DE102014213682A1 - Energy storage with improved sealing - Google Patents

Abstract

The present invention relates to a battery comprising a battery housing (18), wherein the battery housing (18) has a contacting opening, wherein an electrical contact for tapping electrical energy from the battery (10) passes through the contacting opening, wherein the interior of the battery housing (18 ) is sealed against the contacting opening by a seal (34) disposed between a first and a second battery component, the seal (34) having a first leg (60) extending from the first battery component to the second battery component and one each with the first battery component first and second battery component contacting first sealing region (61, 61 '), and wherein the seal (34) further comprises a second leg (62, 62'), one with the first battery component or with the second battery component in contact engageable second sealing region (63, 63 '), wherein the second leg (62, 62 is) ruling by a (inside of the battery case 18) pressure deformable such that the contact pressure of the second sealing region (63, 63 ') to which the second battery device is increased first or. The above-described battery (10) makes it possible in a cost-effective manner to realize a particularly well-defined and long-term stable sealing of a battery housing (18) in particular with respect to a contact feedthrough.

Description

The present invention relates to an energy storage, such as a lithium-ion battery. The present invention relates in particular to an energy store with an improved sealing of a battery housing.

State of the art

Electrochemical energy storage devices, such as lithium-ion batteries, are widely used in many daily applications. They are used, for example, in computers such as laptops, mobile phones, smart phones, and other applications. Even with the currently highly advanced electrification of vehicles, such as motor vehicles, such batteries offer advantages.

Lithium-ion batteries, for example, are often arranged in a housing, with an electrical contact for tapping electrical energy from the interior of the housing through an opening of the housing. It is important to securely seal the opening for conducting the electrical contact through the housing.

From the document US 2010/0021811 A1 a battery is known, which has a battery container, a lid body and a connection. The connection extends through the lid, wherein an insulating element is arranged between the lid and the connection.

The document JP 2012-049076 describes a battery lid through which passes an electrode terminal. In order to achieve a sealing effect, an embodiment is likewise provided, in which a seal is provided between the cover and the electrical connection.

Disclosure of the invention

The present invention is a battery, comprising a battery housing, wherein the battery housing has a contacting opening, wherein the contact opening through an electrical contact for tapping electrical energy from the battery, wherein the interior of the battery housing against the contacting opening by a between a first and a sealed second fluid component seal, wherein the seal has a first leg which extends from the first battery component to the second battery component and each having a first sealing area in contact with the first and the second battery component, and wherein the seal further comprises a second leg which has a second sealing region which can be brought into contact with the first battery component or with the second battery component, wherein the second leg deforms in such a way by a pressure prevailing in the interior of the battery housing bar is that the contact pressure of the sealing region of the second leg is increased to the first or the second battery component.

The above-described battery allows in a cost effective manner to enable a particularly effective and durable tightness of the battery case or in particular an opening of the battery case for performing an electrical connection or an electrical contact.

As described above, the present invention relates to a battery. For the purposes of the present invention, a battery may be a primary battery or, advantageously, a secondary battery, such as in particular a rechargeable battery. For example, the battery may be a lithium-based battery, in particular a lithium-ion battery.

Such a battery has a battery case. The battery case may be configured, for example, from a plastic or metal. For example, the housing may also include an inflexible housing, also referred to as a hard case. The battery housing has a contacting opening, wherein an electrical contact for tapping electrical energy from the battery or a cell unit of the battery runs through the contacting opening. Under an electrical contact can be understood a component which can be contacted directly for tapping electrical energy or which serves as a housing feedthrough of the current path and is electrically conductively connected to the contact position and thus considered in the context of the present invention as the electrical contact.

Such a battery may have in the battery case, for example, one or a plurality of battery cells, which may be configured for example in a prismatic shape. In this case, in the interior of the housing there may be a flat-pressed winding, which comprises, for example, an aluminum foil and a copper foil, which are coated with reactive cathode materials or anode materials. Furthermore, two plastic foils designed approximately as diaphragms can be provided, which separate the anode and the cathode.

