Housing cover for energy storage module and method for mounting an energy storage module

Abstract

Housing cover for energy storage module and method for mounting an energy storage module. The present invention relates to a housing cover for a housing (4) for an energy storage module (1), which is designed to receive an arrangement of a plurality of energy storage cells, preferably prismatic energy storage cells or pocket energy storage cells, preferably lithium-ion energy storage cells, electrically connected to each other by means of cell connectors (2), the cell connectors (2) being connected to each other by laser welding at contact points (303) using the terminals (302) of the respective energy storage cells (3). According to the invention, at least one welding window (410) is provided in the housing cover (402) in the region of a contact point (303). Figure to be published with the abstract: Fig. 2.

Description

Title of the invention: Housing cover for energy storage module and method for mounting an energy storage module

[0001] The present invention relates to a housing cover for a housing for an energy storage module, as well as a method for mounting an energy storage module comprising such a housing cover.

[0002] Energy storage is of crucial importance in the development of electrically powered means of transport, for example, electric vehicles. For this purpose, energy storage modules with high power and energy density are required. Energy storage modules can form an individual energy storage unit or several interconnected energy storage modules. Energy storage modules typically consist of a plurality of individual energy storage cells (for example, lithium-ion battery cells) that are electrically connected to one another. Energy storage modules generally require temperature control to ensure their operation within an optimized temperature range.Energy storage cells typically have a narrow operating temperature range (e.g., between +15°C and +45°C). The functional safety, lifespan, and cycle life of the energy storage cell, and therefore the functional safety of the entire energy storage system, depend on the cell remaining within this range. If the temperature exceeds a critical threshold, a thermal runaway can occur. During a thermal runaway, an unstoppable chain reaction is initiated. In this case, the temperature rises dramatically within milliseconds, and the energy stored in the energy storage cell is released abruptly. Temperatures of up to 400°C can thus occur.The contents of the energy storage unit are gaseous, and a fire can occur, which is difficult to extinguish by conventional means. The risk of thermal runaway begins at a certain temperature (e.g., 60°C) and is extremely critical above another temperature threshold (e.g., 100°C). Therefore, in energy storage units, particularly those for electric vehicles, an energy storage management system is used, which not only controls or regulates the charging and discharging behavior of the energy storage cells, but also takes measures to monitor and control the energy storage unit. Measures concerning temperature control and emergency management in the event of a thermal runaway are also taken into account. To ensure a controlled release of gases during a thermal runaway, gas-tight sealed energy storage cells are equipped with venting openings. These venting openings can, for example, be designed as rupture points which, at a predetermined internal pressure, allow gases to escape from inside the energy storage cell into the environment. The escaping gases may contain electrolytes that can react with water to form hydrofluoric acids. To reduce the risk to surrounding components and / or personnel, such gases must be released in a controlled and targeted manner.

[0003] For the electrical connection of energy storage cells, the energy storage modules have, as cell contacting elements, what are called cell connectors that electrically connect two or more poles of two or more energy storage cells, depending on the type of connection (series or parallel). In a series connection, for example, the anode of one energy storage cell is connected to the cathode of another energy storage cell. The energy storage modules may also have, as cell contacting elements, what are called module connectors that serve to electrically connect individual energy storage modules to one another.To monitor and regulate the state of charge of each energy storage cell, each cell connector can be electrically connected to the control and / or regulation electronics of the energy storage module. Therefore, the cell voltage of each individual energy storage cell can be measured, and the state of charge of the individual energy storage cell can be deduced from the cell voltage. Furthermore, sensors, such as temperature sensors, can be provided for monitoring the surface temperature of the energy storage cells; these sensors are connected to the control and / or regulation electronics. The control and / or regulation electronics are contained in a separate assembly in the preceding solutions.

[0004] In addition, for technical safety reasons, the cell connectors must be provided with contact protection so as to prevent accidental manual contact with the cell connectors.

[0005] A power supply device is known from EP 3 660 945 B1 in which hot gases exit from degassing openings in individual energy storage cells along a degassing surface. Individual energy storage units are vented in a targeted manner via a degassing channel. A circuit board is used for this purpose, positioned opposite the individual degassing openings and extending at intervals along the degassing surface. For protection against hot gases, the circuit board is equipped with a multi-layered thermal protection foil.

[0006] DE 10 2019211 907 A1 describes a battery module comprising a housing formed from plastic material, in which a fiber-reinforced element is arranged peripherally inside or outside the housing, the fiber-reinforced element being received in a housing of end plates. The fiber-reinforced element is to be cured by heat or UV radiation. A housing cover is screwed onto the upper side of the housing. The interior of the housing is hermetically sealed against fluids from the environment.

[0007] DE 10 2020 135 026 B3 discloses a battery comprising a plurality of cells connected to each other by means of a first electrical cell connector and a second electrical cell connector. The battery further has a battery inlet and a battery outlet for a thermoregulation fluid. In this case, the first and second electrical cell connectors are in direct contact with the thermoregulation fluid. Consequently, the thermoregulation fluid is electrically insulating, so that the cells are not discharged through the thermoregulation fluid.

[0008] The objective of the present invention is to provide a housing cover for an energy storage module housing, which makes it possible to simply complete an energy storage module in terms of production technique.

[0009] The above problem is solved by means of a housing cover for a housing for an energy storage module, which is intended to receive an arrangement of a plurality of energy storage cells, preferably prismatic energy storage cells or pocket energy storage cells, preferably lithium-ion energy storage cells, electrically connected to each other by means of cell connectors,

[0010] the cell connectors being connected to each other with the terminals of the respective energy storage cells by laser welding at points of contact, and

[0011] at least one welding window being provided in the housing cover in the region of a contact point.

