Electrical feedthrough and energy storage with such feedthrough

Abstract

An electrical bushing (10), in particular for an electrical storage device, is provided. The electrical bushing (10) comprises a base body (12) with a through-opening (14) and a connecting pin (20) arranged in the through-opening (14), which is held in the through-opening (14) by means of a fixing material (16) in an electrically insulating manner.Furthermore, it is provided that the connecting pin (20) has a core (22) made of copper or a copper alloy or CuSiC as the first electrically conductive material and has at least on a first side of the electrical feedthrough (10) a cover material (24) made of aluminum or an aluminum alloy or AlSiC as the second electrically conductive material, which covers a first end face (23a) of the core (22), wherein the connecting pin (20) and the fixing material (16) are designed and arranged such that a transition (26a) from the core (22) to the cover material (24) lies outside the fixing material (16).

Description

[0001] The invention relates to an electrical feedthrough, in particular for an electrical storage device, comprising a base body with a through-opening and a connecting pin arranged in the through-opening, which is held in the through-opening in an electrically insulating manner by a fixing material. A further aspect of the invention relates to a connecting pin for an electrical feedthrough. A further aspect relates to an electrical energy storage device comprising at least one such feedthrough.

[0002] Electrical energy storage devices such as batteries or capacitors, the latter including supercapacitors, are used in a wide variety of applications for storing and providing electrical energy. Electrical energy storage devices typically comprise a housing and at least one storage cell housed within the housing. The storage cell can be electrically contacted from the outside via at least one electrical feedthrough in the housing.

[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] 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.

[0005] 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.

[0006] EP 2 371 419 A2 shows an electrical feedthrough of a capacitor for medical implants, as well as methods for producing and using such a capacitor. It is disclosed that the connecting pin can consist of two pin sections: a first pin section made of Pt, Pt / Ir, FeNi, FeNiCo, FeCr, Nb, Ta, Mo, W, Cr, FeCr, V, or Ti, and a second pin section comprising aluminum, wherein the joint between the pin sections is arranged within a glass plug or a filler plug.

[0007] US 2014 / 212741 A1 discloses a conductor for an electrochemical battery comprising two sections: a first section made of a light metal facing the outside, and a second section made of copper facing the inside. The transition between the two sections is sealed by a mechanical seal.

[0008] WO 2016 / 074932 discloses a housing or housing part with a feedthrough comprising a pin-shaped conductor with a first section made of light metal and a second section made of copper or a copper alloy. The pin-shaped conductor is held in an insulating manner in a through-hole in the housing or housing part by a glass or glass-ceramic material, with the transition between the different sections of the pin-shaped conductor being located in the region of the glass or glass-ceramic material.

[0009] WO2021 / 185648 A1 discloses a microbattery characterized by a particularly compact design. A metal fixing material feedthrough for an electrical connection of the microbattery can be designed as a pressure-sealed glazing, thus ensuring a particularly reliable seal for the feedthrough.

[0010] A disadvantage of the known metal-fixing material feedthroughs with pressure-inserted glazing or adapted feedthroughs is that they cannot currently be reliably manufactured with a connecting pin made of any desired material. Connecting pins made of a material adapted to the materials of a battery or capacitor would be desirable, for example, to prevent corrosion and / or improve contactability. Accordingly, it is an object of the invention to provide an electrical feedthrough in which the connecting pin can be adapted to both the requirements of the battery and the requirements of the metal-fixing material feedthrough. Disclosure of the invention

[0011] An electrical feedthrough is proposed, in particular for an electrical storage device. The electrical feedthrough comprises a base body with a through-opening and a connecting pin arranged in the through-opening, which connecting pin is held in the through-opening in an electrically insulating manner by means of a fixing material. Furthermore, it is provided that the connecting pin has a core selected from copper, a copper alloy, or CuSiC as the first electrically conductive material and, at least on a first side of the electrical feedthrough, has a covering material selected from aluminum, an aluminum alloy, or AlSiC as the second electrically conductive material, which covers a first end face of the core, wherein the connecting pin and the fixing material are designed and arranged such that a transition from the core to the covering material lies outside the fixing material.

[0012] The transition is a material boundary within the terminal pin, formed or located at an end face of the core. Because the transition between the core material, i.e., a central portion of the terminal pin, and the cover material, which is arranged on an end face of the core, is located outside the fixing material, a particularly stable feedthrough is achieved, since different thermal expansion behaviors of the two electrically conductive materials do not affect the contact area between the terminal pin and the fixing material, which could otherwise lead to a weakening of the feedthrough.In addition, this increases the material selection for the base body and / or the fixing material for providing a hermetically sealed feedthrough, since the design of the metal-fixing material feedthrough does not have to take into account the different thermal expansion behavior of two electrically conductive materials in the contact area with the fixing material.

[0013] In the context of the invention, "core" is understood to mean a section of the terminal pin which, relative to a longitudinal axis of the terminal pin, preferably makes up at least 50% of the length. Advantageously, the core forms the main part of the terminal pin and makes up more than 50%, advantageously at least 55% or at least 60% of the length of the terminal pin. The longitudinal axis of the terminal pin extends in a direction parallel to the axis of the through-opening. In the case of a substantially flat base body, the longitudinal axis of the terminal pin extends correspondingly perpendicular to a plane of the base body in which the through-opening is formed.

[0014] Within the scope of the invention, in an electrical feedthrough or in a connecting pin for an electrical feedthrough, the length of the connecting pin can advantageously be 2 mm to 8 mm, preferably 3 mm to 6 mm. The diameter of the connecting pin can be 1 mm to 20 mm, preferably 2 mm to 10 mm.

[0015] The length or thickness of the core is advantageously 50% to 95%, preferably 60% to 90%, particularly preferably 70% to 80% of the length of the terminal pin. The length or thickness of the core can advantageously be at least or more than 50%, preferably at least 55%, preferably at least 60%, preferably at least 70%, in some advantageous variants at least 80% or at least 90%. An advantageous upper limit for the length or thickness of the core can be a maximum of 95% of the length of the terminal pin. In some advantageous variants, the length or thickness of the core can be a maximum of 90%, particularly preferably a maximum of 80% or a maximum of 75%.

[0016] The thickness or length of the covering material is advantageously 50% to 5%, preferably 40% to 10%, particularly preferably 30% to 20% of the length of the terminal pin. The thickness or length of the covering material can advantageously be at most or less than 50%, preferably at most 45%, preferably at most 40%, preferably at most 30%, in some advantageous variants at most 25% or at most 20% or at most 15%. An advantageous lower limit for the thickness or length of the covering material can be at least 5% or at least 10%, preferably at least 20%, in some advantageous variants at least 25%.

[0017] To minimize the overall height of the feedthrough, maximize the volume inside the housing, and ensure a reliably sealed feedthrough, the fixing material advantageously borders the core of the terminal pin. Preferably, the fixing material borders directly on the core, meaning the fixing material and the core or the outer surface of the core are in direct contact with each other.

[0018] In an advantageous variant, the minimum thickness of the terminal pin core is determined by the height of the fixing material. The thickness of the cover material depends on the terminal's current-carrying capacity and the desired method for connecting additional terminals to the cover layer. A suitable connection method may be laser welding.

[0019] The base body, the fixing material, and the connecting pin form a metal-fixing material feedthrough, which closes the through-hole of the base body. The resulting feedthrough is preferably hermetically sealed. Hermetically sealed means a He leakage rate of 1 10 -8 mbar I / s at 1 bar pressure difference.

[0020] The base body can, in particular, be a housing part for forming a housing for an electrical storage device. For example, the base body can be designed as a cover part which can be joined together with a cup-shaped housing part to form a housing for an electrical storage device. However, the base body can also be a component of a cover or cover part by being inserted into an opening formed in a cover element. The electrical storage device can, in particular, be a battery or a capacitor, including a supercapacitor, wherein one or more storage cells are usually accommodated in the housing and can be electrically contacted from the outside via the electrical feedthrough as a connection terminal.The feedthrough can also be designed as a multi-pole feedthrough in which the base body has several through-openings and in each of the through-openings a connecting pin is held by a fixing material.

