CN113054284A

CN113054284A - Battery module, corresponding method and battery pack

Info

Publication number: CN113054284A
Application number: CN202110294857.9A
Authority: CN
Inventors: 胡晓玮; 刘冠伟
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-06-29

Abstract

The invention relates to a battery module (100) comprising at least: a plurality of single batteries (10) which are arranged in a stacked manner, each single battery having a positive tab (2), a negative tab (3) and at least one heat-conducting tab (4) which is connected to a current collector in a cell (1) of the single battery (10); a heat-conducting carrier plate (20) which is configured to support the battery cells (10) and in which the heat-conducting tabs (4) are in contact, wherein the heat-conducting carrier plate (20) is formed in multiple parts from insulating supports (21) on both sides and a plurality of heat-conducting webs (22) in the middle. The invention also relates to a corresponding assembly method and a battery pack (1000). The heat conduction efficiency can be effectively improved, and the flow capacity can be enhanced.

Description

Battery module, corresponding method and battery pack

Technical Field

The present invention relates to a battery module. The invention also relates to a corresponding method for assembling a battery module and a corresponding battery pack.

Background

In recent years, with the increasing attention on environmental protection, battery modules composed of single batteries, especially lithium ion batteries, and battery packs further composed of battery modules are receiving more and more attention as power sources in the fields of vehicles, consumer electronics, and the like, and the market places increasingly higher demands on the power performance, safety, and service life of battery products.

As known from the prior art, a battery product is very sensitive to the operation temperature, can be charged and discharged with high efficiency and keeps good performance only in a proper temperature range, wherein, the aging speed and the thermal resistance increasing speed of the battery are accelerated by the excessively high operation temperature, the service life is shortened, and even the thermal runaway and other problems of the battery are caused; while too low an operating temperature causes a decrease in conductivity of the battery electrolyte, a decrease in ionic activity, and a decrease in battery capacity.

However, in the conventional battery product, heat needs to be conducted through a long heat conduction path, such as a cell internal packaging structure, a cell aluminum plastic film, a structural adhesive, and the like, which causes a series of problems of a large amount of heat conduction media, low heat conduction efficiency, and the like, thereby causing the battery product not to operate well in an optimal temperature range. In addition, the conventional battery product has disadvantages of high cost and low overcurrent capacity due to many components and a complicated structure.

Disclosure of Invention

Therefore, it is an object of the present invention to provide an improved battery module that is capable of simplifying a heat conduction path and improving heat conduction efficiency, and enhancing mechanical strength and overcurrent capacity of the battery module, thereby operating the battery module in an optimum temperature range as much as possible and improving power performance and lifespan of the battery module. In addition, the battery module according to the present invention can be manufactured and assembled simply and cost-effectively. The invention also aims to provide a corresponding method for assembling the battery module and a corresponding battery pack.

According to a first aspect of the present invention, there is provided a battery module including at least:

-a plurality of cells arranged one above the other, each cell having a positive tab, a negative tab and at least one thermally conductive tab connected to a current collector in a cell of the cell;

-a thermally conductive support plate configured for supporting the battery cells, the thermally conductive tabs contacting the thermally conductive support plate,

wherein the heat-conducting support plate is formed in multiple parts from insulating supports on both sides and a plurality of heat-conducting webs in the middle.

Compared with the prior art, the single battery in the battery module can utilize the at least one heat conduction tab connected with the current collector in the battery core to directly lead out the heat inside the battery from the single battery or directly lead the heat into the single battery along the extending direction of the current collector, so that the heat conduction path can be obviously simplified, and the heat conduction efficiency can be improved. The contact of the heat conduction lug and the heat conduction connecting sheet of the heat conduction supporting plate can increase the heat conduction area and further improve the heat conduction efficiency, so that each single battery in the battery module can always run in the optimized temperature range. In addition, the heat conduction tab is electrified due to the connection with the current collector in the battery core, and the insulating support of the heat conduction support plate can prevent leakage current and ensure the overcurrent capacity of the battery module.

According to an exemplary embodiment of the invention, the holder is made of a plastic material; and/or the heat-conducting connecting piece is made of a metal material, in particular aluminum.

According to an exemplary embodiment of the present invention, the support is provided with a thermal riveting column structure, and the heat conducting connecting sheet is provided with a corresponding positioning hole, and the support and the heat conducting connecting sheet are fixedly connected through the mutual matching of the thermal riveting column structure and the positioning hole.

