Cell lid for a prismatic cell and electrochemical energy storage device with such a cell lid

Abstract

Cell cover for a prismatic cell, in particular a lithium-based cell, comprising a cover plate (6) with a bottom (6d), a top (6e) and at least one current-conducting recess (6a, 6b), two electrical terminals (2, 4) arranged on the top (6e), a first and a second current clamp (1, 3) which can be connected to the cover plate (6) in a connection area arranged on the bottom (6d), wherein an electrical conductor (2a, 4a) is arranged in the current-conducting recess (6a, 6b) with which the electrical terminal (2, 4) and the current clamp (1, 3) can be contacted, wherein the cover plate (6) has a connection recess (6c) spaced apart from the current-conducting recess (6a, 6b) in at least one of the connection areas, wherein at least one of the current clamps (1, 3) is positively engaged with the connection recess (6c) The cover plate (6) is connectable, wherein the cover plate (6), in particular in the section,in which the connection area is arranged on the underside (6d), has an at least substantially flat top surface (6e) and, wherein at least one of the connection recesses (6c) extends to the edge of the cover plate (6) and is an open-edge recess, characterized in that the current bracket (1, 3) can be connected to an adapter plate (5a, 5b), that the cover plate (6) can be positively connected to the adapter plate (5a, 5b) in the connection area and that the adapter plate (5a, 5b) has an adapter recess (5a.1) for receiving the current bracket (1, 3), and that the adapter recess (5a.1) has a T-shaped form.

Description

[0001] The invention relates to a cell lid with current clamp for prismatic cells according to the preamble of the independent claim.

[0002] Such a device is known from publication US 2012 148 909 A.

[0003] The invention is described below in connection with an electrochemical energy storage cell for a mobile application, in particular as an energy storage device for a drive motor in a motor vehicle; this is not to be understood as a limitation of the invention to such an application.

[0004] High demands are placed on the energy density of energy storage cells for mobile applications, as the energy density, and thus the weight of the energy storage device, has a significant impact on its usability. An energy storage cell comprises an electrochemically active part, in which energy can be stored directly (so-called cell stack or cell winding), and a passive part. The passive part of the energy storage device includes, among other things, the housing and electrical conductors for supplying and removing electrical charge to and from the active part. Increasing the power density of an energy storage cell can be achieved, in particular, by improving the cell chemistry or by reducing the space required for the passive part.

[0005] US patent 2012 148 909 A discloses an energy storage cell in which current clamps are connected to the cell lid in a form-fitting manner. The cell lid has a curved surface into which the current clamp can be inserted at its upper end.

[0006] It is an object of the invention to provide an improved cell lid with a current clamp for a prismatic cell. This object is achieved by an object according to claim 1; preferred embodiments of the invention are the subject of the dependent claims.

[0007] A cell cover is designed to accommodate at least one, but preferably two, current contacts and electrical connections to enable electrical contact with the electrochemical storage cell. A current contact, as defined in the invention, is a device that electrically contacts a prismatic energy storage cell and conducts current to or from this cell. In particular, such an energy storage cell is designed as a stacked, folded, or so-called jellyroll cell and has a cuboidal plan, unlike a substantially cylindrical storage cell. Such cuboidal cells can also be referred to as pouch or coffee bag cells. This category also includes, in particular, cells of this geometric shape with metal or plastic housings, or with housings made of at least these two materials, so-called hybrid housings.

[0008] In connection with this invention, the terms cell stack and cell coil are used equivalently since, in particular, the type of layering of the anodes / cathodes, especially (layered, stacked or coiled), is of minor importance for the invention.

[0009] The current holder is preferably connectable to an electrical connection, wherein the electrical connection is configured for external contact with the storage cell and is particularly designed as the so-called pole of the storage cell. "Inside" here refers to the cell stack (anode-cathode layering). This cell stack is contained within a casing or housing, and the environment surrounding this housing or casing is to be understood as the "outside".

[0010] Furthermore, the cell lid has a cover plate with a bottom and a top surface. At least one, but preferably two, of the electrical connections are arranged on the top surface of the cover plate. In particular, one, but preferably two, of the current clamps are arranged on the underside of the cover plate.

[0011] This cover plate has a current-conducting recess. The current clamp can be connected through this current-conducting recess to an electrical conductor or an electrically conductive section with the electrical connection on the top of the cover plate.

[0012] The cover plate has a connection area for linking, in particular for mechanical connection, with the current clamp. The current-conducting recess is arranged in this connection area. The current-conducting recess extends from the underside to the top side of the cover plate. According to the invention, the cover plate has at least one connecting recess in addition to the current-conducting recess. Preferably, this connecting recess is spaced apart from the current-conducting recess. More preferably, at least one of the current clamps can be positively connected to the cover plate in the connecting recess.