[0021] It is advantageous if the first side of the electrical feedthrough, on which the covering material is located, is the side that faces outward when a housing is formed. The first end face of the terminal pin with the covering material thus faces outward when a housing is formed. An alternative arrangement, in which the covering material is arranged on the second side, which faces inward when a housing is formed, is of course also possible and equally advantageous.

[0022] The proposed terminal pin comprises at least two different electrically conductive materials, wherein the first electrically conductive material of the core, which is preferably selected from copper or a copper alloy, is selected according to the requirements of the metal-fixing material feedthrough. The material is selected in particular with regard to the thermal expansion coefficient and resistance to deformation in interaction with the material properties of the base body and the fixing material. In particular, copper or a copper alloy also exhibits high chemical resistance to materials of the storage cell, especially battery electrolytes, and is therefore corrosion-resistant.The second electrically conductive material of the cover material, which is preferably selected from aluminum or an aluminum alloy, can perform various functions depending on its arrangement on the outward-facing or inward-facing side when forming a housing. When arranged on the outward-facing side, it optimizes the terminal pin with regard to simple and secure connection to electrical terminals due to its good welding or soldering properties. When arranged on the inward-facing side, it can further optimize the terminal pin with regard to chemical resistance to storage cell materials and electrochemical potentials and / or improve contactability there as well.

[0023] In an advantageous embodiment, the connecting pin has a cylindrical shape. It can advantageously have a cylindrical body or be present as a cylindrical body, so that the connecting pin has a lateral surface and two end faces. The lateral surface of the cylinder is directed towards the fixing material, and the covering material, which covers a first end face of the core, is provided on at least one of the end faces of the connecting pin. The core is preferably also cylindrical and has a lateral surface. If the connecting pin is designed such that no further layer is present on the second end face of the core, which is opposite the first end face, the end face of the core simultaneously forms the end face of the connecting pin.

[0024] The connecting pin advantageously has a circular cylindrical shape. In addition to the circular cylindrical shape, general cylindrical shapes with other end face shapes are also conceivable. For example, oval shapes or rectangles with rounded corners are conceivable. Furthermore, the connecting pin can have a so-called nailhead shape, which can be formed, for example, by two adjacent cylinders. A first end face of such a nailhead-shaped connecting pin is formed by a cylindrical end face with the larger surface area, and a second end face is formed by a cylindrical end face with the smaller surface area.

[0025] In addition to covering a first end face of the core with the covering material, it may be advantageous in some variants to also cover a second end face of the core opposite the first end face with a further covering material made of a third electrically conductive material. The third electrically conductive material can be selected to be identical to or different from the second electrically conductive material. With a different selection, the second electrically conductive material in particular can be optimized for simple and secure connection to electrical terminals, and the third electrically conductive material can be adapted, for example, to the requirements of the materials of a memory cell. Welding properties or soldering properties, for example, can be used as a criterion for material selection.

[0026] In an advantageous variant of the invention, a lateral surface of the core facing the fixing material is at least partially not covered with covering material and directly borders the fixing material. Preferably, the lateral surface of the core is completely free of the covering material. The covering material thus forms a layer or ply on an end face of the core. In another variant of the invention, the surface of the core is completely covered with covering material, so that, in particular, the lateral surface is also completely covered with covering material.

[0027] Preferably, the melting point of the fixing material is selected to be lower than the melting point of all materials of the connecting pin. This ensures that the connecting pin is not damaged during the production of the metal fixing material through a heat treatment step, e.g., for sintering or vitrifying the fixing material. In an advantageous variant, however, it may be sufficient if the melting point of the fixing material is selected to be lower than the melting point of the core material, i.e., it is only matched to the core material.

[0028] During a heat treatment step, the fixing material can be obtained from a compact comprising, for example, a glass powder, a glass-ceramic powder, or a ceramic powder. The glass powder can consist of or comprise a partially crystallizable glass, so that during a heat treatment, the partially crystallizable glass is ceramized, resulting in a glass-ceramic.

[0029] Preferably, the second electrically conductive material and / or the third electrically conductive material is applied to the end face of the core by means of plating, electroplating, coating, vapor deposition, welding, or soldering. If only comparatively thin thicknesses of the covering material are applied, electroplating, coating, and vapor deposition can be advantageous. Possible vapor deposition processes include, for example, physical vapor deposition (PVD) methods such as sputtering, chemical vapor deposition (CVD), or plasma-enhanced chemical vapor deposition (PECVD). Conversely, plating, welding, and soldering are preferred if comparatively thick thicknesses of the covering material are applied.During soldering or welding, the covering material, for example, in the form of a sheet or foil—in the case of the second electrically conductive material, a sheet or foil, particularly made of aluminum or aluminum alloy—can be applied to the core material, particularly made of copper or copper alloy, and welded or soldered to it. Regardless of the application method, the covering material is preferably arranged free of openings or defects, so that the corresponding end face of the core is completely covered.

[0030] Furthermore, the covering material is preferably selected and arranged such that it is suitable for soldering or welding electrical contacts, such as contact tabs. Accordingly, the covering material is preferably designed such that it is suitable for soldering or welding electrical contacts, while preventing any cracks or openings from forming in the covering material.

[0031] An advantageous further development provides that the connecting pin consists of a layered composite material or comprises a layered composite material which has a layer of the first electrically conductive material, preferably of copper or a copper alloy, and at least one layer of the second electrically conductive material, preferably of aluminum or an aluminum alloy, wherein the previously individual layers are connected to one another, resulting in the layered composite material.

[0032] The layered composite material is preferably a clad layered composite material, also referred to as a "composite material" for short. An advantageous terminal pin made of such a material is a clad terminal pin. In an advantageous variant, the terminal pin is thus a clad terminal pin made of a clad layered composite material or comprising such a layered composite material, which has a layer of copper or a copper alloy and at least one layer of aluminum or an aluminum alloy.

[0033] Preferably, it is a roll-clad composite material, alternatively, an explosion-clad composite material. During cladding, the starting materials—in this case, the cover material and the core material, as well as any additional cover material—are typically prepared in the form of plates or strips, superimposed, and bonded together, for example, by rolling.

[0034] A micrograph of the connecting pin in the area of ​​the transition or connection zone between the core and cover material shows which process was used to produce a layered composite. A plated, in particular roll-clad, connecting pin is characterized by essentially uniformly smooth surfaces in the connection zone, whereas a friction-welded connecting pin, for example, has an irregular surface in the connection zone, such as a wavy structure. Furthermore, in a friction-welded connecting pin, circular connection structures can be seen in a micrograph of the connection zone (parallel to the connection zone). These are due to the relative movement of the connecting pin parts to be connected under pressure. An advantageous plated connecting pin does not have such connection structures.A plated terminal pin can be distinguished from a terminal pin with a soldered, in particular brazed, covering material layer by the fact that no solder material is present in the connection zone.

[0035] If the terminal pin is to have an additional covering material made of a third electrically conductive material, in an advantageous embodiment, the additional covering material can also be integrated into the layered composite material by plating, in particular by providing it in the form of a plate or strip, superimposed, and bonded to the other layers, for example, by rolling. Alternatively, however, the additional covering material can also be applied to the end face of the core by another method. Alternative methods have been described above.

[0036] The plated terminal pin is advantageously separated from the plated composite material by means of a separation process, in particular by cutting. It is preferably a cut-out, plated terminal pin that is separated from the composite material by a cutting process, preferably selected from laser cutting, waterjet cutting, or shear cutting. This allows the terminal pin to be manufactured more economically and in larger quantities than by individual part production as in the other mentioned methods for producing a terminal pin from a core and at least one covering material, for example, a terminal pin manufactured by friction welding.

[0037] Using cutting processes such as laser cutting and waterjet cutting, the latter of which may involve the addition of abrasive media to the water, terminal pins can be manufactured in small to medium quantities. The terminal pin is preferably cut out by shear cutting, particularly preferably by punching, which allows terminal pins to be produced cost-effectively in large quantities. In particular, shear cutting, preferably punching, allows the outer shape of the terminal pin, in particular a cylindrical terminal pin, to be created in a single operation.

