Battery with flame-retardant area and flow area sealed therefrom and method for producing the same

Abstract

In various embodiments, a battery (10) is provided, comprising: a battery housing in which a battery cell arrangement is arranged; two insertion plates (16), one of which is arranged between the battery cell arrangement and one of two laterally opposite battery housing walls (17); a cover (13) which is arranged on the end face of the battery cell arrangement between the insertion plates (16) and has a sealing web (14) projecting towards the end face; wherein the sealing web (14) delimits a first region (21) from a second region (22), both of which are formed between the cover (13), end regions of the insertion plates (16), and a battery housing wall arranged on the end face; wherein a flame-retardant material is arranged in the first region (21), and the second region (22) has a free space which is designed as a gas flow region;and wherein a sealing element (18) is arranged in the contact region (5) between the sealing web (14) and the insertion plates (16). Furthermore, a method for producing the battery (10) according to the invention is provided;

Description

The present invention relates to a battery with a flame-retardant region and a flow region sealed therefrom and to methods for producing the same.In order to thermally protect (vehicle) battery(s) in the event of a thermal event of one or more battery cells, a flame-retardant substance in the form of a potting compound or a foam material can be used. This flame-retardant substance can also be used, for example, to shield the location of the (electrical, fluidic or mechanical) contacting and thereby provide a targeted directing effect for a gas jet arising from the battery cell in question. In order to be able to achieve this steering effect, a predetermined region within the battery (module) housing must remain free. The gas can flow along a predetermined path through the area left open, while no gas can enter the area in which the flame retardant is located.During the production of the battery or of the battery module, the flame-retardant substance is usually introduced into the already constructed battery module in a liquid chamfer. The restriction of the flow path and thus the propagation of the flame-retardant substance can be achieved relatively easily in two spatial directions by means of, for example, fixed walls. However, the remaining third spatial direction, which is arranged, for example, perpendicular to a housing wall of the battery or of the battery module, imposes particular requirements on tolerance compensation and is therefore difficult to seal.In this context, document DE 10 2018 213 066 A1 discloses a method for producing a battery module for a high-voltage battery of a motor vehicle, in which battery cells are arranged in a battery module housing having at least one injection opening and are interconnected with one another, after which the battery module housing is closed and then a fire-retardant and electrically insulating sealant is introduced through the injection opening into the closed battery module housing until interstices present in the battery module housing are filled by the sealant and the battery module housing is sealed off from the outside by the sealant.From document DE 10 2015 219 280 A1, a method for producing a battery system is known, in which battery cells are positioned by at least one mounting grid for positioning battery cells and / or by positioning ribs and / or positioning projections in the interior of a battery system housing or a potting mold, which are designed for positioning battery cells, and / or by a mounting gripper for positioning battery cells and are at least partially potted with at least one potting compound.US 2023 / 0231266 A1 discloses a battery module having a cell assembly including a plurality of battery cells, and a module case having an arrangement space for accommodating the cell assembly, and a cover plate covering an upper surface of the cell assembly. The cover plate has at least one outlet hole for discharging gas generated in the cell assembly. A blocking element is disposed between the top of the cell assembly and the cover plate to prevent a flame or combustion material from exiting outside the module housing through the outlet opening.WO2024 / 120869 A1 discloses a battery assembly configured to receive a plurality of battery cells at respective predetermined locations, the battery assembly comprising a plurality of vent openings located at the predetermined locations and at least one vent channel extending adjacent to at least a first subset of the predetermined locations. The vent openings located at the first subset of the predetermined locations are configured to allow material ejected from a battery cell located at a respective one of the predetermined locations to exit therethrough and into the at least one vent passage. The at least one vent channel includes an open-cell foam at least adjacent the vent openings to receive the material exiting through the vent openings.In KR 102023171074 A, a battery case with an automatic fire extinguishing unit is described, which includes a lower cover for accommodating a battery pack; first and second flame bypass guide units disposed to face each other with the battery pack interposed therebetween; a blocking plate disposed on the first and second flame bypass guide units to block flames and smoke generated in the battery unit; a fire extinguishing unit disposed on a lower surface of the blocking plate to extinguish the fire after the fire generated in the battery pack is detected; and an upper cover having a plurality of outlets for discharging the smoke guided in the blocking plate to the outside. The fire extinguishing unit includes a fire extinguishing pad made up of a fire extinguishing capsule layer including fire extinguishing capsules into which a fire extinguishing liquid is injected, and a flame retardant layer disposed so as to be stacked on the fire extinguishing capsule layer.The object of the present invention can be seen in providing a reliable seal of the flame-retardant region with respect to the flow region separated therefrom in such a way that tolerance compensation is still possible to a certain extent.This object is achieved by means of the subject matter of the independent claims. Further preferred embodiments are found in the dependent claims.According to the invention, a battery is provided which has a battery housing in which a battery cell arrangement is arranged, two insertion plates, of which in each case one is arranged between the battery cell arrangement and one of two opposite lateral battery housing walls, and a cover which is arranged on the end face of the battery cell arrangement between the insertion plates and has a sealing web projecting toward the end face.The battery can be the largest unit, considered systemically, or else a battery module, of which usually a plurality can be interconnected to form a battery and, in addition thereto, can also be arranged in a battery housing. In the following, the term battery housing is therefore also intended to include a battery module