WO2024240821A1 - Housing part with an electrical bushing for an electrical device, and energy store with such a housing part - Google Patents

Abstract

In a housing part (10), in particular for an electrical storage device, having an electrical bushing comprising a main body (12) with a passage opening (14) and comprising a connection pin (20) which is arranged in the passage opening (14) and is held in the passage opening (14) by means of a fixing material (16) such that it is electrically insulated, the intention is to reduce the expenditure on manufacture and the risk of misalignment of the components. For this purpose, it is proposed that the main body (12) of the housing part (10) is flat and disc-like with a substantially uniform thickness (D) and a height (H) of the fixing material (16) is greater than the thickness (D) of the main body (12), wherein (i) the main body (12) has a symmetrical bushing, by way of the fixing material (16) and the connection pin (20) being arranged symmetrically with respect to a plane of symmetry (S) situated centrally in the plane of the main body, and/or (ii) the main body (12) has, on its outer edge (17), a symmetrical connecting flange (18b), which is arranged symmetrically with respect to a plane of symmetry (S) situated centrally in the plane of the main body.

Description

Housing part with electrical feedthrough for an electrical device and energy storage device with such a housing part

The invention relates to a housing part for an electrical device, in particular for an electrical energy storage device, in particular a battery, preferably a microbattery, a capacitor, with an electrical feedthrough, comprising a base body with a through-opening and a connection pin arranged in the through-opening, which is held in the through-opening in an electrically insulating manner by means of a fixing material. A further aspect of the invention relates to an electrical energy storage device which comprises such a housing part with at least one feedthrough.

Electrical energy storage devices - also called electrical storage devices - such as batteries or capacitors, the latter including supercapacitors, are used in a variety of applications for storing and providing electrical energy. The electrical energy storage devices usually comprise a housing and at least one storage cell accommodated in the housing. For this purpose, the housing often comprises a cup-shaped housing element. Another component of the housing is a housing part with at least one electrical feedthrough, via which the storage cell can be electrically contacted from the outside. The housing part can form the cover or cover part of an electrical storage device or be part of a cover or cover part.

Batteries in the sense of the invention are understood to be both a disposable battery that can be disposed of and/or recycled after it has been discharged and also 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. The batteries can replace traditional energy sources such as lead Replace acid batteries, nickel-cadmium batteries or nickel-metal hydride batteries. The battery can also be used in sensors or in the Internet of Things.

Supercapacitors, also called supercaps, are, as is well known, electrochemical energy storage devices with a particularly high power density. Unlike ceramic, film and electrolytic capacitors, supercapacitors do not have a dielectric in the traditional sense. In particular, they implement the storage principles of static storage of electrical energy through charge separation in a double-layer capacitance and the electrochemical storage of electrical energy through charge exchange with the help of redox reactions in a pseudocapacitance.

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

The basic principle of an electrical feedthrough in an electrical device is that a connection pin is held in an electrically insulating manner by a fixing material in a through hole formed in a base body. The term connection pin is generally used here for a functional element, which can be an electrical conductor, for example.

In the case of an electrical storage device, a stable, tight leadthrough of the connection pin over a long period of time and, for example, in the event of an accident is particularly necessary in order to prevent the leakage of, for example, battery electrolytes from the interior of the electrical storage device. Therefore, the Base bodies with a through-hole have a large material thickness in order to achieve tightness and stability over a large contact length between the wall of the through-hole of the base body and the fixing material, which results in large, relatively heavy storage devices with large dimensions, for example heights. Housing parts with a large material thickness, however, lead to a small volume inside the housing, for example of a storage device.

DE 10 2014 016 601 A1 shows a housing component, in particular a battery housing or capacitor housing with a feedthrough, wherein a pin-shaped conductor in a glass or glass ceramic material is passed through a through-opening, wherein the housing component has a reinforcement in the area of the through-opening, while the rest of the housing component is made thinner. In this way, weight can be saved and a stable, tight feedthrough can still be provided.

When it comes to electrical devices, especially electrical storage devices, the trend is towards smaller and more compact versions with low housing material thicknesses, whereby small, compact electrical storage devices are also called micro batteries. However, the problem with low housing material thickness is ensuring a tight, stable passage for the connection pin.

W02020/104571 A1 shows an electrical storage device as a micro battery with a feedthrough, wherein the feedthrough is embedded in a battery cover part with a formed collar. A flexible flange is also disclosed in the area of the feedthrough. Formed collar and flexible flange represent two possibilities for providing a greater contact length for the fixing material in a thin housing part or base body despite the low material thickness in the area of the through-opening. A microbattery is known from WO2021/185648 A1, which is characterized by a particularly compact design. The metal fixing material feedthrough provided in the base body for an electrical connection of the microbattery can be designed as a pressure glazing, so that a particularly reliable sealing of the feedthrough is achieved. In the microbattery shown in WO2021/185648 A1, a reinforcement, a formed collar or a formed base body with a flexible flange are also used in the area of the feedthrough in order to stabilize the housing part and to provide reliable electrical insulation of the connection pin introduced into the through-opening by forming a longer contact length for the fixing material in the through-opening of the base body.

Due to areas of the base body protruding from a housing part plane - such as reinforcement, collar or flexible flange - the geometric design of the top of the housing part differs from the geometric design of the bottom of the housing part, i.e. the housing part is asymmetrical with regard to the feedthrough - comprising the through hole in the base body, the fixing material, the connection pin - in relation to a plane of symmetry lying in the housing part plane. With the help of areas protruding from the housing part plane, in particular parts of the base body, it is possible to distinguish between the top and bottom of the base body or housing part. This enables the individual parts of the housing part to be securely aligned for the production of the electrical feedthrough and/or for the production of a cover or housing. However, due to the protruding areas, such housing parts require space that must be structurally accommodated inside the housing or outside the electrical device.

In order to gain installation space inside the housing or to reduce the height of electrical equipment, housing parts are increasingly being sought that provide a tight feedthrough of a connection pin even without reinforcing elements such as reinforcement, collar or flexible flange. For example, WO 2021/185649 A1 teaches how to glaze a conductor over a glass or glass ceramic material in the through hole of a thicker base body in order to create a tight connection between the connection pin, fixing material and base body. The entire feedthrough created is then reduced in thickness by machining on one or both sides.

The disadvantage of the known housing parts with metal fixing material feedthroughs with pressure glazing or adapted feedthroughs is their high manufacturing effort and the risk of errors in the orientation of the components, especially with very small or thin housing parts.

It is therefore an object of the invention to provide an improved housing part having an electrical feedthrough which overcomes these disadvantages.

disclosure of the invention

The object is achieved by a housing part with the features of claim 1. Within the scope of the invention, a housing part with better symmetry is provided, which reduces the manufacturing effort for the housing part because less effort has to be invested in the correct alignment of the components. In addition, the risk of components being incorrectly arranged in the finished housing part is reduced.

According to a first embodiment of the invention, the improved symmetry of the housing part is due to a symmetrical implementation. In a second embodiment of the invention, the improved symmetry of the housing part is achieved by a symmetrical connecting flange on the outer edge of the base body. It is particularly advantageous in one embodiment if the housing part combines both variants, i.e. it has both a symmetrical feedthrough and a symmetrical connecting flange.

Overall, a housing part is proposed, in particular for an electrical storage device, with an electrical feedthrough. The housing part comprises a base body with a through-opening and a connection pin arranged in the through-opening, which is held in the through-opening in an electrically insulating manner via a fixing material, so that an electrical feedthrough is formed.

According to the invention, a disk-shaped base body with a substantially uniform thickness is used as the base body. Substantially uniform thickness means that the base body has the same thickness outside the area of the through-opening as in an area adjacent to the through-opening. The base body is therefore flat and has no reinforcement, collar, flexible flange or similar reinforcing means. When considering the thickness, the edge on the outer circumference of the base body is not taken into account. With such a housing part, thin, compact housings with a lot of volume inside the housing can be provided. In addition, complex forming work on the base body is eliminated.

In the first embodiment according to the invention, the base body has a symmetrical feedthrough. The fixing material and the connection pin are arranged symmetrically to a plane of symmetry lying centrally in the plane of the base body, so that the housing part is symmetrical with respect to the feedthrough. In terms of geometry, there are therefore no differences between the top and bottom of the housing part. This means that one end face or surface of the connection pin is just as far away from the plane of symmetry on the bottom of the housing part as the other end face or surface of the connection pin on the top of the housing part.

The same applies to the fixing material. Such a symmetrical housing part can be manufactured with less manufacturing effort, since measures for determining the orientation of the individual parts can be omitted. The distance between the end faces of the connecting pin is the thickness of the connecting pin.

