Adhesive bead, a battery cell arrangement comprising the adhesive bead, a battery, a motor vehicle and a method for producing the battery cell arrangement

Abstract

The present invention relates to an adhesive bead (1) which is designed to adhere and / or space at least two battery cells (4) together. It comprises an adhesive (2) and a heat-resistant element (3) which is designed as a spacer for the battery cells and has a greater temperature resistance than the adhesive. The adhesive (2) comprises the heat-resistant element (3) or the heat-resistant element (3) is embedded in the adhesive (2). The adhesive bead (1) is arranged between the battery cells (4) in a battery cell arrangement (5) which comprises at least one row (6, 7, 8) comprising at least one battery cell (4), wherein optionally several rows (6, 7, 8) lie on top of one another.The adhesive bead (4) spaces the battery cells (4) of the respective rows (6, 7, 8) and, by means of the heat-resistant element (3), maintains a minimum distance between the battery cells (4) in the battery cell arrangement (5) at relatively high temperatures in order to prevent a short circuit between two battery cells (4).

Description

Technical FieldThe present invention relates to an adhesive bead, a battery cell arrangement comprising the adhesive bead, a battery, a motor vehicle and a method for producing the battery cell arrangement.Prior ArtBattery modules or batteries may be composed of a plurality of battery cells. The battery cells, for example cylindrical cells, can be held together structurally by means of adhesives, wherein the adhesive for this purpose is arranged, for example, in adhesive beads between the cells and thus connects these to one another. After curing, the adhesive beads serve not only to mechanically connect the battery cells to one another, but also ensure that the battery cells have a predefined spacing from one another.In the case of thermal propagation of battery cells connected to one another by means of adhesive beads in a battery or a battery module, the adhesive beads may fail thermally. In this case, the adhesive function is not primarily to be understood as meaning, but rather the property that the battery cells are kept at a distance. This function can fail as a result of the action of heat and the battery cells can come into contact with one another, which can lead to a short circuit or to a thermal runaway of the cell or to thermal propagation to further cells.For this purpose, a battery module is known from WO 2022 / 114057 A1. A battery pack is known from US 2021 / 0184190 A1. CN 204741056 U discloses a power battery group with a homogeneous battery temperature structure.SUMMARY OF THE INVENTIONProceeding from the known prior art, it is an object of the present invention to provide an improved adhesive bead, an improved battery cell arrangement, an improved battery and an improved motor vehicle and a corresponding method.The object is achieved by an adhesive bead having the features of claim 1. Advantageous refinements emerge from the dependent claims, the description and the figures.Accordingly, an adhesive bead is proposed, which is designed to glue and / or space at least two battery cells to one another, and comprises an adhesive.According to the invention, a heat-resistant element is provided as a spacer for the battery cells, which element has a greater temperature resistance than the adhesive.In other words, the adhesive bead can be configured to glue at least two battery cells to one another and / or to provide a spacer between at least two battery cells.A greater temperature resistance may mean that the heat-resistant element is configured to maintain its shape and / or structure at a temperature at which the adhesive melts.Temperature resistance can mean, in particular, that the heat-resistant element at least partially retains its shape and / or its structure in the case of a thermal runaway of a battery cell, such that a minimum distance remains between at least two battery cells. Spacing may mean here that the adhesive bead, in particular the heat-resistant element, provides a spacer for maintaining a minimum distance of at least two battery cells and / or is designed as a spacer between at least two battery cells.In addition, the heat-resistant element and / or the adhesive can be designed to be electrically insulating.This results in the advantage that at an elevated temperature of a battery cell, which occurs, for example, in the case of a thermal runaway, a minimum distance between at least two battery cells is maintained, so that contacting of two battery cells and thus a short circuit can be prevented. This can brake or prevent the thermal runaway from spreading to other battery cells.Furthermore, it can be provided that the adhesive can comprise the heat-resistant element, wherein in particular the heat-resistant element can be embedded in the adhesive. In other words, the adhesive bead may be formed of a layer including the adhesive in which the heat-resistant member is integrated. This