Battery

Abstract

The invention relates to a battery (1) with a battery housing (2) and with battery cells (3) arranged therein, wherein the battery cells (3) are arranged as a battery cell stack (4), wherein the battery cells (3) are designed as pouch cells, wherein a pouch cell has a circumferential edge (7), wherein on one side (5) of the circumferential edge (7) of the pouch cell at least one contact element (6) is passed through the edge (7) and protrudes from the body of the pouch cell in order to serve to contact the battery cell (3), wherein on the side (5) of the battery cell (3) on which at least one contact element (6) is arranged, a foam element (8) is arranged on the battery cell (3), which foam element covers the edge (7) of the battery cell (3).

Description

[0001] The invention relates to a battery, in particular for a motor vehicle.

[0002] Electrically powered motor vehicles are known in the prior art, which comprise a battery with a battery housing and battery cells arranged therein. Such batteries, particularly those with lithium-ion cells, have the disadvantage that the battery cells can react thermally if damaged during a thermal event, generating hot gases that can damage adjacent battery cells upon escaping from the battery cell and also lead to a thermal reaction, thus creating a type of thermal chain reaction, which is highly undesirable.

[0003] CN 213 878 332 U discloses a battery with a plurality of battery cells, wherein a gas conducting structure is arranged on each side of the battery cells, wherein a foam material is provided at intervals between adjacently arranged battery cells to protect the battery cells during a thermal event. The foam material is arranged parallel to the main surfaces of the battery cells between the battery cells to allow the battery cells to expand perpendicular to the main surfaces.

[0004] However, it has been shown that in so-called pouch cells, during a thermal event, the gases produced in the battery cell escape at the edges, particularly at the side where the contact elements are led out of the cell casing. Pouch cells, which are also known as coffee bag cells, are typically constructed in such a way that several rectangular layers of negative and positive electrodes and discharge foils with corresponding layers of separators are stacked on top of each other and surrounded by a casing made of metal foil layers that are sealed at the edges, with the contact elements being led out of the casing to one side at an edge so that they can be electrically contacted. In pouch cells, the side of the edges with the contact elements led out is the weakest point and this is typically the weak point for the hot gases to escape.If the hot gases escape at this point, the foam material between adjacent battery cells does not prevent damage to other adjacent battery cells and a developing chain reaction.

[0005] The task is to create a battery which is improved over the state of the art and which helps to avoid damage to other battery cells arranged nearby and a developing chain reaction in the event of a thermal event in one battery cell.

[0006] The problem is solved with the features of claim 1.

[0007] One embodiment of the invention relates to a battery with a battery housing and with battery cells arranged therein, wherein the battery cells are arranged as a battery cell stack, wherein the battery cells are designed as pouch cells, wherein a pouch cell has a circumferential edge, wherein on one side of the circumferential edge of the pouch cell at least one contact element is passed through the edge and protrudes from the body of the pouch cell in order to serve to contact the battery cell, wherein on the side of the battery cell on which at least one contact element is arranged, a foam element is arranged on the battery cell and covers the edge of the battery cell. This implements a barrier which prevents hot gases from one battery cell from damaging other adjacent battery cells.

[0008] In one embodiment, it is also advantageous if the foam element has a predetermined breaking point. This creates a locally defined leakage point when gas escapes from a battery cell at the predetermined breaking point of the foam element, allowing the escaping gas to be dissipated in a defined manner without damaging the neighboring battery cells.

[0009] It is particularly advantageous if the foam element is designed such that one foam element is arranged for each battery cell, or one foam element is arranged for a number of battery cells, or one foam element is arranged for a battery cell stack. This simplifies assembly for just one battery cell or for more than one battery cell, depending on the design of the foam element.

[0010] It is also expedient if the foam element is designed in such a way that one foam element is arranged for each battery cell, wherein the foam element rests on the edge of the battery cell as a type of cap or lid or overlaps the edge of the battery cell, or that one foam element is arranged for each number of battery cells, wherein the foam element rests on the edge of the battery cells as a type of cap or lid or overlaps the edge of the battery cells, or that one foam element is arranged for each battery cell stack, wherein the foam element rests on the edge of the battery cells of the battery cell stack as a type of cap or lid or overlaps the edge of the battery cells of the battery cell stack. This achieves a safe design in which escaping gas can be discharged in a defined manner without damaging the adjacent battery cells.

