Method for manufacturing a battery, battery, motor vehicle

Abstract

A method for manufacturing a battery (100) for a motor vehicle (200) is proposed, wherein battery cells (1) are arranged on a cell carrier (2), the cell carrier (2) being inserted into a battery housing (3), the cell carrier (3) having a groove (4) comprising an inlet (4.1) and an outlet (4.2) located next to the inlet (4.1), the groove (4) extending from the inlet (4.1) to the outlet (4.2) along the sides of the cell carrier (2) towards the battery housing (3), and a sealing agent being introduced into the inlet (4.1) until the sealing agent emerges at the outlet (4.2). Furthermore, a battery (100) and a motor vehicle (200) are proposed.

Description

[0001] The present invention relates to a method for manufacturing a motor vehicle battery. Furthermore, the present invention relates to a motor vehicle battery and a motor vehicle.

[0002] Electric and hybrid vehicles have an electrified powertrain. The main components of such an electrified powertrain are the electric motor for traction, the battery for supplying the electric motor with electrical energy, and the power electronics, which supplies energy from the battery to the electric motor as needed. The battery of the vehicle, as defined in the present invention, is the so-called traction battery, i.e., a high-voltage battery for supplying the powertrain.

[0003] Current developments in electrified powertrains focus not only on increasing efficiency but also on ensuring durability and simplifying the manufacturing processes of the powertrain components.

[0004] A battery typically consists of multiple battery cells. These cells are arranged within a battery casing, where they are temperature-controlled, particularly cooled, and secured. The cells are usually secured by pressing them into the casing. This creates a tight seal between the cells and the casing, preventing them from shifting during operation, especially during acceleration, deceleration, or steering maneuvers.

[0005] During battery operation, the battery cells regularly undergo changes in size. Experts refer to this as swelling or breathing. The compression of the battery cells within the battery casing leaves little room for such changes.

[0006] A traction battery for a motor vehicle is known from German patent application DE 10 2022 133 863 A1. The traction battery has a battery housing in which battery cells are arranged. The battery housing has venting openings for degassing the battery cells.

[0007] It is therefore an object of the present invention to provide a method for manufacturing a battery, a motor vehicle battery and a motor vehicle which do not have the aforementioned disadvantages of the prior art, but enable simple manufacturing of the battery in conjunction with an advantageous arrangement of the battery cells which allows a change in the size of the battery cells and at the same time a high degree of safety against leakage of a coolant from the battery housing.

[0008] This problem is solved by a method for manufacturing a motor vehicle battery according to claim 1. Furthermore, this problem is solved by a motor vehicle battery according to claim 9 and by a motor vehicle according to claim 10.

[0009] The method according to the invention is a method for manufacturing a motor vehicle battery, in particular a traction battery for a motor vehicle. To manufacture the battery, battery cells are arranged on a cell carrier. The cell carrier preferably has ribs between which the battery cells can be inserted. The ribs advantageously stabilize the battery cells in their position during the manufacturing process. The cell carrier with the battery cells is inserted into a battery housing. A groove is provided on the cell carrier, which faces the battery housing. The groove has an inlet on one side of the cell carrier and an outlet directly next to the inlet. From the inlet, the groove extends along the sides of the cell carrier to the outlet. In other words, the groove is practically a circumferential groove.To seal and fix the cell carrier in the battery housing, a sealant is injected into the groove at the inlet until it emerges at the outlet. This applies the sealant all the way around, bonding the cell carrier to the battery housing.

[0010] Advantageous embodiments and further developments of the invention can be found in the dependent claims and in the description with reference to the drawings.

[0011] According to a preferred embodiment of the present invention, the cell carrier is bonded to the battery housing with the sealant. This achieves a high degree of security against movement of the cell carrier and the batteries along the XY plane of the vehicle.

[0012] A particularly preferred embodiment of the present invention is one in which the cell carrier has venting openings and the battery housing has further venting openings. The venting openings and the further venting openings are arranged one above the other. This advantageously makes it possible to selectively degas the battery cells in the event of thermal runaway. The groove is arranged such that it surrounds the venting openings. This advantageously prevents coolant from escaping the battery through the further venting openings.

[0013] According to a further preferred embodiment of the present invention, a metal foil, in particular a metal adhesive tape, is affixed to the outside of the battery housing, at least over the additional venting openings. This prevents dirt from entering the battery through the additional venting openings. Furthermore, the metal foil ensures compliance with EMC requirements. In addition, the application of the metal adhesive tape is very simple, which facilitates manufacturing.

[0014] According to a further preferred embodiment of the present invention, the battery cells are potted on the cell carrier before being inserted into the battery housing. Potting results in at least two positive effects. The battery cells are fixed to the cell carrier. Thus, the battery cells are securely seated on the cell carrier and therefore securely within the battery housing. Furthermore, the potting compound seals the cell carrier towards the battery housing, preventing coolant from escaping through the venting openings. The potting of the battery cells inserted into the cell carrier preferably includes a waiting period during which the potting compound can at least partially harden. This ensures that the battery cells are securely held for the subsequent manufacturing process.

