WO2013091916A1

WO2013091916A1 - Sealing apparatus for sealing a lithium-ion rechargeable battery and lithium-ion rechargeable battery

Info

Publication number: WO2013091916A1
Application number: PCT/EP2012/068481
Authority: WO
Inventors: Oliver Gerundt; Mathias Zink; Thomas Rahn; Andreas Eichendorf; Markus Feigl
Original assignee: Robert Bosch Gmbh
Priority date: 2011-12-20
Filing date: 2012-09-20
Publication date: 2013-06-27
Also published as: DE102011089138A1

Abstract

The invention provides a sealing apparatus (15) for sealing a lithium-ion rechargeable battery (1), wherein the sealing apparatus (15) is designed to electrically insulate and seal, in fluid-tight fashion, a current collector connection (10) which is guided through a housing wall of a housing (2) of the lithium-ion rechargeable battery (1) with respect to the housing (2), wherein the sealing apparatus (15) has an insulating device (16) for electrically insulating the current collector connection (10) with respect to the housing (2) and a sealing device (20) formed separately from the insulating device (16) for sealing, in fluid-tight fashion, the current collector connection (10) with respect to the housing (2). The invention also provides a lithium-ion rechargeable battery (1) with a housing (2); with a current collector connection (10) which is guided through a housing wall of the housing (2); and with a sealing apparatus (15) for sealing the lithium-ion rechargeable battery (1), wherein the sealing apparatus (15) is designed to electrically insulate and seal, in fluid-tight fashion, the current collector connection (10) with respect to the housing (2), and wherein the sealing apparatus (15) has an insulating device (16) for electrically insulating the current collector connection (10) with respect to the housing (2) and a sealing device (20) formed separately from the insulating device (16) for sealing, in fluid-tight fashion, the current collector connection (10) with respect to the housing (2).

Description

Description title

Sealing device for sealing a lithium-ion accumulator and lithium-ion accumulator

The invention relates to a sealing device for sealing a lithium-ion battery and a lithium-ion battery with such a sealing device.

State of the art

In the automotive sector, in particular in so-called hybrid vehicles, lithium ion accumulators are often used because of their high energy density. Such a lithium-ion battery is described for example in DE 600 03 862 T. A current collector terminal connected to a collector plate of the lithium ion secondary battery is led out of the housing of the lithium ion secondary battery. The task of sealing and insulating the current collector terminal relative to the housing and the transmission of acting on the current collector terminal transverse forces on the housing is taken over by a seal, a so-called seal gasket. However, this seal gasket can not guarantee the function of sealing over a lifetime of the lithium-ion accumulator, since the transmission of the transverse forces additionally stresses the seal gasket mechanically. Disclosure of the invention

The present invention according to claim 1 provides a sealing device for sealing a lithium-ion secondary battery, wherein the sealing device is adapted to electrically isolate and fluid-tight seal a current collector terminal passed through a housing wall of a housing of the lithium-ion secondary battery with respect to the housing the sealing device for electrically insulating the

Current collector terminal relative to the housing has an insulating device and for fluid-tight sealing of the current collector terminal relative to the housing a separately formed from the insulating sealing means. The present invention further provides a lithium-ion secondary battery having a

Casing; with a guided through a housing wall of the housing

Current collector terminal; and a sealing device for sealing the lithium ion secondary battery, wherein the sealing device is configured to electrically insulate and fluid tightly seal the current collector terminal opposite the housing, and wherein the sealing device for electrically isolating the current collector terminal from the housing comprises insulating means and fluid tight sealing of

Current collector terminal relative to the housing has a separately formed from the insulating sealing means.

Advantages of the invention

The idea of the invention according to claim 1 lies in the functions of insulating and sealing the lithium-ion secondary battery to two separate components, the

Isolation device and the sealing device to divide. This ensures that the sealing device only takes over the function of sealing and undergoes no mechanical stress. This arrangement of the invention ensures the tightness of the lithium-ion battery over its entire life. Further developments and variations of the invention are specified in the dependent claims.

According to one embodiment of the invention, the insulating device is designed to transmit transverse forces acting on the current collector connection to the housing. According to one embodiment of the invention, the sealing device is designed as an O-ring, K-ring or X-ring.

