DE102008059944B4 - Single cell battery, method of making the battery and its use - Google Patents

Abstract

Battery with individual cells (1) connected in series and / or in parallel, wherein the single cell (1) is formed in each case from an electrode stack (6) whose individual electrodes (6.1, 6.2) of different polarity are separated from one another by a separator (6.3) are, wherein electrodes (6.1, 6.2) of the same polarity electrically conductively connected to a pole (P1, P2) and the poles (P1, P2) of the electrode stack (6) are each electrically connected to an electrically conductive housing side wall (3, 4) , wherein the electrodes (6.1) of the anode made of aluminum, the electrodes (6.2) of the cathode of copper and the housing side walls (3, 4) are formed of aluminum, wherein the housing side wall (4) facing the pole formed as a cathode (4) on the inside a metallic intermediate layer (7), characterized in that the individual cells (19) for discharging during the operation of the battery generated heat loss conductively with a heat he heat-conducting plate are connected and that the housing side walls (3,4) on a side facing the heat conduction in each case at least in sections via the ...

Description

The invention relates to a battery with serial and / or parallel interconnected individual cells according to the preamble of claim 1 and a method for producing a battery with serial and / or parallel interconnected individual cells according to the preamble of claim 11 and the use of the battery according to claim 19 ,

According to the prior art are high-voltage batteries, z. As lithium-ion batteries, known for vehicle applications, which are constructed in particular of several electrically connected in series and / or parallel single cells. In bipolar single cells, the electrical contacts, d. H. a plus and a minus pole, be placed directly on against each other electrically insulated parts of the housing.

The JP 102 08 710 A1 discloses such a single electrical cell, in particular a flat cell comprising an electrode stack which is formed of a positive electrode and a negative electrode, wherein between the positive and the negative electrode, a separator is arranged. The positive electrode consists of an electrical conductor, a binder and an electrolyte. On the other hand, the negative electrode is formed of carbon particles, a binder and an electrolyte. The electrode stack is disposed between a positive current collector and a negative current collector, the positive current collector being a flat plate, the inside of which is made of aluminum and the outside of which is made of stainless steel. The negative current collector is also a flat plate whose inside is made of copper, iron or nickel and the outside of which is also made of stainless steel. The respective edge surfaces of the negative and positive Stormkollektors are connected to a resin frame, in particular fused.

The DE 10 2007 063 181 A1 discloses a single cell for a battery having an electrode stack disposed within a cell housing and a method of manufacturing the same. The individual electrodes or the electrode films are electrically conductively connected to current discharge lugs, wherein at least electrodes of different polarity are electrically separated from one another by a separator or a separator foil, wherein the current discharge lugs of the same polarity are electrically conductively connected to one another. The current discharge lugs of a pole are electrically conductively pressed together and / or welded.

The DE 102 19 424 A1 discloses that, in a galvanic element with thin electrodes in a housing formed of sealed plastic films, at least one of the plastic films on a side facing the electrodes is metallized such that the metallization on the one hand forms the electrical contact with the electrode and on the other hand, the outer contact lug of the electrode , The plastic film may be a composite film with an inner, covered on both sides of plastic films metal foil and the metallization of the plastic film may be formed in the area lying outside the cell outline as conductor tracks.

The invention has for its object to provide a comparison with the prior art improved battery and an improved over the prior art method for their preparation.

With regard to the battery, the object is achieved by the features specified in claim 1 and in terms of the method by the features specified in claim 11.

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

The object of the invention is in a battery with single cells with serial and / or parallel interconnected single cells, wherein the single cell is formed in each case from an electrode stack whose individual electrodes of different polarity, separated by a separator from each other, wherein electrodes of the same polarity electrically conductive connected to a pole and the poles of the electrode stack are each electrically connected to an electrically conductive housing side wall, wherein the electrodes of the anode made of aluminum, the electrodes of the cathode of copper and the housing side walls are formed of aluminum, wherein the pole formed as a cathode facing Housing side wall on the inside has a metallic intermediate layer, achieved in that the individual cells for dissipation during operation of the battery generated heat loss conductively connected to a heat conducting plate and that di e housing side walls on one of the heat-conducting plate facing side in each case at least in sections along the length of the individual cell outgoing side wall element, which is angled towards the respective housing side wall in the direction of the cell interior.