According to an exemplary embodiment of the invention, the thermally conductive tab penetrates the thermally conductive support plate via a gap between adjacent thermally conductive connection tabs; and/or the heat-conducting tab is attached to the heat-conducting connecting sheet in an L-shaped bending mode; and/or the heat-conducting lug and the heat-conducting connecting sheet are fixedly connected with each other, particularly by welding.

According to an exemplary embodiment of the invention, the number of thermally conductive connection tabs corresponds to the number of cells; and/or the width of the gap between adjacent heat conducting connecting sheets is set according to the requirements of creepage distance and electric gap.

According to an exemplary embodiment of the invention, the thermally conductive tab extends over substantially the entire longitudinal extension of the battery cell; and/or the individual cells are each provided with heat-conducting tabs on two opposing longitudinal sides, and the battery module accordingly has two heat-conducting support plates; and/or, the battery module further comprises an end top plate.

A second aspect of the invention provides a method for assembling a battery module according to the invention, the method including at least the steps of:

s1: providing a heat-conducting support plate, which is formed in multiple parts by insulating supports on both sides and a plurality of heat-conducting connection pieces in the middle;

s2: providing a plurality of single batteries, wherein each single battery is provided with a positive electrode lug, a negative electrode lug and at least one heat conduction lug, and the heat conduction lugs are connected with a current collector in a battery core of each single battery;

s3: arranging the plurality of unit cells on top of each other, and contacting the thermally conductive tabs to the thermally conductive support plate.

According to an exemplary embodiment of the present invention, in step S1, a heat stake structure provided on the bracket is inserted into a corresponding positioning hole of the heat conductive connection sheet and deformed by a hot pressing process.

According to an exemplary embodiment of the invention, the method further comprises a step S4, in which the thermally conductive tab is bent in an L-shape and is fitted, in particular welded, to the thermally conductive connecting piece.

A third aspect of the present invention provides a battery pack including at least one battery module according to the present invention and a heat transfer device in contact with the heat transfer tabs of the battery module and configured to conduct heat out of and/or into the battery module.

According to an exemplary embodiment of the invention, the heat conducting device is configured as a liquid-cooled plate; and/or an insulating film, in particular a polycarbonate insulating film, is applied to the heat conducting device between the heat conducting device and the heat conducting tab.

Drawings

The principles, features and advantages of the present invention may be better understood by describing the invention in more detail below with reference to the accompanying drawings. The drawings comprise:

fig. 1 shows a schematic view of a unit cell of a battery module according to an exemplary embodiment of the present invention;

fig. 2 illustrates an exploded view of a battery module according to an exemplary embodiment of the present invention;

fig. 3 illustrates a schematic view of a thermally conductive support plate of a battery module according to an exemplary embodiment of the present invention;

fig. 4 illustrates an assembly view of a battery module according to an exemplary embodiment of the present invention;

fig. 5 is a flowchart illustrating a method for assembling a battery module according to an exemplary embodiment of the present invention;

fig. 6 shows a schematic diagram of a battery pack according to an exemplary embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and exemplary embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of the invention.

Fig. 1 shows a schematic view of a unit cell 10 of a battery module 100 according to an exemplary embodiment of the present invention. Here, the battery module 100 is used in a battery pack of a vehicle and supplies electric energy as a power source, and the specific structure is shown in fig. 2. Here, the unit cell 10 is exemplarily configured as a soft pack lithium ion battery that can be repeatedly charged and discharged.

As shown in fig. 1, the unit battery 10 includes a cell 1, a positive electrode tab 2, and a negative electrode tab 3. Here, the battery cell 1 has, for example, a polymer housing suitable for soft-packed lithium ion batteries and a current collector in the polymer housing, which is configured to collect the currents generated by the battery active substances to form a large current output to the outside and is configured, for example, as a metal foil. Here, the positive tab 2 and the negative tab 3 are connected to respective ones of the current collectors and extend from the case so as to function as a positive electrode and a negative electrode of the unit battery 10.

As shown in fig. 1, the battery cell 10 also comprises at least one thermally conductive tab 4, which is likewise connected directly to the current collector in the battery cell 1 and extends out of the housing. It is conceivable here that the heat conducting tab 4 is constructed identically to the positive tab 2 and/or the negative tab 3, thereby simplifying the production process of the heat conducting tab 4. The thermally conductive tab 4 is illustratively made of aluminum. Due to the continuity of the current collector in the direction of extension and the high thermal conductivity, a rapid transfer of heat via the current collector and the thermally conductive tabs 4 is possible, as a result of which the temperature of the individual cells 10 can advantageously be rapidly regulated while simplifying the thermally conductive path and the individual cells 10 can always be operated in the desired temperature range. It should be noted that, since the heat conducting tab 4 is directly connected to the current collector, the heat conducting tab 4 is also charged.