[0011] Furthermore, it is expedient for the foam element to be made of a foam, in particular a multi-component foam that hardens, particularly after liquid application. Such a foam element is long-term stable and preferably temperature-resistant, even at high temperatures. This provides good protection for neighboring battery cells.

[0012] It is also particularly advantageous if the foam element has at least one opening, in particular a slot, for the passage of a contact element, in particular at least two openings, in particular two slots, for the passage of two contact elements of a battery cell. This allows the foam element to be placed over the contact elements of the battery cell or cells, so that the foam element rests securely and, in particular, relatively tightly against the battery cell, preventing gases from escaping laterally in an uncontrolled manner between the battery cell and the foam element and damaging neighboring battery cells.

[0013] In a further embodiment, it is also advantageous if the foam element is larger in the direction perpendicular to the main surface area of the battery cell than the thickness of the battery cell in this direction. This allows a certain distance between the battery cells, which can be used, for example, for expanding a battery cell, for swelling, or for a compressible element between two battery cells.

[0014] In one embodiment, it is also advantageous if a compressible element, in particular a compressible surface element, is arranged between two battery cells, wherein the surface element is optionally arranged such that it touches the foam element. This compressible element serves to ensure that the battery cells are arranged adjacent to one another in a defined manner and, if a battery cell expands, allows a certain degree of compensation so that the battery cell stack is not damaged by the expansion of a battery cell.

[0015] In one embodiment, it is also advantageous if the battery housing is provided with a degassing device, in particular with at least one degassing opening, in the area adjacent to or opposite the side of the battery cells on which the contact elements of the battery cells and the at least one foam element are arranged. This allows the escaping gas from a battery cell, which escapes through the foam element at the predetermined breaking point, to be safely removed from the battery housing.

[0016] In one embodiment, it is also advantageous if the battery housing consists of at least one extruded profile, wherein at least one battery cell stack is arranged in the at least one extruded profile, or at least one battery cell stack is arranged in each extruded profile. This allows for a secure design of the battery housing that is cost-effective to manufacture and allows for the necessary stability while securely arranging the battery cells.

[0017] The invention will be explained in detail below using an exemplary embodiment with reference to the drawings. In the drawings: Fig. 1 a schematic view of an embodiment of a battery, Fig. 2 a further schematic view of the embodiment of a battery according to Fig. 1, Fig. 3 a further schematic view of the embodiment of a battery according to Fig. 1, Fig. 4 a further schematic view of the embodiment of a battery according to Fig. 1, and Fig. 5 a schematic view of a battery cell of the embodiment of a battery according to Fig. 1.

[0018] The Fig. 1 to 5 show various views of a battery 1 of a motor vehicle or parts thereof. The battery 1 can also be understood as a module, i.e., a battery module, wherein several such batteries provided as battery modules can be combined to form an overall battery. Such a battery 1 is described below, wherein a plurality of such identical batteries 1 can also be combined to form an overall battery in an overall battery housing. However, the battery 1 can also be used individually.

[0019] The battery 1 is formed with a battery housing 2, wherein the battery 1 has battery cells 3 arranged in the battery housing 2.

[0020] The battery cells 3 are arranged in the battery housing 2 as a battery cell stack 4. In principle, one battery cell stack 4 can be arranged, as shown in the figures, or alternatively, several battery cell stacks 4 can be arranged.

[0021] The battery cells 3 are designed as pouch cells, wherein a pouch cell has a body and a peripheral edge 7, wherein on at least one side 5 of the peripheral edge 7 of the pouch cell, at least one contact element 6 is guided through the edge 7. In the illustrated embodiment, the battery cell 3 has two opposite sides 5, on each of which a contact element 6 is guided through the edge 7.

[0022] The contact elements 6 are designed such that they protrude from the body of the battery cell 3 as a pouch cell in order to serve for the electrical contact of the battery cell 3.

[0023] It can be seen from the figures that on at least one side 5 of the battery cell 3, on which a contact element 6 is arranged, a foam element 8 is arranged on the battery cell 3, which foam element covers the edge 7 of the battery cell 3.