In order to realize an electrical contact of the cathode or the anode of the film roll, for example, the two as Cathode or designed as an anode foils are not accurately placed together, but are slightly offset in the direction of the winding axis. As a result, the negative voltage can be tapped off at an open narrow side of the coil, and the positive voltage of the respective foil or electrode at the other, opposite narrow side. The contacting can be realized, for example, with projecting foil strips with welded-strip-shaped metal strips, for example from the corresponding foil materials, the so-called current collectors. In this case, the current collectors can in turn be connected to the electrical contact, such as a connection bolt, or even be formed in such a way as to serve as a contact. The electrical contact or the connecting bolt can run through the housing or the contacting opening and serve as external contact of the electrodes, as explained above.

When producing such a battery, the housing can be filled with a liquid electrolyte after the introduction of the cell coil and in particular before a pressure-tight closure, for example through a closable opening which only needs to have a size in the range of 5 mm.

For example, to prevent leakage of the electrolyte and / or entry of air or moisture into the interior of the housing, the interior of the battery housing is sealed against the contacting opening by a seal disposed between a first and a second battery component. In other words, a seal is provided which seals a passage from the atmosphere surrounding the housing through the contacting opening into the interior of the housing. In this case, the seal between a first and a second battery component is arranged and thus does not need to touch the electrical contact directly.

The first and the second battery component and thus the gasket contacting battery components can basically be freely selected insofar as the seal can be arranged to seal the opening for performing the electrical contact or the battery housing arranged thereon, such as leakage of the electrolyte prevent the housing and / or entry of air or moisture into the interior of the housing. In this case, at least one of the first and second battery components expediently frame completely the opening for performing the electrical contact.

A gasket as described in detail above, in a battery as described above, has a first leg extending from the first battery component to the second battery component and each having a first sealing region in contact with the first and second battery components. As a result, the first leg can already form a first sealing stage by extending from the first battery component to the second battery component, and thus can already completely seal off a channel running from the interior of the housing to the external atmosphere.

The seal further includes a second leg having a second sealing area engageable with the first battery component or the second battery component. In this case, only a second leg may be provided, or it can be provided more than a second leg, wherein only one or more of the second leg can be configured as described below for a leg. The second leg can thus be brought into contact in particular with the first or the second battery component. When providing a plurality of second legs, they can thus be brought into contact with the first or the second battery component differently from each other. In addition, the second leg or the second leg is connected to the first leg, so that the seal can form a unitary compact component. By the second leg and in particular by the contact of a second sealing region and thus a sealing region of the second leg with the first battery component or with the second battery component, a second sealing stage can thus be made possible.

In this case, the second leg or the second legs are deformable by a pressure prevailing in the interior of the battery housing such that the contact pressure of at least the sealing area of the second leg, ie the second sealing area, is increased to the first or the second battery component. In other words, as a result of increased pressure in the interior of the housing, in particular with respect to the pressure which prevails in the atmosphere surrounding the housing, the second leg (s) is pressed at least partially with a greater force against the first or the second battery component become. Accordingly, the seal can be arranged in particular in such a way that the second leg (s) are directed towards the interior of the battery housing. In this case, an increase in the contact pressure mean that even without the pressure prevailing in the interior of the housing there is a certain contact pressure and this can be increased by the pressure prevailing in the interior of the housing, or that the corresponding Sealing region without the pressure prevailing in the interior of the housing is not applied to the first or the second battery component and the contact pressure is increased by the pressure in the interior of the housing such that it is present in the first place by the pressure inside the housing. This can be realized in principle by the provision of an attack surface on the second leg, which is aligned such that the pressure acts on this attack surface and can deform the second leg, for example, or only a pressure exerting enlargement of the contact pressure.

Such a configuration of a seal, in particular in the sealing of a housing interior in a contact bushing, has significant advantages over solutions known from the prior art.

