CN218586265U - Battery pack - Google Patents

Abstract

The application relates to a battery pack, which comprises two battery monomers, wherein each battery monomer comprises a battery cell body, a pole and a connecting sheet, the pole is connected with the battery cell body, and the connecting sheet is used for connecting the two battery monomers. The single battery and the connecting sheet are configured, wherein one pole of one battery and one pole of the other battery are respectively and fixedly embedded in the same connecting sheet. The proposal can simplify the welding process during production, and does not put strict requirements on various dimensional parameters of the connecting sheet, thereby further simplifying the production process. And simultaneously, the energy consumption is also reduced.

Description

Battery pack

Technical Field

The application relates to the field of batteries, in particular to a battery pack.

Background

In the prior art, as shown in fig. 6 and 7, a pressing plate 26 is disposed on a surface of a cell casing 250, and the pressing plate and a terminal jointly form a tab, and are electrically connected to other devices through the tab. In this embodiment, the pressing plate 26 is made of a metal material, and the pressing plate 26 is also conductive, so that when other devices are connected externally, the pressing plate 26 can increase the contact area, thereby having good electrical conductivity.

With the development of the technology, a plurality of battery cells are often required to be connected in series and in parallel to form a battery pack. A common method for combining a plurality of battery cells in the prior art is to connect a connecting plate made of aluminum between two battery cells, specifically, the connecting plate is fixedly connected to two tabs of two battery cells, respectively, so as to form a current path between the tabs of two battery cells. Generally, the connecting sheet and the tab are welded and fixed by laser welding. Specifically, as shown in fig. 7 and 8, the tab includes a pressing plate 26, and a method generally adopted in the prior art is to first place a connecting plate on the pressing plates 26 of two battery cells, and then use a laser penetration welding technique to weld and fix the connecting plate, the pressing plate 26 and the terminal post at the same time after penetrating the connecting plate with laser. However, the thickness of the connecting piece is large because the connecting piece is subjected to a large overcurrent, which results in that the laser welding device must penetrate the connecting piece under high-power conditions. But be subject to the performance of current laser welding equipment, the thickness of connection piece on the one hand can not be too big otherwise unable laser welding, even on the other hand adjusts laser welding equipment to high-power operating mode, the penetration that has during the welding is also lower, can appear the relatively poor problem of welding department reliability equally.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a group battery, this group battery has good connection reliability to easily welding has solved among the prior art and has used the relatively poor problem of welding department reliability behind laser welding utmost point ear and the connection piece.

In order to achieve the above purpose, the solution provided by the present application is as follows:

the application provides a group battery, including two battery monomers, the battery monomer includes: a cell body; the pole is connected with the battery cell body;

the pole column protrudes outwards relative to the outer surface of the battery cell body around the pole column;

the battery pack further includes: the connecting sheet is used for connecting the two battery cells;

the single battery and the connecting sheet are configured in such a way that one of the pole columns of one of the single batteries and one of the pole columns of the other single battery are respectively fixedly embedded in the same connecting sheet.

Through the technical scheme, because the pole is embedded in the connecting sheet, the penetrating distance of laser is less than the thickness of the connecting sheet during welding, and therefore the power required by the laser welding equipment during working is reduced. And just because the distance that the laser needs to pierce through has been reduced, also helps increasing the welding depth, promotes the connection reliability. Meanwhile, the thickness of the connecting piece is not limited by the performance of the laser welding equipment any longer, and the connecting piece can be designed to be thicker so as to bear larger overcurrent.

In the prior art, the requirement for the planar fit between the connecting piece and the pressure plate 26 is high, and the essential reason is to avoid that the welding reliability is too poor due to the overlarge gap between the connecting piece and the pressure plate 26. After this scheme of adoption, utmost point post inlays and locates in the connecting piece, only need utmost point post and connecting piece on be used for installing the hole or the groove matching of utmost point post can, no longer require the surface that connecting piece and electricity core body contacted must have the plane laminating degree of high accuracy. Moreover, in the preferred embodiment, the pressing plate 26 is no longer an essential component, the number of parts of the battery pack is reduced after the pressing plate 26 is eliminated, which contributes to reducing the production cost, and the height of the battery cell is reduced after the pressing plate 26 is eliminated, which contributes to improving the energy density of the battery cell.