results in the advantage that installation space is saved and an energy density of the battery can thus be increased.Furthermore, it can be provided that the heat-resistant element can be formed as a cord or as a mat or as a grid, which can run along a longitudinal direction and / or along a transverse direction orthogonal to the longitudinal direction. In other words, the heat-resistant element can have the same length and / or width as the adhesive and / or as the adhesive bead.In addition, the adhesive bead can comprise at least two heat-resistant elements crossing one another in the longitudinal direction and the transverse direction. In particular, the at least two crossing heat-resistant elements, in particular two cords crossing one another in the longitudinal direction and the transverse direction, can form the lattice.This results in the advantage that a mechanical stability of the heat-resistant element can be improved.Furthermore, it can be provided that the cord or the mat or the grid can run continuously along a length in the longitudinal direction and / or along a width in the transverse direction. In other words, the cord or mat or grid may have the same length in the longitudinal direction and / or the same width in the transverse direction as the adhesive and / or as the adhesive bead. This results in the advantage that when arranging the adhesive bead on at least one battery cell in a row of a battery cell arrangement, the heat-resistant element is under mechanical tension.In addition, the mechanical stress can be dimensioned such that the heat-resistant element can bear a force of gravity of a battery cell.Furthermore, it can be provided that the heat-resistant element can comprise a glass fiber and / or an aramid fiber and / or the adhesive can be formed as an adhesive that gives a plastic structure. In other words, the cord or mat or grid may comprise or be formed from glass and / or aramid fibers.In this case, the cord or the mat or the grid can be designed to hold the battery cell, in particular at a relatively high temperature at which the adhesive can melt, in particular the force of gravity of at least one or more battery cells. This results in the advantage that the heat-resistant element can maintain its shape and / or structure at least partially even at relatively high temperatures, which occur, for example, in the case of a thermal runaway of a battery cell. As a result, a minimum distance of at least two battery cells to one another can be maintained at a temperature at which the adhesive melts.The object is furthermore achieved by a battery cell arrangement having the features of claim 6. Advantageous refinements emerge from the dependent claims, the description and the figures.Accordingly, a battery cell arrangement is proposed which comprises at least one row comprising at least one battery cell, wherein optionally a plurality of rows lie on top of one another.According to the invention, in the battery cell arrangement between the battery cells, the said adhesive bead is arranged on a battery cell wall of the battery cell.In other words, the adhesive arrangement can be arranged in the battery cell arrangement between the battery cells, in particular between at least two rows of battery cells. In this case, the adhesive bead can be arranged on a battery cell wall of the respective battery cell in the row in such a way that at least two battery cells of the row are adhesively bonded to one another. The rows can be adjacent to one another or lie on top of one another along a height direction orthogonal to the longitudinal direction and to the transverse direction. As a result, the battery cells are held in their position for electrical interconnection with one another. The battery cells can be cylindrical battery cells, on the battery cell wall of which the adhesive bead is arranged.The adhesive bead can be arranged adheringly on the battery cell wall of the respective battery cell in the row or of at least two rows, in particular by means of the adhesive. The adhesive bead may have a length along the longitudinal direction such that all battery cells of the row or of at least two rows are bonded to one another.In addition, the adhesive bead can be designed to fix the respective row to a housing wall of a battery housing or battery module housing.By means of the heat-resistant element, a minimum distance between the battery cells in a row or between different rows can be maintained at a temperature at which the adhesive of the adhesive bead melts.This results in the advantage that without requiring more installation space, a risk of a short circuit of two battery cells is reduced and thus a propagation of a thermal pathway to other battery cells is braked or prevented.Furthermore, it can be provided that the adhesive bead can be designed to glue the battery cells to one another, in particular in the row, along a longitudinal direction and / or to space the battery cells, in particular from different rows, from one another and / or from a housing