Battery module and battery module stack for a motor vehicle

Abstract

Battery module (10) for a motor vehicle comprising: - two contact plates (12, 13) arranged parallel or approximately parallel to each other, comprising a first contact plate (12) and a second contact plate (13), - at least two chambers (20.1, 20.2) arranged side by side and between the two contact plates (12, 13), comprising at least one first chamber (20.1) and at least one second chamber (20.2), - a plurality of battery cells (14) arranged side by side between the two contact plates (12, 13) and in the respective chambers (20.1, 20.2), and - a circulation system by means of which a cooling medium can be supplied to the first chamber (20.1), discharged from it and supplied to the second chamber (20.2), and discharged from it, wherein - each battery cell (14) has a longitudinal axis and two axially opposite ends, - the ends of each battery cell (14) are connected to the contact plates (12, 13), - a heat dissipation channel (18) is formed between mutually facing areas of outer circumferential surfaces (18.3) of adjacent battery cells (14), and - the first and / or the second contact plate (12, 13) has openings (12.2) through which the cooling medium can be supplied to or discharged from the respective heat dissipation channels (18) by means of the circulation system, wherein a filling material (18.2) is introduced into each heat dissipation channel (18) by means of which a flow cross-section of the heat dissipation channel (18) can be reduced, thereby increasing the flow velocity of the cooling medium.

Description

[0001] The present invention relates to a battery module for a motor vehicle with improved cooling and arrangement properties of the battery cells contained therein. The invention further relates to a battery module stack for a motor vehicle and to a motor vehicle comprising a battery module stack.

[0002] A battery, as commonly used in modern applications to power a motor vehicle, such as an electric or hybrid vehicle, typically consists of individual battery cells. Several of these individual cells are electrically interconnected and combined to form the battery. However, inefficiencies can arise in the arrangement of the individual cells regarding cooling and the utilization of available space, which can reduce the battery's performance and the vehicle's electric range.

[0003] From DE 10 2015 013 377 A1, a temperature control device for a battery system is known, comprising a cuboid hollow body with connection devices for supplying and discharging a temperature-controlled fluid. The hollow body has a plurality of openings, each opening accommodating a cylindrical battery cell. The battery cells are spaced apart from one another and surrounded by the fluid.

[0004] Furthermore, DE 10 2011 101 022 A1 discloses a battery pack with a plurality of battery cells and an arrangement for holding the battery cells. Further examples of battery modules are disclosed in DE 10 2014 206 646 A1 and DE 10 2010 013 021 A1.

[0005] The spacing between the battery cells prevents direct contact between them and the associated heat exchange. This reduces the efficiency of cell cooling and space utilization.

[0006] It is therefore an object of the present invention to overcome, or at least partially overcome, the disadvantages described above in a battery for a motor vehicle. In particular, it is an object of the present invention to provide a concept for a battery module with a plurality of battery cells and for a battery module stack, wherein the efficiency of the cooling of the battery cells and the space utilization by the battery cells is improved.

[0007] The foregoing problem is solved by the independent claims. Accordingly, the problem is solved by a battery module with the features of claim 1, by a battery module stack with the features of claim 9, and by a vehicle with the features of claim 10. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the battery module also apply in connection with the battery module stack or the vehicle, and vice versa, so that the disclosure of the individual aspects of the invention always makes, or can make, reciprocal references.

[0008] According to one aspect, the problem is solved by a battery module, preferably for a motor vehicle. The battery module comprises: - two contact plates arranged parallel or approximately parallel to each other, comprising a first and a second contact plate, - at least two chambers arranged side by side and between the two contact plates, comprising at least one first chamber and at least one second chamber, - a plurality of battery cells arranged side by side between the two contact plates and in the respective chambers, and - a circulation system by means of which a cooling medium can be supplied to the first chamber, discharged from it and supplied to the second chamber, and discharged from it.

[0009] Each battery cell has a longitudinal axis and two axially opposite ends. Preferably, the battery cell can have a cell housing and be tubular or approximately tubular, wherein, in particular, the longitudinal axes of battery cells can be parallel or approximately parallel to each other. The longitudinal axes of the battery cells can form axes of rotation or axes of symmetry of the battery cells.

[0010] The ends of each battery cell are connected to the contact plates, with each battery cell having a positive terminal at the first end and a negative terminal at the second end, and preferably the positive terminal being formed as a raised section on an end face of the battery cell at the first end. The positive terminal can be connected to the first contact plate and the negative terminal to the second contact plate.

[0011] A heat dissipation channel is formed between mutually facing areas of the outer circumferential surfaces of adjacent, touching battery cells, particularly those bounded by linear or strip-shaped contact areas. The corresponding contact areas can each define and preferably seal a heat dissipation channel. A contact area may be leaky, allowing a cooling medium circulating in one heat dissipation channel to flow into an adjacent heat dissipation channel. The cooling medium may, in particular, comprise a cooling liquid or possibly air.

[0012] The first and / or second contact plate has openings through which the cooling medium can be supplied to or discharged from the respective heat dissipation channels via the circulation system. This has the advantageous effect of ensuring that the circulation system or cooling circuit is functional and ready for operation.