On the one hand, the use of a previously described seal is a particularly cost-effective solution since the seal can be produced simply and thus inexpensively as an injection-molded part. Moreover, such a seal does not require a complex arrangement of the housing to be implemented in the housing. In contrast, the above-described seal can essentially replace an H-seal or double-lip seal known from the prior art, so that the energy store as such or the housing arrangement thereof need not be modified in order to use the seal. As a result, a battery described above can be manufactured substantially without complex changes to arrangements known from the prior art and by known methods.

In this case, the above-described seal, in particular when used for sealing a contact feedthrough of a battery, can produce a particularly reliable sealing effect. In detail seals are often introduced at this position under a pressing and thus about a compression of the first and the second battery component, so as to allow a secure sealing effect. A disadvantage of such compression, however, may be that too high a compression pressure can damage the seal, but too low a pressing pressure may not be sufficient to cause a secure sealing effect. Such highly accurate pressing is not necessary using a previously described seal. If appropriate, existing tolerances can be compensated automatically by the fact that increased by a compared to the outer atmosphere increased internal pressure of the battery, which may basically be present during operation of the energy storage, the contact pressure of the second leg or the second or the second sealing areas and the Sealing effect is thereby improved. In detail, can be effected by the internal pressure, which rests more material depending on the configuration of the seal or in particular of the second leg or the sealing surface is increased or only the contact pressure is increased. As a result, there is a particularly good sealing effect, especially with regard to leakage of a medium, if this is also required. As a result of the above-described mode of operation of the seal, it can also withstand significantly higher internal pressures compared with the solutions of the prior art.

In addition, the seal can be more resistant to diffusion due to the larger sealing thickness and sealing surface. In other words, the seal by the legs can absorb a higher pressure than comparable seals according to the prior art, whereby the sealing effect does not decrease with increasing pressure but the sealing effect just increases with increasing pressure.

A tightness to allow entry of undesirable substances into the housing can already be easily achieved by the first leg.

In summary, the above-described battery thus allows a cost-effective manner to realize a particularly well-defined and long-term stable sealing of a battery case in particular with respect to a contact bushing and, of course, further improved by the second leg.

As part of an embodiment, two second legs may be provided, each having different from each other one can be brought into contact with the first battery component or the second battery component in contact second sealing area. In other words, a first of the two second legs can have a sealing area that can be brought into contact with the first battery component, and a second of the two second legs can have a sealing area that can be brought into contact with the second battery component. The two legs can each have an opposite to the sealing region arranged or directed end region, which is connected to the first leg. In particular, in this embodiment, a particularly secure sealing effect can be caused. Because an enlargement of the sealing effect as a function of the pressure prevailing in the interior of the housing can be brought about on both battery components against which the seal bears, so that a complete two-stage seal comprising the first and the second legs is realized.

In the context of a further embodiment, the second leg may have a nominal deformation range. In particular, one or more or all of the existing second legs can have one and therefore exactly one or a plurality of predetermined deformation areas. For example, the desired deformation range can be formed by a targeted material change or material dilution and thus by a specific reduced stability of the second leg. Such structuring may in particular have the advantage that a particularly good sealing effect can be produced with a minimum possible amount of material. Because the areas of the desired deformation range need not cause a sealing effect below a predetermined pressure. However, this sealing effect can be easily caused when the internal pressure of the housing exceeds a predetermined value and the legs are deformed so as to abut a sealing system on a battery component. In addition, in particular a desired deformation point can ensure that even at a relatively low internal pressure, an enlarged sealing effect can be made possible. Because in the provision of a relatively thick leg, a large part of the energy applied by the pressure can be absorbed by the sealing material, which can usually be highly elastic, and thus be used only to a limited extent in order to increase the contact pressure. This effect can be circumvented by a defined nominal deformation range.

