Electrical feedthrough and energy storage device with such a feedthrough - Patents.com

Abstract

The present invention provides an electrical feedthrough (10) for an electrical storage device, in particular comprising a base (12) with a through opening (14) and a connection pin (20) disposed in the through opening (14) and held in the through opening (14) in an electrically insulating manner via a fastening material (16). It is further specified that the connection pin (20) has a core (22) made of a first conductive material, a first side of the core (22) being covered with a cover material (24) made of a second conductive material, at least on a first surface of the electrical feedthrough (10), and the connection pin (20) and the fastening material (16) are constructed and arranged such that the first conductive material of the core (22) is inaccessible on the first surface of the electrical feedthrough (10).

Description

[Technical field]

[0001] The invention relates in particular to an electrical feedthrough for an electrical storage device, which comprises a base with a through opening and a connection pin arranged in the through opening and held therein in an electrically insulating manner via a fastening material. Another aspect of the invention relates to an electrical energy accumulator comprising at least one such feedthrough. [Background technology]

[0002] Electrical energy accumulators, such as batteries or capacitors, including supercapacitors, are used in many applications for storing and supplying electrical energy. Electrical energy accumulators generally include a housing and at least one storage cell accommodated in the housing. Electrical contact can be made from the outside to the storage cell via at least one electrical feedthrough in the housing.

[0003] In the present invention, a battery is understood to mean a disposable battery or a storage battery that can be disposed of and / or recycled after its discharge. Storage batteries, preferably lithium-ion batteries, are provided for various applications, such as portable electronic devices, mobile phones, power tools, and especially electric vehicles. These batteries can replace traditional energy sources, such as lead-acid batteries, nickel-cadmium batteries, or nickel-metal halide batteries. The use of batteries in sensors or in the Internet of Things is also possible.

[0004] Supercapacitors, also called supercaps, as generally known, are electrochemical energy storage devices with particularly high power density. Supercapacitors, unlike ceramic capacitors, thin film capacitors and electrolytic capacitors, do not have a dielectric in the conventional sense. In particular, the storage method of static storage of electric energy in supercapacitors is realized by charge separation in double-layer capacitance and electrochemical storage of electric energy by charge exchange using redox reactions in pseudocapacitance.

[0005] Supercapacitors include in particular hybrid capacitors, in particular lithium-ion capacitors. The electrolyte generally comprises a solvent in which a conductive salt, generally a lithium salt, is dissolved. Supercapacitors are preferably used in applications requiring a large number of charge / discharge cycles. Supercapacitors can be used particularly advantageously in the automotive field, in particular in the area of ​​braking energy recovery. Naturally, other applications are possible as well, which are encompassed by the invention.

[0006] Lithium-ion batteries as storage devices have been known for many years, see for example "Handbook of Batteries", edited by David Linden, 2nd ed., McCrawhill, 1995, chapters 36 and 39.

[0007] WO 2021 / 185648 A1 discloses a microbattery which is distinguished by a particularly compact construction form, the metal-fastening material feedthroughs for the electrical connections of which can be configured as compression seals, which results in a particularly reliable sealing of the feedthroughs.

[0008] A disadvantage of known metal-fixing material feedthroughs with compression sealing or adapted feedthroughs is that these feedthroughs cannot currently be produced reliably with contact pins made of any material. For example, to avoid corrosion, contact pins made of a material adapted to the material of the battery or capacitor are desirable. Correspondingly, the object of the present invention is to provide an electrical feedthrough whose contact pins can be adapted both to the requirements of the battery and to the requirements of the metal-fixing material feedthrough. Summary of the Invention [Means for solving the problem]

[0009] The invention proposes an electrical feedthrough, in particular for electrical storage devices. The electrical feedthrough 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 fastening material. It is further specified that the connection pin has a core made of a first conductive material, at least on a first surface of the electrical feedthrough, a first side of the core is covered by a cover material made of a second conductive material, and the connection pin and the fastening material are constructed and arranged in such a way that the first conductive material of the core is inaccessible on the first surface of the electrical feedthrough. For this purpose, the fastening material is in direct contact with the cover material.

[0010] Here, the base body, the fastening material and the contact pin form a metal-fastening material feedthrough which closes the through opening of the base body. The formed feedthrough is preferably hermetically sealed. A hermetic seal is one that has a resistance of 1×10 at a pressure differential of 1 bar. -8 mbar l / s He leak rate.

[0011] The substrate may in particular be a housing part for forming a housing for an electrical storage device. For example, the substrate may be configured as a cover part, which, together with a cup-shaped housing part, may be coupled to the housing for the electrical storage device. The electrical storage device may in particular be a battery or a capacitor, including a supercapacitor, in which the housing generally accommodates one or more storage cells, which can be electrically contacted from the outside via an electrical feed-through as a connection terminal. The feed-through may be configured as a multi-pole feed-through, in which the substrate has a number of feed-through openings, in each of which a respective connection pin is held via a fastening material.