[0013] According to another aspect, the problem is solved by a battery module stack, preferably for a motor vehicle. The battery module stack comprises several axially stacked battery modules according to the invention. The first contact plate of each battery module can be connected to the second contact plate of a battery module above it. - match or - be electrically connected.

[0014] This allows stacked battery modules of a battery stack to be or become electrically connected in series.

[0015] In this document, the terms "above," "below," "above," and "below" are to be understood from the perspective of an observer looking at a device (battery cell, battery module, or battery module stack) from the side, such that "above" refers to the north pole and "below" to the south pole of the respective device. Thus, the first end and the positive terminal are located at the north pole of the battery cell, and the second end and the negative terminal are located at the south pole of the battery cell. The arrangement of a second battery module above a first battery module is to be understood as meaning that the second battery module is located at or above the north pole of the first battery module.

[0016] According to another aspect, the problem is solved by a motor vehicle, preferably an electric vehicle or hybrid vehicle, with a battery module stack according to the invention.

[0017] The feature, in which a heat dissipation channel is formed between the facing areas of the outer circumferential surfaces of adjacent battery cells, creates the effect of direct contact between the cooling medium and the battery cells, as well as between adjacent battery cells that exchange heat directly with each other, without the need for or use of a separate cooling channel. One advantage of this effect is efficient, uniform cooling of the battery cells. A further advantage is a simplification of the cooling design (a separate cooling channel is eliminated) and the associated savings in material and costs.

[0018] The feature, wherein a battery module comprises at least two chambers arranged side by side and between the two contact plates, wherein at least one first chamber and at least one second chamber are provided, has several effects and associated advantages.

[0019] The chambers can each comprise a plurality of battery cells and at least one heat dissipation channel. Each chamber can be assigned to a region of the first and a region of the second contact plate, the respective region being continuously electrically conductive and optionally electrically insulated from adjacent regions of the same contact plate.

[0020] Advantageously, the separate chambers and the associated, area-specific conductivity of the contact plates allow for flexible electrical interconnection (in series or parallel) of battery cells of corresponding chambers among each other.

[0021] Each chamber can comprise a wall that laterally surrounds and encloses the battery cells arranged in the chamber. The wall can preferably be made of a thermally conductive and, in particular, electrically insulating material, preferably plastic.

[0022] The wall's properties create a heat exchange effect between adjacent chambers, allowing battery cells grouped or combined within each chamber to be electrically switched independently. The advantage of this effect is more uniform cooling or temperature control of the chambers and the enclosed battery cells, while maintaining flexibility regarding the electrical interconnection of the chambers, for example, in parallel or series as needed.

[0023] In a preferred embodiment of the invention, the battery cells can be arranged such that i) an outer circumferential surface of each battery cell, which is completely surrounded by adjacent battery cells, touches the outer circumferential surfaces of at least three adjacent battery cells, and ii) an outer circumferential surface of each battery cell, incompletely surrounded by adjacent battery cells, touches the outer circumferential surfaces of at least two adjacent battery cells.

[0024] The description of a battery cell as completely surrounded by neighboring battery cells (neighbor cells) means that the battery cell is embedded within neighboring cells, with neighboring cells located in a 360° environment around it. A battery cell completely surrounded by neighboring cells is not located at the edge of the battery cell space.

[0025] In contrast, describing a battery cell as incompletely surrounded (by neighboring cells) means that the battery cell is located at the edge of the battery cell space, with neighboring cells arranged only in a radius of less than 360° around it. This results in fewer neighboring cells and therefore fewer contacts with them.

[0026] Features i) and ii) of the battery module result in the following effects: firstly, the battery cells are arranged next to or next to each other in a space-saving manner, and secondly, mutual heat exchange is achieved between contacting battery cells, particularly because the cell casing of each battery cell is made, or can be made, of a thermally conductive material, such as a metal or plastic. One advantage of these effects is that the space available for the battery cells can be used with high efficiency and high packing density, without redundant gaps; in other words, the battery cells can be arranged in a space-optimized manner. A further advantage is that a balanced temperature distribution among the battery cells can be achieved without the need for a separate cooling channel.Direct contact between coolant and battery cells, without a separate cooling channel, enables or ensures improved cooling efficiency of the battery cells.

[0027] Preferably, the outer circumferential surface of each battery cell, which is completely surrounded by adjacent battery cells, can contact the outer circumferential surfaces of at least five, preferably six, adjacent battery cells. In particular, the outer circumferential surface of each battery cell, which is partially surrounded by adjacent battery cells, can contact the outer circumferential surfaces of at least three or four adjacent battery cells.

[0028] Advantageously, as the number of neighboring cells in contact increases, so do the space savings and packing density of the battery cells. The maximum number of neighboring cells that a single battery cell can contact is six (assuming all involved battery cells have the same diameter). Consequently, maximum packing density and space savings are achieved when a battery cell contacts six neighboring cells.

[0029] The cell casing can be connected to the negative terminal and be electrically conductive, but in a state where the battery cells are not mounted in the battery module, it must be electrically insulated from the positive terminal to ensure the basic functionality of the battery.

