Housing part for an electrical storage device and electrical storage device

Description

[0001] The invention relates to a housing part for an electrical storage device, in particular a battery or a capacitor, comprising a base body and at least one first connection terminal arrangement with a connection pin, which is guided through a through-opening of the base body and is fixed in the through-opening in an electrically insulated manner via a fixing material, wherein the connection pin protrudes beyond the through-opening on at least one side thereof. A further aspect of the invention relates to an electrical storage device comprising a housing with such a housing part.

[0002] Electrical storage devices such as batteries or capacitors typically comprise a housing and at least one storage cell. The housing encloses the storage cell and provides connection terminals for electrically connecting the storage device.

[0003] Batteries, within the meaning of the invention, include both disposable batteries, which can be disposed of and / or recycled after discharge, and accumulators. Accumulators, preferably lithium-ion batteries, are intended for various applications such as portable electronic devices, mobile phones, power tools, and, in particular, electric vehicles. These batteries can replace traditional energy sources such as lead-acid batteries, nickel-cadmium batteries, or nickel-metal hydride batteries. The batteries can also be used in sensors or in the Internet of Things.

[0004] Storage devices within the meaning of the invention also include capacitors, in particular supercapacitors.

[0005] Supercapacitors, also called supercapacitors, are commonly known electrochemical energy storage devices with particularly high power density. Unlike ceramic, film, and electrolytic capacitors, supercapacitors do not have a dielectric in the conventional sense. They implement the storage principles of static storage of electrical energy through charge separation in a double-layer capacitor, as well as electrochemical storage of electrical energy through charge exchange using redox reactions in a pseudocapacitor.

[0006] Supercapacitors include, in particular, hybrid capacitors, especially lithium-ion capacitors. Their electrolyte typically comprises a solvent in which conductive salts, usually lithium salts, are dissolved. Supercapacitors are preferably used in applications requiring a high number of charge / discharge cycles. Supercapacitors are particularly advantageous in the automotive sector, especially in the field of braking energy recuperation. Other applications are, of course, also possible and encompassed by the invention.

[0007] Lithium-ion batteries have been known as storage devices for many years. For more information, see "Handbook of Batteries," David Linden, editor, 2nd edition, McCrawhill, 1995, chapters 36 and 39.

[0008] Various aspects of lithium-ion batteries are described in a variety of patents.

[0009] For example: US 961,672 A1, US 5,952,126 A1, US 5,900,183 A1, US 5,874,185 A1, US 5,849,434 A1, US 5,853,914 A1, and US 5,773,959 A1.

[0010] Lithium-ion batteries, especially for applications in automotive environments, typically comprise a multitude of individual battery cells connected in series and / or in series. The battery cells connected in series are combined to form so-called battery packs, and several battery packs are then combined to form a battery module, also known as a lithium-ion battery. Each individual battery cell has electrodes that extend from a battery cell casing. The same applies to supercapacitor casings.

[0011] Especially for the application of lithium-ion batteries in the automotive environment, a variety of problems must be solved, such as corrosion resistance, crash resistance, and vibration resistance. Another issue is sealing, especially hermetic sealing, over a long period of time.

[0012] US 2019 / 237740 A1 describes a battery with an electrode arrangement arranged in a housing, wherein a cover covers a housing opening. The cover has a through-opening through which a shaft of an inner terminal is passed and held in the through-opening in an electrically insulating manner by a multi-part plastic seal. On at least one side of the through-opening, another terminal with a sleeve is provided, which has a through-opening, wherein a protruding part of the shaft engages in the sleeve. The sleeve and shaft are joined together by pressure welding in that the sleeve is deformed, while at the same time an insulating element arranged between the cover and the sleeve is clamped.

[0013] EP 2 876 708 A1 discloses a housing part with a terminal arrangement similar to that in US 2019 / 237740 A1. Preformed seals are inserted between the terminals and the housing part for mechanical sealing. An insulation element is arranged between the terminal and the housing part.

[0014] In addition, to achieve high storage density, it is desirable to reduce the proportion of passive components such as the housing in the overall structure of a storage device. Accordingly, housings with low material thicknesses are preferred. Examples of housings for electrical storage devices designed for the smallest possible height and low material thickness are known, for example, from DE 10 2014 016 601 A1 and WO2020 / 104571 A1.

[0015] A disadvantage of the known housings for electrical storage devices, however, is that the thin material thickness of the housings can lead to deformation under high internal pressures. Such deformations are particularly undesirable in the area of ​​the covers, where the electrical feedthroughs and connection terminals are typically located.

[0016] It is therefore an object of the invention to provide a housing part, in particular a cover part, which is particularly pressure-resistant and rigid while maintaining a particularly compact design. Disclosure of the invention

[0017] A housing part for an electrical storage device, in particular a battery or a capacitor, is proposed. The housing part comprises a base body and at least one first connection terminal arrangement with a connection pin, which is guided through a through-opening of the base body and is fixed in the through-opening in an electrically insulated manner by a fixing material, wherein the connection pin protrudes beyond the through-opening on at least one side thereof.Furthermore, it is provided that at least on one side of the through-opening a connection pad is provided, which has an opening which is designed as a through-opening or as a blind hole, wherein the protruding part of the connection pin engages in the opening and is electrically connected to the at least one connection pad in the region of this opening, and wherein the at least one connection pad is fastened to the base body in an electrically insulating manner using an insulating material, wherein the insulating material is an electrically insulating adhesive or an electrically insulating casting material.The fixing material is selected from a glass or a glass ceramic, and the connection between the fixing material and the connecting pin as well as between the fixing material and the wall of the through-opening is hermetically sealed, wherein a first thermal expansion coefficient of the base body is greater than a second thermal expansion coefficient of the fixing material.