[0012] It is advantageous if the first side of the electrical feedthrough, to which the first conductive material of the core is inaccessible, is the side which faces inward when forming the housing. The first side having the cover material therefore faces inward when forming the housing. An alternative arrangement, in which the first conductive material of the core is inaccessible from the side which faces outward when forming the housing, is of course likewise possible and likewise advantageous.

[0013] The proposed connection pin comprises at least two different materials, the first conductive material of the core being preferably selected according to the requirements of the metal-fixing material feedthrough. For this, the first conductive material can be selected in particular taking into account its thermal expansion coefficient and its resistance to deformation. The second conductive material is preferably selected according to the requirements of the electrical storage device. The second conductive material can be selected in particular taking into account its chemical resistance and its electrochemical potential with respect to the material of the storage cell.

[0014] The contact pin may have, for example, a cylindrical shape, the outer side of the tube facing the fastening material and at least one of the side surfaces being covered by the cover material. Besides the cylindrical shape, general cylindrical shapes with other side surface shapes are also conceivable, for example ovals or rectangles with rounded corners. The contact pin may further have, for example, a so-called nailhead shape, which may be formed, for example, by two tubes that are in contact with each other. In this case, the first side surface of such a nailhead-shaped contact pin is formed by the side surface of the tube with the larger side surface and the second side surface is formed by the side surface of the tube with the smaller side surface.

[0015] In addition to covering the first side of the core with a cover material, it is also possible to configure the second side of the core, opposite the first side, to be covered with another cover material made of a third conductive material. The third conductive material can be selected separately from the second conductive material or can be selected the same. In particular, in the various selections, the second conductive material can be adapted to the material requirements of the storage cell, for example, the third conductive material can be optimized for easy and reliable connection with the electrical connection. For example, welding or brazing properties can be used as a criterion for material selection.

[0016] In one variant of the invention, the outer surface of the core facing the fixing material is at least partially free of cover material and directly adjoins the fixing material. The outer surface of the core is preferably completely free of cover material. In another variant of the invention, the surface of the core is completely covered with cover material, so that in particular the outer surface is also completely covered by cover material.

[0017] The melting point of the fastening material is preferably selected to be lower than the melting points of all materials of the contact pin, which ensures that the contact pin is not damaged when producing the metal-fastening material feed-through, for example under the use of temperature treatment steps for sintering or glass sealing the fastening material.

[0018] In such a temperature treatment step, the fastening material can be obtained, for example, from a compacted member comprising a glass powder or a glass-ceramic powder or a ceramic powder, the glass powder being composed of or containing a partially crystallizable glass, such that during the temperature treatment the partially crystallizable glass is ceramized to obtain a glass-ceramic.

[0019] The second conductive material and / or the third conductive material are preferably applied to the side of the core using plating, electroplating, coating, vapor deposition, welding, or brazing. When only a relatively small thickness of cover material is applied, electroplating, coating, and vapor deposition are preferred. Conversely, when a relatively large thickness of cover material is applied, plating, welding, and brazing are preferred.

[0020] In plating, the starting materials, i.e., for example, the cover material and the core material, are generally provided in the form of a plate or tape and are superimposed and joined to one another by rolling. In brazing or welding, for example, the cover material can be placed on the core material in the form of a thin plate or sheet and welded or brazed thereto.

[0021] Vapor deposition methods include, for example, physical vapor deposition (PVD), such as sputtering, chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD).

[0022] Regardless of the type of application, the cover material is preferably arranged without openings or defects so that the corresponding side of the core is completely covered, in particular to avoid contact between the first conductive material and material from the inside of the energy accumulator.

[0023] Furthermore, the cover material is preferably selected and arranged so as to be suitable for soldering or welding electrical contacts, such as tab contacts, etc. Correspondingly, the cover material is preferably configured so as to be suitable for soldering or welding electrical contacts and such that no cracks or openings occur in the cover material during soldering or welding.

[0024] One or both sides of the contact pin are preferably arranged flush with the surface of the base body. If the base body has regions of different thickness, it is preferred that one or both sides terminate flush with the surface bordering the through-opening of the base body. In particular in combination with a fastening material that terminates flush with the surface of the base body, this allows a flat shape of the electrical feedthrough, which advantageously has a construction height that is as small as possible.

[0025] Alternatively, it is preferred that one or both lateral faces of the contact pin are arranged to protrude beyond the surface of the base body. If the base body has regions of different thickness, it is preferred that one or both lateral faces protrude beyond the surface bordering the through-opening of the base body. This results in a high contact surface, which allows for simple electrical contact of the contact pin, for example by welding a tab contact.

[0026] The material of the substrate and / or the first conductive material of the core of the contact pin is preferably selected from steel, in particular ferritic, austenitic or duplex steel, rust-free steel, stainless steel, iron-nickel alloys, iron-nickel-cobalt alloys, kovar, molybdenum, titanium, titanium alloys, aluminium or aluminium alloys.

[0027] A preferred embodiment has a substrate made of austenitic steel and a contact pin with a core made of ferritic steel.

[0028] The second and / or the third conductive material of the contact pin is preferably selected from aluminium, aluminium alloys, AlSiC, copper, copper alloys, molybdenum, nickel or nickel alloys, palladium, silver or gold.