It is also provided that the height of the fixing material is greater than the thickness of the base body in the area of the through opening. The end faces of the fixing material are thus each arranged to protrude beyond a surface of the base body. The fixing material advantageously has a substantially uniform height starting from the connection pin, i.e. a substantially constant height. In other words, the opposite end faces of the fixing material - starting from the connection pin - are advantageously arranged substantially parallel to one another. An exception to this can be a contact area between the base body and the fixing material (see below). This design and arrangement of the fixing material provides a particularly compact, space-saving feedthrough, in contrast to a feedthrough with an arcuately curved course of the fixing material surface as the height of the fixing material increases towards the connection pin. Such dimensioning of the fixing material also offers manufacturing advantages, as it is ensured that there is enough fixing material for a secure and tight fixation, in particular glazing, of the connection pin. In other words, the fact that the front sides of the fixing material are each arranged to protrude beyond a surface of the base body creates a reservoir for the fixing material, which can be used to compensate for volume fluctuations in the fixing material and fluctuations in the dimensions of the components, for example. This also improves the insulation between the connection pin and the base body, so that a short circuit with the base body can be avoided when the connection pin is contacted.

Towards the contact area between the fixing material and the base body, both end faces of the fixing material converge towards the base body. In other words the height of the fixing material increases from the base body towards the connection pin until the essentially uniform height is reached or the front sides of the fixing material run parallel to each other. The contact area can coincide with the wall of the through hole, but it does not have to (see description below for "fixing material overflow ¹ ").

In the context of the disclosure, terms such as “uniform thickness”, “uniform height”, “constant height”, “parallel end faces” etc. are of course to be understood within the scope of the usual manufacturing tolerances.

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 is a maximum of 30%, preferably a maximum of 28%. An advantageous lower limit for the difference can be 6% or 8%, i.e. the height of the fixing material is 6 to 30% greater than the thickness of the base body. In a symmetrical implementation, the difference is distributed symmetrically on both sides of the housing part, so that it is a maximum of 15% or a maximum of 14% and/or at least 3% or 4% per side.

The term "symmetrical feedthrough" is of course to be understood within the limits of the usual manufacturing tolerances. In the context of the disclosure, it is considered to be symmetrical in particular if a plane of symmetry lying centrally in the plane of the base body deviates preferably by less than 4% of the thickness of the connecting pin from a connecting pin plane of symmetry lying centrally in the plane of the connecting pin. In particular, the distance between the planes of symmetry is less than 4% of the thickness of the connecting pin. Advantageously, the deviation can be even smaller, in particular less than 3%, preferably less than 2%.

In the second embodiment according to the invention, the housing part comprises a symmetrical base body. For this purpose, the disc-shaped base body with a substantially uniform thickness on its outer edge, has a symmetrical connecting flange. The symmetrical connecting flange is arranged symmetrically to a plane of symmetry lying centrally in the plane of the base body. The term "symmetrical connecting flange" is of course to be understood within the limits of the usual manufacturing tolerances. A symmetrical connecting flange is preferably designed in that the base body has a matching step and/or bevel or chamfer on the edge on both its top and bottom sides, ie there is a step and/or chamfer on both sides. Because the base body has a symmetrical connecting flange, which can also be designed without steps and without bevels, no distinction has to be made between the top and bottom of the base body during manufacture of the housing part. Even if the finished housing part is later to have an asymmetrical leadthrough, in which the front side of the connection pin and/or the fixing material on the underside of the housing part is at a different distance from the plane of symmetry of the base body than that on the top of the housing part, the correct orientation of the base body in relation to the later top or bottom side is not important during the manufacture of the housing part. This reduces the manufacturing effort. The connection to another housing component - for example a cup-shaped housing element or another cover element of the cover - can be made at the symmetrical connecting flange, for example using a welded or soldered connection. The connection is preferably designed in such a way that it is largely gas-tight and preferably provides a He leak rate of less than 10' ⁸ mbar l/sec at a pressure difference of 1 bar. In addition, the symmetrical connecting flange can have a centner function.

In order to improve the insulation between the connection pin and the base body and to provide sufficient fixing material, it can also be advantageous for a base body with a symmetrical connecting flange if the height of the fixing material is greater than the thickness of the base body in the area of the Through opening. At least one plane or end face of the fixing material can be arranged to protrude beyond a surface of the base body. The fixing material advantageously has a substantially uniform height starting from the connecting pin, i.e. a substantially constant height. In other words, the opposing end faces of the fixing material - starting from the connecting pin - are advantageously arranged substantially parallel to one another. An exception to this can be a contact area between the base body and the fixing material (see below). This design and arrangement of the fixing material provides a particularly compact, space-saving feedthrough, in contrast to a feedthrough with an arcuately curved course of the fixing material surface as the height of the fixing material increases towards the connecting pin. Such dimensioning of the fixing material also offers manufacturing advantages, as it is ensured that there is sufficient fixing material for secure and tight fixing, in particular glazing, of the connecting pin. In other words, the fact that at least one end face of the fixing material is arranged so as to protrude beyond a surface of the base body provides a reservoir for the fixing material, which can be used to compensate for volume fluctuations in the fixing material and fluctuations in the dimensions of the components. This also improves the insulation between the connection pin and the base body, so that a short circuit with the base body can be avoided when the connection pin is contacted.

Towards the contact area between the fixing material and the base body, at least one end face of the fixing material converges towards the base body. In other words, the height of the fixing material increases from the base body towards the connection pin until the essentially uniform height is reached or the end faces of the fixing material run parallel to each other. The contact area can coincide with the wall of the through hole, but it does not have to (see below). In the context of the disclosure, terms such as “uniform thickness”, “uniform height”, “constant height”, “parallel end faces”, “consistent step and/or bevel” etc. are of course to be understood within the scope of the usual manufacturing tolerances.

Here too, 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 is a maximum of 30%, preferably a maximum of 28%. An advantageous lower limit for the difference can be 6% or 8%, i.e. the height of the fixing material is 6 to 30% greater than the thickness of the base body. The difference can be distributed symmetrically on both sides of the housing part, so that it is a maximum of 15% or a maximum of 14% and/or at least 3% or 4% per side. In the case of a base body with a symmetrical connecting flange, the difference can also be distributed asymmetrically between the sides of the housing part. A flush arrangement of the fixing material and the base body on one side is also possible.

A particularly advantageous embodiment of the housing part is one in which the base body has both a symmetrical passage and a symmetrical connecting flange. Such housing parts can be manufactured with reduced effort. In addition, the effort involved in assembling a housing that includes the advantageous symmetrical housing part is simplified because the top and bottom of the housing part have a matching geometry.

Within the scope of the disclosure, the fixing material advantageously has a shaped surface in the region in which its end faces run essentially parallel or the fixing material has an essentially uniform height. A shaped surface is formed in particular in contact with melt molds and preferably has a surface roughness Ra (arithmetic mean roughness) of > 1 pm. In the transition to the base body, ie in the contact region in which at least one surface of the fixing material faces the base body converges, the fixing material can have a free-form surface, preferably with a curvature. A free-form surface forms without contact with a mold. The free-form, preferably curved section can have a fire-polished surface, preferably with a surface roughness Ra of < 0.2 pm, preferably < 0.1 pm. The surface roughness Ra was determined here tactilely using a profilometer. Ra is preferably determined in accordance with DIN EN ISO 4287.

When looking at the housing part in vertical cross-section, the base body has a gap on both sides between the connecting pin arranged in its through-opening, which gap is filled with fixing material. The gap is therefore the distance between the wall of the through-opening and the wall of the connecting pin.

In the first embodiment according to the invention, the second embodiment according to the invention or a combination of both embodiments according to the invention, it is advantageous if an imaginary tangent applied to the surface of the fixing material at the contact point with the connection pin forms a contact angle with the connection pin of approximately 90°. In other words, there is a right angle (naturally within the limits of the usual manufacturing tolerances), here preferably an angle of 90° with a deviation of +/- 2°. This is described in more detail below. This provides a hermetic connection and at the same time a compact feedthrough.

In the first embodiment according to the invention, the second embodiment according to the invention or a combination of both embodiments according to the invention, it can be advantageous if the desired substantially uniform height of the fixing material is present at the latest after 25%, preferably at the latest after 20%, preferably at the latest after 15% of the distance between the base body and the connecting pin, wherein the reference point, ie the starting point for the observation, the base body. A plateau is thus quickly formed in which the fixing material has a substantially constant height and the end faces of the fixing material run substantially parallel to one another. A plateau with a substantially constant height of the fixing material can advantageously extend over at least 75%, advantageously at least 80%, preferably at least 85% of the distance between the base body and the connection pin. This provides a long insulation distance.

In the first embodiment according to the invention, the second embodiment according to the invention or a combination of both embodiments according to the invention, it can be advantageous if the fixing material not only protrudes beyond one or both surfaces of the base body, but also covers the edge of the through-opening, i.e. the fixing material can cover an area of the top side of the base body adjacent to the through-opening. Such a constellation is referred to in the disclosure as "fixing material overflow" or "fixing material coverage". A fixing material overflow can be formed on one side of the base body or on the other side of the base body or on both sides of the base body, depending on whether a symmetrical or asymmetrical passage is present. In a design with fixing material overflow, the contact area between the fixing material and the base bodies is not only in the area of the wall of the through-opening, but extends beyond the edge of the through-opening onto a surface of the base body, on at least one side of the base body. Here too, at least one end face of the fixing material converges towards the base body. In other words, the height of the fixing material increases starting from the base body, but not only starting from the through-opening, but already starting from a surface of the base body, so that one edge of the through-opening is covered.