[0012] By virtue of the invention, cell contacting elements, namely cell connectors, can be easily connected to each other by laser welding at contact points using the cell terminals of respective energy storage cells, since at least one welding window is provided in the housing cover for the passage of a laser beam through the welding window in the region of a contact point. The housing cover can thus serve as a cell contacting system. Therefore, it is possible, for the first time, to weld cell connectors to the terminals of the energy storage cells when the housing cover is already mounted. The housing cover can thus advantageously be pre-equipped with other components to form a prefabricated mounting unit. According to the invention, cell contacting elements, namely module connectors, can also be connected in the manner described to the terminal of the energy storage cell.

[0013] Advantageously, the housing cover itself provides protection against contact with the electrical contacts and thus performs a dual function. Preferably, the housing cover forms a contact barrier in the region of the respective contact point, preventing accidental contact with the point when the housing is closed. For this reason, no separate assembly steps are required to ensure contact protection. This significantly simplifies the production process of an energy storage module.

[0014] Preferably, at least one welding window is dimensioned in such a way that it is not possible to grasp through it with a human finger or with a corresponding testing finger.

[0015] By the fact that not only one but several welding windows are provided in the region of the respective contact point, it is possible to obtain on the one hand an effective contact by laser welding, and on the other hand, thanks to the possible reduction in the dimension of the several welding windows, it is possible to obtain improved protection against contact for a contact point compared with a single welding window of identical total passage area, i.e. corresponding.

[0016] With regard to protection against contact, it is particularly advantageous for the welding windows to be in the form of slots.

[0017] With regard to protection against contact, it is also particularly advantageous for the welding windows to be made so as to extend in a curved manner.

[0018] Because the welding windows form a narrowing through channel from the upper side towards the lower side of the housing cover, the laser beam reflected by the surface of the cell connector can exit upwards again through the welding window, without damaging any of the cover's constituent elements. the casing is not damaged by the reflected laser beam during the welding operation.

[0019] Preferably, the narrowing angle is defined according to the process, and is preferably at least 20°, particularly preferably at least 22.5°.

[0020] By having several welding windows arranged along a circular or oval path, it can be ensured that the forces caused by the welding are distributed regularly and that no significant stress peaks are produced.

[0021] Preferably, the welding windows have a width that ensures protection against contact (by a finger). Preferably, the width is less than 2 mm.

[0022] The welding windows can be arranged laterally in the housing cover, preferably on the outside relative to the degassing channel and / or the cooling channel. The respective degassing channel and / or cooling channel is located between rows of welding windows extending along the energy storage module.

[0023] According to another embodiment, the soldering windows can be arranged between a first stage or a first offset of the housing cover and the outer edge, considered in cross-section of the housing cover. Thanks to the first stage or the first offset, a storage space is created on the inner side of the housing cover, which storage space can be used to receive other functional components. This allows, for example, the respective soldering window to be arranged in the immediate vicinity of the cell connector or the module connector, even if a degassing channel or at least part thereof and / or at least one cooling channel are integrated into the housing cover.

[0024] Considered in cross-section of the housing cover, the welding windows can be arranged between a first stage or the first offset of the housing cover and the outer edge.

[0025] Considering the cross-section of the housing cover, an air gap can be provided between the upper side of the cell connectors and the opposite lower side of the welding window. This prevents damage to the lower side of the housing cover during the welding operation.

[0026] Preferably, support projections can be molded on the underside of the housing cover laterally to the weld windows, these projections resting on the cell connector. Thus, an air gap can be formed between the upper side of the cell connectors or module connectors and the opposite lower side of the case cover. In particular, a space or air gap is disposed between the upper side of the cell connectors and the opposite lower side of the soldering window, considered in cross-section of the case cover.

[0027] Preferably, the housing comprises a basic housing body made in particular as a molded part of plastic material, which basic housing forms an interior space in particular open on one side for receiving energy storage cells, in particular lithium-ion storage cells, as well as a housing cover made in particular as a molded part of plastic material, which closes the open side of the interior space.

[0028] Advantageously, the housing surrounds the arrangement of the energy storage cells, in particular by exerting a compressive stress on the arrangement of the energy storage cells. The housing may comprise a basic housing body, particularly made as a molded plastic part, which basic body forms an internal space for receiving the energy storage cells, and a housing cover, particularly made as a molded plastic part, which closes one open side of the internal space.

[0029] The invention further relates to a method for assembling an energy storage module comprising a housing as described above. According to the method of the invention, the cell connectors are connected to each other by laser welding at the contact points using the terminals of the respective energy storage cells, after the housing cover has been placed on the housing base filled with the energy storage cells. The laser beam for laser welding the cell connectors extends, in this case, through the respective welding window. This makes it possible to considerably simplify the manufacturing process of energy storage cells, since prefabricated mounting modules can be used, taking into account the housing cover.

[0030] The laser beam can be oriented perpendicularly to the cell connector during laser welding.

[0031] In addition, the laser beam can be moved in sections along a circular or oval path during laser welding, producing weld lines extending over a circular or oval path.

[0032] Before laser welding, the housing cover is positioned and / or fixed in a predetermined position relative to the housing base using retaining means integrated into the latter. Thus, the welding windows can be positioned or oriented precisely with respect to their respective contact points or welding positions before laser welding takes place. This can be achieved, for example, by having the housing cover, for instance during a The vertical drop onto the housing base body is snapped into place. This not only simplifies assembly but also ensures the necessary quality of laser welding of the cell connectors.

[0033] Advantageously, the housing cover and cell connectors can be provided as a prefabricated mounting unit.

[0034] The prefabricated assembly unit may further comprise the following functional parts:

[0035] at least one cooling channel, preferably two cooling channels, the at least one cooling channel or preferably two cooling channels being connected in particular in one piece with the cell connectors and / or in particular in one piece with the power socket or manufactured as an assembly; and / or

[0036] at least one degassing channel or at least constituent elements delimiting a degassing channel, and / or

[0037] projections as downward retaining elements for a printed circuit board and / or

[0038] a power outlet for the energy storage module, and / or

[0039] at least one, preferably a plurality of mounting tabs for attaching the energy storage module to a mounting substrate, and / or

[0040] snap-fit ​​means for ensuring a snap-fit ​​connection between the housing cover and the housing base body.

