DE102017221026A1 - Battery cell, battery module containing them, as well as their use - Google Patents

Abstract

The invention relates to a battery cell, in particular a lithium-ion battery cell, having a battery cell housing on which a first and a second contact surface for electrically contacting the battery cell are formed, wherein the first contact surface has a first contact surface and the second contact surface has a second contact surface, and wherein the first and / or second contact surface (28, 29, 60, 64) at least two, in particular a plurality of elevations (40) is formed.

Description

The present invention relates to a battery cell, a battery module containing this and their use according to the preamble of the independent claims.

State of the art

Conventional batteries contain a plurality of battery cells, which are electrically contacted with each other. In the case of typical batteries for end consumers, this contacting takes place, for example, via terminal battery terminals on corresponding battery cells. In addition, there is also the possibility of contacting by means of gold or nickel spring contacts. In the field of high-voltage batteries, for example, for automotive application, contacting takes place via so-called busbars or via wired solutions. Furthermore, there is the possibility of electrical contacting by means of cell connectors. These contacting means are connected, for example, via a suitable screw connection or by welding to the corresponding terminals of the battery cells.

In addition, battery cells are known in which the battery cell housing itself or in each case a half-shell of the battery cell housing serves as a contact surface for making electrical contact with the battery cell. This makes it possible to dispense with additionally pronounced battery terminals. Such battery cells are for example the DE 10 2014 204 245 A1 refer to.

Furthermore, from the WO 92/07390 known to accomplish the contact between two battery cells to the effect that raised electrode terminals of a battery cell engages in a mounted on the battery cell bottom of another battery cell recesses and in this way an electrical contact between the raised battery cell terminals and mounted within the recesses electrical contacts of an adjacent battery cell arises ,

Disclosure of the invention

According to the invention, a battery cell, a battery module containing these, and their use with the characterizing features of the independent claims are provided.

Advantages of the invention

In this case, the battery cell according to the invention has a battery cell housing which has a first and a second contact surface for electrically contacting the battery cell, wherein the first contact surface has a first contacting surface and the second contact surface has a second contacting surface. The first and / or second contacting surface forms at least two, preferably a plurality of elevations.

The particular advantage of this measure is that in this way a contact resistance occurring when contacting the contact surface can be minimized. This is based on the knowledge that the contact resistance is influenced by a large number of factors. These include, for example, the surface quality of the first or second contacting surface, the hardness of the material provided for the first and second contact surfaces, the possible presence of oxidic impurities on the surface of the first and second contact surfaces and a possible contact pressure with which a contact the first or second contacting surface is pressed. It has been shown that, in particular, the height of the contact pressure or the pressing force with which a contact is pressed onto the first or second contacting surface has a significant influence on the height of the contact resistance occurring between the contact and the first and second contacting area , Furthermore, there is a relationship between the size of the contact surface occurring between a contact and the first or second contacting surface and the contact pressure realized thereby. The smaller the contact area is selected, the higher the contact pressure between the contact and the respective contacting surface becomes higher for a given contact pressure. With the provision of at least two in particular a plurality of elevations, which forms the surface of the first and second contacting surface, a sufficiently high contact pressure is achieved with sufficient contact area at the same time.

Further advantageous embodiments of the present invention are the subject of the dependent claims.

For example, the elevations are mirror-symmetrical or rotationally symmetrical. The advantage of this embodiment is that elevations in symmetrical shape show a lower contact resistance than, for example, strip-shaped or flat contact surfaces. The same applies to elevations that are edge-free and corner-free and show a lower contact resistance compared to square or angular elevations. This effect is already noticeable when cutting profiles produced by imaginary sections perpendicular to the first or second contacting surface, in particular by a central axis of a survey in question, at least partially or some of them show a curve-free or corner-free course.

According to a particularly advantageous embodiment of the present invention, the battery cell housing is designed in the form of two mutually electrically insulated half-shells. In this case, a first half-shell of the battery cell housing forms the first contact surface and a second half-shell of the battery cell housing forms the second contact surface. In this case, elevations are located on the first and / or second half-shell of the battery cell housing, in particular only on the surface of the first half-shell of the battery cell housing.