A fixative overflow increases the reservoir for the fixative and increases the isolation effect. In addition, the implementation mechanically more stable and the hermetic seal more secure. In this variant too, it can be advantageous if, with regard to the desired essentially uniform height of the fixing material, starting from the first contact of the fixing material with the base body surface, a plateau quickly forms in which the end faces of the fixing material run essentially parallel to one another and the fixing material has an essentially constant height. The desired essentially uniform height of the fixing material is advantageously achieved after 10% at the latest, preferably after 5% at the latest, of the distance between the base body and the connection pin. A plateau with an essentially constant height can advantageously extend over at least 90%, advantageously at least 100% of the distance between the base body and the connection pin.

In the embodiments of the invention, the connecting pin can have two end faces and a lateral surface. For example, it can have a circular cylindrical shape, with the lateral surfaces of the cylinder facing the fixing material. 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. In the embodiment with a symmetrical leadthrough, the connecting pin is also constructed symmetrically. In the embodiment with a symmetrical connecting flange, it can be constructed symmetrically or asymmetrically.

Within the scope of the embodiments of the invention, the disk-shaped base body, the fixing material and the connecting pin form a metal fixing material passage through which the through opening of the base body is closed. The passage formed is preferably hermetically sealed. Hermetically sealed is considered to be a He leakage rate of 1 ■ 10 ^-8 mbar l/s at a pressure difference of 1 bar. The housing part according to the invention can in particular be a housing part for forming a housing for an electrical storage device. For example, the housing part can be designed as a cover part or lid that can be joined together with a cup-shaped housing element to form a housing for an electrical storage device. However, the housing part can also be part of a lid or cover part in that the housing part is inserted into an opening that is formed in a cover element. The electrical storage device can in particular be a battery or a capacitor, including a supercapacitor, wherein the housing usually accommodates at least one storage cell that can be electrically contacted from the outside via the electrical feedthrough as a connection terminal. The housing part can also comprise a feedthrough that is designed as a multi-pole feedthrough, in which the base body has several through-openings and in each of the through-openings a connection pin is held by a fixing material.

In an advantageous embodiment, the base body has a thickness in the range 0.1 mm to 1 mm, preferably 0.15 mm to 0.8 mm, in particular 0.15 mm to 0.6 mm. As a result, a housing part for a particularly compact, small electrical device - in particular an electrical storage device or sensor housing, preferably a battery, in particular a microbattery, or capacitor - can be provided with a feedthrough.

In the case of a housing part with a symmetrical leadthrough, it can be advantageous if the base body or the housing part has a connecting flange, in particular an asymmetrical connecting flange, on the outer edge. The connecting flange can serve to align and center the housing part or base body in relation to another housing component, for example a cup-shaped housing element or a cover element, during the assembly of a housing or cover. A corresponding counter flange can advantageously be formed on the other housing component. In addition, the connection to the other housing component can be made on the connecting flange, for example by means of a welded connection or soldered connection. The connection is preferably designed in such a way that it is largely gas-tight and preferably a He leak rate of less than 10' ⁸ mbar l/sec at a pressure difference of 1 bar is provided.

In an advantageous further development of the design with symmetrical implementation, the connecting flange can be designed as a one-sided step or one-sided bevel, with the thickness of the base body decreasing towards the edge. This results in an asymmetrical connecting flange. The step or bevel of the connecting flange can be formed on the first side of the base body, with the first side being the side that faces inwards when a housing is formed. Alternatively, the step or bevel could also be formed on the second side of the base body, with the second side being the side that faces outwards when a housing is formed.

Due to the low material thickness of the base bodies of housing parts, especially for small electrical devices, such as micro batteries, and the fact that the connecting flange has an even lower thickness, a small one-sided step or bevel on the connecting flange is usually difficult to identify and thus the orientation of the base body can often only be determined with great equipment effort.

However, because the fixing material and the connecting pin are arranged symmetrically to a plane of symmetry in the middle of the plane of the base body within the scope of the invention, it is irrelevant for the manufacture of the housing part from individual parts in which direction the connecting flange points, ie on which side of the base body the one-sided step or the one-sided bevel is formed. Due to the orientation of the base body, of the fixing material and the connecting pin on the plane of symmetry, the prior orientation of the base body in relation to the step or bevel can be omitted during the manufacture of the housing part. This saves costs and avoids product defects.

In an advantageous further development of the design with symmetrical feedthrough or the design with symmetrical connecting flange or a design that includes both, the front sides of the connection pin are each arranged flush with a surface or front side of the fixing material. The surfaces of the connection pin are thus on both sides of the housing part in the same plane as the surface of the fixing material. Due to the flat shape of the electrical feedthrough, the feedthrough and thus the housing part can have a low overall height.

In an advantageous development of the design with symmetrical feedthrough or the design with symmetrical connecting flange or a design that includes both, both end faces of the connection pin are arranged so as to protrude beyond a surface or end face of the fixing material, particularly in the case of symmetrical feedthrough at the same distance from the plane of symmetry of the base body. The end faces or surfaces of the connection pin are thus located on both sides of the housing part above the level of the respective end face or surface of the fixing material. This creates an increased contact surface, which allows simple electrical contact of the connection pin, for example by welding on contact lugs.

When designing with a symmetrical base body by means of a symmetrical connecting flange, it can be advantageous if the connecting pin is designed asymmetrically, ie has an asymmetrical geometry and/or an asymmetrical structure. Alternatively or additionally, the connecting pin and/or the fixing material can advantageously be designed asymmetrically in the The feedthrough can be arranged in such a way that its front sides are spaced at different distances from the plane of symmetry of the base body. Measures for the orientation of an asymmetrical connection pin or an asymmetrically arranged connection pin can be omitted.

In a design with a symmetrical base body through a symmetrical connecting flange, it can be advantageous if one end face or both end faces of the connection pin are arranged flush with a surface of the base body. Since the base body is symmetrical, the manufacturing effort for the housing part is also reduced if only one end face of the connection pin is arranged flush with a surface of the base body or the end faces of the connection pin are at different distances from the plane of symmetry of the base body, i.e. there is an asymmetrical feedthrough.

In a design with a symmetrical base body through a symmetrical connecting flange, it can be advantageous if one end face or both end faces of the connection pin are arranged to protrude beyond a surface of the base body. Since the base body is symmetrical, the manufacturing effort for the housing part is also reduced if only one end face of the connection pin is arranged to protrude beyond a surface of the base body or if the end faces of the connection pin are at different distances from the plane of symmetry of the base body, i.e. an asymmetrical feedthrough is present.

The material of the base body and/or the material of the connecting pin are preferably selected from steel, in particular ferritic, austenitic or duplex steel, stainless steel, stainless steel, iron-nickel alloys, iron-nickel-cobalt alloys, KOVAR, molybdenum, titanium, titanium alloy, aluminum or aluminum alloy. The connecting pin can consist of or comprise one of the materials mentioned. A preferred example comprises a base body made of austenitic steel and a connecting pin comprising or consisting of austenitic steel.

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

Preferred glasses include technical glasses, in particular oxidic glasses, which are preferably chemically resistant to common materials in connection with electrical energy storage devices. In the case of a technical glass, the fixing material is, for example, an aluminum borate glass, which comprises Al2O3 and B2O3, or a bismuth glass, which comprises, for example, Bi2O3 as a glass former. Alternatively, glasses that comprise lead oxide as a glass former, in particular glasses from the PbO-B2O3 system, or glasses containing vanadium can be used as fixing material.

For glass-metal bushings, suitable glasses are selected as fixing materials according to their properties such as melting temperature and/or expansion coefficient.

Preferably, the melting point of the fixing material is selected to be lower than the melting point of the material of the connecting pin or of all materials of the connecting pin. This ensures that the connecting pin is not damaged when the metal fixing material is manufactured using a temperature treatment step, for example for sintering or glazing the fixing material.

In such a temperature treatment step, the fixing material can be obtained from a compact, ie a fixing material precursor, which may be, for example, a glass powder or a glass ceramic powder or a ceramic powder The glass powder can consist of or comprise a partially crystallizable glass, so that during a temperature treatment the partially crystallizable glass is ceramized and a glass ceramic is obtained.

Glasses with a low melting temperature can be advantageous. In a variant described below, a glass whose melting temperature is below the melting point of aluminum or an aluminum alloy is 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 a bismuth-based glass that includes Bi2O3 as a glass former, or a lead-based glass that includes PbO as a glass former.