As a preferred embodiment, the connecting sheet is provided with at least two connecting holes penetrating through the upper side and the lower side of the connecting sheet, and the pole is fixedly connected to the connecting holes.

In the preferable scheme, because the connecting hole is a through hole, the welding equipment can be directly contacted with the pole during welding, so that the pole in the connecting hole can be fixedly connected with the connecting hole by using a simple process method, for example, the connection can be realized by using a simpler laser seam welding process. Because the battery pack provided by the preferred scheme does not adopt a laser penetration welding process during production, various technical defects in the prior art caused by the adoption of laser penetration welding are directly avoided, the power required by laser welding equipment can be further reduced, and the process flow is greatly simplified. Furthermore, when the optimal scheme is adopted, the welding result can be directly observed in the welding process, and the welding result needs to be detected by a destructive detection method in the prior art, so that the scheme is favorable for improving the yield.

In a preferred embodiment, one side surface of the connecting sheet is provided with at least two grooves, and the pole is fixedly connected with the grooves

In a preferred embodiment, the pole is welded and fixed with the connecting hole.

As a preferred embodiment, the battery cell further includes an insulating sheet, and the insulating sheet is clamped between the connecting sheet and the cell body.

As a further preferred embodiment, the insulating sheet comprises: the upper surface of the insulating sheet body is attached to the lower surface of the connecting sheet, and the lower surface of the insulating sheet body is attached to the surface of the battery cell body; the insulating piece mounting hole is arranged on the insulating piece body, and the pole is arranged in the insulating piece mounting hole in a penetrating mode.

In a preferred embodiment, the connecting piece is made of aluminum.

In a preferred embodiment, the upper end of the pole is lower than or flush with the upper end face of the connecting sheet.

As a preferred embodiment, the cell body includes: a cell shell; the pin is fixedly arranged in the battery cell shell; the substrate assembly is fixedly connected with the battery cell shell so as to enable the battery cell body to form a closed structure; the pole column sequentially penetrates through the pin and the substrate assembly and extends out of the substrate assembly.

In a further preferred embodiment, the pole sleeve is provided with a sealing ring, and the sealing ring is clamped between the substrate assembly and the pins.

Additional features and advantages of the present application will be described in detail in the detailed description which follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural view illustrating a battery pack provided in a first preferred embodiment of the present application after connection;

fig. 2 is a schematic structural diagram of a battery pack provided in a second preferred embodiment of the present application before connection;

fig. 3 is an exploded view of an assembly of one of the battery cells in a battery pack according to a second preferred embodiment of the present application;

FIG. 4 is a schematic view of the components of FIG. 3 in an enlarged scale;

FIG. 5 is a schematic structural diagram of an insulating sheet according to a second preferred embodiment of the present application;

fig. 6 is a schematic structural view illustrating a battery pack provided in a second preferred embodiment of the present application after connection;

fig. 7 is a schematic structural view illustrating a conventional battery pack before connection;

fig. 8 is a schematic structural view of a conventional battery pack after connection;

description of the reference numerals: 1. connecting sheets; 10. a groove; 11. a first connection hole; 12. a second connection hole; 20. a pole column; 201. a first pole column; 202. a second pole; 21. an insulating sheet; 210. an insulating sheet body; 211. an insulating sheet mounting hole; 22. a substrate assembly; 221. a substrate mounting hole; 23. a seal ring; 24. a pin; 241. a pin mounting hole; 25. a cell body; 250. a cell shell; 26. and (7) pressing a plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. The components of the embodiments of the present application, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