[0029] A preferred embodiment of the contact pin according to the invention has a core made of stainless steel, in particular a ferritic stainless steel, and a cover material made of aluminum or an aluminum alloy.

[0030] However, other material combinations are also preferred, in which the melting point of the second and / or third conductive material of the contact pin is lower than the melting point of the first conductive material of the core.

[0031] The fixing material is preferably a glass, a glass ceramic or a ceramic or comprises a glass, a glass ceramic or a ceramic.

[0032] Preferred glasses include technical glasses, especially oxide glasses, which are preferably chemically resistant to common materials in connection with electrical energy storage devices.

[0033] In the case of technical glasses, the fixing material is, for example, an aluminum borate glass containing Al2O3 and B2O3 or, for example, a bismuth glass containing Bi2O3 as glass former. Alternatively, glasses containing lead oxide as glass former, in particular glasses from the PbO·B2O3 system, or vanadium-containing glasses may be used as fixing materials.

[0034] For glass-metal feedthroughs, a suitable glass is selected as fastening material according to its properties, such as its melting temperature and / or expansion coefficient. Glasses with low melting temperatures may be advantageous. Particularly advantageous are glasses whose melting temperatures are below the melting point of aluminum or aluminum alloys. In electrical feedthroughs for electrical storage devices, such as batteries, capacitors or supercapacitors, it may be preferred if the fastening material comprises or consists of a bismuth-based glass with Bi2O3 as glass former or a lead-based glass with PbO as glass former.

[0035] To produce the electrical feedthrough, the fastening material or precursor material in the form of a shaped body can be prepared. The shaped body can have the shape of a hollow cylinder, for example. To construct the electrical feedthrough, a connection pin is inserted inside this hollow cylinder, which itself is inserted into an opening in a substrate. The metal pin is then glass-sealed in the opening by a heat treatment, and the fastening material is intimately bonded to the material of the connection pin and the material of the substrate.

[0036] If the substrate is configured as a housing part for an electrical energy storage device, for example as a cover part of a microbattery, the substrate has for example a thickness in the range of 0.1 mm to 1 mm, preferably 0.2 mm to 0.6 mm.

[0037] The base body preferably has a first thickness d1 outside the area of ​​the through-opening and an increased second thickness d2 in a reinforcement area of ​​width W bordering the through-opening. If the metal-fastening material feedthrough is configured as a compression sealing, the width W is selected so that a sufficient pressing force can be exerted on the fastening material by the base body. For example, the width W is selected for this purpose in the range of 0.6 mm to 1 mm.

[0038] This increased thickness of the reinforcing region can be achieved, for example, by providing a thickened region of the base of the housing part, by providing a collar and / or by providing a reinforcing portion. By selecting the thickness of the base or by providing a thickened region, the glass seal length, where the fastening material and the material of the base of the housing part are joined, can be influenced.

[0039] In one variant, the housing part has a collar which forms an inner wall with a height greater than the material thickness of the remaining housing part, in particular with the thickness of the housing part configured as a cover or with the thickness of the wall of the housing part configured as a cup.

[0040] The collar is preferably configured as a highly curved and deformed collar, the housing part and the collar being in particular integral.

[0041] In order to avoid, in particular after glass sealing, for example damage to the glass, ceramic or glass-ceramic material due to temperature effects, it is advantageous if the base body contains a flexible flange for connecting the base body to a further component of the housing, such as a component part of the housing. The flange itself contains an area, i.e. a so-called joint area, where the further component is connected to the base body. The connection to the base body can be made by welding, in particular ultrasonic welding or brazing. The welded joint is preferably such that the joint is sufficiently gas-tight, preferably with a pressure difference of 10 bar. -8 This is done so that a He leak rate of less than mbar l / sec is set.

[0042] The flexible flange can be obtained in a very simple way. For example, the base body can be embodied as a sheet metal part having a thickness d2, which is pressed down to a thickness d1, and after pressing down, this part with the thickness d1 is deformed so that the flexible flange is formed. In this case, the original thickness d2 remains around the area of ​​the opening, so that the area bordering the opening is reinforced. It is also possible to form a sheet metal with a thickness d1 into a flexible flange, and the drawn sheet or the collar formed by deforming the sheet metal can accommodate a glass seal. Glass sealing to the drawn flexible flange, in particular to the collar of the flexible flange, is possible in particular if the flexible flange and the drawn area contain austenitic or two-phase stainless steel as material.

[0043] In an advantageous embodiment, instead of or in addition to the flexible flange, the base body can be provided with a load-relief device, which advantageously comprises at least one groove or recess, preferably at least one surrounding groove or surrounding recess. Instead of the groove, a row of adjacent perforations can also be provided.

[0044] The load-relieving device allows the heat flow through the substrate to be reduced, i.e. a thermal barrier to be obtained and / or the mechanical load of the substrate in the direction perpendicular to the axis of the contact pin to be reduced, since the substrate is deformable, preferably reversibly, in the direction perpendicular to the axis of the contact pin, so that the fastening material is subjected to less stress, in particular no tensile stresses acting on the fastening material and thus reducing its compression, which improves the hermeticity of the feed-through under thermal and mechanical loads.