[0018] The housing part is designed to be joined with further housing parts to form a housing for an electrical storage device, wherein the housing part has the connection terminals of the storage device. Depending on the type of storage device, one or more connection terminals can be provided. For example, the storage device can comprise two first connection terminals, which can then serve, for example, as a positive terminal and a negative terminal. If the housing part comprises only a single first connection terminal arrangement, the base body of the housing part itself or a further housing part preferably represents a further connection terminal, for example a negative terminal or a ground terminal. In addition to the at least one first connection terminal arrangement, the housing part can also have one or more different further connection terminal arrangements.

[0019] The at least one connection terminal arrangement has a connection pin, which is guided through a through-opening of the base body and is held in this through-opening in an electrically insulating manner by a fixing material. The base body, the connection pin, and the fixing material form a metal-fixing material feedthrough, in which the fixing material seals against the connection pin and an inner wall of the through-opening. It is advantageous if the fixing material does not protrude beyond the through-opening, but is essentially flush with the through-opening or even slightly shorter than the length of the through-opening.

[0020] The connection between the fixing material and the connecting pin, as well as between the fixing material and the wall of the through-hole, is hermetically sealed. Hermetic sealing is understood in particular to mean that, at a pressure difference of 1 bar, the helium leak rate is preferably < 1 10 -7< mbar ls -1<, particularly preferably < 1 10 -8< mbar ls -1<, and most preferably < 1 10 -9< mbar ls -1<.

[0021] In the first connection terminal arrangement, the at least one connection pad represents a connection area to which electrical conductors can be connected to the first connection terminal arrangement. A connection pad arranged on an outer side of the housing part in the finished housing thus represents a connection area to which an electrical energy storage device encompassing the housing can be electrically contacted. A connection pad arranged on an inner side of the finished housing represents a connection area to which internal components such as storage cells, for example, a battery cell or a capacitor cell, can be connected.

[0022] In order to electrically connect at least one connection pad to the connection pin, these are arranged close to one another. For this purpose, the part of the connection pin that protrudes beyond the through-opening in the base body engages in the opening in the connection pad, regardless of whether the opening in the connection pad is designed as a through-opening or as a blind hole. Accordingly, when designed as a blind hole, the opening points towards the connection pin, whereby in this design variant the connection pin is covered by the connection pad. This advantageously ensures that the material of the connection pin is completely covered by the first connection terminal arrangement and is thus shielded, in particular, against influences from the environment or the media present inside the housing.

[0023] This arrangement also facilitates precise positioning of at least one connection pad during production, since the connection pin acts as a positioning aid to ensure accurate positioning of the connection pad.

[0024] In order to enable a good connection between the at least one connection pad and the connection pin, it is preferred that the connection pin protrudes at least 0.1 mm to 2 mm, particularly preferably 0.2 mm to 1 mm beyond the through-opening and thus beyond the base body.

[0025] The at least one first connection terminal arrangement can have exactly one connection pad. In an advantageous embodiment of the first connection terminal arrangement, the connection pad is located on a side of the housing part that is located on the outside in the finished housing. In an alternative advantageous embodiment of the first connection terminal arrangement, the connection pad is located on a side of the housing part that is located on the inside in the finished housing.

[0026] A particularly advantageous embodiment of the first connection terminal arrangement provides that in the finished housing, a connection pad is arranged on both the outer and the inner side of the housing part. This means that the first connection terminal arrangement can have a connection pad on both sides of the through-opening and thus on both sides of the housing part. In this case, it is preferred if the connection pin protrudes beyond the through-opening on both sides thereof and connection pads are arranged on both sides of the through-opening, each connection pad having an opening, wherein the protruding part of the connection pin engages in the respective opening and is electrically connected to the respective connection pad in the region of this opening.

[0027] The at least one connection pad is electrically connected to the connection pin. This connection can also represent a mechanical connection, so that the at least one connection pad is attached not only to the base body via the insulating material, but also to the connection pin. The insulating material is an electrically insulating adhesive or an electrically insulating cast material.

[0028] When using an adhesive as an insulation material, epoxy resins are particularly suitable. The adhesive can also be in the form of an adhesive tape, especially a double-sided adhesive tape. Thermoplastic or thermosetting plastics are particularly suitable as casting materials.

[0029] Insulating materials for external and internal connection pads can be different or the same. This allows adaptation to different requirements depending on the location of the connection pads.

[0030] When selecting a suitable adhesive, in particular a suitable epoxy resin or a suitable casting material, certain selection criteria play a role: Since processes such as soldering or welding can be used when assembling the housing part or the storage device, e.g. when creating a connection between a connection pin and a connection pad and / or a connection between a connection pad and connections such as connection lugs, it is advantageous if the adhesive is thermally resilient in order to be able to withstand the temperatures required for soldering or welding, at least for a short time. It is advantageous if the adhesive can be heated to temperatures of more than 150°C, preferably at least 220°C, at least for a short time, without the adhesive evaporating or degenerating, i.e. without there being a significant change in the initial adhesive strength.The term "short-term" here means a period of at least 1 minute to 5 minutes.

[0031] Alternatively, with regard to normal operation and possible accidents / malfunctions when using an electrical storage device, it may be advantageous if the adhesive is permanently thermally stable up to at least 80°C, preferably up to at least 100°C. Preferably, the adhesive is permanently thermally stable in the range from -40°C to +120°C, advantageously in the range from -40°C to +150°C.

[0032] According to a variant of the invention, adhesives are preferred which combine both properties with regard to thermal resistance, e.g. they are permanently thermally stable from -40°C to +150°C and can withstand short-term temperature loads of more than 150°C.