[0038] In an advantageous variant, the connecting pin is a punched connecting pin. Since cut or punched workpieces exhibit characteristic shape defects—for example, (in the case of shear cutting) edge indentation due to plastic deformation, fracture zones, cutting burrs, etc.—the shape characteristics of the connecting pin can be used to determine how it was manufactured. A laser-cut connecting pin, for example, exhibits a thermally influenced edge zone, in particular a melted edge layer. A waterjet-cut connecting pin exhibits a mechanically altered edge zone. Shape defects and edge zone changes can be detected, for example, by microscopic examination of the cut edge.

[0039] In a particularly advantageous variant, the connecting pin is a stamped, plated, in particular roll-plated, connecting pin.

[0040] Further details of the terminal pin are described below in connection with a further aspect of the invention, to which reference is made here to avoid repetition.

[0041] Preferably, one end face of the terminal pin is arranged flush with a surface of the base body. If the base body has regions of different thicknesses, it is preferred that one end face be flush with the surface of the base body adjacent to the through-hole. Particularly when combined with a fixing material that is flush with the surface of the base body, this achieves a flat shape for the electrical feedthrough, and the feedthrough advantageously has the smallest possible height.

[0042] Alternatively, it is preferred that one or both end faces of the terminal pin protrude beyond a surface of the base body. If the base body has regions of different thicknesses, it is preferred that one or both end faces protrude beyond the surface of the base body adjacent to the through-opening. This creates a raised contact surface, which allows for easy electrical contacting of the terminal pin, for example, by welding contact lugs.

[0043] The material of the base body is preferably selected from light metal, light metal alloy, AlSiC, steel, in particular ferritic, austenitic, or duplex steel, stainless steel, stainless steel, or tool steel. The light metal or light metal alloy can advantageously be aluminum, aluminum alloy, titanium, titanium alloy, magnesium, or magnesium alloy. The material of the base body is preferably selected from aluminum or aluminum alloy or AlSiC. AlSiC has a SiC matrix infiltrated with Al.

[0044] In the context of the disclosure, light metals are understood to mean metals that have a specific weight of less than 5.0 kg / dm 3 In particular, the specific weight of the light metals is in the range of 1.0 kg / dm 3 up to 3.0 kg / dm 3 .

[0045] The first electrically conductive material of the terminal pin is selected from copper, copper alloy, or CuSiC. CuSiC has a Cu-infiltrated SiC matrix.

[0046] A preferred example comprises a base body made of aluminum or aluminum alloy and a terminal pin with a core made of copper or copper alloy.

[0047] The second electrically conductive material of the terminal pin is selected from aluminum, aluminum alloy, or AlSiC. It is preferably aluminum or an aluminum alloy. The third electrically conductive material of the terminal pin—if present—is preferably selected from aluminum, an aluminum alloy, AlSiC, molybdenum, nickel or nickel alloys, palladium, silver, or gold.

[0048] A preferred example of a terminal pin according to the invention has a core made of copper or copper alloy and a cover material made of aluminum or aluminum alloy.

[0049] However, other material combinations in which a melting point of the second electrically conductive material and / or the third electrically conductive material is advantageously lower than a melting point of the first electrically conductive material of the core of the terminal pin are also advantageous.

[0050] Preferably, the fixing material is a glass, a glass ceramic or a ceramic or comprises a glass, a glass ceramic or a ceramic.

[0051] Preferred glasses include technical glasses, in particular oxide glasses, which are preferably chemically resistant to common materials in connection with electrical energy storage devices.

[0052] In the case of a technical glass, the fixing material is, for example, an aluminum phosphate glass, which contains Al2O S and P2O5, an aluminum borate glass comprising Al2O3 and B2O3, or a bismuth glass comprising, for example, Bi2O3 as the glass former. Alternatively, glasses comprising lead oxide as the glass former, in particular glasses from the PbO-B2O3 system, or vanadium-containing glasses can also be used as the fixing material.

[0053] For glass-to-metal feedthroughs, suitable glasses are selected as the fixing material based on their properties such as melting temperature and / or thermal expansion coefficient. Glasses with a low melting temperature can be advantageous. A glass with a melting temperature below the melting point of aluminum or an aluminum alloy can be particularly advantageous. It can be preferred if, in an electrical feedthrough for an electrical storage device, for example a battery, a capacitor, or a supercapacitor, the fixing material comprises or consists of an aluminum phosphate glass. Suitable glasses are disclosed, for example, in WO 2012 110243 A1 and DE 10 2017 216 422 B3. Alternatively, the fixing material can comprise or consist of a bismuth-based glass comprising Bi2O3 as the glass former, or a lead-based glass comprising PbO as the glass former.

[0054] To produce the electrical feedthrough, the fixing material or a precursor material can be provided in the form of a molded body. The molded body can, for example, be in the shape of a hollow cylinder. To form the electrical feedthrough, the connecting pin is inserted into the interior of this hollow cylinder, which in turn is inserted into an opening in a base body. The connecting pin is inserted into the interior of the hollow cylinder in such a way that the transition from core to cover material lies outside the fixing material. The metal pin is then glazed into the opening through a heat treatment, whereby the fixing material forms an intimate bond with the material of the connecting pin and the material of the base body.

[0055] In an advantageous variant, the base body can have a first thickness d1 outside the area of ​​the through-opening and an increased second thickness d2 in a reinforcement area adjacent to the through-opening with a width W. If the metal-fixing material feedthrough is designed as a pressure glazing, the width W is selected such that sufficient compressive forces can be exerted on the fixing material by the base body.

[0056] This increased thickness of the reinforcement region can be achieved, for example, by providing thickened regions of the base body of the housing part, providing a collar, and / or providing separate reinforcement parts, as disclosed, for example, in WO 2021 / 185648 A1 and also in EP 3 021 377 A2. By selecting the thickness of the base body or providing thickened regions, the glazing length along which the fixing material is bonded to the material of the base body of the housing part can be influenced.

[0057] In one variant, the housing part has a collar forming an inner wall with a height that is greater than the remaining material thickness of the housing part, in particular a thickness of a housing part designed as a lid or a thickness of a wall of a housing part designed as a cup. The collar is preferably designed as a highly arched, formed collar, wherein the housing part and the collar are in particular one-piece.

[0058] To prevent breakage of the glass, ceramic, or glass-ceramic material, particularly after glazing, for example, due to temperature effects, it can be advantageous if the base body comprises a flexible flange for joining the base body to other components, such as parts of a housing. The flange itself comprises a region, a so-called connection region, with which another component is connected to the base body. The connection to the base body can be made by welding, in particular ultrasonic welding or soldering. The welded connection is preferably designed such that the connection is largely gas-tight and preferably has a He leakage rate of less than 10 -8 mbar I / sec at 1 bar pressure difference.

[0059] The flexible flange can be obtained very easily. For example, the base body can be designed as a sheet metal part with a thickness d2, which is stamped down to the thickness d1. After stamping down, the section with the thickness d1 is deformed such that the flexible flange is formed. In this case, the original thickness d2 is retained around the area of ​​the opening so that the area adjacent to the opening is reinforced. It is also possible for a sheet metal with a thickness d1 to be formed into a flexible flange and for the raised sheet metal or a collar formed by forming the sheet metal to accommodate the glazing. Glazing in a raised flexible flange, in particular on a collar of the flexible flange, is particularly possible when the flexible flange and the raised area are made of austenitic steel or duplex steel.

[0060] In an advantageous embodiment, a relief device can be provided in the base body instead of or in addition to a flexible flange. The relief device advantageously comprises at least one groove or recess, preferably at least one circumferential groove or recess. Instead of a groove, a series of adjacent recesses can also be provided.

[0061] The relief device can reduce thermal flow through the base body, thus creating a thermal barrier, and / or reduce mechanical stress on the base body perpendicular to the axis of the connecting pin, since the base body is deformable, preferably reversibly deformable, in the direction perpendicular to the axis of the connecting pin. This results in fewer stresses being introduced into the fixing material, in particular no tensile stresses acting on the fixing material and thus reducing compression on the fixing material, thus improving the tightness of the feedthrough under thermal and mechanical stress.