[0045] In a first advantageous variant, the load-relieving device, in particular the groove or recess, is arranged on a second side of the electrical feedthrough, which faces outward when forming the housing. In an alternative advantageous second variant, the load-relieving device, in particular the groove or recess, is arranged on a first side of the electrical feedthrough, which faces inward when forming the housing. In a particularly advantageous third variant, the load-relieving device comprises at least two grooves or recesses on oppositely arranged sides of the base body.

[0046] As a glass material or glass ceramic material, for example, an aluminum borate glass having the main components Al2O3, B2O3, BaO and SiO2 is used. The expansion coefficient of such a glass material is preferably 9.0 to 9.5 ppm / K or 9.0 to 9.5 × 10 -6 / K. If, for example, bismuth glass is used, the expansion coefficient is, for example, about 10.5×10 -6 / K.

[0047] In order to achieve a particularly good seal between the metal parts, i.e. the base and the connection pins, and the fastening material, the electrical feedthrough can be configured in the form of a compression seal. In this case, the thermal expansion coefficient of the base is selected to be greater than that of the fastening material, so that after the temperature treatment, in which the fastening material is glass-sealed in the through-opening, the base contracts more than the fastening material. As a result, pressing forces are exerted permanently by the base on the fastening material. These pressing forces preload the fastening material, resulting in a particularly stable seal.

[0048] Correspondingly, it is preferred that the thermal expansion coefficient of the substrate is greater than that of the fastening material. Particularly preferably, the thermal expansion coefficient of the substrate during compression sealing is selected to be at least 5%, preferably at least 10%, particularly preferably at least 20%, most preferably at least 50% greater than that of the fastening material.

[0049] The preload for compression sealing is essentially determined by the difference in the coefficients of expansion between the base material and the fastening material.

[0050] The expansion coefficient of the substrate is preferably 12×10 -6 1 / K~19×10 -6 1 / K, and the expansion coefficient of the fixing material is 9×10 -6 1 / K~11×10 -6 It is within the range of 1 / K.

[0051] The coefficient of expansion of the glass, ceramic or glass-ceramic material can be modified, if necessary, by incorporating fillers into the glass, ceramic or glass-ceramic material, whereby the thermal expansion coefficient can be set by selecting the type and amount of filler.

[0052] The coefficient of expansion of the core of the contact pin is preferably less than 6×10 -6 1 / K~11×10 -6 Correspondingly, when implementing the feedthrough as a compression seal, the coefficient of expansion of the core is preferably adapted to or chosen slightly smaller than the coefficient of expansion of the fastening material.

[0053] For compression sealing, for example, about 16 x 10 -6 Austenitic steel with an expansion coefficient of 1 / K and approximately 10.5×10 -6 Bismuth-based glass with an expansion coefficient of 1 / K and approximately 10×10 -6 It may be combined with a core made of ferritic steel having an expansion coefficient of 1 / K.

[0054] As an alternative to compression sealing, the coefficients of expansion of the base body and the fastening material can be adapted to one another, preferably with a difference of less than 5%.

[0055] Matched feedthroughs are in particular those with a substantial expansion coefficient of at most 1×10 -6This is understood to differ by 1 / K, in particular to be substantially the same. The coefficient of expansion of the core of the contact pin is preferably likewise adapted to the coefficient of expansion of the fastening material.

[0056] Where values ​​are given above for coefficients of expansion in relation to compression sealing or glass sealing of materials, these values ​​relate to the linear thermal expansion coefficient α in the temperature interval 20-300 °C, as generally given in relation to glass-to-metal feedthroughs.

[0057] Generally, a housing for an energy storage device is provided with a safety valve and / or a target breaking point as a safety element in order to check and remove the safety valve and / or the target breaking point in the event of an internal overpressure. The electrical feedthrough preferably has such a safety element. For this purpose, it is preferable to select a push-out force for the connecting pin held by the fastening material, so that the connecting pin is pushed out when a predetermined push-out force is exceeded. Such an adaptation of the push-out force is known, for example, from German Utility Model No. 202020106518.

[0058] The fastening material and its joint with the wall of the through opening and the connecting pin are preferably configured to provide a safety valve function via a predetermined pushing-out force, which is achieved by one or more of the following means: a. Selection of glass sealing thickness; b. Selection of fixing materials; c. Selection of the proportion of air bubbles in the fixing material; d. Structuring the surface of the fastening material by setting the shape of the fastening material moulding before glass sealing; e. Structuring the surface of the fastening material during glass sealing; f. Laser processing of the surface of the fixing material after glass sealing; g. The introduction of notches or tapers into the fastening material on one or both sides, and / or h. Set by the introduction of a notch or taper in the contact pin and / or base.

[0059] The second conductive material and / or the anchoring material are preferably selected to be stable to electrolytes, in particular aqueous and / or non-aqueous electrolytes. It is particularly preferred if the material of the feed-through has high chemical resistance to non-aqueous battery electrolytes, in particular carbonate mixtures with carbonates, preferably LiPF6, preferably with conductive salts.

