along the direction close to the battery unit;

the first extending plate and the second extending plate are provided with a second preset gap along the length direction of the battery module, the second body plate is located in the second preset gap, and the second body plate is abutted to the first extending plate and the second extending plate;

the first preset gap is communicated with the second preset gap.

A second aspect of the embodiments of the present application provides a battery pack, including:

a case having a cavity;

the battery module is the battery module;

wherein, the battery module is located the cavity.

A third aspect of embodiments of the present application provides a vehicle, including:

a vehicle body;

the driving system comprises a battery pack and is used for driving the vehicle body to move;

wherein, the battery package is the above-mentioned battery package.

A fourth aspect of the embodiments of the present application provides a method for assembling a battery module, where the battery module includes a battery cell arrangement structure, an end plate, and a cover plate; the end plates are positioned at two ends of the battery unit arrangement structure along the length direction, and the cover plates are positioned at two ends of the battery unit arrangement structure along the height direction; one of the cover plate and the end plate is provided with a concave part, and the other one is provided with a clamping hook; the assembling method comprises the following steps:

applying a pre-tightening force to the end plates and the battery cell arrangement structure along the length direction;

aligning the corresponding hooks with the recesses;

and releasing the pretightening force to enable the clamping hook to be clamped with the concave part.

In one possible design, the cover plate comprises a first cover plate and a second cover plate which are arranged along the height direction, and the first cover plate and the second cover plate are both provided with mounting grooves; the battery module further includes a connection member including a second body plate and two protrusions;

the assembly method further comprises:

applying pretightening force to the first cover plate, the second cover plate and the battery unit arrangement structure along the height direction of the battery module;

aligning the protrusions of the connection member with the mounting grooves of the first and second cover plates, respectively, and placing the second body plate between adjacent battery cells;

releasing the pretightening force so that at least part of the protrusion is positioned in the corresponding mounting groove, and the protrusion is abutted against the bottom wall of the corresponding mounting groove so as to connect the first cover plate and the second cover plate in the height direction through the connecting part. In this application, this end plate is connected with the equal joint of first apron and second apron, does not adopt welded mode to be connected between end plate and the apron promptly to can avoid battery module to reduce gradually with the welding reliability of apron in the use end plate, the connected mode of end plate and two apron joints promptly can improve the reliability of being connected between end plate and the apron, thereby improves battery module's life.

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 application.

Drawings

Fig. 1 is an exploded view of a battery module provided herein in one embodiment;

FIG. 2 is an enlarged view of a portion I of FIG. 1;

FIG. 3 is a side view of FIG. 1;

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

FIG. 5 is a sectional view taken along line A-A of FIG. 3;

FIG. 6 is an enlarged view of a portion III of FIG. 5;

FIG. 7 is an enlarged view of a portion IV of FIG. 5;

FIG. 8 is a schematic view of the structure of FIG. 1 with the harness isolation panel and side panel removed;

FIG. 9 is an enlarged view of a portion V of FIG. 8;

FIG. 10 is a schematic view of the connecting member of FIG. 8 with the connecting member removed;

FIG. 11 is a schematic structural view of the end plate of FIG. 10;

FIG. 12 is a schematic view of the cover plate of FIG. 10;

FIG. 13 is an enlarged view of a portion VI of FIG. 12;

FIG. 14 is an enlarged fragmentary view of portion VII of FIG. 12;

fig. 15 is a schematic view of the structure of the connection member of fig. 8.

Reference numerals:

a-a battery module;

1-an end plate;

11-a recess;

111-a first recess;

112-a second recess;

12-a first notch portion;

13-a second notch portion;

14-an outer end face;

2-cover plate;

21-a first cover plate;

22-a second cover plate;

23-hook;

231-an extension section;

232-clamping section;

24-a first body plate;

241-a first reinforcing rib;

242-a second reinforcing bead;

243-a third reinforcing rib;

25-a reinforcing plate;

26-mounting grooves;

261-an outer side wall;

261 a-a second opening;

262-a bottom wall;

262 a-a first opening;

27-a first extension plate;

28-a second extension panel;

3-a connecting member;

31-a second body plate;

32-protrusions;

4-cell arrangement structure;

41-battery cell;

411-top cover plate;

412-positive electrode terminal;

413-negative electrode terminal;

5-a wiring harness isolation plate;

6-side plate;

7-a buffer pad;

t-a first preset gap;

m-a second predetermined gap.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Detailed Description

For better understanding of the technical solutions of the present application, the following detailed descriptions of the embodiments of the present application are provided with reference to the accompanying drawings.

