DE102012218968A1 - Battery housing for a battery cell with discharge opening and battery with battery housing and motor vehicle with battery - Google Patents

Abstract

The invention relates to a battery housing (1) for receiving at least one battery cell for a motor vehicle, a battery having a battery housing (1) and a motor vehicle with a battery providing drive energy. In order to be able to easily remove condensed water from the battery housing (1), the invention provides that the battery housing (1) is equipped with an outflow opening (8) pointing in a horizontal direction.

Description

The present invention relates to a battery housing having an internal volume for receiving at least one battery cell and having a floor for a motor vehicle. Furthermore, the present invention relates to a battery having an inner volume enclosing and a bottom battery housing and having at least one arranged in the inner volume battery cell. Furthermore, the present invention relates to a motor vehicle with a drive power for a drive device of the motor vehicle battery providing.

State of the art

Batteries having a battery case and at least one battery cell arranged in the battery case are widely used for the mobile use of battery powered devices. An example of such a device is a motor vehicle which can be driven at least partially or completely by the battery energy, in particular an automobile. The maximum electric power that can be supplied by the battery may have a voltage of up to 450 V or more at a current of, for example, 100 A or more. If a high electrical power is retrieved from the battery, it may heat up. As a result of the heating, the temperature of the battery can rise to such an extent that it leaves a predetermined operating temperature range. Outside the specified operating temperature range, the capacity and / or the life of the battery decreases. Even high ambient temperatures, for example of 60 ° C or more, can affect the life of the battery. Such high ambient temperatures often occur in motor vehicles, for example when they are standing or driving in the sun.

In particular, in order not to impair the service life of the battery due to excessive battery temperatures, the battery cells used are actively cooled, at least during operation of the device to be supplied with battery energy.

Within the battery case is often air, which surrounds the battery cell at least partially. In order to be able to adapt the internal pressure in the battery housing of the battery to the external pressure, the battery housing often has a pressure compensation element with which the battery housing can be ventilated. Consequently, during operation of the battery ambient air penetrates into the battery case. With the ambient air is water, z. B. in the form of steam, registered in the battery case. If the ambient air is cooled in the battery housing, the steam condenses out. Moisture can penetrate the housing even without air. For example, many battery cooling systems use a water-containing cooling fluid. If the cooling system is leaking, the cooling fluid containing water may enter the housing. However, liquid water within the battery case may affect the operability of the battery or battery cell due to corrosion or short circuit.

Disclosure of the invention

According to the invention, a battery housing is provided for receiving at least one battery cell which is provided with an outflow opening, wherein the outflow opening is fluid-conductively connected to a section of the inner volume adjoining the floor and aligned substantially opening transversely to the floor. Further, according to the invention, a battery is provided with a battery housing designed according to the invention. Furthermore, a motor vehicle is provided with a battery according to the invention.

Characterized in that the outflow fluid is fluidly connected to the adjacent to the bottom portion of the inner volume, located on the ground condensation can flow readily to and from the outflow opening from the battery case. Consequently, the operation of the at least one battery cell arranged in the battery housing is no longer impaired by condensed water accumulating in the battery housing since the condensed water can flow off via the outflow opening.

The solution according to the invention can be further improved by various configurations which are advantageous in each case and can be combined with one another as desired. These embodiments and the advantages associated with them will be discussed below.

Thus, the battery housing may have a drain opening adjoining the floor, which is connected by a drainage line to the outflow opening. With the drainage opening adjacent to the floor, smaller amounts of condensed water collected on the floor can also flow into the drainage opening and from there through the drainage line to the drainage opening. Through the drainage line, the outflow opening can be arranged at a distance from the bottom of the battery housing, so that the condensed water can be dispensed at a distance to the bottom of the battery housing without, for example, moistening the battery housing from the outside.

A drainage of condensed water and in particular smaller amounts of condensation is thereby made possible that the drain opening is preferably arranged in the ground or extends through the bottom and opens into the inner volume of the battery case. The drain opening can be arranged at the lowest point of the battery housing.

According to a further advantageous embodiment, the outflow opening can be arranged at a distance from the floor and in particular below the floor. The arrangement of the outflow opening in combination with the effect of gravity, the outflowing condensation is prevented from flowing back into the battery case.

The outflow opening is designed, for example, as a first opening and the outflow opening as a second opening of the drainage line, wherein the first and the second opening point in different directions.

The first and the second opening of the drainage line are preferably provided at different and in particular along the drainage line opposite arranged ends of the drainage line.

