DE102021006016A1 - Round cell for an electrical energy store of a motor vehicle, in particular a motor vehicle - Google Patents

Abstract

The invention relates to a round cell (10) for an electrical energy store in a motor vehicle, having at least one electrode (12) which has an electrically conductive current collector (30) and a coating (34) made from active material and is wound up to form a coil (16). , and having at least one connection element (22) electrically connected to the electrode (12), via which electrical energy stored in the round cell (10) can be made available by the round cell (10), the current collector (30) having a coating ( 34) and a second sub-area (T2) adjoining the first sub-area (T1), which is free of the coating (34) and formed and thereby contains at least part of the active material and at least a part of the first portion (T1) in the longitudinal direction (18) of the coil (16) covering cover (36) forms, which with the connection element (22) electrically is connected and has passage openings (42) through which a gas (44) can flow.

Description

The invention relates to a round cell for an electrical energy store of a motor vehicle, in particular a motor vehicle, according to the preamble of patent claim 1.

Round cells of this type for electrical energy stores in motor vehicles, in particular motor vehicles, are already well known from the general state of the art. The respective round cell has at least one electrode, which includes an electrically conductive current collector, which is designed, for example, as an electrically conductive foil and is formed, for example, from a metallic material. The electrode also includes a coating formed of active material. The electrode is wound into a coil. The round cell also has a connection element, which is in particular formed separately from the electrode and is electrically connected to the electrode, which is for example at least partially arranged on an area surrounding the round cell or a cell housing of the round cell. The round cell, stored in the round cell, can provide electrical energy, in particular to the environment, via the connection element, which is also referred to as a terminal. In particular, the round cell can be electrically connected via the connection element to a further storage cell, external to the round cell, for storing electrical energy.

Furthermore, the DE 10 2019 116 969 A1 an energy storage device for a motor vehicle. Furthermore, the DE 10 2012 207 770 A1 to take a battery as known.

The object of the present invention is to improve a round cell of the type mentioned at the outset.

This problem is solved by a round cell with the features of patent claim 1 . Advantageous configurations with expedient developments of the invention are specified in the remaining claims.

In order to improve a round cell of the type specified in the preamble of patent claim 1, it is provided according to the invention that the current collector has a first partial area provided with the coating. In other words, the first partial area of the current collector is coated with the active material. The current collector has a second sub-area adjoining the first sub-area, in particular in the longitudinal direction of the coil, which is free of the coating and is therefore not coated. The longitudinal direction of the coil coincides, for example, with an imaginary coil axis around which the electrode is wound to form the coil.

The second partial area is deformed, in particular compressed, whereby the second partial area forms a cover covering at least part of the active material and at least part of the first partial area in the longitudinal direction of the roll. In particular, the cover runs at least partially in a plane which runs obliquely or perpendicularly to the longitudinal direction of the roll. The cover is electrically connected to the connection element, in particular by means of a connection element designed as a plate, for example, which is preferably designed separately from the connection element and separately from the electrode and is electrically connected to the connection element and the electrode, in particular the second partial area. In particular, the electrode is formed separately from the connection element and is electrically connected to the connection element.

• Das Entgasungsverhalten von Full-Tab- beziehungsweise Continuous-Tab-Zellen ist, falls keine entsprechenden Gegenmaßnahmen getroffen sind, prinzipbedingt sehr schlecht, da der Wickel auf seinen beiden, in Längsrichtung des Wickels einander gegenüberliegenden Seiten durch eine jeweilige Kontaktierung überdeckt und somit zumindest im Wesentlichen verschlossen wird. Eine der Kontaktierungen ist durch den genannten, zweiten Teilbereich gebildet. Eine zweite der Kontaktierung ist beispielsweise durch einen beschichtungsfreien, dritten Teilbereich eines zweiten Stromkollektors einer zweiten Elektrode gebildet.

The shaped, in particular compressed, second partial area and thus the cover also have passage openings, also referred to as gaps, through which a gas can flow. The gas is created, for example, during a thermal event in the round cell. In particular, the gas is formed from an, for example, liquid electrolyte of the round cell. The thermal event occurs, for example, when the round cell short-circuits. The through-openings (leakage points) now allow the gas produced in the coil to escape particularly well from the coil by the gas flowing through the through-openings. As a result, a particularly advantageous degassing behavior of the round cell configured as a full tab or continuous tab cell can be implemented. The invention is based in particular on the following findings:

• If no appropriate countermeasures are taken, the degassing behavior of full-tab or continuous-tab cells is inherently very poor, since the coil covers on its two opposite sides in the longitudinal direction of the coil by a respective contact and thus at least essentially is closed. One of the contacts is formed by the second partial area mentioned. A second contact is formed, for example, by a coating-free, third partial area of a second current collector of a second electrode.