[0060] Another aspect of the invention is to provide an electrical storage device. The proposed electrical storage device is in particular configured as a battery or a capacitor, including a supercapacitor, and includes a housing with at least one electrical feedthrough as described herein. The electrical storage device further preferably includes at least one storage cell, in particular a battery cell or a capacitor cell.

[0061] The base body of the electrical feedthrough is preferably configured as a housing part, in particular as a cover, which is preferably hermetically sealed and joined to another housing part, thereby forming a hermetically sealed housing for the electrical storage device. For example, to form the housing, the cover together with the electrical feedthrough is joined to the cup by welding. A hermetic seal here means that the housing is hermetically sealed with a pressure differential of 1 bar and is 10 -8 This is understood to mean having a He leak rate of less than mbar l / sec.

[0062] The invention will be explained in more detail below on the basis of the drawings, without being limited to these drawings. [Brief description of the drawings]

[0063] [Figure 1] FIG. 2 shows a first embodiment of an electrical feedthrough in which the contact pins are implemented flush. [Diagram 2] FIG. 2 shows a second embodiment of an electrical feedthrough in which the surfaces of the contact pins protrude beyond the base. [Diagram 3] FIG. 13 shows a third embodiment of an electrical feedthrough in which the core of the contact pin is covered on both sides and provided with a reinforcement region. [Figure 4] FIG. 4 shows a fourth embodiment of an electrical feedthrough with a flexible flange. [Diagram 5] FIG. 5 shows a fifth embodiment of an electrical feedthrough in which the core of the contact pin is completely coated. [Figure 6] FIG. 6 shows a sixth embodiment of an electrical feedthrough with a flexible flange. [Figure 7] FIG. 7 shows a seventh embodiment of an electrical feedthrough with a load reduction device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] 1 shows a first embodiment of an electrical feedthrough 10. The electrical feedthrough 10 includes a base 12 with a through opening 14 into which a connecting pin 20 is inserted. The connecting pin 20 is held in the through opening 14 in an electrically insulating manner via a fastening material 16. The fastening material 16 seals against the inner wall of the through opening 14 and against the connecting pin 20, so that the through opening 14 is hermetically closed by the fastening material 16, forming a metal-fastening material feedthrough.

[0065] The illustrated electrical feedthrough 10 is particularly suitable for use in connection with electrical storage devices, such as batteries, in particular microbatteries and capacitors. Correspondingly, the base 12 can be a constituent part of a housing for such an electrical storage device, for example a battery cover. In this case, the connection pins 20 constitute, for example, connection terminals of the electrical storage device. To form a housing for the electrical storage device, the base 12 of the electrical feedthrough is coupled to a further housing part. If the base 12 is configured as a cover part, the housing for the electrical storage device can be formed by coupling the cover part and the cup part. Inside such a storage device, at least one storage cell, for example a battery cell or a capacitor cell, is generally arranged. To form an electrical connection, a connection part of such a storage cell can be electrically conductively connected to the connection pin 20 and to another connection part to another housing part. Naturally, it is also possible to configure a number of through openings 14 in the base 12 and to arrange a number of connection pins 20 therein, thereby providing a multi-pole feedthrough.

[0066] 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 to be formed. In order to prevent or at least reduce corrosion of the connection pin 20, the material of the connection pin 20 should furthermore be adapted to the materials used in the storage cell, for example the material of the current collector, the electrode material and the electrolyte. In order to fulfil both requirements, it is specified according to the invention that the connection pin 20 has a core 22 made of a first conductive material, which is adapted to the requirements of the metal-fixing material feedthrough, and on one side a cover material 24 made of a second conductive material, which cover material 24 is adapted to the requirements of the storage cell in order to avoid or at least reduce corrosion. Here, the cover material 24 and the fixing material 16 are arranged in the electrical feedthrough 10 in such a way that the core material 22 of the connection pin is inaccessible on the first side of the feedthrough, on which the cover material 24 is located. For this, the cover material 24 is in direct contact with the fixing material 16. The cover material 24 is located here on the side of the electrical feedthrough 10 which faces inwards when forming a housing. The second conductive material may be applied to the side of the core 22 of the connection pin 20, for example also by means of plating. However, other variants are also conceivable for applying the second conductive material. For example, a sheet or film of the second conductive material can be joined to the core 22 by means of welding or brazing, or the second electrical material can be applied by electrolytic plating methods or by vapor deposition.

[0067] In the first embodiment of FIG. 1, the outer surface of the core 22 of the contact pin 20 remains free of the cover material 24. This ensures that the properties of the metal-fixing material feed-through are not changed by the cover material 24. Both materials can therefore be selected completely independently of each other in order to achieve an optimal match to the requirements of the storage cell inside the housing and the configuration of the metal-fixing material feed-through. For example, when configuring the electrical feed-through 10 for use in a lithium-ion battery, aluminum can be used as the cover material 24. If the metal-fixing material feed-through is configured as a compression sealing, the first conductive material for the core 22 of the contact pin can be, for example, stainless steel, so that the core 22 does not deform when a pressing force is generated.