Illustratively, the thermally conductive tabs 4 extend over substantially the entire longitudinal extension of the battery cells 10. Within the framework of the invention, the term "longitudinal extent" is understood to mean the extent of the relatively long sides of the battery cell 10. This makes it possible to achieve the largest possible heat exchange area of the heat-conducting tab 4 and to increase the heat-conducting efficiency.

Exemplarily, the individual cells 10 are provided with heat conducting tabs 4 on two opposing longitudinal sides, respectively, whereby the heat exchange area of the individual cells 10 can be further increased.

By way of example, it is also conceivable to provide any number of thermally conductive tabs 4 on either side of the battery cell 10, which is considered to be significant by the person skilled in the art.

Fig. 2 illustrates an exploded view of the battery module 100 according to an exemplary embodiment of the present invention.

As shown in fig. 2, the battery module 100 includes a plurality of unit cells 10 shown in fig. 1, which are arranged in a cell stack stacked on one another. Here, the unit cells 10 collectively supply electric energy to the outside in series and/or parallel by the connection of the respective positive electrode tab 2 and negative electrode tab 3.

As shown in fig. 2, the battery module 100 further includes a heat conductive support plate 20 configured to support the unit cells 10 in an assembled state so as to ensure structural stability of the battery module 100. The heat-conducting carrier plate 20 is formed in multiple parts from insulating supports 21 on both sides and a plurality of heat-conducting lugs 22 in the middle, the supports 21 being fixedly connected to the heat-conducting lugs 22. In this case, a gap is present between each two adjacent heat-conducting connecting tabs 22 of the heat-conducting support plate 20, through which gap the heat-conducting tabs 4 of the individual cells 10 pass through the heat-conducting support plate 20 during assembly and contact, in particular abut, the heat-conducting connecting tabs 22 of the heat-conducting support plate 20, so that the thermal contact area of the heat-conducting tabs 4 is further increased and the heat-conducting efficiency is increased. Here, since the support 21 is insulated, the conduction of electric charge to the battery module or other components of the battery pack via the thermally conductive tab 4 and the thermally conductive connecting sheet 22 is prevented, thereby preventing the occurrence of leakage current and ensuring the overcurrent capability of the battery module 100.

Illustratively, the bracket 21 is made of a plastic material. It is of course also conceivable that the holder 21 is manufactured from other insulating materials which are considered to be of interest to the person skilled in the art.

The thermally conductive connecting piece 22 is manufactured, for example, from a metallic material, in particular from aluminum. It is of course also contemplated that the thermally conductive tabs 22 are made of other thermally conductive materials that will be deemed significant by those skilled in the art.

For example, when the battery cells 10 are each provided with heat-conducting tabs 4 on two opposing longitudinal sides, the battery module 100 has two heat-conducting support plates 20 on the two longitudinal sides, respectively.

The number of thermally conductive connecting tabs 22 of the thermally conductive support plate 20 corresponds, by way of example, to the number of individual cells 10.

Illustratively, the width of the gap between each two adjacent heat conductive connection tabs 22 is set according to the requirements of the creepage distance and the electrical gap, thereby ensuring the electrical safety and stability of the battery module 100. The width of the gap can be determined from empirical or experimental data as a function of the creepage and clearance requirements.

As shown in fig. 2, the battery module 100 further illustratively includes two end top plates 30 that are disposed on both sides of the cell stack composed of the unit cells 10 and press the cell stack therebetween when assembled, thereby further improving the structural stability and mechanical strength of the entire battery module 100 and preventing the unit cells 10 located on the outer side from being damaged due to impact.

Fig. 3 shows a schematic view of the thermally conductive support plate 20 of the battery module 100 according to an exemplary embodiment of the present invention.

As shown in fig. 3, the heat conducting support plate 20 is composed of two insulating supports 21 on both sides and a plurality of heat conducting connecting pieces 22 in the middle, wherein the supports 21 are fixedly connected with the heat conducting connecting pieces 22. The individual thermally conductive connection pieces 22 may be configured differently from one another. The width of the heat-conducting connecting plate 22 can be determined in accordance with the width of the heat-conducting tab 4 to be attached. The length of the heat-conducting connecting piece 22 is greater than the length of the heat-conducting tab 4.

