CN112736336A

CN112736336A - Battery cover plate assembly, power battery, battery module and automobile

Info

Publication number: CN112736336A
Application number: CN201911031173.9A
Authority: CN
Inventors: 程晗; 罗文�; 黄达; 王信月
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-10-28
Filing date: 2019-10-28
Publication date: 2021-04-30

Abstract

The invention provides a battery cover plate assembly, a power battery, a battery module and an automobile. The battery cover plate component comprises a cover plate, a pole and a leading-out piece. The pole is used for being electrically connected with an electrode terminal of the power battery, penetrates through the cover plate and protrudes outwards from the outer surface of the cover plate. The leading-out piece is fixed on the cover plate and is electrically connected with the pole, and is used for being connected to a module connecting piece of the battery module so as to realize electrical connection between the pole and the module connecting piece. According to the invention, the stress and strain generated by the module connecting sheet when being impacted can be directly transferred to the cover plate through the leading-out piece, so that the risk of sealing failure of the pole and even falling of the pole caused by the fact that the stress and strain are completely concentrated on the pole is avoided. In addition, the limitation of pole materials on the selection of the module connecting sheet can be eliminated, the module connecting sheet can be made of materials with better conductivity, and the improvement of the power and the quick charging capability of the battery module is facilitated on the premise that the occupied space of the module connecting sheet is not increased.

Description

Battery cover plate assembly, power battery, battery module and automobile

Technical Field

The invention relates to the technical field of batteries, in particular to a battery cover plate assembly, a power battery, a battery module and an automobile.

Background

Fig. 1 shows a sunken ceramic post structure for a power cell. The pole 20 protrudes outward from the cap plate 10. A ceramic insulating ring 21 is fitted over the pole 20 and is connected to the cover plate 10 by a butterfly-shaped transition ring 22. The inner side of the transition ring 22 is also provided with a rubber sealing ring 23 surrounding the pole 20 for sealing. The ceramic pole column structure has the advantages of long service life, high temperature resistance, no normal stress, reliable sealing and the like, and all sealing is realized in a welding mode.

When the battery module is formed, module connecting sheets between different power batteries are directly welded on the end face of the pole 20. The stress and strain generated when the module connecting piece is impacted are transmitted to the cover plate 10 through the pole 20, the ceramic insulating ring 21 and the transition ring 22. For process reasons, the transition ring 22 is usually made of 1-series aluminum, which has a low strength. While the pole 20 is in rigid contact with the cover plate 10 only at the transition ring 22. Therefore, when the stress and strain are too large, such a ceramic pole structure is prone to deformation failure at the transition ring 22, with the risk of failure of the seal of the pole 20, and even the pole 20 falling out.

In addition, the poles of the unit cells (e.g., lithium batteries) are typically aluminum. Due to the properties of metals, welding between different metals by conventional laser welding is not possible. Therefore, most of the inter-module connecting sheets are made of aluminum so as to be conveniently connected with aluminum poles. The development trend of the battery module is high power and rapid charging capability. This requires increasing the conductivity of the module connector, for example by increasing the volume and cross-sectional area or by selecting a more conductive material. However, the space design of the battery module is more and more compact, the space for the module connecting pieces to be placed is more and more limited, and it is difficult to provide the module connecting pieces having a larger volume and a larger sectional area. And other conductive materials are not convenient to be welded and connected with the pole. Thereby limiting the development of the battery module.

Therefore, a battery cover plate assembly, a power battery, a battery module and an automobile are needed to at least partially solve the above problems.

Disclosure of Invention

In this summary, concepts in a simplified form are introduced that are further described in the detailed description. This summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

To at least partially solve the above problems, according to a first aspect of the present invention, there is provided a battery cover plate assembly for a power battery, the battery cover plate assembly including:

a cover plate;

the pole column is used for being electrically connected with an electrode terminal of the power battery, penetrates through the cover plate and protrudes outwards from the outer surface of the cover plate; and

the leading-out piece is fixed on the cover plate and electrically connected with the pole, and the leading-out piece is used for being connected to a module connecting sheet of the battery module so as to realize electrical connection between the pole and the module connecting sheet.

According to the battery cover plate component, the power battery with the battery cover plate component can form the battery module in a mode that the module connecting sheet is connected to the leading-out piece, so that stress and strain generated by the module connecting sheet when the module connecting sheet is impacted can be directly transmitted to the cover plate through the leading-out piece, and the risk that the sealing failure of the pole and even the falling of the pole are caused because the stress and the strain are completely concentrated on the pole is avoided. In addition, the limitation of pole material on the material selection of the module connecting sheet can be eliminated, and the module connecting sheet only needs to be matched with the material of the leading-out piece. Therefore, the module connecting sheet can be made of a material with better conductivity, and the power and the quick charging capacity of the battery module can be improved on the premise of not increasing the occupied space of the module connecting sheet.

