WO2015124264A1

WO2015124264A1 - Energy accumulator consisting of energy storage cells

Info

Publication number: WO2015124264A1
Application number: PCT/EP2015/000234
Authority: WO
Inventors: Marcel Kramer; Thomas Echelmeyer; Lars Ebert
Original assignee: Thyssenkrupp System Engineering Gmbh; Thyssenkrupp Ag
Priority date: 2014-02-19
Filing date: 2015-02-05
Publication date: 2015-08-27
Also published as: DE102014102094A1

Abstract

The present invention relates to an energy accumulator, said energy accumulator comprising energy storage cells each of which has at least one contact element. At least two contact elements are connected to each other via a connection element, the contact elements connected to each other being arranged individually or jointly inside a recess of the connection element, and at least one of the contact elements being integrally bonded to the connection element, preferably by a weld seam produced by laser welding.

Description

DESCRIPTION

title

Energy storage consisting of energy storage cells

State of the art

The present invention relates to an energy storage consisting of energy storage cells and a method for producing an energy storage device consisting of energy storage cells.

In the production of such energy storage, especially batteries, several

Energy storage cells arranged in a defined geometry and connected to each other via contact elements of the individual energy storage cells. Typically, the

Energy storage cells arranged side by side in a plane and the contact elements connected to each other by means of a connecting element. The connecting elements are placed on the contact elements and then connected to them. If vertical displacements occur in the arrangement of the energy storage cells, the connecting elements can no longer be placed flat, which results in a contact surface between the contact element and the contact surface

Connection element significantly reduced. This results in a lower mechanical stability of the connection, which can lead in extreme cases to tearing off of the connecting element. Furthermore, the lower contact surface generates an increased electrical resistance.

The prior art solves this problem - as disclosed in the publication DE 10 2008 059 970 AI - for example, by an additional component is integrated into the energy storage, wherein the connecting member is supported by the additional component as a rocker. Thus, although a cell contacting can be achieved, however, the component increases the manufacturing cost of the energy storage, energy storage complexity and weight. In addition, by this proposed solution, mechanical stresses that reduce a long-term stability of the compound.

Alternatively, the connection of the energy storage cell can be realized by a screw connection, as disclosed for example in DE 10 2011 083 469 AI. You can do that

Compensate for differences in height to a certain degree by tightening the nuts. As a result, however, increased mechanical stresses are caused. In addition, a screw connection with an increased and thus undesirable manufacturing effort is connected. In addition, the hold can decrease by the firm tightening over the life of the energy storage, with a difference in height promotes this dissolution.

Disclosure of the invention

It is an object of the present invention to provide an energy store and a method for its production in such a way that a durable and mechanically stable connection can be realized even if the energy storage cell is offset from one another. In particular, it should be dispensed with expensive additional components.

The object of the present invention is achieved by an energy store, wherein the

Energy storage comprises energy storage cells, each having at least one contact element, wherein at least two contact elements, preferably of different

Energy storage cells are connected to each other via a connecting element, wherein the interconnected contact elements are arranged in each case or together within a recess of the connecting element and wherein at least one of the contact elements is integrally connected to the connecting element.

Compared with the prior art, the present invention has the advantage that the

Connecting element not on the contact elements, possibly along a

Offset direction are mutually höhenverschobenen, must rest. Instead, that can

Join the contact element at least partially or include. As a result, the tilting of the connecting element can be largely suppressed or even prevented in an advantageous manner. In addition, mechanical stresses can be reduced or even avoided, which under certain circumstances can lead to a tearing off of the connecting element. At the same time a comparatively large contact area between the connecting element and

Contact element realized. It is advantageously dispensed with additional components. In particular, can be dispensed with by the cohesive connection to additional elements such as nuts. In addition, the recess saves material, which reduces weight and material usage in a positive way.

The energy store is preferably a battery, in particular a lithium-ion battery, supercaps or the like. In particular, the connecting element is arranged such that its general course is substantially perpendicular to the offset direction, in particular horizontally. It is provided that the connecting element contacts the contact element in the region of the recess. In particular, the recess can by a Formschuuss of Connecting element and contact element suppress or prevent movement of the individual energy storage cell in a direction perpendicular to the direction of displacement direction, which advantageously increases a mechanical stability of the energy storage. Advantageous embodiments and modifications of the invention are the dependent claims, as well as the description with reference to the drawings.