[0013] Such a positive-locking connection between the current clamp and the cover plate also includes an indirect connection. Preferably, an indirect connection is a connection via an intermediate or adapter piece, so that the cover plate is not directly contacted by the current clamp, at least in some sections.

[0014] Preferably, the cover plate, particularly in the section opposite the connection area on the underside, has an at least substantially flat or planar upper surface. Preferably, the opposite area is understood to be at least the area directly opposite the underside. Preferably, the distance between the underside of the cover plate, at least in the area directly surrounding the connection area, and the plane within the connection area, which is designed for direct or indirect contact of the current clamp, is less than twice, preferably less than 1.5 times, and more preferably less than 1 time the wall thickness of the cover plate in the connection area.

[0015] Preferably, the cover plate according to the invention is to be understood as a thin-walled, elongated component. Preferably, the cover plate is designed as a sheet metal component, particularly one with thin walls. More preferably, the cover plate comprises aluminum or a steel material as a component or consists of such a material. In particular, the fact that the cover plate has a flat top surface in the vertical direction reduces the installation space required in this vertical direction.

[0016] Cell covers are known from the prior art which have a three-dimensional deformation of the cover plate in the connection area between the cover plate and the current clamp to create a positive-locking connection between the current clamp and the cover plate. According to the invention, a positive-locking connection between the current clamp and the cover plate is achieved by means of a connecting recess without the need for three-dimensional deformation of the cover plate; in particular, this results in an improved energy storage cell.

[0017] For the purposes of the invention, a prismatic cell is understood to be, in particular, a lithium-based energy storage cell, especially a lithium-ion energy storage cell. This storage cell is preferably characterized by its structural design. With regard to its structural design, a distinction is made, at least essentially, between cylindrical rolled storage cells and prismatic folded, layered storage cells and so-called jellyroll cells. The invention preferably relates to essentially cuboid or prismatic storage cells.

[0018] For the purposes of the invention, the electrical connections of the positive and negative poles of the energy storage cell are to be understood as those for delivering or receiving electrical power outside the energy storage cell.

[0019] For the purposes of the invention, the current clamp is understood to be a device that, on the one hand, electrically contacts the prismatic cell and, on the other hand, delivers or receives the electrical charge to the electrical terminals. More preferably, such a current clamp has at least one, but preferably two, conductor arms. These conductor arms are further preferably configured for electrically contacting the prismatic cell. More preferably, the current clamp has a contact surface facing the cover plate. Preferably, the current clamp has a U-shaped cross-section, in which the conductor arms form the legs of the U and the contact surface section connects the two conductor arms. Particularly during assembly, the current clamp can rotate relative to the cover plate. This is prevented by the positive-locking connection between the current clamp and the cover plate according to the invention.

[0020] Preferably, the current clamp is made of an aluminum alloy or at least contains aluminum as a component. More preferably, a second current clamp contains copper as a component or is made entirely of copper. The use of copper and aluminum for the current clamps has proven advantageous because they exhibit both good electrical conductivity and good formability.

[0021] In a preferred embodiment, the current clamp can be connected to the cover plate indirectly. For the purposes of the invention, an indirect connection of the current clamp to the cover plate means that the current clamp contacts an adapter plate and the adapter plate contacts the cover plate. Preferably, the adapter plate includes an insulating material or consists of such an electrically insulating material. Preferably, the current is conducted from the current clamp to the electrical connection via the electrical conductor, which extends through the current-conducting recess. The electrical conductor can be metallurgically bonded to both the current clamp and the electrical connection. More preferably, the electrical conductor is formed integrally with the electrical connection.In particular, by defining an electrical conductor via this electrical conductor between the current bracket and the electrical connection, leakage currents between the cover plate and the current bracket can be advantageously prevented.

[0022] In a preferred embodiment, the cover plate has a wall thickness T in a section where the connection area is located. The connection recess for receiving the current clamp in the cover plate has a depth t. Preferably, the depth t is less than the wall thickness T. Preferably, the connection recess is designed as a pocket in the cover plate. More preferably, a pocket is understood to be a recess that does not completely penetrate the cover plate. More preferably, a connection recess can be formed in the cover plate by a forming process. In particular, a non-through connection recess only minimally affects the strength and stiffness of the cover plate, and the current clamp can be securely received on the cover plate.