[0033] In addition to long-term and / or short-term temperature stability, the adhesive should also display good resistance to external influences, particularly liquids, aerosols and / or gases. Depending on the side of the housing part on which the connection pad is located in the finished housing, a distinction can be made between moisture resistance, also known as climate resistance or weather resistance, and chemical resistance, e.g. resistance to battery electrolytes: For the attachment of a connection pad that is arranged on an external side of the housing part in the finished housing, it is advantageous if the adhesive passes a temperature-humidity test. For this purpose, for example, a unit comprising a housing part with a connection terminal arrangement according to the invention with an adhesive-attached connection pad is exposed to a temperature of 85 °C and a relative humidity of 85% in a climatic chamber for 1000 hours.The unit is then subjected to mechanical stress, particularly gravity and bending loads, to determine the extent to which the initial bond strength is still present. The test is considered passed if the adhesive still retains at least 80% of its initial bond strength after the test.

[0034] For attaching a connection pad located on an inner side of the housing part in the finished housing, it is advantageous if the adhesive has sufficient resistance to electrolytes, conductive salts, etc. To determine resistance, the adhesive can, for example, be immersed in a test medium at 60°C for 20 days, and the medium can then be analyzed for components that have leached from the adhesive. Leaching is a measure of resistance to the respective medium. Furthermore, visible changes in the adhesive and / or medium, such as color changes, can provide information about resistance.

[0035] Since the conditions on the inside of the housing part are different from those on the outside, different adhesives, especially epoxy resins, can be used for the inside and outside to attach the connection pads.

[0036] However, an adhesive is preferred which is suitable for use on both the outer side of the housing part and the inner side of the housing part.

[0037] The above selection criteria also apply to an electrically insulating cast material.

[0038] Preferably, the at least one connection pad is attached to the base body in an electrically insulating manner over its entire surface using an adhesive or using a casting material as insulation material.

[0039] Alternatively, the connection pad can also be attached to the base body only partially, i.e., over parts of its surface, using an adhesive or a cast material as an insulating material. This can also achieve a sufficiently secure attachment. It is advantageous if adhesive or cast material is applied to the outer edges between the connection pad and the base body, so that no accessible gap remains between the aforementioned components.

[0040] The at least one first connection terminal arrangement, even with the provision of a connection pad, leads to a stiffening of the housing part, whereby the housing part is subject to only minimal deformation, particularly when subjected to pressure. Preferably, the insulation material and the connection pad(s) are designed and arranged such that the at least one first connection terminal arrangement, together with the base body, has a flexural strength in the region of the through-opening that is at least twice as high as the flexural strength of the base body without the first connection terminal arrangement.

[0041] Furthermore, the single-sided and especially double-sided arrangement of the connection pads protects the metal fixing material feedthrough of the connection pin. Especially with a double-sided design, the connection pin is mechanically protected from environmental influences such as impacts and the like. External mechanical influences are absorbed by the insulation material and the connection pad and transferred to the housing.

[0042] Preferably, the insulating material used to connect the connection pad(s) is arranged and configured such that the insulating material completely covers the fixing material. Covering the fixing material with the insulating material advantageously protects it not only from mechanical influences but also from moisture or the effects of other substances.

[0043] Preferably, the at least one connection pad is arranged and configured such that the connection pin does not protrude beyond the opening of the at least one connection pad. This ensures, particularly when the opening is designed as a through-hole, that the connection surface provided by the connection pad is not disrupted by protruding parts, and that even large connection lugs or electrical conductors, for example, can be easily connected to the connection pad.

[0044] Preferably, a shape of the opening of the at least one connection pad corresponds to a cross-sectional shape of the connection pin, wherein the size of the opening is preferably selected to be 0.02 mm to 0.1 mm larger than the corresponding size of the connection pin. This ensures that a gap between the at least one connection pad and the connection pin is as small as possible and a reliable electrical connection between the two can be easily established. At the same time, however, it is possible to compensate for manufacturing tolerances so that the connection pin can always engage in the opening of the connection pad reliably and without damaging or deforming the latter. By reshaping the connection pad and / or the connection pin after arrangement on the base body, the remaining gap can be further reduced or even completely closed. This also makes it possible to directly establish or at least improve the electrical connection.

[0045] Preferably, a connection between the terminal pin and the at least one terminal pad is implemented as a conductive adhesive connection or a welded connection. Soldering is also conceivable for electrically conductive connection. In the case of an opening configured as a through-hole, the connection preferably runs along the contour of the opening of the at least one terminal pad. In the case of an opening configured as a blind hole, the connection is preferably configured over the entire surface.

[0046] For example, laser welding, resistance welding, ultrasonic welding or friction welding can be used to form a welded joint.

[0047] The at least one connection pad advantageously provides a significantly larger connection area compared to the cross-sectional area of ​​the connection pin. The production of the metal fixing material feedthrough can advantageously be carried out separately from the arrangement and connection of the at least one connection pad, so that by adjusting the shape and size of the connection pad, the connection surfaces available for electrical contact can be easily adapted to the housing part as required, without the metal fixing material feedthrough having to be changed or adapted. The shape of an external connection pad can be selected independently of the shape of an internal connection pad, so that optimal shapes and arrangements for electrical contact can be selected in each case.

[0048] Preferably, the at least one connection pad has a shape selected from round shapes such as circles or ellipses, or from polygonal shapes such as rectangles, squares, triangles, or hexagons, each optionally with rounded corners. In principle, the shape of the at least one connection pad can be selected according to the requirements.

