WO2013110359A1 - Battery and motor vehicle - Google Patents

Abstract

The invention relates to a battery (14), having a plurality of battery modules (12) that comprise a plurality of battery cells (10). The battery (14) also comprises a degassing system (15), which has a degassing line (16) having openings (17). The openings (17) fluidically connect the battery modules (12) to the degassing line (16). The battery is characterized in that a respective blocking element (26) is operatively connected to each opening (17) in such a way that the openings (17) allow flow into the degassing line (16) but are blocked in the opposite direction. The invention further relates to a motor vehicle comprising the battery (14) according to the invention.

Description

 description

title

 Battery and motor vehicle The present invention relates to a battery having a plurality of

 Battery modules comprising a plurality of battery cells. The battery further includes a degassing system having a degassing line with openings. The openings connect the battery modules

fluidically with the degassing line. Furthermore, the invention relates to a motor vehicle with the battery according to the invention.

State of the art

It is becoming apparent that in the future, both in stationary applications, such as wind turbines, in motor vehicles, which are designed as hybrid or electric motor vehicles, as well as electronic devices, such as laptops or mobile phones, new battery systems will be used, to the very high

Requirements with regard to reliability, safety, performance and service life.

FIG. 1 shows how a plurality of battery cells 10 can be combined to form a battery module 12 and subsequently a plurality of battery modules 12 to form a battery 14. This is done by a parallel or not shown

Series connection of the poles of the battery cells 10. The electrical voltage of a battery 14 is for example between 12 and 750 volts DC.

In vehicles with at least partial electric drive batteries are used to store the electrical energy for the electric motor which supports the drive or drive. In the vehicles of the latest generation, so-called lithium-ion batteries can be found here

Use. These are characterized among others by high energy densities and an extremely low self-discharge. Lithium-ion battery cells have at least one positive and one negative electrode (cathode or anode), the lithium-ion (Li +) reversible on (intercalation) or outsource

(Deintercalation) can.

Inside, a battery cell is made up of electrochemical elements that are sensitive to external influences such as air or moisture and therefore need to be protected as much as possible. Should a malfunction nevertheless occur (eg as a result of an accident or overcharging), an inadmissible gas formation may occur. With it one

Battery cell does not burst and subsequent damaged further battery cells, a safety opening 1 1 is arranged in the battery cell housing, for example in its lid - visible in Figure 1. At an increased internal pressure of the battery cell, the safety opening opens and the battery cell can degas.

However, the leakage of gases can cause damage to the battery as the gases may contain electrolyte. These degassing products can be corrosive with water. It is therefore necessary to remove the degassing products emerging from the battery cell in a targeted manner. These are the

Degassing degassed in a degassing system, which collects the escaping degassing and selectively dissipates. This degassing system is connected to all battery cells.

DE 10 2009 046 385 A1 describes a degassing system of a battery, wherein the battery cells comprise on their undersides outlet openings for battery gas and electrolyte. At an overpressure inside the battery cells, the battery gases and electrolytes are discharged into a reservoir below the battery cells. The reservoir is connected via a fitting, which may for example be a check valve connected to the environment. The check valve prevents z. B. penetration of moisture of the ambient air into the battery. Disclosure of the invention

According to the invention, a battery is provided with a plurality of battery modules, which comprise a plurality of battery cells. The battery further comprises a degassing system, which has a degassing line with

Has openings. The openings connect the battery modules

fluidically with the degassing line. Characteristically, a blocking element is operatively connected to each opening in such a way that the openings in the degassing line are permeable, but the openings in

Counter direction are locked.

The invention is based on the finding to provide a blocking element at the module level in order to prevent the entry of degassing products into uninvolved ones

To prevent battery modules. In the context of the invention, degassing products can essentially be a gas emerging from the battery cell and / or

Electrolyte can be understood. The fluidic connection of the battery modules with the degassing line and thus the connection of the battery cells with the degassing line is designed to be permeable only in the direction of the battery module or the battery cells starting in the degassing. As a result, battery cells within a battery module, as known from the prior art, can degas into the degassing line. However, the degassing products in the degassing line can no longer contribute to other, not involved in the degassing,

Battery modules and their battery cells arrive. This prevents battery cells that are outside of a degassing module, dirty or z. B. damaged by corrosive effects of the degassing.