On the one hand, the invention can ensure particularly reliable operation of the round cell on the other hand, aging problems can be avoided, any gas that is produced, in particular in the winding, can flow through the through-openings and thus flow out of the winding. This is particularly advantageous for very long round cells, ie for round cells that have a particularly large extent in the longitudinal direction of the roll. Furthermore, it is particularly advantageous for round cells with a high nickel content of, for example, more than 60%, and for applications which require the round cell to be charged particularly quickly. The apprenticeship positions are introduced, for example, by cutting into the uncoated, second partial area. The current collector and thus the partial areas are formed, for example, by a particularly metallic foil. In the wound-up state of the electrode and thus of the current collector, one or more total through-openings through which the gas can particularly advantageously escape from the coil results, particularly with a skillful choice of position, size and number of through-openings. The fact that the through-openings of the cover can, for example, in particular precisely form an overall through-opening means that the through-openings of the cover or of the second partial area, for example, at least partially overlap one another. In the non-formed state of the second portion and in the non-wound-up state of the electrode, the plurality of through-openings are formed in the second portion, which are spaced apart from one another.

In particular, the invention makes it possible for the gas produced in the event of a thermal event in the round cell, also referred to as thermal runaway or chain reaction, to be able to leave the coil quickly. Excessive bulging or enlarging of the winding and the resulting bursting of the round cell can be avoided. In addition, excessively rapid aging of the round cell, also simply referred to as a cell, can be avoided. If the gas cannot escape from the coil, for example, gas bubbles can form locally, which can lead to the electrodes detaching from the connecting element, for example. This can now be avoided by the invention.

For example, the current collector is formed from a metallic material such as aluminum or copper. The reshaping, in particular compression, of the uncoated, second partial area and the resulting formation of the cover enables a particularly large or full-surface, electrical and, for example, also thermal connection of the current collector to the connecting element designed, for example, as a cell conductor or also referred to as a cell conductor. It is also conceivable that the through-openings formed, for example, by cutting or cutting out and also referred to as holes, are arranged in the current collector in such a way that, when the electrode is wound up, they are arranged, for example, adjacent to one another but possibly separated by the active material and thus, for example, from the gas form channels through which it can flow, in particular through which it can flow in the longitudinal direction of the roll, through which the gas can escape. The gas can be conducted via the ducts, for example, to the passage openings in the cover, so that a particularly advantageous degassing behavior can be achieved.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing(s). The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

• 1 ausschnittsweise eine schematische Schnittansicht einer Rundzelle für einen elektrischen Energiespeicher eines Kraftfahrzeugs;
• 2 eine schematische Draufsicht eines Deckels der Rundzelle gemäß einer ersten Ausführungsform;
• 3 eine schematische Draufsicht des Deckels gemäß einer zweiten Ausführungsform;
• 4 eine schematische Draufsicht des Deckels gemäß einer dritten Ausführungsform;
• 5 eine schematische Draufsicht des Deckels gemäß einer vierten Ausführungsform;
• 6 eine schematische Draufsicht des Deckels gemäß einer fünften Ausführungsform;
• 7 eine schematische Draufsicht des Deckels gemäß einer sechsten Ausführungsform;
• 8 eine schematische Draufsicht des Deckels gemäß einer siebten Ausführungsform;
• 9 eine schematische Draufsicht des Deckels gemäß einer achten Ausführungsform;
• 10 eine schematische Draufsicht des Deckels gemäß einer neunten Ausführungsform;
• 11 eine schematische Draufsicht des Deckels gemäß einer zehnten Ausführungsform;
• 12 jeweils eine schematische Draufsicht des Deckels gemäß der vierten Ausführungsform und eine schematische Draufsicht eines Zellableiters der Rundzelle gemäß einer ersten Ausführungsform;
• 13 jeweils eine schematische Draufsicht des Deckels gemäß 12 und eine schematische Draufsicht des Zellableiters gemäß einer zweiten Ausführungsform; und
• 14 ausschnittsweise eine schematische Schnittansicht einer Elektrode der Rundzelle in einem nicht aufgewickelten Zustand der Elektrode.