[0049] The dimensions of the connection pads of the first connection terminal arrangement, i.e., their width and length, are preferably selected such that a large surface is provided for welding or soldering connections such as connection lugs. Alternatively, connections can also be riveted or pressed for fastening. These dimensions can be significantly larger than the connection surfaces provided by conventional connection pins alone. This advantageously ensures that the shape and size of connection areas where electrical connections are made can be customized without the actual electrical feedthrough of the connection pin through the housing part having to be adapted or modified. In particular, angular shapes can also be easily created.

[0050] Adherence of the insulating material to smooth surfaces can be difficult. To improve the adhesion of the insulating material to the at least one connection pad and / or the base body, it is preferred to arrange structures on the respective surfaces of the connection pad and / or base body that border the insulating material, which roughen the respective surface and / or create undercuts into which the insulating material can grip.

[0051] Preferably, the base body has a microstructure at least in a connection region in which the base body is connected to the at least one connection pad, and / or the at least one connection pad on the side facing the base body. This microstructure improves the adhesion of the insulation material and thus increases the strength of the connection between the at least one connection pad and the base body.

[0052] The microstructuring can, in particular, involve a plurality of grooves and / or depressions, which can be constructed and produced in a similar way to the microstructures known from DE 10 2017 123 278 A1. The depth of the microstructures is preferably chosen to be somewhat greater to improve the adhesion of the insulation material than for the microstructures described therein for controlling the flow of a metallic solder material.

[0053] Preferably, the recesses of the microstructure are laser-structured areas in the surface of the base body and / or the connection pad. These laser-structured areas can advantageously be laser-ablated areas and / or areas locally thermally reshaped by laser radiation and / or locally reshaped by laser-induced pressure. Of course, any combination is possible.

[0054] Alternatively or additionally, other methods for producing the microstructuring can be used, such as embossing using microstructured stamps and / or material-removing methods such as grinding and / or scribing, etc.

[0055] Advantageously, the microstructure is in the form of grooves and / or the microstructure comprises or consists of depressions with round and / or oval diameters. Rectangular diameters, particularly with rounded corners, are also possible. Crater-shaped and / or pot-shaped depressions are particularly advantageous. These shapes can be produced particularly cost-effectively using laser ablation.

[0056] The depressions of the microstructures preferably have a depth of at least 1 µm, more preferably at least 10 µm, and most advantageously at least 100 µm. Up to a depth of 200 µm, the depressions are referred to as microstructures. This depth is measured from the plane of the surface of the base body outside the microstructure to the deepest point of the microstructure, e.g., in the case of crater-shaped depressions, from the plane of the surface of the base body outside the microstructure to the deepest point of the crater floor.

[0057] Preferably, the base body and / or the at least one connection pad has recesses or structures with at least one undercut into which the insulation material engages to connect the base body to the at least one connection pad.

[0058] For example, diagonal grooves can be incorporated into the surfaces of the base body and / or the connection pad. It is also conceivable to fold the edge of at least one connection pad inward in such a way that a circumferential groove is formed as an undercut.

[0059] The material for the at least one connection pad is preferably a metal with good electrical conductivity. The material of the at least one connection pad consists of or preferably comprises a material selected from aluminum, aluminum alloys, copper, and copper alloys, in particular brass and bronze. It is also conceivable to select so-called contact materials as the material for the at least one connection pad. The contact materials are characterized by good resistance to oxidation and are also resistant to wear caused by sparks and arcs. Suitable contact materials include, in particular, silver, gold, and platinum. Suitable alloys as contact materials include, in particular, silver-nickel and silver-tin oxide.

[0060] The first connection terminal arrangement can be easily obtained in various ways. First, the electrical feedthrough through the base body is formed. For this purpose, for example, a base body, a blank for the fixing material, and the connecting pin can be provided, and a metal fixing material feedthrough can be obtained in a heat treatment step. By appropriately dimensioning and positioning the connecting pin, it protrudes beyond the through-hole in the base body on one or both sides and can then be connected to one or more connecting pads on these sides.

[0061] In one variant, the connection pads are obtained by punching out a sheet metal material already coated with the insulating material, in particular an adhesive. The connection pad is then positioned over the protruding part of the connection pin and pressed against the base body.

[0062] Alternatively, it is of course possible to punch out the connection pads from uncoated sheet metal and to apply an adhesive to the connection pad and / or to the base body just before arranging it.

[0063] To use a cast material as insulation, the housing part and the connection pad can be placed in an injection mold. The insulation material is then injected into the mold.

[0064] The housing part preferably further comprises at least one second connection terminal arrangement, in which a connection area is formed by a raised portion in the base body or by a further connection pad that is electrically conductively connected to the base body. This makes it possible to provide a connection area on the housing part, in particular a connection area designed as a ground terminal or negative terminal, even without the presence of an electrical feedthrough through the base body.

[0065] In the alternative embodiment designed as a raised portion, advantageously no additional component is required to form the second connection terminal arrangement. This saves material and weight, in particular. The raised portion is preferably obtained by forming the base body, in particular by means of a through-hole.

[0066] The at least one second connection terminal arrangement makes it possible to provide a connection point, in particular for a ground connection, which, in preferred embodiments, requires no additional parts and yet provides the same overall height as the first connection terminal arrangement. An electrical connection to the second connection terminal arrangement can thus be configured in the same way as the electrical connection to the first connection terminal arrangement. Furthermore, the elevation and, if applicable, the corresponding recess on the opposite side create a wall that serves as a bead and provides mechanical reinforcement of the housing part without the need for additional material.

[0067] During the penetration process, the raised portion of the base body is shifted vertically relative to the remaining portion, with the wall thickness of the base body only changing in the transition area between these parts. This leaves the surface qualities, in particular, unchanged. However, other forming processes, such as deep drawing, can of course also be used.

