Cell block for an electric battery

Abstract

Cell block (1) for an electric battery with - a plurality of electrically interconnected individual cells (2), - which are each held in a shell- and / or frame-shaped holding element (5) made of plastic, and - at least one clamping element (6) by means of which the individual cells (2) are clamped together, characterized in that - between each of the individual cells (2) at least one heat-conducting plate (4) made of metal and intended for coupling with a temperature control device (3) is arranged, - the retaining elements (5) are mechanically connected to the at least one clamping element (6) via the heat-conducting plates (4), - each heat-conducting plate (4) is connected to a retaining element (5) in a material- and / or form-fit manner, wherein the heat-conducting plate (4) is at least partially overmolded with the plastic of the retaining element (5), and - the heat-conducting plate (4) in a connection area provided for connection with the clamping element (6) includes at least one tab (4.2 to 4.5) which extends out of the retaining element (5).

Description

[0001] The invention relates to a cell block for an electric battery according to the preamble of claim 1.

[0002] Electrical batteries are generally known from the prior art. Such electrical batteries each comprise a plurality of individual cells connected electrically in series and / or parallel.

[0003] Within an electric battery, the individual cells are grouped into at least one cell block, which comprises a number of individual cells and devices for their mechanical fixation, contacting, and / or temperature control. The cell block is housed in a robust battery casing, which also contains necessary devices for the electrical control and protection of the battery, such as a battery management system, contactors for switching the electrical current on and off, fuses, ammeters, as well as connections for current supply and discharge, coolant supply and discharge, and connections for a battery control system.

[0004] From DE 10 2013 015 786 A1, a battery is known comprising a number of individual cells connected electrically in series and / or parallel, which are combined to form a cell block. Two clamping elements are arranged on opposite sides of the cell block, the clamping elements extending over a longitudinal dimension of the cell block and having fixing elements at predetermined positions, to which each individual cell is directly or indirectly fixed in a predetermined orientation and at a predetermined distance relative to at least one other individual cell. Each individual cell is arranged between two shell- or frame-shaped retaining elements made of plastic, which are positively connected to the fixing elements of the clamping elements.

[0005] Furthermore, an electrochemical battery with multiple individual cells is known from DE 10 2011 103 965 A1. The individual cells comprise a cell housing and an electrochemically active electrode stack arranged in the cell housing. A spacer is arranged between each individual cell to set a defined distance between the terminal contacts of adjacent individual cells, and the individual cells are thermally coupled to a heat-conducting plate. The spacers are each designed as a heat-conducting element and are thermally coupled to the heat-conducting plate. Cooling fins are integrated into the spacers. The individual cells are pressed onto the heat-conducting plate by means of clamping elements, the clamping elements being formed by the spacers. The spacers are made of metal.

[0006] WO 2014 / 103 007 A1 describes an electric battery with multiple individual cells and a battery holder. The battery holder holds the individual cells, which are automatically aligned during battery assembly. Several individual cells are arranged in a row and pressed against each other in a first direction, with the battery holders positioned between the individual cells. The battery holders include a positioning means that positions the individual cells by biasing them in a further direction, intersecting the first direction, while they are being pressed in the first direction.

[0007] The invention is based on the objective of providing a cell block for an electric battery that is improved compared to the prior art.

[0008] The problem is solved according to the invention by a cell block which has the features specified in claim 1.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] The cell block for an electric battery comprises a plurality of electrically interconnected individual cells, each of which is held in a shell- and / or frame-shaped holding element made of plastic, and at least one clamping element by means of which the individual cells are clamped together.

[0011] According to the invention, at least one metal heat-conducting plate, designed for coupling to a temperature control device, is arranged between each individual cell, and the retaining elements are mechanically connected to the at least one clamping element via the heat-conducting plates. Each heat-conducting plate is connected to a retaining element by a material-locking and / or form-locking connection, the heat-conducting plate being overmolded, at least partially, with the plastic of the retaining element. Furthermore, in a connection area provided for connection to the clamping element, the heat-conducting plate comprises at least one tab extending from the retaining element.