This intermediate layer allows a material and procedural simple electrical connection of the formed as a cathode and made of copper pole to the housing side wall formed from the anode material aluminum. This results in an advantageous manner that the Housing side walls can be formed from the same material, which in particular leads to the advantage that in an electrical interconnection of the individual cells to the battery between the housing side walls directly adjacent single cells no so-called local elements arise and thus the risk of corrosion of the housing side walls and a resulting reduction the electrical conductivity between these can be avoided.

According to a preferred embodiment of the battery according to the invention, the intermediate layer is arranged at least in the region of the pole formed as a cathode, which leads to a low material and manufacturing costs and as a result to low production costs.

The intermediate layer is formed according to various embodiments of a film and / or formed as a plate, so that a layer thickness of these is individually predetermined.

In a special way, an edge region of the respective electrode foil, which is guided to the outside of the electrode stack, is provided to form the poles as a current collector tab, thereby eliminating the need for complex contacting of the electrode foil and the current collector tab. At the same time, this type of contacting is very safe against at least many, especially external influences such as shock or vibration. This led to the outside of the respective electrode foil edge region is not coated with the anode or the cathode material due to the electrical connection to the pole.

In a preferred development of the invention, a cell housing of the single cell comprises two housing side walls, between which an edge-surrounding and electrically insulating frame is arranged. By an arrangement of the electrode stack in the peripherally encircling, in particular electrically insulating frame, an additional insulating arrangement can be advantageously saved. Furthermore, the handling of the single cell is made easier or safer.

In an advantageous embodiment of the invention, the Stromableiterfahnen or the poles are pressed with the housing side walls. The compression is a simple electrical connection between the poles and the housing side walls and is preferably carried out in a joint operation with the attachment of the housing side walls to the frame.

Alternatively or additionally, the current discharge lugs or the poles are welded to the housing side walls. The resulting cohesive connection produces an electrically conductive connection with a low contact resistance, which has a high current-carrying capacity.

The object of the invention is in a method for producing a battery with serial and / or parallel interconnected single cells, wherein the single cell is formed in each case from an electrode stack whose individual electrodes of different polarity, by a separator are separated from each other insulating, wherein electrodes of the same polarity electrically conductively connected to one another to a pole and the poles of the electrode stack are each electrically connected to an electrically conductive housing side wall, wherein the electrodes of the anode of aluminum, the electrodes of the cathode formed of copper and the housing side walls are formed of aluminum, wherein on an inner side the housing side wall facing the pole formed as a cathode, an intermediate layer formed of copper or nickel is applied, achieved in that in the battery, a heat conduction is introduced and the housing side walls with a em on one of the heat conducting plate side facing at least in sections over the length of the single cell outgoing sidewall element are formed, which is angled towards the respective housing side wall in the direction of the cell interior.

In this case, the intermediate layer is compressed and / or welded, in particular when formed as a plate with the pole formed as a pole facing side wall so that between the housing side wall and the intermediate layer a cohesive and electrically connected with a low contact resistance.

In order to produce particularly thin layers and thus perform the single cells as small as possible, the intermediate layer is printed in a preferred embodiment of the method according to the invention as a film on the housing side wall, rolled or applied electrochemically.

The generation of the electrically conductive connection of the poles with the housing side walls are pressed together and / or pressed together, wherein during the welding process, one or more welds and / or welds are generated. Preferably, in the welding process, the housing side wall and further in the depth of the pole forming Stromableiterfahnen the electrode stack partially melted, so that with a weld and / or a weld all the poles forming Stromableiterfahnen and the corresponding electrically conductive housing side wall are welded together in particular in one step.