housing. The battery cell arrangement can be a single number of battery cells electrically interconnected to one another, regardless of the type of housing.The insertion plates, which can preferably be manufactured from a glass fiber-reinforced plastic (GRP), constitute an insertion aid which serves for inserting or inserting the battery cell arrangement into the battery housing. After the battery cell arrangement has been inserted, they remain in the battery housing on two opposite sides of the battery cell arrangement between the latter and side walls of the battery housing. In this case, the insertion plates can preferably extend beyond the cover toward the end side of the battery cell arrangement, against which the cover abuts.The battery according to the invention is furthermore configured such that the sealing web delimits a first region from a second region, both of which are formed / defined between the cover, end regions of the insertion plates and a battery housing wall arranged on the end face. If one looks frontally perpendicular to the bearing direction of the cover on the battery cell stack, the sealing web can provide a subdivision of the space in front of the cover in the vertical direction, while the end regions of the insertion plates extending beyond the cover laterally delimit this space and at the same time determine its depth (the longer the end regions of the insertion plates the deeper the space in front of the cover). On the side facing away from the cover, the depth of the space is limited by the cover of the battery housing.The basic depth of the battery, i.e. the space between the two battery housing covers, can be occupied or filled by at least one, preferably by two or more battery cell stacks. The depth available for the region between a housing wall of the battery as the outermost boundary of the battery and the cover upstream thereof in the depth direction can additionally be adjusted by a block or plate-like element. The block-like member may be disposed between the battery cell stacks.In the first region of the space, a flame retardant is arranged or filled. The second region, which has a free space, is configured as a gas flow region. The second region can preferably be hollow.The battery according to the invention is furthermore designed such that a sealing element is arranged in each case in the contact region between the sealing web and the insertion plates. With the sealing element, the first region, which accommodates the flame-retardant substance, is sealed off from the second region, preferably in a fluid-tight manner, but particularly preferably in a gas-tight manner, which is designed as a gas flow region.The insertion plates serving as an insertion aid are to be pressed by the sealing element onto the housing wall in order to thus close off with the housing (virtually) without any gaps and thereby provide a sealing function. The sealing element can be used to compensate for the fluctuations in tolerances which occur in the process and also to close the gap, which is subject to fluctuations, between the sealing web arranged on the cover and the insertion plates.Depending on the embodiment of the sealing element, it can be applied both to the insertion plates or be supplied with it pre-coated thereon or also to the sealing web of the cover or be supplied with it pre-coated thereon. For example, the sealing element can be injection-molded either onto the edges of the sealing web or onto the insertion plates.According to further embodiments of the battery according to the invention, the sealing element can be an element which surrounds the end region of the sealing web. The sealing element can be designed as a plug-on part and can thus be attached with a clamping action, in a force-fit and form-fit manner to the edge of the sealing web. In particular, the sealing element can be mountable without tools.According to further embodiments of the battery according to the invention, the sealing element may comprise an elastomer or a foam material, whereby the sealing element may be very resilient. The sealing element can be designed as an elastomer molded part in order to compensate for the occurring tolerances, as well as to press against the insertion plates by the injection & expansion force of the flame-retardant substance, in order to achieve a sealing effect. In the case of an elastomer seal, it can also be designed as a sealing bead which is arranged either on the insertion plates or on the sealing web.According to further embodiments of the battery according to the invention, the sealing web can have a T-shaped form in such a way that its end region is widened relative to its main part.According to further embodiments of the battery according to the invention, the sealing element can be pressed between the end region of the sealing web and an insertion plate. The sealing element can be designed, for example, as an elastomer seal with a high compressibility.According to the invention, a method for producing a battery is also provided, in particular the battery described above. In a first step, the method comprises providing a battery cell arrangement which is to be introduced into a corresponding battery housing.In a further step, the method according to the invention comprises placing a cover on the end face of the battery cell arrangement, wherein the latter has a sealing web projecting to the outer side. In a further step, the method according to the invention comprises placing two insertion plates on the battery cell arrangement, one of which is in each case in contact laterally with the battery cell arrangement. In a further step, the method according to the invention comprises inserting the battery cell arrangement together with the insertion plates into the battery housing, wherein each of the insertion plates bears against a battery housing wall.The method according to the invention is configured such that before the insertion plates are placed on the battery cell arrangement, a sealing element is arranged in the contact region between the sealing web and the insertion plates. As already described in connection with the different embodiments of the battery according to the invention, the sealing element can already be pre-applied to the insertion plates or to the sealing web before the battery is manufactured or can be applied to the latter during the production of the battery.According to further embodiments of the method according to the invention, the provision of the sealing element can comprise arranging the sealing element on an end region of the sealing web, such that the latter preferably engages around the end region. In this case, the sealing element can be designed, for example, as a plug-on part.According to further embodiments of the method according to the invention, this provision of the sealing element can comprise arranging the sealing element on the insertion plates.According to further embodiments of the method according to the invention, the provision of the sealing element can comprise arranging a sealing bead on the end region of the sealing web or on the insertion plates.According to further embodiments of the method according to the invention, the sealing element can comprise an elastomer or a foam material.Further embodiments of the method according to the invention result from the corresponding steps which are required for forming the physical features of the battery according to the invention described above.