DE102020207893A1 - Conductor element of an electrode arrangement from a plurality of electrochemical cells - Google Patents

Abstract

Conductor element of an electrode arrangement of a plurality of electrochemical cells, comprising a first electrically conductive area and second electrically conductive areas, the second electrically conductive areas each comprising at least two electrically conductive finger-like elements, one electrode of the electrochemical cells of the electrode arrangement, in particular an anode or cathode, one of the second areas can be electrically connected to at least two of the finger-like elements, the first electrically conductive area being electrically connected to the second electrically conductive areas and the electrically conductive connection between the first area and the second area being at least partially electrically non-conductive is interrupted, wherein the conductor element is made of a nickel-plated steel.

Description

The invention is based on a diverter element of an electrode arrangement of a plurality of electrochemical cells, a method for producing a battery system with the diverter element and a use of the diverter element in electrical energy stores according to the preamble of the independent claims.

State of the art

The publication published on November 29, 2018 EP 3631882 of the applicant is the starting point of the present invention and discloses a diverter element of an electrode arrangement of a plurality of electrochemical cells.

Disclosure of the invention

Advantages of the invention

The procedure according to the invention includes that the conductor element comprises a first electrically conductive area and second electrically conductive areas, the second electrically conductive areas each comprising at least two electrically conductive finger-like elements, with one electrode of the electrochemical cells of the electrode arrangement, in particular an anode or cathode , one of the second areas can be electrically connected to at least two of the finger-like elements, the first electrically conductive area being electrically connected to the second electrically conductive areas and the electrically conductive connection between the first area and the second areas being at least partially electrically non-conductive interrupted . Furthermore, according to the invention, the diverter element is made from nickel-plated steel.

As a result, electrochemical cells can be connected to one another in an electrically conductive manner and electrical current, in particular a nominal current, can flow between the first region and the second regions without significant voltage losses.

At this point it should be noted that the nickel-plated steel is in particular a high-purity, nickel-plated steel, which is also known under the name Hilumin.

Such a nickel-plated steel has a comparably high corrosion resistance and a comparatively good electrical conductivity. Furthermore, a triggering speed of the fuse can be increased noticeably in this way; Compared to pure nickel, for example, the release time is reduced by around 40 percent. Such a more rapid triggering, on the one hand, significantly reduces the risk of thermal propagation, which means that overall security can be increased. On the other hand, the material thickness of the arrester element could also be increased due to the more rapid tripping; Compared to pure nickel, the material thickness could be increased from 0.2 mm to 0.3 mm, for example. Arrester elements with a higher material thickness are overall mechanically more robust against vibrations and shock loads. Furthermore, arrester elements with a higher material thickness are comparably easier to weld and can thereby form more robust and reliable connections.

Furthermore, nickel-plated steel is also comparably inexpensive; roughly compared to nickel.

Further advantageous embodiments are the subject of the subclaims.

Melting areas are formed by the electrically non-conductive interruptions, as a result of which the current-carrying capacity of the electrically conductive connection between the first area and the second areas is reduced.

Advantageously, the melting areas can be reliably produced with the aid of common stamping and bending processes and have a sufficiently high resistance to mechanical loads, for example vibrations, and temperature changes.

The electrical connection between the first area and one of the second areas is interrupted when a threshold value of the current flowing between the first area and the second area is exceeded. As a result of the melting areas, a current-carrying capacity of the electrical connection between the first area and the second area is reduced, so that a fuse is formed by means of the electrical connection in the form of a web. The interruption of the electrical connection can take place independently, for example in the event of a fault, by melting the melting areas of the electrical connection between the first area and the second area.

In this way, for example, at least one short-circuited electrochemical cell can be disconnected from a circuit during an abnormal operating state, which reliably prevents further heating.

As a result, a chain reaction with a high level of reliability is essentially prevented compared to the prior art.

By suitably selecting a geometry for the melting areas, the current-carrying capacity can be adapted to a particular application, that is to say the threshold value of the maximum permissible current flowing between the first area and the second area can be defined.