[0062] In an advantageous first variant, the relief device, in particular a groove or recess, is arranged on the first side of the electrical feedthrough, which faces outward when a housing is formed. In an advantageous alternative second variant, the relief device, in particular a groove or recess, is arranged on the second side of the electrical feedthrough, which faces inward when a housing is formed. In a particularly advantageous third variant, the relief device comprises at least two grooves or recesses arranged on opposite sides of the base body.

[0063] For example, an aluminum phosphate glass with the main components Al2O3, P2O5, and preferably alkali metal oxides, is used as a glass or glass-ceramic material. The thermal expansion coefficient of such a glass material is advantageously in the range of 13 to 25 ppm / K or 13 to 25 10 -61 / K, preferably in the range 13 to 20·10 -6 1 / K, particularly preferably in the range 13 to 18·10 -6 1 / K. If, for example, a bismuth glass is used, the thermal expansion coefficient is approximately 10.5·10- 6 1 / K.

[0064] To achieve a particularly good seal between the metal parts, i.e., the base body and the terminal pin, and the fixing material, the electrical feedthrough can be 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. This permanently exerts compressive forces through the base body on the fixing material. These pre-tension the fixing material and ensure a particularly durable seal.

[0065] Accordingly, it is preferred that a thermal expansion coefficient of the base body is greater than a thermal expansion coefficient of the fixing material.

[0066] In the case of pressure glazing, the thermal expansion coefficient of the base body is particularly preferably selected to be at least 5%, preferably at least 10%, particularly preferably at least 20%, and in some advantageous variants at least 50% greater than the thermal expansion coefficient of the fixing material.

[0067] The prestress for the pressure glazing is essentially determined by the difference in the thermal expansion coefficients between the material of the base body and the fixing material.

[0068] In an advantageous variant with a base body made of light metal or a light metal alloy, the thermal expansion coefficient of the base body is in the range 18·10 -6 1 / K to 30·10 -6 1 / K and the thermal expansion coefficient of the fixing material in the range 13·10 -6 1 / K to 19·10 -61 / K. Such a choice of the thermal expansion coefficient for the fixing material is advantageous for obtaining a pressure glazing when, for example, the base body material is aluminum or an aluminum alloy and the core of the connecting pin is copper or a copper alloy.

[0069] In an advantageous variant with a base body made of steel, in particular austenitic steel or duplex stainless steel, the thermal expansion coefficient of the base body can be in the range 12·10 -6 1 / K to 19·10 -6 1 / K and the thermal expansion coefficient of the fixing material in the range 9·10 -6 1 / K to 11·10 -6 1 / K.

[0070] The thermal expansion coefficient of the glass, ceramic, or glass-ceramic material can be modified if necessary by mixing the glass, ceramic, or glass-ceramic material with a filler. The thermal expansion coefficient can then be adjusted by selecting the type and amount of filler.

[0071] Preferably, the thermal expansion coefficient of the core of the terminal pin is in the range 14·10 -6 1 / K to 19·10 -6 1 / K, advantageous 15·10 -6 1 / K to 18·10 -6 1 / K. Accordingly, the thermal expansion coefficient of the core can be preferably adapted to the thermal expansion coefficient of the fixing material when the penetration is designed as a pressure glazing, or can be selected to be slightly smaller or slightly larger.

[0072] For pressure glazing, for example, a base body made of aluminum or an aluminum alloy with a thermal expansion coefficient of approximately 23 ·10-6 1 / K with an aluminum phosphate glass with a thermal expansion coefficient of approximately 16·10 -6 1 / K and a core made of copper or copper alloy with a thermal expansion coefficient of approx. 16 ·10- 6 1 / K. A combination with a bismuth-based glass with a thermal expansion coefficient of approximately 10.5·10 -6 1 / K can be advantageous for pressure glazing with a base body made of aluminum or an aluminum alloy. A base body made of steel, especially austenitic stainless steel, can also be combined with a bismuth-based glass in a pressure glazing.

[0073] As an alternative to pressure glazing, the thermal expansion coefficient of the base body and the thermal expansion coefficient of the fixing material can be matched. It is preferred if the difference between the thermal expansion coefficients is less than 5%.

[0074] In particular, an adapted implementation is understood to mean that the thermal expansion coefficients essentially change by a maximum of 1 * 10 -6 1 / K, in particular are essentially the same. The thermal expansion coefficient of the core of the connecting pin is preferably adapted in the same way to the thermal expansion coefficient of the fixing material.

[0075] For an adapted implementation, for example, a base body made of steel, in particular austenitic stainless steel, with a thermal expansion coefficient of approximately 16 to 18 10- 6 1 / K, with a suitable glass, in particular an aluminum phosphate glass with a thermal expansion coefficient of approximately 16 ·10- 6 1 / K, and a core made of copper or copper alloy with a thermal expansion coefficient of approx. 16 ·10- 6 1 / K can be combined.

[0076] Where values ​​for the thermal expansion coefficient were mentioned above in connection with pressure glazing or adapted glazing for materials, these refer to the linear thermal expansion coefficient α usually specified in connection with glass-to-metal penetrations in the temperature interval 20-300°C.

[0077] In an advantageous variant, the fixing material has a height and the base body has a thickness in an area adjacent to the through-opening, wherein in a contact area between the base body and the fixing material the height of the fixing material is less than the thickness of the base body. Particularly in connection with pressure glazing it can be advantageous if the height of the fixing material, in particular in relation to a contact area with the base body, is less than the thickness of the base body in this contact area. The fixing material is therefore set back from the base body on at least one side of the through-opening, i.e. there is an offset between the fixing material and the base body. This measure can avoid or reduce pressure peaks directly at the contact between the base body and the edge of the fixing material. This reduces the risk of material damage to the fixing material.In an advantageous variant, the fixing material can be set back on both sides, i.e. on both sides of the feedthrough, preferably by the same amount.

[0078] In such an advantageous embodiment, a surface of the base body adjacent to the through-opening protrudes beyond the fixing material on at least one side of the feedthrough. The base body thus forms a projection on one side of the feedthrough or on both sides of the feedthrough.

[0079] It can be advantageous if the difference, i.e. the difference, between the height of the fixing material and the thickness of the base body amounts to a maximum of 30% in total, preferably a maximum of 26% or a maximum of 24%. An advantageous lower limit for the difference can be 10% or 14% or 16% in total, i.e. the height of the fixing material is, for example, 10 to 30% smaller than the thickness of the base body. The difference can be distributed asymmetrically on both sides of the feedthrough. Advantageously, it is distributed symmetrically on both sides of the feedthrough, so that the fixing material is advantageously set back on each side by at least 5% or at least 7% or at least 8% and / or advantageously by a maximum of 15% or a maximum of 13% or a maximum of 12%.Thus, in an advantageous implementation, there can be an offset between the base body and the fixing material, wherein the fixing material is set back on each side by 5 to 15%, preferably by 8 to 12%, relative to the base body in the area adjacent to the through-opening.

[0080] Typically, a safety valve and / or a predetermined breaking point is provided on housings for energy storage devices as a safety element to relieve excess pressure in the event of internal pressure buildup. The electrical feedthrough preferably has such a safety element. For this purpose, it is preferable to select a press-out force for the terminal pin held by the fixing material such that the terminal pin is pushed out when a predetermined press-out force is exceeded. Such an adjustment of the press-out force is known, for example, from DE 2020 20106 518 U1.

[0081] Preferably, the fixing material and its connection to the wall of the through-hole and the connecting pin are designed in such a way that a safety valve function is provided above a predetermined extrusion force, wherein the predetermined extrusion force is adjusted by one or more of the following measures: a. Selecting the thickness of the glazing, b. Selection of fixing material, c. Selecting the bubble content in the fixation material, d. Structuring the surface of the fixing material by adjusting the shape of a fixing material preform before glazing, e. Structuring the surface of the fixing material during glazing, f. Laser processing of the surface of the fixing material after glazing, g. one- or two-sided insertion of notches or tapers into the fixing material and / or h. Introducing notches or tapers into the terminal pin and / or the base body.

[0082] Preferably, the second electrically conductive material and / or the fixing material are selected such that they are resistant to electrolytes, in particular aqueous and / or non-aqueous electrolytes. In particular, it is preferred if the materials of the feedthrough exhibit high chemical resistance to non-aqueous battery electrolytes, in particular to carbonates, preferably carbonate mixtures with a conductive salt, preferably comprising LiPF6.