In particular, the drain opening can open parallel to the bottom of the battery case or vertically. The discharge opening therefore opens substantially perpendicularly to the discharge opening which opens transversely to the bottom, that is to say, for example, substantially horizontally.

From the discharge opening to the outflow opening, a drainage path runs through the drainage line. The drainage path extends in a direction parallel to the drainage drainage direction, wherein the drainage direction can change in the course of the drainage line.

In particular, the drainage line in the direction of drainage behind the drain opening vertically, so for example perpendicular to the ground, extend. Contrary to the direction of drainage behind the outflow opening, the drainage line can extend substantially horizontally, ie for example parallel to the floor. The drainage line has, for example, two line sections, one of which is adjacent to the drainage opening and at least partially aligned vertically. The other of the two line sections extends at least partially horizontally, ends in the outflow opening and connects these fluid conductively with the first line section.

In order to prevent water from entering the battery housing through the discharge opening arranged below the floor, a liquid barrier may be provided which is designed to prevent any liquid from flowing out of the discharge opening in the direction of the discharge opening. The liquid barrier is arranged, for example, at least partially in the drainage line and in particular designed to allow liquid to pass from the drainage opening to the outflow opening. For example, the liquid barrier is designed as a valve, in particular as a check valve.

For sealing the drainage line from outside of the battery case through the outflow opening into the battery housing or in the drainage line penetrating liquid, the liquid barrier may be provided with a circumferential sealing lip and provided in the drainage line sealing element. The sealing lip is preferably sealingly against an inner side of the drainage line. If the drainage line is designed with a round cross section, the sealing element or its sealing lip can also have such a shape. The sealing element is preferably formed in its state inserted into the drainage line substantially complementary to the inner cross section of the drainage line.

In order to prevent water from flowing into the battery housing in the opposite direction to the direction of drainage, a free end of the sealing lip of the sealing element inserted into the drainage line can be directed in the direction of drainage and, for example, on the outflow opening.

To make the liquid barrier easy to install without obstructing the drainage of liquid, the liquid barrier may be attached to an outside of the drainage line. For example, if a fastener of the liquid barrier and the drainage pipe allow it, the liquid barrier may be welded to the drainage pipe.

If the battery housing is arranged in a motor vehicle, then at least the outflow opening can be arranged outside the motor vehicle, so that condensation water from the battery housing can not flow into the motor vehicle but, for example, onto the roadway below the motor vehicle.

In a further advantageous embodiment, the outflow opening may open against a forward direction of the motor vehicle or point counter to the forward direction. The section of the drainage line which opens in the form of the outflow opening can extend substantially horizontally from the section of the drainage line running parallel to the floor, counter to the forward direction.

The drainage line may for example have an inner diameter of, for example, 10 mm, preferably 5 mm.

If the vehicle drives forward, air flows past the outflow opening. If the air flows past in the direction in which the discharge opening opens, the air flow generates a dynamic negative pressure, through which the condensed water is drawn through the discharge opening. The faster the vehicle drives, the faster the air flows past the outflow opening and the higher the negative pressure.

Even if the liquid barrier hinders drainage of the condensed water out of the outflow opening, the negative pressure at a certain speed of the air flow at the outflow opening can thus be sufficient to suck the water past the liquid barrier out of the battery housing.

Since the outflow opening is located at a distance from the bottom of the battery housing and, for example, between the motor vehicle and the road, the air can effectively flow along the outflow opening and thus generate the negative pressure without other components obstructing a flow of the air and swirling the air flow so strongly, for example. that no negative pressure arises anymore. The arrangement of the outflow opening is made possible by the drainage line which extends first vertically and then horizontally from the drainage opening to the outflow opening along the direction of drainage.

If the motor vehicle travels through water located on the roadway, for example through a puddle, the liquid barrier effectively prevents ingress of water, for example sprayed water, into the battery housing, even at high speeds.

In order to prevent freezing water in the drainage pipe at low temperatures and blocking it, the drainage pipe can be designed to be heatable. However, if the drainage line is heatable with battery energy, the battery energy available to other consumers will decrease. Consequently, the drainage line is preferably designed to prevent freezing of water within the drainage line without additional heating. In order to prevent water from freezing within the drainage line, the drainage line may have in its interior and / or on an outer wall a hydrophobic, in particular a superhydrophobic, coating which prevents liquid water or dirt particles from depositing on the inner wall of the drainage line and freeze there.