[0030] In a preferred embodiment of the invention, the positive terminal can be directly connected to the first contact plate and the negative terminal to the second contact plate. Here, a direct connection is to be understood as an immediate, unmediated connection without an intermediate element. A connection between the positive terminal and the first contact plate via an intermediate element, for example a spring, is not to be considered a direct connection.

[0031] This feature creates the technical effect that an electric current can flow along the current path between the positive terminal and the first contact plate with no loss or only minimal conduction losses. In other words, the current path exhibits high electrical conductivity and low electrical resistance. This effect offers the advantage of improved battery performance and a greater electric range for the vehicle in which the battery is installed. Batteries where the positive terminal and the first contact plate are not directly connected but indirectly, for example via a contact spring, exhibit higher conduction losses.

[0032] In a preferred embodiment of the invention, it can be ensured that, particularly in a state where the battery cell is mounted in the battery module, the cell housing is electrically insulated from the first contact plate, and thus preferably from the positive terminal, thereby electrically isolating the positive and negative terminals of a battery cell from each other when the battery cell is mounted in the battery module. Due to the insulation of the first contact plate from the cell housing, the negative terminal of the battery cell is also electrically insulated from the first contact plate.

[0033] This feature results in a simpler battery module structure, as no measures, or at least no complex or costly measures, are needed to insulate the cell housing from the first contact plate. This effect reduces the complexity, construction costs, and assembly effort of the battery module.

[0034] In a preferred embodiment of the invention, a battery module may be provided in such a way that the positive terminal of each battery cell is permanently connected to the first contact plate. A permanent connection can be produced, for example, by laser welding, i.e., a laser weld joint, or by bonding, or by a press fit, or a butt joint.

[0035] The permanent (non-removable) connection has the effect of further reducing electrical current losses on the current path between the positive terminal and the first contact plate, since the contact area is preferably increased and the contact resistance between elements connected via a permanent connection is lower than between loosely touching elements. This effect has the advantage of further improving battery performance and increasing the vehicle's electric range.

[0036] As an alternative to a permanent connection, a detachable electrical connection can also be used, for example, a positive-locking and / or friction-locking connection, provided that sufficiently high mechanical forces act on the elements to be connected and / or the contact area is large. In this case, the contact resistance or transition resistance can also be advantageously reduced. A plug connector can preferably be used for this purpose.

[0037] To achieve a positive-locking and / or force-locking connection, the first contact plate can have openings, preferably at the intersections of the longitudinal axes of the respective battery cells with the first contact plate. In addition, the positive terminal of each battery cell can project into an opening of the first contact plate in the axial direction away from the housing, thereby creating a force-locking and direct connection between the positive terminal and the first contact plate.

[0038] Preferably, a positive-locking and / or force-locking connection can be designed as a plug connection with a socket connector and a pin connector that can be inserted into the socket connector, wherein the positive terminal of each battery cell forms the pin connector and the opening of the first contact plate forms the socket connector. In the simplest case, the socket connector, designed as an opening, can have a smooth edge (ordinary embodiment or normal case of an opening or hole).

[0039] Alternatively, if the opening edge is smooth, the socket plug can have an inner diameter that is slightly smaller than the outer diameter of the pin plug, or the lateral flanks of the positive pole can be slightly inclined in the axial direction, so that the positive pole forms a truncated cone that tapers upwards.

[0040] According to both embodiments of the connector, it is ensured that i) the pin connector exerts radial forces on the socket connector in a contact area, and / or ii) the contact area has a large contact surface, thereby improving the electrical contact of the connector or reducing the corresponding contact resistance.

[0041] Alternatively, a socket connector (opening of the first contact plate) can have an opening edge formed from flexible, elastic lamellae, so that when the pin connector is inserted into the socket connector, the lamellae are elastically spread, exerting a radial force on the pin connector due to their elasticity, and thus mechanically locking or fixing the pin connector in the socket connector in the axial direction. Despite this locking action, the elasticity of the lamellae ensures a certain degree of axial movement for the pin connector or the positive terminal of the battery cells.

[0042] The force exerted by the lamellae on the pin connector and the large contact area reduce the electrical contact resistance of the connector, i.e., the contact resistance between the negative terminal and the second contact plate, which offers the advantage of improved battery performance or an increase in the electric range of the vehicle.

[0043] In a preferred embodiment of the invention, a battery module can comprise an electrically non-conductive, preferably elastic, insulating element that is arranged between the cell housing of each battery cell and the first contact plate.

[0044] Due to its electrically insulating properties and its position, the insulating element electrically isolates the cell housing from the first contact plate. This effect has the advantage of allowing for manufacturing tolerances in the battery cells and contact plates, as well as assembly tolerances regarding the arrangement and positioning of the battery module components. This is because the insulating element significantly reduces the probability of accidental electrical contact between the first contact plate and the cell housing of a given battery cell, a contact caused by manufacturing or assembly tolerances. This, in turn, advantageously reduces the costs of manufacturing and assembling the battery module and / or battery module stack.