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings. FIG. 1 shows a simplified illustration of a battery housing. FIG. 2 shows a perspective view of an exemplary embodiment of a battery according to the invention. FIG. 3 is an enlarged view of the contact portion between the cover and the insertion plate. FIG. 4A shows a first example of a sealed contact area between cover and insertion plate. FIG. 4B shows a second example of a sealed contact area between cover and insertion plate.FIG. 1 shows a simplified illustration of a battery housing 1 for the purpose of explaining the principal mode of operation of the present invention. The battery housing 1 is divided, at least in its end region, into two regions: a first region 21 and a second region 22. The two recesses 21, 22 are separated from one another vertically (in the z direction) by an inner wall 4 which can correspond, for example, to a sealing web, which is described in greater detail below. The first region 21 is provided for the flame-retardant substance for protecting the battery cells in the event of a thermal event. The flame-retardant substance can be present in the form of a potting compound or a foam material. Arranged underneath is the second region 22, which remains free in the battery housing 1 and provides a gas flow path. At the bottom of the battery housing 1 there is an opening 6, which is closed by a safety valve. In the event of a thermal event, the safety valve opens when the overpressure of the gas 7 flowing out of the battery cell in question is sufficiently high, which gas can then flow out of the battery housing 1.As explained in the introductory part of the description, the flame-retardant substance is to be introduced in a liquid phase in the already assembled state of the battery. The restriction of the flow path of the flame-retardant substance out of the first region 21 provided for it can be carried out quite easily in two spatial directions-in the drawing in the y-direction and in the z-direction-for example by introducing fixed walls, such as a vertical inner wall 3 and a horizontal inner wall 4 attached thereto. The present invention is concerned with sealing this same contact point 5 between a lateral boundary of the battery housing 1 and the inner wall 4.FIG. 2 shows a perspective view of an exemplary embodiment of a battery 10 according to the invention, wherein the focus here lies on the interior of the battery 10, so that only one side wall 17 of the battery housing is indicated. FIG. 3 shows an enlarged plan view in the negative y direction of the edge region of the battery 1. In both figures, the same elements are provided with the same reference numerals. A housing wall of the battery 10 which is arranged on the end face and covers the cover 13 and which at the same time represents a delimitation of the first and second region 21, 22 in the y direction has been omitted in FIG. 3.Inside the battery 10 is a battery cell arrangement which has battery cells 11 electrically connected to one another and are held together by a battery cell carrier 12. The battery cell arrangement is covered on the end face toward the outside with a cover 13. A sealing land 14 is disposed on the cover 13 to divide the space in front of the cover into the first region 21 and the second region 22, and the sealing land 14 may correspond to an integral part of the cover 13. Through an opening 15 in a component delimiting the first region 21 upward, the flame-retardant substance can be filled into the first region.On the side of the battery cell arrangement, an insertion plate 16 is arranged in each case, which serves as an insertion aid during the insertion of the battery cell arrangement, the battery housing. The insertion plates 16 are clamped between the lateral housing walls 17 of the battery 10 and the battery cell arrangement. The contact region 5 between the sealing web 14, which delimits the first region 21 in the negative z direction, and the laterally arranged insertion plate 16 provides a tolerance compensation between these two components, but at the same time should be tight so that, in the filling phase of the flame-retardant substance into the first region 21, it does not pass into the second region 22. The sealing element used according to the invention, which is described below, is intended to seal the contact region 5 between the two parts which are movable in principle with respect to one another. In the following FIGS. 4A and 4B, two exemplary embodiments thereof are described.FIGS. 4A and 4B show the enlarged plan view of the edge region of the battery 1 shown in FIG. 3. In FIG. 4A, the sealing element 18 is arranged in the contact region 5, which sealing element is designed here as an elastomer plug-on part. The sealing element 18 has a groove 19 with which it can be placed, for example without tools, on the edge of the sealing web 14. The sealing element 18 designed as a plug-on part thus develops a clamping effect on the sealing web 14 and is attached to the sealing web 14 in a force-fit and form-fit manner. Since the gap in the contact region 5 is subject to variations, tolerances in the distance between the edge of the sealing web 14 and the insertion plate 16 can be compensated by the sealing element 18 and in particular by its elasticity, with simultaneous sealing of the contact point 5.FIG. 4B shows another exemplary embodiment of the contact region 5 between the sealing web 14 and the insertion plate 16. Here, the sealing web 14 has the shape of a lying letter T, so that its end region 20 is designed widened relative to its main part. As a result, the sealing web has a larger surface at its end. The sealing element 18 is pressed or clamped between the end region 20 and the insertion plate 18, whereby the sealing effect is achieved with simultaneous tolerance compensation. In FIG. 4B, the sealing element is shown in its finally assembled pressed state. In this exemplary embodiment, the sealing element can be a sealing bead.In both cases shown in FIGS. 4A and 4B, the insertion plates 16 are pressed against the housing wall 17 by the sealing element 18, whereby they close off with the housing of the battery 10 or abut against it (virtually) without any gaps and a (labyrinth or gap) sealing function is thereby achieved. For assembly, the sealing element 18 can be mounted on the sealing web 14 or on the housing wall 17 of the battery, if required.In FIGS. 4A and 4B, only one side of the battery 10 is shown. The opposite side can be structurally identical, but designed in mirror-inverted fashion. This means that a sealing element 18 can be arranged on each of the two sides of the sealing web 14 (i.e. along the x direction). If required, the sealing element 18 can be a circumferential element which extends integrally over the entire edge of the sealing web 14 and is also arranged on the outer edge of the sealing web 14 in the y direction.