According to one embodiment of the invention, the insulating device has a first, in particular impact-resistant, material and the sealing device has a second, in particular elastic, element which differs from the first material of the insulating device.

Material on.

According to one embodiment of the invention, the sealing device is designed as a two-component injection molded part, wherein the sealing device is injection-molded in an injection molding process to the insulating device or wherein the insulating device in a

Injection molding is injection molded onto the sealing device. According to one embodiment of the invention, the insulating device essentially has a hollow cylindrical shape, wherein the insulating device encloses the current collector connection at least in sections circumferentially.

According to one embodiment of the invention, the sealing device is designed to expand under a housing internal pressure of the lithium-ion battery.

According to one embodiment of the invention, the current collector terminal is designed as a substantially cylindrical one penetrating a cover plate of the housing

Formed connecting element, which is electrically connected to a current collector of the lithium-ion battery.

According to one embodiment of the invention, the sealing device between the

Cover plate and the current collector arranged.

Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying drawings.

Brief description of the figures of the drawings

Show it:

Figure 1 shows schematically a side view of a lithium-ion secondary battery according to a preferred embodiment of the present invention;

FIG. 2 schematically shows a partial sectional view of a preferred embodiment of the invention

Lithium-ion accumulator according to the figure 1; and

Figure 3 shows schematically a partial sectional view of an alternative but also preferred

Embodiment of the lithium-ion battery according to FIG. 1

Embodiments of the invention FIG. 1 illustrates a preferred embodiment of a lithium-ion rechargeable battery 1 in a side view. FIGS. 2 and 3 illustrate in detail sectional views preferred embodiments of the lithium ion accumulator 1 according to FIG. 1. The lithium-ion accumulator 1 according to the preferred embodiment of FIG. 2 preferably has a fluid-tight housing 2. The housing 2 preferably has an approximately cuboid housing body 3, which is open in particular on a cuboid surface. The housing 2 may alternatively have a can, cylinder, tub shape or the like. The housing body 3 is preferably by means of a cover plate 4 of the

Housing 2 sealed fluid-tight. The housing body 3 and the cover plate 4 preferably have an aluminum alloy and are in particular welded together. The housing encloses a preferably electrolyte-filled interior 5 of the housing 2.

In particular, a flat-pressed winding is arranged in the inner space 5, which is rolled, for example, from an aluminum foil, a copper foil, which are each coated with the reactive cathode and anode materials, and two plastic foils serving as diaphragms. The housing 2 is filled after the introduction of the coil and before the pressure-tight closure with a liquid electrolyte. An electrical contact of the cathode or anode foil of the coil is preferably done on arranged on respective narrow sides of the films current collectors 6. Preferably, the

Lithium-ion battery 1 two current collectors 6 on. The current collectors 6 are designed, for example, as strip-shaped sheet-metal parts of copper and / or aluminum which are welded onto projecting foil sections of the cathode or anode foil. In the following, only one current collector 6 is discussed for the sake of simplicity.

The current collector 6 preferably has approximately an inverted L-shape, with a short leg 7 of the current collector 6 approximately parallel to the cover plate 4 of the

Housing 2 is arranged and a long leg 8 parallel and adjacent to the housing body 3 of the cover plate 4 away in the interior 5 extends. The long leg 8 is preferably connected to the cathode or anode foil of the lithium-ion

Accumulator 1 electrically conductively connected. The cover plate 4 is preferably fluid-tight, in particular gas-tight, with the housing body 3 operatively connected. Between the cover plate 4 and the current collector 6, in particular the short leg 7 of the

Current collector 6 is preferably a so-called lower insulator 9 is arranged. The lower insulator 9 is designed to keep the current collector 6 at a distance from the housing 2, in particular from the cover plate 4, to keep. The lower insulator 9 is formed, for example, with an insulating plastic material.