[0068] If an additional connection pad is used to form the second connection terminal arrangement, it is preferably connected to the base body by welding, soldering, or bonding with an electrically conductive adhesive. The additional connection pad is preferably configured similarly or identically to one of the connection pads of the first connection terminal arrangement. Furthermore, it is conceivable to arrange an additional connection pad not only on an outer side, but also on the opposite inner side of the housing part.

[0069] Preferably, the overall height of the at least one first connection terminal arrangement and the at least one second connection terminal arrangement is selected to be identical. As a result, the areas intended for electrical contact are all at the same height with respect to the surface of the base body, so that all connections can be mechanically produced in the same way. In addition to the height, other geometric

[0070] Parameters, in particular the shape and size of the second connection terminal arrangement are adapted to the first connection terminal arrangement and are preferably selected to be identical.

[0071] Preferably, the total height of the connecting terminal arrangements, i.e., the at least one first connecting terminal arrangement and the optionally present at least one second connecting terminal arrangement, is selected, starting from a surface of the base body, in the range of 10% to 80% of the wall thickness of the base body. This allows, in particular, the second connecting terminal arrangement to be formed as a raised portion by means of a forming process.

[0072] The material of the base body is selected as required, preferably choosing a material that can be easily joined to the other housing parts. The material of the base body is preferably selected from a metal, in particular iron, iron alloys, iron-nickel alloys, iron-nickel-cobalt alloys, KOVAR, steel, stainless steel, aluminum, aluminum alloys, AlSiC, magnesium, magnesium alloys, titanium, or titanium alloys.

[0073] Due to their low weight, light metals such as aluminum, magnesium and titanium and their alloys are particularly preferred.

[0074] The material of the terminal pin is preferably selected from a metal with good electrical conductivity. Accordingly, the material of the terminal pin is preferably selected from copper, a copper alloy, aluminum, an aluminum alloy, iron, an iron alloy, an iron-nickel alloy, an iron-nickel-cobalt alloy, KOVAR, titanium, a titanium alloy, steel, stainless steel, stainless steel, AISI 304, magnesium, or a magnesium alloy.

[0075] The fixing material for holding and insulating the terminal pin in the through-hole of the base body is selected from a glass or a glass ceramic. The fixing material is preferably selected with respect to the material of the base body and the terminal pin so that a metal-fixing material feedthrough is formed.

[0076] To achieve a particularly good seal between the metal parts, i.e., the base body and the connecting pin of the at least one first connection terminal arrangement, and the fixing material, the feedthrough is designed in the form of a pressure glazing. The thermal expansion coefficient of the base body is selected to be greater than the thermal expansion coefficient of the fixing material, so that after a temperature treatment, during which the fixing material is glazed into the through-hole, the base body contracts more strongly than the fixing material. As a result, permanent compressive forces are exerted by the base body on the fixing material. These pre-tension the fixing material and ensure a particularly durable seal.

[0077] Accordingly, the thermal expansion coefficient of the base body is greater than the thermal expansion coefficient of the fixing material. Particularly preferably, in the case of pressure glazing, the thermal expansion coefficient of the base body is selected to be at least 5%, preferably at least 10%, particularly preferably at least 20%, and most preferably at least 50% greater than the thermal expansion coefficient of the fixing material.

[0078] As an alternative to a pressure glazing design, an adapted feedthrough could also be used, in which the thermal expansion coefficients of the base body, the fixing material and the connecting pin are adapted to one another, which is not part of the invention. Adapted here is understood to mean that the expansion coefficients differ essentially by a maximum of 2 * 10 -6 < 1 / K, in particular by a maximum of 1 * 10 -6 < 1 / K, in particular are essentially the same, and / or are preferably in the range 3 to 7 * 10 -6 < 1 / K, preferably 4.5 to 5.5 * 10 -6 < 1 / K or in the range from 9 * 10 -6 < 1 / K to 11 * 10 -6 < 1 / K. Overall, the expansion coefficients can therefore be in the range 3 to 11 * 10 -6 < 1 / K. Where reference is made to the thermal expansion coefficient in the present application, this is understood to mean the linear thermal expansion coefficient α in the range of 20-300°C.

[0079] In order to simplify joining the housing part with other housing components, the housing part preferably has a circumferential connecting flange.

[0080] The housing part preferably further comprises at least one functional element selected from a safety valve or a filling opening. Such a safety valve can be provided, for example, as a predetermined breaking point or a weakened section of the housing part, wherein the predetermined breaking point or the weakened section are designed and arranged such that they fail at a predetermined pressure and allow excess pressure to escape from the interior of a housing formed with the housing part.

[0081] The housing part is preferably designed as a cover of a housing. By joining the cover to a housing body, a housing for an electrical storage device can be formed. This can comprise one or more electrical storage cells, for example, battery cells or capacitor cells.

[0082] Accordingly, it is a further object of the invention to provide an electrical storage device, in particular a battery or a capacitor, which comprises one of the housings or housing parts described herein and at least one storage cell.

[0083] The invention will be described in more detail below with reference to the figures and without limitation thereto.

[0084] They show: Fig. 1 : a view of the underside of a housing part designed as a cover, Fig. 2 : a sectional view of the housing part along the Figure 1 marked cutting line, Fig. 3 : an enlarged view of a first connection terminal arrangement of the cover part, Fig. 4 a second example of a first connection terminal arrangement, Fig. 5 a third example of a first connection terminal arrangement, Fig. 6 a fourth example of a first connection terminal arrangement, Fig. 7 a fifth example of a first connection terminal arrangement, Fig. 8 a first variant of Fig. 4 , Fig. 9 a second variant of Fig. 4 and Fig. 10 a third variant of Fig. 4 .