[0012] This prevents the force generated by the clamping element from being transferred directly and at a single point to the plastic retaining element, also known as the cell holder. The metal heat-conducting plates are mechanically highly resilient and distribute the forces introduced by the clamping element over a large area within the plastic of the retaining element. This creates a connection with high mechanical strength, which can be implemented in a particularly compact design.

[0013] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0014] This shows: Fig. 1 schematically a perspective view of a first embodiment of a heat-conducting plate for a single cell of a cell block, Fig. 2 schematically a perspective view of a first embodiment of a retaining element with a heat-conducting plate according to Fig. 1, Fig. 3 schematically a perspective view of two individual cells and the holding element according to Fig. 2 in the unassembled state, Fig. 4 schematically a perspective view of the two individual cells and the holding element according to Fig. 2 in the assembled state, Fig. 5 schematically depicts a cell cluster of several individual cells and holding elements according to Fig. 4 in the unassembled state, Fig. 6 schematically an exploded view of a first embodiment of a cell block with a cell cluster according to Fig. 5, Fig. 7 schematically a perspective view of a top side of the cell block according to Fig. 6 in the assembled state, Fig. Figure 8 schematically shows a perspective view of a bottom side of the cell block according to Fig. 6 in the assembled state, Fig. 9 schematically a perspective view of the cell block according to Fig. 7 as well as a temperature control device and a thermal conductivity film before assembly, Fig. 10 schematically a perspective view of a second embodiment of a cell block, Fig. 11 schematically a perspective view of a third embodiment of a cell block, Fig. 12 schematically a perspective view of a second embodiment of a heat-conducting plate and a second embodiment of a retaining element, Fig. 13 schematically a perspective view of a third embodiment of a heat-conducting plate and of the second embodiment of the retaining element, Fig. 14 schematically a perspective view of a fourth embodiment of a heat-conducting plate and a third embodiment of the retaining element, Fig. 15 schematically a perspective view of a fourth embodiment of a cell block with a plurality of individual cells as well as heat-conducting plates and retaining elements according to Fig. 14, Fig. 16 schematically a perspective view of a fifth embodiment of a heat-conducting plate and a fourth embodiment of the retaining element, Fig. 17 schematically a perspective view of a fifth embodiment of a cell block with a plurality of individual cells as well as heat-conducting plates and retaining elements according to Fig. 16 in an initial assembly state, Fig. 18 schematically a perspective view of the cell block according to Fig. 16 in a second assembly state, Fig. 19 schematically a perspective view of a sixth embodiment of a cell block as well as a temperature control device and a thermal conductivity film before assembly, and Fig. 20 schematically a perspective view of the cell block as well as the temperature control device and the thermal conductivity film after assembly.

[0015] Corresponding parts are marked with the same reference symbols in all figures.

[0016] In the Fig. Figures 1 to 8 show in different views a possible first embodiment of a cell block 1 according to the invention for an electric battery as well as components of the cell block 1.

[0017] The battery is, for example, a so-called high-voltage battery for vehicle applications, such as hybrid, plug-in or electric vehicles, or for stationary applications, such as power supplies or energy storage systems.

[0018] Such high-voltage batteries comprise at least one cell block 1, which includes a plurality of electrochemical individual cells 2 connected electrically in series and / or parallel. The individual cells 2, arranged at each end of the cell block 1, are electrically connected to a current collector plate 8, which serves as the high-voltage contact of the cell block 1 and can be coupled to the battery's terminal contacts. The current collector plates 8 are, for example, made of plastic, into which solid busbars with high-voltage contacts are integrated, in particular injection-molded.

[0019] The individual cells 2 are so-called pouch cells or coffee bag cells, which are designed as flat cells and in which a cell housing 2.1 is formed from a film-like packaging. Flat cells, in this context, are understood to be individual cells 2 whose height and width are many times greater than their thickness.