It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be noted that the terms "upper", "lower", "left", "right", and the like used in the embodiments of the present application are described in terms of the angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In addition, in this context, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on "or" under "the other element or be indirectly on" or "under" the other element via an intermediate element.

The embodiment of the application provides a vehicle, battery package and battery module A, wherein, the vehicle includes automobile body and actuating system, and this actuating system is used for driving the automobile body and goes along the road, and this actuating system includes the battery package at least, and this vehicle specifically can be electric automobile, hybrid vehicle, electric bicycle, electric motorcycle car etc..

The battery pack comprises a box body and a battery module A arranged in the box body, wherein the box body can be made of aluminum, aluminum alloy or other metal materials, and an accommodating cavity is formed in the box body. In one possible design, the box body is a box body structure with an open top, and comprises an upper box cover, the size of the upper box cover is equivalent to that of an opening at the top of the box body, and the upper box cover can be fixed to the opening through fixing pieces such as bolts, so that an accommodating cavity is formed. Meanwhile, in order to improve the sealing performance of the box body, a sealing element can be arranged between the upper box cover and the box body.

The battery module A can be set up side by side along the length direction X of battery package in the holding intracavity of box, and battery module A also can set up side by side along the width direction Y of battery package in the box, and each battery module A can be fixed with the box.

As shown in fig. 1, the battery module a includes a plurality of battery cells 41 and a frame structure, wherein the plurality of battery cells 41 are arranged along a length direction X of the battery module a to form a battery cell arrangement structure 4, and the battery module a may include one or more battery cell arrangement structures 4; the frame structure comprises end plates 1, a cover plate 2 and side plates 6, wherein the end plates 1 are positioned at two ends of the battery unit arrangement structure 4 along the length direction X; the cover plate 2 includes a first cover plate 21 and a second cover plate 22, the first cover plate 21 and the second cover plate 22 are located at two ends of the battery unit arrangement structure 4 along the height direction Z of the battery module a, the side plates 6 are located at two ends of the battery unit arrangement structure 4 along the width direction a of the battery module a, and the end plates 1, the side plates 6 and the cover plates 2 are connected, so that a frame structure of the battery module a is formed, and an inner cavity for accommodating the battery unit arrangement structure 4 is enclosed.

Wherein, in this application, this end plate 1 is connected with first apron 21 and the equal joint of second apron 22, does not adopt welded mode to be connected between end plate 1 and the apron 2 promptly to can avoid battery module A to reduce gradually with the welding reliability of apron in the use end plate, the connected mode of end plate 1 and two apron 21 joints promptly can improve the connected reliability between end plate 1 and the apron 2, thereby improves battery module's life.

Meanwhile, as shown in fig. 1, the battery module a further includes a harness isolation plate 5, the harness isolation plate 5 being located near one end of the electrode terminals of the battery cells 41, the harness isolation plate 5 serving to prevent the battery cells 41 from being short-circuited with other components.

Specifically, as shown in fig. 13, the first cover plate 21 and the second cover plate 22 each include a first body plate 24 and a hook 23, and the first body plate 24 and the hook 23 are fixedly connected or integrally formed; accordingly, as shown in fig. 11, the end plate 1 is provided with a recess 11, and the hook 23 is fastened to the recess 11. In this embodiment, the end plate 1 has a large thickness, and the provision of the recessed portion 11 has little influence on the strength thereof.