[0023] In a preferred embodiment, the cover plate has a wall thickness T in the section where the connection area is located. The recess for receiving the current clamp has a depth t. Preferably, this depth t is equal to the wall thickness T. In particular, because the depth t and the wall thickness T are equal, the connection recess extends completely through the cover plate. Preferably, the connection recess is designed as an opening in the cover plate. More preferably, the connection recess extends from the underside to the top side of the cover plate. A connection recess that completely penetrates the cover plate, in particular, enables a particularly secure hold of the current clamp on the cover plate.

[0024] In a preferred embodiment, the current clamp has an electrically insulating coating in the section where it contacts the cover plate or the adapter plate. Preferably, this electrically insulating coating can be bonded to the current clamp by a material bond. More preferably, such an electrically insulating coating is to be understood as a coating of a plastic, in particular plastic granules, or as a type of paint.

[0025] In particular, improved electrical insulation between the current bracket and the cover plate can be achieved by applying an electrically insulating coating in the contact area between the current bracket and the cover plate or between the current bracket and the adapter plate.

[0026] In a preferred embodiment, at least one of the electrical connections is connectable to the current clamp. This electrical connection is more preferably electrically insulated from the cover plate. An insulating material is more preferably arranged between the electrical connection and the cover plate for this electrical insulation. The electrical connection and the current clamp are more preferably metallurgically bonded to each other. The electrical connection more preferably has an electrical conductor that extends through the current recess in the cover plate, and this electrical conductor is preferably metallurgically bonded to the electrical connection or, more preferably, formed integrally with it. Several of the electrical connections are more preferably electrically insulated from the cover plate.In particular, by electrically insulating the electrical connections from the cover plate, leakage currents between the electrical connections and the cover plate can be prevented, or the cover plate can be kept free of electrical voltages.

[0027] In a preferred embodiment, at least one of the current clamps comprises copper or a copper alloy as a component, or consists entirely of these materials, and the electrical connection connectable to this current clamp comprises aluminum or an aluminum alloy as a component, or consists entirely of these materials. Preferably, the current clamp and the electrical connection can be joined by a material-fit or form-fit connection. Preferably, a material-fit connection is implemented as a welded or soldered joint. In particular, the use of a copper / aluminum material mix makes it possible to adapt the electrical connection and the current clamp to the respective requirements. Especially an aluminum / aluminum or copper / copper connection enables a particularly secure connection of the current clamp to the electrical connection.

[0028] In a preferred embodiment, the current holder has a contact surface configured to mechanically contact the cover plate or the adapter plate. Furthermore, the current holder has at least one conductor arm configured to electrically contact the electrochemical storage cell. The conductor arm preferably contacts the electrochemical storage cell within a conductor section. The current holder extends, in particular, from the contact surface at an angle of at least approximately 90°, or orthogonally to this surface.

[0029] The current clamp preferably has at least two conductor arms which form a U-shaped cross-section with the contact surface. A distance K between an end of the conductor section facing the contact surface and the contact surface is preferably ≥ 1 time the wall thickness L of the current clamp in the area of ​​the contact surface. Preferably, the distance K is > 2 times L, more preferably > 3 times L, and particularly preferably > 4 times L. Furthermore, the distance K is < 15 times L, more preferably < 12 times L, more preferably < 10 times L, and particularly preferably < 8 times L. It has been found that an insufficient distance K can lead to problems with contacting the electrochemical storage cell via the conductor arm, while a large distance K, on ​​the other hand, leads to an increased space requirement.In particular, choosing the distance K from the described range leads to good contact of the electrochemical storage cell by the conductor arm on the one hand and to a small installation space requirement on the other.

[0030] In a preferred embodiment, the cover plate has several connection recesses. Preferably, the cover plate has two or more connection recesses. More preferably, the connection recesses are symmetrically spaced from or arranged symmetrically to the current-carrying recess. Preferably, the connection recesses are located in an edge region of the contact surface between the current clamp and the cover plate, or between the cover plate and the adapter plate. In particular, a symmetrical arrangement of two or more connection recesses allows for particularly simple assembly of the current clamp.

[0031] Preferably, the connection recesses are arranged asymmetrically. In particular, an asymmetrical arrangement or design of the connection recesses enables a unique assignment of the current clamp (positive / negative pole) to the cover plate.

[0032] In a preferred embodiment, the adapter plate has an adapter recess for receiving the current clamp. More preferably, the adapter plate has projections or extensions opposite the side with the adapter recess, which are designed to engage in the connecting recess on the cover plate.

