DE102011002203A1 - Battery pack for use in e.g. electric bicycle, has wiring structure arranged on upper side of electrically conductive arrester, and provided with electric conductors embedded into matrix, which is made from electrical insulating material - Google Patents

Abstract

The pack (1) has battery cells (6) switched in parallel or series manner, where poles of the battery cells are oriented to sides of the pack. The battery cells are designed as cylindrical cells, prismatic cells, lithium-ion cells and nickel-metal hydride cells. A wiring structure is arranged on an upper side of an electrically conductive arrester e.g. perforated plate, and provided with a matrix made of electrical insulating material i.e. plastic material. The wiring structure includes electric conductors embedded into the matrix, and is designed as a circuit board (100) and a flexible film. An independent claim is also included for a method for manufacturing a battery pack.

Description

The invention relates to a battery pack and a method for producing a battery pack.

Battery packs are used in a variety of mobile devices such. As mobile phones, portable computers and vehicles used. Battery packs contain a variety of battery cells, which are mechanically fixed together. The battery cells are connected in series and / or in parallel so that together they provide enough power for the operation of the portable device. Special requirements are made for battery packs for vehicles. They must be mechanically very stable, so that they do not break apart on gravel roads or cobblestones. In addition, in accidents in which, for example, another vehicle with a strong mechanical impulse acts on the battery pack, the battery cells must not burn or explode. Similar requirements for battery packs also apply to those that are operated in devices that are exposed to high mechanical loads. These can be, for example, power tools or wind turbines.

Battery packs represent highly safety-relevant components of such mobile devices. It should therefore be ensured, for example, that an escape of gas from the battery cells in case of failure is possible. In addition, a reverse polarity in the wiring of the individual battery cells should be excluded as possible. However, this is not always guaranteed in the often complicated structure of battery packs, which should also be as compact as possible.

The invention has for its object to provide a battery pack available that ensures a high level of reliability.

Another object of the invention is to provide a manufacturing method for such a battery pack that is as economical as possible.

This object is solved by the subject matter of the independent claims. Advantageous embodiments emerge from the respective subclaims.

According to one aspect, a battery pack comprises a plurality of battery cells connected in parallel or in series, wherein poles of the battery cells are oriented to a first side and / or to a second side of the battery pack.

Furthermore, the battery pack comprises a plurality of electrically conductive arresters having an upper side and a lower side, which are arranged on a first side and / or a second side of the battery pack. In this case, the battery cells can be arranged within the battery pack in particular such that the first and the second side of the battery pack opposite each other. The arresters each contact poles of a group of battery cells with their underside electrically, the arresters each having a contact pad on its upper side.

Furthermore, the battery pack comprises at least one arranged on the top of the arrester wiring structure with a matrix of an electrically insulating material and a plurality of jointly embedded in the matrix electrical conductors, wherein in each case an electrical conductor electrically contacts the pad of a conductor.

In such a battery pack, the individual groups of battery cells are conventionally wired individually. By using a prefabricated wiring structure can save considerable time in the production of the battery pack. In addition, the battery pack can be made very compact.

The wiring structure is a prefabricated component. The course of the electrical conductors within the matrix is determined and matched to the position of the contact pads of the arresters within the battery pack. In particular, the arrangement of the electrical conductors in the matrix corresponds to the arrangement of the contact pads of the arresters, that is, the electrical conductors are guided within the matrix such that they lead to the contact pads. Typically, the electrical conductors are completely embedded in the insulating matrix and are exposed only in an area on one side of the wiring structure that comes to rest on the corresponding contact pad. The risk of polarity reversal is thus considerably reduced.

The structure of the battery pack of battery cells, a plurality of arranged directly on the poles Ableitern, each of a plurality of battery cells in a group, and a directly arranged on the arresters wiring structure has several advantages. By suitable combination of the battery cells into groups by means of the arresters, the appropriate voltage can be tapped and made available in each case.

The grouping also makes it possible to keep the number of contact points in the contacting through the wiring structure low. On the one hand, this simplifies the manufacture and assembly of the wiring structure and, on the other hand, leads to greater reliability of the battery pack, because a smaller number of Contact points means a lower number of possibly faulty connections.