A, in particular bolt-shaped, current collector connection 10 is preferably guided through a housing wall of the housing 2, in particular through the cover plate 4. For this purpose, the cover plate 4, for example, a breakthrough 1 1. The current collector connection 10 is preferably designed as a substantially cylindrical connection element 10. In particular, the current collector connection 10 is electrically conductively connected to the current collector 6 of the lithium-ion accumulator 1. In particular, the

Current collector terminal 10 may be integrally formed with the current collector 6. Alternatively, the current collector terminal 10 may be soldered, welded, bolted, caulked or riveted to the current collector 6. In essence, the current collector terminal 10 is cylindrical, with a at least partially protruding from the housing 2 in the surrounding area 12 cylindrical terminal portion 13 and an operatively connected to the short leg 7 of the current collector 6 disc-shaped

Connecting section 14.

The lithium-ion accumulator 1 preferably has a sealing device 15, which is designed in particular to pass through the housing wall of the housing 2,

in particular guided by the cover plate 4, the lithium-ion battery 1

Current collector terminal 10 relative to the housing 2 to seal fluid-tight and in particular gas-tight. The sealing device 15 is preferably further adapted to the

Current collector terminal 10 to be electrically insulated from the housing 2 and to transfer acting on the current collector terminal 10 transverse forces on the housing 2. FIG. 2 illustrates by way of example a force F, which acts as a transverse force on the current collector connection 10.

The sealing device 15 has in particular a first material having insulating means 16 which is adapted to electrically isolate the current collector terminal 10 when passing through the housing wall of the housing 2 with respect to the housing 2. Furthermore, the insulating device 16 is designed to transmit the transverse force F to the housing 2, in particular to the cover plate 4. The insulating device 16 is formed, for example, with an impact-resistant plastic material, in particular a duroplastic. In particular, the insulating device 16 has a substantially stepped hollow cylindrical shape, which is tuned to an outer geometry of the current collector terminal 10. Preferably, the insulating device 16 encloses the Current collector terminal 10 at least partially circumferentially. The insulating device 16 may include a hollow-cylindrical first section 17 enclosing the connection section 13 of the current collector connection 10 and one, the

Connecting portion 14 of the current collector terminal 10 circumferentially enclosing, hollow cylindrical second portion 18 have. The sections 17, 18 are

preferably connected to each other by means of an annular intermediate portion 19. The intermediate section 19 preferably rests against the cover plate 4 from the interior 5. The first section 17 is preferably arranged circumferentially between the opening 11 of the cover plate 4 and the current collector terminal 10. The second section 18 is provided in particular between the current collector 6 and the cover plate 4.

Preferably, the second portion 18 has a larger inner and outer diameter than the first portion 17. The insulating device 16 is preferably formed as insulating bushing 16 and is disposed substantially between the current collector terminal 10 and the cover plate 4. Preferably, the lower insulator 9 surrounds the second portion 18 of the insulating device 16 at least partially circumferentially.

The sealing device 15 preferably has a sealing device 20 formed separately from the insulating device 16. The sealing device 20 has, in particular, a second material which differs from the first material of the insulating device 16. The second material has in particular a higher flexibility and / or elasticity than the first material. The sealing device 20 is preferably arranged between the current collector 6 and the cover plate 4. In particular, the sealing device 20 circumferentially surrounds the second section 18 of the insulating device 16. The sealing device 20 is preferably formed with an elastic material, such as a rubber, silicone and / or polyurethane material. The sealing device 20 is preferably arranged in a recess 21 of the lower insulator 9, in which preferably also the second portion 18 of the current collector terminal 10 is arranged. The sealing device 20 is suitable for sealing the current collector 6 or the current collector connection 10 in a fluid-tight manner and, in particular, in a gastight manner with respect to the cover plate 4. Preferably, the sealing device 20 is formed as an O-ring 20. When mounting the lithium-ion

Accumulator 1, a cross section of the O-ring 20 is preferably compressed by a predetermined percentage, for example by 10%, in order to ensure a reliable seal. The sealing device 20 may be operatively connected to the insulating device 16. For example, the sealing device 20 may be glued to the insulating device 16. Alternatively, the sealing device 20 may be formed as a so-called X-ring or as a so-called K-ring. Such an X-ring or K-ring has in cross section in each case approximately in an X or a K-shape. The use of an X-ring or a K-ring has the advantage that it expands at a prevailing in the interior 5 of the lithium-ion battery 1 housing internal pressure and thus the current collector 6 and the current collector terminal 10 reliably against the cover plate. 4 seals.

