WO2014001042A1

WO2014001042A1 - System for sealing off electrical connection poles of a rechargeable battery

Info

Publication number: WO2014001042A1
Application number: PCT/EP2013/061550
Authority: WO
Inventors: Oliver Gerundt; Mathias Zink; Andreas Eichendorf; Thomas Rahn; Markus Feigl
Original assignee: Robert Bosch Gmbh
Priority date: 2012-06-27
Filing date: 2013-06-05
Publication date: 2014-01-03
Also published as: DE102012210927A1

Abstract

The invention provides a system for sealing off electrical connection poles of a rechargeable battery, wherein the system comprises: a housing having at least one electrical storage element, wherein the housing has at least two passage openings for the connection poles which are electrically connected to the storage element; first sealing elements which are each arranged completely around a connection pole and between said connection pole and the corresponding passage opening; and second sealing elements which are each arranged within the housing over the entire circumference of a first sealing element and over a housing inner surface in a sealing manner.

Description

Description title

System for sealing electrical connection poles of a rechargeable battery

The present invention relates to a system for sealing electrical

Terminal poles of a rechargeable battery, in particular for sealing connection poles of a lithium-ion battery for use in the automotive sector.

State of the art

Lithium-ion batteries (hereinafter Lilon batteries for short) are known from the prior art, which are used in particular in the automotive sector. These Lilon batteries have a housing, mostly for spatial reasons in a prismatic form, in which there is an electrical storage element which stores electrical energy and on demand, for example in a hybrid vehicle for the power supply of drive motors, provides. However, a detailed description of the memory element should be omitted here, as this is known

is assumed.

Particular attention, however, must be given to the configuration of the current feedthroughs, or in the following also referred to as terminal poles, which form a passage through the housing. Here, the requirements on the one hand, that the respective implementation is sealed for a terminal pole so that the pressurized electrolyte located in the housing can not escape. On the other hand, the connecting poles must withstand mechanical stresses without endangering the tightness. The mechanical loads are in the

Essentially by lateral forces and bending moments.

From the prior art, for example DE 10 2010 022 584 A1, so-called seal gasket seals are known to fulfill the above-mentioned requirements (see further the description with reference to Figures 1 and 2), which both the function of Sealing and the electrical insulation of the terminal poles relative to the housing as well as the function of recording the mechanical Take over loads on the connecting poles. The problem is, however, that the material of this seal gasket seals relaxes, ie its dimensions over the life does not comply and thus it can lead to leaks in the terminal poles. In addition, the seal gaskets seal can be additionally deformed by the absorption of shear forces, and the seal does not self-healing (in the sense of the so-called "design rule of self-help"), ie elastic, to compensate for the resulting leaks again.

Disclosure of the invention

The invention proposes, in a first aspect according to claim 1, a system for sealing electrical connection poles of a rechargeable battery, the system comprising: a housing with an electrical storage element, wherein the housing has at least two through openings for terminal poles electrically connected to the storage element; first sealing elements, which in each case fully around a terminal pole and between this and the corresponding

Through openings are arranged; and second sealing elements, which are disposed within the housing completely on a circumference of a first sealing element and on a housing inner surface in a sealing manner.

Advantages of the invention

The advantage of the proposed system results from the fact that the functions are divided in terms of sealing and insulating and recording mechanical loads on different components or of different

Functional areas of a component are taken. Thus, it is ensured that, for example, an electrical insulation and a seal is present, even if the electrical insulation has no sealing property. At the same time, it is ensured that transverse forces can be absorbed without causing leaks in the area of a terminal pole.

Preferably, the first sealing elements are made of a material which is electrically insulating and can mechanically absorb a force transverse to a longitudinal axis of a terminal pole. This has the advantage that the first sealing elements can be made of a material which is substantially relatively stable to mechanical stresses, without at the same time also only a sealing To take over function. In principle, therefore, the first sealing elements are not elements with a purely sealing function, in order to avoid the leakage of electrolyte fluid in the terminal poles, but elements that "seal" the space between the terminal poles and the through holes, but mainly for receiving mechanical loads are formed on the terminal poles. For the sake of simplicity, these elements should also be considered as

Be referred to as "sealing elements".

Furthermore, it is preferred that the second sealing elements are made of a material, in particular an elastomeric material, which in a plastic manner

is permanently elastic. Thus, it is avoided that the second sealing elements lose their sealing effect over time due to changes in shape. In addition, the second sealing elements are thus able to compensate for short-term deformations occurring due to mechanical loads (so-called

Self-healing).