As shown in fig. 12 and 13, the first body plate 24 further includes a first rib 241, a second rib 242, and a third rib 243, wherein the first rib 241 and the second rib 242 are perpendicular to each other, that is, the first rib 241 extends along the length direction X, the second rib 242 extends along the height direction Z, the third rib 243 is disposed at two ends of the first reinforcing plate 24 along the length direction X, and the hook 23 is connected to the third rib 243, so as to improve the strength of the hook 23 and the reliability of the hook 23 being engaged with the recess 11 of the end plate 1.

In a possible design, as shown in fig. 1, the battery module a further includes a buffer pad 7, the buffer pad 7 is made of an elastic material, the buffer pad 7 is located between adjacent battery cells 41 along the length direction X, when both ends of the first cover plate 21 and the second cover plate 22 along the length direction X are clamped with the cover plate 1, a pressing force can be applied to the buffer pad 7, and when the pressing force disappears, the buffer pad 7 can rebound, so that the impact load between the connected battery cells 41 can be buffered by the buffer pad 7.

As shown in fig. 6 and 11, this recessed portion 11 is provided on the outer end face 14 of the end plate 1 away from the battery cell 41, and is recessed in a direction closer to the battery cell 41; accordingly, as shown in fig. 6 and 13, the hook 23 includes a clamping section 232 and an extending section 231, two ends of the extending section 231 are respectively connected to the clamping section 232 and the first body plate 24, the extending section 231 extends along the height direction Z, the clamping section 232 extends along the length direction X and extends along the inner side close to the battery unit 41, and at least a portion of the clamping section 232 is located in the recess 11.

In this embodiment, by providing the extension 231 extending along the height direction Z, the hook 23 can extend downward from the top of the end plate 1 and extend to the outer side of the end plate 1 along the length direction X, that is, the hook 23 is engaged with the recess 11 at the outer side of the end plate 1, and the engaging structure does not need to occupy the space inside the battery module a.

The depressed part 11 is of a groove-shaped structure, that is, the depressed part 11 does not penetrate through the end plate 1, so that the situation that the sealing performance of the inner cavity of the battery module a is reduced due to the opening of the end plate is avoided, and when the battery unit 41 expands outwards, the groove-shaped depressed part 11 can also avoid a short circuit caused by the contact of the clamping section 232 and the battery unit 41; meanwhile, when the recessed portion 11 is formed in a groove-like structure, the strength of the end plate 1 can be prevented from being too low. In addition, as shown in fig. 6, when the recessed portion 11 is engaged with the latching section 232, a gap is formed between the latching section 232 and the bottom wall of the recessed portion 11, so as to reduce the impact load between the hook 23 and the end plate 1.

In one possible design, as shown in fig. 10, the recessed portion 11 includes a first recessed portion 111 and a second recessed portion 112, and the first recessed portion 111 and the second recessed portion 112 are arranged along a height direction Z of the battery module a, and at the same time, along a width direction Y of the battery module, the end plate 1 is provided with a plurality of first recessed portions 111 and a plurality of second recessed portions 112, and accordingly, along the width direction Y, the first cover plate 21 is provided with a plurality of hooks 23, the second cover plate 22 is provided with a plurality of hooks, and further, along the length direction X, both ends of the end plate 1 are provided with the first recessed portions 111 and the second recessed portions 112, both ends of the first cover plate 21 and the second cover plate 22 are provided with hooks, and the first recessed portion 111 is engaged with the hook 23 of the first cover plate 21, and the second recessed portion 112 is engaged with the hook 23 of the second cover plate 22.

In this embodiment, the plurality of recesses 11 and the plurality of hooks 23 are engaged with each other, so that the end plate 1 and the two cover plates 2 can be engaged with each other, and the connection reliability between the two cover plates can be improved.

Specifically, as shown in fig. 11, the end plate 1 is provided with a first notch portion 12 and a second notch portion 13, the first notch portion 12 and the second notch portion 13 are provided to face each other in the height direction Z, the first recess portion 111 is provided on a side wall of the first notch portion 12, and the second recess portion 112 is provided on a side wall of the second notch portion 13. In this embodiment, the thickness (dimension in the longitudinal direction X) of the end plate 1 at the position of the notch portion is small, and the dimension of the extension 232 can be reduced, so that the weight of the battery module a can be reduced, and the energy density can be improved.