A preferred embodiment of a battery pack provided by the present application is shown in fig. 1 to 6, and the battery pack includes two battery cells and a connecting sheet 1 connected between the two battery cells. The single battery comprises a battery cell body 25 and a pole 20 connected with the battery cell body 25, the connecting sheet 1 is preferably a sheet-shaped part made of aluminum, and the connecting sheet 1 is used for bearing the overcurrent between the two single batteries so that the two single batteries can be connected with each other to form a battery pack. For the convenience of understanding, the present embodiment takes a battery pack formed by connecting two battery cells as an example, and only the adaptive transformation structure is needed in the case of having more battery cells. In this embodiment, for convenience of description, the pole 20 on the battery cell on the right side shown in fig. 2 is named as a first pole 201, the pole 20 on the battery cell on the left side shown in fig. 2 is named as a second pole 202, and both the first pole 201 and the second pole 202 protrude upward relative to the surface of the cell body 25 to which they are connected, so that the first pole 201 and the second pole 202 can be embedded into the connecting sheet 1 to achieve a fixed connection with the connecting sheet 1.

In order to enable the first pole column 201 and the second pole column 202 to be embedded into the connecting sheet 1, in the first preferred embodiment, as shown in fig. 1, the lower surface of the connecting sheet 1 is provided with two grooves 10 adapted to the pole columns 20 in advance, and the pole columns 20 of two battery cells are respectively fixed in the two grooves 10 of the same connecting sheet 1, so that the pole columns 20 can be embedded into the connecting sheet 1. The advantage of this kind of preferred embodiment is that, the distance between utmost point post 20 and the connection piece 1 up end is less than the thickness of connection piece 1, therefore the laser need not pierce through the upper and lower both sides of connection piece 1 completely just can weld utmost point post 20, so not only can reduce the use power of laser welding equipment, still helps promoting the penetration simultaneously to promote the welding reliability.

In the second embodiment, preferably, two connection holes penetrating through the upper and lower sides of connection piece 1 are respectively disposed on connection piece 1, for convenience of description, the two connection holes are named as first connection hole 11 and second connection hole 12, wherein the first connection hole 11 is adapted to the shape of first pole column 201, and the second connection hole 12 is adapted to the shape of second pole column 202, so that first pole column 201 can be installed in first connection hole 11, and second pole column 202 can be installed in second connection hole 12. Because first connecting hole 11 and second connecting hole 12 have all run through the upper and lower both sides of connection piece 1, therefore lie in the welding equipment of connection piece 1 top when the welding and can direct contact utmost point post 20 and no longer need pierce through connection piece 1 earlier, consequently also be more convenient for weld. Meanwhile, the welding position can be directly observed, so that the welding effect can be conveniently determined.

To facilitate insertion of the post 20 into the connection hole, the connection hole is clearance fit with the post 20 prior to welding. However, the clearance between the connection hole and the post 20 should not be too large, which may affect the reliability after welding. In the embodiment, the pole 20 is preferably welded and fixed to the connection hole by a laser welding process. According to the experience of the prior art, the welding reliability of laser welding can be greatly reduced when the gap between two objects is greater than 0.2mm, therefore, it is preferable to set the distance between the pole 20 and the connecting hole to be less than 0.2mm before welding, specifically to this embodiment, the pole 20 is cylindrical, the connecting hole is also cylindrical, therefore, in order to realize the technical scheme that the distance between the pole 20 and the connecting hole is less than 0.2mm, the difference between the inner diameter of the connecting hole and the outer diameter of the pole 20 can be preferably set to be less than 0.4mm, in this scheme, no matter where the pole 20 is actually located in the connecting hole, the pole 20 surface is provided with the position where the distance between the pole 20 and the connecting hole is less than 0.2mm, and thus the welding reliability can be ensured. Further preferably, the distance between the pole 20 and the connecting hole can be further limited to be less than 0.15mm. The purpose of this further limitation is that when welding is performed by using a laser seam welding process with lower power, the laser seam welding process generally requires the gap between the objects to be less than 0.15mm, so the present embodiment preferably defines the distance between the pole post 20 and the connection hole to be less than 0.15mm for laser seam welding. Since the connecting sheet 1 and the terminal post 20 are both machined parts which can be automatically machined by automatic equipment, machining a structure meeting the above dimensional requirements by using the existing machining equipment is easy to realize, and therefore, the embodiment does not complicate the machining process, thereby being beneficial to controlling the cost.