In addition, it is preferred that the second sealing elements have a top recess and a bottom recess in cross section along its circumference. By this particular design of the second sealing elements is a lip-like

Sealing form achieved, which is particularly effective in terms of the desired seal.

Advantageously, the second sealing elements are molded onto the first sealing elements in the manner of a two-component component in an integral manner. This simplifies the production of the system and the installation in a rechargeable battery.

Preferably, the first sealing elements along their circumference, which adjoins the second sealing elements, each have a collar which engages in a correspondingly shaped recess in the second sealing elements. This is advantageous because it provides a mechanical stability of the second sealing elements.

Moreover, it is still preferred that the accumulator is a lithium-ion accumulator for use in an automotive vehicle, which is a

Hydropower vehicle, an aircraft or spacecraft and / or a land vehicle can act. For this type of vehicles, the disclosed invention is particularly suitable Way, since the stress, for example, in terms of mechanical forces due to constant movements are relatively high.

Brief description of the drawings

The invention will be explained below with reference to embodiments in conjunction with the figures, in which:

Figure 1 shows a structure of a conventional lithium-ion battery in one

Exploded view shows;

Figure 2 shows a detailed view of a terminal pole of the battery of Figure 1;

Figure 3 shows a detail view of a terminal pole with a sealing system according to an embodiment of the invention; and

Figure 4 shows a detailed view of a terminal pole with a sealing system according to another embodiment of the invention. Embodiments of the invention

Figure 1 shows an essential schematic structure of a conventional lithium-ion battery 10 in an exploded view. Here, only the essential components are shown for better understanding. The battery 10 comprises a housing 15, in the interior of which a flat-pressed winding made of an aluminum foil and a copper foil is located (not shown here), the foils being coated in each case with active cathode and anode materials. For completeness, it should be mentioned that between the aluminum foil and copper foil, a separator, that is a plastic or

Ceramic foil, is arranged. The housing 15 is filled after introduction of the coil with a liquid electrolyte.

The electrical contacting of the cathode or anode foil of the roll takes place via electrical connections 20, of which the electrical connection shown in FIG. 1 on the right-hand side of the picture is outside the housing 15 for better illustration of the structure the power terminals 20, 21 is shown. However, since the basic structure of such power connections 20, 21 should be well known, and also contributes nothing to the core of the invention, will be omitted here for a further description. Of interest here is only that each power connection 20, 21 via one each

Terminal pole 25, 26 has, each of which through through holes 30, 31 in a housing closure plate 35 form a compound of the housing 15 located in the coil outwards. Furthermore, in the region of the connection poles 25, 26, so-called seal gaskets seals 40, 41 can be seen in FIG. 1, which will be described in detail below. These seals 40, 41 essentially form a seal between the

Terminal poles 25, 26 and the through holes 30, 31 of the

Housing closure plate 35 and one insulation plate 45, 46, which is respectively disposed below the housing closure plate 35, and which also each have a through hole 50, 51 for the connection poles 25, 26 have. Other openings, particularly those illustrated in the housing closure plate 35, are not relevant to the present disclosure and are therefore not considered here. FIG. 2 shows a detailed view of a connection pole 25, in this case a

Cross-sectional view of the terminal pole 25 shown in Figure 1 on the left side of the image. In addition to the terminal 25 is still a part of the housing closure plate 35, the housing 15, the insulating plate 45 and the seal 40, each in cross-section to recognize. Decisive here is the seal 40, which is usually made of a thermoplastic, for example Teflon, and, as mentioned above, must perform several functions, that is sealing the terminal pole 25 relative to the housing or the housing closure plate 35 against leakage of under pressure

standing, liquid electrolyte, and absorption or absorption of mechanical loads on the terminal pole (or on the terminal poles 25, 26), which are essentially transverse forces and bending moments. The latter function, that is to say the absorption of mechanical loads by the seal 40, is therefore crucial in order to prevent any leakage from occurring at the connection pole 25, that is, an escape of electrolyte fluid. As already mentioned above, the seal 40 must be able to fulfill all the requirements mentioned at the same time, but it is already due to a mechanical load of the Terminal pole 25 is relatively easy to come to a leak on the seal 40, and the material of the gasket 40 itself usually does not meet the requirements to compensate for a deformation of its own again, ie to "heal" itself. Figure 3 now shows a similar detail view of a terminal pole 25, but according to an embodiment of the present invention.