As shown in fig. 3, the carrier 21 is provided with a hot rivet pin structure 23, which is constructed in particular in one piece with the carrier 21, for example by injection molding. The thermally conductive attachment tab 22 is provided with a locating hole 24 corresponding to the hot rivet post structure 23. The fixed connection of the carrier 21 to the heat-conducting connecting plate 22 can be realized here by the cooperation of the rivet pin structure 23 and the positioning hole 24. The above-described fixed connection is achieved, for example, by deforming the hot rivet column structure 23 inserted into the positioning hole 24 through a hot pressing process. In addition, other connection means, such as adhesive bonding or scarf joining, which are considered to be expedient by the person skilled in the art, are also conceivable.

Fig. 4 illustrates an assembly view of the battery module 100 according to an exemplary embodiment of the present invention, which illustrates an assembled state of the battery module 100.

As shown in fig. 4, in the assembled state of the battery module 100, a frame is formed by the two opposing end top plates 30 and the at least one heat-conducting support plate 20, which surrounds and supports a cell stack consisting of a plurality of single cells 10. The thermally conductive tabs 4 of each cell 10 are respectively inserted through the thermally conductive support plate 20 via a gap between two adjacent thermally conductive connection tabs 22 of the thermally conductive support plate 20. In this case, at least a portion of the thermally conductive tab 4 is externally disposed at the bottom of the battery module 100.

Illustratively, the part of the heat-conducting tab 4 penetrating through the heat-conducting support plate 20 is attached to the heat-conducting connecting piece 22 by means of a tooling fixture in an L-shaped bent manner, thereby increasing the thermal contact area of the heat-conducting tab 4 and improving the heat-conducting efficiency. The thermally conductive tab 4 and the thermally conductive connecting piece 22 are fixedly connected to each other, for example, by welding, which enables high mechanical strength and structural stability of the battery module 100.

Fig. 5 shows a flowchart of a method for assembling the battery module 100 according to an exemplary embodiment of the present invention.

As shown in fig. 5, the method comprises at least the following steps:

s1: providing a heat-conducting support plate 20 which is formed in multiple parts from insulating supports 21 on both sides and a plurality of heat-conducting connecting plates 22 in the middle, wherein optionally a rivet pin structure 23 is provided on the support 21 and a positioning hole 24 corresponding to the rivet pin structure 23 is provided on the heat-conducting connecting plates, and after inserting the rivet pin structure 23 into the positioning hole 24, the rivet pin structure 23 is deformed by means of a hot-pressing process in order to fixedly connect the support 21 to the heat-conducting connecting plates 22;

s2: providing a plurality of single batteries 10, wherein each single battery is provided with a positive electrode tab 2, a negative electrode tab 3 and at least one heat conduction tab 4, and the heat conduction tabs are directly connected with a current collector in a battery core 1 of each single battery 10;

s3: the plurality of unit cells 10 are arranged one on top of the other, and the thermally conductive tabs 4 are passed through and in contact with the thermally conductive support plate 20 via gaps between adjacent thermally conductive tabs 22.

The method may optionally further comprise a step S4 in which the heat-conducting lugs are bent in an L-shape and applied to the respective heat-conducting webs 22. It is conceivable here to fixedly connect the heat-conducting tab 4 to the heat-conducting connecting lug 22 by means of a welding process.

Fig. 6 shows a schematic diagram of a battery pack 1000 according to an exemplary embodiment of the present invention.

As shown in fig. 6, the battery pack 1000 includes a plurality of battery modules 100 according to the present invention, which are connected to each other in series-parallel by respective positive and negative electrodes and supply electric power to the outside. The battery pack 1000 further includes a heat transfer device 200 at the battery pack level, which is configured to conduct heat out of the battery module 100 and/or to conduct heat into the battery module 100. Here, the heat conduction device 200 is in contact with or attached to the heat conduction tab 4 of the battery module 100. This forms a heat conduction path from the cell current collector of the battery module 100 to the heat conduction device 200 of the battery pack 1000 via the heat conduction tab 4, which is significantly simplified and greatly increases the heat conduction efficiency compared to the heat conduction path of a conventional battery pack. The heat conducting device 200 is here embodied as a liquid-cooled plate, which is produced in particular from metal.

For example, in order to prevent the electrical charge of the heat-conducting tab 4 from leaking out via the heat-conducting device 200, an insulating film, in particular a Polycarbonate (PC) insulating film, which may have a thickness of 0.2mm, for example, is applied to the heat-conducting device 200 between the heat-conducting device 200 and the heat-conducting tab 4. Furthermore, it is also conceivable to apply a thermally conductive silicone gel between the thermally conductive device 200 and the thermally conductive tab 4.