A prescribed nominal deformation range can be generated, for example, by a second leg having a wave profile on the side facing the first or the second battery component. If appropriate, one or both or all of the existing second legs may have a wave profile on the corresponding side. In this case, a wave profile may, in particular, be understood as meaning a structure which has, in particular, one or more, for example, rounded protrusions or one or more recesses. In particular, if such a wave structure is present only on one side on the opposite side of the attack surface, but the internal pressure facing side has no such structuring, the attack surface for the internal pressure can be particularly defined customizable and defined deformation positions or nominal deformation ranges can be generated.

In the context of a further embodiment, the seal may have a k-shaped cross-section. This embodiment can be particularly easy to produce and thereby be particularly effective. In particular, the two second legs can use a force acting from the interior of the housing particularly well to increase a contact pressure of the sealing system. In this case, a k-shaped cross section can be understood in particular as meaning a cross section in which the two second legs, or at least their engagement surfaces, extend essentially at an angle of 45 ° to the first leg. In this case, the orientation of the two second legs or their attack surfaces may differ from application by 45 °, insofar as they can use an increased internal pressure to increase the contact pressure of the respective sealing system and are aligned bevelled with respect to the orientation of the first leg.

Alternatively, the seal may have a U-shaped cross-section. For example, the two second legs or at least their engagement surfaces may together have a U-shaped cross-section and in particular be connected to the first leg in the bottom area of the U-shape. This embodiment can also produce a particularly effective sealing effect, since in particular a U-shaped engagement surface can be particularly advantageously suitable for converting an increased internal pressure into an increased contact pressure of the respective sealing systems located on the second legs.

In a further embodiment, the seal may be formed of a material selected from the group consisting of ethylene-propylene-diene rubber (EPDM), polytetrafluoroethylene (PTFE) or a thermoplastic elastomer (TPE). In particular, the abovementioned materials can be particularly suitable as sealing materials, since on the one hand they can produce a good sealing effect and can be particularly easily deformable depending on the exact configuration. In addition, the aforementioned materials are inert and stable, in particular to the conditions of a battery cell, so that a particularly good long-term stability is given.

In the context of a further embodiment, the first battery component may be a battery lid element and the second battery component may be a current collector. Thus, the seal may be arranged in this embodiment between the battery cover element and the current collector and seal a position located between these components position. In particular, in this embodiment, an effective sealing of the opening for performing the contact element can be realized because the contact element for electrical contact is often attached directly to the current collector and thus a seal directly to the attachment of the contact element feasible can be. Thus, a seal without the inclusion of other components can be realized, so that further unwanted leaks or leaks can be further reduced. In addition, in particular in this embodiment, a compact design can be realized.

With regard to further technical features and advantages of the battery according to the invention, reference is hereby explicitly made to the explanations in connection with the use according to the invention, the figures and the description of the figures.

The present invention is further a use of a seal for sealing the interior of a battery case against a contact hole for performing an electrical contact through the battery case, the seal having a first leg which extends from a first battery component to a second battery component and each having a the first and second battery components in contact having first sealing region, and wherein the seal further comprises a second leg having a first battery component or with the second battery component in contact engageable second sealing region, wherein the second leg through a in the interior of the Battery housing prevailing pressure is deformable such that the contact pressure of the sealing region of the second leg is increased to the first or the second battery component.

By using a seal described above for sealing a contact bushing in a battery, a particularly secure and long-term stable sealing effect can be made possible in a particularly cost-effective manner. In particular, it may be possible that at an elevated pressure, the sealing effect does not yield but increases, which has a high pressure resistance result. Likewise, bumps can be easily absorbed, as a larger area can be covered.