In a further embodiment, it is provided that the recess is adapted in its geometric shape to a cross section of the contact element and / or at least one of the contact elements by a weld caused by laser welding with the

Connecting element is connected. As a result, for example, the recess in the

Manufacturing process in a direction parallel to the direction of displacement along the

Move the contact element. It is conceivable that the recess a precisely fitting

Forming space for the contact element forms. In particular, the connecting element can be moved along a first side surface of the contact element, wherein the first side surface in

Substantially parallel to the offset direction. This advantageously makes it possible, independently of an offset between the individual energy storage cells, to place the connection element at different locations along the first side surface of the contact element without significantly reducing the contact area between the connection element and the contact element.

Preferably, the cross section is circular whereby the connecting element is rotatably mounted on the contact element in time before a joining process.

In a further embodiment, it is provided that the recess is shaped such that at least two contact elements rest against an inner side of the recess. As the inside of the recess, the surface is understood, which forms the spatial boundary of the recess and facing the recorded contact element or the recorded contact elements. It is conceivable that the one contact element is arranged at one end of the recess and the other contact element at the other end of the recess. Due to this construction space design of the connecting element, it is possible in an advantageous manner to save material and to reduce the total weight of the energy storage. But it is also conceivable that the total number of the recess corresponds to the number of contact elements and each recess one each

Contact element receives or surrounds it. In this case, the recess are preferably adapted in its shape to fit the cross-section of the contact element. In a further embodiment it is provided that at least one of the contact elements is materially connected, preferably by a weld caused by laser welding, with the connecting element. Due to the cohesive connection, a stable and durable connection between the connecting element and the contact element is advantageously realized.

In a further embodiment, it is provided that the contact element and the

Connecting element are at least partially connected to each other along a first side surface of the contact element, wherein the first side surface substantially parallel to a

Offset direction runs. By arranging the connecting element on the first side surface is advantageously dispensed with, hang the connecting element on the contact element, which would otherwise lead to a tilting of the contact elements to each other and thus to a reduction of the contact surface. In a further embodiment, it is provided that the connecting element has recesses whose relative distance on the connecting element, the arrangement of the

Energy storage cells determines each other. In particular, the recesses may be arranged following a pattern on the connecting element, wherein the pattern dictates the positioning of the individual energy storage cells. As a result, arranging the energy storage cell during the production process can be simplified in an advantageous manner.

In a further embodiment, it is provided that the recess is designed such that it defines an orientation of the energy storage cells. For example, the recess is n-angular, whereby a correspondingly n-angular contact element n different discrete

Orientation options are given. In this case, orientation is understood in particular to be a rotation about an axis running parallel to the direction of offset. It is also conceivable that contact element and connecting element in the sense of a key-lock principle have complementary configured positive locking means, the only one orientation of the

Allow contact element in the recess. For example, the contact elements provided as the + pole are round and those provided as -Pole are square, thereby positively enforcing proper placement of the connection element and preventing false interconnection. By restricting the orientation possibilities, the placement of the energy storage cell in the manufacturing process is simplified and the mechanical stability is further increased. In a further embodiment, it is provided that at least one of the contact elements has a shoulder, wherein the connecting element rests at least partially on the shoulder. The heel simplifies the arrangement of the connecting element in the manufacturing process in an advantageous manner. In addition, the contact surface between the contact element and

Increased connecting element. It is provided that the paragraph is integrated into the first side surface of the contact element. In particular, the shoulder causes a tapering of the contact element along a direction parallel to the direction of displacement. It is conceivable that the first side surface is angled to the offset direction. In particular, the contact element has at least partially a frusto-conical shape, which simplifies the placement of the connecting element.

In a further embodiment, it is provided that the number of contact elements with a shoulder is smaller than the total number of contact elements. Then, the connecting element rests on at least one shoulder and the connecting element can be arranged independently of the offset of the individual energy storage cell at an arbitrary position along the contact element without having to tilt. Another advantage is that the connecting element can be arranged below an upper end of the contact element and thus of the energy store. As a result, the total extent of the manufactured energy storage is not increased by the connecting element and thus provided a compact energy storage available.

In a further embodiment, it is provided that the contact element

- a recess,

a rounded transition between the first side surface and a second side surface of the contact element, the second side surface extending substantially perpendicular to the direction of displacement, and / or

- a closure means

having. With the indentation, the connecting element can be prefixed before a forming process, such as laser welding, in an advantageous manner. In this case, the connecting element is preferably arranged between the shoulder and the indentation. The rounded transition between the first and second side surfaces brings the advantage that

Connecting element simply and safely, in particular without tilting to arrange on the energy storage cell or on the contact element. The closure means can be used advantageously to close a possible gap between the connecting element and the contact element. It is conceivable that the closure means is made of the same material as the connecting element and / or the contact element. But it is also conceivable alternatively that the closure means is made of a material which has special properties with regard to its electrical conductivity, its melting temperature and / or its corrosion. Furthermore, it is provided that the closure means is in one piece. For example, the closure means is a closure ring.