FIG. 3 illustrates a further preferred embodiment of a sealing device 15. In the following, only the differences between the sealing device 15 according to FIG. 3 and the sealing device 15 according to FIG. 2 will be discussed.

The sealing device 20 is preferably formed as a K-ring 20 in this alternative but also preferred embodiment of the sealing device 15. Alternatively, the

Sealing device 15 may be formed as an X-ring or as an O-ring. The sealing device 15 is preferably as a so-called two-component component 15, in particular as

Two-component injection molded part 15, formed. That is, the sealing device 20 is indeed formed as a separate component of the insulating device 16, but with this fixed, in particular cohesively, operatively connected. The insulating device 16 has the first material and the sealing device 20 has the first material

distinctive second material. For example, in an injection molding tool, the sealing device 20 can be injection-molded onto the insulating device 16 or the

Insulating device 16 can be molded onto the sealing device 20. Preferably, the sealing device 20 is molded onto the insulating device 16. Due to the design of the sealing device 15 as a two-component component 15, a particularly comfortable and easy installation of the sealing device 15 and thus of the lithium-ion battery 1 can be ensured.

In the figures, like reference numerals designate like or functionally identical components, elements and features, unless stated to the contrary.

Claims

Claims 1. Sealing device (15) for sealing a lithium-ion accumulator (1), wherein the sealing device (15) is adapted to a current collector terminal (10) guided through a housing wall of a housing (2) of the lithium-ion accumulator (1) the housing (2) to be electrically insulated and sealed fluid-tight,

characterized in that

the sealing device (15) for electrically insulating the current collector terminal (10) relative to the housing (2) an insulating device (16) and for fluid - tight sealing of the current collector terminal (10) relative to the housing (2) separately from the

Having insulating means (16) formed sealing means (20).

2. Sealing device according to claim 1, wherein the insulating device (16) is adapted to transmit to the current collector terminal (10) acting transverse forces (F) on the housing (2).

3. Sealing device according to claim 1 or 2, wherein the sealing device (20) is designed as an O-ring, K-ring or as an X-ring.

4. Sealing device according to one of the preceding claims, wherein the

Insulating device (16) a first, in particular impact-resistant, and the material

Sealing device (20) has a, of the first material of the insulating device (16) different, second, in particular elastic, material.

5. Sealing device according to one of the preceding claims, wherein the

Sealing device (15) is designed as a two-component injection-molded part (15), wherein the sealing device (20) is injection-molded on the insulating device (16) or wherein the insulating device (16) in an injection molding process to the

Sealing device (20) is molded.

6. Sealing device according to one of the preceding claims, wherein the insulating means (16) has a substantially hollow cylindrical shape, and wherein the insulating means (16) surrounding the current collector terminal (10) at least partially circumferentially.

7. Sealing device according to one of the preceding claims, wherein the

Sealing device (20) is designed to expand under a housing internal pressure of the lithium-ion battery (1).

8. Lithium ion accumulator (1)

with a housing (2);

with a through a housing wall of the housing (2) guided current collector terminal (10); and

with a sealing device (15) for sealing the lithium-ion accumulator (1), the sealing device (15) being designed to electrically insulate and fluid-tightly seal the current collector terminal (10) with respect to the housing (2),

characterized,

that the sealing device (15) for electrically insulating the current collector terminal (10) relative to the housing (2) an insulating device (16) and for fluid-tight sealing of the current collector terminal (10) relative to the housing (2) a separately formed from the insulating device (16) sealing means (20).

9. Lithium-ion secondary battery according to claim 8, wherein the current collector terminal (10) as a cover plate (4) of the housing (2) penetrating, substantially cylindrical connecting element (10) is formed, which with a current collector (6) of the lithium Ion accumulator (1) is electrically connected.

10. Lithium-ion accumulator according to claim 8 or 9, wherein the sealing means (20) between the cover plate (4) and the current collector (6) is arranged.