A cell housing of the single cell is formed from two electrically conductive housing side walls, wherein between the housing side walls a peripherally rotating and electrically insulating frame is arranged, in which the electrode stack is inserted.

The attachment of the housing side walls to the frame is preferably produced by means of positive, material and / or non-positive connections, for example by means of adhesive and / or welded joints, so that the housing is formed liquid and / or gas-tight in an advantageous manner and thus the electrode stack is protected from external mechanical and chemical influences.

By one or more of the measures mentioned, it is possible to simplify the construction of a cell housing of the single cell at a low-cost production, to increase the vibration safety and thus the stability, the lifetime and, in turn, also the variety of uses. Furthermore, the current carrying capacity is improved by the cohesive contacting of the current collector lugs to form the pole contacts and the cohesive connection of these with the housing side walls. There is also no weakening of the pressure tightness of the cell housing of the single cell, since no contact implementation of the pole contacts.

The single cell according to the invention is intended in particular for use in a battery, wherein a plurality of individual cells are electrically connected in series and / or parallel to one another in order to advantageously adapt the properties of the battery to a purpose of use.

Furthermore, due to its properties, the single cell is in particular suitable for use in a battery of a vehicle, wherein in turn a plurality of individual cells are electrically connected in series and / or in parallel with one another. The vehicle is in particular a hybrid vehicle or an electric vehicle.

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

Showing:

1 3 is an exploded view of a single cell with an electrode stack, two housing side walls and a frame arranged between them, FIG.

2 schematically an exploded view of the single cell according to 1 in which a pole of the electrode stack designed as a cathode is connected to a housing side wall, and

3 schematically an enlarged detail of a joint between the cathode formed as the pole of the electrode stack, the intermediate layer and the housing side wall according to 2 ,

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

In 1 is a single cell 1 , In particular, a lithium-ion single cell, shown, the cell housing 2 from two housing side walls 3 and 4 and an arranged between these, peripherally encircling and electrically insulating frame 5 , z. B. a plastic frame is formed.

To produce a battery, not shown, more of the individual cells 1 connected in series and / or in parallel with each other electrically, wherein in a series connection, an electrical connection of the individual cells 1 by contacting the housing side walls 3 . 4 directly adjacent single cells 1 is reached.

The from the several single cells 1 The battery formed additionally preferably comprises a heat-conducting plate, wherein the individual cells 1 to a derivative of a during operation of the battery, in particular during a charging and discharging process, this generated heat loss conductively connected to the heat conducting plate.

In order to achieve an increase in the heat transfer to the heat conducting plate, the housing side walls 3 . 4 on a side facing the heat conduction in each case at least partially over the length of the respective individual cell 1 outgoing sidewall element 3.1 respectively. 4.1 on, the opposite of the respective housing side wall 3 . 4 is angled towards the cell interior.

Since the heat conducting plate is preferably made of a very good thermal conductivity and therefore in particular of a metallic material, is between the individual cells 1 and the heat conducting plate is preferably an electrically insulating and thermally conductive material, such as a heat conducting, introduced.

Furthermore, the heat-conducting plate for a high heat output is preferably flowed through by a cooling medium, for example a refrigerant of a vehicle air conditioning system, wherein the heat-conducting plate has connection elements for integration into such a cooling circuit.

In the cell case 2 especially in the frame 5 the single cell 1 , is according to the 2 and 3 an electrode stack 6 arranged, whose individual electrodes 6.1 . 6.2 different polarity, preferably electrode films, through a separator 6.3 , In particular a Separatorfolie are isolated in isolation. Here are the electrodes 6.1 the anode of aluminum and the electrodes 6.2 the cathode is made of copper.

The electrodes 6.1 . 6.2 are further each coated with an electrochemically active anode material or cathode material. Since it is the single cell 1 In particular, is a lithium-ion single cell, possible anode materials such as graphite, nanocrystalline, amorphous silicon or lithium titanate. As cathode materials, inter alia, lithium cobalt oxide, lithium nickel oxide or lithium iron phosphate can be used.