The drawing shows in:

• 1 a detail of a schematic sectional view of a round cell for an electrical energy store of a motor vehicle;
• 2 a schematic plan view of a cover of the round cell according to a first embodiment;
• 3 a schematic plan view of the lid according to a second embodiment;
• 4 a schematic plan view of the lid according to a third embodiment;
• 5 a schematic plan view of the cover according to a fourth embodiment;
• 6 a schematic top view of the cover according to a fifth embodiment;
• 7 a schematic top view of the cover according to a sixth embodiment;
• 8th a schematic plan view of the cover according to a seventh embodiment;
• 9 a schematic plan view of the cover according to an eighth embodiment;
• 10 a schematic top view of the cover according to a ninth embodiment;
• 11 a schematic top view of the cover according to a tenth embodiment;
• 12 in each case a schematic top view of the cover according to the fourth embodiment and a schematic top view of a cell conductor of the round cell according to a first embodiment;
• 13 each according to a schematic plan view of the lid 12 and a schematic plan view of the cell conductor according to a second embodiment; and
• 14 a detail of a schematic sectional view of an electrode of the round cell in a non-wound state of the electrode.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a schematic sectional view of a round cell 10, also referred to simply as a cell, for an electrical energy store of a motor vehicle, in particular a motor vehicle. Electrical energy can be stored, in particular electrochemically, by means of or in the round cell 10 . Round cell 10 has two electrodes 12 and 14, which are wound together to form a coil 16, also known as an electrode coil, in particular about an imaginary coil axis that coincides with a longitudinal direction of coil 16, with the longitudinal direction of coil 16 in 1 is illustrated by a double arrow 18 .

The round cell 10 has a cell housing 20, also referred to as a cup. The winding 16 and thus the electrodes 12 and 14 are arranged in the cell housing 20 . The round cell 10 also has a connection element 22, which is formed separately from the electrodes 12 and 14 and is also referred to as a terminal, which is arranged at least partially outside of the cell housing 20 and thus on an area 24 of the cell housing 20 and thus of the round cell 10 as a whole. The connection element 22 formed separately from the electrodes 12 and 14 is electrically connected to a first cell connector 26 which is formed separately from the connection element 22 and separately from the electrodes 12 and 14 and is electrically connected to the electrode 12 . As a result, the connection element 22 is electrically connected to the electrode 12 via the cell connector 26 . The cell connector 26 is, for example, a first plate, which is also referred to as the first connecting plate. The cell connector 26 is a first connection element. The electrode 14 is assigned, for example, a second connecting element 28 which is formed separately from the connecting element 22 , separately from the electrodes 12 and 14 and separately from the cell housing 20 . The connecting element 28 is, for example, electrically connected to the electrode 14 and, for example, electrically to the cell housing 20, so that the electrode 14 is electrically connected to the cell housing 20, for example, via the connecting element 28. The connection element 22 embodied separately from the cell housing 22 is electrically insulated from the cell housing 20 .

The round cell 10 can provide the electrical energy stored in it via the connection element 22 . Furthermore, electrical energy can be stored in the round cell 10 via the connection element 22 . In particular, the round cell 10 can be electrically connected via the connection element 22 to a further storage cell, in particular a further round cell, which is external to the round cell 10 and is therefore arranged in the surrounding area 24 .

Especially good in combination with 14 it can be seen from the example of the electrode 12 that the respective electrode 12, 14 has a respective current collector 30, 32 which is electrically conductive, that is to say electrically conductive. The respective current collector 30, 32 is formed, for example, from an electrically conductive, metallic material. For example, the current collector 30 is made of copper. In this case, for example, the cell connector 26 is also made of copper. The current collector 32 is formed of aluminum, for example. Thus, for example, the connecting element 28 is also made of aluminum. In particular, the connecting element 28 is designed as a second plate, ie as a second connecting plate. Furthermore, at least the electrode 12 and/or the electrode 14 has a coating 34 formed from active material.

In order to be able to achieve a particularly advantageous degassing behavior and thus particularly safe operation of the round cell and to be able to avoid excessively rapid aging of the round cell 10, the current collector 30 and/or 32 is provided with the coating 34 in a first partial area T1 and thus with the Active material coated. A second sub-area T2 of the current collector 30 and/or 32 adjoining the first sub-area T1 is uncoated and therefore free of the coating 34. The respective second sub-area T2 is compressed and thus formed, whereby the respective sub-area T2 has a respective cover 36, 38 forms. At least a respective part of the active material or the coating 34 and the first partial region T1 is covered by the cover 36 in the longitudinal direction of the coil 16 . The lid 36 covers at least the respective parts in a first direction running parallel to the longitudinal direction of the coil 16 and in the process towards the connection element 22 . The cover 38 covers the respective parts in a second direction running parallel to the longitudinal direction of the coil 16 and opposite the first direction, and in the process toward the connecting element 28 or toward a base 40 of the cell housing 20 opposite the connecting element 22 in the longitudinal direction of the round cell 10.