[0083] A second aspect of the invention is the provision of a connection pin for an electrical feedthrough, in particular for an electrical feedthrough according to the invention, wherein the connection pin has a cylindrical body or is in the form of a cylindrical body and wherein the connection pin consists of a layered composite material or comprises a layered composite material which has a layer of a first electrically conductive material, preferably selected from copper or a copper alloy, and at least one layer of a second electrically conductive material, preferably selected from aluminum or an aluminum alloy, wherein the layer of the first electrically conductive material forms a core of the connection pin and the at least one layer of the second electrically conductive material forms a covering material on a first end face of the core.

[0084] The cylindrical body of the terminal pin has a lateral surface and two end faces. The core of the cylindrical body forms the layer of the first electrically conductive material. The core, which is advantageously also cylindrical, has two end faces that lie opposite one another, with at least one end face being covered with a layer of the second electrically conductive material, i.e., covering material.

[0085] The connecting pin preferably has a circular cylindrical shape. In addition to circular cylindrical shapes, general cylindrical shapes with other end shapes are also conceivable. For example, oval shapes or rectangles with rounded corners are conceivable.

[0086] In an advantageous embodiment, the connecting pin has a length of 2 mm to 8 mm, preferably of 3 mm to 6 mm.

[0087] In an advantageous embodiment, the connecting pin has a diameter of 1 mm to 20 mm, preferably of 2 mm to 10 mm.

[0088] In the context of the invention, "core" is understood to mean a section of the connecting pin which - based on a longitudinal axis of the connecting pin - preferably makes up at least 50% of the length. Advantageously, the core forms the main part of the connecting pin and makes up more than 50%, advantageously at least 55% or at least 60% of the length of the connecting pin. The longitudinal axis of the connecting pin extends in a direction parallel to the axis of the through-opening. In the case of a substantially flat base body, the longitudinal axis of the connecting pin extends correspondingly perpendicular to a plane of the base body in which the through-opening is formed. In the case of a layered composite material, the thickness of the covering material can preferably be at least 10% of the length of the connecting pin.

[0089] Advantageously, the connecting pin is a plated, preferably roll-clad, connecting pin, i.e., a connecting pin made of a layered composite material produced by plating, preferably by roll-cladding. The layered composite material may, for example, be in the form of a strip or plate. Details of this are described above in connection with the first aspect of the invention.

[0090] Details regarding the advantageous lengths and thicknesses of the core and / or cover material were described in detail above in connection with the first aspect of the invention. The thickness of the cover material is at least large enough to create a continuous cover layer free of openings and defects in the plated layered composite material. Furthermore, the thickness of the cover material depends on the current-carrying capacity of the terminal and the desired method by which additional connections are to be connected to the cover layer.

[0091] Preferably, the connecting pin is separated from the layered composite material by means of a separation process, in particular by dividing, preferably by cutting out, such as laser cutting, water jet cutting, or shear cutting, which was described in detail above in connection with the first aspect of the invention. In an advantageous embodiment, this is a cut, preferably punched connecting pin.

[0092] In a particularly advantageous embodiment, the connecting pin is a stamped, roll-clad connecting pin, i.e., during production, the connecting pin is made from a roll-clad laminated composite material by shear cutting with a closed cutting line, particularly using cutting punches, cutting dies, and presses. Such connecting pins can be produced economically in large quantities.

[0093] Further details, advantageous developments and advantages of the connecting pin - e.g. geometric, structural features, materials, additional cover material, etc. - as well as its manufacture have already been described above in connection with the first aspect of the invention, so that in order to avoid repetition, reference is made to the above explanations.

[0094] A third aspect of the invention relates to the use of a terminal pin according to the invention in an electrical feedthrough, in particular in an electrical feedthrough according to the invention. A cylindrical body or an object having a cylindrical body, wherein the cylindrical body consists of a layered composite material or comprises a layered composite material, is used as a terminal pin in an electrical feedthrough. The layered composite material has a layer of a first electrically conductive material, preferably selected from copper or a copper alloy, and at least one layer of a second electrically conductive material, preferably selected from aluminum or an aluminum alloy.The layer of the first electrically conductive material forms a core of the terminal pin and the at least one layer of the second electrically conductive material forms a covering material on a first end face of the core.

[0095] In an advantageous variant, a cut-out, plated terminal pin is used. A stamped, roll-plated terminal pin is particularly preferred.

[0096] Further details, advantages and advantageous developments of a connection pin and a feedthrough have already been described above in connection with the first aspect and the second aspect of the invention, so that in order to avoid repetition, reference is made to the above explanations.

[0097] A further aspect of the invention is the provision of an electrical storage device. The proposed electrical storage device is designed, in particular, as a battery or as a capacitor, including a supercapacitor, and comprises a housing with at least one of the electrical feedthroughs described herein and / or with a connection pin described herein. Furthermore, the electrical storage device preferably comprises at least one storage cell, in particular a battery cell or a capacitor cell.

[0098] The base body of the electrical feedthrough is preferably designed as a housing part, in particular as a cover or as a component of a cover, which is preferably hermetically sealed to other housing parts, so that a hermetically sealed housing for the electrical storage device is formed. For example, to form the housing, a cover is connected to the electrical feedthrough by welding to a cup part. Hermetically sealed is understood here to mean that the housing has a He leakage rate of less than 10 -8 mbar I / sec at 1 bar pressure difference.

[0099] The invention will be described in more detail below with reference to the schematic figures and without limitation thereto.

[0100] They show: Fig. 1 shows a first embodiment of an electrical feedthrough with a one-sided flush design of the connecting pin, Fig. 2 second embodiment of an electrical feedthrough with surfaces of the connecting pin projecting beyond a base body and a recessed fixing material, Fig. 3 a third embodiment of an electrical feedthrough with double-sided coverage of the core of the connecting pin and a reinforcement area, Fig. 4 a fourth embodiment of an electrical feedthrough with a flexible flange, Fig. 5 a fifth embodiment of an electrical feedthrough with a fully coated core of the connecting pin, Fig. 6 a sixth embodiment of an electrical feedthrough with a flexible flange, Fig. 7 a seventh embodiment of an electrical feedthrough with a relief device and a recessed fixing material and Fig. 8 a cross section through an embodiment of a connection pin.

[0101] In Fig. 1 shows a first embodiment of an electrical feedthrough 10. The electrical feedthrough 10 comprises a base body 12 with a through-opening 14 into which a terminal pin 20 with a longitudinal axis L is inserted. The terminal pin 20 is held in the through-opening 14 in an electrically insulating manner by a fixing material 16. The fixing material 16 seals both against an inner wall of the through-opening 14 and against the terminal pin 20, so that the through-opening 14 is tightly closed by the fixing material 16, and a metal fixing material feedthrough is formed.

[0102] The illustrated electrical feedthrough 10 is particularly suitable for use in connection with electrical storage devices such as batteries, in particular microbatteries, and capacitors. Accordingly, the base body 12 can be a component of a housing for such an electrical storage device, for example a battery cover or a component of a battery cover. The connection pin 20 then forms, for example, a connection terminal of the electrical storage device. To form a housing for the electrical storage device, the base body 12 of the electrical feedthrough is joined to other housing parts. If the base body 12 is designed as a cover part, a housing for an electrical storage device can be formed by joining the cover part to a cup part.Typically, at least one storage cell, such as a battery cell or a capacitor cell, is arranged inside such a storage device. To establish an electrical connection, one terminal of such a storage cell can be electrically connected to the terminal pin 20, and another terminal can be electrically connected to another housing part. Of course, it is also possible to form a plurality of through-openings 14 in a base body 12 and to arrange a plurality of terminal pins 20, thus providing a multi-pole feedthrough.