[0045] Preferably, an insulating element can be plate-shaped, in particular as an elastomer or an elastic membrane. Alternatively, the insulating element can also be ring-shaped, for example in the form of an insulating ring or a plurality of insulating rings, and can be arranged around the positive terminal at the first end of each battery cell.

[0046] The elasticity of a plate-shaped or ring-shaped insulating element advantageously allows the first contact plate to be pressed against the battery cells during assembly of the battery module until a secure and stable structure is achieved, without having to fear accidental contact of the cell housing of a respective battery cell by the first contact plate.

[0047] Preferably, the lateral dimensions of an insulating element, particularly a plate-shaped one, can be equal to or approximately equal to the lateral dimensions of the first or second contact plate. This has the effect that the insulating element covers the entire space between the battery cells beneath the first contact plate. This effect can advantageously facilitate and simplify the assembly of the battery module, as well as increase electrical safety by reducing the probability of unwanted electrical contacts or short circuits.

[0048] Preferably, an insulating element can have openings, particularly at the intersections of the longitudinal axes of the respective battery cells with the insulating element, such that each opening of the insulating element is located above the positive terminal of each battery cell, allowing the positive terminal to pass through the opening. This advantageously facilitates and simplifies the assembly of the battery module and increases electrical safety.

[0049] Advantageously, the positive terminal of each battery cell can protrude axially through an opening in the insulating element, away from the housing. This has the effect of separating the cell housing from the first contact plate by the insulating element, thus electrically isolating it.

[0050] When assembling a battery module stack, it can be pressed together axially. This allows for the creation of a positive-locking and / or force-locking connection using the described plug connectors. The insulating element can match the shape and dimensions of the first contact plate exactly or approximately, so that the assembly of a battery module and / or battery module stack can comprise the following steps: a) Providing a second contact plate, or placing the second contact plate on top of the first contact plate of an underlying battery module, for the mounting of a first battery module; b) Arranging several battery cells approximately perpendicular to the contact plate and approximately parallel to the axis of the second contact plate, so that the negative terminal of each battery cell electrically contacts the second contact plate; c) direct connection of the negative terminals of the battery cells to the second contact plate, in particular by means of a non-removable connection, preferably by means of laser welding; d) Place the plate-shaped insulating element loosely onto the battery cells so that the positive terminals of the battery cells can penetrate and / or enter the openings of the insulating element; e) Placing the first contact plate loosely onto the plate-shaped insulating element, whereby the positive terminals of the battery cells can penetrate or do penetrate the openings of the first contact plate; f) Pressing the first contact plate axially against the second contact plate; g) Repeat the preceding steps for the second and for each additional battery module to be added.

[0051] The axial compression in step f) of the structure obtained in steps a) to e) enables the positive terminal of each battery cell to be electrically conductive and directly and / or inseparably or only with difficulty connected to the second contact plate.

[0052] In a preferred embodiment of the invention, in step c) the connection between the negative terminal of each battery cell and the second contact plate can be implemented as a plug connection, as an alternative to a connection by welding, in particular laser welding. For this purpose, the second contact plate can have openings, and the negative terminal of the battery cell can be formed as a raised section on the end face of the battery cell at its second end, analogous to the positive terminal. Furthermore, the above statements regarding the plug connection between the positive terminal and the first contact plate also apply to this plug connection. Advantageously, with such an implementation, the assembly of the battery module and / or battery module stack can be significantly simplified, and the associated costs can be considerably reduced.

[0053] In a preferred embodiment of the invention, a battery module can be provided such that the positive terminal of each battery cell projects axially away from the housing in a direction beyond its first end, preferably also beyond the insulating element. This has the effect that the raised portion of the end face of each battery cell, representing the positive terminal, mechanically supports the first contact plate in the axial direction and simultaneously forms a spacer between the first contact plate and the cell housing. The cell housing is thus spaced apart from the first contact plate and consequently also electrically insulated. This effect has the advantage of a simple and cost-effective reduction in the complexity and assembly effort, as well as the associated costs, for assembling the battery module.

[0054] In a preferred embodiment of the invention, a first and / or second contact plate can each be electrically conductive in certain areas or throughout. This has the effect that battery cells can be connected in parallel in certain areas or throughout. This effect has the advantage that battery cells of corresponding areas can be arranged or grouped together in different and separate groups or compartments in order to be able to electrically switch corresponding groups or compartments independently of one another, for example, electrically in parallel or in series as required.

[0055] If the first and second contact plates are both electrically conductive throughout, then all the battery cells in between are connected in parallel.

[0056] In a preferred embodiment of the invention, a first and / or second contact plate can be elastic and preferably made of a conductive and elastic material, in particular a metal or plastic, wherein the material returns to its original position after deformation and after the deformation force is removed. The first and / or second contact plate can comprise an elastic membrane in a contact area with the battery cell, which is optionally curved in a direction away from the battery cell and may have an opening. To improve electrical conductivity, the first and / or second contact plate can be coated in the contact area with a contact paste that improves electrical conductivity and comprises, for example, copper, aluminum, or graphite pigments.