For example, an aluminum borate glass with the main components AI2O3, B2O3, BaO and SiO2 is used as a glass or glass ceramic material. The expansion coefficient of such a glass material is preferably in the range 9.0 to 9.5 ppm/K or 9.0 to 9.5 10' ⁶ /K. If, for example, a bismuth glass is used, the expansion coefficient is approximately 10.5- 10 ^-6 /K.

However, depending on the thermal expansion behavior of the materials of the base body and connection pin, other glasses with a different thermal expansion coefficient can also be used advantageously.

In order to achieve a particularly good seal between the metal parts, i.e. the base body and the connection pin, and the fixing material, the electrical feedthrough can be designed in the form of a pressure glazing. In this case, a thermal expansion coefficient of the base body is selected to be greater than a thermal expansion coefficient of the fixing material, so that after a temperature treatment in which the fixing material is glazed in the through hole, the base body contracts more strongly than the fixing material. This permanently absorbs pressure forces through the base body. exerted on the fixing material. These pre-tension the fixing material and ensure a particularly durable seal.

Accordingly, it is preferred that a thermal expansion coefficient of the base body is greater than a thermal expansion coefficient of the fixing material. 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 most preferably at least 50% greater than the thermal expansion coefficient of the fixing material.

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

In an advantageous embodiment, the expansion coefficient of the base body is in the range 12-10' ⁶ 1/K to 19-10' ⁶ 1/ K and the expansion coefficient of the fixing material is in the range 9 10' ⁶ 1/K to 11 -10' ⁶ 1/K.

The 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.

In an advantageous embodiment, the expansion coefficient of the connecting pin is in the range 6 10' ⁶ 1/K to 11 ■ 10' ⁶ 1/K. Accordingly, the expansion coefficient of the connecting pin or a core of the connecting pin is preferably adapted to the expansion coefficient of the fixing material when the implementation is carried out as a pressure glazing or is selected to be slightly smaller. For pressure glazing, for example, an austenitic steel with an expansion coefficient of approx. 16 -10' ⁶ 1/ K can be combined with a bismuth-based glass with an expansion coefficient of approx. 10.5 -10' ⁶ 1/ K and a core made of ferritic steel with an expansion coefficient of approx. 10 ' ⁶ 1/ K.

As an alternative to pressure glazing, the expansion coefficient of the base body and the expansion coefficient of the fixing material can be adapted to each other. It is preferred if the difference in the expansion coefficients is less than 5%.

In particular, an adapted implementation is understood to mean that the expansion coefficients differ essentially by at most 1 * 10 ' ⁶ 1/K, in particular are essentially the same. The expansion coefficient of the connection pin is preferably adapted in the same way to the expansion coefficient of the fixing material.

Where values for the coefficient of expansion have been mentioned above in connection with pressure glazing or adapted glazing for materials, these refer to the linear thermal expansion coefficient a usually specified in connection with glass-metal penetrations in the temperature interval 20-300°C.

In an advantageous embodiment, it is provided that the connection pin has a core made of a first electrically conductive material and that at least on a first side of the electrical feedthrough a first end face of the core is covered with a covering material made of a second electrically conductive material, wherein advantageously the connection pin and the fixing material are designed and arranged in such a way that the first electrically conductive material of the core is inaccessible on the first side of the electrical feedthrough. For this purpose, the fixing material directly adjoins the covering material.

It is advantageous if the first side of the electrical feedthrough, on which the first electrically conductive material of the core is advantageously inaccessible, is the side which faces inwards when a housing is formed. The first end face of the core with covering material thus faces inwards when a housing is formed. An alternative arrangement in which the first electrically conductive material of the core is inaccessible from the side which faces outwards when a housing is formed is of course also possible and also advantageous.

If the housing part has an asymmetrical connecting flange, it is advantageous if the electrical feedthrough is symmetrical in that both end faces of the core are covered with the covering material made of the second electrically conductive material.

The proposed connection pin comprises at least two different materials, wherein the first electrically conductive material of the core is preferably selected according to the requirements of the metal fixing material implementation.

For this purpose, the first electrically conductive material can be selected in particular with regard to the thermal expansion coefficient and the resistance to deformation. The second electrically conductive material is preferably selected according to the requirements of the electrical storage device. In particular, the second electrically conductive material can be selected with regard to chemical resistance to materials of the storage cell and electrochemical potentials.

The connecting pin can, for example, have a circular cylindrical shape, with the lateral surfaces of the cylinder facing the fixing material and at least one the end faces of the core are covered with the covering material. In addition to the circular cylinder shape, general cylinder shapes with other end face shapes are also conceivable. For example, oval shapes or rectangles with rounded corners are conceivable.

In addition to covering a first end face of the core with the covering material, it can also be provided to 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 or different to the second electrically conductive material. If different materials are selected, the second electrically conductive material in particular can be adapted to the requirements of the materials of a storage cell and the third electrically conductive material can be optimized, for example, for simple, secure connection to electrical connections. Welding properties or soldering properties can be used as a criterion for the material selection, for example.

In an advantageous variant, a lateral surface of the core facing the fixing material is at least partially not covered with covering material and is directly adjacent to the fixing material. Preferably, the lateral surface of the core is completely free of the covering material. In another advantageous variant, 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.

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 when the metal fixing material is manufactured using a temperature treatment step, for example for sintering or glazing the fixing material. 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 small thicknesses of the covering material are applied, electroplating, coating and vapor deposition are preferred. Conversely, plating, welding and soldering are preferred if comparatively high thicknesses of the covering material are applied.

During plating, the starting materials, such as the covering material and the core material, are usually provided in the form of plates or strips and placed on top of each other and joined together by rolling. During soldering or welding, for example, the covering material in the form of a sheet or foil can be placed on the core material and welded or soldered to it.

Examples of possible vapor deposition processes include physical vapor deposition (PVD) such as sputtering, chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD).

Regardless of the type of application, the covering material is preferably arranged free of openings or defects so that the corresponding end face of the core is completely covered. In particular, this is intended to prevent the first conductive material from coming into contact with materials from the interior of an energy storage device.

Furthermore, the covering material is preferably selected and arranged in such a way that it is suitable for soldering or welding electrical contacts such as contact lugs. Accordingly, the covering material Preferably designed in such a way that it is suitable for soldering or welding electrical contacts and no cracks or openings are created in the covering material.

Preferably, the metallic materials that can come into contact with an electrolyte 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 have a high chemical resistance to non-aqueous battery electrolytes, in particular to carbonates, preferably carbonate mixtures with a conductive salt, preferably comprising LiPFe.

The first electrically conductive material of the core of the connection pin is preferably selected from steel, in particular ferritic, austenitic or duplex steel, stainless steel, stainless steel, iron-nickel alloys, iron-nickel-cobalt alloys, KOVAR, molybdenum, titanium, titanium alloy, aluminum or aluminum alloy.

The second electrically conductive material and/or the third electrically conductive material of the connection pin is preferably selected from aluminum, an aluminum alloy, AlSiC, copper, a copper alloy, molybdenum, nickel or nickel alloys, palladium, silver or gold.

A preferred example of a terminal pin has a core made of a stainless steel, in particular a ferritic stainless steel, and a cover material made of aluminum or an aluminum alloy.

However, other material combinations in which a melting point of the second electrically conductive material and/or the third electrically conductive material is lower than a melting point of the first electrically conductive material of the core of the connection pin are also preferred. Usually, a safety valve and/or a predetermined breaking point is provided on housings for an energy storage device as a safety element in order to reduce the pressure in a controlled manner in the event of excess pressure inside. The housing part preferably has such a safety element. For this purpose, it is preferable to select a pressing force for the connection pin held by the fixing material so that the connection pin is pressed out when a predetermined pressing force is exceeded. Such an adjustment of the pressing force is known, for example, from DE 202020106 518 U1.

Preferably, the fixing material and its connection to the wall of the through-opening 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 set by one or more of the following measures: a. selecting the thickness of the glazing, b. selecting the fixing material, c. selecting the proportion of bubbles in the fixing material, d. structuring the surface of the fixing material by adjusting the shape of a fixing material molded body before glazing, e. structuring the surface of the fixing material during glazing, f. laser processing the surface of the fixing material after glazing, g. introducing notches or tapers into the fixing material on one or both sides and/or h. introducing notches or tapers into the connecting pin and/or the base body.