[0103] The connecting pin 20, which here is in the form of a cylindrical body, must be adapted in its material properties, particularly with regard to its thermal expansion coefficient, to the requirements of the metal-fixing material feedthrough formed. To prevent or at least reduce corrosion of the connecting pin 20, the material of the connecting pin 20 should also be adapted to the materials used in the storage cell, such as the current collector materials, electrode materials, and electrolytes.To meet both requirements, the invention provides that the terminal pin 20 has a core 22 made of copper, copper alloy, or CuSiC as the first electrically conductive material, which is adapted to the requirements of the metal fixing material feedthrough, and a cover material 24, which covers an end face of the core 22, made of aluminum, aluminum alloy, or AlSiC as the second electrically conductive material, which has different functions depending on the arrangement on the side facing outwards or inwards when forming a housing. When arranged on the outwards-facing side, it optimizes the terminal pin 20 with regard to simple and secure contacting due to its good welding or soldering properties.When arranged on the inward-facing side, it can further optimize the connection pin 20 with regard to chemical resistance to materials of the memory cell and electrochemical potentials or also serve to improve contactability.

[0104] The connecting pin 20 and the fixing material 16 are designed and arranged in the electrical feedthrough 10 such that a transition 26a from the core 22 to the covering material 24 lies outside the fixing material 16, wherein the fixing material 16 only borders the core 22 and thus has no laterally contact with the covering material. Because the transition 26a, i.e. the material boundary, between the core 22 and the covering material 24 lies outside the fixing material 16, a particularly stable feedthrough is achieved, since different thermal expansion behaviors of the two electrically conductive materials do not affect the contact area between the connecting pin and the fixing material, which could otherwise lead to a weakening of the feedthrough.

[0105] The second electrically conductive material can be applied, for example, to the end face of the core 22 of the terminal pin 20 by plating, as described further below. However, other variants for applying the second electrically conductive material are also conceivable. For example, thin sheets or foils made of the second electrically conductive material can be connected to the core 22 by welding or soldering, or the second electrical material can be applied by galvanic coating or a vapor deposition process.

[0106] In the first embodiment of the Fig. 1, a lateral surface of the core 22 of the connection pin 20 remains free of the covering material 24, so that the fixing material 16 directly borders the core 22 or its lateral surface. This ensures that the fixing material 16 can be in direct contact with the core 22 and the covering material 24 does not change the properties of the metal fixing material feedthrough. The two materials of the connection pin 20 can thus each be selected completely independently of one another in order to achieve optimal adaptation to the requirements of the storage cells inside the housing, to the formation of the metal fixing material feedthrough and to the connection to electrical connections, i.e. to the contactability of the connection pin. For example, in the case of an embodiment of the electrical feedthrough 10 for use in a lithium-ion battery, the metal fixing material feedthrough can be designed as a pressure glazing.

[0107] In dem in Fig. In the embodiment of the electrical feedthrough 10 shown in Figure 1, one end face of the connection pin 20 is flush with the corresponding surfaces of the base body 12, while the other end face of the connection pin 20 protrudes beyond the corresponding surface of the base body 12. The total thickness of the connection pin 20 is thus greater than the thickness of the base body 12. A surface of the fixing material 16 is flush with an end face of the connection pin 20. In addition, the surfaces of the fixing material 16 are flush with the surfaces of the base body 12, i.e. - with respect to a contact area with the base body - the height H of the fixing material is essentially the same as the thickness D of the base body 12 in an area adjacent to the through-opening 14. However, it can also be advantageous if the height H of the fixing material 16 is less than the thickness D of the base body 12, which is exemplified in the Fig. 2 and Fig. 7. However, it would also be conceivable for the fixing material 16 to protrude beyond the surfaces and partially cover adjacent areas of the connecting pin 20 and / or the base body 12. Furthermore, it is alternatively conceivable for both end faces of the connecting pin 20 to protrude beyond the corresponding surfaces of the base body 12. This is shown by way of example in Fig. 2 shown.

[0108] In Fig. 1 shows an advantageous embodiment of a connecting pin 20 according to the invention for an electrical feedthrough in cross section (see also Fig. 8). The terminal pin 20 is in the form of a cylindrical body. It comprises a layered composite material having a layer of a first electrically conductive material and at least one layer of a second electrically conductive material, wherein the layer of the first electrically conductive material forms a core 22 of the terminal pin, and the at least one layer of the second electrically conductive material forms a covering material 24 on an end face of the core 22. Relative to a longitudinal axis L of the terminal pin 20, the thickness or length of the core 22 here accounts for approximately 80% of the length of the terminal pin 20, and the thickness or length of the covering material 24 thus accounts for approximately 20%.

[0109] In the illustrated embodiment, the terminal pin 20 is a roll-clad terminal pin made of a roll-clad composite material comprising a layer of copper or a copper alloy forming the core 22 and at least one layer of aluminum or an aluminum alloy forming the cover material 24. The terminal pin 20 shown is, by way of example, a stamped, roll-clad terminal pin.

[0110] The following figures show the same components as in the Fig. 1 are given the same reference numerals.

[0111] Fig. 2 shows a second embodiment of the electrical feedthrough 10 with end faces or surfaces of the terminal pin 20 projecting beyond the base body 12. The structure of the electrical feedthrough 10 corresponds to that described with reference to Fig. 1 described first embodiment. Deviating from this, the connecting pin 20 is designed and arranged such that its end faces are not flush with the corresponding surfaces of the base body 12. The total thickness of the connecting pin 20 is also greater than the thickness of the base body 12. Compared to Fig. 1, the thickness of the covering material 24 is chosen to be greater. Such a layered composite structure can be produced, in particular, by plating.

[0112] In Fig. 2 also shows that the height H of the fixing material 16a, which here also corresponds to the glazing length for the connecting pin, is less in the contact area with the base body than the thickness D of the base body 12 in an area adjacent to the through-opening 14. The fixing material 16a is thus set back with respect to the base body 12, i.e. there is an offset 27. A particularly advantageous embodiment is shown in which the fixing material 16a is set back on both sides by approximately the same amount, relative to the thickness of the base body 12 in the area of ​​the through-opening 14. By means of this measure, pressure peaks directly at the contact between the base body and the edge of the fixing material can be avoided or reduced in the event of pressure glazing. This reduces the risk of material damage to the fixing material.

[0113] It is of course conceivable that in the case of a feedthrough with recessed fixing material 16a, one of the two end faces of the connecting pin 20 is arranged flush with the corresponding surface of the base body 12, so that the connecting pin 20 protrudes beyond the base body 12 on only one of the two sides, as for example in Fig. 1. A one-sided flush arrangement of the end face of the terminal pin with the corresponding surface of the recessed fixing material would also be possible. Furthermore, it is possible to provide a recessed fixing material 16a with a height H in the through-hole with a reinforced base body corresponding to the Fig. 3, Fig. 4 and Fig. 6. For such base bodies, the thickness d2 corresponds to the reference size D.

[0114] In Fig. 3 shows a third embodiment of the electrical feedthrough 10. As with reference to the first embodiment of the Fig. 1, the electrical feedthrough 10 has a base body 12 with a through-opening 14 in which a connection pin 20 is held in an insulating manner by means of a fixing material 16.

[0115] Deviating from the first embodiment of the Fig. 1, a further covering material 25 made of a third electrically conductive material is additionally arranged on a second end face of the core 22, so that both end faces of the core 22 of the connecting pin 20 are covered with covering material 24, 25. It can be seen that the further transition 26b, i.e. the material boundary, between the core 22 and the further covering material 25 is advantageously located outside the fixing material 16, thereby providing a particularly stable feedthrough, since different thermal expansion behaviors of the different materials of the connecting pin do not affect the contact area between the connecting pin and the fixing material, which could otherwise lead to a weakening of the feedthrough.Alternatively, however, it would also be possible to position this further transition 26b in the contact area with the fixing material 16, so that in this embodiment the first material of the core 22 is inaccessible on one side of the feedthrough (see e.g. Fig. 4 and Fig. 6). The third electrically conductive material can be selected to be different from or identical to the second electrically conductive material. Identical materials are shown as examples, i.e., the third electrically conductive material is selected here from aluminum, an aluminum alloy, or AlSiC. The thicknesses of cover material 24 and cover material 25 can be the same, as shown, or different.

[0116] In the third embodiment of the Fig. 3, the base body 12 is also designed differently from the first two embodiments. The base body 12 of the third embodiment has a reinforcement region with a width W, which borders the through-opening 14 and within which the base body 12 has an increased thickness d2. Outside the reinforcement region, the base body 12 has the smaller thickness d1. This results in a particularly compact design of the electrical feedthrough 10, which is particularly suitable for microbatteries. Nevertheless, the base body 12 offers high mechanical stability, which is also suitable for forming the metal fixing material feedthrough as a pressure glazing. For this purpose, the width W is selected such that the required compressive forces can be built up.