It is particularly advantageous if the first half shell of the battery cell housing is made of a nickel-plated steel and the second half shell of the battery cell housing is made of aluminum. For example, Hilumin® can be used as a nickel-plated steel.

Furthermore, it is advantageous if the elevations of the first or second contacting surface show a semicircular or half-ellipsoidal shape and in their highest area a contact surface with a diameter of <150 μm. In this way, when applying a suitable contact pressure, a particularly low contact resistance can be achieved. This is enhanced if, in addition, the highest area of corresponding elevations is provided, for example, with a silver coating, or the elevations are made of silver or a silver alloy.

According to a further advantageous embodiment of the present invention, the battery cell is designed for example as a so-called round cell with a cylindrical housing. In this case, a first contact surface of the battery cell is formed by the bottom of the cylindrical battery cell case and a second contact surface of the battery cell by a battery cell terminal formed on a lid of the battery cell case. In this case, elevations are provided either on the first or the second contact surface, preferably on the second contact surface.

The present invention is also a battery module containing at least two battery cells of the type described above. It is particularly advantageous if the battery module additionally has a bracing device, are clamped to each other via the at least two battery cells of the battery module, wherein the battery cells by the tension a force is exerted which causes elevations on a contact surface of the one battery cell to be pressed onto a contact surface of an adjacent second battery cell. In this way, the contact resistance between the two battery cells is significantly reduced.

The battery cell according to the invention or a battery module containing it can be used in a particularly advantageous manner in vehicle applications such as in electric or hybrid vehicles, in mobile devices of telecommunications or data processing, in electric hand tools or in stationary energy storage, in particular for the storage of regeneratively generated electrical energy.

In this case, the battery cell according to the invention or the module containing it may be a rechargeable battery. The battery cell itself can be based on lithium-ion technology or on a battery cell with solid electrolyte, for example. A polymer or ceramic electrolyte.

list of figures

• 1: eine schematische Darstellung einer perspektivische Ansicht eines erfindungsgemäßen Batteriemoduls enthaltend erfindungsgemäße Batteriezellen
• 2: eine perspektivische Darstellung eines Ausschnitts des in 1 abgebildeten Batteriemoduls,
• 3: eine perspektivische Darstellung eines Verbundes erfindungsgemäßer Batteriezellen in einer ersten Darstellung,
• 4: eine perspektivische Darstellung eines Verbundes erfindungsgemäßer Batteriezellen in einer zweiten Darstellung,
• 5: eine perspektivische Darstellung eines Bildausschnitts des in 3 dargestellten Verbundes erfindungsgemäßer Batteriezellen,
• 6: eine schematische Aufsicht auf eine Großfläche einer erfindungsgemäßen Batteriezelle gemäß einer ersten Ausführungsform der vorliegenden Erfindung,
• 7: eine schematische Aufsicht auf die Großfläche einer erfindungsgemäßen Batteriezelle gemäß einer zweiten Ausführungsform,
• 8: eine schematische Aufsicht auf die Großfläche einer erfindungsgemäßen Batteriezelle gemäß einer dritten Ausführungsform,
• 9: eine schematische Schnittdarstellung durch ein erfindungsgemäßes Batteriemodul gemäß einer zweiten Ausführungsform der vorliegenden Erfindung,
• 10: eine schematische Darstellung einer perspektivischen Ansicht einer erfindungsgemäßen Batteriezelle gemäß einer vierten Ausführungsform der vorliegenden Erfindung und
• 11: eine schematische Schnittdarstellung eines erfindungsgemäßen Batteriemoduls gemäß einer dritten Ausführungsform.