The finger-like elements have at least partially third electrically conductive areas, which are electrically connected to the second electrically conductive areas.

The third electrically conductive areas advantageously enable process-reliable contacting of the second electrically conductive areas with electrochemical cells, in particular electrodes of the electrochemical cells, by means of the third electrically conductive areas. The third electrically conductive areas can advantageously be used for a resistance welding process.

The melting areas are advantageously between 0.3 and 2 mm, in particular 0.5 mm, wide and / or between 1 and 5 mm, in particular 1 mm, long.

The melting areas are advantageously between 0.3 and 2 mm, in particular 0.75 mm, wide and / or between 0.5 and 5 mm, in particular 1 mm, long.

The conductor element advantageously has a material thickness between 0.1 and 5 mm, in particular between 0.2 and 0.5 mm.

The third electrically conductive areas advantageously have a convex or concave shape. As a result, a sufficiently small contact area for a welding current is achieved in the resistance welding process. In one embodiment, the third regions comprise a projection that is substantially deformed back during resistance welding.

• - Herstellung eines Ableiterelements durch:
  • - Walzen eines elektrisch leitfähigen Rohlings aus vernickeltem Stahl, wodurch ein erster Bereich des Ableiterelements geformt wird;
  • - Stanzen des gewalzten ersten Bereichs, wodurch zweite Bereiche, insbesondere zwei elektrisch leitfähige fingerartige Elemente umfassend, und/oder eine Mehrzahl von elektrisch nichtleitenden Unterbrechungen geformt werden;
• - Einsetzen der Mehrzahl von Zellen in eine Zellhalterung, insbesondere mit abwechselnder Anordnung von Elektroden der Zellen;
• - Einsetzen einer Mehrzahl von Ableiterelementen, um mechanisches Kontaktieren mit den Elektroden;
• - Widerstandsschweißen mittels zumindest zwei die leitfähigen fingerartigen Elemente jeweils eines der zweiten Bereiche zum Kontaktieren der fingerartigen Elemente mit den Elektroden der Zellen zu einer Serienschaltung und/oder Parallelschaltung der Mehrzahl von Zellen;
• - Elektrisches Kontaktieren der Ableiterelemente mit Anschlusspolen des Batteriesystems.

A method according to the invention for producing a battery system with a plurality of electrochemical cells and an arrester element comprises the following steps:

• - Production of an arrester element by:
  • Rolling an electrically conductive blank made of nickel-plated steel, whereby a first region of the diverter element is formed;
  • - Punching the rolled first area, whereby second areas, in particular comprising two electrically conductive finger-like elements, and / or a plurality of electrically non-conductive interruptions are formed;
• - Insertion of the plurality of cells in a cell holder, in particular with an alternating arrangement of electrodes of the cells;
• Inserting a plurality of diverter elements in order to mechanically contact the electrodes;
• Resistance welding by means of at least two conductive finger-like elements each one of the second areas for contacting the finger-like elements with the electrodes of the cells to form a series connection and / or parallel connection of the plurality of cells;
• - Electrical contact between the arrester elements and the connection poles of the battery system.

In an alternative embodiment, the punched second areas are bent in such a way that third areas electrically connected to the second areas are formed and at least two third areas of the conductive finger-like elements each form one of the second areas of the finger-like elements with the electrodes of the cells by means of resistance welding Series connection and / or parallel connection of the plurality of cells are contacted.

The battery system with a plurality of electrochemical cells and the arrester element according to the invention can advantageously be produced by means of conventional production methods. A highly automated manufacturing process is also possible.

An adaptation of a series connection and / or a parallel connection of the plurality of cells is possible by a simple geometric change in the arrester element.

The arrester element according to the invention is advantageously used in electrical energy storage devices for electric vehicles, hybrid vehicles, plug-in hybrid vehicles, pedelecs, or e-bikes, for portable devices for telecommunication or data processing, for electrical hand tools or kitchen appliances, as well as in stationary storage devices for storing, in particular, regeneratively obtained electrical energy Uses energy.