[0057] The further development achieves the effect of compensating for potential thermal or tolerance-related fluctuations in the axial length of each battery cell, preferably while simultaneously reducing the contact resistance in the contact area. This effect has the advantage that a) Manufacturing tolerances for battery cells and contact plates, and / or assembly tolerances regarding the arrangement or positioning of the components of the battery module may be permitted, and / or b) improved battery performance and a higher electric range of the vehicle can be achieved without complex welding between a battery cell and a contact plate.

[0058] This can advantageously reduce the costs for manufacturing and assembling the battery module and / or battery module stack considerably.

[0059] In a preferred embodiment of the invention, the outer circumferential surface of one battery cell can contact the circumferential surface of an adjacent battery cell in a linear or strip-shaped contact area. Ideally, a linear contact area occurs, while a strip-shaped contact area is more common in practice. The contact area may have interruptions along its length and therefore consist of successive linear or strip-shaped contact areas due to possible irregularities in the circumferential surface of a battery cell. The effectiveness of heat dissipation between contacting battery cells increases with increasing width of the contact area.

[0060] Preferably, the respective heat dissipation channel can be permeated by the cooling medium to cool adjacent battery cells. For this purpose, the cooling medium can be pumped or forced into the heat dissipation channel and discharged from the end of the channel. Advantageously, the circulation of the cooling medium promotes the cooling of the battery cells.

[0061] In a preferred embodiment of the invention, a battery module can comprise a circulation system by means of which the cooling medium can be supplied to and discharged from a heat dissipation channel. Advantageously, the circulation system enables autonomous or self-sufficient operation of the battery module and / or battery module stack.

[0062] In a preferred embodiment of the invention, a circulation system can be configured to move or circulate the cooling medium such that the cooling medium is supplied to the first chamber, discharged from it, and supplied to the second chamber, from which it is again discharged. If several heat dissipation channels are provided in each chamber, the cooling medium moves or flows uniformly in one direction through the heat dissipation channels of the respective chamber. This creates the effect of a closed cooling circuit, with the cooling medium circulating through and between the chambers. This effect has the advantage of enabling a compact design of the battery module or battery module stack and / or uniform temperature control of the battery cells.

[0063] Preferably, connections can be provided through which the cooling medium can be supplied to and / or discharged from a chamber. These connections can be located above the first or below the second contact plate. This results in the advantageous effect of a compact design for the battery module or battery module stack, because the circulation system or cooling circuit and the battery module together form a self-contained, autonomous, or self-sufficient unit that can be housed in a battery casing or overall enclosure.

[0064] Preferably, the connections can include one or more inlets, for example at least two, five, or ten, for supplying the coolant to each individual chamber. Furthermore, the connections can include one or more outlets, preferably at least two, five, or ten, for removing the coolant from each chamber. A high number of connections results in a highly or finely branched cooling circuit. The advantage of this effect is a good and uniform distribution of heat dissipation from the battery cells and a uniform temperature control of the battery cells.

[0065] In a preferred embodiment of the invention, a filling material can be introduced or is introduced into each heat dissipation channel. The introduced filling material produces the effect i) a reduction of the flow cross-section in the heat dissipation channel, which is preferably accompanied by an increase in the flow velocity of the cooling medium in the heat dissipation channel, and / or ii) a reduction in the amount of circulating cooling medium required.

[0066] Effect i) has the advantage of improved cooling efficiency for the battery cells, and effect ii) has the advantage of saving materials and costs.

[0067] Preferably, the filling material can comprise an axial rod or hollow spheres made of glass or plastic. This offers the advantage of a structurally simple and cost-effective way to increase cooling efficiency and save material.

[0068] In a preferred embodiment of the invention, a circulation system can comprise a heat exchanger or a cooling device for cooling the cooling medium. The heat exchanger can be arranged in an interior region of the battery module or battery module stack, for example, in a lateral region of the interior. In a battery module stack with multiple battery modules, the cooling medium can be introduced into the first battery module and discharged from the axially opposite battery module, with the discharged fluid circulating through the heat exchanger and being cooled there. The circulation system thus formed, including the heat exchanger, offers the advantage of an increased cooling effect and a compact design for the battery module or battery module stack.

[0069] The circulation system also works when the battery module stack consists of a single battery module or when each battery module comprises a single chamber.

[0070] In a preferred embodiment of the invention, an opening in the second contact plate or the insulating element can be located directly or immediately adjacent to the respective heat dissipation channel. This has the advantageous effect of preventing the outflow of cooling medium at the transition into the heat dissipation channel. In particular, the insulating element fulfills a sealing function, similar to a seal between components of a fluid line system.

[0071] In a preferred embodiment of the invention, the battery module or battery module stack can comprise a battery housing (overall housing), preferably made of aluminum, for accommodating the battery module or battery module stack. This has the advantage of improved and easier handling of the battery module and / or battery module stack.

[0072] Preferably, a battery module or battery module stack can comprise electrically non-conductive and optionally mechanically shock-absorbing insulating rings that completely enclose the battery module stack, electrically insulate the contact plates from the battery housing, and reduce or prevent movement of battery components relative to the battery housing. This has the advantage of enabling or ensuring electrically safe operation and improved mechanical stability and shock resistance.