[0041] Appropriately, embodiments of the present invention are explained in more detail with the aid of figures. Recurring features are referenced only once for clarity. In the drawings:

[0042] [Fig. 1] illustrates a perspective representation of an example of an energy storage module comprising a housing cover according to the present invention;

[0043] [Fig.2] illustrates a simplified cross-sectional representation of the accumulation module energy of the [Fig.l];

[0044] [Fig.3] illustrates a perspective representation of the basic housing body of the housing of the embodiment according to [Fig.1];

[0045] [Fig.4] illustrates a perspective representation of the clamping band coated by injection into the base body of the housing according to [Fig.3];

[0046] [Fig. 5a] illustrates a top-down perspective representation of an arrangement of a cooling channel comprising several cell contacting elements according to the energy storage module of [Fig.1];

[0047] [Fig. 5b] illustrates a perspective representation from below of the arrangement according to the [Fig.5a];

[0048] [Fig.6] illustrates an enlarged cross-sectional representation of part of the lid of housing according to [Fig.l];

[0049] [Fig.7] illustrates a perspective representation of the cooling channel according to the [Fig.5a] before the introduction of the cell contacting elements;

[0050] [Fig.8] illustrates a perspective representation of a contacting element of cell configured as a cell connector according to a first example of implementation according to [Fig.1];

[0051] [Fig.9] illustrates a perspective representation of a contacting element of cell configured as a module connector according to a first example of implementation according to [Fig.1];

[0052] [Fig. 10] illustrates a cross-sectional view of a second example of an embodiment of a cell contacting element;

[0053] [Fig. 11] illustrates a cross-sectional view of the arrangement according to [Fig.5a] with a cell contacting element according to the second embodiment according to [Fig.10];

[0054] [Fig. 12] illustrates an enlarged perspective representation of a part of the housing cover according to the energy storage module of [Fig.1] in the welding window region;

[0055] [Fig. 13] illustrates several welding windows, arranged along a circular path, from a point of contact in top view;

[0056] [Fig. 14] illustrates an enlarged representation of a portion of the housing cover in the region of the welding windows in cross-sectional representation and

[0057] [Fig. 15] illustrates a representation of the shape of the laser cone for laser welding through the welding windows of [Fig. 13].

[0058] Figure 1 illustrates an example of a housing 4 for an energy storage module 1 for prismatic energy storage cells or so-called pocket energy storage cells. For example, in this case, these are lithium-ion energy storage cells. Such energy storage modules are used, for example, in electric vehicles, such as automobiles. Several energy storage modules 1 that are electrically connected to each other are generally used in an electric vehicle.

[0059] The housing 4 comprises, according to the invention, a housing base body 401 and a housing cover 402 fixed to the upper side of the housing base body 401. The housing base body 401 and the housing cover 402 are designed as molded plastic parts (injection molded parts), in order to ensure the lowest possible weight of the energy storage module 1.

[0060] The housing 4 of the energy storage module 1 has an elongated parallelepiped shape. Along the housing cover 402, a plurality of connecting means are provided on both sides of the housing cover 402. These serve to mechanically connect the housing cover 402 to the housing base body 401. Preferably, the connecting means can be snap-fit ​​connections 408. In addition, a plurality of welding windows 410, the significance of which is described below, are also located on both sides of the housing cover 402.

[0061] In the front region of the energy storage module 1, a printed circuit board 7 protrudes, through which signals from sensors for a battery management system (BMS) (not shown in [Fig. 1]) can be supplied. Within the energy storage module 1 are a venting channel 5 and two cooling channels 6, which are located respectively below the housing cover 402. The direction of venting in a critical situation where, due to overpressure, gases escape from inside an energy storage cell, is represented by way of example by the two arrows shown in [Fig. 1].

[0062] A passage (not shown in the figure) between the two laterally located cooling channels 6 may be provided in the front region of the energy storage module 1. The lateral cooling channels 6 are connected, respectively, via a connecting channel 612, to a cooling channel of another energy storage module (not shown) or to a cooling system (also not shown). Using the cooling channel 6, a cooling fluid can be supplied to the energy storage cell 1 from the cooling system.

[0063] Through openings 411 are formed on the housing base 401, projecting laterally. These openings contain perforated tubular reinforcements for attaching the energy storage module 1 to a base plate (not shown in [Fig. 1]) within the housing base 401. The finished energy storage module 1 can thus be mounted onto a base plate, for example, using a screw connection. The reference numeral 223 designates a power outlet on a module connector 220.

[0064] Figure 2 illustrates a cross-sectional view through the internal structure of the energy storage module 1 according to Figure 1. Inside the housing 4 of the energy storage module 1 are a plurality of energy storage cells 3 which are equipped with respective terminals 302 in the region of the upper side shown in Figure 2. On the upper side of the terminal 302 are the respective cell contacting elements in the form of connectors. cell 2 which connect together energy storage cells 3 neighboring an energy storage module 1.

[0065] The venting openings 301 shown in [Fig. 2] are provided in the energy storage cells 3. These are specially formed openings which, if an overpressure is exceeded within the energy storage cell 3, open automatically and allow hot gas to escape. To prevent the hot gas from reaching the interior of the passenger compartment, a venting channel 5 is provided, through which the escaping hot gas can be discharged in a targeted manner in two directions, for example as shown by the arrows in [Fig. 1]. In addition, at the end of an energy storage module 1 there may be a main collection channel (not shown in the drawings) through which the hot gas can be discharged in a targeted manner to the exterior side of the vehicle.