[0117] The design of the base body 12 with a reinforcement area can of course be combined with other embodiments, so that, for example, deviating from the representation of the Fig. 3 an end face of the connecting pin 20 is arranged flush with a surface of the base body 12 adjacent to the through-opening 14 (see Fig. 4) or only a first end face of the core 22 is covered with a covering material 24. A design with a recessed fixing material 16a, for example according to Fig. 2, would be possible.

[0118] Fig. 4 shows a fourth embodiment of an electrical feedthrough 10. As with reference to the first embodiment of the Fig. 1, the electrical feedthrough 10 has a base body 12 with a through-opening 14 in which a terminal pin 20 is held in an insulating manner by means of a fixing material 16. The core 22 of the terminal pin 20 is, as in the third embodiment of the Fig. 3, is provided with cover material 24, 25 on both of its end faces, wherein in the example shown, one end face of the terminal pin is flush with a surface of the base body 12 adjacent to the through-opening 14. As can be seen in the figure, in this example, the additional cover material 25 with the third electrically conductive material is selected to be different from the cover material 24 with the second electrically conductive material. As can be seen, the transition 26a from the core 22 to the cover material 24 lies outside the fixing material 16, while on the opposite side of the feedthrough 10, the additional transition 26b from the core 22 to the additional cover material 25 is arranged within the fixing material 16, i.e., the fixing material 16 directly borders laterally on the core 22 and additional cover material 25.With such a design, a stable feedthrough can be achieved, especially when the difference between the thermal expansion coefficients of the first and third electrically conductive material is small.

[0119] The base body 12 of the fourth exemplary embodiment additionally comprises a flexible flange 30, via which it can be connected to further elements, for example to further components of a housing. The flexible flange 30 is obtained, for example, by forming the base body 12 and has a transition region with a width W, within which a flat section of the base body 12 transitions into a glazing section with a thickness d2 that is greater than the thickness d1 of the flat section of the base body 12. The base body 12 is flexible and yielding in the transition region, so that the area with the through-opening 14 is mechanically decoupled by the flexible flange 30. Accordingly, mechanical stresses from other parts of the housing are not transferred to the fixing material 16.Furthermore, the thickness d2 within the glazing section can be freely selected within a wide range, allowing the glazing length to be adjusted independently of other dimensions of the base body 12 or a housing comprising the base body. Of course, a base body 12 with a flexible flange 30 could also be combined with a connecting pin 20 in which only one end face has a covering material.

[0120] Fig. 5 shows a fifth embodiment of an electrical feedthrough 10, which is similar to the first embodiment of the Fig. 1, wherein, however, both end faces of the terminal pin 20 protrude beyond the corresponding surfaces of the base body 12. Deviating from the first embodiment, the core 22 of the terminal pin 20 made of copper, copper alloy or CuSiC is completely surrounded by aluminum, an aluminum alloy or AlSiC, so that all surfaces of the core 22 are covered by the covering material 24. Accordingly, in particular both end faces and a lateral surface of the core 22 are covered by the covering material 24. The fixing material 16 also borders on the core 22 here, ie it is arranged at the level of the core, but without directly contacting it, unlike the other Fig. 1 to 4, 6 and 7, in which the fixing material is in direct contact with the core, ie directly adjacent to the core or to the outer surface of the core 22.

[0121] Fig. 6 shows a sixth embodiment of an electrical feedthrough 10, which is similar to the fourth embodiment of the Fig. 4 and comprises a flexible flange 30, the design and function of which have already been described above. The core 22 of the terminal pin 20 with the first electrically conductive material is, as in the fourth embodiment of the Fig. 4, is provided on both of its end faces with covering material 24, 25, wherein, for example, the covering materials 24, 25 are identical, but their thicknesses are selected to be different. Since the further transition 26b between core 22 and further covering material 25 is in contact with the fixing material here, the thickness of covering material 25 is selected to be smaller. Deviating from the fourth exemplary embodiment, the connecting pin 20 is designed and arranged such that its two end faces are not arranged flush with the corresponding surfaces of the base body 12, but rather protrude beyond them. The total thickness of the connecting pin 20 is thus greater than the thickness of the base body 12 in the area of ​​the feedthrough. In the Fig. 6 that the arrangement of the core 22 and the thickness of the covering material 25 are selected to be so large that, in conjunction with the fixing material 16, the first electrically conductive material of the core 22 is not accessible from one side of the electrical feedthrough 10. Accordingly, the fixing material 16 also directly borders the covering material 25. The covering material 25 is located on the second side of the electrical feedthrough 10, which faces inwards when a housing is formed. On the opposite first side of the feedthrough 10, which faces outwards when a housing is formed, the first electrically conductive material of the core 22 is accessible in the exemplary embodiment shown, since the transition 26a from the core 22 to the covering material 24 lies outside the fixing material 16.

[0122] Fig. 7 shows a seventh embodiment of an electrical feedthrough 10, which is similar to the second embodiment of the Fig. 2. However, the base body 12 of the seventh exemplary embodiment has a circumferential connecting flange 32 on its outer edge, which is designed here in the form of a one-sided step. The connecting flange 32 can serve to align and center the base body 12 with respect to another housing component—for example, a cup-shaped housing element or a cover element—during the assembly of a housing or cover. Furthermore, the connection to the other housing component can be made at the connecting flange 32, for example, by means of a welded or soldered connection. A connecting flange can also be combined with other base body designs, for example, with reinforcements or a flexible flange.

[0123] Furthermore, in the seventh exemplary embodiment, a relief device 31 is provided in the base body 12, which is designed here, for example, as a groove or recess, preferably as a circumferential groove or circumferential recess. The groove of the relief device 31 is arranged, for example, on the first side of the electrical feedthrough 10, which faces outward when a housing is formed. Of course, it could also be arranged on the other side of the housing. Two grooves or recesses arranged on opposite sides of the base body can also serve as the relief device 31. Instead of a groove, a series of adjacent recesses can also be provided.

[0124] The relief device 31 reduces thermal flow through the base body 12, thus creating a thermal barrier, and / or reduces mechanical stress on the base body 12 perpendicular to the longitudinal axis of the terminal pin 20, since the base body 12 is deformable, preferably reversibly deformable, in the direction perpendicular to the longitudinal axis of the terminal pin 20. This results in fewer stresses, in particular no tensile stresses, being introduced into the fixing material 16, which act on the fixing material 16 and thereby reduce the compression on the fixing material 16, thereby ensuring the tightness of the feedthrough 10 under thermal and / or mechanical stresses. The fixing material here is a recessed fixing material 16a, which, as in connection with the second exemplary embodiment (see Fig. 2) is described, designed and arranged. Of course, a relief device 31 can also be realized in other embodiments of the invention, for example an embodiment according to Fig. 1, in which the height H of the fixing material is substantially equal to the thickness D of the base body 12 in an area adjacent to the through opening 14.

[0125] In a particularly advantageous embodiment of the seventh exemplary embodiment, the terminal pin 20 has a core 22 made of copper as the first electrically conductive material and, on an end face of the core 22, a covering material 24 made of aluminum as the second electrically conductive material. Alternatively, it could also be a core made of a copper alloy and / or a covering material made of an aluminum alloy.

[0126] The connecting pin 20 shown is advantageously a stamped, roll-plated connecting pin.

[0127] The base body 12 consists of a material with a thermal expansion coefficient that is higher than that of the material of the core 22. In particular, the base body 12 is made of aluminum or an aluminum alloy. By selecting a low-melting fixing material 16 with a thermal expansion coefficient that is lower than the thermal expansion coefficient of the base body 12, a hermetically sealed pressure glazing can be provided in combination with a base body 12 made of aluminum or an aluminum alloy. The fixing material 16 can be, for example, a bismuth-based glass. It is advantageously an aluminum phosphate glass.