One to outside the electrode stack 6 guided edge region of the respective electrode 6.1 . 6.2 or electrode film, which is not coated with the anode or cathode material, respectively forms a Stromableiterfahne, wherein Stromableiterfahnen one polarity are electrically connected to one another to a pole P1 or P2.

These poles P1 and P2 of the electrode stack 6 are each electrically with a housing side wall 3 respectively. 4 connected. The housing side walls 3 . 4 are electrically conductive and formed of a metal.

For an electrical connection of the individual cells 1 to the battery may be between housing side walls 3 . 4 , which are made of different materials, such as copper and aluminum, form so-called local elements, which in turn to corrosion of the housing side walls 6.1 . 6.2 and an increase in contact resistance can lead. For this reason, the invention provides that both housing side walls 3 . 4 are made of the same material, in particular aluminum, since this is lighter and less expensive than copper.

To a simple and low-loss electrical connection of the formed as a cathode pole P2 to the housing side wall 4 to allow, is further provided according to the invention, that between the pole P2 and the housing side wall 4 a metallic intermediate layer 7 is arranged, which is like the pole P2 made of copper or alternatively made of nickel.

In the illustrated embodiment of the invention, the intermediate layer 7 at least in the region of the pole formed as a cathode P2, in particular formed as a strip arranged. For example, the dimensions of the intermediate layer correspond 7 in about the dimensions of the pole P2, in particular covers the intermediate layer 7 the pole P2 completely. Thus, an optimal electrical connection of the pole P2 to the intermediate layer 7 and consequent to the housing side wall 4 achievable with a very low contact resistance at the same time low material and cost. This in turn results in a low total weight of the single cell 1 which is especially true when using one of several single cells 1 formed battery in a mobile application, preferably in a vehicle, leads to various benefits, such. As a low fuel consumption or improved weight distribution and consequent improved driving behavior in the vehicle.

In this case, the intermediate layer on the one hand be a plate, which in particular with the housing side wall 4 pressed and / or welded. The pressing and / or welding of the intermediate layer 7 with the housing side wall 4 are easy and inexpensive to implement and produce a material connection of the intermediate layer 7 with the housing side wall 4 , wherein due to the low contact resistance electrical losses are minimal.

On the other hand, the intermediate layer 7 be formed of a film, which preferably on the housing side wall 4 rolled, printed or applied electrochemically. The thickness of the intermediate layer 7 preferably dimensioned such that this particular is sufficiently small and optimized to a small space height, but at the same time a simple and electrically optimal connection of the pole P2 to the intermediate layer 7 and thus to the housing side wall 4 allows. Furthermore, by the application of the film, a connection of the intermediate layer 7 over its entire surface to the housing side wall 4 achieved, so that a large current-carrying surface is created.

To form the cell case 2 become the housing side walls 3 and 4 material, positive and / or non-positive on the frame 5 attached. This attachment results in addition to the high stability, a dense version of the cell housing 2 , so that no foreign substances can penetrate into this. Furthermore, it is ensured that after fixing the housing side walls 3 . 4 on the frame 5 filled electrolyte can not escape and an environment of the single cells 1 damaged battery damages. To fill the electrolyte, the frame 5 Preferably, a filling opening, not shown, which can be closed after filling of the electrolyte.

Such a material, positive and / or non-positive attachment is carried out in a manner not shown z. B. by gluing, welding and / or fasteners to a high stability of the connection between the housing side walls 3 . 4 and the frame 5 to reach.

The fasteners are in particular rivets, the frame 5 at least at the edge embracing flag-like extensions of the housing side walls 3 . 4 and / or on the frame 5 molded holding elements. To produce a positive and / or non-positive connection, the housing side walls 3 . 4 and / or the frame 5 preferably not shown in detail, corresponding to the respective connecting elements forms or recesses.

Also a connection of the housing side walls 3 . 4 by means of a hot pressing process is possible, with areas of the frame 5 melted at least on the surface and thus with the housing side walls 3 . 4 get connected.