[0020] The cell housing 2.1 comprises a composite film which includes a layer of aluminum foil as a diffusion barrier, so that no moisture or other foreign substances penetrate it and no electrolyte escapes to the outside over the lifetime of the individual cells 2. The aluminum foil is coated on both sides with a plastic, in particular a thermoplastic.

[0021] The cell casing 2.1 encloses an electrochemically active component (not shown in detail) and shields it from the environment. An electrochemically active part of the single cell 2 is an electrode arrangement, which is designed as a flat electrode stack or electrode winding. A flat design is understood to mean that the height and width of the electrode arrangement are many times greater than its thickness. The electrode stack or electrode winding is formed by several layers of cathode and anode foils, in particular coated aluminum and copper foils, each separated by a separator layer.

[0022] The anode and cathode layers of the electrode assembly are uncoated at least at one edge and protrude from the electrode stack or winding in the form of flags, where they are optionally connected to each other to form a package, for example, by tack welding. The flags form the electrical poles of the electrode assembly and are connected inside the individual cell 2 to flat, sheet-metal-shaped conductors 2.2, 2.3 that project through the cell housing 2.1. This connection is created by means of material-bonded press and / or fusion welding processes, such as resistance spot welding, vibration or ultrasonic welding, or laser welding, and / or by means of a force-fit connection, such as riveting, and / or by means of a form-fit connection, such as clinching or toxing.

[0023] The surge arresters 2.2 and 2.3 are electrically insulated and routed through the cell housing 2.1 to the outside to allow current input and output. In one possible embodiment, a surge arrester 2.2 located at the positive terminal is made of aluminum, and a surge arrester 2.3 located at the negative terminal is made of copper.

[0024] The arresters 2.2, 2.3 run with their flat sides essentially perpendicular to the flat sides of the individual cell 2, so that a simple electrical interconnection of adjacent individual cells 2 is possible, for example by welding and / or pressing the arresters 2.2, 2.3 bent directly on top of each other.

[0025] After arranging the electrodes within the cell housing 2.1 and filling it with an electrolyte, two opposing and essentially parallel films are joined together at their edges and around the perimeter. This is achieved by partially melting a layer or coating applied to the inner surfaces of the films and subsequently allowing the coating to solidify, creating a perimeter seal.

[0026] Due to the relatively low rigidity of the cell housing 2.1, the individual cells 2 are each held in a double-shell-shaped retaining element 5, which surrounds the respective individual cell 2 at least on its edges and is made of plastic for electrical insulation. Alternatively, a shell-shaped and / or frame-shaped design of the retaining element 5 is also possible.

[0027] Temperature control of the individual cells 2, i.e., cooling or heating, takes place within the battery by means of a Fig. 9. The plate-shaped temperature control device 3, which is shown in more detail below, is permeable to a temperature control medium, such as water, a refrigerant from a vehicle air conditioning system, or air. For reasons of installation space, the temperature control device 3 is arranged on one longitudinal side of the cell block 1 and is thermally coupled to the individual cells 2.

[0028] Since the cell housing 2.1 of the individual cells 2 designed as pouch cells has a relatively low thermal conductivity, at least one heat-conducting plate 4 for coupling with the temperature control device 3 is arranged between the individual cells 2.

[0029] This heat-conducting plate 4, made of a metal with high thermal conductivity, for example aluminum, is thermally coupled with its flat side to the flat sides of two adjacent individual cells 2, the individual cells 2 being, for example, bonded to the heat-conducting plate 4 with their flat sides. In a lower edge region 4.1 facing the temperature control device 3, the heat-conducting plate 4 is angled, in particular by 90°, to increase the heat transfer surface area.

[0030] The heat-conducting plate 4 is inserted centrally into the retaining element 5 between the two shells, acting as a base or partition, and is connected to the retaining element 5 by a material-locking and / or form-fit connection. The heat-conducting plate 4 is at least partially overmolded with the plastic of the retaining element 5.

[0031] To fix the individual cells 2 within the cell block 1, the individual cells 2 are clamped by means of four clamping elements 6 designed as angle profiles and, for example, aluminium, and so-called pressure glasses 7 arranged at the end of the cell block 1.