[0024] It is particularly advantageous that the foam element 8 has a predetermined breaking point 9. The predetermined breaking point 9 breaks in the event of gas escaping from the battery cell 3 due to a thermal event, allowing the escaping gas to escape locally and specifically from the battery cell 3. Adjacent battery cells 3 are also provided with such a foam element 8 and covered, so that the escaping gas flows past these battery cells 3 and does not damage them.

[0025] The foam element 8 can be designed such that, as shown in the figures, one foam element 8 is arranged on each side 5 of each battery cell 3. Accordingly, the foam element 8 is designed such that one foam element 8 is arranged on each battery cell 3, wherein the foam element 8 rests on the edge 7 of the battery cell 3 as a type of cap or lid or overlaps the edge 7 of the battery cell 3. The foam element 8 thus rests relatively tightly against the edge 7 of the battery cell 3, so that escaping gas from the battery cell 3 cannot flow between the edge 7 of the battery cell 3 and the foam element 8.

[0026] Alternatively, one foam element 8 can be arranged on each side 5 for a number of battery cells 3 in such a way that one foam element 8 is arranged on each side 5 for each number of battery cells 3, wherein the foam element 8 rests as a type of cap or lid on the edge 7 of the battery cells 3 or engages over the edge 7 of the battery cells 3, or further alternatively, one foam element 8 can be arranged on each side 5 for a battery cell stack 4 in such a way that one foam element 8 is arranged on each side 5 for each battery cell stack 4, wherein the foam element 8 rests as a type of cap or lid on the edge 7 of the battery cells 3 of the battery cell stack 4 or engages over the edge 7 of the battery cells 3 of the battery cell stack 4.

[0027] Particularly preferably, the foam element 8 is formed from a cured foam, in particular from a multi-component foam that cures particularly after liquid application. It is particularly advantageous if the foam is temperature-stable, in particular up to temperatures of 300°C, 400°C, 500°C, or more. This protects adjacent battery cells 3 if hot gas escapes from one of the battery cells 3.

[0028] Furthermore, it can be seen that the foam element 8 has at least one opening 10, in particular a slot, for the passage of a contact element 6. If only one contact element 6 protrudes from the battery cell 3 on each side 5 of the battery cell 3, only one opening 10 or only one slot is useful and necessary. However, if two contact elements 6 protrude from the battery cell 3 on one side 5, it is also expedient if at least two openings 10, in particular two slots, are provided in the foam element 8 for the passage of two contact elements 6 of a battery cell 3.

[0029] According to Fig. 2 also shows that the foam element 8 is larger in the direction y perpendicular to the main surface area, i.e., in the width, of the battery cell 3 than the thickness d of the battery cell 3 in this direction. This allows a certain distance between adjacent battery cells 3, which can be used, for example, for the expansion of a battery cell 3, for swelling, or for a compressible element 11 between two battery cells 3.

[0030] The larger width of the foam element 8 can also be used to clamp the foam elements 8 of several adjacent battery cells 3 together when the battery cells 3 are stacked and to seal them off from one another or from other components.

[0031] Furthermore, it is also expedient if a compressible element 11 is arranged between two adjacently arranged battery cells 3, as is the case with Fig. 2. The compressible element 11 is a compressible surface element. It is advantageous if the compressible surface element is optionally arranged such that it touches the foam element 8. This allows expansion of a battery cell 3, a swelling, without damaging the battery cell stack 4.

[0032] Furthermore, it can be seen in the figures that the battery housing 2 is provided with a degassing device 12 in the area adjacent to or opposite the side 5 of the battery cells 3, on which the contact elements 6 of the battery cells 3 and the at least one foam element 8 are arranged. The degassing device 12 serves to discharge any gas that has arisen. It preferably has at least one degassing opening 13. In a preferred embodiment, a degassing opening 13 is essentially designed as a hole in the battery housing 2, which is closed in such a way that the hole is opened by pressure in the event of a thermal event. This can be achieved, for example, by means of a spring-loaded flap, which normally closes the hole and lifts off the hole when the internal pressure increases, thus exposing it. In a preferred embodiment, the degassing openings 13 are positioned on the underside of the battery housing 2.