With regard to further technical features and advantages of the use according to the invention, reference is hereby explicitly made to the explanations in connection with the battery according to the invention, the figures and the description of the figures.

drawings

Further advantages and advantageous embodiments of the subject invention are illustrated by the drawings and explained in the following description. It should be noted that the drawings have only descriptive character and are not intended to limit the invention in any way. Show it

1 a schematic representation of a structure of a battery;

2 a sectional view of a portion of the battery 1 ;

3 a schematic representation of an embodiment of a seal for the battery 1 ;

4 a schematic representation of another embodiment of a seal for the battery 1 ; and

5 a schematic representation of another embodiment of a seal for the battery 1 ,

In 1 is a partial exemplary and non-limiting construction of a battery 10 shown. The battery 10 is in accordance with 1 in particular, a lithium ion secondary battery which has battery cells in a prismatic form. The battery cell therefore has in the embodiment according to 1 a winding element 12 in which a copper foil coated with anode material, an aluminum foil coated with cathode material and, for example, two plastic foils which serve as separators or diaphragms are laid over one another or wound and pressed flat. For electrical contacting the copper foil and the aluminum foil along the winding axis are inserted slightly offset in the opposite direction. Thus, the copper foil on one narrow side and the aluminum foil on the other narrow side over. The resulting projecting foil strips 14 serve for electrical contacting of anode or cathode. For the sake of clarity, only the protruding foil strips are used 14 a pole shown. In a manner understandable to the skilled person are for each pole, including on the foil strips 14 opposite side and adjacent to the opposite pole, also protruding foil strips 14 arranged to contact them as well.

The energy storage 10 according to 1 also has a safety device also called NSD (Nail Penetration Safety Device) 16 on. Further, a housing 18 for receiving the winding element 12 or the winding elements 12 provided on the outer side an electrical insulation 20 , such as a shrink tube, may have. In the case 18 is on the case back also an electrical insulation 22 intended. Furthermore, the housing 18 especially filled with a liquid electrolyte.

For electrical contact, the battery 10 Furthermore, two current collectors shown here only schematically 240 on. The current collectors 240 are each with a connecting bolt 26 as electrical contact for mechanically and electrically contacting the battery 10 electrically connected. Furthermore, each is an insulation 28 for the winding element 12 and one insulation each 30 for the current collectors 240 intended.

Furthermore, the housing 18 or a trough-like region of the same in an upper region at least partially, in particular completely by a cover such as having a cover plate 32 covered, between which and the current collectors 240 and in particular the connecting bolt 26 framing each arranged a seal 34 and a seal insulator 36 are provided. The seal 34 is in detail in the 2 to 4 described.

For example, in the case of an error, excessive pressure from the container 18 to be able to discharge is in the cover plate 32 also a rupture disk 38 intended. The battery 10 further includes a membrane, such as an OSD membrane 40 in the cover plate 32 is admitted. On the cover plate 32 can also arranged a cover plate insulating film 42 its what recesses 44 having. Inside the recesses 44 and arranged on the cover plate 32 in particular adjacent to the positions of the connecting bolts 26 are further provided a potential plate 46 and a top plate arranged thereon 48 which together with an insulation 50 on a connection plate 52 may be arranged, and further below the connecting plate 52 a distance insulator 54 like this from the 1 is apparent. Further, one is in the cover plate 32 let in plugs 56 provided, an opening 33 can close to the insertion of electrolyte.

In the 2 is an enlarged section of the battery 10 shown. Again shown are the current collector 240 at which the contact pin 26 is fixed, which through an opening of the housing 18 runs. Above the current collector 240 is the cover plate 32 as part of the housing 18 or housing cover shown, between which cover plate 32 and current collector 240 the seal 34 as shown in detail below, is shown purely schematically. Furthermore, an insulator 74 shown, which serves electrical insulation and also the top plate 48 .. In addition, the below the cover plate 32 arranged sealing ring insulator 36 shown.

In the 3 is a first embodiment of the seal 34 shown, with the seal 34 between the cover plate 32 as a battery cover element and the current collector 240 is arranged. The seal 34 has a first leg 60 on top of the cover plate 32 to the current collector 240 runs. The first leg 60 includes one each with the cover plate 32 or the current collector 240 in contact first sealing area 61 . 61 ' , Furthermore, the seal points 34 two second thighs 62 . 62 ' on. The second thighs 62 . 62 ' have one with the cover plate 32 or with the current collector 240 in contact second sealing area 63 . 63 ' on. The second thighs 62 . 62 ' are doing so by one inside the battery case 18 prevailing pressure deformable such that the contact pressure of the second leg 62 . 62 ' or the second sealing areas 63 . 63 ' to the cover plate 32 or to the current collector 240 is enlarged, as it should be symbolized by the arrows, which on a target surface 67 . 67 ' the seal 34 or the second leg 62 . 62 ' should represent acting pressure. In the embodiment according to 3 shows the seal 34 or have the two second legs 62 . 62 ' together on a U-shaped cross section.