[0085] In Figure 1 An embodiment of a housing part 10 designed as a cover is shown in a view from below. InIn this exemplary embodiment, the housing part 10 has a base body 12 with a first connection terminal arrangement 100 and a second connection terminal arrangement 200. If the housing part 10 is connected to one or more electrical storage cells, for example, a battery cell or a capacitor cell, the first connection terminal arrangement 100 can serve, for example, as a positive terminal and the second connection terminal arrangement 200 can serve, for example, as a negative terminal.

[0086] The housing part 10 can have further functional elements in addition to the connection terminal arrangements 100, 200. In the in Figure 1In the example shown, a safety device in the form of a safety valve 18 and a filling opening 16 are provided for this purpose. The safety valve 18 can, for example, be designed as a predetermined breaking point in the housing part 10, wherein the safety valve is configured to open at a defined pressure. After all parts of the housing have been assembled, the interior can be filled with a liquid or gaseous medium, for example, an electrolyte, through the filling opening 16. After filling, the filling opening 16 is usually closed.

[0087] For connection with other housing parts, the Figure 1 In the example shown, a circumferential connecting flange 14 is provided. This can be designed, for example, as a welding flange.

[0088] Figure 2 shows the housing part of the Figure 1 in a sectional view from the side along the Figure 1cutting line marked AA. In In this sectional view, the structure of the first connection terminal arrangement 100 and the second connection terminal arrangement 200 can be clearly seen.

[0089] The first connection terminal arrangement 100, which in Figure 3 is shown enlarged, comprises a connection pin 102, which is inserted into a through-opening 20 of the base body 12 and is held by a fixing material 106. The fixing material 106 also electrically insulates the connection pin 102 from the base body 12. In the example shown, the connection pin 102 protrudes beyond the base body 102 or the through-opening 20 on both a top side and a bottom side.

[0090] A connection pad 110 is arranged on the upper side of the base body 12 and is fastened to the base body 12 with an insulating material 112, for example an adhesive. The connection pad 110 has an opening 120 into which the connection pin 102 engages. For this purpose, the opening 120 has essentially the same shape as the cross-section of the connection pin 102, wherein the opening 120 is preferably somewhat larger so that the connection pin 102 can engage in this opening 120 even in the event of any manufacturing tolerances. The connection pin 102 touches the connection pad 110 or there is only a small gap between them, so that an electrical connection can be established between the two by a welded connection 130. Such a welded connection 130 is preferably formed along a contour of the opening 120.The connection pad 110 is located on the outside after the housing has been assembled so that it can serve as a connection area for electrical contact.

[0091] In the Figures 2 and 3In the example shown, an inner connection pad 116 is arranged on the underside of the base body 12, which is fastened to the underside of the base body 12 via an inner insulation material 114. The inner connection pad 116 also has an opening 120 into which the connection pin 102 engages. The connection pin 102 is also electrically connected to the inner connection pad 116 along the contour of the opening 120, for example by a welded connection 130. After the housing has been assembled, the inner connection pad 116 is located inside the housing, so that it can serve as a connection area for memory cells accommodated inside the housing. For example, connection lugs of memory cells can be connected to the connection pad, in particular they can be welded.

[0092] The dimensions of the insulation material 112, 114 are shown in Figures 1 to 3In the example shown, the insulation material 112, 114 is adapted to the dimensions of the connection pads 110, 116, so that the insulation material 112, 114 is completely covered. Alternatively, for example, to increase a creepage distance, it is possible to increase the dimensions of the insulation material 112, 114, so that a part of the insulation material 112, 114 protrudes beyond the connection pads 110, 116, which is shown as an example in the Figures 8 and 9 is shown schematically.

[0093] In the Figure 2The second connection terminal arrangement 200 is also shown. This has an elevation 202 on an outer side of the housing part 10, through which a connection region 210 is provided. On the opposite inner side, the second connection terminal arrangement 200 has a corresponding recess 204. The wall 206 of the recess formed in this way contributes to stiffening the housing part 10 like a bead. The elevation 202 is preferably designed such that the height of the second connection terminal arrangement 200 corresponds to the overall height of the first connection terminal arrangement 100, i.e., the thickness of the insulation material 112 and the thickness of the connection pad 110. Furthermore, the dimensions, i.e., the length and width, of the connection region 210 are preferably selected such that they correspond to the dimensions of the connection pad 110.Advantageously, the first connection terminal arrangement 100 and the second connection terminal arrangement 200 then have the same height relative to the base body 12 and the same dimensions, so that electrical contact is facilitated.

[0094] The second connection terminal arrangement 200 is preferably obtained by forming the material of the base body 12. The forming preferably takes place by means of a punching process, in which the region of the elevation 202 is displaced vertically. In this process, the material thickness of the base body 12 changes only in a transition region, so that in the region of the elevation 202, the material thickness is equal to the material thickness of the base body 12 outside the second connection terminal arrangement 200.

[0095] Figure 4 shows a second embodiment of the first connection terminal arrangement 100. As with reference to the Figures 1 to 3As already described, the first connection terminal arrangement 100 comprises an electrical feedthrough in which the connection pin 102 is held in the through-opening 20 of the base body 12 by the fixing material 106. The fixing material 106 also seals the connection pin 102 and the wall of the through-opening 20, so that the feedthrough is sealed. The feedthrough is preferably hermetically sealed.

[0096] In contrast to the Figures 1 to 3In the first exemplary embodiment shown, the connection pad 110 has an opening 120 designed as a blind hole, into which a part of the connection pin 102 protruding beyond the through-opening 20 engages. For the electrical connection between the connection pin 102 and the connection pad 110, a conductive adhesive 140 is introduced in the region of the blind hole. In the remaining areas between the connection pad 102 and the base body 102, an electrically insulating adhesive is used as the insulating material 112 to fix the connection pad 102 to the base body 12.