Claims

A battery (10), comprising: a battery housing in which a battery cell arrangement is arranged; two insertion plates (16), one of which is arranged in each case between the battery cell arrangement and one of two battery housing walls (17) arranged laterally opposite one another; a cover (13), which is arranged on the end face of the battery cell arrangement between the insertion plates (16) and has a sealing web (14) protruding towards the end face; wherein the sealing web (14) delimits a first region (21) from a second region (22), which are both formed between the cover (13), end regions of the insertion plates (16) and a battery housing wall arranged on the end face; wherein a flame-retardant substance is arranged in the first region (21) and the second region (22) has a free space which is arranged as a gas flow region; and wherein a sealing element (18) is arranged in each case in the contact region (5) between the sealing web (14) and the insertion plates (16).Battery (10) according to Claim 1, wherein the sealing element (18) is an element which engages around the end region of the sealing web (14).The battery (10) of claim 1 or 2, wherein the sealing member (18) comprises an elastomer or a foam material.Battery (10) according to one of Claims 1 to 3, wherein the sealing web (18) has a T-shaped form in such a way that its end region (20) is widened relative to its main part.Battery (10) according to Claim 4, wherein the sealing element (18) is pressed between the end region of the sealing web (20) and an insertion plate (16).Method for producing a battery (10), comprising: providing a battery cell arrangement; placing a cover (13) on the end face of the battery cell arrangement, wherein the latter has a sealing web (14) protruding to the outside; placing two insertion plates (16) on the battery cell arrangement, one of which each bears laterally against the battery cell arrangement, such that the sealing web (14) delimits a first region (21) from a second region (22), which are both formed between the cover (13), end regions of the insertion plates (16); inserting the battery cell arrangement together with the insertion plates (16) into a battery housing, wherein each of the insertion plates (16) bears against a lateral battery housing wall (17); filling in a flame-retardant substance into the first region (21); wherein the method further comprises, prior to the placement of the insertion plates (16) on the battery cell arrangement, providing a sealing element (18) in the contact region (5) between the sealing web (14) and the insertion plates (16).Method according to claim 6, wherein the provision of the sealing element (18) comprises arranging the sealing element (18) on an end region of the sealing web (14), such that it preferably engages around the end region.The method of claim 6, wherein providing the sealing member (18) comprises placing the sealing member (18) on the insertion plates (16).Method according to one of Claims 6 to 8, wherein the provision of the sealing element (18) comprises arranging a sealing bead on the end region of the sealing web (14) or on the insertion plates (16).A method according to any one of claims 6 to 9, wherein the sealing element (14) comprises an elastomer or a foam material.

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