Housing cover for energy storage module and corresponding energy storage module

Abstract

Housing cover for energy storage module and corresponding energy storage module The present invention relates to a housing cover for a housing (4) for an energy storage module (1), which is intended to receive an arrangement of a plurality of energy storage cells (3), electrically connected to each other by means of cell connectors (2), the energy storage cells (3) forming a degassing surface having degassing openings (301) arranged along the degassing surface, which serve, in the event of an overpressure occurring in a critical situation in the energy storage cell (3) concerned, to allow gases to escape in a controlled manner from the interior of the energy storage cell (3) through the degassing opening (301).According to the invention, the housing cover (402) and the degassing surface form a degassing channel (5) extending towards at least one end of the housing cover (402), preferably towards both ends of the housing cover (402). Figure to be published with the abstract: Fig. 2.

Description

Title of the invention: Housing cover for energy storage module and corresponding energy storage module

[0001] The present invention relates to a housing cover for a housing of an energy storage module, as well as to a corresponding energy storage module.

[0002] The energy accumulator 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 energy accumulator individually or alternatively from several interconnected energy storage modules. The energy storage modules usually consist of a plurality of individual energy storage cells (for example lithium-ion battery cells) which are electrically connected to each other. The energy storage modules generally require temperature management in order to ensure their operation within an optimized temperature range.Energy storage cells usually have a narrow operating temperature range (e.g. between +15°C and +45°C). The functional safety, service life, and cycling resistance of the energy storage cell, and thus also the functional safety of the entire energy storage system, depend on the energy storage cell not leaving this range. If the temperature exceeds a critical threshold, a so-called thermal runaway can occur. In thermal runaway, a chain reaction that cannot be stopped is initiated. In this case, the temperature rises extremely within milliseconds, and the energy stored in the energy storage cell is released abruptly. Temperatures of up to 400°C can occur.The contents of the energy storage cell are gaseous and a fire occurs, which is difficult to extinguish by conventional means. The risk of thermal runaway begins from a certain temperature (e.g. 60 °C) and is extremely critical from another temperature threshold (e.g. 100 °C). Therefore, in energy storage cells, in particular energy storage cells for electric vehicles, an energy storage management system is used, with the help of which not only the charging and discharging behavior of the energy storage cells is controlled or regulated, but also measures in this regard. which concerns temperature management as well as emergency situation management in the event of a thermal runaway are also taken. In order to ensure a targeted escape of gases in the event of a thermal runaway, gas-tight sealed energy storage cells have venting openings. The venting openings can, for example, be designed as rupture points which, from a certain internal pressure, allow gases to escape from the interior of the energy storage cell into the environment. The escaping gases may contain electrolytes which can react with water to form hydrofluoric acids. In order to reduce the risk to surrounding components and / or people, such gases must be evacuated in a controlled and targeted manner.

[0003] For the electrical connection of the energy storage cells, the energy storage modules have, as cell contacting elements, so-called cell connectors which electrically connect two or more poles of two or more energy storage cells to each other depending on the type of connection (in series or in parallel). In a series connection, for example, the anode of one energy storage cell is respectively connected to the cathode of another energy storage cell. The energy storage modules may also have, as cell contacting elements, so-called module connectors which serve to electrically connect individual energy storage modules to each other.In order to be able 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. As a result, 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 derived from the cell voltage. Furthermore, sensors, for example temperature sensors, can be provided for monitoring the surface temperature of the energy storage cells, which sensors are connected to the control and / or regulation electronics. The control and / or regulation electronics are located in an independent assembly in the above solutions.

[0004] EP 3 660 945 B1 discloses a power supply device in which, along a degassing surface of individual energy storage cells, hot gases emerging from degassing openings in the individual energy storage cells are discharged in a targeted manner via a degassing channel. For this purpose, a circuit board is used which is arranged opposite the individual degassing openings and so as to extend at a distance of these along the degassing surface. For protection against hot gases, the circuit board is provided with a multi-layer thermal protection foil.

[0005] DE 10 2019 211 907 A1 describes a battery module having a housing formed from plastic, in which a fiber-reinforced element is arranged peripherally inside or outside the housing, the fiber-reinforced element being received in an end plate receptacle. 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 sealed fluid-tight from the environment.

[0006] DE 10 2020 135 026 B3 discloses a battery comprising a plurality of cells which are connected to each other via a first electrical cell connector and a second electrical cell connector. The battery further has a battery inlet and a battery outlet for a temperature control fluid. In this case, the first and second electrical cell connectors are in direct contact with the temperature control fluid. Therefore, the temperature control fluid is electrically insulating, so that the cells are not discharged via the temperature control fluid.

[0007] The aim of the present invention is to provide a housing cover for an energy storage module having a degassing channel or an energy storage module equipped with a corresponding housing cover, with the aid of which housing cover a simplified manufacture or completion in terms of production technology is possible.