In particular, when using the battery housing according to the invention with a motor vehicle condensed water is efficiently removed from the battery case. However, the battery housing can also be used with other mobile devices, when the outflow opening according to the invention when using the battery housing is oriented transversely to the bottom of the battery case and / or horizontally opening. The battery case may also be used stationary when in use a wind blows and the discharge opening opens in the wind direction. For example, the battery case can be used with a wind turbine. In particular, in offshore wind turbines is to be expected that a constant wind or at least frequent wind blows along the outflow opening and generates the negative pressure. Since the wind can rotate during stationary use of the battery housing, the outflow opening can be designed to be movable. In particular, the drainage line may be rotatably connected to the bottom of the battery case.

The at least one battery cell is preferably a lithium-based battery cell and preferably a lithium-ion battery cell.

drawings

The invention is explained below by way of example with reference to embodiments with reference to the drawings. The different features of the embodiments can be combined independently of each other, as has already been explained in the individual advantageous embodiments.

Show it:

1 a schematic view of a battery case for receiving at least one battery cell; and

2 an enlarged view of a drainage line of the battery case.

Embodiments of the invention

First, the construction and function of a battery housing shown in greatly simplified form for receiving at least one battery cell with respect to the embodiment of 1 described.

The battery case 1 is in the 1 only roughly schematically illustrated in a sectional view and has a bottom 2 as well as the ground 2 opposite lid 3 and two the ground 2 with the lid 3 connecting side walls 4 . 5 on. A front wall and a rear wall, the also the ground 2 with the lid 3 connect are in the 1 not shown. Above the ground 2 and especially between the ground 2 and the lid 3 as well as between the side walls 4 . 5 is an inner volume 6 in the battery case 1 arranged. In the inner volume 6 can at least one, in the 1 however, not shown, be arranged battery cell. The at least one battery cell may be connected to the battery case 1 form a battery model or a battery for a motor vehicle. In particular, the battery module or the battery can provide drive energy for an at least partially or completely electrically drivable motor vehicle. The battery cell is preferably based on lithium and is in particular a lithium-ion battery cell.

The battery case 1 is with a pressure compensation element 7 provided by the gas and in particular ambient air in the battery case 1 can be directed. Optionally, gas can also be removed from the battery case 1 through the pressure compensation element 7 exit from the battery case when in the battery case 1 For example, an overpressure prevails. The pressure compensation element 7 is preferably formed, liquid water and solid suspended matter, such as dust, from entering the battery case 1 to prevent. Moisture contained in the ambient air may cause the pressure compensation element 7 However, do not prevent the air in the battery case 1 or in its inner volume 6 penetrate.

Penetrates moist air into the inner volume 6 of the battery case 1 On, so can the humidity when the temperature in the inner volume drops 6 condense. Will the condensation not escape from the battery case 1 Conducted, it may lead to corrosion, for example, terminal contacts of the battery cell or short circuits between the terminals. This would jeopardize the operability of the battery cell. The condensed water collects over time and due to gravity on the ground 2 ,

The condensation that has accumulated in the worst case on the battery pack bottom, can be contaminated by lying around in the battery pack small particles. If the insulation of at least two cell casings has been injured by these partly sharp-edged particles or, for example, during cell assembly, the conductive condensation water can lead to side or short circuits between the cell casings. Therefore, it is particularly advantageous to remove the condensation as quickly as possible from the battery case.

To get the water out of the battery case 1 to derive, is the battery case 1 according to the embodiment of the 1 with an outflow opening 8th provided the internal volume 6 Fluid conducting with the environment of the battery case 1 combines.

The battery case 1 is designed in particular for use in a motor vehicle, since the orientation of the outflow opening 8th across the floor 2 the removal of fluid from the internal volume 6 accelerated while driving the motor vehicle. Will the battery case 1 namely so installed in the motor vehicle that the outflow opening 8th opens against a ride and preferably against a forward direction D of the motor vehicle, so the airstream W in an opening direction R, in which the outflow opening 8th opens to the outside, at the outflow opening 8th flow past and create a negative pressure, which is the condensation from the outflow 8th sucks.

Thus the airstream W the outflow opening 8th as undisturbed flow around or can flow past it, is the outflow opening 8th in the embodiment of 1 spaced from the ground 2 as well as the side walls 4 . 5 arranged.

By the wind W is at the outflow opening 8th a dynamic negative pressure generated by the ground 2 located liquid from the battery case 1 is sucked out. Other gas streams oriented in accordance with the airstream W, for example weather-related wind, can also generate a sufficiently large dynamic negative pressure.