The electrical contacting of the battery cells is thus carried out in two layers, wherein the electrical conductors form the first layer and the prefabricated wiring structure arranged directly thereon forms the second layer. The electrical contact is thus relatively simple and requires apart from the also relatively simple structure wiring no complicated parts to be manufactured. It can therefore be flexibly adapted to the size and geometry of battery packs and is also easy to handle during installation and maintenance. This is particularly advantageous in battery packs that are manufactured in relatively small numbers and have various uses.

In one embodiment, the wiring structure is formed as a printed circuit board. Alternatively, the wiring structure may also be formed as a flexible film.

When the wiring structure is formed as a flexible film, a first portion of the flexible film may be disposed on the first side of the battery pack and a second portion of the flexible film may be disposed on the second side of the battery pack. In this embodiment, the foil is bent around at least one, typically around two edges of the battery pack.

In another embodiment, a first wiring structure is disposed on a first side of the battery pack and a second wiring structure is disposed on a second side of the battery pack. In this embodiment, not only flexible films but also rigid circuit boards can be used as the wiring structure.

Battery packs are often designed so that on two sides, usually on two opposite sides, poles of the battery cells are exposed. According to one embodiment, the construction of electrically conductive arresters and prefabricated wiring structure arranged thereon is used on both sides.

The matrix of the wiring structure may in particular be formed from a plastic material.

In one embodiment, a further wiring structure for connecting the battery pack to a control electronics is arranged at least on a third side of the battery pack.

In this case, the further wiring structure may also comprise a matrix of an electrically insulating material and a plurality of electrical conductors embedded in the matrix in common.

The further wiring structure may also be formed integrally with the wiring structure, for example when a structure having poles arranged on two opposite sides and a flexible wiring structure bent around two edges of the battery pack is used. The further wiring structure is then formed as a region of the wiring structure.

In one embodiment, the arresters are formed as plates, in particular as perforated plates. While the use of electrically conductive plates as arresters allows a particularly compact and easy-to-manufacture battery pack, holes in the plates have the additional advantage that they can on the one hand save weight, but on the other hand can provide for a special stability of the battery pack by the passage of a Kunststoffvergussmasse allow for the battery pack.

The battery pack is particularly suitable if the battery cells are designed as lithium-ion cells or as nickel-metal hydride cells. Alternatively, the battery pack can also be used for other types of battery cells, for example for double-layer capacitors, also called supercaps or EDLC, which have a suitable shape. The shape of the battery cells can be not only cylindrical but also prismatic.

The battery pack is particularly suitable for use in an electric vehicle, such as a two- or three-wheeled electric drive.

According to another aspect of the invention, there is provided a method of manufacturing a battery pack comprising assembling a plurality of battery cells into a composite such that poles of the battery cells are accessible on a first side of the composite and / or on a second side of the composite. Furthermore, a plurality of electrically conductive arresters having an upper side and a lower side are provided and poles of a respective group of battery cells are electrically contacted by the underside of a conductor. A wiring structure is placed on the upper side of the arresters, and in each case one arrester is electrically contacted by an electrical conductor of the wiring structure which is jointly embedded in an electrically insulating matrix with further electrical conductors.

With this method, a particularly secure and at the same time economic production of a battery pack is possible. Because the Wiring structure as a whole can be placed on the arrester, the wiring is performed in a single step.

The arresters can each be welded or soldered to the pole. The electrical conductors of the wiring structure can also be welded or soldered to contact pads of the arresters.

The invention is illustrated in more detail in the drawings with reference to an embodiment.

1 shows schematically an exploded view of a battery pack according to an embodiment of the invention;

2 schematically shows an electrically conductive arrester for the battery pack according to 1 ;

3 schematically shows a plan view of the plane of the arrester of the battery pack according to 1 ;

4 schematically shows a cross section through battery cells with arresters and wiring structure of the battery pack according to 1 according to a first embodiment;

5 schematically shows a plan view of a plane of the battery pack according to 4 ;

6 schematically shows a cross section through battery cells with arresters and wiring structure of the battery pack according to 1 according to a second embodiment and

7 schematically shows a plan view of a plane of the battery pack according to 6 ,

1 shows an embodiment of a battery pack according to the invention in an exploded view. The battery pack has a base plate 2 made of aluminum, on which a first tub 3 is placed with an opening facing up. In this tub 3 there is a mat 4 to which the topsides 61 of cylindrically shaped battery cells 6 be put. The battery cells 6 are drawn upside down. The tops 61 the battery cells 6 are in the 1 plotted below while the bottoms 63 are drawn above. On the tops 61 are each provided the positive poles, while at the bottom 63 in each case the negative poles are provided. The sides of the cylinder-shaped battery cells 6 be as long sides 62 designated.