[0033] It is also advantageous if the battery housing 2 consists of at least one extruded profile, wherein at least one battery cell stack 4 is arranged in the at least one extruded profile or at least one battery cell stack 4 is arranged in each extruded profile. Fig. 1 shows an extruded profile without a cover, in which a battery cell stack 4 is arranged. The cover can be connected to the extruded profile or formed as a single piece. In a preferred embodiment, a battery housing 4 is designed in the form of an extruded profile with at least one chamber, with at least one battery cell stack 4 being arranged in at least one chamber.

[0034] In the example of Fig.1, the battery cell stack 4 consists of eight battery cells 3. In principle, more or fewer battery cells 3 can be provided per battery cell stack 4, for example two or more battery cells 3, in particular approximately two to eight or more battery cells 3.

[0035] In a preferred embodiment, the battery cells 3 are clamped to one another and / or to the battery housing 2 on the other sides, which do not have a contact element 6, and / or are cast by a thermally conductive paste, so that essentially only the sides 5 with the contact elements 6 are available as degassing directions in the installation situation. List of reference symbols 1 battery 2 battery cases 3 battery cells 4 battery cell stacks 5 Page 6 Contact element 7 Edge 8 foam element 9 Predetermined breaking point 10 Opening 11 compressible element 12 Degassing device 13 Degassing opening QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 213 878 332 U

[0003]

Claims

[1] Battery (1) with a battery housing (2) and with battery cells (3) arranged therein, wherein the battery cells (3) are arranged as a battery cell stack (4), wherein the battery cells (3) are designed as pouch cells, wherein a pouch cell has a peripheral edge (7), wherein on at least one side (5) of the peripheral edge (7) of the pouch cell at least one contact element (6) is passed through the edge (7) and protrudes from the body of the pouch cell in order to serve for contacting the battery cell (3), wherein on the side (5) of the battery cell (3) on which at least one contact element (6) is arranged, a foam element (8) is arranged on the battery cell (3), which foam element covers the edge (7) of the battery cell (3). [2] Battery (1) according to claim 1, characterized by that the foam element (8) has a predetermined breaking point (9). [3] Battery (1) according to one of the preceding claims, characterized bythat the foam element (8) is designed such that one foam element (8) is arranged for each battery cell (3) or that one foam element (8) is arranged for a number of battery cells (3) or that one foam element (8) is arranged for a battery cell stack (4). [4] Battery (1) according to one of the preceding claims, characterized bythat the foam element (8) is designed in such a way that one foam element (8) is arranged for each battery cell (3), wherein the foam element (8) rests as a type of cap or lid on the edge (7) of the battery cell (3) or engages over the edge (7) of the battery cell (3), or that one foam element (8) is arranged for each number of battery cells (3), wherein the foam element (8) rests as a type of cap or lid on the edge (7) of the battery cells (3) or engages over the edge (7) of the battery cells (3), or that one foam element (8) is arranged for each battery cell stack (4), wherein the foam element (8) rests as a type of cap or lid on the edge (7) of the battery cells (3) of the battery cell stack (4) or engages over the edge (7) of the battery cell (3) of the battery cell stack (4). [5] Battery (1) according to one of the preceding claims, characterized bythat the foam element (8) is formed from a foam, in particular from a multi-component foam, which hardens in particular after liquid application. [6] Battery (1) according to one of the preceding claims, characterized by that the foam element (8) has at least one opening (10), in particular a slot, for the passage of a contact element (6), in particular at least two openings (10), in particular two slots, for the passage of two contact elements (6) of a battery cell (3). [7] Battery (1) according to one of the preceding claims, characterized by that the foam element (8) is larger in the direction perpendicular to the main surface area of the battery cell (3) than the thickness of the battery cell (3) in this direction. [8] Battery (1) according to one of the preceding claims, characterized bythat a compressible element (11), in particular a compressible surface element, is arranged between two battery cells (3), wherein the surface element is optionally arranged such that it touches the foam element (8). [9] Battery (1) according to one of the preceding claims, characterized by that the battery housing (2) is provided in the area adjacent to or opposite the side (5) of the battery cells (3) on which the contact elements (6) of the battery cells (3) and the at least one foam element (8) are arranged, a degassing device (12), in particular with at least one degassing opening (13). [10] Battery (1) according to one of the preceding claims, characterized by that the battery housing (2) consists of at least one extruded profile, wherein at least one battery cell stack (4) is arranged in the at least one extruded profile or at least one battery cell stack (4) is arranged in each extruded profile.

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