In view of the fact that the connecting sheet 1 is a conductor when an overcurrent needs to be carried, and the outer surface of the battery cell body 25 is generally made of a metal material and is also a conductor, in order to prevent a current loop from being formed between the connecting sheet 1 and the battery cell body 25, an insulating sheet 21 is sandwiched between the battery cell body 25 and the connecting sheet 1, and the insulating sheet 21 is made of an insulating material and has a function of separating the battery cell body 25 from the connecting sheet 1, so that the battery cell body 25 and the connecting sheet 1 are prevented from forming a current loop. Specifically, a structure of a preferred embodiment of the insulation sheet 21 can be seen with reference to fig. 5, the insulation sheet 21 includes an insulation sheet body 210 made of an insulation material and insulation sheet mounting holes 211 provided on the insulation sheet body 210, the pole post 20 passes through the insulation sheet mounting hole 211, and the pole post 20 protrudes upward with respect to the insulation sheet body 210. On the premise of satisfying the insulation requirement, the insulation sheet body 210 may be designed to be thinner as much as possible so that the terminal 20 can be normally inserted into the connection hole. For convenience of assembly, the lower surface of the insulation sheet body 210 is matched with the outer surface of the battery cell body 25, so that the two can be attached to each other; similarly, the upper surface of the insulation sheet body 210 is matched with the lower surface of the connection sheet 1, so that the two can be attached to each other. This arrangement contributes to enhancing the connection reliability of the connection piece 1, and prevents the insulating sheet body 210 from being pried when the connection piece 1 presses the insulating sheet body 210.

For the convenience of understanding, the structure of the battery cell provided by the present embodiment may refer to fig. 3 and 4, wherein the cell body 25 includes the cell casing 250, the pins 24, and the substrate assembly 22. The pins 24 are connected to unshown components disposed in the cell casing 250, which belongs to the prior art and is not described in detail herein. The pin 24 is provided with a pin mounting hole 241, and the pole 20 is inserted into the pin mounting hole 241. The substrate assembly 22 is fixedly connected to the cell casing 250, and the substrate assembly 22 and the cell casing 250 together enclose a closed casing. The substrate assembly 22 is provided with a substrate mounting hole 221, and the pole 20 penetrates through the substrate mounting hole 221, so that the pole 20 protrudes upward relative to the cell body 25. In order to prevent the battery cell casing 250 from leaking, the electrode post 20 is further sleeved with a seal ring 23, and the seal ring 23 is interposed between the substrate assembly 22 and the pin 24 to seal the substrate mounting hole 221 and the pin mounting hole 241. The insulating sheet 21 is fixedly connected to the substrate assembly 22. Compared with the prior art shown in fig. 7 and 8, in the preferred embodiment, the terminal 20 is particularly limited to protrude upwards relative to the cell body 25, and the connecting sheet 1 is sleeved outside the terminal 20, so that the connecting sheet 1 plays a role of the pressing plate 26, and therefore, the pressing plate 26 is not required to be arranged, and the overall structure of the battery cell is simplified. In addition, under the condition that the pressing plate 26 is not arranged, the whole battery monomer is reduced by a certain height, and the energy density of the battery monomer is improved.

In the above-mentioned solution, for the battery cell, the structures and functions of various components in the battery cell body 25, the specific structure and functions of the terminal post 20, and other structures that are described but not described in detail are all related to the prior art, and are not described again here. Meanwhile, in the case where more than two battery cells are connected at the same time to constitute a battery pack, it is also only necessary to adaptively modify the structure with reference to the above-described embodiment. It should be noted that the features of the embodiments in the present application may be combined with each other without conflict.

The present embodiment also provides a battery pack connection method for producing the battery pack provided in the above embodiment. This embodiment is exemplified by a battery pack composed of two battery cells.

Before connection, the connecting sheet 1 and the single battery provided in the above embodiment are prepared respectively, a connecting hole with a size meeting requirements can be machined on the connecting sheet 1, and meanwhile, the pole 20 of the single battery can also be machined to a size meeting requirements. After the preparation is finished, the following steps are carried out:

s1: two battery cells are arranged side by side. The battery cell is the battery cell provided in the above embodiment, wherein the pole 20 protrudes upward relative to the cell body 25. The purpose of the side-by-side arrangement here is to align the first pole 201 and the second pole 202 for subsequent contact with the tab 1.