Exemplarily, when the unit batteries 10 of the battery module 100 are respectively provided with the heat conductive tabs 4 on the opposite longitudinal sides, the heat conductive devices 200 may be provided on both sides of the battery module 100 in order to improve the heat conductive efficiency as much as possible.

Illustratively, the battery pack 1000 may further include a temperature management system configured to monitor the temperature of the battery modules 100 in the battery pack and control the heat transfer device 200 to perform temperature regulation accordingly, so as to ensure that the battery modules 100 are always within a normal operating temperature range.

The preceding explanations of embodiments describe the invention only in the framework of said examples. Of course, the individual features of the embodiments can be freely combined with one another as far as technically expedient, without departing from the framework of the invention.

Other advantages and alternative embodiments of the present invention will be apparent to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative structures, and illustrative examples shown and described. On the contrary, various modifications and substitutions may be made by those skilled in the art without departing from the basic spirit and scope of the invention.

Claims

1. A battery module (100) comprising at least:

-a plurality of cells (10) arranged one above the other, each having a positive tab (2), a negative tab (3) and at least one thermally conductive tab (4) connected to a current collector in a cell (1) of the cell (10);

-a thermally conductive support plate (20) configured for supporting the battery cells (10), the thermally conductive tabs (4) contacting the thermally conductive support plate,

wherein the heat-conducting carrier plate (20) is formed in multiple parts from insulating supports (21) on both sides and from a plurality of heat-conducting webs (22) in the middle.

2. The battery module (100) according to claim 1, wherein the bracket (21) is made of a plastic material; and/or

The heat-conducting connecting sheet (22) is made of a metallic material, in particular aluminum.

3. The battery module (100) according to claim 1 or 2, characterized in that the support (21) is provided with a heat stake structure (23) and the heat conducting connection piece (22) is provided with a corresponding positioning hole (24), and the fixed connection of the support (21) and the heat conducting connection piece (22) is realized through the mutual cooperation of the heat stake structure (23) and the positioning hole (24).

4. The battery module (100) according to any one of the preceding claims, wherein the thermally conductive tabs (4) pass through the thermally conductive support plate (20) via a gap between adjacent thermally conductive tabs (22); and/or

The heat-conducting tab (4) is attached to the heat-conducting connecting sheet (22) in an L-shaped bending mode; and/or

The heat-conducting tab (4) and the heat-conducting connecting sheet (22) are fixedly connected to one another, in particular by welding.

5. The battery module (100) according to any one of the preceding claims, wherein the number of thermally conductive connection tabs (22) corresponds to the number of battery cells (10); and/or

The width of the gap between adjacent thermally conductive tabs (22) is set according to the creepage and clearance requirements.

6. The battery module (100) according to any one of the preceding claims, wherein the thermally conductive tabs (4) extend over substantially the entire longitudinal extension of the battery cells (10); and/or

The individual cells (10) are each provided with heat-conducting tabs (4) on two opposite longitudinal sides, and the battery module (100) has two heat-conducting support plates (20) in each case; and/or

The battery module (100) further includes an end top plate (30).

7. A method for assembling a battery module (100), which is the battery module according to any one of claims 1 to 6, the method comprising at least the steps of:

s1: providing a heat-conducting carrier plate (20) which is formed in multiple parts from insulating supports (21) on both sides and from a plurality of heat-conducting webs (22) in the middle;

s2: providing a plurality of single batteries (10), wherein each single battery is provided with a positive electrode tab (2), a negative electrode tab (3) and at least one heat conduction tab (4), and the heat conduction tabs are connected with current collectors in battery cores (1) of the single batteries (10);

s3: arranging the plurality of battery cells (10) on top of each other and contacting the heat conducting tabs (4) with the heat conducting support plate (20).

8. The method according to claim 7, characterized in that in step S1, hot rivet column structures (23) provided on the support (21) are inserted into corresponding positioning holes (24) of the thermally conductive connecting piece (22) and the hot rivet column structures (23) are deformed by a hot pressing process; and/or

The method further comprises a step S4 in which the heat-conducting tab (4) is bent in an L-shape and is applied, in particular welded, to the heat-conducting connecting sheet (22).

9. A battery pack (1000) comprising at least one battery module (100) according to any one of claims 1 to 6 and a heat conducting device (200) in contact with the heat conducting tabs (4) of the battery module (100) and configured for conducting heat out of the battery module (100) and/or into the battery module (100).

10. The battery pack (1000) of claim 9, wherein the heat conducting means (200) is configured as a liquid-cooled plate; and/or

An insulating film, in particular a polycarbonate insulating film, is applied to the heat-conducting device (200) between the heat-conducting device (200) and the heat-conducting tab (4).