In a further embodiment, it is provided that the connecting element has a further shoulder, which adjoins the recess, wherein the further shoulder extends substantially parallel to the first side surface of the contact element. As a result, the contact surface between the contact element and connecting element can be increased in an advantageous manner.

In a further embodiment, it is provided that

- The connecting element is electrically conductive and / or

- The energy storage cells are connected to each other via the connecting element in a parallel or series connection. This can advantageously the

Energy storage properties of the individual energy storage cell can be used advantageously for the energy storage.

Another object of the present invention is a process for the preparation of a

Energy storage, wherein in a first process step, a connecting element having at least one recess, and energy storage cells, each having at least one contact element are provided, wherein in a second process step at least one of the contact elements is at least partially disposed within the recess.

Compared to the prior art, the connecting element can be attached to the energy storage cells thanks to the recesses such that the connecting element does not have to be arranged at least partially on the contact elements, whereby tilting of the connecting element can be advantageously suppressed.

In a further embodiment, it is provided that in a third method step, the contact element with the connecting element is materially connected, preferably by means of laser welding. As a result, a secure, durable and mechanically stable connection between the contact elements and the connecting elements can be realized. In a further embodiment, it is provided that the method of one of the above-described energy storage is produced.

Further details, features and advantages of the invention will become apparent from the drawings, as well as from the following description of preferred embodiments with reference to the drawings. The drawings illustrate only exemplary embodiments of the invention, which do not limit the essential inventive idea

Brief description of the figures

FIG. 1 shows an energy store according to the prior art

FIG. 2 shows an energy store according to a first exemplary embodiment of the present invention.

FIG. 3 shows contact areas for energy stores according to second, third, fourth and fifth exemplary embodiments of the present invention.

FIG. 4 shows an energy store according to a sixth exemplary embodiment of the present invention.

FIG. 5 shows two energy stores according to a seventh and an eighth embodiment of the present invention. Embodiments of the invention

In the various figures, the same parts are always provided with the same reference numerals and are therefore usually named or mentioned only once in each case. FIG. 1 shows an energy store 10 according to the prior art. In the illustrated form, the energy store 10 consists of four, along a connecting direction A juxtaposed energy storage cells 10, each having a contact element 2 at its upper end. It is provided that at least two contact elements 2 by means of a

Connecting element 1 with each other, in particular electrically conductive, are connected. According to the prior art, the connecting elements 1 are placed on the contact elements 2 for this purpose and then connected to each other, in particular by means of a laser 9 welded. Here, in the best case, the connecting element 2, in particular a bottom of the

Connecting element 2, as large as possible rest on the contact elements 2. Since the manufacturing process of the energy storage device 1 can not generally guarantee that the individual energy storage cells 5 are arranged at the same height relative to one another, height differences 15 occur under the individual energy storage cells 10. Such a

Height difference 15 causes the connecting element 1 slightly tilted to

Connection direction A is arranged, whereby the connecting element 1 can not rest over a large area on the contact element 2. This illustrates particularly clearly the enlarged in Figure 1 representation of a contact area 11, in which the contact element 2 with the

Connecting element 1 is in contact. Instead of lying flat on the contact element 2, a wedge-shaped gap is formed between the connection element 1 and the contact element 2.

Consequences are a reduction of the mechanical stability and an undesirable increase of the electrical resistance in the transition region between two energy storage cells 1.

FIG. 2 shows an energy store 10 according to a first exemplary embodiment of the present invention. On the left side are several side by side arranged

Energy storage cells 5 illustrated having contact elements 2 at the upper end. in the

Energy storage 10 shown are the individual energy storage cell 5 along a

Offset direction B shifted from each other. For connection, preferably for electrical

Connection, the individual energy storage cell 5 is provided that the contact elements 2 via a connecting element 1, the recesses 8, are interconnected. In this case, the recesses 8 are designed or shaped such that they in the manufacturing process

Contact element 2 at least partially, preferably completely, can accommodate. In other words, the recess is configured such that the contact element 2 can be placed within the recess 8 of the connecting element 2. In particular, the recesses 8 are designed such that the connecting element 1 along a direction parallel to the offset B

extending direction is displaced or displaced before it is connected to the contact element 2, preferably cohesively. Preferably, the recess 8 is configured such that it along at least one direction perpendicular to the direction of displacement direction

is arranged positively to the contact element 2. Furthermore, it is envisaged that the

Connecting element 1 abuts against a first side surface 3 of the contact element 2, wherein the first side surface 3 is substantially parallel to the offset direction B. In the case of the first

exemplary embodiment, the recess 8 is circular and the contact element 2 abuts the contact element 2 along the circumference of a circle. This shows the one on the right side of the Figure 2 shown illustration. Due to the circular configuration of the recess 8 can be in the manufacturing process, a free rotation of the connecting element 1 relative to the

Realize contact element 2. But it is also conceivable that the recess 8 has a different shape, such. B. that of a polygon. It thereby advantageously possible, the orientation of the respective

Energy storage cell 5 set. Furthermore, it is conceivable that the geometric shape in the sense of a key-lock principle ensures that a particular connection element 1 can be assembled only with the correspondingly provided contact elements 2.

