DE102015007137A1 - Process for the preparation of a single cell, single cell and electrochemical energy storage - Google Patents

Abstract

The invention relates to a method for producing a single cell (1) for an electrochemical energy store, wherein the single cell (1) comprises a cell housing (2) comprising two housing parts (2.1, 2.2). According to the invention, an edge region (2.1.1) of at least one first housing part (2.1) is at least partially cold-formed after a juxtaposition of the housing parts (2.1, 2.2) such that a positive and / or non-positive connection between the two housing parts (2.1, 2.2) will be produced. Furthermore, the invention relates to an individual cell (1) produced by means of the method and to an electrochemical energy store having a number of such individual cells (1) electrically connected in series and / or in parallel.

Description

The invention relates to a method for producing a single cell for an electrochemical energy store, wherein the single cell comprises a cell housing of two housing parts. Furthermore, the invention relates to a single cell produced by means of such a method and an electrochemical energy store.

From the US 2006/0141356 A1 a battery cell with a cell housing is known, which is formed from a first housing part and a second housing part. By forming an edge region of the first housing part, this is mechanically connected to an edge region of the second housing part. In this case, the edge region of the first housing part surrounds the edge region of the second housing part. By means of a arranged in the two edge regions U-shaped part, the two housing parts are electrically isolated from each other.

In addition, the describes DE 10 2011 109 179 A1 a single cell for a battery and a battery. The single cell comprises two housing parts, a cell frame, an electrode foil stack arranged between the housing parts and at least one insulation element arranged between the housing parts. By means of the insulating element, the housing parts are electrically separated from each other, wherein the insulating element has dimensions such that it protrudes at least partially in the assembled state of the single cell, a first housing part at the edge forming a supernatant. In this case, the first housing part of the insulating element at the edge is at least partially wrapped.

The invention has for its object to provide a comparison with the prior art improved method for producing a single cell for an electrochemical energy storage, a single cell prepared by such a method and an electrochemical energy storage with a number of such single cells.

The object is achieved with respect to the method by the in claim 1, with respect to the single cell by the in claim 6 and in terms of the electrochemical energy storage device by the features specified in claim 9.

Advantageous embodiments of the invention are the subject of the dependent claims.

An inventive method for producing a single cell for an electrochemical energy storage, wherein the single cell comprises a cell housing of two housing parts, provides that an edge region of at least one first housing part is at least partially cold-formed after a juxtaposition of the housing parts such that a positive and / or or non-positive connection between the two housing parts is made.

The fact that the two housing parts are positively and / or non-positively connected with each other, a known from the prior art hot pressing method, also known under the term heat sealing method, not required. Since the individual cell is not exposed to the comparatively high temperatures during the hot pressing process by means of the method according to the invention for the closure of the cell housing, the risk of damage to a comparatively sensitive cell chemistry can be substantially reduced. In turn, a lifetime of the single cell can be increased.

In addition, a process step of activation of the areas of the housing parts can be omitted, which are bonded by means of a sealing material cohesively.

In one embodiment, the edge region of the first housing part is designed such that this edge region can be inserted into an edge region of a second housing part and is widened after insertion by cold forming. Since the edge region of the first housing part is inserted into the edge region of the second housing part, the first housing part is prefixed for the process of cold forming. The housing parts can thus be aligned and positioned with each other.

In one possible embodiment, the edge regions of both housing parts are each groove-shaped, and the groove-shaped edge region of the first housing part inserted into the groove-shaped edge region of the second housing part is widened after insertion by cold forming. By means of the groove shape of the edge regions, the two housing parts are circumferentially encircling after the cold forming and thus connected to one another in a form-fitting and / or non-positively connected manner.

One embodiment of the method provides for the second housing part to be arranged in a die for the positive and / or non-positive closure of the single cell, the edge region of the first housing part to be inserted into the edge region of the second housing part, and the edge region of the first housing part to be secured by means of a stamp Direction of the edge region of the second housing part is pressed. Advantageously, the die is formed such that the housing parts when force by means of the punch side be supported, so that the risk of unwanted formations is at least significantly reduced.