[0068] In the embodiment of the electrical feedthrough 10 shown in FIG. 1, both side surfaces of the connection pin 20 are implemented flush with the corresponding surfaces of the substrate 12. The total thickness of the connection pin 20 therefore corresponds to the thickness of the substrate 12 in this embodiment. Furthermore, in this embodiment, the surface of the fastening material 16 is continuous flush with the surface of the substrate 12 and with the side surfaces of the connection pin 20. However, it is also conceivable that the fastening material 16 protrudes beyond the surface and partially covers the connection pin 20 and / or adjacent areas of the substrate 12. Alternatively, it is also conceivable that one or both side surfaces of the connection pin 20 protrude beyond the corresponding surface of the substrate 12. This is exemplarily shown in FIG. 2.

[0069] FIG. 2 shows a second example of the electrical feedthrough 10, in which the surface of the connection pin 20 protrudes beyond the base 12. The structure of the electrical feedthrough 10 corresponds to the first example described in connection with FIG. 1. In contrast to the first example, the connection pin 20 is constructed and arranged in such a way that its side is not flush with the corresponding surface of the base 12. The overall thickness of the connection pin 20 is thus greater than the thickness of the base 12. It can be seen in FIG. 2 that the thickness of the cover material 24 is selected such that, in interaction with the fastening material 16, the first conductive material of the core 22 is still inaccessible from this side of the electrical feedthrough 10. Correspondingly, the fastening material 16 also contacts the cover material 24 directly in this example.

[0070] Where, as shown in this second embodiment, the cover material 24 protrudes beyond the surface of the substrate 12, a relatively large thickness for the cover material 24 is preferred. This thickness can be achieved, inter alia, by plating the core 22, or by bonding a thin plate, or by joining a thin plate or sheet to the core 22 using welding or brazing.

[0071] It is, of course, conceivable that one of the two sides of the connection pin 20 is arranged flush with the corresponding surface of the base 12, such that the connection pin 20 protrudes beyond the base 12 on only one of the two sides.

[0072] Fig. 3 shows a third example of the electrical feedthrough 10. As described in relation to the first embodiment of Fig. 1, the electrical feedthrough 10 has a base 12 having a through opening 14, in which a connection pin 20 is insulatively held via a fixing material 16.

[0073] 1, in addition, a further covering material 25 of a third conductive material is arranged on the second side of the core 22, so that both sides of the core 22 of the connection pin 20 are covered by the covering material 24, 25. Here, the further covering material 25 also directly contacts the fastening material 16, so that in this embodiment the first conductive material of the core 22 is completely enclosed within the electrical feedthrough 10. The third conductive material may be selected differently from the second conductive material or may be selected the same. Exemplarily, the same material is shown.

[0074] In the third embodiment of FIG. 3, the substrate 12 is furthermore constructed differently from the first two embodiments. The substrate 12 of the third embodiment has a reinforced region of width W, which borders the through-opening 14, in which the substrate 12 has an increased thickness d2. Outside the reinforced region the substrate 12 has a smaller thickness d1. This results in a particularly compact construction of the electrical feedthrough 10, which is particularly suitable for microbatteries. Nevertheless, the substrate 12 provides a high mechanical stability, which is also suitable for the construction of a metal-fixing material feedthrough as a compression seal. For this purpose, the width W is selected in such a way that the necessary pressing force can be generated for this purpose.

[0075] The configuration of the base body 12 with the reinforcing region can of course be combined with further embodiments, whereby, for example, unlike the illustration in FIG. 3, one or even both sides of the connection pin 20 may protrude beyond the surface of the base body 12 bordering the through opening 14 (see FIG. 7), or only the first side of the core 22 is covered by the cover material 24.

[0076] In Fig. 4, a fourth embodiment of the electrical feedthrough 10 is shown. As explained in relation to the first embodiment in Fig. 1, the electrical feedthrough 10 has a base body 12 with a through opening 14, in which a connection pin 20 is insulatively held via a fastening material 16. The core 22 of the connection pin 20 is provided on both sides with cover materials 24, 25 as shown in the third embodiment in Fig. 3, and in the illustrated embodiment, the side of the connection pin terminates flush with the surface of the base body 12 that contacts the through opening 14. As can be seen in this figure, in this embodiment, by way of example, another cover material 25 with a third conductive material is selected differently from the cover material 24 with the second conductive material.

[0077] The base body 12 of the fourth embodiment additionally comprises a flexible flange 30, via which the base body 12 can be joined to another element, for example another component of a housing. The flexible flange 30 is obtained, for example, by deformation of the base body 12 and has a transition area of ​​width W, in which the flat part of the base body 12 transitions to a glass sealing part having a thickness d2 that is greater than the thickness d1 of the flat part of the base body 12. The base body 12 is flexible and pliable in the transition area, so that the flexible flange 30 mechanically decouples this area from the through-opening 14. Correspondingly, stresses in the other parts of the housing are not transmitted to the fastening material 16. Furthermore, the thickness d2 in the glass sealing part can be freely selected within wide limits, so that the length of the glass sealing can be set independently of other dimensions of the base body 12 or of the housing with the base body.