[0015] To prevent potting compound from leaking out during the encapsulation of the battery cells, a raised edge is preferably provided on the cell carrier. This significantly simplifies the battery manufacturing process. Especially with viscous potting compounds, the cell carrier can be easily filled. The potting compound then spreads evenly across the cell carrier between the battery cells and assumes its final position.

[0016] According to a further preferred embodiment of the present invention, an upper cell carrier is arranged on the battery cells before they are inserted into the battery housing. The upper cell carrier is preferably bonded to the battery cells. In particular, it is provided that the upper cell carrier is bonded to the battery cells at specific points. The upper cell carrier can, for example, accommodate cables, electronics, interfaces, or mountings. Bonding the upper cell carrier to the battery cells ensures that the cell carrier is fixed to the battery cells, especially during battery manufacturing, and that no displacement of the upper cell carrier occurs relative to the battery cells. It is sufficient to bond the upper cell carrier only at specific points, thus saving adhesive.

[0017] According to a particularly preferred embodiment of the present invention, the cell carrier and the upper cell carrier are arranged such that less than 25%, and in particular less than 10%, of the side surfaces of the respective battery cells are in direct contact with the cell carrier and the upper cell carrier. It has been found that this is sufficient for securely holding the battery cells. At the same time, this allows the battery cells to expand more easily during battery operation. This advantageously improves the battery's ability to tolerate cell breathing, in particular. Furthermore, this provides the advantage of making more surface area of ​​the battery cells available for direct application of coolant. This significantly improves the efficiency of battery cell cooling.

[0018] A further object of the present invention for solving the problem formulated at the outset is a battery for a motor vehicle. The battery comprises battery cells which are arranged on a cell carrier. The cell carrier is arranged on a battery housing. The cell carrier has a groove in which a sealant is arranged, which bonds the cell carrier to the battery housing and seals the interior of the battery. Preferably, the battery is manufactured using the method according to the invention.

[0019] All details, features, and advantages previously disclosed in connection with the method according to the invention also relate to the battery according to the invention.

[0020] Another object of the present invention for solving the problem formulated at the outset is a motor vehicle which has a battery according to the invention.

[0021] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept. Fig. Figure 1 schematically illustrates a battery according to an exemplary embodiment of the present invention in a sectional view. Fig. Figure 2 schematically illustrates a detail of a battery according to an exemplary embodiment of the present invention. Fig. Figure 3 schematically illustrates a detail of a battery according to an exemplary embodiment of the present invention. Fig. Figure 4 schematically illustrates a detail of a battery according to an exemplary embodiment of the present invention in a sectional view. Fig. Figure 5 schematically illustrates a detail of a battery according to an exemplary embodiment of the present invention in a sectional view. Fig. Figure 6 schematically illustrates a battery according to an exemplary embodiment of the present invention in a sectional view. Fig. Figure 7 schematically illustrates a motor vehicle according to an exemplary embodiment of the present invention.

[0022] Fig. Figure 1 schematically illustrates a battery 100 of a motor vehicle 200 (see Fig. 7) in a sectional view. Battery 100 has a plurality of battery cells 1 (see Fig. 3, Fig. 4, Fig. 5, Fig. 6) shown here, but not labelled for the sake of clarity, are further elements of the battery 100, such as cell electronics or interfaces.

[0023] The battery cells 1 are also arranged on a cell carrier 2. Ribs 8 on the cell carrier 2 ensure that the battery cells 1 are securely positioned on the cell carrier 2 during the manufacturing of the battery 100.

[0024] After the battery cells 1 are placed on the cell carrier 2, the battery cells 1 are encased in a potting compound 10 (for clarity only shown in ). Fig. (shown in Figure 6) is potted. The potting compound 10 hardens and fixes the battery cells 1 to the cell carrier 2. To prevent the potting compound 10 from unintentionally leaking out of the cell carrier 2 before hardening, the cell carrier 2 has a raised edge 7. The potting compound 10 can thus be easily inserted into the cell carrier 2 without the risk of it running out laterally.

[0025] After the battery cells 1 are potted onto the cell carrier 2, an upper cell carrier 5 is placed on the battery cells 1 (see Fig. 3) The upper cell carrier 5 is fixed to the battery cells 1 using a mounting adhesive.

[0026] The battery cells 1 on the cell carrier 2 are then inserted into a battery housing 3 together with the upper cell carrier 5. The battery housing 3 is made of aluminum.

[0027] The cell carrier 2 is provided with venting openings 2.1. When the cell carrier 2 is inserted into the battery housing 3, the venting openings 2.1 are located directly above further venting openings 3.1 of the battery housing 3. In the event of thermal runaway, the venting openings 2.1 and the further venting openings 3.1 enable controlled degassing of the battery cells 1.

[0028] To prevent dirt from entering the further venting openings 3.1, these are sealed with a metal adhesive tape 6, for example, an aluminum adhesive tape. Firstly, sealing with the metal adhesive tape 6 can be very easily integrated into the manufacturing process. Secondly, sealing with the metal adhesive tape 6 allows for electromagnetic shielding in addition to protection against contamination, thus enabling compliance with EMC requirements. In the event of thermal runaway, the pressure of the escaping gases will detach or tear the metal adhesive tape 6.