[0008] The above problem is solved by means of a housing cover for an energy storage module, which is provided for receiving an arrangement of a plurality of energy storage cells, preferably prismatic energy storage cells or energy storage pouch cells, preferably lithium-ion energy storage cells, electrically connected to one another via cell connectors, the energy storage cells forming a venting surface provided with venting openings arranged along the venting surface, which serve, in the event of an overpressure occurring in a critical situation in the energy storage cell concerned, to allow gases to escape in a controlled manner from the interior of the energy storage cell via the venting opening, and

[0009] the housing cover forming, by its side facing the energy storage cells, a degassing channel.

[0010] Thus, according to the invention, the housing cover, on its side facing the energy storage cells, forms with the degassing surface a degassing channel extending in the direction of at least one end of the housing cover, preferably in the direction of both ends of the housing cover. Thus, it is possible to simplify the construction as well as the completion considerably, since the housing cover can already be shaped in such a way that it forms part of the degassing channel. The housing cover can in this case also serve as a cell contacting system. Furthermore, the housing cover can thus advantageously be pre-equipped with other components.When attaching the housing cover to the lower housing part, other functional components can also be mounted at the same time, e.g. cooling lines, cell connectors and / or protective fittings for the vent channel. This means that an energy storage module with a vent channel can be produced much faster and at a much lower cost than conventional designs.

[0011] Preferably, the housing cover has an elongated shape and the degassing channel extends along the longitudinal direction of the housing cover. The degassing channel preferably extends in an oriented manner along the entire housing cover or the entire housing from one of its end sides to its opposite end side. Thus, the escaping gases can be guided in a targeted manner to the end sides of the energy storage module.

[0012] By forming an interface, in particular a fluid-tight interface, to a main degassing channel connected to the energy storage module or to an adjacent energy storage module at at least one end of the housing cover, preferably at both ends of the housing cover, hot gases can be efficiently discharged without them being able to reach, for example, the passenger compartment or the interior of the vehicle.

[0013] The invention makes it possible, by shaping the housing cover, to make certain arrangements for functional parts. This is particularly evident in the context of the degassing channel. According to a suitable embodiment of the present invention, the housing cover may comprise, at its inner wall delimiting the degassing channel, a lining which is in particular temperature-resistant and / or fire-resistant. The lining may be a layer of heat-resistant and / or non-flammable material.

[0014] The trim may be an insert made in particular in the form of a profile. The latter may preferably be glued or welded onto the housing cover.

[0015] Alternatively, the housing cover and gasket may be part of a multi-component injection molded part.

[0016] Furthermore, the inner side of the housing cover may have a groove-shaped recess, preferably extending laterally along the degassing channel, which recess determines the position of a cooling channel or each cooling channel. For example, a cooling channel can be inserted into the groove.

[0017] By means of the invention, the housing cover is produced in the form of a structural element which must be simply prefabricated and provided with additional functions, which structural element still simply has to be mounted.

[0018] Due to the fact that the housing cover has spaced apart ribs extending in the direction of the degassing surface, which ribs delimit the degassing channel laterally, the recess for the degassing channel as well as the respective groove for the cooling channel can be fixed in their respective position in a structurally simple manner.

[0019] Furthermore, the housing cover may have a respective first step or tier on each side, so that the housing cover is located in its respective outer region in the immediate vicinity of the connection terminals of the energy storage cells, or rests on the cell connectors (2) in its respective outer region. Thus, on the one hand, the arrangement of energy storage cells is securely surrounded and, on the other hand, openings may be provided in the housing cover in this region, which openings allow attachment of the respective cell connectors to the associated connection terminals of the individual energy storage cells. In the same way, module connectors may also be attached.

[0020] Furthermore, the housing cover may have a respective second step or tier on each side, so that the housing cover encloses the cell connectors (on the outer side) in its outer region and rests in particular on the upper side of the arrangement of the energy storage cells.

[0021] Furthermore, a circumferential projection on the housing cover can be formed thereon in this region, which bears against the upper inner edge of the housing base body and thus centers the housing cover and the housing base body relative to each other. Thus, a simple completion in terms of production technology is made possible.

[0022] Furthermore, at least one mechanical connecting means, preferably several mechanical connecting means, is or are provided for fixing the housing cover to the housing base body. This or these means is (are) provided along the longitudinal side of the housing base body as well as the housing cover, preferably positioned on both sides of the degassing channel, for connecting the housing base body and the housing cover. Thus, a simple completion of the prefabricated housing cover with the housing base body is made possible. It is particularly advantageous if the at least one, preferably several mechanical connecting means, are a snap-in connection or snap-in connections.

[0023] The construction according to the invention also allows at least one rigid or flexible electrical conductor or conductive track to be arranged between the housing cover and the arrangement of the energy storage cells laterally to the degassing channel, preferably on both sides of the degassing channel. Preferably, this may be an individual wire, a cable harness, an FPC (flexible printed circuit), an FFC (flat flexible cable), a PCB (printed circuit board) and the like. Sensor signals from sensors located inside the housing can be guided via the printed circuit board. The signals guided via the printed circuit board can thus be provided for a battery management system (BMS) located outside the housing.