[0032] In order to prevent forces generated by the clamping elements 6 from being transferred directly and at a single point to the plastic retaining element 5, the retaining elements 5 are each mechanically connected to the clamping elements 6 via the associated heat-conducting plate 4.

[0033] For this purpose, the heat-conducting plates 4 have tabs 4.2 to 4.5 in the connection areas provided for connection with the clamping elements 6. These tabs extend from the retaining element 5 and are bent at an angle of 90°. The retaining elements 5 each have corresponding recesses A1 to accommodate the tabs 4.2 to 4.5.

[0034] In the illustrated first embodiment of the cell block 1, the heat-conducting plates 4 are materially bonded to the clamping elements 6 in the area of ​​the tabs 4.2 to 4.5, the material bond being created by welding between the tabs 4.2 to 4.5 and the clamping elements 6. Alternatively or additionally, bonding of the tabs 4.2 to 4.5 to the clamping elements 6 is also possible.

[0035] In the illustrated embodiment, welding is carried out by means of weld seams S, which are designed as fillet welds between an edge of the clamping elements 6 and the tabs 4.2 to 4.5 and are produced in a TIG welding process (TIG = Tungsten Inert Gas) or MIG welding process (MIG = Metal Inert Gas).

[0036] Fig. Figure 9 shows a perspective view of cell block 1 according to Fig. 7 as well as the plate-shaped temperature control device 3 and a thermal conducting film 9 arranged between a bottom of the cell block 1 and the temperature control device 3 before assembly.

[0037] In Fig. Figure 10 shows a perspective view of a second embodiment of cell block 1, in contrast to the one in Fig. In the first embodiment shown in Figure 7, the welds S are formed as lap welds on a surface of the clamping elements 6, penetrating them. The welds S are produced, for example, using a laser welding process.

[0038] Fig. Figure 11 shows a perspective view of a third embodiment of cell block 1, wherein, in contrast to the one in Fig. In the first embodiment of cell block 1 shown in Figure 7, the welds S are formed as fillet welds between the edge areas of oval recesses A2 of the clamping elements 6, also referred to as stadium-shaped, and the tabs 4.2 to 4.5.

[0039] Fig. Figure 12 shows a perspective view of a second embodiment of the heat-conducting plate 4 and a second embodiment of the retaining element 5.

[0040] The heat-conducting plate 4 is formed from a trimmed extruded profile, with the tabs 4.2 to 4.5 having a T-shaped cross-section, which increases the welding surface. The recesses A1 of the retaining element 5 are formed corresponding to the tabs 4.2 to 4.5.

[0041] In Fig. Figure 13 shows a perspective view of a third embodiment of the heat-conducting plate 4 and of the second embodiment of the retaining element 5.

[0042] Unlike the one in Fig. In the second embodiment of the heat-conducting plate 4 shown in Figure 12, this is initially formed as a flat sheet, whereby the tabs 4.2 to 4.5, which have a T-shaped cross-section, are folded several times.

[0043] The Fig. 14 and Fig. Figure 15 shows a perspective view of a fourth embodiment of the heat-conducting plate 4 and a third embodiment of the retaining element 5, as well as a perspective view of a fourth embodiment of the cell block 1 with a plurality of individual cells 2 and the heat-conducting plates 4 and retaining elements 5 according to Fig. 14.

[0044] Unlike the one in Fig. In the first embodiment of cell block 1 shown in Figure 7, the heat-conducting plates 4 are screwed to the clamping elements 6. For this purpose, the recesses A2 in the clamping elements 6 are designed such that a metric screw 11 can be guided through them, which engages in corresponding threads 10 formed on the tabs 4.2 to 2.5. The threads 10 are realized by means of rivet nuts or weld nuts. Alternatively, a threaded through-hole or fixation by means of self-tapping screws 11 is also possible.