[0128] Even with a steel base body, pressure glazing can be provided if the fixing material is chosen accordingly, since the prestress for the pressure glazing is essentially determined by the difference in the thermal expansion coefficients between the material of the base body and the material of the fixing material.

[0129] Alternatively, the materials of the base body 12 and the fixing material 16, 16a and, if applicable, the core 22 can be adapted to one another with regard to their thermal expansion coefficients, so that an adapted implementation is provided.

[0130] If the core 22 is made of copper or, alternatively, a copper alloy, the connecting pin 20 is adapted to the requirements of the formed metal-fixing material feedthrough with regard to its material properties, in particular with regard to its thermal expansion coefficient. At the same time, such a core 22 is also chemically resistant and thus adapted to the requirements of the materials of a storage cell, e.g., chemical resistance, electrochemical potentials, so that corrosion of the connecting pin 20 is prevented or at least reduced. Consequently, it is not absolutely necessary to provide an additional covering material on the second end face of the core 22, which faces inward when forming a housing.

[0131] Since the core 22 is provided with a cover material 24 made of aluminum or, alternatively, an aluminum alloy on its first end face, which faces outward when a housing is formed, the terminal pin 20 can be optimized, for example, for simple and secure connection, e.g., soldering or welding, to electrical connections. Even if the cover material 24 made of aluminum or aluminum alloy is located on the side facing inward when a housing is formed, this can improve contactability with electrical connections.

[0132] The advantageous material combinations mentioned in connection with the seventh embodiment can also be advantageous for other embodiments, for example designs with and without relief device 31, with and without reinforcement measures, with flush arrangement of the fixing material, etc.

[0133] Appendix of Fig.8, the terms used in connection with the above description of the connection pins 20 are clarified again.

[0134] The connecting pin 20 is exemplified here in the form of a cylindrical body and has a peripheral surface 21c and two end faces 21a, 21b. The core 22 of the cylindrical body, which is also cylindrical here, has two end faces 23a, 23b that lie opposite one another and a peripheral surface 23c that forms a portion of the peripheral surface 21c of the connecting pin. As can be seen, a first end face 23a of the core 22 is covered with the covering material 24.

[0135] In the example shown, the terminal pin 20 is designed such that no further layer is present on the second end face 23b of the core 22. Thus, the second end face 23b of the core 22 simultaneously forms the end face 21b of the terminal pin.

[0136] Although the present invention has been described with reference to preferred embodiments, it is not limited thereto, but can be modified in many ways, in particular by combining the features described with reference to different embodiments (such as design of the base body - with reinforcement device, relief device, flexible flange -, design and arrangement of the fixing material, design and arrangement of the connecting pin, choice of materials of the components) to form further examples that make use of the technical teaching of the invention. List of reference symbols 10 electrical feedthrough 12 basic bodies 14 passage opening 16 Fixing material 16a recessed fixing material 20 connection pins 21a front side of 20 21b Front side of 20 21c lateral surface of 20 22 core 23a first end face of 22 23b second end face of 22 23c lateral surface of 22 24 Covering material 25 additional covering material 26a Transition 26b further transition 27 Offset 30 flexible flange 31 relief device 32 connecting flange d1 first thickness for a reinforced base body d2 second thickness for a reinforced base body D Thickness of 12 in the area of ​​the through hole HW height of 16 width L Longitudinal axis of 20 QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Zitierte Patentliteratur

[0000] EP 2 371 419 A2

[0006] US 2014 / 212741 A1

[0007] WO 2016 / 074932

[0008] WO 2021 / 185648 A1 [0009, 0056] WO 2012 110243 A1

[0053] DE 10 2017 216 422 B3

[0053] EP 3 021 377 A2

[0056] DE 2020 20106 518 U1

[0080]

Claims

[1] Electrical feedthrough (10), in particular for an electrical storage device, comprising a base body (12) with a through-opening (14) and a connecting pin (20) arranged in the through-opening (14) which is held in an electrically insulating manner in the through-opening (14) by means of a fixing material (16), characterized by in that the connecting pin (20) has a core (22) made of copper or a copper alloy or CuSiC as the first electrically conductive material and at least on a first side of the electrical feedthrough (10) has a covering material (24) made of aluminum or an aluminum alloy or AlSiC as the second electrically conductive material, which covers a first end face (23a) of the core (22), wherein the connecting pin (20) and the fixing material (16) are designed and arranged such that a transition (26a) from the core (22) to the covering material (24) lies outside the fixing material (16). [2] Electrical feedthrough (10) according to claim 1, wherein a lateral surface (23c) of the core (22) facing the fixing material (16) is at least partially not covered with covering material (24, 25) and directly adjoins the fixing material (16). [3] Electrical feedthrough (10) according to claim 1 or 2, characterized by that a melting temperature of the fixing material (16) is selected to be lower than the melting point of all materials of the connecting pin (20). [4] Electrical feedthrough (10) according to one of claims 1 to 3, characterized by that the second electrically conductive material is applied to the end face of the core (22) by means of plating, electroplating, coating, vapor deposition, welding or soldering. [5] Electrical feedthrough (10) according to one of claims 1 to 4, characterized bythat the terminal pin (20) is a plated terminal pin which consists of a plated layered composite material or comprises such a layered composite material which has a layer of copper or a copper alloy and at least one layer of aluminum or an aluminum alloy. [6] Electrical feedthrough (10) according to one of claims 1 to 5, characterized by that the fixing material (16) has a height (H) and the base body (12) has a thickness (D, d2) in a region adjacent to the through opening (14), wherein in a contact region between the base body (12) and the fixing material (16) the height (H) is less than the thickness (D). [7] Electrical feedthrough (10) according to one of claims 1 to 6, characterized by that an end face (21a, 21b) of the connecting pin (20) is arranged flush with a surface of the base body (12). [8] Electrical feedthrough (10) according to one of claims 1 to 7, characterized bythat one end face (21a, 21b) or both end faces (21a, 21b) of the connecting pin (20) are arranged to project beyond a surface of the base body (12). [9] Electrical feedthrough (10) according to one of claims 1 to 8, characterized by that the material of the base body (12) is selected from light metal, light metal alloy, AlSiC, steel, in particular ferritic, austenitic or duplex steel, stainless steel, stainless steel, tool steel. [10] Electrical feedthrough (10) according to one of claims 1 to 9, characterized by that the fixing material (16) is a glass, a glass ceramic or a ceramic or that the fixing material (16) comprises a glass, a glass ceramic or a ceramic. [11] Electrical feedthrough (10) according to one of claims 1 to 10, characterized bythat a first thermal expansion coefficient of the base body (12) is greater than a second thermal expansion coefficient of the fixing material (16) or that the thermal expansion coefficients of the base body (12) and the fixing material (16) are adapted to one another. [12] Electrical feedthrough (10) according to one of claims 1 to 11, characterized by that the base body (12) has a relief device (31). [13] Connection pin (20) for an electrical feedthrough (10), in particular for an electrical feedthrough (10) according to one of claims 1 to 12, wherein the connection pin (20) has a cylindrical body or is in the form of a cylindrical body and wherein the connection pin (20) consists of a layered composite material or comprises a layered composite material which has a layer of a first electrically conductive material, preferably selected from copper or a copper alloy, and at least one layer of a second electrically conductive material, preferably selected from aluminum or an aluminum alloy, wherein the layer of the first electrically conductive material forms a core (22) of the connection pin (20) and the at least one layer of the second electrically conductive material forms a covering material (24) on a first end face (23a) of the core (22). [14] Connecting pin (20) according to claim 13, characterized by that the core (22) makes up at least or more than 50%, advantageously at least 55%, preferably at least 60% of the length of the connecting pin (20). [15] Terminal pin (20) according to one of claims 13 or 14, characterized by that it is a plated, preferably roll-plated, connecting pin (20). [16] Terminal pin (20) according to one of claims 13 or 15, characterized by that it is a cut, preferably punched, connecting pin (20). [17] Use of a terminal pin (20) according to one of claims 13 to 16 in an electrical feedthrough, in particular according to one of claims 1 to 12. [18] Electrical storage device, in particular a battery or a capacitor, comprising a housing with at least one electrical feedthrough (10) according to one of claims 1 to 12 and / or with a connection pin (20) according to one of claims 13 to 16.

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