Advantageous embodiments of the present invention are illustrated in the drawing and explained in more detail in the following description of the figures. It shows:

• 1 : a schematic representation of a perspective view of a battery module according to the invention containing battery cells according to the invention
• 2 : a perspective view of a section of the in 1 pictured battery module,
• 3 FIG. 2 is a perspective view of a composite of battery cells according to the invention in a first representation, FIG.
• 4 : a perspective view of a composite of battery cells according to the invention in a second illustration,
• 5 : a perspective view of an image section of the in 3 shown composite of battery cells according to the invention,
• 6 FIG. 2 shows a schematic plan view of a large area of a battery cell according to the invention in accordance with a first embodiment of the present invention, FIG.
• 7 FIG. 2: a schematic plan view of the large area of a battery cell according to the invention, according to a second embodiment, FIG.
• 8th FIG. 2: a schematic plan view of the large area of a battery cell according to the invention, according to a third embodiment, FIG.
• 9 FIG. 2 shows a schematic sectional illustration through a battery module according to the invention according to a second embodiment of the present invention, FIG.
• 10 a schematic representation of a perspective view of a battery cell according to the invention according to a fourth embodiment of the present invention and
• 11 : A schematic sectional view of a battery module according to the invention according to a third embodiment.

This in 1 illustrated embodiment shows a battery module according to the invention 1 , This includes a plurality of battery cells 2 , In particular, it is provided that the battery cells 2 rechargeable lithium-ion battery cells are. The battery cells 2 are preferably formed such that the outer sides of each first and a second contact surfaces 3 . 4 for electrical contacting of the battery cell 2 formed. In this way are the battery cells 2 of the battery module 1 serially electrically connecting with each other via the first and second contact surfaces formed by the outer sides 3 . 4 electrically interconnected. Thereby the battery cells become 2 for example, by a plurality of frame elements 7 . 8th . 12 fixed.

The battery module 1 covers at one end 10 a first frame element 7 , which is a module end plate of the battery module 1 forms. At this first frame element 7 is a first battery cell 2 arranged, wherein the first frame element 7 the first battery cell 2 for example, partially encloses. A border 25 an outer shell 26 the battery cell 2 forms an investment area with which the respective battery cell 2 of the battery module 1 each on a frame element 7 . 8th . 12 is applied.

On the first frame element 7 with the battery cell halfway inside 2 is a third frame element 12 arranged, wherein the third frame element 12 the other half of the battery cell 2 framed. The third frame element 12 also framed one to the first battery cell 2 adjacently arranged further battery cell 2 also in half. In this way, close several third frame elements 12 and other battery cells 2 to each other, with a last battery cell 2 at the end 11 a sequence 9 the battery cells 2 from a second frame element 8th partially enclosed.

The frame elements 7 . 8th . 12 are each preferably via fixing 13 releasably connected together. As fixing elements 13 In particular, not shown latching hooks are provided which in in 1 not explicitly illustrated corresponding detents intervene. In this way, the first frame element 7 about the other third frame elements 12 with the second frame element 8th releasably connected.

The frame elements 7 . 8th . 12 are at the in 1 illustrated Ausführungsbespiel a battery module according to the invention 1 additionally as a cooling device for the battery cells 2 formed and have for this purpose each one of a coolant flow-through cooling channel 16 on.

In addition, it is provided that the frame elements 7 . 8th . 12 each in 1 not explicitly shown contacting elements, wherein the contacting elements each a battery cell 2 of the battery module 1 Battery cell parameters, in particular a battery cell voltage and / or battery cell currents and / or battery cell temperatures detect. In addition, the frame elements have 7 . 8th . 12 at least one in each case 1 not explicitly illustrated connection element, which is electrically conductively connected to contacting elements. The respective connection element of a frame element 7 . 8th . 12 is doing one with the frame elements 7 . 8th . 12 arranged circuit board 18 preferably electrically conductively connected. Advantageously, the printed circuit board comprises 18 Components of a battery management system, in particular at least one cell monitoring unit (Cell Supervising Cirquit CSC).

The embodiment of the battery cells according to the invention 2 allows an interconnection of several such battery cells 2 by juxtaposing them with their first and second contact surfaces, which is exemplified in FIG 2 is shown.

In 2 are the battery cells 2 thereby connected in series by a series, wherein advantageously for the interconnection of the battery cells 2 no cell connectors are required, which contributes to weight reduction. The illustrated battery cells 2 are each by contacting a first housing half shell 28 the housing of the battery cell 2 with a second half shell 29 an adjacent battery cell 2 electrically connected in series.