[0073] The vehicle has the same advantages already described above with regard to the battery module and battery module stack according to the invention.

[0074] A battery module according to the invention is explained in more detail below with reference to the drawings. The drawings schematically show: Fig. 1a in a perspective view a battery module with the first contact plate missing, Fig. 1b in a perspective view a preferred embodiment of a battery module, Fig. 2a in a perspective view a plurality of battery cells of a battery module arranged next to each other, Fig. 2b in a side view a single battery cell, Fig. 3 in a perspective view, a first contact plate, Fig. 4a shows a stack of battery modules in a perspective view, Fig. 4b shows a section through a battery module stack in a front view, to visualize the fluid flow of the cooling medium. Fig. 4c shows a cross-section in a top view through a heat dissipation duct with filling material inserted therein, Fig. 5 in a front view a schematic representation of a fluid flow of the cooling medium through a battery module stack, Fig. 6 in a top view a section through a battery module, and Fig. 7 shock-absorbing insulation rings in a perspective view.

[0075] Elements with the same function and mode of operation are each provided with the same reference symbols in the figures shown.

[0076] Fig. Figure 1a shows a battery module 10 with a missing first contact plate, Fig. Figure 1b shows a complete battery module 10, and Fig. Figure 6 shows a section through a battery module 10. The battery module 10 comprises: - two contact plates 12, 13, arranged parallel or approximately parallel to each other, comprising a first and a second contact plate, and - at least two chambers arranged side by side and between the two contact plates, comprising at least one first chamber and at least one second chamber, - a plurality of battery cells arranged side by side between the two contact plates and in the respective chambers, and - a circulation system by means of which a cooling medium can be supplied to the first chamber, removed from it and supplied to the second chamber, and removed from it.

[0077] The first chamber 20.1 and the second chamber 20.2 are each assigned to a region of the first and a region of the second contact plate 12, 13, respectively, wherein the respective region is continuously electrically conductive and optionally electrically insulated from adjacent regions of the same contact plate 12, 13. Preferably, the separate chambers 20.1, 20.2 and the associated partial conductivity of the contact plates 12, 13 enable flexible electrical interconnection (in series or parallel) of battery cells 14 belonging to the chambers 20.1, 20.2 with each other.

[0078] Each chamber 20.1, 20.2 comprises a wall 20 that laterally surrounds and encloses the battery cells arranged in the chamber. The wall is made of a thermally conductive and, in particular, electrically insulating material. This enables efficient heat exchange between adjacent chambers 20.1, 20.2, whereby battery cells 14 grouped or combined in each chamber 20.1, 20.2 can be electrically switched independently of one another. This advantageously allows for more uniform cooling or temperature control of the chambers 20.1, 20.2 and the battery cells 14 enclosed therein.

[0079] Fig. Figure 2b shows a single battery cell 14 in a side view. Each battery cell 14 has a cell housing 14.1, a longitudinal axis, and two axially opposite ends. The battery cell 14 is tubular, with the longitudinal axes of the battery cells 14 being parallel to each other. The longitudinal axes of the battery cells 14 form axes of rotation or axes of symmetry of the battery cells 14.

[0080] Each battery cell 14 has a positive terminal 14.2 at its first end and a negative terminal 14.3 at its second end. The positive terminal 14.2 is formed as a raised area on the end face of the battery cell 14 at its first end.

[0081] The positive terminal 14.2 is directly connected to the first contact plate 12 and the negative terminal 14.3 is directly connected to the second contact plate 13 (see Fig. 1).

[0082] The cell casing 14.1 is connected to the negative terminal 14.3 and is electrically conductive, while in a state where the battery cells 14 are not mounted in the battery module 10, it is electrically insulated from the positive terminal 14.2; this ensures the basic functionality of the battery.

[0083] Between mutually facing areas of outer circumferential surfaces, particularly those bounded by linear or strip-shaped contact areas 18.3 (see also Fig. 4c) Between adjacent, touching battery cells 14, a heat dissipation channel 18 is formed. The corresponding contact areas each define and seal a heat dissipation channel 18. If a contact area is leaking, then a cooling medium circulating in one heat dissipation channel 18 flows into an adjacent heat dissipation channel 18. In this embodiment, the cooling medium is a coolant.

[0084] The first and / or second contact plate 12, 13 has openings through which the cooling medium can be supplied to or removed from the respective heat dissipation channels 18 by means of the circulation system.

[0085] When the battery cell 14 is mounted in the battery module 10, the cell housing 14.1 is electrically insulated from the first contact plate 12 and thus advantageously also from the positive terminal 14.2, whereby the positive terminal 14.2 and the negative terminal 14.3 of each battery cell 14 are electrically insulated from each other when the battery cell 14 is mounted in the battery module 10. Due to the insulation of the first contact plate 12 from the cell housing 14.1, the negative terminal 14.3 of the battery cell 14 is also electrically insulated from the first contact plate 12.