In the 1 are two mounts 5 and 7 each below and above the batteries 6 shown. In the assembled state, the battery cells 6 so in these brackets 5 and 7 plugged in that the brackets 5 and 7 at the height of the long sides 62 are attached. The battery cells 6 be when assembling the battery pack 1 from these mounts 5 and 7 held and preferably remain even after assembly in the battery pack 1 ,

Above the bottom 63 the cells 6 is a second mat 8th provided by the second tub 9 is embedded with the opening facing down. In 1 not shown are so-called arresters 17 , The arresters 17 be below the top 61 the battery cells 6 provided to connect the positive poles together. These arresters 17 are designed in one embodiment as copper plates. These plates are perforated and welded to the positive poles. Further arresters 17 be on the negative poles at the bottom 63 the battery cells 6 provided, they are each welded to the negative poles.

The arresters 17 are, as in the following by the 2 to 7 shown electrically with the boards 100 and 110 connected. On the boards 100 and 110 voltage converters and control chips are provided. These voltage transformers and control chips are with a plug 13 connected to an opening 130 of the battery pack 1 is appropriate. Thus, the voltage transformers and the control on the boards can 100 and 110 from outside the battery pack 1 be contacted.

It is also a holder consisting of sleeves 14 , Longitudinal struts 12 , Cross struts 11 and screws 15 intended. The sleeves run parallel to the battery cells 6 , being in indentations 30 the tubs 3 and 9 are fitted. The screws 15 , of which for the sake of clarity only one is drawn, are by the cross struts 11 , the longitudinal struts 12 , the sleeves 14 to nuts 16 led, with which they are screwed. The nuts 16 are with the base plate 2 firmly connected. With the help of the holder, the tubs 3 and 9 pressed against each other, giving extra stability for the battery pack 1 means.

A cover 10 is provided with the plate 2 is screwed, leaving the plate 2 with the cover 10 and a side cover 120 forms a housing in the interior of which all other previously mentioned components are located.

In the presentation of 1 are a first potting compound, with each of the tub 3 , the mat 4 as well as the battery cells 6 are interconnected, as well as a second potting compound, the battery cells 6 , the mat 8th and the tub 9 connects, not drawn.

2 shows a trap 17 in a top view. The arrester 17 is shaped as a plate containing several circular holes 170 and several H-shaped holes 171 having. The circular holes 170 are preferably perpendicular above holes in the mat 4 intended. This allows the potting compound 18 in the holes so that vertical columns are formed, which pass through the holes continuously.

The H-shaped holes 171 are provided where the arrester 17 is welded to the battery cells. In 2 not shown are pads of the arrester 17 ,

In total, 16 arresters 17 for the battery pack 1 intended. The arresters 17 for the bottom 63 the battery cells 6 are like the arresters 17 for the top 61 built up. For a parallel connection of the battery cells 6 become the arresters 17 all with positive poles or negative poles of the battery cells 6 connected. For a series connection, some of the arresters 17 with plus poles and other arresters 17 connected with negative poles.

3 shows a plan view of the plane of the bottom 63 the battery cells 6 arranged arrester 17 of the battery pack 1 , In this illustration, for the sake of clarity, the circular holes 170 not shown in the embodiments of the battery pack 1 can also be dispensed with.

In 3 it can be seen that the battery cells 6 to groups 20 with four or eight battery cells 6 are summarized, whose poles each by an arrester 17 are electrically connected. It will each be the side of a trap 17 that the battery cells 6 facing, referred to as the bottom.

The side facing the wiring structure is called the top side 173 designated. Analog is the arrester 17 facing side of the wiring structure as the underside and the opposite side as the top, without affecting the final orientation within the battery pack 1 Consideration is taken.

At the in 3 at the top drawn arrester 17 are to illustrate the arrangement dashed contours of the undersides 63 the below the arrester 17 arranged battery cells 6 located. The arresters 17 contact with their bases the bases 63 the battery cells 6 ,

Each of the arresters 17 has a contact patch 172 on its top 173 on. The contact spots 172 are for contacting the arrester 17 provided by the wiring structure, in 3 not shown. In the area of contact spots 172 becomes the wiring structure with the arresters 17 connected, as described below. The wiring structure is for connecting the battery cells 6 with the boards 100 . 110 intended.