[0033] Preferably, the adapter recess has a T-shaped form. Preferably, the adapter recess is understood to be a recess that extends completely through the adapter plate; more preferably, the adapter recess is understood to be a recess that does not extend completely through the adapter plate. In particular, a T-shaped design of the adapter recess enables, on the one hand, secure fixation of the current clamp to the adapter plate and, on the other hand, a clear assignment of the current clamp to the adapter plate.

[0034] In a preferred embodiment, at least one of the connecting recesses, preferably several or all, extends to the edge of the cover plate. In particular, such connecting recesses are to be understood as edge-open recesses. Preferably, such an edge-open connecting recess thus extends from within the cover plate to its edge.

[0035] Further embodiments and features of the invention are illustrated in the following, partially schematic, figures. These show:

[0036] Fig. 1: a perspective exploded view of the cell lid according to the invention,

[0037] Fig. 2: A detailed view of a cover plate with an adapter plate,

[0038] Fig. 3: a perspective view of a cell lid according to the invention.

[0039] Fig. Figure 1 shows an exploded view of a cell lid according to the invention. The base plate 6 has a top 6e and a subpage 6d open. The electrical connections 2 , 4 are on the top 6e arranged. These electrical connections 2 , 4 Each electrical conductor 2a , 4a up. The electrical conductors 2a , 4aare through the current conductor recess 6a and 6b through the cover plate 6 guided. On the underside of the cover plate 6d are the power bars 1 , 3 arranged.

[0040] The power bars 1 , 3 contact the cover plate 6 not directly, but each time via an adapter plate 5a , 5b The adapter plates 5a , 5b Each forms a positive connection with the cover plate 6 out. The adapter plates are used for this purpose. 5a , 5b into the connecting recesses 6c one. The current bar 1 It consists of an aluminum-based alloy. The current bracket 3 It contains copper as a component, or rather, consists of it. The conductor arms 1a , 1b , 3a , 3b extend from the respective cover surfaces 1c , 3c, in the orthogonal direction.

[0041] These contact surfaces are located on the inner sides of the conductor arms. 1d , 3d for the electrical contacting of the electrochemical storage cell (not shown). The opposing conductor arms have... 1a , 3a There are also contact surfaces, which are not visible in the illustration shown. In the area of ​​the top surface 1c , 3c The conductor arms have a wall thickness L. The area for contacting the electrochemical storage cell on the conductor arms extends to its end facing the top surface. 1e , 3e . Between the top surface 1c , 3c and the respective end 1e , 3e The distance K is established. The electrical connections are each encased in an electrically insulating sheath. 7a , 7b surrounded. This coating achieves 7a ,7b also through the power line opening 6a , 6b through it.

[0042] In Fig. Figure 2 is a perspective view of the connection area between the top plate 6 and the adapter plate 5a As shown. The statements also apply analogously to the connection area between the cover plate. 6 and the adapter plate 5b The adapter plate 6 has two connecting recesses 6c open. The connecting recesses 6c are excluded from the power supply agreement 6a spaced apart and arranged symmetrically to it. The connecting recesses 6c are open-edged recesses in the cover plate 6 arranged. The adapter plate 5a has a T-shaped recess 5a.1 for mounting a current bracket 1 (not shown) on.

[0043] On the opposite side from the recess5a.1 The adapter plate is designed to accommodate a current bracket. 5a Surveys 5a.2 The surveys are... 5a.2 for a form-fitting connection with the recesses 6c set up. The recesses 6c in the top plate 6 have a depth t. The cover plate 6 indicates in the area where these are connected to the current bracket and therefore also to the adapter plate 5a It can be connected, with a wall thickness T. The connection recess 6c does not extend completely through the top plate 6 The adapter plate 5a is on the underside of the cover plate 6d arranged. The top of the cover plate 6e exhibits a flat profile, at least in the connection area with the adapter plate.

[0044] In Fig. Figure 3 shows an assembled cell lid in perspective view. The cell lid has a cover plate. 6with a top 6e and a subpage 6d on. The cover plate has 6 in the area of ​​electrical connections 2 , 4 a flat surface 6e up. The power bars 1 , 3 Each has two conductor arms 1a , 1b , 3a , 3b up. The power bar 1 , which is made of aluminum alloy, is used in the electrical connection field 10 electrically conductive with the cover plate 6 connected. Furthermore, the current bracket is 1 via the adapter plate 5a form-fitting with the cover plate 6 connected. The current bracket 3 is via the adapter plate 5b with the cover plate 6 connected. The electrical connections 2 , 4 are on the top 6e the cover plate 6 arranged in the area 11 The power bar indicates3 no electrically conductive connection to the cover plate 6 on. QUOTES INCLUDED IN THE DESCRIPTION

[0045] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0046] US 2012148909 A [0002, 0005]