[0066] Preferably, the energy storage module 1 or its housing cover 402 forms a fluid-tight interface with such a main collection channel. Provided that two energy storage modules 1 are coupled to each other, the hot gas can also be guided through the degassing channel 5 of the adjacent energy storage module 1 to a main collection channel. The degassing openings 301 of the individual energy storage cells 3 form, on the upper side of the arrangement of the energy storage cells 3, a degassing surface that is opposite the housing cover 402 at a distance from it, such that the cavity between the housing cover 402 and the degassing surface of the individual energy storage cells 3 forms the degassing channel 5.By completing the housing cover 402 on the housing base body 401, which is open on one side and filled with energy storage cells 3, the degassing channel 5 can also be easily formed at the same time.

[0067] The housing cover 402 can, by design, be easily fitted with a gasket 407 made of a heat-resistant and / or fire-resistant material in the region of the degassing channel 5. The gasket 407 can, as appropriate, extend to the degassing surface of the energy storage cells 3. The gasket 407 can either be bonded to the housing cover 402 or attached to it by welding. Alternatively, the housing cover 402 can also be a multi-component injection-molded part, in which the gasket 407 is introduced as an injection-molded component immediately during the manufacturing process, or a corresponding insert piece is injection-coated.

[0068] A cooling channel 6 is located laterally relative to the degassing channel 5. The cooling channel 6 may have a U-shaped configuration and penetrates, with its open side facing upwards, into a The lower recess 406 is grooved in the housing cover 402. The corresponding cooling channel 6 cools the cell connectors 2 using a cooling fluid contained within it and supplied via a connecting channel 612. Therefore, the housing cover 402 can also be designed with corresponding cooling channels 6 as a prefabricated component. When mounting the housing cover, the cooling channels 6 are advantageously also integrated into the energy storage module 1.

[0069] The respective cell connector 2 extends horizontally into the region of the respective cooling channel 6, such that the cooling fluid exerts a cooling effect on the portion of the cell connector 2 extending into the region of the cooling channel 6, and thus on the cell connector 2 itself. The cell connector 2 can, in this case, as shown in [Fig. 2], be arranged to extend into the lower wall of the U-shaped cooling channel 6. Alternatively, it can also extend directly into the cavity of the cooling channel 6 through which the cooling fluid flows (see [Fig. 11]).

[0070] Below the respective cooling channel 6 is a printed circuit board 7 through which signals for a battery management system (BMS) (not shown in [Fig. 1]) can be supplied. Through the printed circuit board 7, signals from sensors (not shown in the figures) (e.g., temperature sensors, gas sensors, pressure sensors) can, for example, be supplied to the battery management system (BMS) or to a control unit. The printed circuit board 7 protrudes slightly at the narrow front side of the energy storage module 1 as shown in [Fig. 1], so that data or signal sampling can take place there. The printed circuit board 7 is loosely inserted and is held in position by lower protrusions 608 of the cooling channel 6.The printed circuit board 7 can preferably be a flexible printed circuit board (i.e., a so-called flexible board).

[0071] The power socket 223 of the energy storage module 1 further protrudes as part of the module connector 220 ([Fig. 9]) on the narrow front side of the energy storage module 1, as can be seen in [Fig. 1]. The power socket 223 is located between a mounting tab 420 and the through opening 411. Via the power socket 223, the energy storage module 1 can be connected to other energy storage modules not shown or to an electrical consumer not shown, for example, an electric motor of an electric vehicle.

[0072] The housing cover 402 has, according to [Fig. 2], a first stage 403 laterally relative to the degassing channel 5, such that the housing cover 402 is located laterally relative to the region of the cooling channel 6 with the respective cell connector 2 in the region of the terminal 302. A rib 405, which together with the first stage 403 forms a groove-shaped recess 406 for receiving the cooling channel 6, is located offset inwards relative to the first stage 403. The two ribs 405 also form a bearing surface for the lateral regions of the packing 407 and delimit the degassing channel 5 laterally.

[0073] Furthermore, the housing cover 402 may have a second stage 404 laterally relative to the first stage 403, so that the housing cover 402 laterally grips around the outer region of the respective cell connector 2. In addition, a vertically extending projection 409 and a vertically overlapping peripheral edge 418 may be provided in the edge region of the housing cover 402, which position or center the housing cover 402 in its position relative to the housing base body 401.

[0074] The construction, described above, of the energy storage module 1 guarantees a considerable simplification of the assembly in terms of production technique compared with the energy storage modules known until now.

[0075] Figure 3 illustrates the structure of the housing base body 401 as a separate part of the invention. The housing base body 401 is a housing base body 401 made as a molded part of synthetic material and having a substantially rectangular shape. A clamping band 8 extending inside the housing base body 401 comprises a plurality of fibers (not shown in Figure 3), which serves to absorb clamping forces from the energy storage cells 3. The clamping band 8 is injection-molded into the housing base body 401. The injection molding of the clamping band 8 results in the complete removal of individual parts for its retention. The clamping band 8 prevents the housing base body 401 from expanding during cell respiration (known as swelling).

[0076] The clamping band 8 extends between a side wall 417 and internal retaining ribs 413, 414 of the housing base body 401, which are located along the entire periphery of the housing base body 401. The clamping band 8 may, in this instance, be located in a recess 412 inside the side wall 417 according to [Fig. 2]. The retaining ribs 413, 414 extend from an upper side of the housing base body 401 to its lower side and are provided on all four sides. The retaining ribs 413, 414 determine the exact position at which The energy storage cells 3 are inserted. Each energy storage cell 3 rests, for example, against a lateral retaining rib 413.

[0077] The retaining ribs 414 located in the front lateral region are wedge-shaped. A loose clamping wedge 415 can, after the energy storage cells are inserted into the housing base body 401, be pressed along the wedge-shaped retaining ribs 414 to clamp the arrangement of the energy storage cells 3 to the housing base body 401, thus ensuring that the clamping wedge 415 is tightened in the z-direction or towards the upper side of the housing. In the lateral region are snap hooks 416 as part of the connecting means or the snap-fit ​​connection 408 described earlier. The housing base body 401 and the housing cover 402 are made of a thermoplastic material.