[0029] The battery cells 1 are directly supplied with a coolant (not shown) within the battery housing 3. To ensure efficient flow of the coolant along the battery cells 1 and thus effective cooling, coolant channels 9 are provided on the sides of the battery cells 1.

[0030] In addition to fixing the battery cells 1 to the cell carrier 2, the potting compound 10 also seals the venting openings 2.1. This prevents coolant from escaping through the venting openings 2.1.

[0031] Once the battery cells 1, along with the cell carrier 2 and the upper cell carrier 5, are inserted into the battery housing 3, the cell carrier 2 is fixed to the battery housing 3. A groove 4 is provided on the underside of the cell carrier 2 for this purpose (see figure). Fig. 5 and Fig. 6) The groove 4 has an inlet 4.1 on the end face of the cell carrier 2 and an outlet 4.2, which is located directly next to the inlet 4.1. The groove 4 runs from the inlet 4.1 along the sides of the cell carrier 2 to the outlet 4.2 and thus encloses the venting openings 2.1.

[0032] To fix the cell carrier 2 in the battery housing 3, a sealant is injected into the inlet 4.1. This is continued until the sealant emerges from the outlet 4.2. This ensures that sealant is applied along the entire length of the groove 4. The sealant then bonds the cell carrier 2 to the battery housing 3. This adhesive bond eliminates the need to press the battery cells 1 into the battery housing 3.

[0033] Furthermore, the sealant seals the area between the cell carrier 2 and the battery housing 3 around the perimeter, preventing coolant from flowing laterally between the cell carrier 2 and the battery housing 3 into the further venting openings 3.1. This is in Fig. 6 clearly visible.

[0034] The illustrated arrangement of battery housing 3, cell carrier 2, battery cells 1, upper cell carrier 5, and groove 4 with the sealant applied therein is particularly advantageous with regard to allowing the battery cells 1 to expand freely during operation of the battery 100. The battery cells 1 are fixed only by the potting compound 10 in the cell carrier 2 and the adhesive points on the upper cell carrier 5. The cell carriers 2 and 5 cover a maximum of 10% of the lateral surface of the battery cells 1. This advantageously enables cell breathing. Reference symbol list 1 battery cell 2 cell carriers 2.1 Venting opening 3 battery cases 3.1 Additional venting opening 4 groove 4.1 Admission 4.2 Outlet 5 upper cell carrier 6 metal adhesive tapes 7 raised edge 8 ribs 9 Coolant routing 10 potting compound 100 batteries 200 motor vehicles

Claims

Method for manufacturing a battery (100) of a motor vehicle (200), wherein battery cells (1) are arranged on a cell carrier (2), wherein the cell carrier (2) is inserted into a battery housing (3), wherein the cell carrier (2) has a groove (4), wherein the groove (4) has an inlet (4.1) and an outlet (4.2) arranged next to the inlet (4.1), wherein the groove (4) is arranged extending from the inlet (4.1) to the outlet (4.2) towards the battery housing (3) along the sides of the cell carrier (2), wherein a sealing agent is introduced into the inlet (4.1) until the sealing agent emerges at the outlet (4.2). Method according to claim 1, characterized in that the cell carrier (2) is bonded to the battery housing (3) with the sealant. Method according to one of the preceding claims, characterized in that the cell carrier (2) has venting openings (2.1) and the battery housing (3) has further venting openings (3.1), wherein the venting openings (2.1) and the further venting openings (3.1) are arranged one above the other. Method according to claim 3, characterized in that a metal foil, in particular a metal adhesive tape (6), is applied to the outside of the battery housing (3) at least over the further venting openings. Method according to one of the preceding claims, characterized in that the battery cells (1) are potted on the cell carrier (2) before being inserted into the battery housing (3). Method according to claim 5, characterized in that the escape of potting compound (10) during potting is prevented by a raised edge (7) of the cell carrier (2). Method according to one of the preceding claims, characterized in that an upper cell carrier (5) is arranged on the battery cells (1) before insertion into the battery housing (3), wherein the upper cell carrier (5) is preferably bonded to the battery cells (1), wherein the upper cell carrier (5) is particularly bonded to the battery cells (1) at specific points. Method according to claim 7, characterized in that the cell carrier (2) and the upper cell carrier (5) are arranged such that less than 25% and in particular less than 10% of the side surfaces of the respective battery cells (1) are in direct contact with the cell carrier (2) and the upper cell carrier (5). Battery (100) for a motor vehicle (200), characterized in that the battery (100) comprises battery cells (1) which are arranged on a cell carrier (2), wherein the cell carrier (2) is arranged on a battery housing (3), wherein the cell carrier (2) has a groove (4) in which a sealing agent is arranged which bonds the cell carrier (2) to the battery housing (3) and seals an interior of the battery (100), wherein the battery (100) is preferably manufactured using a method according to one of the preceding claims. Motor vehicle (200) comprising a battery (100) according to claim 9.

Images