[0097] As shown in the illustration of the Figure 4As can be seen, there is no seam in the area of ​​the connecting pin 102 and a surface of the connecting pad 110, thus providing a continuous, flat connecting surface. The connecting pin 102 and the fixing material 106 are completely covered by the connecting pad 110, with the connecting pad 110 having a thinned area 140 with a reduced wall thickness in the area of ​​the opening 120 formed as a blind hole.

[0098] Figures 5 , 6 and 7 show three further embodiments of the first connection terminal arrangement 100. The base body 12 and the electrical feedthrough formed by the connection pin 102 and the fixing material 106 are designed as described with reference to the previous embodiments. The part of the connection pin 12 protruding beyond the through-opening 20 in the base body 12 is designed as with reference to the first embodiment of the Figures 1 to 3electrically connected to the connection pad 110 by a welded connection 130.

[0099] In the first connection terminal arrangement 100 of the Figures 5 , 6 and 7 However, in contrast to the above, a cast material, such as a thermoplastic or thermosetting plastic, is used as the insulating material 112 to connect the connection pad 110 and the base body 12. To ensure that the insulating material 112 can bond well to the base body 12 and the connection pad 110, undercuts 119 are provided.

[0100] In the in Figure 5 In the third exemplary embodiment shown, a recess 118 is arranged in the base body 12, which recess 118 extends around the opening 20 and has an undercut 119 in the form of a circumferential protruding elevation within the recess 118. A collar 117 is formed on the connection pad 110 by folding over the edge, which represents a circumferential undercut 119.

[0101] In the Figure 6 In the fourth exemplary embodiment shown, a recess 118 is again arranged in the base body 12, which recess 118 extends around the opening 20 and has an undercut 119 in the form of a circumferential protruding elevation within the recess 118. Several recesses in the form of oblique grooves are arranged on the connection pad 110, which, due to their design, also form an undercut 119.

[0102] In the Figure 7 In the fifth embodiment shown, recesses 118 in the form of oblique grooves are formed on both the base body 12 and the connection pad 110, each of which provides an undercut 119 as a support for the insulation material 112.

[0103] Instead of or in addition to the provisions in the Figures 5 to 7The surfaces of the connection pad 110 and the base body 12 facing the insulating material 112 can be provided with a microstructure, similar to the grooves and depressions shown. This creates numerous depressions and / or grooves that provide support for the insulating material 112.

[0104] The Figures 8 to 10 show measures for increasing the creepage distance at the edge of a connection pad 110. These are shown here as an example for the second example of a first connection terminal arrangement 100 (cf. Figure 4 ). Of course, they are not limited to connection pad embodiments with an opening 120 designed as a blind hole, but can also be used with other examples of a first connection terminal arrangement, in particular with embodiments according to the Figures 1 to 3 , be combined.

[0105] In the Figure 8In the first variant shown for extending the creepage distance, the outer dimension of the insulating material 112 is selected to be larger than the outer dimension of the connection pad 110, so that a part of the insulating material 112 protrudes beyond the connection pad 110.

[0106] Alternatively or in addition to a projecting part of the insulating material 112, a further insulating element 150 can be provided in the edge region of the connection pad 110, which surrounds the connection pad 110 laterally. Figure 9 In the second variant shown for extending the creepage distance, the further insulating element 150 is attached, for example glued, to the side next to the connection pad 110 on the protruding insulating material 112.

[0107] Figure 10shows a third variant for extending the creepage distance in an embodiment in which the insulating material 112 is completely covered by the connection pad 110. To extend the creepage distance, an insulating creepage extension 151 is provided, which covers the gap 152 between the base body 12 and the connection pad 110. To provide the creepage extension 151, for example, after the connection pad 110 has been attached to the base body 12, an "adhesive bead" made of insulating material can be placed around the connection pad 110 in an additional work step. Alternatively, the insulating material can be made thicker at least partially under the connection pad 110 and / or in the edge region below the connection pad 110, for example,an adhesive bead may be provided so that when the connection pad 110 is attached to the base body 12, material is pressed out at the edges and thereby forms the creepage distance extension at the joint 152.

[0108] The claims are not limited to the embodiments described herein. In particular, numerous modifications are possible in which individual features of the embodiments described herein are combined with one another. List of reference symbols

[0109] 10Housing part 12Base body 14Connecting flange 16Filling opening 18Safety device 20Through opening ASection line 100First connection terminal arrangement 102Connection pin 104Through hole 106Fixing material 110Connection pad 112Insulation material 114Inner insulation material 116Inner connection pad 117Collar 118Recess 119Undercut 120Opening 122Thin area 130Welded joint 140Conductive adhesive 150Further insulation element 151Creepage distance extension 152Gap 200Second connection terminal arrangement 202Elevation 204Enforcement 206Wall enforcement 210Connection area

Claims

1. Housing part (10) for an electrical storage installation, in particular a battery or a capacitor, comprising a main body (12) and at least one first connector terminal assembly (100) having a connector pin (102) which is routed through a through opening (20) of the main body (12) and by way of a fixing material (106) is fixed so as to be electrically isolated in the through opening (20), wherein the connector pin (102) on at least one side of the through opening (20) projects beyond the latter, characterized in that provided on at least one side of the through opening (20) is a terminal pad (110, 116) which has an opening (120) that is configured as a through opening or as a blind bore, wherein the projecting part of the connector pin (102) engages in the opening (120) and in the region of this opening (120) is electrically connected to the at least one terminal pad (110, 116), and wherein the at least one terminal pad (110, 116) by way of an insulation material (112, 114) is fastened so as to be electrically isolated on the main body (12), wherein the insulation material (112, 114) is an electrically isolating adhesive, or an electrically isolating potting material, wherein the fixing material (106) is selected from glass, or glass ceramics, and the connection between the fixing material (106) and the connector pin (102) and between the fixing material (106) and the wall of the through opening (20), is hermetically tight, wherein a first thermal expansion coefficient of the main body (12) is greater than a second thermal expansion coefficient of the fixing material (106).