[0024] Preferably, the printed circuit board is located on the lower side of the cooling channel. Thus, the cooling channel can contribute to a positional fixing of the printed circuit board inside the energy storage module when the housing cover is attached, for example by the fact that the cooling channel or a projection arranged on the lower side thereof presses on the upper side of the printed circuit board. Advantageously, the printed circuit board can in this case be loosely inserted between the lower projection of the cooling channel and the upper side of the energy storage cells. Thus, the completion can be considerably simplified.

[0025] Preferably, the housing comprises a housing base body, in particular made as a plastic molding, which base body forms an interior space open on one side for receiving the energy storage cells, in particular lithium-ion storage cells, and a housing cover, in particular also made as a plastic molding, which closes the open side of the interior space.

[0026] The invention further relates to an energy storage module comprising a plurality of energy storage cells, preferably prismatic energy storage cells or energy storage pouch cells, preferably lithium-ion energy storage cells, as well as a housing cover as described above.

[0027] Suitably, embodiments of the present invention are explained in more detail with the aid of figures. Recurring features are not provided with a reference number only once for reasons of clarity. In the drawings:

[0028] [Fig. 1] illustrates a perspective representation of an exemplary energy storage module comprising a housing cover according to the present invention;

[0029] [Fig.2] illustrates a simplified cross-sectional representation of the accumulation module of energy of [Fig.l];

[0030] [Fig.3] illustrates a perspective representation of the basic housing body of the housing of the embodiment according to [Fig.l];

[0031] [Fig.4] illustrates a perspective representation of the clamping band coated by injection into the basic housing body according to [Fig.3];

[0032] [Fig.5a] illustrates a perspective representation from above of an arrangement of a cooling channel comprising several cell contacting elements according to the energy accumulation module of [Fig.l];

[0033] [Fig.5b] illustrates a perspective representation from below of the arrangement according to the [Fig.5a] ;

[0034] [Fig.6] illustrates an enlarged sectional representation of a portion of the cover of housing according to [Fig.l];

[0035] [Fig.7] illustrates a perspective representation of the cooling channel according to the [Fig.5a] before the introduction of the cell contacting elements;

[0036] [Fig.8] illustrates a perspective representation of a cell contacting element configured as a cell connector according to a first exemplary embodiment according to [Fig.l];

[0037] [Fig.9] illustrates a perspective representation of a contacting element of cell configured in the form of a module connector according to a first exemplary embodiment according to [Fig.l];

[0038] [Fig. 10] illustrates a sectional view of a second exemplary embodiment of a cell contacting element;

[0039] [Fig. 11] illustrates a sectional view of the arrangement according to [Fig.5a] with a cell contacting element according to the second embodiment example according to [Fig.10];

[0040] [Fig. 12] illustrates an enlarged perspective representation of a portion of the housing cover according to the energy storage module of [Fig.l] in the region of the welding window;

[0041] [Fig. 13] illustrates several welding windows, arranged along a circular path, from a contact point in top view;

[0042] [Fig. 14] illustrates an enlarged representation of a portion of the housing cover in the region of the welding windows in sectional representation and

[0043] [Fig. 15] illustrates a representation of the shape of the laser cone for laser welding through the welding windows of [Fig. 13].

[0044] [Fig. 1] illustrates an example of a housing 4 for an energy storage module 1 for prismatic energy storage cells or so-called pouch energy storage cells. For example, these are lithium-ion energy storage cells. Such energy storage modules are used, for example, for electrically powered vehicles, for example automobiles. Several energy storage modules 1 that are electrically connected to each other are generally used in an electrically powered vehicle.

[0045] 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 plastic molded parts (injection molded parts) in order to ensure the lowest possible weight of the energy storage module 1.

[0046] 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 may be a snap-in connection 408. Furthermore, a plurality of welding windows 410, the meaning of which is described below, are also provided on both sides of the housing cover 402.

[0047] In the front region of the energy storage module 1 protrudes a printed circuit board 7 with the aid of which signals from sensors for a battery management system (BMS) (not shown in [Fig. 1]) can be provided. In the energy storage module 1 there is a degassing channel 5 as well as two cooling channels 6 which are arranged respectively below the housing cover 402. The direction of degassing in the context of a critical situation in which, due to an occurring overpressure, gases escape from the interior of an energy storage cell, is shown by way of example by the two arrows shown in [Fig. 1].

[0048] A passage (not shown in the figure) between the two laterally located cooling channels 6 can be provided in the front region of the energy storage module 1. The lateral cooling channels 6 are respectively connected via a connecting channel 612 to a cooling channel of another energy storage module (not shown) or to a cooling system (which is also not shown). With the aid of the cooling channel 6, a cooling fluid cooling can be fed to the energy storage cell 1 from the cooling system.