The housing part can advantageously be used in an electrical device, in particular an electrical storage device, preferably a microbattery, or e.g. in a sensor housing. A housing part according to the invention with an electrical feedthrough is produced within the scope of the invention by providing a disk-shaped base body with a substantially uniform thickness and a through-opening, a fixing material precursor and a connection pin. At least the base body, preferably also the fixing material and the connection pin, are provided in a random orientation. The fixing material or a precursor material can be provided in the form of a molded body. The volume of the fixing material precursor is advantageously dimensioned such that in the housing part produced, the fixing material protrudes beyond a surface of the base body on at least one side. The molded body can, for example, have the shape of a hollow cylinder. To form the electrical feedthrough, the connection pin in the molded body of the fixing material is arranged in the through-opening of the base body. The base body, the fixing material molded body, which is preferably in the form of a hollow cylinder, and the connection pin are positioned according to the desired symmetry of the housing part using suitable melt molds. In the case of a symmetrical feedthrough, the base body, the fixing material molded body and the connecting pin are positioned symmetrically to a plane of symmetry lying centrally in the plane of the base body, whereby it is irrelevant in which direction any asymmetrical connecting flange of the base body points. If the base body has a symmetrical connecting flange, the base body, fixing material and connecting pin can also be positioned using appropriate melting molds in such a way that - if desired - an asymmetrical feedthrough is created in which the front sides of the fixing material and/or connecting pin on the first side of the housing part have a different distance to the plane of symmetry lying centrally in the plane of the base body than on the second side of the housing part and/or in which the connecting pin is designed asymmetrically. The melting molds are designed and arranged in such a way and the volume of the fixing material molded body is selected in such a way that in the area of the through opening in the finished component the height of the fixing material is greater than the thickness of the base body, and preferably the end faces of the fixing material run essentially parallel starting from the connection pin. The connection pin is then glazed into the opening by means of a temperature treatment (heating), the fixing material forming an intimate bond with the material of the connection pin and the material of the base body. Except for the contact area between the base body and the fixing material, the surface of the fixing material is advantageously formed in contact with the melt molds. This is therefore a shaped surface with a typical roughness that was described above in connection with the housing part. In the transition to the base body, i.e. in the contact area, the surface of the fixing material can form freely and - in an advantageous variant - even extend over the edge of the through-opening. To avoid repetition, reference is made to the above explanations.

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 a housing part described herein with at least one electrical feedthrough. Furthermore, the electrical storage device preferably comprises at least one storage cell, in particular a battery cell or a capacitor cell, which is arranged, for example, in a cup-shaped housing element.

The storage device according to the invention is designed to be compact, so that as much active volume as possible is made available inside the housing, whereby the battery and/or the capacitor can have the highest possible capacity.

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

In an advantageous variant of an electrical storage device, the material thickness or thickness of the base body is in the range 0.1 mm to 1 mm, preferably 0.15 mm to 0.8 mm, in particular 0.15 mm to 0.6 mm.

Particularly compact electrical storage devices are provided if the electrical storage device has a total construction height of at most 40 mm, preferably at most 30 mm or at most 20 mm or at most 10 mm and/or the total construction height is advantageously in the range 1 mm to 40 mm.

The diameter, especially of a micro battery, can be 3 mm to 30 mm or 4 mm to 20 mm or 6 mm to 16 mm.

In an advantageous embodiment, the electrical storage device is a microbattery. Basically, there are different types of microbatteries, e.g. pin-shaped microbatteries, in which a small diameter of a few mm is compensated by a relatively large overall height (up to approx. 40 mm), and button-shaped microbatteries, which have a relatively large diameter but a small overall height. In the latter case, the overall height can be in the range of 1 to 5 mm. The height is advantageously at most 5 mm, advantageously at most 4 mm, preferably at most 3 mm. The invention will be described in more detail below with reference to the schematic figures and without limitation thereto.

They show:

Fig. 1 : a known housing part with an asymmetrical electrical feedthrough with reinforced base body in the area of the through opening,

Fig. 2: another known housing part with an asymmetrical electrical feedthrough with a base body with a flexible flange,

Fig. 3: a housing part with electrical feedthrough (comparative example),

Fig. 4: a first embodiment of the invention with a symmetrical implementation,

Fig. 5: a second embodiment of the invention with a symmetrical bushing and an asymmetrical connecting flange,

Fig. 6: a third embodiment of the invention with a symmetrical bushing and an asymmetrical connecting flange,

Fig. 7: a fourth embodiment of the invention with a symmetrical connecting flange and asymmetrical bushing,

Fig. 8: a fifth embodiment of the invention with a symmetrical connecting flange and asymmetrical bushing,

Fig. 9: a sixth embodiment of the invention with a symmetrical connecting flange and a symmetrical bushing, Fig. 10: a seventh embodiment of the invention with a symmetrical feedthrough and completely coated core of the connection pin,

Fig. 11: an eighth embodiment of the invention with a symmetrical feedthrough and double-sided covering of a core of the connection pin,

Fig. 12: a ninth embodiment of the invention with a symmetrical connecting flange, an asymmetrical feedthrough and one-sided covering of the core of the connection pin,

Fig. 13: a tenth embodiment of the invention with a symmetrical connecting flange, a symmetrical leadthrough and double-sided covering of the core of the connecting pin with flush design and

Fig. 14: a section of a schematic detailed representation.

Figure 1 shows a housing part 10 known in the prior art with an electrical feedthrough. The housing part 10 comprises a base body 12 with a through-opening 14 into which a connection pin 20 is inserted. The connection pin 20 is held in the through-opening 14 in an electrically insulating manner by means of a fixing material 16. In order to provide mechanical stability and tightness of the feedthrough despite the low material thickness of the base body 12, the base body 12 has a reinforcement area with a width W which borders on the through-opening 14 and within which the base body 12 has an increased thickness d2. Outside the reinforcement area, the base body 12 has the smaller thickness di. On its outer edge 17, a connecting flange for connecting to another housing component is formed on the base body 12. The connecting flange is designed here as an example as a one-sided step, i.e. there is an asymmetrical connecting flange 18a. Figure 2 shows another housing part 10 known from the prior art with an electrical feedthrough, which, as described above, has a base body 12 with a through-opening 14 in which a connection pin 20 is held in an insulating manner via a fixing material 16. The base body 12 additionally comprises a flexible flange 30, which 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 which is greater than the thickness di 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, so that a glazing length can be set independently of other dimensions of the base body 12 or a housing with the base body. Even in the case of a housing part 10 with a flexible flange 30, an asymmetrical connecting flange 18a can be provided on the outer edge 17 of the base body 12 for connecting to another housing component.

In Figures 1 and 2 it can be seen that the geometric design of the top of the housing part 10 differs from the geometric design of the bottom of the housing part 10 due to areas of the base body 12 protruding from a housing part plane - such as reinforcement with thickness d2 and/or a flexible flange 30. - In general, within the scope of the disclosure of the prior art, the embodiments according to the invention and the comparative example, the terms top, ie the side of the housing part pointing upwards in the figure, and bottom, ie the side of the housing part pointing downwards in the figure, are used solely to illustrate the description of the figures without reference to the - whether the corresponding side is later arranged in an electrical device facing the interior of the housing or faces outwards. - With the help of areas that protrude from the housing part plane, in particular parts of the base body 12, it is easy to identify the top and bottom of the base body 12 or housing part 10. This enables the individual housing parts to be reliably aligned for the production of the electrical feedthrough and/or the later alignment of the housing part 10 for the assembly of a housing or cover.

However, Figures 1 and 2 also show the disadvantage of such known housing parts 10, namely that the protruding areas form space requirements that must be structurally accommodated inside the housing or outside the electrical device.

Figure 4 shows a first embodiment of a thin, compact housing part 10 according to the invention with a symmetrical electrical feedthrough. The housing part 10 comprises a base body 12 with a through-opening 14 into which a connection pin 20 is inserted. The connection pin 20, which here has two end faces 21 and a lateral surface, is held in the through-opening 14 in an electrically insulating manner by means of a fixing material 16. The fixing material 16 seals both against an inner wall of the through-opening 14 and against the connection pin 20, so that the through-opening 14 is tightly closed by the fixing material 16 and a metal fixing material feedthrough is formed.

The housing part 10 shown is particularly suitable for use in connection with electrical storage devices such as batteries, in particular micro batteries, and capacitors. Accordingly, the housing part 10 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 forms then, for example, a connection terminal of the electrical storage device. To form a housing or cover for the electrical storage device, the housing part 10 with electrical feedthrough is joined to other housing components. If the housing part 10 is designed as a cover part, a housing for an electrical storage device can be formed by joining the cover part to a cup-shaped housing element. Alternatively, the housing part can be inserted into an opening provided in a cover element and thus be part of a cover. A cover constructed in this way comprises at least one further housing component in addition to the housing part 10 according to the invention in the form of the cover element with opening.

Usually, 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 connection of such a storage cell can be electrically connected to the connection pin 20 and another connection to another housing part. It is of course also possible to form several through-openings 14 in a housing part 10 or base body 12 and to arrange several connection pins 20 so that a multi-pole feedthrough is provided.

As can be seen, a disk-shaped base body 12 with a substantially uniform thickness D is used within the scope of the invention. Substantially uniform thickness means that the base body 12 has the same thickness outside the area of the through-opening 14 as in an area adjacent to the through-opening 14. The base body 12 is thus flat and has no reinforcing means produced by forming processes, such as reinforcement, collar, flexible flange or the like. With such a housing part 10, thin, compact housings with a lot of volume inside the housing can be provided. In addition, the base body 12 has a symmetrical feedthrough. The fixing material 16 and the connecting pin 20 are arranged symmetrically to a plane of symmetry S located centrally in the plane of the base body, so that the housing part 10 is symmetrical with respect to the feedthrough. In terms of geometry, there are therefore no differences between the top and bottom of the housing part 10. This means that the front side 21 or surface of the connecting pin 20 is just as far away from the plane of symmetry S on the bottom of the housing part 10 as the front side 21 is on the top of the housing part 10. The same applies to the fixing material 16. A housing part 10 that is symmetrical in this way can be manufactured with less production effort, since measures for determining the orientation of the individual parts before placing them in melting molds can be omitted.