From the material, positive and / or non-positive attachment of the housing side walls 3 . 4 on the frame 5 In addition to the high stability results in a dense design of the cell housing, so that no foreign matter can penetrate into this. Furthermore, it is ensured that after fixing the housing side walls 3 . 4 on the frame 5 filled electrolyte can not escape and an environment of the single cells 1 formed, not shown damaged battery. To fill the electrolyte, the frame 5 Preferably, a filling opening, not shown, which can be closed after filling.

By attaching the housing side walls 3 . 4 on the frame 5 are the poles P1 and P2 of the electrode stack 6 preferably with the housing side walls 3 . 4 and on the cathode side with the intermediate layer 7 pressed, so that an electrical connection between the poles P1 and P2 and the associated housing side walls 3 . 4 is trained.

Alternatively or additionally, it is possible to connect the poles P1 and P2 to the housing side walls 3 . 4 to weld, during welding one or more welds and / or welds are generated. Preferably, in the welding, the housing side walls 3 . 4 and further in the depth of the poles P1, P2 forming Stromableiterfahnen the electrode stack 6 and the cathode side, the intermediate layer partially melted, so that with a weld and / or a weld all the poles P1, P2 forming Stromableiterfahnen and the corresponding electrically conductive housing side wall 3 or 4 in particular welded together in one step.

According to a continuation of the invention, not further illustrated, the current collector tabs are in a separate process prior to the generation of the electrically conductive connection with the housing side walls 3 . 4 pressed to the poles P1, P2 and / or welded.

2 shows the single cell 1 according to 1 , wherein the cathode formed as a pole P2 of the electrode stack 6 electrically with the housing side wall 4 connected is. This electrical connection is in particular before the attachment of the housing side walls 3 . 4 on the frame, preferably by means of a welding process, wherein the pole P2 is formed with the intermediate layer formed of copper or nickel 7 is welded.

3 shows the joint between the formed as a cathode pole P2 of the electrode stack 6 , the intermediate layer 7 and the housing side wall 4 in an enlarged detail, which in addition to the connection of the pole P2 to the intermediate layer 7 and thus the housing side wall 4 the arrangement of the individual electrodes 6.1 and 6.2 and the separator arranged between them 6.3 clarify.

LIST OF REFERENCE NUMBERS

1

single cell

2

cell case

3

Housing sidewall

3.1

Side wall member

4

Housing sidewall

4.1

Side wall member

5

frame

6

electrode stack

6.1

electrode

6.2

electrode

6.3

separator

7

interlayer

P1

pole

P2

pole

Claims (19)