[0049] On the housing base body 401, through openings 411 are formed in a laterally projecting manner, in which tubular perforated reinforcements are located for fixing the energy storage module 1 to a base plate (not shown in [Fig. 1]) in the housing base body 401. Thus, the finished energy storage module 1 can be mounted on a base plate, for example, by means of a screw connection. Reference numeral 223 denotes a socket of a module connector 220.

[0050] [Fig.2] illustrates a sectional view through the internal structure of the module energy storage module 1 according to [Fig. 1]. Inside the housing 4 of the energy storage module 1 there are a plurality of energy storage cells 3 which are equipped with respective terminals 302 in the region of the upper side shown in [Fig. 2]. On the upper side of the terminal 302 there are the respective cell contacting elements in the form of cell connectors 2 which connect neighboring energy storage cells 3 of an energy storage module 1 to each other.

[0051] The degassing openings 301 shown in [Fig. 2] are provided in the energy storage cells 3. These are specially shaped openings which, if an excess pressure established in the interior of the energy storage cell 3 is exceeded, open automatically and allow a hot gas to escape. In order to prevent the hot gas from reaching the interior of the passenger compartment, a degassing channel 5 is provided, via 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]. Furthermore, 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 outside of the vehicle.

[0052] Preferably, the energy storage module 1 or its housing cover 402 forms a fluid-tight interface with respect to such a main collection channel. Provided that two energy storage modules 1 are coupled to each other, the hot gas can also be guided via 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 which faces the housing cover 402 at a distance therefrom, so that the cavity between the housing cover 402 and the degassing surface of the individual energy storage cells 3 forms the main collection channel. degassing 5. By completing the housing cover 402 on the housing base body 401 open on one side and filled with the energy storage cells 3, the degassing channel 5 can therefore also be formed in a simple manner at the same time.

[0053] The housing cover 402 can, by construction, be provided in a simple manner with a lining 407 made of a heat-resistant and / or fire-resistant material in the region of the degassing channel 5. The lining 407 can, suitably, extend to the degassing surface of the energy storage cells 3. The lining 407 can either be glued into the housing cover 402 or fixed thereto by welding. Alternatively, the housing cover 402 can also be a multi-component injection-molded part, into which the lining 407 is introduced as an injection-molded component immediately during the manufacturing process or a corresponding insert part is injection-molded.

[0054] A cooling channel 6 is located laterally relative to the degassing channel 5. The cooling channel 6 can have a U-shaped configuration and, with its open side positioned upwards, penetrates into a lower groove-shaped recess 406 of the housing cover 402. The respective cooling channel 6 serves to cool the cell connectors 2 using a coolant located therein and supplied via a connecting channel 612 as a supply line. 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 simultaneously into the energy storage module 1.

[0055] The respective cell connector 2 extends horizontally in the region of the respective cooling channel 6, so that the cooling fluid exerts a cooling effect on the part of the cell connector 2 extending in the region of the cooling channel 6 and thus on the cell connector 2 as such. The cell connector 2 can in this case, as shown in [Fig. 2], be arranged so that it extends 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]).

[0056] Below the respective cooling channel 6 there is a printed circuit board 7 by means of which signals for a battery management system (BMS) (not shown in [Fig.l]) can be provided. Via 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 provided for the battery management system (BMS) or for a control unit. The printed circuit board 7 projects slightly at the narrow front side of the energy storage module 1 according to [Fig. 1], so that data or signal sampling can take place there. The printed circuit board 7 is inserted loosely and is held in position by lower projections 608 of the cooling channel 6. The printed circuit board 7 may preferably be a flexible printed circuit board (i.e. a so-called flex board).

[0057] The socket 223 of the energy storage module 1 further projects as part of the module connector 220 ([Fig. 9]) at the narrow front side of the energy storage module 1, as can be seen in [Fig. 1]. The socket 223 is located between a fastening lug 420 and the through opening 411. Via the 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.

[0058] The housing cover 402 has, according to [Fig. 2], laterally relative to the degassing channel 5, a first stage or step 403 respectively, so 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-like recess 406 for receiving the cooling channel 6, is located offset inwardly relative to the first stage 403. The two ribs 405 furthermore also form a bearing surface for the lateral regions of the lining 407 and delimit the degassing channel 5 laterally.

[0059] Furthermore, the housing cover 402 may have a second step or step 404 laterally relative to the first step 403, so that the housing cover 402 engages laterally around the outer region of the respective cell connector 2. Furthermore, a vertically extending projection 409 as well as a laterally vertically overlapping circumferential 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.

[0060] The above-described construction of the energy storage module 1 ensures a considerable simplification of the assembly in terms of production technology compared to the energy storage modules known until now.