Figure list

Embodiments of the invention are shown in the drawing and explained in more detail in the description below.

• 1 ein Batteriesystem mit einer ersten Ausführungsform eines erfindungsgemäßen Ableiterelements; und
• 2 eine schematische Detaildarstellung der ersten Ausführungsform des Ableiterelements; und
• 3 eine zweite Ausführungsform eines erfindungsgemäßen Ableiterelements; und
• 4 eine schematische Darstellung eines Aufschmelzverhaltens der ersten Ausführungsform des erfindungsgemäßen Ableiterelements.

Show it:

• 1 a battery system with a first embodiment of a diverter element according to the invention; and
• 2 a schematic detailed representation of the first embodiment of the diverter element; and
• 3 a second embodiment of a diverter element according to the invention; and
• 4th a schematic representation of a melting behavior of the first embodiment of the diverter element according to the invention.

Detailed description of the exemplary embodiments

The same reference symbols denote the same device components in all figures.

1 shows a battery system with a first embodiment of a diverter element according to the invention. The battery system 100 comprises a plurality of electrochemical cells 109 , 110 , 111 , 112 , 113 which in a cell holder 106 are used, an arrester element 101 with a first electrically conductive area 101 (1) , second electrically conductive areas 101 (2) and third electrically conductive areas 101 (3) . The second areas 101 (2) comprise, in the embodiment shown, first electrically conductive fingers 101 (2a) and second electrically conductive fingers 101 (2b) . A first third area 101 (3a) is on the first fingers 101 (2a) as well as a second third area 101 (3b) on the second fingers 101 (2b) pronounced. The second areas also include 101 (2) a stretch area 105 , causing, for example, movements of the electrochemical cells in the cell holder 106 can be compensated and / or a spatial distance between the diverter element 101 and the cell holder 106 and / or a housing for the electrochemical cells 109 , 110 , 111 , 112 , 113 is ensured.

The first area 101 (1) is electrically conductive to the second areas 101 (2) connected, with electrically non-conductive interruptions, for example in the form of recesses 132 , are provided, which reduce the current-carrying capacity of the electrically conductive connections. In the embodiment shown, the recesses are 132 punched out, so electrically non-conductive. Through the cutouts 132 become first, second and third melting ranges 130 (1) , 130 (2) , 130 (3) as well as other melting ranges 131 (1) , 131 (2) educated.

In the embodiment shown, the first are cells 109 , the third cell 111 and the fifth cell 113 of the kind in the cell holder 106 inserted that the cathode towards the cell holder 106 is aligned. The second cell 110 and the fourth cell 112 are in kind in the cell holder 106 inserted that the anode towards the cell holder 106 is aligned.

The first and second fingers 101 (2a) , 101 (2b) are electrical with the electrodes of the electrochemical cells 109 , 110 , 111 , 112 , 113 connected, preferably a connection made by a resistance welding process.

In the embodiment shown, the second and fourth are cells 110 , 112 or the first, third and fifth cells 109 , 111 , 113 connected in parallel. Through the arrester element 101 are the second and fourth cells 110 , 112 in series with the first, third and fifth cells 109 , 111 , 113 electrically connected.

Typical nominal currents flow through the melting areas without significant voltage losses 130 (1) , 130 (2) , 130 (3) or. 131 (1) , 131 (2) . If a short circuit occurs in one of the cells 109 , 110 , 111 , 112 , 113 on, the first, second and third melting areas heat up 130 (1) , 130 (2) , 130 (3) or the first and second melting ranges 131 (1) , 131 (2) so strong within a short time that these melt and the respective cell 109 , 110 , 111 , 112 , 113 from the first area 101 (1) of the arrester element 101 is electrically disconnected.