In this application, along length direction X, this first apron 21's both ends and two end plate 1 joint, simultaneously, the both ends and the 1 joint of two end plate of second apron 22, behind the joint, two end plate 1 and two apron 2 restrict each battery unit 41 along length direction X motion, however, when battery module A is great along length direction X's size, apron 2 only when length direction X's both ends are connected with end plate 1, the risk of following the perk of direction of height Z exists in apron 2's middle part.

In order to solve the technical problem, as shown in fig. 1, the battery module a further includes a connection member 3, and the connection member 3 connects the first cover plate 21 and the second cover plate 22 in the height direction Z of the battery module a. Meanwhile, the battery module a may include one connection member or a plurality of connection members 3 disposed at intervals in the length direction X according to the size of the battery module a in the length direction X, thereby preventing the cover plate 2 from being tilted.

Specifically, in the embodiment shown in fig. 1, the battery module a includes two or more cell arrangement structures 4, in each cell arrangement structure 4, a plurality of battery cells 41 are arranged in the length direction X, and each cell arrangement structure 4 is stacked in the height direction Z.

It should be noted that the "longitudinal direction" herein refers to the same direction as the arrangement direction of the battery cells 41 in the battery cell arrangement structure 4, and the direction indicated by the longitudinal direction changes when the arrangement direction of the battery cells 41 changes, for example, as shown in fig. 1, when the respective battery cells 41 are arranged in the Y direction, the longitudinal direction refers to the Y direction in fig. 1. Therefore, the terms "longitudinal" and the like should not be construed as absolutely limiting the scope of the present application.

The battery unit 41 includes a casing, one or more electrode assemblies located inside the casing, and a top cover plate 411 covering an opening of the casing, where the electrode unit includes a negative electrode plate, a positive electrode plate, and an isolation film located between the adjacent negative electrode plate and the positive electrode plate for separating the negative electrode plate and the positive electrode plate. The battery cell 41 further includes a positive electrode terminal 412 and a negative electrode terminal 413, the positive electrode terminal 412 being connected to a positive tab extending from the electrode assembly, and the negative electrode terminal 413 being connected to a negative tab extending from the electrode assembly. In the present embodiment, the positive electrode terminal 412 and the negative electrode terminal 413 face the width direction Y of the battery module a.

In one possible design, the negative electrode sheet, the separator and the positive electrode sheet are sequentially stacked and wound to form an electrode unit of the electrode assembly, that is, the electrode unit is in a wound structure. Meanwhile, the electrode unit is provided with a gap after being formed, and electrolyte can enter the electrode unit through the gap to soak the negative pole piece and the positive pole piece.

In the above two embodiments, the electrode assembly expands in the thickness direction of the pole piece during charging and discharging, specifically, in the embodiment shown in fig. 1, the expansion force of the electrode assembly in the height direction Z is the largest, that is, the deformation tendency of the electrode assembly in the height direction Z is the largest under the expansion force, and the expansion force of each battery cell 41 acting on the cover plate 2 in the height direction Z is the largest, so that the risk of the two cover plates 2 tilting in the height direction Z is higher. When this battery module A sets up adapting unit 3 and connects two apron 2 along direction of height Z, can reduce the risk of apron 2 perk under the effect of expansive force, improve battery module A's life.

Meanwhile, in order to further improve the connection reliability between the two cover plates 2, the two ends of the battery module a in the width direction Y are provided with the connecting parts 3, and the two ends in the width direction a are provided with one or more connecting parts 3, the connecting parts 3 are arranged at intervals in the length direction X, therefore, in the length direction X, under the effect of the expansion force of the battery unit 41, the two cover plates 2 have higher connection reliability at each position of the battery module a, and therefore the battery module a has longer service life.