Optionally, the lead-out member comprises:

the leading-out piece is made of a conductive material, is connected to the pole and is used for being connected with the module connecting piece; and

the lead-out piece is fixedly connected with the partition plate, and the partition plate is fixedly connected with the cover plate.

Optionally, a slot is formed in the partition plate, a buckle and a clamping position are respectively arranged on the partition plate and the leading-out piece, and one end of the leading-out piece is inserted into the slot and is fixedly connected with the partition plate through the matching of the buckle and the clamping position.

Optionally, the lead-out piece includes a first conductive portion connected to the pole and a second conductive portion for connecting with the module connecting piece, the first conductive portion is made of the same material as the pole, and/or the second conductive portion is made of the same material as the module connecting piece.

Optionally, the material of the first conductive part and the second conductive part are respectively made of different materials, and the first conductive part and the second conductive part are connected by welding means of friction welding, soldering, EMPT welding or explosion welding to form the lead-out sheet.

Optionally, a welding positioning hole is formed in the position, connected with the module connecting sheet, of the leading-out sheet.

Optionally, the leading-out piece is provided with a first through hole, and the pole column penetrates through the first through hole to be connected with the leading-out piece.

Optionally, one of the partition and the cover plate is provided with a protrusion and the other of the partition and the cover plate is provided with a recess, the protrusion extending into the recess.

Optionally, the concave part or the convex part is arranged on the partition board close to the position of the lead-out piece connected with the module connecting piece.

Optionally, the separator is bonded to the cover plate by structural glue.

Optionally, a glue groove is formed in a side surface, facing the cover plate, of the partition plate, and the structural glue is at least partially arranged in the glue groove.

Optionally, the cover plate is provided with a second through hole, and the pole penetrates through the second through hole.

According to the second aspect of the invention, a power battery is also provided, and the power battery comprises any one of the battery cover plate assemblies as described above.

According to a third aspect of the invention, a battery module is further provided, the battery module comprises at least two power batteries, and the power batteries are electrically connected with each other by connecting module connecting sheets to the leading-out piece.

According to a fourth aspect of the present invention, an automobile is further provided, wherein the automobile comprises the power battery or the battery module.

Drawings

The following drawings of embodiments of the invention are included as part of the present invention for an understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, there is shown in the drawings,

FIG. 1 is a sectional view of a ceramic pole for a power battery;

FIG. 2 is a schematic cut-away view of a battery cover plate assembly according to a preferred embodiment of the present invention;

FIG. 3 is a perspective view of a separator plate of the lead-out member of the battery cover plate assembly shown in FIG. 2;

FIG. 4 is another angular perspective view of the battery cover plate assembly shown in FIG. 3; and

fig. 5 is an assembly view of the lead-out member of the battery cover shown in fig. 2.

Description of reference numerals:

battery cover plate subassembly: 100, cover plate: 10. 110 of a chemical formula

Convex part: 111 pole: 20. 120 of a plant

Ceramic insulating ring: 21. 121 transition ring: 22. 122 are provided

Rubber sealing ring: 23. 123 leading-out piece: 130

Leading out a sheet: 140 first conductive part: 141

A second conductive portion: 142 first via: 143

Welding positioning holes: 144 insertion part: 145

Blocking out: 146, partition plate: 150

And (3) rib bulging: 151 slot: 152

Buckling: 153 second through-hole: 154

Concave part: 155 glue groove: 156

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that embodiments of the invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in detail so as not to obscure the embodiments of the invention.

In the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

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

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the following description, a detailed structure will be presented for a thorough understanding of embodiments of the invention. It is apparent that the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art.

The present invention provides a battery cover plate assembly for a battery, particularly a power battery. The following detailed description is made with reference to the accompanying drawings.

As shown in fig. 2, a battery cover plate assembly 100 according to a preferred embodiment of the present invention includes a cover plate 110 and a terminal post 120. When applied to a power battery, the cover plate 110 is connected to an outer casing of the power battery, which covers an opening of the outer casing to form a closed space for accommodating a battery cell. The terminal post 120 is used to electrically connect with an electrode terminal of the battery cell. The pole post 120 penetrates the cover plate 110 and protrudes outward from the outer surface of the cover plate 110 to facilitate electrical connection of the power battery with other devices.