For example, the contact elements, which are provided as a + pole, are round and those which are provided as -Pole, square, which can be prevented in a positive manner, a false interconnection.

Furthermore, it is provided that the contact element 2, in particular the first side surface 3 of the contact element 2, has a shoulder 17 on which the connecting element 8 can rest. In this case, the shoulder 17 is preferably arranged at half the height of the contact element 2. Furthermore, it is provided that a plurality of contact elements 2 are connected to each other via the connecting element 1, wherein the number of contact elements 2 with a paragraph 17 is less than the total number of interconnected contact elements 2. Then, the connecting element 1 is located on one of the paragraphs 17 and on a contact element 2 without paragraph at a height that is dependent on the offset of the respective energy storage cells 5 to each other. As a result, the connecting element 1 can be arranged independently of the extent of the offset along a plane that is as perpendicular as possible to the offset direction B. Furthermore, it is conceivable that the

Connecting element 1 and the contact element 2 at least partially along the first

Side surface 3 of the contact element 2 are materially connected. Preferably, the connecting element 1 and the contact element 2 are joined to the first side surface by means of a laser 9, in particular welded. Furthermore, it is conceivable that the connecting element 1 connects the energy storage cells 5 in pairs.

FIG. 3 shows contact regions for energy stores 10 according to a second, third, fourth and fifth exemplary embodiment of the present invention. In the upper left figure of Figure 3, the contact element 2 according to the second exemplary

Embodiment on a recess 12. In particular, the recess 12 is arranged along the first side surface 3 immediately above the shoulder 17. The indentation 12 in particular has the effect that the connecting element 1 can be pre-fixed in time before a joining process, such as welding. To limit the movement of the Connecting element 1 along the offset direction B, the indentation 1 acts positively along a direction parallel to the direction of offset B direction with the placed on the shoulder 17 connecting element 1 together. In the upper right-hand illustration of FIG. 3, the contact element 2 according to the third exemplary embodiment of the present invention has a rounded transition between the first side face 3 and a second side face 4, wherein the second side face 4 is substantially perpendicular to the offset direction B. The rounded transition facilitates the placement of the contact element 2 within the recess 8 of the connecting element 1 in a positive manner in the production process of the energy store 10. It is also conceivable that the contact element 2 tapers towards its upper end and is preferably at least partially frusto-conical in shape.

In the two lower illustrations of FIG. 3, the contact elements 2 according to the fourth and fifth embodiments of the present invention each have a closure means 6, the closure means 6 having a triangular cross section in the fourth embodiment and a circular cross section in the fifth embodiment. The closure means 6 is preferably arranged above the connecting element 1. In this case, the connecting element 1 is arranged in particular between the heel and the closure means 6. Such

Closure means 6 is capable of a possible gap between contact element 2 and

Compound element 1 to close and in a positive way the contact surface between

Further increase connecting element 1 and contact element 2. It is conceivable that the closure means 6 and the connecting element 1 are made of the same material.

Preferably, the closure means 1 is integrally formed. For example, that is

Locking means 6 a locking ring. But it is also conceivable that the closure means 6 made of the material of the contact element 2 or comprises a material which has over the Verbingungselement 1 and the contact element 2 advantageous properties, such as a low melting point, high conductivity, high

Corrosion resistance or the like. Preferably, the connecting element melts at least partially, runs in a gap between the connecting element and the contact element and closes this gap.