[0078] Figure 4 illustrates the clamping band 8 as a prefabricated component in which fibers (not shown) in the form of continuous fibers are wound several times around the periphery of the clamping band 8. For example, the clamping band 8 can be designed as a pre-fixed, frame-type, injection-coated component containing the fibers. For this purpose, the clamping band 8 is manufactured, for example, using a tape-laying process or a winding process, for example, as a unidirectional band.

[0079] Figures 5a and 5b illustrate an arrangement 9 comprising several cell contacting elements configured as cell connectors 2, a cell contacting element configured as a module connector 220, and the cooling channel 6. The arrangement 9 forms part of the energy storage module 1 and is located inside the housing cover 402. The cell connector 2 serves to electrically connect two energy storage cells (not shown in Figures 5a and 5b) via a first contact surface 212 and a second contact surface 213. The module connector 220 serves to electrically connect an energy storage cell (not shown in Figures 5a and 5b) located at one front end of the energy storage module 1 via a contact surface 222. The module connector 220 comprises the 223 power outlet.

[0080] Fig. 6 illustrates an enlarged cross-sectional representation of a portion of the housing cover 402 according to Fig. 1 with arrangement 9, in which the cell contacting element 2, 220 is embedded or incorporated within a lower wall 607 of the cooling channel 6.

[0081] Figures 5a to 6 show that the cell contacting elements 2, 220 are connected to, or incorporated into, the cooling channel 6 by means of a melting region 613. The cell contacting elements 2, 220 They comprise, respectively, a first side 215, 225 (not shown in Figures 5a and 5b) and a second side 216, 226, only the first side 215, 225 of the cell contacting elements 2, 220 being connected to the cooling channel 6 at least in some regions or being incorporated into it at least in some regions. In this case, the first side 215, 225 of the cell contacting elements 2, 220 is incorporated into a lower wall 607 of the cooling channel 6 according to the first embodiment of the arrangement 9, see [Fig. 6]. In this case, the cell contacting elements 2, 220 do not penetrate the interior of the cooling channel 6. In this case, the cell contacting elements 2, 220 do not need to be protected against a corrosive and / or electrically conductive cooling fluid.

[0082] Alternatively, the first side 215, 225 of the cell contacting elements 2, 220 can also penetrate through a first side wall 605 of the cooling channel 6 into the interior of the cooling channel 6, see [Fig. 11].

[0083] Advantageously, the cooling channel 6 and the cell contacting elements 2, 220 can thus be connected so as to form a common assembly which can be mounted as a prefabricated assembly in an assembly step respectively on the housing cover 402, in particular glued at junction points 609, see [Fig.6] or 11.

[0084] Figures 5a to 7 show the first side wall 605, a second side wall 604, and the lower wall 607 of the cooling channel 6. In the upper region, the cooling channel 6 has an opening 606 that extends along the entire length of the cooling channel 6. In this case, the cooling channel 6 has a U-shaped cross-section open upwards. Alternatively, the cooling channel 6 may include, instead of the upper opening 606, an upper wall, so that the cooling channel 6 has a closed quadrangular cross-section.

[0085] The cooling channel 6 has several projections 608 on its lower wall 607, as shown in Figures 5b and 6. These projections 608 are positioned below the cell contact elements 2, 220, and 220, respectively. The printed circuit board 7 is positioned below the projections 608. The printed circuit board 7 can be pressed onto a substrate by means of the projections 608 and thus held in position. This has the advantage that, through the assembly of the components, the cooling channel 6 secures the printed circuit board 7 in its position, thus eliminating another assembly step.

[0086] As can be seen in Figures 5a to 7, the cooling channel 6 further comprises a first front opening 601 and a second front opening 602. The first opening 601 and the second opening 602 respectively have a Circular flow cross-section. Through the first opening 601 and the second opening 602, the cooling channel 6 can be connected via the connecting channel 612, see [Fig.1], to a cooling system not shown.

[0087] The cooling channel 6 is preferably bonded in a fluid-tight manner to the housing cover 402 at the junction points 609. In this case, if the cooling channel 6 has a U-shaped profile, the housing cover 402 simultaneously forms the upper wall of the cooling channel 6 and closes the opening 606. For this purpose, two junction points 609 preferably extend along the entire longitudinal length of the cooling channel 6. The junction points 609 are located in the region of the opening 606 at the first side wall 605 and the second side wall 604. Consequently, the first side wall 605 and the second side wall 604 are bonded to the housing cover 402 at their respective front sides.Therefore, the bonded seal, preferably fluid-tight, at the junction points 609 ensures that no cooling fluid enters the interior of the housing 4 from the cooling channel 6.

[0088] Figure 8 illustrates a perspective view of the cell contacting element configured as a cell connector 2. The cell connector 2 comprises an electrically conductive basic body 211 made of a flat material or as a stamped part. The basic body 211 includes the first contact surface 212 for electrically connecting a terminal 302 of the energy storage cell 3 and the second contact surface 213 for electrically connecting a terminal (not shown in the figures) of a second energy storage cell (not shown in the figures). In this case, the first and second contact surfaces 212, 213 are connected to the terminal 302 of the first energy storage cell 3 or to the terminal of the second energy storage cell, in particular welded to it.The first side 215 of the cell connector 2 includes in this case a region connecting the contact surfaces 212, 213.

[0089] The first and second contact surfaces 212, 213 are separated from each other by a recess 219. Thus, the current flow is shifted towards the first side 215. Since the first side 215 can be disposed in the cooling channel 6, the cell connector 2 can be cooled particularly efficiently.

[0090] The cell contacting element, implemented as a module connector 220, comprises, according to [Fig. 9], an electrically conductive base body 221. The base body 221 includes the contact surface 222 for electrically connecting a terminal (not shown in the figures) of an energy storage cell (not shown in the figures) preferably located at a front end of the Energy storage module 1. The contact surface 222 is connected to the terminal, in particular soldered to it. In addition, the module connector 220 includes the power socket 223 with a through hole 229 for fixing the power socket 223, for example by means of a screw connection, to the housing 4. The first side 225 connects in this case to the contact surface 222.