Preferably, in the present embodiment, a ceramic insulating ring 121 is sleeved on the pole post 120 to insulate and separate the pole post 120 from the cover plate 110. A butterfly-shaped transition ring 122 is disposed between the ceramic insulating ring 121 and the lower cover plate 110. The inside of the transition ring 122 is also provided with a rubber sealing ring 123 to seal at the location of the pole 120. In other words, the battery cover plate assembly 100 according to the present embodiment adopts a structure of a ceramic post, which has advantages of long life, high temperature resistance, no existence of normal stress, all sealing achieved by welding, and thus reliable sealing. However, other poles, such as riveted poles or injection moulded poles, may also be used for the battery cover plate assembly according to the invention. The invention does not limit the concrete structural form of the pole.

Further, the battery cover plate assembly 100 according to the present invention further includes a lead-out member 130. The lead-out member 130 is fixed to the cover plate 110 and electrically connected to the pole 120. When a plurality of single power batteries constitute a battery module, a module connecting tab for electrical connection between the power batteries may be electrically connected with the post 120 via the lead-out member 130, rather than being directly physically connected to the post 120. Thus, when the module strap is impacted, a substantial portion of the stresses and strains it generates may be transferred through the lead-outs 130 to the cover plate 110 without being entirely concentrated at the transition ring 122. The risk of failure due to excessive stress and strain experienced by the transition ring 122 can be effectively avoided, and the pole 120 can maintain structural integrity when impacted.

In addition, the extraction member 130 can be used to eliminate the limitation of the material of the pole 120 on the material selection of the module connecting sheet. Typically, the post 120 is aluminum. When the module connecting sheet is also made of aluminum, the whole lead-out member 130 may be made of aluminum so as to be welded to the post 120 and the module connecting sheet by conventional laser welding, thereby facilitating manufacturing.

While the leadouts 130 may be constructed as composite materials when other materials are used for the module connecting tabs, such as copper. For example, the part of the lead-out member 130 that is connected to the pole 120 is made of aluminum, while the part that is connected to the module connecting plate is made of a material that is suitable for a welded connection with the module connecting plate, which may be, for example, the same material as the module connecting plate. Therefore, the connection of the leading-out piece 130 with the pole 120 and the module connecting piece can be realized by adopting conventional laser welding, and the existing production process is not influenced. Simultaneously, the material selection of module connection piece is more nimble. For example, a material with better conductivity can be selected, and the conductivity of the module connecting sheet is enhanced on the premise of not increasing the volume and the sectional area of the module connecting sheet, so that the power of the battery module is improved, and the quick charging capability is realized.

The lead-out member 130 may be mounted before the housing process along with the incoming material of the cap plate 110, or may be additionally mounted as a fitting as needed when assembling the battery module, and thus, the assemblability is good.

Preferably, as shown in fig. 2 and 5, in the present embodiment, the lead-out member 130 is configured to include two parts of a lead-out piece 140 and a separator 150. The lead-out piece 140 is used for being connected with the pole 120 and the module connecting piece respectively. Separator 150 is manufactured as a separate component from tab 140 and is integrally and fixedly attached to tab 140 during assembly and for fixedly attaching to cover plate 110.

With such a structure, the electrical connection with the pole 120 and the module connecting sheet and the fixed connection with the cover plate 110 can be simultaneously realized, and the respective structures and materials of the leading-out sheet 140 and the partition plate 150 can be flexibly designed according to specific functions. For example, the tab 140 may be made of a conductive material suitable for soldering with the post 120 and the module connecting tab, respectively. The separator 150 may be made of a polymer material with high strength, stable chemical properties, simple molding, long service life, and environmental friendliness, such as PPS, fluoroplastic, or the like. In addition, according to actual needs, additives (for example, carbon black) with different components and proportions can be added to the polymer material constituting the separator 150 to perform different auxiliary functions such as insulation, conduction or conduction but certain resistance.

The tab 140 and the separator 150 are each configured in a substantially sheet-like structure. The two are preferably fixedly connected together in a plug-in manner by means of a snap-in and slot arrangement. Specifically, as shown in fig. 3 and 5, the partition 150 is configured substantially in a rectangular shape, and an upper surface thereof is provided with a rib 151 protruding upward at a pair of edges in a length direction. The opposite inner sides of the ribs 151 are provided with grooves 152 extending in the length direction. The groove 152 extends to one end of the partition 150 and communicates with the outside. The tab 140 is inserted into the groove 152 at this end in the insertion direction D. Thus, the tab 140 and the separator 150 are held relatively fixed in the width direction of the separator 150 and in the direction perpendicular to the separator 150. The grooves 152 may also be referred to as slots 152.