4 schematically shows a cross section through battery cells 6 a group 20 a battery pack 1 according to a first embodiment.

The battery cells 6 show on their undersides 63 , which in the illustration according to 4 are oriented upwards, poles on, passing through an arrester 17 electrically connected to each other. For this purpose, the arrester contacts 17 with its bottom 174 the bottom 63 the battery cells 6 , On his top 173 indicates the arrester 17 a contact patch 172 in the illustrated first embodiment through an area of the top 173 of the arrester 17 is formed, incidentally, from the top 173 does not lift off.

On the top 173 of the arrester 17 is a wiring structure 18 arranged, which is an electrically insulating matrix 180 and embedded electrical conductors therein 181 one of which is in 4 is shown. While the top 183 the wiring structure 18 in this embodiment completely through the material of the matrix 180 is formed, lies at the bottom 184 the wiring structure 18 the electrical conductor 181 at a contact point 182 free. The contact point 182 is just above the contact patch 172 of the arrester 17 arranged so that at the contact point 182 an electrical connection between the arrester 17 and the wiring structure 18 comes about.

5 schematically shows a plan view of the plane of the wiring structure 18 of the battery pack 1 according to 4 , In the 3 in the plan view shown arrester 17 are here, as they are below the wiring structure 18 are arranged, dashed lines.

The wiring structure 18 is with her bottom 184 on the top 173 the arrester 17 arranged. In 5 is the top view on the top 183 the wiring structure 18 shown. It can be seen that the wiring structure 18 a number of in the matrix 180 embedded electrical conductors 181 that at contact points 182 at least at the bottom 184 the wiring structure exposed and the contact marks 172 the arrester 17 contact electrically. The wiring structure 18 In this embodiment, it covers substantially the entire plane of the battery pack 1 with all arresters 17 on the bottom 63 the battery cells are arranged.

For wiring the battery pack 1 According to the first embodiment, for example, proceed as follows: On the battery cells inserted into the housing 6 become the arresters 17 with their bottoms 174 applied and welded to the poles of the battery cells. This will cause the battery cells 6 to groups 20 summarized. Subsequently, the wiring structure 18 put on and aligned so that their contact points 182 where the electrical conductors 181 on the bottom 184 lie free, each on a contact patch 172 an arrester 17 to come to rest. Now the electrical conductors 181 at the contact points 182 with the arresters 17 welded or soldered.

So that the contact points 182 For this purpose, the electrical conductor can be better accessible 181 at contact points 182 also at the top 183 the wiring structure 18 exposed. At the in 4 shown embodiment, in contrast, at the top 183 the electrical conductor 181 is covered by matrix material, depending on the matrix material and the soldering or welding temperature used, the matrix material can be locally melted or removed.

On the other side of the battery pack 1 can the tops 61 the battery cells 6 either wired in the same way or the order of the individual process steps is changed. For example, it is conceivable on the other side of the battery pack 1 make the wiring before the battery cells 6 be inserted into the housing.

Because the wiring structure 18 provided as a prefabricated component and as a whole on the already mounted arresters 17 is a time-consuming wiring of all individual arresters 17 not necessary anymore. Due to the prefabricated structure of the wiring structure 18 In addition, the contact is specified and a dangerous polarity reversal can be excluded.

The 6 and 7 show schematically details of a battery pack 1 according to a second embodiment. This second embodiment differs from that in the 4 and 5 shown first by the preparation of the electrical connection between the wiring structure 18 and the arresters 17 ,

According to the second embodiment, it is provided that the contact pads 172 through a partially punched-out area of the arresters 17 are formed in the assembly of the wiring structure 18 first of the battery cells 6 is bent upwards. The matrix 180 the wiring structure 18 is formed less large area than in the first embodiment. It does not cover the entire level of the battery pack 1 but is sufficient for every electrical conductor 181 only up to the contact point 182 , At the contact point 182 is the electrical conductor 181 free. He can therefore under the upwardly bent contact marks 172 be pushed, which is then bent down so that it is the electrical conductor 181 pinches or at least touches. Subsequently, a permanent connection can be made by soldering or welding.