[0061] [Fig. 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. Inside the housing base body 401 extends a clamping strip 8 comprising a plurality of fibers (not shown in [Fig. 3]), which serves to absorb clamping forces of the energy storage cells 3. The clamping strip 8 is injection-molded into the housing base body 401. The injection-molding of the clamping strip 8 causes a complete removal of individual parts for holding it. The clamping strip 8 prevents the housing base body 401 from being expanded during cell respiration (so-called swelling).

[0062] The clamping strip 8 extends between a side wall 417 and inner 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 strip 8 can in this case be located in an inner recess 412 of 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 bears, for example, against a lateral retaining rib 413.

[0063] The retaining ribs 414 in the front side region are designed in a wedge-shaped manner. A loose clamping wedge 415 can, after the energy storage cells have been inserted into the housing base body 401, be pressed along the wedge-shaped retaining ribs 414 for clamping between the arrangement of energy storage cells 3 and the housing base body 401 and thus ensures clamping of the clamping wedge 415 in the z-direction or in the direction of the upper housing side. In the side region there are latch hooks 416 as part of the connecting means or the latch connection 408 described initially. The housing base body 401 and the housing cover 402 are made of a thermoplastic plastic.

[0064] [Fig. 4] illustrates the clamping strip 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 strip 8. For example, the clamping strip 8 can be designed as a pre-fixed, frame-like, injection-coated component containing the fibers. For this purpose, the clamping strip 8 is manufactured, for example, using a tape laying process or using a winding process, for example as a unidirectional strip.

[0065] 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 as well as the cooling channel 6. The arrangement 9 is part of the energy storage module 1 and is arranged inside the cover of housing 402. The cell connector 2 serves for electrical contacting of two energy storage cells (not shown in FIGS. 5a and 5b) via a first contact surface 212 and a second contact surface 213. The module connector 220 serves for electrical contacting of an energy storage cell (not shown in FIGS. 5a and 5b) arranged at a front end of the energy storage module 1 via a contact surface 222. The module connector 220 comprises the socket 223.

[0066] [Fig. 6] illustrates an enlarged sectional representation of a portion of the housing cover 402 according to [Fig. 1] with the arrangement 9, in which the cell contacting element 2, 220 is embedded or incorporated within a bottom wall 607 of the cooling channel 6.

[0067] It can be seen in Figures 5a to 6 that the cell contacting elements 2, 220 are connected to the cooling channel 6, or are incorporated therein, via a fusion region 613. The cell contacting elements 2, 220 respectively comprise a first side 215, 225 (not shown in Figures 5a and 5b) as well as 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 therein at least in some regions. In this case, the first side 215, 225 of the cell contacting elements 2, 220 is incorporated in a bottom 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 into the interior of the cooling channel 6.In this case, the cell contacting elements 2, 220 must not be protected against a corrosive and / or electrically conductive cooling fluid.

[0068] Alternatively, the first side 215, 225 of the cell contacting elements 2, 220 may also penetrate through a first side wall 605 of the cooling channel 6 into the interior of the cooling channel 6, see [Fig. 11].

[0069] 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.

[0070] Figures 5a to 7 show the first side wall 605, a second side wall 604, and the bottom wall 607 of the cooling channel 6. In the upper region, the cooling channel 6 has an opening 606 that extends along the entire cooling channel 6. The cooling channel 6 in this case has a U-shaped cross-section open upwards. Alternatively, the cooling channel 6 may comprise, instead of the upper opening 606, an upper wall, so that the cooling channel 6 has a closed quadrangular cross-section.

[0071] The cooling channel 6 has, on the bottom wall 607, several projections 608, see figures 5b and 6. These projections 608 are positioned respectively below the cell contacting elements 2, 220. The printed circuit board 7 is arranged below the projections 608. The printed circuit board 7 can be pressed onto a substrate by means of the projections 608 and thus be held in position. This has the advantage that, by assembling the components, the cooling channel 6 fixes the printed circuit board 7 in its position and thus a further assembly step can be saved.

[0072] 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. Via the first opening 601 and the second opening 602, the cooling channel 6 can be connected via the connection channel 612, see [Fig.l], to a cooling system not shown.

[0073] The cooling channel 6 is preferably bonded in a fluid-tight manner to the housing cover 402 at the joining points 609. In this case, in the case of a U-shaped profile of the cooling channel 6, the housing cover 402 simultaneously forms the upper wall of the cooling channel 6 and closes the opening 606. For this purpose, two joining points 609 preferably extend along the entire longitudinal extent of the cooling channel 6. The joining points 609 are arranged in the region of the opening 606 at the first side wall 605 and the second side wall 604. Therefore, the first side wall 605 and the second side wall 604 are bonded to the housing cover 402 at their respective end sides.Therefore, the bonded, preferably fluid-tight seal at the junction points 609 ensures that no cooling fluid enters the interior of the housing 4 from the cooling channel 6.