[0045] In the Fig. 16 and Fig. Figure 17 is a perspective view of a fifth embodiment of the heat-conducting plate 4 and a fourth embodiment of the retaining element 5, as well as a perspective view of a fifth embodiment of the cell block 1 with a plurality of individual cells 2 and the heat-conducting plates 4 and retaining elements 5 according to Fig. 16 shown in a first and a second assembly state.

[0046] Unlike the one in Fig. In the first embodiment of cell block 1 shown in Figure 7, the tabs 4.2 to 4.5 are guided through slot-shaped recesses A1 of the retaining elements 5 and through similarly slot-shaped recesses A2 of the clamping elements 6 and bent over onto the clamping elements 6. Furthermore, the tabs 4.2 to 4.5 are welded to the clamping elements 6 by means of overlapping welds S. The welds S are produced, for example, using a laser welding process.

[0047] In an embodiment not shown, the weld seams S are omitted.

[0048] The Fig. 18 and Fig. Figure 19 shows a sixth embodiment of the cell block 1, the temperature control device 3 and the thermal conductivity film 9 in a perspective view before and after assembly.

[0049] Unlike the one in Fig. 7 first embodiment of cell block 1 and the representation in Fig. 9 The plate-shaped temperature control device 3 on the underside of the cell block 1 simultaneously forms a clamping element 6, wherein the temperature control device 3 is welded to the edge regions 4.1 of the heat-conducting plates 4 by means of welds S. The welds S are designed as fillet welds between an edge of the temperature control device 3 and the edge regions 4.1 of the heat-conducting plates 4 and are produced in a TIG welding process or a MIG welding process.

[0050] All previously mentioned embodiments of the cell block 1 and its components are also applicable if the retaining elements 5 are each formed solely by a correspondingly shaped heat-conducting plate 4 and the overmolding with the plastic is omitted. Reference symbol list 1 cell block 2 single cells 2.1 Cell casing 2.2 Surge arresters 2.3 Surge arresters 3 Temperature control device 4 Heat-conducting plates 4.1 Edge area 4.2 Tab 4.3 Tab 4.4 Tab 4.5 Tab 5 retaining element 6 clamping element 7 pressure glasses 8 Current collector plate 9 Thermal conductivity film 10 threads 11 screw A1 recess A2 recess S weld seam

Claims

[1] Cell block (1) for an electric battery with - a plurality of electrically interconnected individual cells (2), - which are each held in a shell- and / or frame-shaped holding element (5) made of plastic, and - at least one clamping element (6) by means of which the individual cells (2) are clamped together, characterized by , that - between the individual cells (2) there is arranged at least one heat conducting plate (4) made of metal and intended for coupling to a temperature control device (3), - the holding elements (5) are mechanically connected to the at least one clamping element (6) via the heat conducting plates (4), - a heat conducting plate (4) is connected in a material and / or form-fitting manner to a holding element (5), wherein the heat conducting plate (4) is at least partially overmolded with the plastic of the holding element (5), and - the heat conducting plate (4) comprises at least one tab (4.2 to 4.5) in a connecting region provided for connection to the clamping element (6), which tab is led out of the holding element (5). [2] Cell block (1) according to claim 1, characterized by that the heat conducting plates (4) are integrally connected to the at least one clamping element (6). [3] Cell block (1) according to one of the preceding claims, characterized by that the heat conducting plates (4) are screwed to the at least one clamping element (6). [4] Cell block (1) according to claim 3, characterized by that the heat conducting plates (4) each have a thread (10) in a connecting area provided for connection to the at least one clamping element (6), into which thread a screw (11) guided through a recess (A2) of the clamping element (6) can be screwed. [5] Cell block (1) according to one of the preceding claims, characterized bythat the heat conducting plates (4) are positively connected to the at least one clamping element (6). [6] Cell block (1) according to one of the preceding claims, characterized by that the at least one tab (4.2 to 4.5) is guided through a slot-shaped recess (A2) of the clamping element (6) corresponding thereto and is bent on a side of the clamping element (6) facing away from the holding element (5).

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