LIST OF REFERENCE NUMBERS

1

battery pack

2

baseplate

3

first tub

4

first mat

5

bracket

6

battery cell

7

bracket

8th

second mat

9

second tub

10

cover

11

crossbars

12

longitudinal struts

13

plug

14

sleeves

15

screw

16

nuts

17

arrester

18

wiring structure

20

group

30

Dent of the tub

61

top

62

long side

63

bottom

100

circuit board

110

circuit board

120

Side wall or side cover

130

opening

170

hole

171

hole

172

contact patch

173

top

174

bottom

180

matrix

181

electrical conductor

182

contact point

183

top

184

bottom

Claims (17)

Battery pack ( 1 ), comprising: - a plurality of battery cells connected in parallel or in series ( 6 ), where poles of the battery cells ( 6 ) to a first side and / or to a second side of the battery pack ( 1 ) are oriented; A plurality of electrically conductive arresters ( 17 ) with a top side ( 173 ) and a bottom ( 174 ) on a first side and / or a second side of the battery pack ( 1 ) are arranged and each pole of a group ( 20 ) of battery cells ( 6 ) with its underside ( 174 ), the arresters ( 17 ) on its upper side ( 174 ) each have a contact patch ( 172 ) exhibit; - at least one on the top ( 174 ) of arresters ( 17 ) arranged wiring structure ( 18 ) with a matrix ( 180 ) of an electrically insulating material and a plurality of together in the matrix ( 180 ) embedded electrical conductors ( 181 ), wherein in each case an electrical conductor ( 181 ) the contact patch ( 172 ) of an arrester ( 17 ) contacted electrically. Battery pack ( 1 ) according to claim 1, wherein the wiring structure ( 18 ) is designed as a printed circuit board. Battery pack ( 1 ) according to claim 1, wherein the wiring structure ( 18 ) is designed as a flexible film. Battery pack ( 1 ) according to claim 3, wherein a first region of the flexible film on the first side of the battery pack ( 1 ) and a second portion of the flexible film on the second side of the battery pack ( 1 ) are arranged. Battery pack ( 1 ) according to one of claims 1 to 3, wherein a first wiring structure ( 18 ) on a first side of the battery pack ( 1 ) and a second wiring structure on a second side of the battery pack ( 1 ) is arranged. Battery pack ( 1 ) according to one of claims 1 to 5, wherein the matrix ( 180 ) is formed of a plastic material. Battery pack ( 1 ) according to one of claims 1 to 6, wherein the arrangement of the electrical conductors ( 181 ) in the matrix ( 180 ) the arrangement of the contact spots ( 172 ) of arresters ( 17 ) corresponds. Battery pack ( 1 ) according to one of claims 4 to 7, wherein at least on a third side of the battery pack ( 1 ) another wiring structure for connecting the battery pack ( 1 ) is arranged with a control electronics. Battery pack ( 1 ) according to claim 8, wherein also the further wiring structure is a matrix ( 180 ) of an electrically insulating material and a plurality of together in the matrix ( 180 ) embedded electrical conductors ( 181 ) having. Battery pack ( 1 ) according to one of claims 1 to 9, wherein the arresters ( 17 ) are formed as perforated plates. Battery pack ( 1 ) according to one of claims 1 to 10, wherein the battery cells ( 6 ) are formed as cylindrical cells. Battery pack ( 1 ) according to one of claims 1 to 10, wherein the battery cells ( 6 ) are formed as prismatic cells. Battery pack ( 1 ) according to one of claims 1 to 12, wherein the battery cells ( 6 ) are formed as lithium-ion cells or as nickel-metal hydride cells. Electric vehicle with a battery pack ( 1 ) according to one of claims 1 to 13. Method for producing a battery pack ( 1 ), comprising: arranging a plurality of battery cells ( 6 ) in such a way that, on a first side of the composite and / or on a second side of the composite, poles of the battery cells ( 6 ) are accessible; Providing a plurality of electrically conductive arresters ( 17 ) with a top side ( 173 ) and a bottom ( 174 ) and electrically contacting each of a group of poles ( 20 ) of battery cells ( 6 ) through the bottom ( 174 ) of an arrester ( 17 ); - placing a wiring structure ( 18 ) on the top ( 173 ) of arresters ( 17 ) and electrically contacting a respective arrester ( 17 ) by one with further electrical conductors ( 181 ) together in an electrically insulating matrix ( 180 ) embedded electrical conductors ( 181 ) of the wiring structure ( 18 ). The method of claim 15, wherein the arresters ( 17 ) are each welded to the pole or soldered. Method according to claim 15 or 16, wherein the electrical conductors ( 181 ) of the wiring structure ( 18 ) on contact spots ( 172 ) of arresters ( 17 ) welded or soldered.

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