In another possible embodiment, an insulating element is arranged between these before insertion of the edge region of the first housing part in the edge region of the second housing part. By means of the insulating element, the two housing parts are in the assembled state of the single cell advantageously electrically insulated from each other.

Furthermore, the invention relates to a single cell, which is prepared by the method described above. According to the invention the housing parts by cold forming at least one of the edge regions of a housing part positively and / or non-positively connected.

In a development of the single cell, the edge regions of both housing parts are groove-shaped. In this case, the edge regions are formed in a groove shape such that the edge regions at least partially correspond with one another and thus the edge region of the first housing part can be inserted into the edge region of the second housing part for mounting the cell housing.

At least between the two edge regions, in a further embodiment, at least one insulating element is arranged, by means of which the two housing parts are advantageously electrically insulated from one another.

In addition, the invention relates to an electrochemical energy storage with a number of such electrically connected in series and / or parallel single cells.

In particular, the electrochemical energy store is provided for arrangement in a vehicle. It is a vehicle battery, in particular a traction battery for an electric vehicle, a hybrid vehicle or a vehicle powered by fuel cells.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

1 1 is a schematic sectional view of an enlarged detail of a cell housing of a single cell prior to assembly;

2 FIG. 2 schematically a perspective sectional view of an enlarged section of the cell housing after assembly; FIG.

3 schematically a perspective sectional view of the cell housing,

4 2 is a schematic sectional view of an enlarged section of housing parts arranged in a forming device;

5 schematically a perspective sectional view of fastened together housing parts,

6 schematically a perspective sectional view of an enlarged section of the housing parts fastened to each other, and

7 schematically a sectional view of the attached housing parts.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows a sectional view of an enlarged section of a single cell 1 for an electrochemical energy storage.

The electrochemical energy store comprises a plurality of such individual cells 1 , which are electrically connected in series and / or parallel to each other. The electrochemical energy store i is arranged as a vehicle battery for arrangement in a vehicle. The vehicle battery serves as a traction battery, wherein the vehicle is an electric vehicle, a hybrid vehicle or a fuel cell powered vehicle.

The single cell 1 is designed as a bipolar Rahmenflachzelle, wherein the single cell 1 a cell case 2 with two housing parts 2.1 . 2.2 , an electrode assembly, not shown, and an insulation element 3 includes.

In this embodiment, the single cell 1 form the two housing parts 2.1 . 2.2 the electrical poles of the single cell 1 , wherein the housing parts 2.1 . 2.2 by means of the insulating element 3 are electrically isolated from each other.

Here is a first housing part 2.1 cupped and a second housing part 2.2 formed substantially planar.

Usually, the two housing parts 2.1 . 2.2 in their peripheral areas 2.1.1 . 2.2.1 cohesively connected to each other, for which purpose the insulation element 3 in a hot pressing process is partially melted and the two edge areas 2.1.1 . 2.2.1 the housing parts 2.1 . 2.2 when cooling a material of the insulation element 3 and connect under effective pressing force.

In the hot-pressing method, which is also known as a heat-sealing method, a comparatively high temperature is set, which acts on a cell chemistry, ie on the electrode assembly, whereby there is a risk of damage to the same.

In addition, the cohesive connection of the two edge regions 2.1.1 . 2.2.1 an activation of joint surfaces of the border areas 2.1.1 . 2.2.1 required.

At least to reduce the risk of damage to the electrode assembly in the closure of the cell housing 2 the single cell 1 and for reducing process steps to close the cell housing 2 is provided, the two housing parts 2.1 . 2.2 by means of a cold forming positively and / or non-positively fastened to each other.

These are the peripheral edge areas 2.1.1 . 2.2.1 the two housing parts 2.1 . 2.2 groove-shaped, wherein the groove-shaped edge regions 2.1.1 . 2.2.1 in cross section in the sectional view, inter alia in 1 have a cup shape.

In addition to the groove-shaped formation of the edge regions 2.1.1 . 2.2.1 the housing parts 2.1 . 2.2 is also a peripheral border area 3.1 of the insulation element 3 groove-shaped.