The battery cells shown in FIG 2 each comprise an electrode arrangement 27 with a cathode 32 and an anode 33 , The electrode arrangement 27 is from a first half shell 28 and a second half shell 29 the battery cell 2 enclosed. The first half shell 28 and the second half shell 29 are connected via a connection area electrically non-conductive with each other. In the connection region is at least one insulator element 30 arranged, such that the first half-shell 28 against the second half shell 29 is electrically isolated. Furthermore, the cathode 32 for example via a first electrically conductive connecting element 31 with the first half shell 28 connected and the anode 33 for example via a second electrically conductive connecting element 31 ' with the second half shell 29 ,

On the surface of the second half shell 29 , which also acts as a second contact surface, are surveys 40 provided, the electrical contacting of the battery cell 2 with a neighboring further battery cell 2 serve. Embodiments of the survey 40 are described in the following 3 to 8th shown in more detail. Here, the same reference numerals designate the same component components as in FIGS 1 and 2 ,

In 3 are exemplary three battery cells 2 illustrated, each first contact surfaces in the form of first half-shells 28 and second contact surfaces in the form of second half shells 29 respectively. Here are on the large surface of the respective second half shells 29 surveys 40 executed, the electrical contacting of a first battery cell 2 with an adjacent second battery cell 2 serve. This is also in 4 to recognize. 5 clarifies one in 3 marked image section that with A is designated.

As in particular in 5 recognizable, are the surveys 40 essentially corner- and katenfrei executed in their form. Furthermore, the survey shows 40 in 5 a semi-ellipsoidal course. The surveys 40 For example, by a corresponding electrodeposition of metallic material in particular on the surface of the second half-shell 29 be generated or by a deformation of the material of the second half-shell 29 to form a survey 40 , The assessment 40 may be formed for example by silver or a silver alloy or the second half-shell 29 is in the area of the survey 40 provided with a silver coating. While the first housing half shell 28 for example, made of a nickel-plated steel such as Hilumin® is, for example, the second half-shell 29 made of aluminum.

Alternatively, there is the possibility of the in the 2 to 5 shown embodiments of battery cells according to the survey 40 instead of the second half shell 29 on the large surface of the first half-shells 28 provided. A combination of both measures is conceivable, in both half shells 28 . 29 each surveys 40 are provided, which correspond to each other substantially at least in height.

In the 6 to 8th are different ways of arranging surveys 40 on the large surface of the first or second half-shell 28 . 29 the battery cell according to the invention 1 , The arrangement of the surveys 40 Here's the example of one with surveys 40 provided first half shell 28 clarified. On the one hand there is the possibility, as in 6 represented, the surveys 40 essentially statistically on the large area of the first and second half shells 28 . 29 to arrange. Furthermore, there is the possibility, as in the 7 or 8th represented, the surveys 40 about a vertical central axis of the large area of the first and second half-shell 28 . 29 to arrange around rotationally symmetrical. The embodiments shown show in practical tests a particularly low electrical contact resistance when contacting the survey 40 with the half-shells 28 . 29 neighboring battery cells 2 ,

In 9 is schematically a battery module 1 shown according to another embodiment. Here, the same reference numerals designate the same component components as in FIGS 1 to 8th ,

The battery module 1 includes, for example, a battery module housing 50 , a plurality of parallel or series electrically connected battery cells 2 protects against external influences. Inside the battery module housing 50 there is a bracing device 52 , for example, the battery cells 2 of the battery module 1 pressed against each other. The pressing device 52 exerts an axial pressing force F _axially on the battery _cells 2 , from whose direction in 9 is indicated by a corresponding arrow. By the pressure exerted on the battery cells 2 becomes the contact resistance of the battery cells 2 at the elevations 40 minimized. At the same time, the battery cells overheat 2 by an increased contact resistance and thus the risk of a "thermal runaways" met.