In the 4 is another embodiment of a seal 34 shown. The seal 34 according to 4 points to the second thighs 62 . 62 ' Target deformation regions 65 . 65 ' on, which are formed in particular by a on the cover plate 32 or the current collector 240 facing side arranged wave profile.

In the 5 is another embodiment of a seal 34 shown. The seal 34 according to 5 also has two second legs 62 . 62 ' which are shaped so that the seal 34 has a k-shaped cross-section.

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 2010/0021811 A1 [0004]
• JP 2012-049076 [0005]

Claims (10)

Battery comprising a battery case ( 18 ), the battery case ( 18 ) has a contacting opening, wherein an electrical contact for tapping electrical energy from the battery ( 10 ), wherein the interior of the battery case ( 18 ) against the contacting opening by a seal arranged between a first and a second battery component ( 34 ), characterized in that the seal ( 34 ) a first leg ( 60 ) extending from the first battery component to the second battery component, and each having a first sealing region in contact with the first and second battery components (US Pat. 61 . 61 ' ), and wherein the seal ( 34 ) further comprises a second leg ( 62 . 62 ' ) having a second sealing area (FIG. 2) which can be brought into contact with the first battery component or with the second battery component (US Pat. 63 . 63 ' ), wherein the second leg ( 62 . 62 ' ) by a inside of the battery case ( 18 ) prevailing pressure is deformable such that the contact pressure of the second sealing area ( 63 . 63 ' ) is increased to the first or the second battery component. Battery according to claim 1, characterized in that two second legs ( 62 . 62 ' ) are provided, each of which different from each other one can be brought into contact with the first battery component or the second battery component in contact second sealing area ( 63 . 63 ' ) exhibit. Battery according to claim 1 or 2, characterized in that the second leg ( 62 . 62 ' ) a nominal deformation range ( 65 . 65 ' ) having. Battery according to claim 3, characterized in that the second leg ( 62 . 62 ' ) has a wave profile on the side facing the first or the second battery component. Battery according to one of claims 2 to 4, characterized in that the seal ( 34 ) has a k-shaped cross-section. Battery according to one of claims 2 to 4, characterized in that the seal ( 34 ) has a U-shaped cross-section. Battery according to one of claims 1 to 6, characterized in that the seal ( 34 ) is formed of a material selected from the group consisting of ethylene-propylene-diene rubber, polytetrafluoroethylene or a thermoplastic elastomer. Battery according to one of claims 1 to 7, characterized in that the first battery component is a battery cover element and that the second battery component is a current collector ( 240 ). Battery according to one of claims 1 to 8, characterized in that, the battery ( 10 ) is a lithium-ion battery. Using a gasket ( 34 ) for sealing the interior of a battery case ( 18 ) against a contacting opening for making an electrical contact through the battery housing ( 18 ), characterized in that the seal ( 34 ) a first leg ( 60 ) extending from a first battery component to a second battery component and each having a first sealing area in contact with the first and second battery components (US Pat. 61 . 61 ' ), and wherein the seal ( 34 ) further comprises a second leg ( 62 . 62 ' ) having a second sealing area (FIG. 2) which can be brought into contact with the first battery component or with the second battery component (US Pat. 63 . 63 ' ), wherein the second leg ( 62 . 62 ' ) by a inside of the battery case ( 18 ) prevailing pressure is deformable such that the contact pressure of the second sealing area ( 63 . 63 ' ) is increased to the first or the second battery component.

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