Specifically, as shown in fig. 15, the connecting member 3 includes a second body plate 31 and two protrusions 32, the two protrusions 32 being connected to both ends of the second body plate 31, respectively, in the height direction Z of the battery module a; accordingly, as shown in fig. 2 and 14, the first cover plate 21 and the second cover plate 22 are each provided with a mounting groove 26, as shown in fig. 7, at least a portion of the two protrusions 32 are respectively located in the mounting groove 26 of the first cover plate 21 and the mounting groove 26 of the second cover plate 22, and the mounting groove 26 includes a bottom wall 262, the bottom wall 262 is perpendicular to the width direction Y of the battery module a, and the protrusions 32 abut against the bottom wall 262 when located in the mounting groove 26.

In this embodiment, at least a part of the two protrusions 32 of the connecting member 3 is located in the mounting grooves 26 of the two cover plates 2, respectively, and the two protrusions 32 are abutted against the bottom walls 262 of the two mounting grooves 26, respectively, so that the connecting member 3 connects the two cover plates 2 in the height direction Z.

As shown in fig. 7, the protrusion 32 is adapted to the mounting groove 26, that is, when the connecting component 3 is connected to the cover plate 2, the protrusion 32 is entirely located in the mounting groove 26, and the bottom wall of the protrusion 32 abuts against the bottom wall 262 of the mounting groove 26, and the top wall of the protrusion 32 is flush with the outer wall of the cover plate 2.

More specifically, as shown in fig. 12, the first cover plate 21 and the second cover plate 22 each have a reinforcing plate 25, and the reinforcing plate 25 protrudes outward in the width direction Y with respect to the first body plate 24, so as to increase the thickness of the first cover plate 21 and the second cover plate 22 at that position, and the mounting groove 26 is provided at the reinforcing plate 25, so that the first cover plate 21 and the second cover plate 22 have high strength even after the mounting groove 26 is provided, and the connection reliability of the connection member 3 with the first cover plate 21 and the second cover plate 22 is improved.

In a specific embodiment, as shown in fig. 2 and 9, the bottom wall 262 is provided with a first opening 262a, and the second body plate 31 passes through the first openings 262a of the two mounting grooves 26, and the second body plate 31 is located in the first preset gap t between the adjacent two battery cells 41 in the length direction X.

In this embodiment, the first opening 262a is provided to allow the second body plate 31 of the connecting member 3 to pass through the first opening 262a, and to allow the second body plate 31 to be positioned inside the battery module a without protruding from the battery module a, thereby reducing the space occupied by the battery module a.

Specifically, as shown in fig. 2, the mounting groove 26 includes an outer sidewall 261 away from the battery cells 41 in the width direction Y of the battery module a, the outer sidewall 261 is provided with a second opening 261a, the second opening 261a communicates with the first opening 262a, and the first body plate 31 of the coupling part 3 protrudes into the predetermined gap t between the adjacent battery cells 41 through the second opening 261a when mounted. In this embodiment, the second opening 261a is provided, so that the connecting member 3 can be easily connected to the first cover 21 and the second cover 22.

Further, as shown in fig. 14, a first extension plate 27 is connected to each of the first cover plate 21 and the second cover plate 22, the first extension plate 27 extends in the height direction Z of the battery module a and extends in a direction close to the battery cell 41, and a second extension plate 28 is connected to each of the first cover plate 21 and the second cover plate 22, and the second extension plate 28 extends in the height direction Z of the battery module a and extends in a direction close to the battery cell 41. Specifically, as shown in fig. 7, the first extending plate 27 and the second extending plate 28 are respectively aligned with the side wall of the first opening 262a, i.e. they respectively extend from the side wall of the first opening 262a toward the battery unit 41, i.e. the first extending plate 27 and the second extending plate 28 are arranged along the length direction X of the battery module a, and there is a second preset gap m therebetween along the length direction X, the second preset gap m is communicated with the first preset gap t, and m is less than or equal to t in the second preset gap m and the first preset gap t.

In this embodiment, the first extension plate 27 and the second extension plate 28 are disposed on the two cover plates 2, so that the second body plate 31 of the connecting member 3 is located in the second predetermined gap m, and the second body plate 31 abuts against both the first extension plate 27 and the second extension plate 28, which can increase the connecting area between the second body plate 31 and the first cover plate 21 and the second cover plate 22 (the increased connecting area is the abutting area between the second body plate 31 and the first extension plate 27 and the second extension plate 28), thereby improving the connecting reliability between the connecting member 3 and the first cover plate 21 and the second cover plate 22.