This separation takes place in a serial direction. An electrical monitoring of voltage levels on each individual arrester element 101 is carried out by a battery management system via measuring lines connected to it, which are welded to one side end of each arrester element. The separation in the serial direction has significant advantages over a separation in the parallel direction according to the prior art, since this has the consequence that all cells that are "behind" the separated area are also separated with respect to the measuring line, whereby their state can no longer be monitored by the battery management system.

2 shows a first schematic detailed representation of the first embodiment of the arrester element. An electrochemical cell 410 is by means of a second area 401 (2) with an arrester element 401 electrically contacted. By means of third areas 401 (3a) and 401 (3b) becomes the arrester element 401 with one electrode of the cell 410 Electromechanically connected, for example by means of a connection made by resistance welding.

During resistance welding it can happen that a significant part of an electrical current is drawn from the electrode of the cell 410 via the arrester element 401 by a second finger of the second area 401 (2) flows and from there again over a first finger of the second area 401 (2) flows back into the electrode. This unwanted electrical current flow is in 2 by the reference number 441 shown. In the case of a geometry, this unavoidable boundary condition must be the fingers of the second area 401 (2) of the arrester element 401 must be taken into account so that adjacent melting areas are not damaged due to heating or heat input with a reduced current-carrying capacity.

In the embodiment shown, a length is 442 the finger, for example between 3 and 10 millimeters, of the second area 401 (2) selected in such a way that an electrical resistance is set in such a way that an electrical current flowing during resistance welding 440 essentially entirely from the third area 401 (3b) of the second finger of the second area 401 (2) over the electrode of the cell 410 to the third area 401 (3a) of the first finger of the second area 401 (2) of the arrester element 401 flows.

A further increase in the electrical resistance of the first and second fingers of the second area 401 (2) of the arrester element 401 can through a suitable choice of geometries 443 and 445 causing an undesirable flow of current 441 is further reduced and damage caused by resistance welding during a manufacturing process is essentially eliminated.

3 shows a second embodiment of a diverter element according to the invention in the form of a cell connector 501 for electrochemical cells. Using the cell connector 501 fifteen cells can be electrically connected to one another in parallel, which form a so-called row, and two of these rows can be connected in series.

The cell connector 501 includes a first area 501 (1) , second areas 501 (2) , the second areas 501 (2) first fingers 501 (2a) and second fingers 501 (2b) include. The first fingers also include 501 (2a) first third areas 501 (3a) and the second fingers 501 (2b) second third areas 501 (3b) .

Electrically conductive connections between the first area 501 (1) and the second areas 501 (2) comprise a plurality of electrically non-conductive interruptions, for example in the form of cutouts 532a , 532b , thereby advantageously melting ranges according to the invention 530a , 530b , 530c or. 530d , 530e be shaped.

The three melting ranges 530a , 530b , 530c or the two melting ranges 530d , 530e are advantageously 0.5 mm or 0.75 mm wide in the embodiment shown. The cell connector 501 has a material thickness of essentially 0.3 mm. This results in a total cross-sectional area of 0.45 mm ^{2 for} both the three melting areas 530a , 530b , 530c , as well as for the two melting ranges 530d , 530e .

The in 3 Cell connector shown 501 is produced, for example, by rolling an electrically conductive blank, punching the rolled blank and then bending it.

Becomes the cell connector 501 Used in an electrical energy storage system, a short circuit in electrochemical cells leads to the melting areas 530a , 530b , 530c of the cell connector 501 in the corresponding cells are quickly heated to temperatures above a melting temperature of the material. The melting areas 530a , 530b , 530c In practice, currents of different sizes flow through them, which advantageously results in a cascading effect.

With three melting ranges 530a , 530b , 530c this means that initially a melting range of the melting ranges 530a , 530b , 530c melts, whereby the current is distributed to the remaining melting areas. In practice, a higher current flows through one of the two webs than through the other melting area, so that in turn one of the two melting areas first melts. Thus, after a certain period of time, the full current only flows through one of the three melting areas 530a , 530b , 530c whereby this also melts. This creates the electrical connection between the first area 501 (1) and second area 501 (2) electrically separated. Due to the melting ranges, quick release times can be achieved compared to the prior art, in particular below 5 seconds.