FIG. 4 shows an energy store 10 according to a sixth exemplary embodiment of the present invention. It is provided here that the projection 8 is shaped in such a way, preferably shaped as a slot, is that the contact elements 2 of different Energy storage cells 2 can be arranged within the recess. It is provided that the recess 8 is formed such that at least two contact elements 2 abut an inner side 18 of the recess 8. The inside 18 is understood to be the surface which forms the spatial boundary of the recess 8 and faces the received contact element. It is conceivable that the one contact element 2 is arranged at one end of the recess 8 and the other contact element 2 at the other end of the recess 8. This design space configuration of the connecting element 1, it is advantageously possible to save material and consequently the Total weight of the energy storage 10 to reduce

5 shows energy stores 10 according to a seventh and eighth exemplary embodiment of the present invention, the connecting element 1 not yet being arranged on the energy storage cells 5 in the upper illustration of FIG. 5 and the connecting element 1 on the energy storage cells 5 in the lower illustrations is arranged

is preferably connected via a weld with the contact elements 2. Preferably, the connecting element 1 of the seventh embodiment has a further shoulder 19, which at least partially surrounds one of the contact elements 2 substantially parallel to the first one

Side surface 3 of the contact element extends. In this case, determines the height of the other paragraph 19 at what level of the contact elements 2, the connecting element 1 extends and thereby also ensures its horizontal alignment. This allows the contact surface between

Make connecting element 1 and contact element 2 as large as possible. In the eighth

Embodiment, at least two other paragraphs are provided, the other paragraphs 19 are each deformable. In particular, the further paragraphs 19 are deformable such that they provide for the positioning of the connecting element 1 on the energy storage cells 5 for a horizontal alignment of the connecting element 1. Due to the plurality of further paragraphs 19, the contact surface between the connecting element 1 and the contact elements 2 can be further increased in an advantageous manner.

LIST OF REFERENCE NUMBERS

1 connecting element

2 contact element

3 first side surface of the contact element

4 second side surface of the contact element

5 energy storage cell

6 closure means

8 recess

9 lasers

10 energy storage

11 contact area

12 indentation

15 height difference

17 paragraph

18 inside

19 more paragraph

A connection level

B offset direction

Claims

claims

An energy store (10), wherein the energy store (10) comprises energy storage cells (5) each having at least one contact element (2), wherein at least two

Contact elements (2) via a connecting element (1) are interconnected, wherein the interconnected contact elements (2) each or together within a recess (8) of the connecting element (1) are arranged and wherein at least one of the contact elements (2) cohesively with the Connecting element (1) is connected.

2. energy store (10) according to one of the preceding claims, wherein the recess (8) is adapted in its geometric shape to a cross section of the contact element (2) and / or at least one of the contact elements (2) caused by a laser welded weld with the Connecting element (1) is connected ,.

3. energy store (10) according to one of the preceding claims, wherein the recess (8) is shaped such that at least two contact elements (2) bear against an inner side of the recess (8).

4. Energy store (10) according to one of the preceding claims, wherein the

Contact element (2) and the connecting element (1) at least partially along a first side surface (3) of the contact element (2) are interconnected, wherein the first side surface (3) is substantially parallel to an offset direction (B).

5. Energy store (10) according to one of the preceding claims, wherein the

Connecting element (1) has recesses (8) whose relative distance on the

Connecting element (1) determines the arrangement of the energy storage cells (5) with each other.

6. energy storage device (10) according to one of the preceding claims, wherein the recess (8) in such a way, preferably as a polygon and / or in the sense of a key-lock-principle, configured that it defines an orientation of the energy storage cells (5).

7. Energy store (10) according to one of the preceding claims, wherein at least one of the contact elements (2) has a shoulder (17), wherein the connecting element (1) rests at least partially on the shoulder (17).

8. energy store (10) according to one of the preceding claims, wherein the number of contact elements (2) with paragraph (17) is smaller than the total number of contact elements (2).

9. Energy store (10) according to one of the preceding claims, wherein the

Connecting element (1) has a further shoulder (19) which adjoins the recess (8), wherein a side surface of the further shoulder (19) extends substantially parallel to the first side surface (3) of the contact element (2).

10. Energy store (10) according to one of the preceding claims, wherein the

contact element

a recess (12),

a rounded transition between the first side surface (3) and a second side surface (4) of the contact element (2), which runs substantially perpendicular to the direction of displacement (B), and / or

a closure means (6)

having.

11. Energy store (10) according to one of the preceding claims, wherein

- The connecting element (1) is electrically conductive and / or

- The energy storage cells (5) via the connecting element (1) are connected together in a parallel or series connection.

12. Energy store (10) according to one of the preceding claims, wherein the

Connecting element (1) connects the energy storage cells (5) in pairs.

13. A method for producing an energy store (10), wherein in a first

Process step, a connecting element (1) having at least one recess (8), and energy storage cells (5), each having at least one contact element (2) are provided, wherein in a second process step at least one of the contact elements (2) at least partially within the recess is arranged.

14. The method according to 13, wherein in a third method step, the contact element (2) with the connecting element (1) cohesively, preferably by means of laser welding, is connected.

5. A method for producing an energy store according to one of claims 1 to 12.