To the Fahrtwind W possible turbulence at the outflow 8th can flow past, the outflow opening 8th at one end of an at least partially horizontally extending drainage pipe 9 be educated. The drainage pipe 9 for example, is a straight piece of pipe passing through one of the side walls 4 . 5 with a drainage opening 10 into the inner volume 6 empties. Bound by one of the side walls 4 . 5 extending drain opening 10 to the ground 2 On, so condensation can easily through the drain opening 10 in the drainage pipe 9 occur and is caused by the negative pressure caused by the wind in the direction of the outflow opening 8th and from there the battery case 1 sucked.

So that the condensation even easier through the drain opening 10 in the drainage pipe 9 can flow, can the drain hole 10 through the ground 2 extend and in particular at its lowest point in the interior of the battery case 1 lead. An estuary 11 the drain opening 10 can be arranged so that it is on the ground 2 accumulated condensation of gravity following and without a hurdle to have to overcome in the drainage pipe 9 can flow into it.

In the embodiment of 1 is the battery case 1 shown mounted in a motor vehicle. The battery case 1 is for example on a vehicle floor 12 of the motor vehicle mounted. For example, the battery case 1 with fasteners 13 . 14 on the vehicle floor 12 be attached. The fasteners 13 . 14 can be designed so that the ground 2 of the battery case 1 spaced from the vehicle floor 12 is arranged. Will the vehicle floor 12 damaged for example by placing the motor vehicle, so at least cause minor damage to the vehicle floor 12 due to the distance to the ground 2 of the battery case 1 not to damage the battery case 1 ,

Thus the airstream W at the outflow opening 8th can flow past, this is from the battery case 1 seen from beyond the vehicle floor 12 or behind or under the vehicle floor 12 and for example between the vehicle floor 12 and a roadway for the motor vehicle.

The drainage pipe 9 bridges the distance between the outflow opening 8th and the drainage hole 10 Fluid conducting. This can be the drainage pipe 9 through the vehicle floor 12 extend through.

Especially if the drain hole 10 in the ground 2 arranged, can be a vertical section 15 the drainage pipe 9 from the mouth 11 along a drainage path P in the direction of the vehicle floor 12 and extend through it. In the vertical section 15 can condensation in a vertical from the ground 2 to the vehicle floor 12 pointing drainage direction E1 flow alone due to gravity.

The outflow opening 8th can be at one end of a horizontal section 16 the drainage pipe 9 be arranged. The horizontal section 16 connects the outflow opening 8th with the vertical section 15 Fluid conductive, so out of the inner volume 6 through the mouth 11 in the drainage pipe 9 and in particular in its vertical section 15 occurred condensation through the horizontal section 16 to the outflow opening 8th can get. In the horizontal section 16 the drainage path P runs horizontally and out of the inner volume 6 outflowing condensed water flows along a drainage direction E2 in the direction of the outflow opening 8th and from the outflow opening 8th out.

2 shows a further embodiment of the battery housing according to the invention 1 , where in the 2 only part of the drainage pipe 9 is shown enlarged.

In the embodiment of 2 is the battery case 1 with a liquid barrier 17 Mistake. The liquid barrier 17 is formed, liquid, such as water, from entering the drainage pipe 9 through the outflow opening 8th to prevent. At the same time the liquid barrier ensures 17 that liquid from the inner volume 6 of the battery case 1 in the drainage direction E2 to the outflow opening 8th can flow. In particular, the condensation can liquid barrier 17 happen when at the outflow opening 8th in terms of the internal volume 6 a negative pressure is applied.

The liquid barrier 17 is in the embodiment of 2 with a sealing element 18 provided, the sealing and, for example, the discharge opening 8th against drainage direction E2 closing in the drainage pipe 9 and especially in the horizontal section 16 the drainage pipe 9 is arranged. The sealing element 18 is with a circumferential sealing lip 19 shown sealingly on an inside 20 the drainage pipe 9 is applied. The sealing element 18 can in a plane perpendicular to the plane of the cutting plane to the cross section of the drainage pipe 9 have complementary cross-section. Is the drainage pipe 9 or their horizontal section 16 for example, tubular and formed with a round inner cross-section, so the sealing element 18 with its circumferential sealing lip 19 be trained.

The sealing lip 19 is on the outflow opening 8th too bent and presses with one side S flat against the inside 20 , whereby the side S of the sealing lip 19 sealing on the inside 20 lies flat. The side S borders on a free end 21 the sealing lip 19 on, with the free end 21 towards the outflow opening 8th from the drainage pipe 9 points out. Now seeks liquid against the drainage direction E2 in the outflow opening 8th penetrate, so is the circumferential sealing lip 19 and in particular its side S by the penetrating liquid stronger against the inside 20 pressed, whereby the sealing effect of the sealing lip 19 reinforced and the water from entering the battery case 1 is prevented.