wall. In other words, the adhesive bead can be configured to glue the battery cells of one row or of two rows to one another by means of the adhesive. For this purpose, the adhesive bead can be arranged by means of the adhesive in an adhering manner on a battery cell wall of the respective battery cell and optionally designed to mechanically connect the battery cells to one another by means of their structural strength. This results in the advantage that a minimum distance between the battery cells is maintained, which prevents a short circuit between two battery cells.Furthermore, it can be provided that along a transverse direction orthogonal to the longitudinal direction, the width of the adhesive bead, in particular of the adhesive and / or of the heat-resistant element, can be smaller than a height of the battery cell wall of the respective battery cell in the row. In other words, the adhesive bead may be narrower than the width of the battery cell wall, such that the battery cell wall of the respective battery cell in the row remains at least uncovered or free. This results in the advantage that the respective battery cell can be cooled better.Furthermore, it can be provided that at least two adhesive beads can be arranged next to one another on the battery cell wall of the respective battery cell in the transverse direction, wherein the battery cell wall of the respective battery cells in the row between the adhesive beads remains free along the transverse direction. This results in the advantage that a proportion of the battery cell wall which remains free or uncovered can be further enlarged, which further improves a cooling property of the respective battery cell.Furthermore, it can be provided that the two adhesive beads can form a flow channel for a cooling medium along the longitudinal direction. In other words, the adhesive bead can be arranged, in particular arranged adhesively, in each case for a liquid in a sealing manner on the battery cell wall of the respective battery cell, such that the liquid cannot pass through the adhesive bead. For this purpose, the adhesive can be liquid-resistant, in particular water- or oil-resistant. As a result, a flow channel for a cooling medium can be formed between the adhesive beads on the battery cell wall of the respective battery cell along the longitudinal direction and the respective row. The cooling medium can be water or an oil. Furthermore, the battery housing or the battery module housing can comprise an access and an outlet for the cooling medium at a height of the respective row, such that the cooling medium can flow around the battery cells, in particular from the access to the outlet, along the respective row. This results in the advantage that better heat dissipation can be provided.The object is furthermore achieved by a battery having the features of claim 11.Accordingly, a battery is proposed which comprises said adhesive bead and / or said battery cell arrangement. The battery may also be a battery system or a battery module or a battery pack. The battery or the battery system can comprise a plurality of battery modules or battery packs which are spatially distributed in a motor vehicle, but can be connected to a charging device and / or an electrical load via a common connection. The battery can be provided in particular as a drive battery of an electric motor driving the motor vehicle.The object is furthermore achieved by motor vehicles having the features of claim 12. The motor vehicle can preferably be designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle. The motor vehicle may be electrically powered (EV) or, in particular, a hybrid electric vehicle (HEV, PHEV), wherein the components provided for this purpose in the motor vehicle may each be an electrical load of the battery.The object set out above is furthermore achieved by a method for producing the battery cell arrangement having the features of claim 13. Advantageous refinements of the method are evident from the dependent claims and from the present description and the figures.Accordingly, a method for producing said battery cell arrangement is proposed, which comprises the step:arranging said adhesive bead on a battery cell wall of at least one battery cell and / or between at least two battery cells.In other words, said adhesive bead can be used for adhering battery cells in a battery cell arrangement, in particular in a row of battery cells in the battery cell arrangement, to one another. Furthermore, the respective rows of battery cells can be placed next to one another or placed one on top of the other in particular along the height direction.In addition, the respective rows can be glued to one another, in particular by means of the adhesive bead. By placing the respective rows next to one another or placing them one on top of the other, a flow channel can additionally be formed between at least two rows by means of at least further adhesive beads. For this purpose, the respective adhesive bead can be designed to connect the battery cells of