The battery modules are fluidically through openings in the

Degassing line connected to this, so that during the degassing of

 Battery cells within the battery modules, the degassing of the battery cells can get into the degassing. This functionality is inventively enabled by blocking elements, which in

Acting connection with the openings stand. The blocking elements have a functionality which allows the degassing products of the battery cells to pass through the opening into the degassing line. simultaneously However, the degassing are prevented by the blocking element, proceed from the degassing via the openings to other, uninvolved in the degassing, battery modules and their battery cells. Advantageously, the blocking element should be designed already at low

Press within the battery modules a flow of

Degassing products through the opening from the battery module in the

To allow degassing line. At the same time, the blocking module should be designed, even at high pressures within the degassing, a flow of degassing through the opening of the

 To prevent degassing line in the battery module. Such a blocking element can be realized by various components.

The blocking element is designed, for example, as a reversibly opening blocking element. A reversibly opening blocking element designates a blocking element which is designed, after the first passage of

Deaerate degassing products in the degassing again in the opposite direction. Reversible opening blocking elements are in particular

Check valves. A check valve is a component that allows the flow of a fluid in only one direction. Such a check valve may preferably be a beak valve or a spring-loaded check valve.

Further preferably, the blocking element is an irreversibly opening

Blocking element. An irreversibly opening blocking element denotes a

Blocking element, which after the first passage of

Degassing products in the degassing line is permanently open in both directions. Preferably, the irreversibly opening barrier element is a membrane or rupture disk. Furthermore, the irreversibly opening blocking elements also have a different resistance with respect to the

Direction of acting pressure on (eggshell principle).

The blocking element should be at least several days against corrosive

Characteristics of be discharged from the battery cells degassing be functionally resistant. Stay the blocking elements despite influence of

Degassing products at least several days functional, consists in the Usually enough time to repair the damage before further

Battery cells are affected.

Particularly preferably, the blocking element is functionally resistant to corrosive properties of degassing products which can be discharged from the battery cells. Through the use of blocking elements, which remain functional despite the influence of degassing even for a long time, the check valves of not involved in the degassing battery modules must not be renewed or repaired.

Preferably, a blocking element per battery module is provided. The fact that only one blocking element and no further blocking elements are used per battery module, the number of components can be reduced without significant disadvantages, z. B. when a battery module is designed as the smallest unit to be replaced. A battery module preferably comprises more than two battery cells, furthermore preferably more than five battery cells, in particular preferably six battery cells. A battery preferably comprises more than two battery modules, furthermore preferably more than five battery modules.

As a rule, the battery cells comprise safety openings through which the battery cells can degas. The safety openings are preferably arranged on the side of the battery cells facing the poles. This is usually the top of the battery cells when installed, whereby the degassing of the electrolyte content in the degassing is relatively low.

According to a preferred embodiment of the invention that includes

Battery module a collector for collecting ventable from the battery cells degassing. The collector is used to collect degassing products, which emerge from the safety openings of the battery cells. The collector is fluidically, for example via a

Intermediate line and connected via the opening with the degassing line.

Preferably, the collector is integrated in a module housing cover. With this configuration, the module housing cover and the collector are one and the same component, whereby components can be saved and can be omitted in the production assembly steps. According to a preferred embodiment of the invention, the

Degassing line connections and connected to the connections

Hoses, wherein the openings are formed by the terminals.

For example, the degassing line may comprise a section which is realized by pieces of hose and alternately interposed T-ports. A branch of the T-connections leads to a battery module and connects it to the degassing line. In this branch can

for example, be arranged the blocking element.

Preferably, the battery is a lithium-ion battery comprising a plurality of lithium-ion battery cells (secondary cells). Lithium-ion battery cells are characterized by high energy and power densities, resulting in further advantages, especially in the field of electric traction.

Furthermore, a motor vehicle with the battery according to the invention is provided. The battery is usually for feeding an electric

Drive system of the vehicle provided.

Further, a degassing system for a battery having a plurality of battery modules comprising a plurality of battery cells is provided. The degassing system comprises a degassing line with openings, which are suitable, fluid modules with the battery modules

To connect degassing line. Characteristic feature of each opening in each case a blocking element operatively connected such that the openings in the

Degassing line are permeable, but the openings in

Counter direction are locked.

Advantageous developments of the invention are specified in the subclaims and described in the description.

drawings

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below. Show it: 1 shows a battery cell, a battery module and a battery,

Figure 2 is a schematic partial view of a battery according to the invention, Figure 3 is an interior view of a module housing cover comprising a

 Blocking element, and

Figure 4 is an exterior view of a module housing cover comprising a

Blocking element.

FIG. 1 has already been discussed to explain the state of the art.