[0074] [Fig. 8] illustrates a perspective view of the cell contacting element configured as a cell connector 2. The cell connector 2 comprises an electrically conductive base body 211 made of flat material or as a cut-out. The base body 211 comprises the first contact surface 212 for electrically contacting a terminal 302 of the energy storage cell 3 and the second contact surface 213 for electrically contacting 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 thereto. The first side 215 of the cell connector 2 in this case comprises a region connecting the contact surfaces 212, 213.

[0075] 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 arranged in the cooling channel 6, the cell connector 2 can be cooled particularly effectively.

[0076] The cell contacting element designed as a module connector 220 comprises, according to [Fig. 9], an electrically conductive base body 221. The base body 221 comprises the contact surface 222 for electrically contacting a terminal (not shown in the figures) of an energy storage cell (not shown in the figures) preferably arranged at a front end of the energy storage module 1. The contact surface 222 is connected to the terminal, in particular soldered thereto. Furthermore, the module connector 220 comprises the socket 223 with a through hole 229 for fixing the socket 223, for example by means of a screw connection, to the housing 4. The first side 225 is connected in this case to the contact surface 222.

[0077] According to a first exemplary embodiment, the base bodies 211, 221 of the cell contacting elements 2, 220 are a bare, in particular uncoated, body. In this case, the electrically conductive base body 211, 221 of the respective cell contacting element 2, 220 can be in direct contact with a wall of the cooling channel 6. In addition, when using an electrically non-conductive coolant, the electrically conductive base body 211, 221 of the respective cell contacting element 2, 220 can penetrate into the cooling channel 6. Thus, an effective cooling effect is achieved.

[0078] [Fig. 10] illustrates a cross-section of the cell contacting elements 2, 220 according to a second exemplary embodiment. According to the second exemplary embodiment, a partial region 214, 224 of the cell contacting elements 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 cell contacting elements 2, 220.

[0079] [Fig. 11] illustrates a sectional view of the cell contacting element 2, 220 coated according to the second embodiment example according to [Fig. 10] in an arrangement 9. In this case, the coated partial region 214, 224 of the cell contacting element 2, 220 penetrates 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.

[0080] It is particularly advantageous here that the coating 217, 227 is a thermally conductive, electrically insulating material, in particular a thermally conductive, electrically insulating plastic material. Thus, the cell contacting element 2, 220 is insulated by the coating 217, 227, whereby an electrically conductive coolant can also be used. Preferably, the coating 217, 227 further has adhesion-promoting properties, so that the respective cell contacting elements 2, 220 can adhere to the cooling channel 6 or its wall directly without an additional adhesive agent.

[0081] The coating 217, 227 has in particular a thickness 218, 228 of less than 0.5 mm, preferably less than 0.4 mm, particularly preferably less than 0.3 mm.

[0082] The cell contacting elements 2, 220 are, via the cooling channel 6, permanently connected to each other without additional fastening means, so as to form a one-piece assembly. In this case, it may be a method in which the wall of the cooling channel 6 is brought into 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 can, for example, be carried out by means of a laser beam or by means of ultrasonic vibrations.

[0083] When heating the wall of the cooling channel 6 by ultrasound, an ultrasonic vibration is introduced into at least one partial region of the cooling channel 6 and heats it to its melting point. Suitably, the partial region is provided on the first side wall 605 or on the bottom wall 607. In this case, the at least one partial region is arranged in particular at the positions at which a cell contacting element 2, 220 is to be positioned. Thus, only the partial region of the cooling channel 6 is heated and melted, at which region a cell contacting element 2, 220 is to be connected to the cooling channel 6. In the case of several cell contacting elements 2, 220, several partial regions of the cooling channel 6 are in particular provided, into which the ultrasonic vibration is introduced.

[0084] Suitably, the ultrasonic vibration is introduced into the partial region of the cooling channel 6 via the 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 is to be introduced into the cooling channel 6.

[0085] Alternatively, the ultrasonic vibration may be introduced into the cooling channel 6 via an ultrasonic vibration transmitter, for example a sonotrode, in particular at the predetermined positions for the cell contacting elements 2, 220.

[0086] The cell contacting elements 2, 220 are introduced into the cooling channel 6 after heating the respective partial region of the cooling channel 6. In this case, the heated first 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 bottom wall 607 of the cooling channel 6. The melted partial region thus melt-surrounds the corresponding cell contacting element 2, 220. Then, the introduction of the ultrasonic vibration is completed and the partial region of the cooling channel 6 is solidified. This forms the melting 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 into the interior of the housing 4 from the cooling channel 6 at the fusion region 613.

[0087] Alternatively, a recess is provided in the cooling channel 6 in the predetermined position for the respective cell contacting element 2, 220 in the first side wall 605 or in the bottom wall 607, into which recess the corresponding cell contacting element 2, 220 can be pressed. In this case, in particular only the edge regions of the recesses are melted. The melted edge regions of the recesses then melt around the cell contacting elements 2, 220 pressed into the respective recesses and form the melting region 613 after solidification. The cell contacting elements 2, 220 preferably penetrate through the first side wall 605 into the interior of the cooling channel 6.