Especially good in combination with 14 it can be seen that the respective, uncoated, second partial area T2 and thus the respective cover 36, 38 has a plurality of through-openings 42, in particular spaced apart from one another and also referred to as voids, which are connected by an in 1 Gas 44 shown schematically can be flowed through. The gas 44 is created, for example, during a thermal event in the round cell 10 and/or as the operating or service life of the round cell 10 increases. As a result, an uncontrolled bursting of the round cell 10 can be avoided, so that the round cell 10 can be operated particularly safely. In addition, excessively rapid aging of the round cell 10 can be avoided.

It can be seen that the cell connector 26, also referred to as a cell conductor, is electrically connected to the second partial area T2 of the current collector 30. For example, the cell conductor is connected, in particular electrically, to the partial area T2 of the current collector 30 and/or to the connection element 22 by welding. The connector 28 is electrically connected to the portion T2 of the current collector 32 . For example, the connecting element 28 is connected, in particular electrically, to the partial region T2 of the current collector 32 and/or to the cell housing 20, in particular to the base 40, by welding. Out 14 it can be seen that the voids, also referred to as holes, for example, are produced, for example, by cutting, in particular by cutting out. In particular, the voids are or will be located at specific positions. For example, the voids are produced by a laser, by means of which the respective, uncoated partial area T2 is trimmed in order to thereby produce the voids. A position and/or size, in particular width, of the respective void is determined, for example, by calculation and/or experimentally.

2 until 11 show a respective, schematic plan view of a respective embodiment, for example, of the compressed and thereby deformed subregion T2 of the current collector 30 and thus of the cover 36. In the wound state of the electrodes 12 and 14, the voids (through-openings 42) in the cover 36 result in flow-through openings, and therefore total through-openings , through which the gas can flow, as a result of which the gas can escape from the coil 16 in a particularly advantageous manner. A variant is advantageous in which, for example, there is at least or exactly one empty space above each winding of the winding 16, so that, as in 11 is illustrated, only a small azimuthal flow or movement of the gas 44 is required to escape from the coil 16.

12 and 13 show in a respective schematic plan view a respective embodiment, for example of the cell conductor 26 designed as a contacting plate. It can be seen that the cell conductor also advantageously has at least one or more further through-openings 46, through which the gas 44, which flows through the through-openings 42, flows can. If, for example, the respective empty space in the z-direction, i.e. in the longitudinal direction of the coil 16, is sufficiently dimensioned, the respective through-opening 46 in the contacting plate or in the cell conductor (cell connector 26) can only extend over part of the respective empty space in the coil 16. the gas 44 can then move or flow within the respective void to the through-opening 46 .

Reference List

10

round cell

12

electrode

14

electrode

16

wrap

18

double arrow

20

cell case

22

connection element

24

Surroundings

26

cell connector

28

fastener

30

current collector

32

current collector

34

coating

36

lid

38

lid

40

floor

42

passage opening

44

gas

46

passage opening

T1

first section

T2

second section

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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

• DE 102019116969 A1 [0003]
• DE 102012207770 A1 [0003]

Claims (3)

Round cell (10) for an electrical energy store of a motor vehicle, with at least one electrode (12) which has an electrically conductive current collector (30) and a coating (34) made of active material and is wound up to form a coil (16), and with at least a connection element (22) electrically connected to the electrode (12), via which electrical energy stored in the round cell (10) can be made available by the round cell (10), characterized in that the current collector (30) has a coating (34 ) provided, first sub-area (T1) and in a second sub-area (T2) adjoining the first sub-area (T1), which is free of the coating (34) and formed and thereby at least one part of the active material and at least one Part of the first portion (T1) in the longitudinal direction (18) of the winding (16) covering cover (36) forms, which with the connection element (22) electrically ver is connected and has through openings (42) through which a gas (44) can flow. Round cell (10) after claim 1 , characterized in that at least one of the through-openings (42) has an angular, in particular rectangular, cross-section through which the gas (44) can flow. Round cell (10) after claim 1 or 2 , characterized in that at least one of the passage openings (42) has an oval or round cross section through which the gas (44) can flow.

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