In the embodiment illustrated in FIG. 3, it is crucial that the seal 40 shown in FIG. 2 has been replaced by two elements, namely by a first sealing element 55 and a second sealing element 60. Thus, the functions previously known from seal 40 (see FIG 2) have now been split into two elements. The first sealing element 55 essentially serves to produce an electrical insulation between the connection pole 25 and the housing closure plate 35 and to absorb mechanical transverse forces on the connection pole 25, while the second sealing element 60 only performs the function of sealing, that is to prevent electrolyte fluid in the Area of the terminal 25 can escape from the housing 15.

In the embodiment shown in Figure 3, the first sealing member 55 and the second sealing element 60 are each made of different materials, the second sealing element 60 is permanently elastic designed to accommodate occurring deformations and the pending internal pressure in self-healing or.

Self-healing manner via a corresponding contact pressure of the sealing surfaces of the second sealing element 60 to the surrounding partner sealing surfaces, that is first sealing element 55, housing closure plate 35, and insulation plate 45 to compensate. This means that the tightness in the region of the connection pole 25 even after a long time

Operating time and guaranteed by mechanical deformation. Preferably, the second sealing element 60 is made of an elastomeric material. But any other suitable material or combination of materials is conceivable for the sealing elements.

As can be seen in Figure 3, the second sealing element 60 in cross-section the shape of the letter "H", in other words, the second sealing element 60 has along its circumference an upper recess 61 and a lower recess 62, so that for sealing advantageously two upper lips 63 and two lower lips 64 result. FIG. 4 shows a further embodiment of the present invention, wherein the difference from the embodiment shown in FIG. 3 is that the first sealing element 55 has on its circumference a collar 70, which in one

correspondingly shaped recess 80 in the second sealing element 60 engages. The collar 70, which engages in the recess 80 in the second sealing element 60, serves to mechanically stabilize the second sealing element 60 and, as in the embodiment shown in FIG. 3, may be designed in the manner of a two-component component, the second sealing element 60 in FIG integral manner to the first sealing element 55 and the collar 70 may be molded. Of course, other suitable types of connection of the first sealing element 55 with second

Sealing element 60 conceivable. It should also be mentioned that the above with respect to the sealing elements refers to both terminal poles in the same way.

In summary, it can therefore be said that the present invention is distinguished by the fact that the functions of sealing, isolating and absorbing transverse forces are either divided into two components, namely the first sealing element and the second sealing element, or are taken over by different functional regions of an assembly, in the case an integral version of the two sealing elements. Finally, it should be noted that the dimensions shown in Figures 1 -4 are not true to scale.

Claims

claims

1 . System for sealing electrical connection poles (25, 26) of a

Accumulator (10), comprising: a housing (15) with at least one electrical storage element, wherein the housing (15) has at least two through openings (30, 31) for the connection poles (25, 26) electrically connected to the storage element; first sealing elements (55), which are arranged in each case completely around a connection pole (25, 26) around and between this and the corresponding passage opening (30, 31); and second sealing members (60) which are disposed within the housing (15) completely circumferentially on a circumference of a first sealing member (55) and on a housing inner surface of the housing (15) in a sealing manner.

2. The system of claim 1, wherein the first sealing elements (55) are made of a material which is electrically insulating and is designed such that it occurs when a mechanical force transversely to a longitudinal axis of a

Terminal pole (25, 26) absorbs them.

3. System according to claim 1 or 2, wherein the second sealing elements (60) are made of a material which is permanently elastic in a plastic manner and is preferably an elastomeric material.

4. System according to any one of the preceding claims, wherein the second

Have sealing elements (60) in cross-section along its circumference an upper recess (63) and a lower recess (62). System according to one of the preceding claims, wherein the second

Sealing elements (60) are integrally molded onto the first sealing elements (55) in the manner of a two-component component.

System according to one of the preceding claims, wherein the first

Sealing elements (55) along their circumference, which adjoins the second sealing elements (60), each having a collar (70) which engages in a correspondingly shaped recess (80) in the second sealing elements (60).

A system according to any one of the preceding claims, wherein the accumulator (10) is a lithium-ion accumulator for use in an automotive vehicle.