[0086] Fig. Figure 2a shows a perspective view of a plurality of battery cells 14 arranged side by side in a battery module 10. The battery cells 14 are arranged such that (see also Fig. 4c) i) an outer circumferential surface 18.3 of each battery cell 14.5, which is completely surrounded by adjacent battery cells 14, touches the outer circumferential surfaces of at least four adjacent battery cells 14, and ii) an outer circumferential surface 18.3 of each battery cell 14.6, which is incompletely surrounded by adjacent battery cells 14, touches the outer circumferential surfaces of at least two adjacent battery cells 14.

[0087] A battery cell 14.5, completely surrounded by neighboring battery cells 14 (neighbor cells), is embedded in the middle of neighboring cells, with neighboring cells located in a 360° environment around the battery cell 14.5.

[0088] An outer circumferential surface 18.3 each of one in Fig. 2a shown, battery cell 14.5, which is completely surrounded by neighboring battery cells 14, touches outer circumferential surfaces 18.3 of six neighboring battery cells 14.

[0089] A battery cell 14.6, incompletely surrounded by neighboring battery cells 14 (neighbor cells), is located in a peripheral region of the battery cell space, with neighboring cells arranged only in a radius of less than 360° around the battery cell 14.6.

[0090] An outer circumferential surface 18.3 each of one in Fig. 2a shows battery cell 14.6, which is incompletely surrounded by neighboring battery cells 14, touching outer circumferential surfaces 18.3 of three neighboring battery cells 14.

[0091] Between mutually facing areas of the outer circumferential surfaces of adjacent, touching battery cells 14, which are bounded by linear or strip-shaped contact areas, there is in each case a Fig. 2a shows a heat dissipation channel 18. The corresponding contact areas each define and seal a heat dissipation channel 18.

[0092] Fig. Figure 3 shows a first contact plate 12 in a perspective view. To achieve a positive-locking and / or force-locking connection between the positive terminal 14.2 of a battery cell 14 and the first contact plate 12, the first contact plate 12 has openings 12.1 at the intersections of the longitudinal axes of the respective battery cells 14 with the first contact plate 12. In addition, the positive terminal 14.2 of each battery cell 14 projects into each opening 12.1 of the first contact plate 12 in the axial direction away from the housing, thereby forming a force-locking and direct connection between the positive terminal 14.2 and the first contact plate 12. Alternatively, in addition to or instead of a positive-locking and / or force-locking connection, the positive terminal 14.2 of each battery cell 14 is permanently connected to the first contact plate 12, preferably by laser welding.

[0093] According to Fig. 1 and Fig. 3 The first contact plate has openings 12.2 through which the cooling medium can be supplied to or discharged from the respective heat dissipation channel 18 by means of a (not shown) circulation system.

[0094] Fig. Figure 4a shows a battery module stack 11. This stack comprises several axially stacked battery modules 10 according to the invention. The first contact plate 12 of each battery module 10 is electrically connected to the second contact plate 13 of a battery module 10 stacked above it. This connects the stacked battery modules 10 of a battery stack electrically in series.

[0095] Fig. Figure 4b shows a section through a battery module stack 11 to visualize a fluid flow 18.1 of the cooling medium, with the fluid flows 18.1 being shown as arrows. In addition, Figure 4b shows... Fig. Figure 5 shows a schematic representation of a fluid flow of the cooling medium through a battery module stack. Each arrow symbolizes a multitude of fluid flows 18.1 through respective heat dissipation channels 18. The central upward-pointing arrow represents fluid flows 18.1 through the central, first chamber 20.1, while the two downward-pointing lateral arrows represent fluid flows 18.1 through the lateral, second chambers 20.2. The central fluid flow is deflected in the upper region of the battery module stack 11 and introduced into the heat dissipation channels 18 of the lateral second chambers 20.2.

[0096] The fluid flows described are part of a circulation system that also includes a heat exchanger and a pump. The cooling medium, cooled by the (not shown) heat exchanger, is pumped by the (not shown) pump in the form of an upward fluid flow. The downward-flowing, warmed fluid flows are fed to the heat exchanger and then pumped back upwards into the central chamber 20.1. The circulation system thus constitutes a closed cooling circuit.

[0097] Fig. Figure 4c shows a section through a heat dissipation channel 18 with filler material 18.2 inserted therein. In this case, the filler material is an axial rod made of plastic. The filler material causes - a reduction of the flow cross-section in the heat dissipation channel, which results in an increase in the flow velocity of the cooling medium in the heat dissipation channel and a corresponding improvement in cooling efficiency, and - a reduction in the amount of circulating cooling medium required, resulting in material and cost savings.