4th shows a schematic representation of a melting behavior of the first embodiment of the arrester element according to the invention. A diverter element 601 includes a first area 601 (1) that with second areas 601 (2) is electrically connected, the electrically conductive connection being at least partially interrupted in an electrically non-conductive manner, for example by cutouts 632a , 632b . Through melting areas 630a , 630b , 630c is a current carrying capacity of the electrical connection between the first area 601 (1) and the second area 601 (2) reduced, so that a fuse is formed by means of the electrical connection in the form of a web. The electrical connection between the first area 601 (1) and one of the second areas 601 (2) is exceeded when a threshold value of the between the first range 601 (1) and the second area 601 (2) flowing stream interrupted. In the event of a fault, the electrical connection is interrupted by melting the melting areas 630a , 630b , 630c the electrical connection between the first 601 (1) Area and the second area 601 (2) independent.
The arrester element is before time t0 601 in normal operation with a typical nominal electrical current across all melting ranges 603a , 630b , 630c can flow.

Due to a fault in the cell at time t0, for example in the event of a short circuit in the cell, the cell and the second area heat up 601 (2) of the arrester element 601 In a short time, strongly and due to the abnormal electric current flowing above the rated current, the first melting range melts 630c at a point in time t1.

From the point in time t1, the abnormal current therefore only flows through the melting areas 630a and 630b . Due to the smaller cross-section of the melting range 630b compared to the melting range 630a the melting range melts 630b at a point in time t2, wherein it is to be expected in particular that a difference between the time periods t2 and t1 is smaller than a difference between the time periods t1 and t0.

From time t2, the entire abnormal current now flows through the melting range 630a , which melts at a point in time t3, wherein it is to be expected in particular that a difference between the time spans t3 and t2 is smaller than a difference between the time spans t2 and t1.

From the point in time t3, the cell is off the diverter element 601 irreversibly separated, whereby a safe state is achieved and propagation due to the heating by the discharge currents to other cells is reliably prevented.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 3631882 [0002]

Claims (9)