In 10 a battery cell according to the invention is shown according to a second embodiment of the present invention. The battery cell 2 is in this case designed as a so-called round cell, for example as a so-called 18650 round cell. This has a cylindrical battery cell housing, this being a first cylindrical, open-topped housing element 60 and a lid that closes this 62 has, on which a battery terminal 64 is provided. In this case, the first housing part forms 60 a first contact surface of the battery cell 2 off and the battery terminal 64 on the lid 62 a second contact surface. At the in 10 example shown is, for example, on the bottom surface of the first housing part 60 a plurality of surveys 40 intended. Alternatively or additionally, it is also possible to use the battery terminal 64 with elevations 40 to provide.

Will battery cells of in 10 shown form converted into a corresponding battery module, so there is an exemplary Arrangement of the battery cells 2 as they are in 11 is shown. In this case, the same reference numerals designate the same component components as in the preceding figures.

The battery module 1 comprises a plurality of receiving spaces in which cylindrically shaped round cells in the form of battery cells 2 are located. These show, connected to the respective battery cell terminal 64 , corresponding surveys 40 , Alternatively, however, it is also possible the surveys 40 on the underside of the battery cell case 60 provided.

This in 11 shown battery module 1 further includes, for example, coolant channels 8th , which can be flowed through by a coolant. The battery module 1 further includes on the back wall 25 on supporting elements 22 arranged spring elements 21 , which as a Verpress unit 52 serve.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102014204245 A1 [0003]
• WO 9207390 [0004]

Claims (14)

Battery cell, in particular lithium ion battery cell, with a battery cell housing, on which a first and a second contact surface for electrically contacting the battery cell is formed, wherein the first contact surface has a first contacting surface and the second contact surface, a second contacting surface, characterized in that the first and / or second contacting surface (28, 29, 60, 64) at least two, in particular a plurality of elevations (40) is formed. Battery cell after Claim 1 , characterized in that the elevations (40) have a mirror-symmetrical or rotationally symmetrical shape. Battery cell after Claim 1 or 2 , characterized in that at least some vertical sectional profiles of the first and / or second contacting surface (28, 29, 60, 64) show a continuous and corner-free course in the region of the elevations (4). Battery cell after one of Claims 1 to 3 , characterized in that the elevations (40) are executed corners and edges. Battery cell according to one of the preceding claims, characterized in that the battery cell housing of two electrically insulated half shells (28, 29) is executed, wherein a first half-shell (28) of the battery cell housing forms the first contact surface and a second half-shell (29) of the battery cell housing a second contact surface of the battery cell housing, and that the first and / or second half-shell (28, 29) of the battery cell housing has projections (40). Battery cell after Claim 5 , characterized in that a first half-shell (28) of the battery cell housing is made of a nickel-plated steel and / or the second half-shell (29) of the battery cell housing made of aluminum. Battery cell according to one of the preceding claims, characterized in that a plurality of projections (40) is provided, which are in particular designed symmetrically to a vertical center axis of the contacting surface. Battery cell according to one of the preceding claims, characterized in that the elevations (40) show a semicircular or half-ellipsoidal profile in a vertical section. Battery cell according to one of the preceding claims, characterized in that the elevations (40), at their highest point have a contact surface for an electrical contact with a diameter of more than 150 microns. Battery cell according to one of the preceding claims, characterized in that a contact surface formed at the highest point of the elevations (40) has a coating of silver. Battery cell according to one of the preceding claims, characterized in that the battery cell housing is cylindrical and the first contact surface is formed by a bottom (60) of the cylindrical housing and the second contact surface by a formed on the top (62) of the cylindrical battery cell housing battery terminal (64 ). Battery module containing at least two battery cells according to one of the preceding claims. Battery module after Claim 11 , characterized in that a bracing device (52) is provided, via which at least two battery cells (2) of the battery module are clamped together so that elevations (40) on one of the contact surfaces of a battery cell (2) on a contact surface of an adjacent second battery cell (2) is pressed. Use of a battery cell according to one of Claims 1 to 11 or a battery module according to one of Claims 12 to 13 in electric or hybrid vehicles, in mobile devices for telecommunications or data processing and in electrical hand tools and electrical energy storage stationary type for storing in particular regeneratively generated electrical energy.

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