It is also provided that the height H of the fixing material is greater than the thickness D of the base body in the area of the through opening 14. The difference between height H and thickness D is divided symmetrically between the sides of the housing part 10. The end faces of the fixing material 16 are thus each arranged to protrude beyond a surface of the disk-shaped base body 12. As can be seen, the opposite end faces of the fixing material 16 starting from the connection pin 20 are arranged essentially parallel to one another - except for the contact area between the base body 12 and the fixing material 16. In other words, the fixing material 16 starting from the connection pin 20 - except for the contact area between the base body 12 and the fixing material 16 - has an essentially uniform height. Towards the contact area between the fixing material and the base body, both end faces of the fixing material 16 converge towards the base body 12. In other words, the height of the fixing material 16 increases starting from the base body 12. The contact area between the fixing material and the base body coincides here with the wall of the through-opening 14, ie it lies in the area of the wall of the through-opening. Such dimensioning of the fixing material also offers manufacturing advantages, as it ensures that there is sufficient fixing material 16 for secure fixing, in particular glazing, of the connecting pin 20 and that no undesirable menisci or even holes occur in the contact between fixing material 16 and connecting pin 20 and/or holes between fixing material 16 and base body 12. In addition, the height H of the fixing material 16 improves the insulation between the connecting pin 20 and base body 12, so that a short circuit with the base body 10 can be avoided when contacting the connecting pin 20.

In the first embodiment of the housing part 10 shown in Figure 4, both end faces 21 of the connection pin 20 are flush with the corresponding surfaces or end faces of the fixing material 14.

With regard to the materials of the components, the connecting pin 20 can comprise ferritic steel, for example. The base body 12 preferably consists of a steel with a higher coefficient of expansion than the material of the connecting pin 20; in particular, austenitic steel can be selected as the material for the base body 12. If a low-melting fixing material 16 (for example bismuth-based glass) is selected, a hermetically sealed pressure glazing can be provided in combination with a base body 12 made of austenitic stainless steel. This choice of material can also be advantageous for other embodiments. Of course, other material combinations are possible and are also covered by the invention.

In the following figures, the same components as in figures 1 to 4 are given the same reference numerals.

Figure 5 shows a second embodiment of the invention with a symmetrical feedthrough, which is designed in accordance with the first embodiment. As described with reference to the first embodiment with reference to Figure 4, the electrical feedthrough has a flat, disk-shaped base body 12 with a substantially uniform thickness D and with a through-opening 14 in which a connection pin 20 is held in an insulating manner via a fixing material 16. To avoid repetition, reference is made to the above explanations.

In contrast to the first embodiment, the base body 12 has a circumferential, asymmetrical connecting flange 18a on its outer edge 17, which is designed here in the form of a one-sided step. In addition to connecting to another housing component, e.g. by welding or soldering, such a connecting flange serves to align and center the housing part 10 when assembling a housing or a cover. It can be advantageous if the other housing component has a mating flange that matches the connecting flange. In the second embodiment of the housing part 10 shown, both end faces 21 of the connection pin 20 are also flush with the corresponding surfaces of the fixing material 14.

Figure 6 shows a third embodiment of the invention with a symmetrical feedthrough, which is designed similarly to the first and second embodiments, so that reference is made to the above explanations to avoid repetition. Deviating from the flush arrangement described above, in the third embodiment the connection pin 20 is arranged in the symmetrical feedthrough in such a way that both end faces 21 of the connection pin 20 protrude the same distance beyond the corresponding surfaces of the fixing material 14. This makes it possible, for example, to easily make contact with arresters, contact lugs, etc. As in the second embodiment, in the third embodiment an asymmetrical connection flange 18a is provided on the outer edge 17 of the base body 12, but here it is implemented as a one-sided bevel, chamfer, etc. In principle, combinations of step and chamfer are also possible to form an asymmetrical connection flange. The embodiments shown in Figures 4 to 6 have in common that they have the described symmetrical feedthrough according to the invention. During the manufacture of the housing part 10, it is therefore not necessary to determine on the base body 12 before placing it in the melting mold in which direction any asymmetrical connecting flange 18a of the base body 12 points, since the geometry of the top and bottom of the housing part do not differ except for any features present on the edge. Errors in the orientation of the base body 12 in the finished housing part 10 cannot therefore occur, in contrast to the comparative example of a housing part 10 with electrical feedthrough shown as an example in Figure 3.

The base body 12 of the comparative example from Figure 3 corresponds to the disk-shaped base body 12 shown in Figure 5 and here also has an asymmetrical connecting flange 18a. However, in the comparative example, the fixing material 16 and the connecting pin 20 are not arranged symmetrically to the plane of symmetry S located centrally in the base body plane. In order to ensure that the connecting pin 20 protrudes over the base body 12 on the desired side in the finished housing part 10 when manufacturing a housing part 10 with such an asymmetrical feedthrough and asymmetrical connecting flange 18a, the base body 12 must be oriented in advance during the housing part production so that it is inserted into the melting mold with the correct alignment of the asymmetrical connecting flange 18a. This is complex and errors can occur, especially when a very thin base body 12 is involved (for example for a micro battery) in which the one-sided step or one-sided bevel on the connecting flange is very small.

Figures 7 and 8 show embodiments of the second embodiment of the invention with a symmetrical connecting flange 18b. In the second embodiment according to the invention, the housing part 10 also comprises a base body 12 with a through-opening 14 into which a connection pin 20 is inserted. The connection pin 20, which here has two end faces 21 and a lateral surface, is held in the through-opening 14 in an electrically insulating manner by means of a fixing material 16. The fixing material 16 seals both against an inner wall of the through-opening 14 and against the connection pin 20, so that the through-opening 14 is tightly closed by the fixing material 16 and a metal fixing material feedthrough is formed.

As can be seen, a disk-shaped base body 12 with a substantially uniform thickness D is also used here. A substantially uniform thickness means that the base body 12 has the same thickness outside the area of the through-opening 14 as in an area adjacent to the through-opening 14. The base body 12 is therefore flat and has no reinforcing means produced by forming processes, such as reinforcement, collar, flexible flange or the like. With such a housing part 10, thin, compact housings with a lot of volume inside the housing can be provided.

On its outer edge 17, the flat base body 12 has a symmetrical connecting flange 18b which is arranged symmetrically to a symmetry plane S lying centrally in the base body plane, in that matching bevels or slopes (see Figure 7) or matching steps (see Figure 8) are formed on the edge 17 of the base body 12 on both its upper side and its lower side, ie there is a bevel and/or gradation on both sides. Combinations of bevels and gradations are also possible, as long as the symmetry of the connecting flange 18b is maintained. A base body with a symmetrical connecting flange The flange can also have neither steps nor bevels on the edge 17 (see the base body of Figure 4). A symmetrical connecting flange 18b can also be used for centering, alignment and/or for connecting to another housing component. It can be advantageous if the other housing component has a counter flange that fits the connecting flange.

In the fourth embodiment of the invention shown in Figure 7 and the fifth embodiment of the invention shown in Figure 8, the fixing material 16 and the connection pin 20 are not arranged symmetrically to a plane of symmetry S lying centrally in the base body plane, in contrast to the embodiments described so far, so that the housing part is asymmetrical with respect to the feedthrough, i.e. there is an asymmetrical feedthrough.

In Figure 7, the front side 21 of the connection pin 20 located on the top side of the housing part 10 is at a greater distance from the plane of symmetry S than the front side 21 located on the bottom side. The fixing material 16 is also arranged asymmetrically with respect to the plane of symmetry S. The difference between height H and thickness D is thus distributed asymmetrically between the sides of the housing part 10. As can be seen, the opposite front sides of the fixing material 16 are also arranged essentially parallel to one another starting from the connection pin 20 - except for the contact area between the base body 12 and the fixing material 16. In other words, the fixing material 16 has an essentially uniform height starting from the connection pin 20 - except for the contact area between the base body 12 and the fixing material 16. Towards the contact area between the fixing material and the base body, one front side of the fixing material 16 converges towards the base body 12 (here on the top side). In other words, the height of the fixing material 16 increases on one side starting from the base body 12. Here too, the contact area coincides with the wall of the through-opening 14, ie it lies in the area of the wall of the through-opening. It is shown as an example that the lower end face of the fixing material 16 is flush with the underside of the base body 12. In the fourth exemplary embodiment, both end faces 21 of the connection pin 20 are arranged flush with a surface or end face of the fixing material 16. Of course, different designs are possible, in which the end faces 21 of the connection pin 20 protrude beyond the fixing material on one side or on both sides (see also Figure 8). It can also be seen that in the case of an asymmetrical implementation, one end face 21 of the connection pin 20 can advantageously be arranged flush with one side (here the underside) of the base body 12.