Of course, the contact area between the first extension plate 27 and the connection member 3 is increased and the connection reliability is increased as the dimension of the first extension plate 27 and the second extension plate 28 in the height direction Z is increased, but when the dimension of the first extension plate 27 and the second extension plate 28 in the height direction Z is excessively increased, the weight of the battery module a is increased and the energy density is decreased. Therefore, in actual working conditions, the size of the two extension plates can be reasonably set by comprehensively considering the factors of the connection reliability and the energy density.

In addition, an assembly method of a battery module a is further provided in the embodiments of the present application, as shown in fig. 1, the battery module a specifically includes a battery cell arrangement structure 4, an end plate 1 and a cover plate 2, where the battery cell arrangement structure 4 includes a plurality of battery cells 41 stacked along a length direction X, the end plate 1 is located at two ends of the battery cell arrangement structure 4 along the length direction X, and the cover plate 2 is located at two ends of the battery cell arrangement structure 4 along a height direction Z. Meanwhile, one of the cover plate 2 and the end plate 1 is provided with the recess 11, and the other is provided with the hook 23, that is, when the end plate 1 and the cover plate 2 of the above embodiments are clamped, the positions of the recess 11 and the hook 23 are not limited, that is, the recess 11 is not necessarily provided on the end plate 1, and the hook 23 is not necessarily provided on the cover plate 2. Based on this, the method for assembling the battery module a includes the steps of:

s1: pretension is applied to the end plate 1 and the battery cell arrangement structure 4 along the length direction X.

Specifically, when the battery module a includes the buffer pads 7, the buffer pads 7 are first placed between the adjacent battery cells 41 to form the battery cell arrangement structure 4, the battery cell arrangement structure 4 is stacked in a preset direction (length direction X) as needed, and the two end plates 1 are respectively placed at the two ends of the battery cell arrangement structure 41 in the length direction X; and applying pretightening force along the length direction X through the tool so that the cushion pad 7 is compressed.

S2: aligning the corresponding hook 23 with the recess 11;

s3: the pre-tightening force is released, so that the hook 23 is clamped with the concave part 11.

In this embodiment, after the hook 23 is aligned with the recessed portion 11 and releases the pre-tightening force, under the effect of the resilience of the cushion pad 7 and the battery unit 41, the two end plates 1 respectively move in the direction away from the battery unit 41, so as to realize the engagement between the hook 23 and the recessed portion 11, and limit the displacement of the end plate 1 and the cover plate 2 in the length direction X, the width direction Y and the height direction Z by the engagement structure. In one possible design, the first cover plate 21 and the second cover plate 22 are each provided with a mounting groove 26, the battery module a further includes a coupling member 3, the coupling member 3 includes a second body plate 31 and two protrusions 32, and the two protrusions 32 are coupled to both ends of the second body plate 31. Based on this, the above assembling method further includes:

s4: a pretension force is applied to the first cover plate 21, the second cover plate 22 and the battery cell arrangement structure 4 in the height direction Z of the battery module a.

Specifically, in this embodiment, a pre-tightening force is applied by the tool in the height direction Z, so that the battery cell 41 is compressed, and the size of the battery cell arrangement structure 4 in the height direction Z is reduced.

S5: the protrusions 32 of the connection member 3 are aligned with the mounting grooves 26 of the first and

second cover plates

21 and 22, respectively, and the second body plate 31 is placed between the adjacent battery cells 41.

In this step, the connecting member 3 is loaded in the width direction Y, and specifically, the second body plate 31 is inserted between the adjacent battery cells 41 through the second opening 261a such that the two protrusions 32 are aligned with the mounting grooves 26 of the first cover plate 21 and the mounting grooves 26 of the second cover plate 22, respectively.

S6: the preload is released so that at least a part of the protrusion 32 is located in the corresponding mounting groove 26, and the protrusion 32 abuts against the bottom wall 262 of the corresponding mounting groove 26, so as to connect the first cover plate 21 and the second cover plate 22 in the height direction Z by the connection member 3.