two different rows to one another in a sealing manner with respect to a liquid, in particular to adhere them in a sealing manner to the battery cell wall of the respective battery cell.This results in the advantage that the risk of a short circuit can be reduced without requiring more installation space.The invention also comprises implementations comprising a combination of the features of a plurality of the described embodiments, in particular of the adhesive bead and / or of the battery cell arrangement and / or of the battery and / or of the motor vehicle and / or of the method.Brief Description of the FiguresPreferred further embodiments of the invention are explained in more detail by the following description of the figures. The following are shown: FIG. 1 shows a motor vehicle comprising a battery which comprises the battery cell arrangement, in which the battery cells are adhesively bonded together by means of the adhesive bead; and FIG. 2 is a more detailed view of the arrangement of the heat-resistant element in the adhesive bead.DETAILED DESCRIPTION OF PREFERRED EMBODIMENTSPreferred exemplary embodiments are described below with reference to the figures. Identical, similar or identically acting elements are provided with identical reference symbols in the different figures, and a repeated description of these elements is partly omitted in order to avoid redundancies.FIG. 1 schematically illustrates a motor vehicle 13 which comprises a battery 12. The battery 12 can be designed to supply an electrical load of the motor vehicle 13 with electrical energy. The electrical load can be, for example, an electric motor, which can be, in particular, a drive motor of the motor vehicle 13. The battery 12 comprises at least one battery cell arrangement 5, which is arranged in the battery housing 14.The battery housing 14 can be a battery module housing or a battery pack housing, wherein optionally the battery 12 can be designed as a battery system. The battery cell arrangement 5 comprises a plurality of battery cells 4 which are arranged in rows 6 along a longitudinal direction x. The rows 6 comprising the battery cells 4 are arranged next to one another or lying on top of one another in a height direction z. In this case, the black and gray points of the battery cells 4 in FIG. 1 represent different pole connections of the respective battery cell 4 on the right, wherein the battery cells 4 can be arranged in the battery cell arrangement 5 in a differently oriented manner in accordance with a switching arrangement of the battery 12 or of the battery module in accordance with their pole connection. The battery cells 4 are here cylindrical battery cells 4.In order to fix the battery cells 4 in their position, they are bonded to one another, in particular row by row, by means of an adhesive bead 1. The adhesive bead 1 may adhere the battery cells 4 to one another in a row 6 or a first row 7 and a second row 8. The adhesive bead 1 is designed to space the battery cells 4 apart from one another, in particular to space at least two battery cells 4 from different rows 7 and 8 apart from one another. Spacing here means that the adhesive bead 1 functions as a spacer. The adhesive bead 1 is thus designed as a spacer between the battery cells 4, in particular along a height direction z.The adhesive bead 1 is designed to glue the battery cells 4 of the first row 7 and of the second row 8 to one another and thus to fix them to one another in a position. In this case, the battery cells 4 in all rows 6 of the battery cell arrangement 5 are fixed to one another by means of a respective adhesive bead 1 (not illustrated!), in order to fix these in their respective position for electrical interconnection. The adhesive bead 1 is additionally designed to space the battery cells 4 apart from one another. The battery cells 4 can be in the same first row 7 or in the row 8.In addition, the adhesive bead 1 can be designed to glue the battery cells 4 in the first row 7 and the second row 8 to one another and to space the battery cells 4 in the first row 7 from the battery cells 4 in the second row 8 from one another.In addition, the adhesive bead 1 can be arranged between the first row 7 and a housing wall 10 of the battery housing 14 and can be designed to space the respective battery cell 4 of the first row 7 from the housing wall 10.FIG. 2 shows a more detailed illustration of the battery cell arrangement 5 in the battery housing 14 in the battery 12, wherein the battery cells 4 are arranged or bonded to one another in a row 6, 7 and 8 in each case by means of the adhesive bead 1. The adhesive bead 1 can have a length along the longitudinal direction x, so that all battery cells 4 of the row 6 or between the rows 7 and 8 can be bonded to one another. In addition, the adhesive bead 1 can be designed to fix the battery cells 4 of the row 6 to the housing wall 10.In FIG. 2, at the top right, a detailed view of the arrangement of at least one adhesive bead 4 on the battery cell wall 9 of the battery cell 4 is