2. Housing part (10) according to Claim 1, characterized in that the connector pin (102) on both sides of the through opening (20) projects beyond the latter, and disposed on both sides of the through opening (20) are terminal pads (110, 116) which have in each case an opening (120), wherein the projecting part of the connector pin (102) engages in each case in the respective opening (120) and in the region of this opening (120) is electrically connected to the respective terminal pad (110, 116).

3. Housing part (10) according to Claim 1 or 2, characterized in that the at least one terminal pad (110, 116), while using the adhesive or while using the potting material as an insulation material (112, 114), is fastened across the entire area so as to be electrically isolated on the main body (12), and / or in that the insulation material (112, 114) completely covers the fixing material (106).

4. Housing part (10) according to one of Claims 1 to 3, characterized in that the at least one terminal pad (110, 116) is disposed and specified in such a manner that the connector pin (102) does not protrude beyond the opening (120) of the at least one terminal pad (110, 116).

5. Housing part (10) according to one of Claims 1 to 4, characterized in that a shape of the opening (120) of the at least one terminal pad (110, 116) corresponds to a cross-sectional shape of the connector pin (102), wherein the size of the opening (120) is preferably chosen so as to be larger by 0.02 mm to 0.1 mm than the corresponding size of the connector pin (102).

6. Housing part (10) according to one of Claims 1 to 5, characterized in that a conductive adhesive connection, a welded connection or a soldered / brazed connection is used for connecting the connector pin (102) and the at least one terminal pad (110, 116), said conductive adhesive connection, welded connection or soldered / brazed connection in the case of an opening (120) configured as a through opening preferably being established along the contour of the opening (120) of the at least one terminal pad (110, 116), or in the case of an opening (120) configured as a blind bore preferably being established across the entire area.

7. Housing part (10) according to one of Claims 1 to 6, characterized in that the at least one terminal pad (110, 116) has a shape that is selected from round shapes such as circles or ellipses, or selected from polygonal shapes such as rectangles, squares, triangles or hexagons, in each case optionally having radiused corners.

8. Housing part (10) according to one of Claims 1 to 7, characterized in that the main body (12), at least in a connection region in which main body (12) is connected to the at least one terminal pad (110, 116), and / or the at least one terminal pad (110, 116) on the side facing the main body (12), has a microstructure.

9. Housing part (10) according to one of Claims 1 to 8, characterized in that the main body (12) and / or the at least one terminal pad (110, 116) have / has depressions (118) or structures with at least one undercut (119) into which the insulation material (112, 114) engages in order to connect the main body (12) to the at least one terminal pad (110, 116).

10. Housing part (10) according to one of Claims 1 to 9, characterized in that the terminal pads (110, 116) are composed of a material selected from aluminium, aluminium alloys, copper, copper alloys, in particular brass and bronze, silver, gold, platinum and silver alloys, in particular silver-nickel and silver-tin oxide.

11. Housing part (10) according to one of Claims 1 to 10, characterized in that the housing part (10) furthermore comprises at least one second connector terminal assembly (200) in which a connector region (210) is formed by an elevation (202) in the main body (12), or is formed by a further terminal pad which is connected in an electrically conductive manner to the main body (12), wherein the elevation (202) has preferably been obtained by forming the main body (12), in particular by shear forming.

12. Housing part (10) according to one of Claims 1 to 11, characterized in that an overall height of the at least one first connector terminal assembly (100) and of the at least one second connector terminal assembly (200) are chosen so as to be identical, wherein the overall height of the connector terminal assemblies (100, 200), proceeding from a surface of the main body (12), is chosen so as to be in the range from 10% to 80% of the wall thickness of the main body (12).

13. Housing part (10) according to one of the preceding claims, characterized in that the material of the main body (12) is selected from a metal, in particular iron, iron alloys, iron-nickel alloys, iron-nickel-cobalt alloys, KOVAR, steel, stainless steel, aluminium, aluminium alloys, AlSiC, magnesium, magnesium alloys, titanium or titanium alloys, and / or in that the material of the connector pin (102) is selected from copper, a copper alloy, aluminium, an aluminium alloy, iron, an iron alloy, an iron-nickel alloy, an iron-nickel-cobalt alloy, KOVAR, titanium, a titanium alloy, steel, high-grade steel, stainless steel, AlSiC, magnesium, a magnesium alloy.

14. Housing part (10) according to one of the preceding claims, characterized in that the first thermal expansion coefficient of the main body (12) is at least 5% greater than the second thermal expansion coefficient of the fixing material (106).

15. Housing part (10) according to one of the preceding claims, characterized in that the housing part (10) is configured as a lid of a housing, and preferably has an encircling connection flange (14) for connecting to a further housing part.

16. Housing part (10) according to one of the preceding claims, characterized in that the at least one first connector terminal assembly (100), conjointly with the main body (12), in the region of the through opening (20) has a flexural strength which is at least double the flexural strength of the main body (12) without the first connector terminal assembly (100).

17. Electrical storage device, in particular a battery or a capacitor, comprising a housing and at least one storage cell, characterized in that the housing comprises a housing part (10) according to one of Claims 1 to 16.