However, if there is liquid in one in the dewatering direction E2 in front of the sealing element 18 arranged interior volume 22 the drainage pipe 9 , so this liquid, for example, by its own weight against the sealing lip 19 Press and this from the inside 20 the drainage pipe 9 lift off and flow out. If the weight pressure of the liquid is not sufficient, it leads through the wind W behind the sealing element 18 or at the outflow opening 8th generated negative pressure that the liquid between the sealing lip 19 and the inside 20 through the outflow opening 8th is sucked.

The orientation of the sealing lip 19 Can be easily generated by the sealing lip 19 elastically formed and the sealing element 18 against the drainage direction E2 in the drainage pipe 19 is used.

Fluid flows at the lip 19 from the inner volume 6 past the outflow opening 8th However, it may be that the sealing element 18 from the drainage pipe 9 flushed out or sucked out by the negative pressure. Consequently, the sealing element 18 preferably relative to the drainage line 9 fixed in place. For example, the sealing element 18 on the inside 20 the drainage pipe 9 be attached. Inside the drainage pipe 9 However, provided fasteners may obstruct the drainage of the liquid, such as condensed water. Consequently, the liquid barrier 17 on an outside 23 the drainage pipe 9 be attached and this example, a support arm 24 exhibit. A first end 25 of the support arm 24 can the sealing element 18 on a round disc, for example 28 wear. A first end 25 along the support arm 24 opposite second end 26 of the support arm 24 can on the outside 23 the drainage pipe 9 be attached. For example, the holding arm 24 positive or non-positive with the drainage pipe 9 be connected. If the battery case 1 to be used with a motor vehicle and the outflow opening 8th is arranged outside and in particular below the motor vehicle, a positive or non-positive connection between the liquid barrier 17 and the drainage pipe 9 However, a long-term stable attachment of the liquid barrier 17 at the drainage pipe 9 may not guarantee. By a cohesive connection, such as a welded joint 27 , is the second end 26 of the support arm 24 more stable and protected against accidental release of the connection with the drainage pipe 9 attached.

Claims (10)

Battery case ( 1 ) with an internal volume ( 6 ) for receiving at least one battery cell, and having a bottom ( 2 ), for a motor vehicle, characterized in that the battery housing ( 1 ) with an outflow opening ( 8th ), wherein the outflow opening ( 8th ) Fluid conducting with a to the ground ( 2 ) adjacent section of the internal volume ( 6 ) and substantially transverse to the ground ( 2 ) is opening. Battery case ( 1 ) according to claim 1, characterized in that the battery housing ( 1 ) one to the ground ( 2 ) adjacent drainage opening ( 10 ) through a drainage line ( 9 ) with the outflow opening ( 8th ) connected is. Battery case ( 1 ) according to claim 2, characterized in that the drainage opening ( 10 ) in the ground ( 2 ) is arranged. Battery case ( 1 ) according to claim 2 or 3, characterized in that the outflow opening ( 10 ) substantially parallel to the ground ( 2 ) into the inner volume ( 6 ) opens. Battery case ( 1 ) according to one of claims 2 to 4, characterized by a liquid barrier ( 17 ), which at least partially in the drainage line ( 9 ) is arranged and formed, no liquid from the outflow opening ( 8th ) to the drainage opening ( 10 ) to flow. Battery case ( 1 ) according to claim 5, characterized in that the liquid barrier ( 17 ) with a circumferential sealing lip ( 19 ) having sealing element ( 18 ), wherein the sealing lip ( 19 ) sealing on an inner side ( 20 ) of the drainage line ( 9 ) is present. Battery case ( 1 ) according to claim 6, characterized in that a free end ( 21 ) of the sealing lip ( 19 ) along the drainage line ( 9 ) on the outflow opening ( 8th ) to assign. Battery with an internal volume ( 6 ) and a floor ( 2 ) having battery housing ( 1 ) and at least one in the inner volume ( 6 ) arranged battery cell, characterized in that the battery housing ( 1 ) a battery case ( 1 ) according to one of claims 1 to 7. Motor vehicle with a drive power for a drive device of the motor vehicle battery providing, characterized in that the battery is a battery according to claim 8. Motor vehicle according to claim 9, characterized in that the outflow opening ( 8th ) opens against a forward direction (D) of the motor vehicle.

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