[0091] According to a first embodiment, the basic bodies 211, 221 of the cell contacting elements 2, 220 are bare, in particular uncoated. In this case, the electrically conductive basic body 211, 221 of the respective cell contacting element 2, 220 can be in direct contact with a wall of the cooling channel 6. Furthermore, if a non-electrically conductive cooling fluid is used, the electrically conductive basic body 211, 221 of the respective cell contacting element 2, 220 can enter the cooling channel 6. Thus, an effective cooling effect is achieved.

[0092] Figure 10 illustrates a cross-section of the contacting elements of cell 2, 220 according to a second embodiment. According to the second embodiment, a partial region 214, 224 of the contacting elements of cell 2, 220 or of the respective base body 213, 223 is covered with a planar coating 217, 227, the partial region 214, 224 extending over the entire first side 215, 225 of the contacting elements of cell 2, 220.

[0093] Figure 11 illustrates a cross-sectional view of the cell contacting element 2, 220 coated according to the second embodiment according to [Fig. 10] in an arrangement 9. In this case, the coated partial region 214, 224 of the cell contacting element 2, 220 enters through the first side wall 605 into the interior of the cooling channel 6. The cooling fluid therefore flows around the coated partial region 214, 224 of the cell contacting element 2, 220. Thus, direct cooling of the cell contacting element 2, 220 can be ensured.

[0094] It is particularly advantageous here for the coating 217, 227 to be a thermally conductive, electrically insulating material, in particular a thermally conductive, electrically insulating plastic. Thus, the cell contacting element 2, 220 is insulated by the coating 217, 227, although an electrically conductive cooling fluid can also be used. Preferably, the coating 217, 227 also has adhesion-enhancing properties, so that the respective cell contacting elements 2, 220 can adhere directly to the cooling channel 6 or its wall without an additional adhesive.

[0095] The coating 217, 227 in particular has a thickness 218, 228 of less than 0.5 mm, preferably less than 0.4 mm, particularly preferably less than 0.3 mm.

[0096] The cell contacting elements 2, 220 are permanently connected to each other via the cooling channel 6, without additional fastening means, so as to form a single-piece assembly. In this case, it may be a process in which the wall of the cooling channel 6 is brought to a plastic state in certain regions by targeted heating, so that the cell contacting element 2, 220 is pushed through the wall or an opening in the wall. The heating may, for example, be carried out by means of a laser beam or by means of ultrasonic vibrations.

[0097] During the ultrasonic heating of the cooling channel wall 6, an ultrasonic vibration is introduced into at least one partial region of the cooling channel 6, heating it to its melting point. Appropriately, this partial region is located on the first side wall 605 or on the bottom wall 607. In this case, at least one partial region is positioned specifically at the locations where a cell contacting element 2, 220 is to be positioned. Thus, only the partial region of the cooling channel 6 is heated and melted, the region at which a cell contacting element 2, 220 is to be connected to the cooling channel 6. In the case of multiple cell contacting elements 2, 220, several partial regions of the cooling channel 6 are specifically provided, into which the ultrasonic vibration is introduced.

[0098] Appropriately, ultrasonic vibration is introduced into the partial region of the cooling channel 6 by means of cell contacting elements 2, 220, so that only the contact region of the cooling channel 6 is melted, through which a cell contacting element 2, 220 must be introduced into the cooling channel 6.

[0099] Alternatively, ultrasonic vibration can be introduced into the cooling channel 6 by means of an ultrasonic vibration transmitter, for example a sonotrode, in particular at predetermined positions for the cell contacting elements 2, 220.

[0100] The cell contacting elements 2, 220 are introduced into the cooling channel 6 after the respective partial region of the cooling channel 6 has been heated. In this case, the first heated side wall 605 is, for example, pierced by the cell contacting element 2, 220. Alternatively, the cell contacting element 2, 220 is pushed into the heated lower wall 607 of the cooling channel 6. The molten partial region thus surrounds the corresponding cell contacting element 2, 220 by fusion. Next, the introduction of the ultrasonic vibration is completed and the partial region of the cooling channel 6 is solidified. Thus, the fusion region 613 extending around the respective cell contacting elements 2, 220. The fusion region 613 ensures a fluid-tight connection, so that no cooling fluid can penetrate the interior of the housing 4 from the cooling channel 6 at the fusion region 613.

[0101] Alternatively, a recess is provided in the cooling channel 6 at the predetermined position for the respective cell contacting element 2, 220, either in the first side wall 605 or in the lower wall 607. The corresponding cell contacting element 2, 220 can be pressed into this recess. In this case, only the edge regions of the recesses are melted. The melted edge regions of the recesses then fuse around the cell contacting elements 2, 220, which are pushed into the respective recesses, and form the fusion region 613 after solidification. The cell contacting elements 2, 220 preferably enter the cooling channel 6 through the first side wall 605.

[0102] Alternatively, in the region of the first side wall 605, instead of a recess, a through opening dimensioned slightly smaller in comparison with the respective cell contacting element 2, 220 may be provided, the edge region of which is melted in the manner described above and in this case the cell contacting elements 2, 220 also extend through the first side wall 605 into the interior of the cooling channel 6.

[0103] As an alternative to the ultrasonic process, the cell contacting elements 2, 220 can be injection coated by the cooling channel 6 as an injection molded part during the manufacture of the cooling channel 6. Thanks to the injection coating of the cell contacting elements 2, 220, a fluid-tight connection is formed between the cell contacting elements 2, 220 and the cooling channel 6.