Preferably, the thickness of the edge of the tab 140 in the length direction is adapted to the width of the insertion groove 152 to form the insertion portion 145 inserted into the insertion groove 152. For example, the tab 140 may be configured to have an overall thickness that is compatible with the width of the slot 152; or may be tapered at the edges to accommodate the width of the slot 152 so that other locations of the tab 140 may have sufficient thickness to facilitate connection, such as by welding, with the module connecting tab and post 120.

Preferably, as shown in fig. 3, the separator 150 is also provided with a blocking portion 157 at the other end opposite to the end where the lead tab 140 is inserted. The stop 157 may prevent further movement of the tab 140 relative to the separator 150 in the insertion direction D after the tab 140 is inserted into position. Preferably, the blocking portion 157 may be constructed in the same structure as the rib 151 so as to be molded simultaneously with the rib 151. Of course, in other embodiments, the blocking portion may be formed by disposing an end of the groove 152 away from the insertion end of the tab 140 in a closed manner.

Preferably, as shown in fig. 3 and 5, the partition 150 is provided with a catch 153 at a position near an end where the lead-out piece 140 is inserted, and accordingly, the lead-out piece 140 is provided with a detent 146 at a corresponding position. After the tab 140 is inserted into position, the catch 153 and detent 146 cooperate to prevent relative movement of the tab 140 and spacer 150 in the direction opposite insertion direction D. Thus, the tab 140 and the separator 150 are kept relatively fixed in the longitudinal direction of the separator 150 (i.e., the insertion direction D). The tab 140 is fixedly connected to the partition 150. Of course, the detent may be provided on the partition 150 and the catch may be provided on the tab 140.

The partition board 150 and the lead-out sheet 140 are fixed by the snap and the slot, which has the advantages of low cost, simple process, high reliability when being stressed for a long time, etc. However, it is understood that other connection means, such as integral injection molding, other forms of physical snap/groove, screw/bolt connection, chemical bonding, special welding, etc., and assembly means are also possible. The invention does not limit the concrete connection mode of the leading-out sheet and the clapboard.

In the present embodiment, the separator 150 is fixedly coupled to the cap plate 110 by means of structural adhesive bonding. As shown in fig. 4, preferably, the surface of the spacer 150 facing the cap plate 110 is provided with a glue groove 156 extending along the edge of the spacer 150. During assembly, the tab 140 and the spacer 150 are fixed to each other, the structural adhesive is filled in the adhesive groove 156 of the spacer 150, and the tab 130 is integrally bonded to the surface of the cover plate 110. And then the connection between the lead-out piece 140 and the pole post 120 is completed. The glue groove 156 is arranged, so that more structural glue can be contained, and the bonding capability is enhanced.

Preferably, as shown in fig. 2 and 4, the cover plate 110 is provided with a protrusion 111, and the separator 150 is provided with a recess 155 at a position corresponding to the protrusion 111. When the separator 150 is bonded to the cover plate 110, the protrusions 111 extend into the recesses 155. Therefore, the partition board 150 can be correctly positioned quickly, and the assembly and the production are convenient. Of course, the convex portion may be provided on the partition 150 and the concave portion may be provided on the cover plate 110.

The protrusion 111 and the recess 155 may have adapted shapes, e.g. have a circular, elliptical or polygonal cross section, etc. to better fit. Two or more of the convex portions 111 and the concave portions 155 may be provided in a dispersed manner. In addition, the convex portion 111 and the concave portion 155 are preferably provided near the position of the tab 140 to which the module connecting piece is connected. This ensures proper positioning and better sharing of stresses and impacts, reducing the transfer of stresses and impacts to the post 120.

The spacer 150 (i.e., the lead-out member 130) is fixed to the cover plate 110 by means of structural adhesive bonding, which is simple in process, low in cost, high in strength, aging-resistant, fatigue-resistant, and capable of bearing a large load. However, in other embodiments, the lead-out member 130 may be fixed to the cover plate 110 by other means such as a snap/groove or rivet fixing.

The tab 140 is preferably connected to the post 120 and the module connecting tab by welding, such as laser welding. As described above, preferably, as shown in fig. 2 and 5, the lead-out piece 140 may include the first conductive portion 141 connected with the pole post 120 and the second conductive portion 142 for connection with the module connecting piece. The first conductive part 141 is made of a material (preferably, the same metal material) suitable for being welded with the post 120. The second conductive portion 142 is made of a material (preferably the same metal material) suitable for solder connection with the module connecting pad.

Typically, the post 120 is made of aluminum, and therefore, aluminum may be used for the first conductive portion 141. When the module connecting pad is made of aluminum, the second conductive portion 142 may also be made of aluminum. In this case, the tab 140 may be integrally formed of aluminum.