S2: connecting sheet 1 between two single batteries, when installing, first connecting hole 11 is correspondingly sleeved on first pole 201, and second connecting hole 12 is correspondingly sleeved on second pole 202. The connecting hole is in clearance fit with the pole 20, so that the pole 20 is prevented from being damaged due to extrusion of the inner wall of the connecting hole during sleeving. Simultaneously, the height of preferred utmost point post 20 and the length of connecting hole satisfy, and utmost point post 20 is after wearing to locate the connecting hole, and the up end parallel and level of utmost point post 20 is in or slightly less than the up end of connection piece 1 to it is easy damaged to avoid utmost point post 20 to extend the connecting hole and lead to utmost point post 20.

S3: and (3) welding and fixing the pole 20 and the connecting hole by using welding equipment. The welding device preferably uses a laser welding device, the power of which can be reduced accordingly, since in this embodiment the laser welding device no longer requires the possibility of penetrating the connecting piece 1. In practice, the laser welding equipment can meet the requirement when working under the 1500W working condition, and the laser welding equipment can meet the requirement under the 3800W working condition generally required by the prior art, so that the energy consumption is obviously reduced by the optimal selection scheme, and the cost is saved.

In a further preferred embodiment, the laser welding preferably uses a laser seam welding process. Laser seam welding is an existing laser welding scheme, and simply speaking, laser is directly controlled to move along a track of a gap, and the laser melts solids on two sides of the gap to realize welding. Laser welding this process requires that the laser must be able to directly contact the two objects to be welded. In the embodiment, the through hole is connected with the hole, so that the requirement of laser seam welding is met. During welding, the outer contour of the pole 20 is used as a welding seam track, and the moving track of laser is convenient to set, so that the process is simplified. Moreover, the outer contour of the pole 20 is used as a welding seam track, so that the welding effect between the pole 20 and the inner wall of the connecting hole is optimal, and the connecting sheet 1 and the pole 20 are ensured to have good overcurrent capacity.

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, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. A battery pack comprising two battery cells, the battery cells comprising:

a cell body;

the pole column is connected with the battery cell body;

the battery is characterized in that the pole is outwards protruded relative to the outer surface of the battery cell body around the pole;

the battery pack further includes:

the connecting sheet is used for connecting the two battery monomers;

the battery cells and the connecting sheet are configured in a way that one of the poles of one of the battery cells and one of the poles of the other battery cell are respectively and fixedly embedded in the same connecting sheet.

2. The battery pack according to claim 1, wherein the connecting sheet is provided with at least two connecting holes penetrating upper and lower sides of the connecting sheet, and the post is fixedly connected to the connecting holes.

3. The battery pack according to claim 1, wherein the tab has at least two grooves formed on one surface thereof, and the terminal is fixedly coupled to the grooves.

4. The battery pack according to claim 2, wherein the pole is welded and fixed to the connection hole.

5. The battery pack of claim 1, wherein the battery cells further comprise an insulating sheet sandwiched between the connecting sheet and the cell body.

6. The battery of claim 5, wherein the insulating sheet comprises:

the upper surface of the insulating sheet body is attached to the lower surface of the connecting sheet, and the lower surface of the insulating sheet body is attached to the surface of the battery cell body;

the insulating piece mounting hole is located on the insulating piece body, utmost point post wears to locate the insulating piece mounting hole.

7. The battery according to any one of claims 1 to 6, wherein the connecting tab is made of an aluminum alloy.

8. The battery according to any one of claims 1 to 6, wherein the upper end of the pole is lower than or flush with the upper end surface of the connecting tab.

9. The battery pack of any of claims 1-6, wherein the cell body comprises:

a cell shell;

the pin is fixedly arranged in the battery cell shell;

the substrate assembly is fixedly connected with the battery cell shell so as to enable the battery cell body to form a closed structure;

the pole column sequentially penetrates through the pin and the substrate assembly and extends out of the substrate assembly.

10. The battery of claim 9, wherein the post is sleeved with a sealing ring, the sealing ring being clamped between the substrate assembly and the pin.

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