Conductor element (101, 401, 501, 601) of an electrode arrangement of a plurality of electrochemical cells (109, 110, 111, 112, 113, 410), comprising a first electrically conductive area (101 (1), 501 (1), 601 (1)) and second electrically conductive areas (101 (2), 401 (2), 501 (2), 601 (2)), the second electrically conductive areas (101 (2), 401 (2), 501 ( 2), 601 (2)) each comprise at least two electrically conductive finger-like elements (101 (2a), 101 (2b), 501 (2a), 501 (2b), 601 (2a), 601 (2b)), wherein one electrode each of the electrochemical cells (109, 110, 111, 112, 113, 410) of the electrode arrangement, in particular an anode or cathode, with at least two of the finger-like elements (101 (2a), 101 (2b), 501 (2a), 501 (2b), 601 (2a), 601 (2b)) one of the second areas (101 (2), 401 (2), 501 (2), 601 (2)) can be electrically connected, the first electrically conductive area (101 (1), 601 (1)) with the second electrically conductive areas (101 (2), 401 (2), 501 (2), 601 (2) ) is electrically connected and the electrically conductive connection between the first area (101 (1), 501 (1), 601 (1)) and the second area (101 (2), 401 (2), 501 (2), 601 (2)) is at least partially electrically non-conductive interrupted, characterized in that the diverter element is formed from a nickel-plated steel. Conductor element (101, 401, 501, 601) of an electrode arrangement according to Claim 1 , characterized in that melting areas (130 (1), 130 (2), 130 (3)) are formed by the electrically non-conductive interruption (132,532a, 532b, 632a, 632b), which a current-carrying capacity of the electrically conductive connection between the first area (101 (1), 501 (1), 601 (1)) and the second areas (101 (2), 401 (2), 501 (2), 601 (2)). Conductor element (101, 401, 501, 601) of an electrode arrangement according to one of the preceding claims, characterized in that the electrical connection between the first area (101 (1), 501 (1), 601 (1)) and one of the second areas (101 (2), 401 (2), 501 (2), 601 (2)) when a threshold value between the first area (101 (1), 501 (1), 601 (1)) and the second is exceeded Area (101 (2), 401 (2), 501 (2), 601 (2)) flowing current is interrupted. Conductor element (101, 401, 501, 601) of an electrode arrangement according to one of the preceding claims, characterized in that the finger-like elements (101 (2a), 101 (2b), 501 (2a), 501 (2b), 601 (2a) , 601 (2b)) have third electrically conductive areas (101 (3)) which are electrically connected to the second electrically conductive areas (101 (2), 401 (2), 501 (2), 601 (2)). Conductor element (101, 401, 501, 601) of an electrode arrangement according to one of the preceding claims, characterized in that the melting areas (130 (1), 130 (2), 130 (3), 131 (1), 131 (2)) between 0.3 and 2 millimeters wide and / or between 1 and 5 millimeters long. Conductor element (101, 401, 501, 601) of an electrode arrangement according to one of the preceding claims, characterized in that the conductor element (101, 401, 501, 601) has a material thickness between 0.1 and 5 millimeters, in particular between 0.2 and 0 , 5 millimeters. Conductor element (101, 401, 501, 601) of an electrode arrangement according to one of the preceding claims, characterized in that the third electrically conductive areas (101 (3)) have a convex or concave shape. Method for producing a battery system with a plurality of electrochemical cells (109, 110, 111, 112, 113, 410) and a diverter element (101, 401, 501, 601) according to one of the Claims 1 until 7th comprising the following steps: - Production of a conductor element (101, 401, 501, 601) by ◯ rolling an electrically conductive blank made of nickel-plated steel, whereby a first area (101 (1), 601 (1)) of the conductor element (101, 401, 501, 601) is molded; ◯ Punching the rolled first area (101 (1), 501 (1), 601 (1)), creating second areas (101 (2), 401 (2), 501 (2), 601 (2)), in particular two electrically conductive finger-like elements (101 (2a), 101 (2b), 501 (2a), 501 (2b), 601 (2a), 601 (2b)) comprising, and / or a plurality of electrically non-conductive interruptions (132,532a , 532b, 632a, 632b); - Insertion of the plurality of cells (109, 110, 111, 112, 113, 410) in a cell holder, in particular with an alternating arrangement of electrodes of the cells (109, 110, 111, 112, 113, 410); - Insertion of a plurality of conductor elements (101, 401, 501, 601) and mechanical contact with the electrodes; - Resistance welding by means of at least two conductive finger-like elements (101 (2a), 101 (2b), 501 (2a), 501 (2b), 601 (2a), 601 (2b)) each one of the second areas (101 (2), 401 (2), 501 (2), 601 (2)) and / or at least two third, electrically connected to the second regions (101 (2), 401 (2), 501 (2), 601 (2)) Areas (101 (3), 101 (3a), 101 (3b)) for electrical contact with the finger-like elements (101 (2a), 101 (2b), 501 (2a), 501 (2b), 601 (2a), 601 (2b)) with the electrodes of the cells (109, 110, 111, 112, 113, 410) to form a series connection and / or parallel connection of the plurality of cells (109, 110, 111, 112, 113, 410); - Electrical contacting of the arrester elements (101, 401, 501, 601) with connection poles of the battery system (100). Use of a diverter element (101, 401, 501, 601) according to one of the Claims 1 until 8th in electrical energy storage devices for electric vehicles, hybrid vehicles, plug-in hybrid vehicles, pedelecs or e-bikes, for portable devices for telecommunications or data processing, for electrical hand tools or kitchen appliances, as well as in stationary storage devices for storing electrical energy obtained in particular from renewable sources.

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