When the module connecting pad is made of other materials, such as copper, the second conductive portion 142 may be made of copper. In this case, the first conductive portion 141 may be made of aluminum, and the second conductive portion 142 may be made of copper. The first conductive portion 141 and the second conductive portion 142 may then be connected by welding such as friction welding, soldering, EMPT welding or explosion welding or other composite forming methods to form the tab 140. Therefore, the battery cover plate component is wider in applicability, and the material selection of the module connecting plate can be more flexible.

Preferably, as shown in fig. 2 and 5, the lead-out sheet 140 is provided with a first through hole 143 at the first conductive part 141. When assembled, the post 120 first extends through the first through hole 143, and then the post 120 is welded to the tab 140. Therefore, the contact area between the two can be increased, and the firmness of welding is improved. Preferably, a second through hole 154 may be provided on the partition 150 at a position corresponding to the first through hole 143. The post 120 may extend through the second through-hole 154 to facilitate welding with the lead tab 140. While also enhancing the fixing effect of the partition 150.

Preferably, the second conductive part 142 of the tab 140 is provided with a welding positioning hole 144, which can be used for positioning the CCD when the tab 140 is welded with the module connecting sheet, so as to improve the welding accuracy.

According to the second aspect of the invention, a power battery is also provided. The power battery comprises the battery cover plate assembly.

According to a third aspect of the present invention, there is also provided a battery module. The battery module comprises at least two power batteries. The power batteries are electrically connected with each other in a mode of connecting the module connecting pieces to the leading-out piece.

According to a fourth aspect of the present invention, there is also provided an automobile comprising the above power battery or battery module.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Terms such as "disposed" and the like, as used herein, may refer to one element being directly attached to another element or one element being attached to another element through intervening elements. Features described herein in one embodiment may be applied to another embodiment, either alone or in combination with other features, unless the feature is otherwise inapplicable or otherwise stated in the other embodiment.

The present invention has been described in terms of the above embodiments, but it should be understood that the above embodiments are for purposes of illustration and description only and are not intended to limit the invention to the scope of the described embodiments. It will be appreciated by those skilled in the art that many variations and modifications may be made to the teachings of the invention, which fall within the scope of the invention as claimed.

Claims

1. A battery cover plate assembly for a power battery, the battery cover plate assembly comprising:

a cover plate;

2. The battery cover plate assembly of claim 1, wherein the lead-out member comprises:

3. The battery cover plate assembly according to claim 2, wherein a slot is formed in the partition plate, a buckle and a detent are respectively formed in the partition plate and the lead-out piece, and one end of the lead-out piece is inserted into the slot and is fixedly connected with the partition plate through the matching of the buckle and the detent.

4. The battery cover plate assembly of claim 2, wherein the tab comprises a first conductive portion connected to the post and a second conductive portion for connection with the module connector tab, the first conductive portion being of the same material as the post and/or the second conductive portion being of the same material as the module connector tab.

5. The battery cover plate assembly of claim 4, wherein the material of the first conductive portion and the second conductive portion are made of different materials, respectively, and the first conductive portion and the second conductive portion are connected by welding such as friction welding, soldering, EMPT welding, or explosion welding to form the tab.

6. The battery cover plate assembly of claim 2, wherein the tab is provided with a welding positioning hole at a position where the tab is connected to the module connecting tab.

7. The battery cover plate assembly of claim 2, wherein the tab is provided with a first through hole, and the pole post passes through the first through hole to be connected with the tab.

8. The battery cover plate assembly of claim 2, wherein one of the separator plate and the cover plate is provided with a protrusion and the other of the separator plate and the cover plate is provided with a recess, the protrusion extending into the recess.

9. The battery cover plate assembly of claim 8, wherein the recess or the protrusion is disposed on the separator plate near a location of the tab to which the module connecting tab is connected.

10. The battery cover plate assembly of claim 2, wherein the separator plate is bonded to the cover plate by structural glue.

11. The battery cover plate assembly of claim 10, wherein a side of the separator plate facing the cover plate is provided with a glue groove, and the structural glue is at least partially disposed in the glue groove.

12. The battery cover plate assembly of claim 2, wherein the cover plate is provided with a second through hole through which the terminal post passes.

13. A power cell comprising a cell cover plate assembly according to any one of claims 1 to 12.

14. A battery module, characterized in that the battery module comprises at least two power cells according to claim 13, the power cells being electrically connected to each other by means of a module connecting tab connected to the lead-out member.

15. An automobile, characterized in that the automobile comprises the power battery according to claim 13 or the battery module according to claim 14.