Battery with serial and / or parallel interconnected single cells ( 1 ), whereby the single cell ( 1 ) each from an electrode stack ( 6 ) is formed, whose individual electrodes ( 6.1 . 6.2 ) of different polarity, by a separator ( 6.3 ) are insulated from each other, wherein electrodes ( 6.1 . 6.2 ) of the same polarity are electrically connected to one another to a pole (P1, P2) and the poles (P1, P2) of the electrode stack ( 6 ) each electrically connected to an electrically conductive housing side wall ( 3 . 4 ), the Electrodes ( 6.1 ) of the anode made of aluminum, the electrodes ( 6.2 ) the copper cathode and the housing sidewalls ( 3 . 4 ) are formed of aluminum, wherein the cathode side designed as a pole (P2) side wall ( 4 ) inside a metallic intermediate layer ( 7 ), characterized in that the individual cells ( 19 ) heat dissipated during operation of the battery loss heat heat are connected to a heat conducting plate and that the housing side walls ( 3 . 4 ) in each case at least in sections over the length of the single cell on a side facing the heat-conducting plate ( 1 ) outgoing side wall element ( 3.1 . 4.1 ), which relative to the respective housing side wall ( 3 . 4 ) is angled towards the cell interior. Battery with single cells ( 1 ) according to claim 1, characterized in that the intermediate layer ( 7 ) is arranged at least in the region of the pole formed as a cathode (P2). Battery with single cells ( 1 ) according to claim 1, characterized in that the intermediate layer ( 7 ) is formed of a film. Battery with single cells ( 1 ) according to claim 1, characterized in that the intermediate layer ( 7 ) is formed as a plate. Battery with single cells ( 1 ) according to claim 1, characterized in that an outward of the electrode stack ( 6 ) guided edge region of the respective electrode foil ( 6.1 . 6.2 ) forms a Stromableiterfahne, wherein the Stromableiterfahnen a polarity are electrically connected to one another to a pole (P1, P2). Battery with single cells ( 1 ) according to claim 1, characterized in that a cell housing ( 2 ) two housing side walls ( 3 . 4 ), between which an edge peripheral and electrically insulating frame ( 5 ) is arranged. Battery with single cells ( 1 ) according to claim 1, characterized in that the poles (P1, P2) of the electrode stack ( 6 ) with the housing side walls ( 3 . 4 ) are pressed and / or welded. Battery with single cells ( 1 ) according to one of claims 1 to 7, characterized in that the electrodes ( 6.1 . 6.2 ) having different polarity with an anode material or a cathode material coated electrode films. Battery with single cells ( 1 ) according to one of claims 1 to 8, characterized in that the separator ( 6.3 ) is a Separatorfolie. Battery with single cells ( 1 ) according to one of claims 1 to 9, characterized in that the intermediate layer ( 7 ) is formed of copper or nickel. Method for producing a battery with individual cells connected in series and / or in parallel ( 1 ), whereby the single cell ( 1 ) each from an electrode stack ( 6 ) whose individual electrodes ( 6.1 . 6.2 ) of different polarity, by a separator ( 6.3 ) are isolated from each other, wherein electrodes ( 6.1 . 6.2 ) of the same polarity are electrically connected to one another to a pole (P1, P2) and the poles (P1, P2) of the electrode stack ( 6 ) each electrically connected to an electrically conductive housing side wall ( 3 . 4 ), the electrodes ( 6.1 ) of the anode made of aluminum, the electrodes ( 6.2 ) the cathode is formed of copper and the housing side walls ( 3 . 4 ) are formed of aluminum, wherein on an inner side of the cathode-side formed as a pole (P2) side wall ( 4 ) an intermediate layer formed of copper or of nickel ( 7 ) is applied, characterized in that in the battery, a heat conducting plate is introduced and the housing side walls ( 3 . 4 ) with a side facing the heat conducting plate in each case at least in sections over the length of the individual cell ( 1 ) outgoing side wall element ( 3.1 . 4.1 ) are formed, which relative to the respective housing side wall ( 3 . 4 ) is angled towards the cell interior. Method according to claim 11, characterized in that the intermediate layer ( 7 ) with the cathode side formed as a pole (P2) facing housing side wall ( 4 ) is pressed and / or welded. Method according to claim 11, characterized in that the intermediate layer ( 7 ) on the cathode side designed as a pole (P2) facing the housing side wall ( 4 ) is printed, rolled or applied electrochemically. Method according to claim 11, characterized in that the housing side walls ( 3 . 4 ) and the poles (P1, P2) are pressed together and / or welded together for electrical connection. Method according to claim 11, characterized in that a cell housing ( 2 ) of two electrically conductive housing side walls ( 3 . 4 ) is formed, wherein between the housing side walls ( 3 . 4 ) a peripherally rotating and electrically insulating frame ( 5 ) is arranged. Method according to claim 11, characterized in that the housing side walls ( 3 . 4 ) shape-, material and / or non-positive on the frame ( 5 ) are attached. Method according to one of claims 11 to 16, characterized in that on the electrodes ( 6.1 . 6.2 ) of different polarity with an anode material or a cathode material coated electrode films ( 6.3 ) are applied. Method according to one of claims 11 to 17, characterized in that the separator ( 6.3 ) is formed as a separator film. Using a battery with single cells ( 1 ) according to one of claims 1 to 10 for a hybrid vehicle or an electric vehicle.

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