[0078] Figure 5 shows a fifth embodiment of the electrical feedthrough 10, which is constructed similarly to the first embodiment of Figure 1. In contrast to the first embodiment, the core 22 of the contact pin 20 is fully coated, whereby all surfaces of the core 22 are covered by the covering material 24. Correspondingly, in particular, both side surfaces and the outer side surface of the core 22 are covered by the covering material 24.

[0079] In FIG. 6, a sixth embodiment of the electrical feedthrough 10 is shown, which is constructed similarly to the fourth embodiment of FIG. 4 and includes a flexible flange 30, the construction and function of which have already been described above. The core 22 of the contact pin 20 with the first conductive material is provided on both sides with cover materials 24, 25, as shown in the third embodiment of FIG. 4, which are exemplarily the same in this embodiment. In contrast to the fourth embodiment, the contact pin 20 is formed and arranged in such a way that its side surfaces are not flush with the corresponding surfaces of the base 12, but are arranged to protrude beyond them. Thus, the overall thickness of the contact pin 20 is greater than the thickness of the base 12 in the region of the feedthrough. It can be seen in FIG. 6 that the arrangement of the core 22 and the thickness of the cover material 24 with the second conductive material are selected such that, in interaction with the fastening material 16, the first conductive material of the core 22 is not accessible from the side of the electrical feedthrough 10. Correspondingly, also in this embodiment the fastening material 16 is in direct contact with the cover material 24. The cover material 24 is located here on a first side of the electrical feedthrough 10, which faces inwards when forming a casing. On the opposite second side of the feedthrough 10, which faces outwards when forming a housing, in the illustrated embodiment the first conductive material of the core 22 is accessible, since in this embodiment the fastening material 16 is not in direct contact with the cover material 25.

[0080] In a particularly advantageous embodiment of the sixth embodiment, the contact pin 20 has a core 22 made of ferritic steel as a first conductive material and, on both sides of the core 22, a cover material 24, 25 made of aluminum or an aluminum alloy as a second conductive material. The base body 12 is made of a steel having a higher coefficient of expansion than the material of the core 22, and in particular an austenitic steel is selected as the material for the base body 12. When selecting a low-melting-point bismuth-based fastening material 16, in combination with a base body 12 made of austenitic stainless steel, a hermetically sealed compression sealing can be provided.

[0081] When selecting the core 22 made of ferritic steel, the connection pin 20 is adapted to the requirements of the metal-fixing material feedthrough to be formed, taking into account its material properties, in particular with regard to its thermal expansion coefficient. In order to prevent or at least reduce corrosion of the connection pin 20, the core 22 is provided with a cover material 24 made of aluminum or an aluminum alloy on its side facing inwards when forming the housing, so that the core 22 is adapted to the material requirements of the storage cell, e.g. chemical resistance, electrochemical potential. If the core 22 is provided with a cover material 25 made of aluminum or an aluminum alloy on its side facing outwards when forming the housing, the connection pin 20 can be optimized, for example, for a simple and reliable connection to an electrical connection, for example brazing or welding.

[0082] In Fig. 7, a seventh embodiment of the electrical feedthrough 10 is shown, which is constructed similarly to the third embodiment of Fig. 3. The substrate 12 of the seventh embodiment likewise has a reinforcement region of width W, which borders the through opening 14 and in its interior the substrate 12 has an increased thickness d2. Outside the reinforcement region the substrate 12 has a smaller thickness d1. The advantages of such an embodiment have already been further explained above.

[0083] In a seventh embodiment, the base body 12 is provided with a load-relieving device 31, which in this embodiment is configured, for example, as a groove or recess, preferably as a surrounding groove or a surrounding recess. The groove of the load-relieving device 31 is exemplarily arranged on the second side of the electrical feedthrough 10, which faces outwards when forming the housing. Naturally, the groove may also be arranged on another side of the housing. Two grooves or recesses arranged on opposite sides of the base body can also be used as load-relieving device 31. Instead of a groove, a row of adjacent perforations may also be provided.

[0084] The load-relieving device 31 reduces the heat flow through the substrate 12, i.e. forms a thermal barrier, and / or reduces the mechanical load on the substrate 12 in the direction perpendicular to the axis of the contact pin 20, since the substrate 12 is deformable, preferably reversibly, in the direction perpendicular to the axis of the contact pin 20. This results in relatively small stresses being introduced into the fastening material 16, which act on it and thereby reduce compression thereon, and in particular no tensile stresses being introduced therein, thereby ensuring hermeticity of the feedthrough 10 under thermal and mechanical loads.

[0085] In contrast to the third embodiment, the connection pin 20 of the seventh embodiment is here constructed and arranged as in the sixth embodiment. In this embodiment too, the cover material 24 with the second conductive material is located on a first side of the electrical feedthrough 10, which faces inward when forming the housing, so that the core 22 of the connection pin 20 is not accessible from the inside. On the opposite, second side of the feedthrough 10, which faces outward when forming the housing, the first conductive material of the core 22 is also accessible in this embodiment, since in this embodiment the fastening material 16 does not directly contact the cover material 25. The advantageous material combinations mentioned in connection with the sixth embodiment can also be advantageous for the implementation of the feedthrough 10 with the load-relieving device 31.