[0088] Alternatively, in the region of the first side wall 605, instead of a recess, a through opening can also be provided, which is dimensioned slightly smaller compared to the respective cell contacting element 2, 220, the edge region of which opening 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.

[0089] As an alternative to the ultrasonic method, the cell contacting elements 2, 220 can be injection-coated through the cooling channel 6 as injection-molded part during the manufacture of the cooling channel 6. By means of the injection-molding of the cell contacting elements 2, 220, a fluid-tight connection between the cell contacting elements 2, 220 and the cooling channel 6 is formed.

[0090] [Fig. 12] illustrates a part of the housing cover 402 of the energy storage module 1 in the region of the welding windows 410 in an enlarged representation. The welding windows in the housing cover 402 represent an original contribution of the invention. In the embodiment illustrated in [Fig. 12], several (e.g. four) welding windows 410 are provided respectively for each contact point 303. The welding 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.

[0091] In addition, the second stage 404 or the second offset, the shaped part for ensuring the snap-in connection 408, and the fastening tab 420 can also be seen in [Fig. 12]. The fastening tab 420 is located at the position on the housing cover 402 that corresponds to the through opening 411 on the housing base body 401. By means of the fastening tab 420, the energy storage module 1 can be fastened to a mounting surface not shown in the figures, for example by means of a screw (not shown). In the example of an energy storage module 1 shown in [Fig. 4], a total of four fastening tabs 420 are provided in the front region of the housing cover 402.

[0092] 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 relative to the degassing channels 6.

[0093] As can be seen in [Fig. 13], the individual welding windows 410 preferably have a slot-like shape, are formed 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.

[0094] 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 laser beam has entered, 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.

[0095] Preferably, the angle of narrowing considered with respect 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 onto the surface of the cell connector 2, which results in the representation according to [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 carrying out 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 onto the reflective surface of the cell connector 2. To improve the representation only, this reflection is shown rotated by 180°, i.e. upside down in [Fig. 15].

[0096] As an alternative to a circular path, several welding windows can also be arranged along an oval path at a contact point 303. By arranging several welding windows along a circular path or an oval path, it is achieved that the forces caused by welding are present in a regularly distributed manner and that no significant stress peaks are produced.

[0097] As can be seen in [Fig. 14], an air gap 423 is provided between the upper side of the cell connectors 2 and the opposite lower side of the welding window 410, which air gap prevents damage to the lower side of the housing cover 402 during the welding operation. To ensure the air gap 423, bearing projections 424 are molded on the lower side of the housing cover 402 laterally relative to the welding windows 410, which 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.

[0098] The measure of inserting welding windows 410 into the housing cover 402 enables 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 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. The laser beam 10 is oriented perpendicular to the cell connectors 2 or the module connectors 220.

[0099] The snap-in connection 408 between the housing cover 402 and the housing base body 401 enables easy-to-handle attachment of the housing cover 402 to the housing base body 401 and at the same time presetting of the welding windows 410 relative to the relevant contact points 303.

[0100] The above-mentioned procedure makes it possible to produce the housing cover 402 and the cell connectors as a prefabricated mounting unit.

[0101] Furthermore, the prefabricated mounting unit which comprises the housing cover 402 as well as the cell connectors 2 or the module connectors 220 may additionally comprise functional components, for example the following components: at least one cooling channel 6, preferably two cooling channels 6, the at least one cooling channel 6 or the preferably two cooling channels 6 being connectable in particular in one piece with the cell connectors 2, as shown in Figures 5a and 5b, and preferably in one piece with the module connector 220. Furthermore, the degassing channel 5 or at least components lining the degassing channel, for example the lining 407, may be part of the prefabricated mounting unit.By means of the module connector 220, the socket 223 of the energy storage module 1 can also be part of the prefabricated mounting unit, the same applies to the fastening lugs 420 for fastening the energy storage module 1 to an underlying fastening surface (not shown). Furthermore, retaining means, for example latching means for ensuring a latching connection between the housing cover 402 and the housing base body 401, can be provided on the housing cover 402.

[0102] In conclusion, the use of welding windows offers considerable advantages in terms of implementing the assembly sequence of an energy storage module 1.

[0103] The present invention therefore guarantees a considerable contribution to the technical field in question.