Deviating from the embodiment described in Figure 7, in the fifth embodiment shown in Figure 8, the front side 21 of the connection pin 20 located on the underside of the housing part 10 has a greater distance from the plane of symmetry S than the front side 21 located on the top, while the fixing material 16 is arranged symmetrically with respect to the plane of symmetry S. The difference between height H and thickness D is distributed symmetrically between the sides of the housing part 10. In addition, this embodiment shows by way of example that in a housing part 10 with a symmetrical connecting flange 18b, at least one front side 21 of the connection pin 20 can be arranged to protrude beyond a surface or front side of the fixing material 16.

The designs of an asymmetrical feedthrough described in Figures 7 and 8 are to be understood purely as examples. The features described can also be combined in any other way.

Because the asymmetrical feedthrough is realized with a base body 12 with a symmetrical connecting flange, the manufacturing effort for a housing part 10 is reduced, since the orientation of the base body 12, related on the later top or bottom, during the production of the housing part 10 plays no role. The sides of the housing part 10 only have to be identified during further processing, for example when connecting to other housing parts, arresters, etc.

Figure 9 shows a sixth embodiment of the invention, in which the housing part 10 has both a symmetrical connecting flange 18b, here exemplarily shaped as a step on both sides, and a symmetrical electrical feedthrough, which is designed in accordance with the first embodiment. To avoid repetition, reference is made to the above explanations. It goes without saying that the symmetrical feedthrough can also be implemented differently, e.g. as in the third embodiment, and that the symmetrical connecting flange 18b can alternatively or additionally comprise, for example, a bevel on both sides. Such a symmetrical housing part 10 offers advantages not only in its production, but also in its further processing, since complex measures for determining the orientation of the housing part 10 can be omitted or reduced and the risk of orientation errors is reduced.

Figures 10 to 13 show further embodiments of the invention with symmetrical electrical feedthrough and/or symmetrical connecting flange. Since in the following figures the same components as in Figures 1 to 9 are given the same reference numerals, reference is made to the above statements to avoid repetition and the advantageous further developments are described in more detail below.

In the figures it can be seen that the connection pin 20 has a core 22 made of a first electrically conductive material and that at least on a first side of the electrical feedthrough a first end face of the core 22 is covered with a covering material 24 made of a second electrically conductive material, wherein advantageously the covering material 24 and the fixing material 16 are designed and arranged such that the first electrically conductive material of the core 22 is inaccessible at least on the first side of the electrical feedthrough.

As in the embodiments described above, the connection pin 20 must be adapted in its material properties, in particular with regard to its thermal expansion coefficient, to the requirements of the metal fixing material feedthrough formed. In order to prevent or at least reduce corrosion of the connection pin 20, the material of the connection pin 20 should also advantageously be adapted to the materials used in the storage cell, such as the materials of the current conductors, electrode materials and electrolytes. In order to meet both requirements, an advantageous development provides that the connection pin 20 has a core 22 made of a first electrically conductive material, which is adapted to the requirements of the metal fixing material feedthrough, and has a cover material 24 made of a second electrically conductive material on one end face, which is adapted to the requirements of the storage cell, for example to prevent or at least reduce corrosion. The covering material 24 and the fixing material 16 are advantageously arranged in the electrical feedthrough in such a way that the core material 22 of the connection pin is inaccessible on a first side of the feedthrough on which the covering material 24 is located. For this purpose, the covering material 24 preferably borders directly on the fixing material 16.

The covering material 24 can be located on the side of the electrical feedthrough which faces inwards when a housing is formed. The second electrically conductive material can be applied to the end face of the core 22 of the connection pin 20, for example by means of plating. However, other variants are also conceivable for applying the second electrically conductive material. For example, thin sheets or foils made of the second electrically conductive material can be welded or soldered to the core. 22 or the second electrical material can be applied by electroplating or a vapor deposition process.

With regard to the materials of the components, a multi-part connection pin 20 can, for example, have a core 22 made of ferritic steel as the first electrically conductive material and, on at least one side of the core 22, a covering material 24, 25 made of aluminum or an aluminum alloy as the second electrically conductive material, for example in the case of a design of the housing part for use in a lithium-ion battery. The base body 12 can be made of a steel with a higher coefficient of expansion than the material of the core 22; in particular, austenitic steel can be selected as the material for the base body 12. If a low-melting fixing material 16 is selected, e.g. a bismuth-based glass, a hermetically sealed pressure glazing can be provided in combination with a base body 12 made of austenitic stainless steel. Of course, other material combinations are possible and are also covered by the invention.

In embodiments with symmetrical feedthrough and asymmetrical connecting flange 18a (see Figures 10, 11 ), it is important that the connection pin 20 with core 22 and covering material 24 is constructed symmetrically:

In the seventh embodiment in Figure 10, the core 22 of the connection pin 20 is completely coated 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. Both end faces 21 of the connection pin 20 are here, for example, flush with the corresponding surfaces of the fixing material 14. Alternatively, however, these could also protrude above the fixing material 14. In the eighth embodiment in Figure 11, a second end face of the core 22 opposite the first end face is covered with a further covering material 25 made of a third electrically conductive material, which is selected to be identical to the second electrically conductive material. In addition, a lateral surface of the core 22 of the connection pin 20 remains free of the covering material 24. This ensures that the covering material 24 does not change the properties of the metal fixing material feedthrough. The two materials can thus be selected completely independently of one another in order to achieve optimal adaptation to the requirements of the storage cells inside the housing and on the outside of the housing as well as to the formation of the metal fixing material feedthrough. Both end faces 21 of the connection pin 20 protrude here, for example, over the corresponding surfaces or end faces of the fixing material 14. Because the covering material 24 and the fixing material 16 are designed and arranged such that the first electrically conductive material of the core 22 is inaccessible on both sides of the electrical feedthrough, the core is protected against corrosion and can also be better contacted.

In embodiments with a symmetrical connecting flange 18b (see Figures 12 and 13), the connecting pin 20 with core 22 and covering material 24 can also be constructed asymmetrically:

In the ninth embodiment in Figure 12, the end faces 21 of the connecting pin 10 have different distances from the plane of symmetry S and one end face 21 of the connecting pin 20 protrudes above the fixing material 16, while the other end face 21 can be flush. In contrast to the previously described embodiments, a covering material 24 is also only provided on one side of the core 22, whereby in this embodiment the core 24 is accessible from the side, which can be possible if, for example, the material of the core 24 is not at risk of corrosion or the corrosion is prevented by other measures. The covering material 24 can in this case, for example, be used for serve to improve electrical contact. Alternatively, the arrangement of the covering material 24 could be selected such that, in conjunction with the fixing material 16, the first electrically conductive material of the core 22 is not accessible, in that the fixing material 16 directly adjoins the covering material 24.

In the tenth embodiment in Figure 13, the connecting flange and the feedthrough are symmetrical, while the connection pin is asymmetrical. A second end face of the core 22 opposite the first end face is covered with a further covering material 25 made of a third electrically conductive material, which is selected to be different from the second electrically conductive material. If different materials are selected, the second electrically conductive material in particular can be adapted to the requirements of the materials of a storage cell and the third electrically conductive material can be optimized, for example, for simple and secure connection to electrical connections. Welding properties or soldering properties can be used as a criterion for the material selection, for example. - If the covering materials had alternatively been selected to be the same in the embodiment shown, a housing part 10 would have been realized with a symmetrical feedthrough, symmetrical connection pin and symmetrical connecting flange.

Figure 14 shows a section of a schematic detailed drawing, the features and advantageous variants of which - if necessary with appropriate adaptation - can be combined with any embodiment, in particular the embodiments described above. A symmetrical implementation is shown purely as an example. Of course, advantageous asymmetrical implementations can also be implemented. When the housing part 10 is shown in vertical cross-section, the base body 12 has a distance A from the connection pin 20 arranged in its through-opening 14, which is filled with fixing material 16. The distance A is thus the distance between the wall of the through-opening 14 and the wall of the connection pin 20. The connection pin 20 has a thickness I.

As in the other figures, it can also be seen here that in the area of the through-opening 14, the height H of the fixing material 16 is greater than the thickness D of the base body 12. Both end faces of the fixing material 16 are arranged here so as to protrude beyond a surface of the base body 12. The opposite end faces of the fixing material 16 are arranged essentially parallel to one another starting from the connection pin 20, except for the contact area between the base body 12 and the fixing material 16. In other words, the fixing material 16 has an essentially uniform height H starting from the connection pin 20, except for the contact area between the base body and the fixing material.