Claims

[1] Cell lid for a prismatic cell, in particular a lithium-based cell with a cover plate ( 6 ) with a subpage ( 6d ), a top side ( 6e ) and at least one current-carrying recess ( 6a , 6b ), two electrical connections ( 2 , 4 ), which are located on the top ( 6e ) are arranged, a first and a second current bar ( 1 , 3 ), which is connected to the cover plate ( 6 ) in each connection area, which is located on the underside ( 6d ) is arranged, are connectable, where in the current-carrying recess ( 6a , 6b ) an electrical conductor ( 2a , 4a ) is arranged, with which the electrical connection ( 2 , 4 ) and the current bracket ( 1 , 3 are contactable, characterized by that the cover plate (6 ) in at least one of the connection areas a recess from the current conductor ( 6a , 6b ) spaced connection recess ( 6c ) shows, that at least one of the power bars ( 1 , 3 ) in the connecting recess ( 6c ) form-fitting with the cover plate ( 6 ) connectable, that the cover plate ( 6 ), in particular in the section where the connection area is located on the underside, an at least substantially flat top surface ( 6e ) exhibits. [2] Cell lid according to claim 1, characterized by that the current bar ( 1 , 3 ) with an adapter plate ( 5a , 5b ) connectable, that the cover plate ( 6 ) with the adapter plate ( 5a , 5b ) can be positively connected in the connection area. [3] Cell lid according to claim 1, characterized bythat the cover plate ( 6 ) in the section where the connection area is located, has a wall thickness T, that the connection recess ( 6c ) to accommodate the current bracket ( 1 , 3 ) or the adapter plate ( 5a , 5b ) has a depth t and, that t is smaller than T. [4] Cell lid according to claim 1, characterized by that the cover plate in the section where the connection area is located has a wall thickness T, that the connection recess ( 6c ) to accommodate the current bracket ( 1 , 3 ) or the adapter plate ( 5a , 5b ) has a depth t and that t is the same size as T. [5] Cell lid according to any one of the preceding claims, characterized by that at least one of the power bars ( 1 , 3 ) in the section where it contacts the cover plate (1c , 3c ) has an electrically insulating coating. [6] Cell lid according to claim 5, characterized by that one of the electrical connections ( 2 , 4 ) with the current bracket ( 1 , 3 ) connectable, that the electrical connection ( 2 , 4 ) is electrically insulated from the top plate, that the connection ( 2 , 4 ) and the current bracket ( 1 , 3 ) are able to be bonded together in a material-bonded manner. [7] Cell lid according to any one of the preceding claims, characterized by that at least one of the power bars ( 1 , 3 ) contains or consists of copper or a copper alloy as a component and that the current-breaking device with this current-breaking device ( 1 , 3 ) connectable electrical connection as having or consisting of aluminium or an aluminium alloy as a component. [8] Cell lid according to any one of the preceding claims, characterized by that the current bar ( 1 , 3 ) a contact cover surface ( 1c , 3c ) has, with which the cover plate ( 6 ) or the adapter plate ( 5a , 5b ) is mechanically contactable and at least one ladder arm ( 1a , 1b , 3a , 3b ), which extends from the contact cover surface ( 1c ) extends in an orthogonal direction to this, that the current bar ( 1 , 3 ) in the area of ​​the contact cover surface ( 1c ) has a wall thickness L, that the ladder arm ( 1a , 1b , 3a , 3b ) is set up in a conductor section for the electrical contacting of the prismatic cell, that the distance K between the end facing the contact surface ( 1e , 3e) of the conductor section and the contact cover surface ( 1c , 3c ) greater than or equal to 1 time L, preferably greater than 2 times L, preferably greater than 3 times L and particularly preferably greater than 4 times L and Furthermore, the distance K is less than 15 times L, preferably less than 12 times L, preferably less than 10 times L and particularly preferably less than 8 times L. [9] Cell lid according to any one of the preceding claims, characterized by that the cover plate ( 6 ) several connecting recesses ( 6c ) has, preferably two or more. [10] Cell lid according to claim 2, characterized by that the adapter plate ( 5a , 5b ) an adapter recess ( 5a.1 ) to accommodate the current bracket ( 1 , 3 ) shows that the adapter recess ( 5a.1 ) has a T-shaped form. [11] Cell lid according to any one of the preceding claims, characterized bythat at least one of the connection openings ( 6c ) to the edge of the cover plate ( 6 ) extends, in particular a recess open at the edge. [12] Electrochemical energy storage device with at least one cell cover according to one of the preceding claims, in particular accumulator with a plurality of such cell covers.

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