[0104] The elements, parts, components, pieces, indications and objects represented in the attached figures are referenced as follows:

[0105] 1 energy storage module

[0106] 2 cell connector

[0107] 211 basic body

[0108] 212 contact surface

[0109] 213 contact surface

[0110] 214 partial region [YES] 215 first side

[0112] 216 second side

[0113] 217 coating

[0114] 218 thickness

[0115] 219 recess

[0116] 220 module connector

[0117] 221 basic body

[0118] 222 contact surface

[0119] 223 power outlet

[0120] 224 partial region

[0121] 225 first side

[0122] 226 second side

[0123] 227 coating

[0124] 228 thickness

[0125] 229 through hole

[0126] 3 energy storage cell

[0127] 301 degassing opening

[0128] 302 terminal

[0129] 303 contact point

[0130] 4 box

[0131] 401 base housing body

[0132] 402 housing cover

[0133] 403 first floor

[0134] 404 second floor

[0135] 405 rib

[0136] 406 recess

[0137] 407 trim

[0138] 408 snap-on connection

[0139] 409 projection

[0140] 410 welding window

[0141] 411 through opening

[0142] 412 recess

[0143] 413 retaining rib

[0144] 414 retaining rib

[0145] 415 clamping corner

[0146] 416 snap hook

[0147] 417 side wall

[0148] 418 edge

[0149] 419 wall bevel

[0150] 420 fixing lug

[0151] 421 central part

[0152] 422 rib

[0153] 423 air space

[0154] 424 support projection

[0155]

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172]

[0173]

[0174] 425 circular path 5 degassing channel 6 cooling channel 601 opening 602 opening 604 side 605 side 606 opening 607 bottom 608 projection 609 junction point 612 connecting channel 613 melting region 7 printed circuit board 8 clamping strip 9 arrangement 10 laser beam 101 laser beam moving region B welding window width Of course, the invention is not limited to the embodiments described and represented in the attached drawings. Modifications remain possible, in particular from the point of view of the constitution 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 (402) 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), the energy storage cells (3) forming a venting surface with venting openings (301) arranged along the venting surface, which serve, in the event of an overpressure occurring in a critical situation in the energy storage cell (3) concerned, to allow gases to escape in a controlled manner from the interior of the energy storage cell (3) via the venting opening (301), and the housing cover (402) forming,by its side facing the energy storage cells, a degassing channel (5).,

2. Housing cover according to claim 1, characterized in that the housing cover (402) has an elongated shape and the degassing channel extends along the longitudinal direction of the housing cover (402).

3. Housing cover according to claim 1 or 2, characterized in that an interface, in particular fluid-tight, to a main degassing channel connecting to the energy storage module (1) or to an adjacent energy storage module is formed at at least one end of the housing cover (402), preferably at both ends of the housing cover (402).

4. Housing cover according to at least one of the preceding claims, characterized in that the housing cover (402) comprises, at its inner wall delimiting the degassing channel (5), a lining (407) which is in particular temperature-resistant and / or fire-resistant.

5. Housing cover according to claim 4, characterized in that the lining (407) is an insert made in particular in the form of a profile, preferably to be glued or to be welded.

6. Housing cover according to at least one of claims 1 to 4, characterized in that the housing cover (402) and the lining (407) are a multi-component injection-molded part.

7. Housing cover according to at least one of the preceding claims, characterized in that a groove-shaped recess (406), extending laterally along the degassing channel (5), is provided on the inner side of the housing cover (402), which recess (406) determines the position of a cooling channel (6).

8. Housing cover according to at least one of the preceding claims, characterized in that the housing cover (402) has ribs (405) spaced apart from each other, extending in the direction of the degassing surface, which ribs delimit the degassing channel (5) laterally.

9. Housing cover according to at least one of the preceding claims, characterized in that the housing cover (402) has on each side a respective first step or tier (403), so that the housing cover (402) rests on the cell connectors (2) in its respective outer region.

10. Housing cover according to at least one of the preceding claims, characterized in that the housing cover (402) has a respective second step or tier (404) on each side, so that the housing cover (402) encloses the cell connectors (2) on the outside in its outer region and rests in particular on the upper side of the arrangement of the energy storage cells (3).

11. Housing cover according to at least one of the preceding claims, characterized in that at least one mechanical connecting means, preferably several mechanical connecting means is or are provided for fixing the housing cover (402) to the housing base body (401).

12. Housing cover according to claim 11, characterized in that said at least one mechanical connecting means is a snap-on connection (408), preferably said several mechanical connecting means are snap-on connections (408).

13. Housing cover according to at least one of the preceding claims, characterized in that at least one rigid or flexible electrical conductor or conductive track is arranged between the housing cover (402) and the arrangement of the energy storage cells (3) laterally to the degassing channel (5), preferably on both sides of the degassing channel (5).

14. Housing cover according to claim 13, characterized in that the printed circuit board (7) is located on the lower side of the cooling channel (6).

15. 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 in particular open on one side for receiving the energy storage cells (3), and a housing cover (401) in particular made as a plastic molding, which closes the open side of the interior space.

16. Energy storage module comprising a plurality of energy storage cells (3), preferably prismatic energy storage cells or energy storage pouch cells, preferably lithium-ion energy storage cells, and a housing cover according to at least one of claims 1 to 15.

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