The groove-shaped edge area 2.1.1 of the first housing part 2.1 points to one of the edge area 2.2.1 of the second housing part 2.2 facing bottom region two bulges A, so that the bottom portion is formed in the sectional view substantially meandering.

The border area 2.2.1 of the second housing part 2.2 and the border area 3.1 of the insulation element 3 have a substantially flat in the sectional view bottom area.

Here are the border areas 2.1.1 . 2.2.1 and 3.1 shaped such that the edge area 2.1.1 of the first housing part 2.1 in sections in the border area 3.1 of the insulation element 3 and this at least partially in the border area 2.2.1 of the second housing part 2.2 can be arranged.

In 2 is a perspective view of a sectional view of an enlarged section of the nested edge regions 2.1.1 . 2.2.1 . 3.1 shown, where 3 a perspective sectional view of the cell housing 2 shows.

4 shows a forming device 4 for cold forming for closing the single cell 1 , In particular for the positive and / or non-positive Aneinanderbefestigung of the two housing parts 2.1 . 2.2 ,

The forming device 4 includes a die 5 , two hold downs 6 and a stamp 7 ,

For closing the single cell 1 , ie to the closure of the cell housing 2 becomes the second housing part 2.2 with the arranged in this isolation element 3 into the matrix 5 the forming device 4 inserted. Here is the border area 3.1 of the insulation element 3 in sections in the border area 2.2.1 of the second housing part 2.2 arranged.

The matrix 5 supports the second housing part 2.2 and in particular its edge area 2.2.1 from below, whereas the matrix 5 in the horizontal direction R is at least elastically deformable.

In addition, the die is 5 formed such that the first housing part 2.1 is supported laterally, wherein the die 5 in a first housing part 2.1 assigned portion substantially does not have the property of elastic deformability.

To a position of the housing parts 2.1 . 2.2 and the insulating element arranged between them 3 ensure the hold-downs are 6 provided by means of which the housing parts 2.1 . 2.2 are largely fixed.

The border area 2.1.1 of the first housing part 2.1 serves to receive the stamp 7 , where the edge area 2.1.1 of the first housing part 2.1 by means of the stamp 7 in the vertical direction R1 of the edge region 2.2.1 of the second housing part 2.2 is pressed.

Alternatively or additionally, it may be provided that the edge area 2.1.1 of the first housing part 2.1 from the outside in the vertical direction R1 in the edge region 2.2.1 of the second housing part 2.2 is pressed.

By a force, in particular on the edge area 2.1.1 of the first housing part 2.1 in the vertical direction R1 of the second housing part 2.2 and in that the first housing part 2.1 by means of the hold down 6 above the die 5 is fixed, with the die 5 in the horizontal direction R is elastically deformable, the material, in particular the edge region 2.1.1 of the first housing part 2.1 pushed away in horizontal direction R.

The Stamp 7 acts on the two bulges A in the bottom area of the edge area 2.1.1 of the first housing part 2.1 which side, is pushed away in the horizontal direction R according to the present embodiment.

As a result, the shapes of the edge areas adapt 2.1.1 . 2.2.1 the housing parts 2.1 . 2.2 to each other. The two housing parts 2.1 . 2.2 jam together so that the first housing part 2.1 with its edge area 2.1.1 positive and non-positive, the second housing part 2.2 , in particular its edge area 2.2.1 connected is.

To allow the shapes of the border areas 2.1.1 . 2.2.1 Matching each other, are material properties of the housing parts 2.1 . 2.2 , in particular the border areas 2.1.1 . 2.2.1 in terms of strength and expansion coefficient matched.

For example, a housing part 2.1 . 2.2 made of aluminum and the other housing part 2.2 . 2.1 made of copper. Alternatively, the housing parts 2.1 . 2.2 or can one of the two housing parts 2.1 . 2.2 be formed of copper-clad aluminum.

In addition, the insulating element has 3 in addition to a chemical resistance also a corresponding stability.

A position of a joint between the housing parts 2.1 . 2.2 can be on the side of the single cell 1 So their cell case 2 be chosen freely. In particular, a depth of the edge areas 2.1.1 . 2.2.1 the two housing parts 2.1 . 2.2 freely selectable.