In this step, after the pretightening force along the height direction Z is released, the battery unit 41 is rebounded, and the two protrusions 32 of the connection component 3 along the height direction Z are respectively located in the mounting grooves 26 of the first cover plate 21 and the second cover plate 22, so that the first cover plate 21 and the second cover plate 22 are limited along the length direction X, the width direction Y and the height direction Z by the connection component 3.

It should be noted that, the above steps S1, S2 and S3 are not necessarily located before S4, S5 and S6, and S4, S5 and S6 may also be located before S1, S2 and S3, that is, when the battery module a is assembled, the first cover plate 21 and the second cover plate 22 are first connected in the height direction Z by the connecting member 3, so as to complete the position limitation of the two cover plates 2 and the battery cell arrangement structure 4 in the height direction Z, and then the end plate 1 is clamped with the cover plate 2 by the hooks 23 and the recesses 11, so as to connect the end plate 1 with the cover plate 2 in the length direction X, the width direction Y and the height direction Z, and to realize the position limitation of the battery cell arrangement structure 4 in the length direction X, the width direction Y and the height direction Z by the end plate 1 and the cover plate 2.

However, when S1, S2, and S3 are located before S4, S5, and S6, positioning of the two cover plates 2 can be achieved by snapping the end plate 1 to the cover plates 2, thereby reducing difficulty in connecting the two cover plates 2 of the member 3.

To sum up, in this application, through being connected two apron 2 and end plate 1 joint, the reduction of welded connection reliability when can avoiding the two welding guarantees battery module A's life, and simultaneously, this adapting unit 3 can also be followed direction of height Z and connected first apron 21 and second apron 22 to prevent first apron 21 and the perk of second apron 22, so that further improve battery module A's life. In addition, when the expansion force of the battery cell 41 in the height direction Z is the largest, the first cover plate 21 and the second cover plate 22 are connected by the connection member 3, so that they still have high connection reliability under the expansion force.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery module characterized in that the battery module (A) comprises:

a battery cell arrangement structure (4) including a plurality of battery cells (41) arranged in a longitudinal direction (X) of the battery module (A);

end plates (1) located at both ends of the battery cell arrangement structure (4) in a length direction (X);

a cover plate (2) including a first cover plate (21) and a second cover plate (22), the first cover plate (21) and the second cover plate (22) being located at both ends of the battery cell arrangement structure (4) in a height direction (Z);

the end plate (1) is connected with the first cover plate (21) in a clamping mode, and the end plate (1) is connected with the second cover plate (22) in a clamping mode;

the battery module (A) further comprises a connecting part (3), and the connecting part (3) is connected with the first cover plate (21) and the second cover plate (22) along the height direction (Z) of the battery module (A).

2. The battery module according to claim 1, wherein the battery module (a) includes two or more of the battery cell arrangement structures (4), and the battery cell arrangement structures (4) are stacked in a height direction (Z);

the battery unit (41) includes a positive electrode terminal (412) and a negative electrode terminal (413), and the positive electrode terminal (412) and the negative electrode terminal (413) face in a width direction (Y) of the battery module (A).

3. The battery module according to claim 1, wherein the first cover plate (21) and the second cover plate (22) each include a first body plate (24) and a hook (23), the first body plate (24) being connected with the hook (23);

the end plate (1) is provided with a concave part (11), and the clamping hook (23) is clamped in the concave part (11).

4. The battery module according to claim 3, wherein the recessed portion (11) is provided at an outer end face (14) of the end plate (1) remote from the battery cell (41) and recessed in a direction approaching the battery cell (41);

the clamping hook (23) comprises a clamping section (232) and an extension section (231), and two ends of the extension section (231) are respectively connected with the clamping section (232) and the first body plate (24);

the extension section (231) extends along the height direction (Z), the clamping section (232) extends along the length direction (X) and extends along the inner side close to the battery unit (41), and at least part of the clamping section (232) is positioned in the concave part (11).