shown. The adhesive bead 4 extends along the longitudinal direction x along the row 6 and thus fixes the battery cells 4 to one another. For this purpose, the adhesive bead 4 adheres to the battery cell wall 9 of the respective battery cell 4 by means of the adhesive 2.The adhesive bead 1 is arranged on a battery cell wall 9 of the respective battery cell according to the upper right in FIG. 2 in the transverse direction y, so that it is located between at least two battery cells 4 and / or the housing wall 10. The adhesive bead 1 adheres to the battery cell wall 9 by means of an adhesive 2. The adhesive 2 can be designed as a structural adhesive which has a plastic structure and / or gives the adhesive bead 1 a plastic structure. For example, the adhesive bead may comprise a mat comprising the structural adhesive. In this case, the adhesive 2, in particular the structural adhesive, can glue the battery cells 4 to one another and thus fix them in their position in the row 6.In addition, the adhesive 2, in particular the structural adhesive 2, is configured to provide a spacer between the battery cells 4 of the row 6 and / or between the rows 7 and 8.The problem here is that in the case of relatively strong heating of a battery cell 4, for example by a thermal runaway, the adhesive 2 can melt and therefore no longer function as a spacer. As a result, the relatively strongly heating battery cell 4 can contact other battery cells 4 and form a short circuit with the other battery cell 4, which can lead to a more rapid propagation of the thermal runaway.In order to prevent a short circuit between the battery cells 4 and thus at least to brake or prevent a propagation of the thermal runaway, the adhesive bead 4 has a heat-resistant element 3 which is designed to provide a spacer between the battery cells 4.Furthermore, the heat-resistant element 3 has a greater temperature resistance or heat resistance than the adhesive 2. temperature resistance here can mean that the heat-resistant element 3 is configured to still provide the spacer between the battery cells at a temperature, in particular a thermal runaway, at which the adhesive 2 melts. As a result, even in the case of a melting adhesive 2, the distance between the battery cells 4 can be held and a short circuit prevented. As a result, it is possible to brake or prevent attachment of other battery cells 4 and thus propagation of a thermal runaway of an individual battery cell 4.In FIG. 2, the arrangement of the heat-resistant element 3 in the adhesive bead 1, in particular in the adhesive 2 of the adhesive bead 1, is shown at the bottom right. The adhesive bead 1 and / or the adhesive 2 can comprise the heat-resistant element 3, wherein in particular the heat-resistant element 3 is embedded in the adhesive 2 or an adhesive 2 layer of the adhesive bead. In this case, the heat-resistant element 3 extends along the longitudinal direction x over the same length as the adhesive bead 1.The heat-resistant element 3 can be formed as a cord or as a mat or as a grid. For satisfying the temperature strength, the heat-resistant member 3 includes a glass fiber and / or an aramid fiber. Glass and aramid have good thermal properties, in particular with respect to a dimensional stability at relatively high temperatures, where the adhesive 2 loses its dimensional stability. In particular, the cord or mat or grid is or is formed from the glass and / or aramid fibers.In addition, the adhesive bead 1 in the battery cell arrangement 5, in particular the heat-resistant element 3, is under a mechanical stress, such that, when the adhesive 2 melts, the battery cell 4 is held in its position by the heat-resistant element 3, in particular under the action of at least its force of gravity.As shown at the top right in FIG. 2, the adhesive bead 1 in the transverse direction y can have a width which is smaller than a height of the battery cell wall 9 in the transverse direction. As a result, a part of the battery cell wall 9 remains free, which can be cooled better as a result.In addition, at least two adhesive beads 1 can be arranged on the battery cell wall 9 of the respective battery cell 4 in the transverse direction y in a row 6 along the longitudinal direction x, the width of which is in each case smaller than the height of the battery cell wall 9 of the respective battery cell 4 in the transverse direction y. The battery cell wall 9 remains free between the adhesive beads 1, in particular along the transverse direction y.In addition, the adhesive bead 1 is designed to adhere sealingly, in particular for a liquid, to the battery cell wall 9 of the respective battery cell 4 in the row 6, so that a flow channel 11 for a cooling medium is provided between the at least two adhesive beads 1, in particular between the rows 7 and 8 and / or between the row 6 and the housing wall 10. The cooling medium can be a liquid, such as a water or an oil, for example, which flows around the battery cells 4 along the longitudinal direction x, in particular in the battery housing 14, for