[0104] Figure 12 illustrates a portion of the housing cover 402 of the energy storage module 1 in the region of the weld windows 410 in an enlarged representation. The weld windows in the housing cover 402 represent an original contribution of the invention. In the embodiment illustrated in Figure 12, several (for example, four) weld windows 410 are provided for each contact point 303. The weld windows 410 are arranged on each side of the housing cover 402 between the first stage 403 or the first offset and the outer edge region of the housing cover 402 in the longitudinal direction of the energy storage module 1, preferably at a constant distance from each other. For example, the weld windows (410) are arranged in the cover of housing (402) laterally along a degassing channel (5) and / or laterally along at least one cooling channel (6).

[0105] Figure 12 also shows the second stage 404 or second offset, the shaped portion ensuring the snap-fit ​​connection 408, and the mounting tab 420. The mounting tab 420 is located on the housing cover 402 at the position corresponding to the through opening 411 on the housing base 401. The energy storage module 1 can be attached to a mounting surface not shown in the figures, for example, by means of a screw (not shown), using the mounting tab 420. In the example of an energy storage module 1 illustrated in Figure 4, a total of four mounting tabs 420 are provided in the front region of the housing cover 402.

[0106] The welding windows 410 are arranged in the housing cover 402 respectively in a row laterally along the degassing channel 5 as well as laterally with respect to the degassing channels 6.

[0107] As can be seen in [Fig. 13], the individual welding windows 410 preferably have a slot-like shape, are made so as to extend in a curved manner and are located along a circular path 425. The width of the welding windows 410 is preferably less than 2 mm.

[0108] The welding windows 410 form a through channel narrowing from the upper side towards the lower side of the housing cover 402, as shown in [Fig. 14]. Thus, after the entry of the laser beam, the laser beam reflected by the surface of the cell connector can exit upwards again through the welding window 410, without any constituent elements of the housing cover 402 being damaged by the reflected laser beam during the welding operation.

[0109] Preferably, the angle of narrowing considered relative to the normal is at least 20°, preferably at least 22.5°. The narrowing takes into account the fact that the laser beam, when passing perpendicularly through the welding window 410, is reflected on the surface of the cell connector 2, which is represented by [Fig. 15]. The local representation illustrates the conical shape of the reflected laser beam 10 as well as the respective displacement region 101 of the laser beam 10 along a circular path for implementing laser welding in the case of the welding window configuration according to [Fig. 13]. [Fig. 15] illustrates the predefined reflection of the laser beam 10 on the reflective surface of the cell connector 2. For purely visual purposes, this reflection is shown rotated 180°, i.e., reversed in [Fig. 15].

[0110] As an alternative to a circular path, several welding windows can also be arranged along an oval path at a point of contact 303. Thanks to the arrangement of several welding windows along a circular path or an oval trajectory, we obtain that the forces caused by the welding are present in a regularly distributed manner and that no significant stress peaks are produced.

[0111] As can be seen in [Fig. 14], an air gap or air blade 423 is located between the upper side of the cell connectors 2 and the opposite lower side of the weld window 410. This air gap prevents damage to the lower side of the housing cover 402 during the welding operation. To ensure the air gap or air blade 423, support projections 424 are molded onto the lower side of the housing cover 402 laterally to the weld windows 410. These projections rest on the cell connector (not shown in [Fig. 14]). Thus, the air gap 423 can be formed between the upper side of the cell connectors and the opposite lower side of the housing cover 402.

[0112] The measure of inserting welding windows 410 into the housing cover 402 allows for an advantageous method of mounting the energy storage module 1, the cell connectors 2 being connected to each other by laser welding via the terminals 302 of the respective energy storage cells 3 to the contact points 303, after the housing cover 402 has been placed on the housing base body 401 filled with the energy storage cells 3, the laser beam 10 extending through the respective welding window 410 for laser welding. The laser beam 10 is oriented perpendicularly to the cell connectors 2 or to the module connectors 220.

[0113] The snap-fit ​​connection 408 between the housing cover 402 and the housing base body 401 allows for easy handling of the housing cover 402 on the housing base body 401 and at the same time a pre-setting of the welding windows 410 with respect to the relevant contact points 303.

[0114] The above-mentioned procedure makes it possible to produce the 402 housing cover and cell connectors in the form of a prefabricated mounting unit.

[0115] Furthermore, the prefabricated mounting unit, which includes the housing cover 402 and the cell connectors 2 or the module connectors 220, may, in addition to functional components, include, for example, the following components: at least one cooling channel 6, preferably two cooling channels 6, which may be connected, in particular in a single piece, to the cell connectors 2, as shown in Figures 5a and 5b, and preferably in a single piece to the module connector 220. Furthermore, the venting channel 5, or at least some components lining the venting channel, for example the lining 407, may form part of the prefabricated mounting unit. Using the module connector 220, the power outlet 223 of the The energy storage module 1 can also be part of the prefabricated mounting unit, as can the mounting tabs 420 used to attach the energy storage module 1 to an underlying mounting surface (not shown). Furthermore, retaining means, such as snap-fit ​​means to ensure a snap-fit ​​connection between the housing cover 402 and the housing base body 401, can be provided on the housing cover 402.

[0116] Advantageously, the housing cover (402) and the cell connectors (2), preferably the housing cover (402), the cell connectors (2) and the module connectors (220), are provided as a prefabricated mounting unit.

[0117] In conclusion, the use of welding windows offers considerable advantages in terms of implementing the assembly sequence of an energy storage module 1. The housing cover according to the invention can advantageously also be used without a housing, for example as protection against the contacts of a cell contacting system.

[0118] The present invention therefore guarantees a considerable contribution to the technical field in question.