The 5 to 7 each show a sectional view of the positive and non-positively connected housing parts 2.1 . 2.2 ,

To a maximum possible stiffness of the edge area 2.2.1 of the second housing part 2.2 To be able to ensure, the junction of the two border areas 2.1.1 . 2.2.1 below a bottom of the second housing part 2.2 be arranged. This results in an additional lateral space reduction, with a supernatant thus formed a thickness of the cell housing 2 elevated. This in turn increases a longitudinal extent of one of a plurality of such individual cells 1 formed cell block as part of the electrochemical energy storage.

In one possible embodiment, this projection formed by means of the molding can be used to contact individual cells arranged side by side 1 be used.

It is also possible that the insulation element 3 in the bottom area of its edge area 3.1 and the second housing part 2.2 in the bottom area of its edge area 2.2.1 Bulges A has, whereby a relatively large undercut can be generated with respect to the positive and non-positive connection.

LIST OF REFERENCE NUMBERS

1

single cell

2

cell case

2.1

first housing part

2.1.1

border area

2.2

second housing part

2.2.1

border area

3

insulation element

3.1

border area

4

reshaping

5

die

6

Stripper plate

7

stamp

A

bulge

R

horizontal direction

R1

vertical direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2006/0141356 A1 [0002]
• DE 102011109179 A1 [0003]

Claims (10)

Method for producing a single cell ( 1 ) for an electrochemical energy store, wherein the single cell ( 1 ) a cell housing ( 2 ) of two housing parts ( 2.1 . 2.2 ), characterized in that an edge region ( 2.1.1 ) at least a first housing part ( 2.1 ) after a juxtaposition of the housing parts ( 2.1 . 2.2 ) is at least partially so cold formed that a positive and / or non-positive connection between the two housing parts ( 2.1 . 2.2 ) will be produced. Method according to claim 1, characterized in that the edge region ( 2.1.1 ) of the first housing part ( 2.1 ) is formed such that this edge region ( 2.1.1 ) into a border area ( 2.2.1 ) of a second housing part ( 2.2 ) and extended after insertion by cold forming. Method according to claim 1 or 2, characterized in that the edge regions ( 2.1.1 . 2.2.1 ) of both housing parts ( 2.1 . 2.2 ) are each groove-shaped, and in the groove-shaped edge region ( 2.2.1 ) of the second housing part ( 2.2 ) used groove-shaped edge region ( 2.1.1 ) of the first housing part ( 2.1 ) is extended after insertion by cold forming. A method according to claim 2 or 3, characterized in that for the positive and / or non-positive closure of the single cell ( 1 ) the second housing part ( 2.2 ) in a die ( 5 ), the edge area ( 2.1.1 ) of the first housing part ( 2.1 ) in the border area ( 2.2.1 ) of the second housing part ( 2.2 ) is used and the edge area ( 2.1.1 ) of the first housing part ( 2.1 ) by means of a stamp ( 7 ) in the vertical direction (R1) of the edge region ( 2.2.1 ) of the second housing part ( 2.2 ) is pressed. Method according to one of the preceding claims, characterized in that before an insertion of the edge region ( 2.1.1 ) of the first housing part ( 2.1 ) in the border area ( 2.2.1 ) of the second housing part ( 2.2 ) between these an insulation element ( 3 ) is arranged. Single cell ( 1 ) produced by a method according to one of the preceding claims, characterized in that the housing parts ( 2.1 . 2.2 ) by cold forming at least one of the edge regions ( 2.1.1 . 2.2.1 ) of a housing part ( 2.1 . 2.2 ) are positively and / or non-positively connected. Single cell ( 1 ) according to claim 6, characterized in that the edge areas ( 2.1.1 . 2.2.1 ) of both housing parts ( 2.1 . 2.2 ) are groove-shaped. Single cell ( 1 ) according to claim 6 or 7, characterized in that at least between the two edge regions ( 2.1.1 . 2.2.1 ) at least one isolation element ( 3 ) is arranged. Electrochemical energy storage with a number of electrically connected in series and / or parallel single cells ( 1 ) according to one of claims 6 to 8. Electrochemical energy store according to claim 9, which is intended to be arranged in a vehicle.

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