Figure 2 shows a schematic partial view of a battery 14 according to the invention with a degassing system 15. The degassing system 15 forms a

Degassing line 16 with openings 17. The degassing line 16 can, for example, via connections 24 in the form of T-connections with

intermediate hoses 25 may be formed. In that arm of the

T terminals, which leads to a battery module 12 of the battery 14, a blocking element 26, for example, a check valve, may be arranged. The battery cells 10 of the battery module 12, for example, in a

 Battery module housing 19 may be arranged and encapsulated from the outside world, wherein the battery module housing 19 via the terminal 24 with the

Degassing line 16 is connected. Degassed one of the battery cells 10, so are their degassing, in

Substantial battery gas and / or electrolyte, within the

Battery module housing 19 collected and passed through the blocking element 26 through the opening 17 in the degassing 16. Via the degassing line 16, the degassing products from the battery 14 and from their

Battery case, for example, to the outside. On her way through the

 Degassing line 16, the degassing products are prevented by the blocking elements 26, to the battery cells 10 other, not degassing

Battery modules 12 penetrate. Thus it prevents the others

Battery modules 12 of the battery 14, which are not affected by the degassing of a battery cell 10, are damaged by the corrosive effect of the degassing products. Damage to non-degassing battery cells 10 im degassing battery module 12 can be tolerated if z. B. the

Battery module 12 is designed as the smallest unit to be replaced in the battery 14. The blocking element 26 should, at least for a certain time, for example several days, against the corrosive properties of the degassing of battery cells 10, z. As lithium-ion battery cells, be resistant. As a result, the remaining battery modules 12 remain protected until repair or replacement of the degassing battery module 12 and associated cleaning of the degassing system 15.

In addition, the blocking element 26 can be reclosed, that is to say reversibly opening, or else designed to be irreversibly opening. The reversible opening

Locking element 26 can be made of both flexible materials, eg. B. be executed in the form of a beak valve, or with a spring mechanism. Furthermore, the irreversibly opening blocking element 26 may be designed in the form of a membrane or rupture disk, in particular with different resistance with regard to the direction of the acting pressure (eggshell principle). The battery 14, or parallel connection of several battery cell strands of the affected strand, should not be used until replacement of the degassed battery cell 10 or the affected battery module 12 and a speedy repair is appropriate. Figure 3 shows the battery cells 10 facing inside a

Module housing cover 18 of a battery module 12. In the module housing cover 18, a collector 20 is integrated, which collects the escaping degassing of the battery cells 10 of the battery module 12. For this purpose, the collector 20 is arranged trough-shaped over the safety openings 1 1 of the battery cells 10. The collector 20 may also be framed by a groove 22, in which a seal can be inserted. The seal seals the transition between the collector 20 and the battery cells 10, so that the degassing products flowing from the safety openings 11 into the collector 20 can not contact the other areas of the battery cells 10, for example their poles. The degassing products are passed via the opening 17 from the collector 20 into the degassing line 16. FIG. 4 shows the outside of the already known from FIG

Module Housing Cover 18. Analogous to Figure 2, the terminal 24 is formed as a T-terminal, wherein a hose 25 can be connected to each of the two free ends of the T-terminal. At this

 Hoses 25 further connections 24 of other collectors 20 can be connected until all the collectors 20 of the degassing system 15 are connected to each other via the degassing line 16. In each port 24 of the collectors 20, a blocking element 26 is integrated. Now degas one or more battery cells 10, a battery module 12, the escaping

Degassing no longer via port 24 in adjacent

Collectors 20 and thus penetrate into the battery modules 12.

Claims

claims 1 . A battery (14) having a plurality of battery modules (12) comprising a plurality of battery cells (10), the battery (14) further comprising  Degassing system (15), comprising:  a degassing line (16) with openings (17), which connect the battery modules (12) fluidically with the degassing line (16), characterized in that  a blocking element (26) is operatively connected to each opening (17), such that the openings (17) in the degassing line (16) are permeable, but the openings (17) are blocked in the opposite direction. 2. Battery (14) according to claim 1, wherein the blocking element (26) a  Check valve is. 3. Battery (14) according to claim 2, wherein the check valve a  Beak valve or a spring-loaded check valve is. 4. Battery (14) according to claim 1, wherein the blocking element (26) is an irreversibly opening blocking element. 5. Battery (14) according to claim 4, wherein the irreversibly opening blocking element (26) is a membrane or a rupture disk. 6. Battery (14) according to one of the preceding claims, wherein the  Blocking element (26) against corrosive properties of the Battery cells (10) is functionally resistant to leaking degassing. 7. Battery (14) according to any one of the preceding claims, wherein each battery module (12) comprises a collector (20) for collecting from the battery cells (10) releasable degassing products. 8. Battery (14) according to claim 7, wherein the collector (20) in one  Module housing cover (18) is integrated. 9. Motor vehicle with the battery (14) according to one of the preceding claims.