[0086] Although the present invention has been described based on preferred embodiments, the present invention is not limited thereto, but rather may be modified in various ways, in particular by combining the features described based on different embodiments (e.g., the configuration of the base body (including stiffening devices, load relief devices, flexible flanges), the configuration and arrangement of the connecting pins, the selection of materials of the components, etc.) into another embodiment using the technical teachings of the present invention. [Explanation of symbols]

[0087] 10 Electrical Feedthrough 12 Base 14 Through opening 16 Fixed material 20 Connection pins 22 cores 24 Cover material 25 different cover materials 30 Flexible flange 31 Load reduction device d1 First thickness d2 Second thickness W width

Claims

1. An electrical feedthrough (10), in particular for an electrical storage device, comprising: The electrical feedthrough (10) includes a base (12) having a through opening (14), and a connection pin (20) disposed in the through opening (14), the connection pin (20) being held in the through opening (14) in an electrically insulated state via a fixing material (16). The contact pin (20) has a core (22) made of a first conductive material; At least on a first surface of the electrical feedthrough (10), a first side of the core (22) is covered by a cover material (24) made of a second conductive material; the connection pin (20) and the fastening material (16) are configured and arranged on the first surface of the electrical feedthrough (10) so that the first conductive material of the core (22) is inaccessible; Electrical feedthrough (10).

2. A second side of the core (22) opposite the first side is covered with another cover material (25) made of a third conductive material, the third conductive material being selected the same as or different from the second conductive material. The electrical feedthrough (10) of claim 1.

3. an outer surface of the core (22) facing the fixing material (16) is at least partially not covered with a cover material (24, 25) and is in direct contact with the fixing material (16); The electrical feedthrough (10) of claim 1.

4. The melting point of the fixing material (16) is selected to be lower than the melting point of any material of the contact pin (20). The electrical feedthrough (10) of claim 1.

5. The second conductive material and / or the third conductive material are attached to the side surface of the core (22) by plating, electroplating, coating, vapor deposition, welding or brazing. The electrical feedthrough (10) of claim 2.

6. The base (12) has a flexible flange (30). The electrical feedthrough (10) of claim 1.

7. The base (12) has a first thickness d outside the area of ​​the through opening (14). １ and has an increased second thickness d in the area adjacent to the through opening (14). ２ having The electrical feedthrough (10) of claim 1.

8. One or both sides of the connection pin (20) are arranged flush with the surface of the base (12). The electrical feedthrough (10) of claim 1.

9. One or both sides of the connection pin (20) are arranged to protrude beyond the surface of the base (12). The electrical feedthrough (10) of claim 1.

10. the material of the substrate (12) and / or the first conductive material of the core (22) of the contact pin (20) is selected from steel, in particular ferritic, austenitic or duplex steel, rust-free steel, stainless steel, iron-nickel alloy, iron-nickel-cobalt alloy, kovar, molybdenum or titanium; The electrical feedthrough (10) of claim 1.

11. the second conductive material and / or the third conductive material of the contact pin (20) is selected from aluminum, aluminum alloy, AlSiC, copper, copper alloy, molybdenum, nickel or nickel alloy, palladium, silver or gold; The electrical feedthrough (10) of claim 2.

12. the melting point of the second conductive material and / or the third conductive material is lower than the melting point of the first conductive material of the core (22) of the connection pin (20); The electrical feedthrough (10) of claim 2.

13. The fixing material (16) is a glass, a glass ceramic, or a ceramic, or the fixing material (16) includes a glass, a glass ceramic, or a ceramic. The electrical feedthrough (10) of claim 1.

14. The first coefficient of expansion of the substrate (12) is greater than the second coefficient of expansion of the fastening material (16), or the first coefficient of expansion of the substrate (12) and the second coefficient of expansion of the fastening material (16) are matched to each other. The electrical feedthrough (10) of claim 1.

15. The fastening material (16) and its connection with the wall of the through opening (14) and the connecting pin (20) are provided with a safety valve function via a preset pushing force, which is controlled by one or more of the following means: a. Selection of glass seal thickness; b. Selection of said fastening material (16); c. Selecting the percentage of bubbles in the fixing material (16); d. Structuring the surface of the fixing material (16) by setting the shape of the fixing material mould before glass sealing; e. Structuring the surface of the fixing material (16) in the glass seal; f. Laser processing the surface of the fixing material (16) after the glass sealing; g. The introduction of notches or tapers into said fastening material (16) on one or both sides, and / or h. Established by introducing a notch or taper into the contact pin (20) and / or the base (12); The electrical feedthrough (10) of claim 1.

16. The substrate (12) has a load-relieving device (31). The electrical feedthrough (10) of claim 1.

17. A housing provided with at least one electrical feedthrough (10) according to any one of claims 1 to 16. An electrical storage device, especially a battery or capacitor.

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