5. The battery module according to claim 3, wherein the recess (11) includes a first recess (111) and a second recess (112), the first recess (111) and the second recess (112) being arranged in a height direction (Z) of the battery module (A);

the first concave part (111) is connected with the first cover plate (21) through the clamping hook (23) in a clamped mode, and the second concave part (112) is connected with the second cover plate (22) through the clamping hook (23) in a clamped mode.

6. The battery module according to claim 1, wherein the connecting member (3) comprises a second body plate (31) and two protrusions (32), the two protrusions (32) being connected to both ends of the second body plate (31), respectively, in the height direction (Z) of the battery module (a);

the first cover plate (21) and the second cover plate (22) are both provided with mounting grooves (26), and at least parts of the two protrusions (32) are respectively positioned in the mounting grooves (26) of the first cover plate (21) and the mounting grooves (26) of the second cover plate (22);

the mounting groove (26) comprises a bottom wall (262), and the protrusion (32) is abutted to the bottom wall (262).

7. The battery module according to claim 6, wherein the bottom wall (262) is provided with first openings (262a), and the second body plate (31) passes through the first openings (262a) of the two mounting grooves (26);

the second body plate (31) is located in a first preset gap (t) between two adjacent battery cells (41) along the length direction (X).

8. The battery module according to claim 7, wherein the mounting groove (26) includes an outer side wall (261) away from the battery cell (41) in the width direction (Y) of the battery module (A), the outer side wall (261) being provided with a second opening (261 a).

9. The battery module according to claim 7, wherein a first extension plate (27) is attached to each of the first cover plate (21) and the second cover plate (22), the first extension plate (27) extending in a height direction (Z) of the battery module (A) and extending in a direction close to the battery cell (41);

a second extension plate (28) is connected to each of the first cover plate (21) and the second cover plate (22), and the second extension plate (28) extends in the height direction (Z) of the battery module (A) and extends in a direction close to the battery unit (41);

the first extension plate (27) and the second extension plate (28) have a second preset gap (m) along the length direction (X) of the battery module (A), the second body plate (31) is located at the second preset gap (m), and the second body plate (31) abuts against both the first extension plate (27) and the second extension plate (28);

the first preset gap (t) is communicated with the second preset gap (m).

10. A battery pack, comprising:

a case having a cavity;

a battery module (A) according to any one of claims 1 to 9;

wherein the battery module (A) is located in the cavity.

11. A vehicle, characterized in that the vehicle comprises:

a vehicle body;

wherein the battery pack is the battery pack according to claim 10.

12. An assembly method of a battery module (A), characterized in that the battery module (A) comprises a battery unit arrangement structure (4), an end plate (1) and a cover plate (2); the end plates (1) are positioned at two ends of the battery unit arrangement structure (4) along the length direction (X), and the cover plates (2) are positioned at two ends of the battery unit arrangement structure (4) along the height direction (Z); one of the cover plate (2) and the end plate (1) is provided with a concave part (11), and the other one is provided with a clamping hook (23); the cover plate (2) comprises a first cover plate (21) and a second cover plate (22) which are arranged along the height direction (Z), and the first cover plate (21) and the second cover plate (22) are both provided with mounting grooves (26); the battery module (A) further comprises a connecting member (3), the connecting member (3) comprising a second body plate (31) and two protrusions (32); the assembling method comprises the following steps:

applying a pre-tightening force to the end plate (1) and the cell arrangement structure (4) along a length direction (X);

aligning the corresponding catch (23) with the recess (11);

releasing the pretightening force to enable the clamping hook (23) to be clamped with the concave part (11);

applying a pre-tightening force to the first cover plate (21), the second cover plate (22) and the battery cell arrangement structure (4) along a height direction (Z) of the battery module (A);

aligning the protrusions (32) of the connection member (3) with the mounting grooves (26) of the first and second cover plates (21, 22), respectively, and placing the second body plate (31) between adjacent battery cells (41);

releasing the pretension force so that at least a portion of the protrusions (32) are located within the corresponding mounting grooves (26), and the protrusions (32) abut against the bottom walls (262) of the corresponding mounting grooves (26) so as to connect the first cover plate (21) and the second cover plate (22) in the height direction (Z) by the connecting member (3).