[0098] Fig. Figure 7 shows shock-absorbing insulating rings 10.1, in a perspective view, separate from the battery module stack 11. The insulating rings are designed to fully enclose the battery module stack 11, to electrically insulate the contact plates 12, 13 from a battery housing (not shown), and to reduce or prevent any movement of battery components relative to the battery housing. Reference symbol list 10 battery modules 10.1 Shock-absorbing insulation ring between battery module and battery housing or overall housing 11 battery module stacks 12 first contact plate 12.1 Opening of the first contact plate for a battery cell positive terminal 12.2 Opening of the first contact plate for a heat dissipation channel 13 second contact plate 14 battery cells 14.1 Cell casing 14.2 Positive terminal of a battery cell 14.3 Negative terminal of a battery cell 14.5 Battery cell completely surrounded by adjacent battery cells 14.6 Battery cell incompletely surrounded by neighboring battery cells 16 Insulation elements arranged between a battery cell and the first contact plate 16.1 Opening of the insulating element for a battery cell positive terminal 16.2 Opening of the insulation element for a heat dissipation channel 18 Heat dissipation channel 18.1 Fluid flow 18.2 Filling material, axial rod in a heat dissipation channel 18.3 Wall of the heat dissipation channel, outer battery cell perimeter surface 20 Wall of a chamber 20.1 first chamber 20.2 second chamber

Claims

[1] Battery module (10) for a motor vehicle comprising: - two contact plates (12, 13) arranged parallel or approximately parallel to each other, comprising a first contact plate (12) and a second contact plate (13), - at least two chambers (20.1, 20.2) arranged side by side and between the two contact plates (12, 13), comprising at least one first chamber (20.1) and at least one second chamber (20.2), - a plurality of battery cells (14) arranged side by side between the two contact plates (12, 13) and in the respective chambers (20.1, 20.2), and - a circulation system by means of which a cooling medium can be supplied to the first chamber (20.1), discharged from it and supplied to the second chamber (20.2), and discharged from it, wherein - each battery cell (14) has a longitudinal axis and two axially opposite ends, - the ends of each battery cell (14) are connected to the contact plates (12, 13), - a heat dissipation channel (18) is formed between mutually facing areas of outer circumferential surfaces (18.3) of adjacent battery cells (14), and - the first and / or the second contact plate (12, 13) has openings (12.2) through which the cooling medium can be supplied to or discharged from the respective heat dissipation channels (18) by means of the circulation system, wherein a filling material (18.2) is introduced into each heat dissipation channel (18) by means of which a flow cross-section of the heat dissipation channel (18) can be reduced, thereby increasing the flow velocity of the cooling medium. [2] Battery module (10) according to claim 1, comprising at least one of the following features: - the first and second contact plates (12, 13) are each partially or completely electrically conductive, whereby battery cells (14) are connected in parallel partially or completely; - Each chamber (20.1, 20.2) comprises a wall (20) which laterally surrounds and encloses battery cells (14) arranged in the chamber (20.1, 20.2) and is preferably made of a thermally conductive and, in particular, electrically insulating material, optionally of plastic. [3] Battery module (10) according to at least one of claims 1 or 2, comprising at least one of the following features: - the respective heat dissipation channel (18) is permeable to a cooling medium, preferably a cooling liquid or possibly air, for cooling adjacent battery cells (14); - the circulation system has connections by means of which the cooling medium, preferably cooling liquid, can be supplied to and / or discharged from a chamber (20.1, 20.2), and preferably the connections are arranged above the first contact plate (12) or below the second contact plate (13); - the connections include one or more, preferably at least two, five or ten, inlets for supplying the coolant to each chamber (20.1, 20.2); - the connections include one or more, preferably at least two, five or ten, drains for removing the cooling medium from each chamber (20.1, 20.2). [4] Battery module (10) according to at least one of the preceding claims, comprising at least one of the following features: - the battery cells (14) are arranged such that the outer circumferential surface (18.3) of each battery cell (14.5) completely surrounded by adjacent battery cells (14) is surrounded by at least three or four, preferably six, adjacent - the battery cells (14) are arranged such that the outer circumferential surface (18.3) of each battery cell (14.6) incompletely surrounded by adjacent battery cells (14) touches the outer circumferential surfaces (18.3) of at least two, three or four adjacent battery cells (14); [5] Battery module (10) according to at least one of the preceding claims, wherein - the outer circumferential surface (18.3) of a battery cell (14) touches the circumferential surface (18.3) of an adjacent battery cell (14) in a linear or strip-shaped contact area. [6] Battery module (10) according to at least one of the preceding claims, comprising at least one of the following features: - Each battery cell (14) has a positive terminal (14.2) at the first end, a negative terminal (14.3) at the second end and a cell housing (14.1), wherein the positive terminal (14.2) is directly connected to the first contact plate (12) and the negative terminal (14.3) is directly connected to the second contact plate (13); - the positive terminal (14.2) is directly connected to the first contact plate (12) and the negative terminal (14.3) is directly connected to the second contact plate (13). [7] Battery module (10) according to at least one of the preceding claims, wherein - the cell housing (14.1) is electrically insulated from the first contact plate (12). [8] Battery module (10) according to at least one of the preceding claims, comprising at least one of the following features: - the positive terminal (14.2) of each battery cell (14), preferably formed as a raised end face of the battery cell (14) at the first end, is inseparably connected to the first contact plate (12), in particular by means of laser welding; - the negative terminal (14.3) of each battery cell (14) is inseparably connected to the second contact plate (13), preferably by means of laser welding. [9] Battery module stack (11) for a motor vehicle, comprising several axially stacked battery modules (10) according to at least one of the preceding claims, wherein preferably the battery modules (10) are electrically connected in series. [10] Motor vehicle with a battery module stack (11) according to the preceding claim.

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