the purpose of heat dissipation.The concept consists in keeping the battery cells at a distance despite a possible thermal failure of the adhesive bead and thus preventing contact or a short circuit. This is to be done by a cord of glass or aramid fiber placed in or next to the adhesive bead, between the individual battery cell rows.Glass and aramid fibers are high-temperature and thus dimensionally stable and keep the battery cells at a distance. The glass or aramid fiber cord and / or mat and / or grid keep the battery cells at a distance if the adhesive bead, which actually fulfills this function, fails due to thermal propagation. Short circuits due to contacting battery cells are thus prevented.Overall, the example shows an adhesive bead having a "retaining cord" introduced in particular in the adhesive as a spacer between at least two battery cells, which comprises the heat-resistant element.Where applicable, all individual features illustrated in the exemplary embodiments can be combined with one another and / or interchanged without departing from the scope of the invention.List of reference characters1 Adhesive bead 2 Adhesive 3 Heat-resistant element 4 Battery cell x Longitudinal direction y Transverse direction z Height direction 5 Battery cell arrangement 6 Row 7 First row 8 Second row 9 Battery cell wall 10 Housing wall 11 Flow channel 12 Battery 13 Motor vehicle 14 Battery housingReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedWO 2022 / 114057 A1

[0004] US 2021 / 0184190 A1

[0004] CN 204741056 U

[0004]

Claims

Adhesive bead (1) which is designed to glue and / or space at least two battery cells (4) to one another, comprising an adhesive (2), characterized in that a heat-resistant element (3) is provided which is designed as a spacer for the battery cells (4) and has a greater temperature resistance than the adhesive (2).Adhesive bead (1) according to Claim 1, characterized in that the adhesive (2) comprises the heat-resistant element (3), wherein in particular the heat-resistant element (3) is embedded in the adhesive (2).Adhesive bead (1) according to one of the preceding claims, characterized in that the heat-resistant element (3) is designed as a cord or as a mat or as a grid which runs along a longitudinal direction (x) and / or along a transverse direction (y) orthogonal to the longitudinal direction (x).Adhesive bead (1) according to claim 3, characterised in that the cord or mat or grid runs continuously along a length in the longitudinal direction (x) and / or along a width in the transverse direction (y).Adhesive bead (1) according to one of the preceding claims, characterized in that the heat-resistant element (3) comprises a glass fiber and / or an aramid fiber and / or the adhesive (2) is designed as an adhesive (2) which gives a plastic structure.Battery cell arrangement (5) comprising at least one row (6, 7, 8) comprising at least one battery cell (4), wherein optionally a plurality of rows (6, 7, 8) lie on top of one another, characterized in that an adhesive bead (1) according to one of Claims 1 to 5 is arranged on a battery cell wall (9) of the battery cell (4) between the battery cells (4).Battery cell arrangement (5) according to Claim 6, characterized in that the adhesive bead (1) is designed to glue the battery cells (4), in particular in the row (6, 7, 8), to one another along a longitudinal direction (x) and / or to space the battery cells (4), in particular from different rows (6, 7, 8), from one another and / or from a housing wall (10).Battery cell arrangement (5) according to Claim 6 or 7, characterized in that, along a transverse direction (y) orthogonal to the longitudinal direction (x), the width of the adhesive bead (1), in particular of the adhesive (2) and / or of the heat-resistant element (3), is smaller than a height of the battery cell wall of the respective battery cell (4) in the row (6, 7, 8).Battery cell arrangement (5) according to Claim 8, characterized in that at least two adhesive beads (1) are arranged next to one another on the battery cell wall (9) of the respective battery cell (4) in the transverse direction (y), wherein the battery cell wall (9) of the respective battery cells (4) in the row (6, 7, 8) remains free between the adhesive beads (1) along the transverse direction (y).Battery cell arrangement (5) according to Claim 9, characterized in that the two adhesive beads (1) form a flow duct (11) for a cooling medium along the longitudinal direction (x).Battery (12) comprising the adhesive bead (1) according to one of Claims 1 to 5 and / or the battery cell arrangement (5) according to one of Claims 6 to 10.A motor vehicle (13) comprising the battery (12) of claim 11.Method for producing the battery cell arrangement (5) according to one of Claims 6 to 10, comprising the step of: - arranging the adhesive bead (1) according to one of Claims 1 to 5 on a battery cell wall (9) of at least one battery cell (4) and / or between at least two battery cells (4).

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