[0119] The elements, parts, components, pieces, indications and objects shown in the attached figures are referenced as follows:

[0120] 1 energy storage module

[0121] 2 cell connector

[0122] 211 basic body

[0123] 212 contact surface

[0124] 213 contact surface

[0125] 214 partial region

[0126] 215 first side

[0127] 216 second side

[0128] 217 coating

[0129] 218 thickness

[0130] 219 recess

[0131] 220 module connector

[0132] 221 basic body

[0133] 222 contact surface

[0134] 223 power outlet

[0135] 224 partial region

[0136] 225 first side

[0137] 226 second side

[0138] 227 coating

[0139] 228 thickness

[0140] 229 through hole

[0141] 3 energy storage cell

[0142] 301 degassing opening

[0143] 302 terminal

[0144] 303 contact point

[0145] 4 box

[0146] 401 base body of housing

[0147] 402 case cover

[0148] 403 first floor

[0149] 404 Second floor

[0150] 405 rib

[0151] 406 obviously

[0152] 407 trim

[0153] 408 snap-fit ​​connection

[0154] 409 protrusion

[0155] 410 welding window

[0156] 411 through opening

[0157] 412 obviously

[0158] 413 retaining rib

[0159] 414 retaining rib

[0160] 415 clamping wedge

[0161] 416 snap hook

[0162] 417 side wall

[0163] 418 edge

[0164] 419 wall bevel

[0165] 420 fixing bracket

[0166] 421 central part

[0167] 422 rib

[0168] 423 air space

[0169] 424 support projection

[0170] 425 circular trajectory

[0171] 5 degassing channel

[0172] 6 cooling channel

[0173] 601 opening

[0174] 602 opening

[0175] 604 side

[0176] 605 side

[0177] 606 opening

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189] 607 base 608 projection 609 junction point 612 connecting channel 613 fusion region 7 printed circuit board 8 clamping band 9 arrangement 10 laser beam 101 laser beam displacement region B welding window width Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, particularly with regard to the construction of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. Housing cover for a housing (4) for an energy storage module (1), which is provided for receiving an arrangement of a plurality of energy storage cells (3), preferably prismatic energy storage cells or energy storage pouch cells, preferably lithium-ion energy storage cells, electrically connected to one another via cell connectors (2), wherein the cell connectors (2) are connected to one another with the terminals (302) of the respective energy storage cells (3) by laser welding at contact points (303), and at least one welding window (410) is provided in the housing cover (402) in the region of a contact point (303).

2. Housing cover according to claim 1, characterized in that the housing cover (402) forms, in the region of the respective contact point (303), a contact protection so as to prevent accidental contact with the contact point when the housing (4) is closed.

3. Housing cover according to claim 1 or 2, characterized in that several welding windows (410) are provided in the region of the respective contact point (303).

4. Housing cover according to at least one of the preceding claims, characterized in that the welding windows (410) are slot-shaped.

5. Housing cover according to at least one of the preceding claims, characterized in that the welding windows (410) are designed to extend in a curved manner.

6. Housing cover according to at least one of the preceding claims, characterized in that the welding windows (410) form a through channel narrowing from the upper side towards the lower side of the housing cover (402).

7. Housing cover according to claim 6, characterized in that the taper angle is defined depending on the process, and is preferably at least 20°, particularly preferably at least 22.5°.

8. Housing cover according to at least one of the preceding claims, characterized in that several welding windows (410) are arranged along a circular path or an oval path.

9. Housing cover according to claim 6, characterized in that the welding windows (410) have a width B ensuring protection against contact.

10. Housing cover according to at least one of the preceding claims, characterized in that the welding windows (410) are arranged in the housing cover (402) laterally along a degassing channel (5) and / or laterally along at least one cooling channel (6).

11. Housing cover according to at least one of the preceding claims, characterized in that the welding windows (410) are arranged between a first stage (403) of the housing cover (402) and the outer edge, considered in cross-section of the housing cover (402).

12. Housing cover according to at least one of the preceding claims, characterized in that a gap or air gap (423) is arranged between the upper side of the cell connectors (2) and the opposite lower side of the welding window (410), considered in cross-section of the housing cover (402).

13. Housing cover according to at least one of the preceding claims, characterized in that support projections (424) are provided on the underside of the housing cover (402) laterally relative to the soldering windows (410), which projections rest on the cell connector (2).

14. Housing cover according to at least one of the preceding claims, characterized in that the housing (4) surrounds the arrangement of the energy storage cells (3), in particular by forming a compressive stress on the arrangement of the energy storage cells, the housing (4) comprising a housing base body (401) in particular made as a plastic molding, which base body forms an interior space for receiving the energy storage cells (3), and a housing cover (402) in particular made as a plastic molding, which closes an open side of the interior space.

15. Method for mounting an energy storage module (1) having a housing cover according to at least one of the preceding claims, characterized in that the cell connectors (2) are connected to each other with the terminals (302) of the respective energy storage cells (3) by laser welding at the contact points (303), after the housing cover (402) has been placed on the housing base body (401) filled with the energy storage cells (3), the laser beam (10) extending through the respective welding window (410) for laser welding.

16. Method according to claim 15, characterized in that the laser beam (10) is oriented perpendicular to the cell connector (2).

17. Method according to claim 16, characterized in that the laser beam (10) is moved in sections along a circular path or an oval path.

18. Method according to at least one of claims 15 to 17, characterized in that the housing cover (402), when lowered vertically onto the housing base body (401), is snapped onto the latter.

19. Method according to at least one of claims 15 to 18, characterized in that the housing cover (402) and the cell connectors (2), preferably the housing cover (402), the cell connectors (2) as well as the module connectors (220), are provided as a prefabricated assembly unit.

20. Method according to claim 19, characterized in that the prefabricated assembly unit further comprises the following elements: at least one cooling channel (6), preferably two cooling channels (6), the at least one cooling channel (6) or the preferably two cooling channels being connected in particular in one piece with the cell connectors (2) and / or in particular in one piece with the socket (223); and / or at least one degassing channel (5) or at least constituent elements delimiting a degassing channel (5), and / or projections (608) as downward holding elements for a printed circuit board (7) and / or a socket (223) of the energy storage module (1), and / or at least one, preferably a plurality of fixing lugs (420) for fixing the energy storage module (1) to a fixing substrate, and / or latching means for ensuring a latching connection between the housing cover (402) and the housing base body (401).

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