Towards the contact area between the fixing material and the base body, both end faces of the fixing material 16 converge towards the base body 12. In other words, the height of the fixing material 16 increases from the base body 12 towards the connection pin 20. In the case of the solid line of the fixing material 16, the contact area between the surface of the fixing material 16 and the base body 12 coincides with the wall of the through-opening 14, but this does not have to be the case, see the dashed extension of the fixing material, which illustrates a fixing material overflow 28, which is described further below.

Since the slope or curvature 26 of the fixing material contour can be freely adjusted in the area in which the surface of the fixing material 16 comes into contact with the base body 12, volume fluctuations in the fixing material material and variations in the dimensions of the components. Depending on the volume of the fixing material and the structural conditions, the slope or curvature 26 can be steeper or flatter, and the fixing material can even cover the edge of the through-opening and form a fixing material overflow (see below).

When looking at the fixing material 16 shown with a solid line, the desired essentially uniform height H of the fixing material is reached in the example shown at the latest after approximately 15% of the distance A between the base body 12 and the connecting pin 20, whereby the reference point, i.e. the starting point for the observation, is the base body. A plateau P is thus quickly formed in which the fixing material 16 has an essentially constant height and the end faces of the fixing material run essentially parallel to one another. A plateau P with a constant height of the fixing material advantageously extends over at least 85% of the distance between the base body and the connecting pin.

In an advantageous variant of the housing part 10, the fixing material 16 not only protrudes beyond the surface of the base body 12, but also covers the edge of the through-opening 14 and also an area of the top of the base body adjacent to the through-opening 14 (see dashed line of the fixing material). In the example shown, the coverage is symmetrical on both sides of the base body. However, asymmetrical variants and/or one-sided variants are also possible. A fixing material overflow 28 or a fixing material coverage is realized. This makes a reservoir for the fixing material 16 even larger and the insulation effect is increased. Compared to the variant without fixing material coverage 28, the width of the plateau P is even larger. A plateau with an essentially constant height of the fixing material extends here over more than 100% of the distance A between the base body 12 and the connection pin 20. It can also be seen in Figure 14 that in the housing part 10 an imaginary tangent applied to the surface of the fixing material 16 at the contact point with the connecting pin forms a contact angle a with the connecting pin 20 of approximately 90°. In other words, there is a right angle, naturally within the limits of the usual manufacturing tolerances, here preferably 90° with a deviation of +/- 2°. This provides a hermetic connection and at the same time a compact feedthrough. A larger contact angle outside the mentioned deviation, i.e. an obtuse angle between the tangent and the connecting pin, leads to a trench in the contact area between the fixing material 16 and the connecting pin 20, which makes it more difficult to produce a hermetically sealed feedthrough. A smaller contact angle outside the mentioned deviation, i.e. an acute angle between the tangent and the connecting pin, exists when there is a pull of the fixing material 16 on the circumference of the connecting pin 20, also called the meniscus. This is disadvantageous because there is a risk that fixing material will get onto the front side 21 of the connection pin 20.

Figure 14 shows schematically the ideal case of a symmetrical feedthrough in which the plane of symmetry S located centrally in the base body plane and a connection pin plane of symmetry S' located centrally in the connection pin plane lie one above the other, i.e. they have no distance from each other. Due to manufacturing tolerances in the individual components of the housing part and the shapes required for production, however, there may be a deviation between the planes of symmetry, which is preferably less than 4% of the thickness I of the connection pin 20.

Only a few of the possible feature combinations have been described above using Figures 4 to 14 as examples. Many other combinations of features relating to a feedthrough (symmetrical, asymmetrical), features relating to a connecting flange (symmetrical, asymmetrical) and features relating to a connection pin (symmetrical, asymmetrical) are possible and included in the invention.

The invention provides flat, compact housing parts 10 with improved symmetry and lower manufacturing costs, which are particularly suitable for an electrical device, in particular for an electrical energy storage device. The housing parts can be used to provide storage devices that are themselves so compact that as much volume as possible is made available inside the housing, whereby the storage device, e.g. battery and/or capacitor, can have as high a capacity as possible. The housing parts according to the invention are particularly advantageous for micro batteries. However, the invention can also be used for larger storage devices and other electrical devices, for example sensor housings. In general, the invention can be used for electrical feedthroughs of all types, for example also for housings for electronic components. In addition, the invention provides a universally usable standard feedthrough that is independent of the dimensions of other housing components and/or the housing.

list of reference symbols

10 housing part

12 basic bodies

14 passage opening

16 fixing material

17 outer edge of 12

18a asymmetrical connecting flange

18b symmetrical connecting flange

20 pin connector

21 front side of 20

22 core

24 covering material

25 additional covering material

26 curvature

28 Fixing material overflow

30 flexible flange d1 first thickness in the prior art d2 second thickness in the prior art

W width in the state of the art

D thickness of 12

S symmetry plane of 12

S‘ symmetry plane of 20

H height of 16

A distance between 12 and 20

I thickness of 20

P Plateau a Contact angle between 16 and 20

Claims

claims 1 . Housing part (10), in particular for an electrical storage device, with an electrical feedthrough comprising a base body (12) with a through-opening (14) and a connection pin (20) arranged in the through-opening (14), which is held in the through-opening (14) in an electrically insulating manner by means of a fixing material (16), characterized in that the base body (12) of the housing part (10) is flat and disc-shaped with a substantially uniform thickness (D) and a height (H) of the fixing material (16) is greater than the thickness (D) of the base body (12), wherein i) the base body (12) has a symmetrical feedthrough in that the fixing material (16) and the connection pin (20) are arranged symmetrically to a symmetry plane (S) lying centrally in the base body plane, and/or ii) the base body (12) has a symmetrical connecting flange (18b) on its outer edge (17), which is symmetrical to a symmetry plane (S) lying centrally in the plane of symmetry (S) lying on the plane of the base body. 2. Housing part (10) according to claim 1, characterized in that the base body (12) with the symmetrical passage has a connecting flange on the outer edge, which preferably has a one-sided step or one-sided chamfer. 3. Housing part (10) according to claim 1 or 2, characterized in that the end faces (21) of the connection pin (20) are each arranged flush with a surface of the fixing material (16). 4. Housing part (10) according to claim 1 or 2, characterized in that both end faces (21) of the connection pin (20) are arranged to protrude beyond a surface of the fixing material (16). 5. Housing part (10) according to one of claims 1 to 4, characterized in that the base body (12) has a thickness in the range 0.1 mm to 1 mm, preferably 0.15 mm to 0.8 mm, in particular 0.15 mm to 0.6 mm. 6. Housing part (10) according to one of claims 1 to 5, characterized in that the material of the base body (12) and/or material of the connection pin (20) are selected from steel, in particular ferritic, austenitic or duplex steel, stainless steel, stainless steel, iron-nickel alloys, iron-nickel-cobalt alloys, KOVAR, molybdenum, titanium, titanium alloy, aluminum or aluminum alloy. 7. Housing part (10) according to one of claims 1 to 6, characterized in that the connection pin (20) has a core (22) made of a first electrically conductive material and that at least on a first side of the electrical feedthrough a first end face of the core (22) is covered with a covering material (24) made of a second electrically conductive material, wherein the covering material (24) and the fixing material (16) are advantageously designed and arranged such that the first electrically conductive material of the core (22) is inaccessible on the first side of the electrical feedthrough. 8. Housing part (10) according to claim 7, characterized in that a second end face of the core (22) opposite the first end face is covered with a further covering material (25) made of a third electrically conductive material, which is selected to be identical or different to the second electrically conductive material. 9. Housing part (10) according to one of claims 7 or 8, characterized in that the second electrically conductive material and/or the third electrically conductive material of the connection pin (20) is selected from aluminum, an aluminum alloy, AlSiC, copper, a copper alloy, molybdenum, nickel or nickel alloys, palladium, silver or gold. 10. Housing part (10) according to one of claims 1 to 9, characterized in 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. Housing part (10) according to one of claims 1 to 10, characterized in that a first expansion coefficient of the base body (12) is greater than a second expansion coefficient of the fixing material (16) or that the expansion coefficients of the base body (12) and the fixing material (16) are adapted to one another. 12. Housing part (10) according to one of claims 1 to 11, characterized in that the fixing material (16) and its connection to the wall of the through-opening (14) and the connecting pin (20) is designed in such a way that a safety valve function is provided above a predetermined pressing force, wherein the predetermined pressing force is set by one or more of the following measures: a. Selecting the thickness of the glazing, b. Selecting the fixing material (16), c. Selecting the proportion of bubbles in the fixing material (16), d. Structuring the surface of the fixing material (16) by adjusting the shape of a fixing material molded body before glazing, e. Structuring the surface of the fixing material (16) during glazing, f. laser processing of the surface of the fixing material (16) after glazing, g. one- or two-sided introduction of notches or tapers into the fixing material (16) and/or h. introduction of notches or tapers into the connecting pin (20) and/or the base body (12). 13. Electrical storage device, in particular a battery, preferably a microbattery, or a capacitor, comprising a housing with a housing part (10) according to one of claims 1 to 12.