DE102016205160A1 - battery cell - Google Patents

Abstract

The invention relates to a battery cell (2) comprising a cell housing (3) in which an electrode unit (10) is arranged, the electrode unit (10) having an anode (21) connected to a negative terminal (11) and one having a positive terminal In this case, the electrode unit (10) is designed as an electrode stack which has a plurality of layers of the anode (21) and a plurality of layers of the cathode (22) which are arranged in a stacking direction (x ) are stacked on top of each other, and the cell casing (3) is prismatic, with all surfaces of the cell casing (3) parallel or perpendicular to the stacking direction (x), and the cell casing (3) has a first casing part (61) supporting the negative terminal (11) and a second housing part (62) forming the positive terminal (12).

Description

The invention relates to a battery cell comprising a cell housing in which an electrode unit is arranged, wherein the electrode unit has an anode connected to a negative terminal and a cathode connected to a positive terminal.

State of the art

Electrical energy can be stored by means of batteries. Batteries convert chemical reaction energy into electrical energy. Here, a distinction is made between primary batteries and secondary batteries. Primary batteries are only functional once, while secondary batteries, also referred to as accumulators, are rechargeable. In particular, so-called lithium-ion battery cells are used in an accumulator. These are characterized among other things by high energy densities, thermal stability and extremely low self-discharge.

Lithium-ion battery cells have a positive electrode, also referred to as a cathode, and a negative electrode, also referred to as an anode. The cathode and the anode each comprise a current conductor, on which an active material is applied. The electrodes of the battery cell are formed like a foil and, with the interposition of a separator, which separates the anode from the cathode, wound into an electrode winding or stacked to form an electrode stack with a plurality of electrode layers. The two electrodes of the electrode unit are electrically connected to poles of the battery cell, which are also referred to as terminals. The electrodes and separator are surrounded by a generally liquid electrolyte.

A generic battery cell comprising an electrode unit with an anode and a cathode, for example, from DE 10 2012 223 796 A1 known. The battery cell in this case has a cell housing, which is made for example of a metal and prismatic, in particular cuboid, configured. The anode and the cathode are connected by means of collectors with terminals which are arranged outside the cell housing.

From the US 2012/0276437 For example, a battery cell is known which has an electrode stack which is arranged in a metallic housing. The housing in this case comprises two housing parts, which are electrically isolated from each other by a seal. The anode and the cathode of the electrode stack in this case have contact lugs, which are electrically connected to one of the housing parts. The housing parts thus form the terminals of the battery cell.

Also from the JP 2011-154784 For example, a battery cell is known which has an electrode stack arranged in a metallic housing. The housing also comprises two housing parts, which form the terminals of the battery cell.

Disclosure of the invention

A battery cell, in particular a lithium-ion battery cell, is proposed which comprises a cell housing in which an electrode unit is arranged. In this case, the electrode unit has an anode, which is electrically connected to a negative terminal of the battery cell, and a cathode, which is electrically connected to a positive terminal of the battery cell.

According to the invention, the electrode unit is designed as an electrode stack which has a plurality of layers of the anode and a plurality of layers of the cathode. The layers of the anode and the layers of the cathode are stacked in a stacking direction. The cell housing is prismatic, with all surfaces of the cell housing parallel or perpendicular to the stacking direction. The cell housing has a first housing part, which forms the negative terminal, and a second housing part, which forms the positive terminal.

In this context, a prism is a body whose sides have the same length and whose base is a polygon. The cell housing of the battery cell has the shape of a straight prism, wherein the base of the prism is perpendicular to the stacking direction of the electrode unit.

According to an advantageous embodiment of the invention, the first housing part, which forms the negative terminal, and the second housing part, which forms the positive terminal, electrically conductive, in particular metallic, executed. In this case, the first housing part and the second housing part by a rotating insulator are electrically isolated from each other.

Advantageously, the insulator projects into an attachment element, which has a cooling channel and / or a voltage tap and / or a sensor. Thus, the attachment is firmly connected to the cell housing of the battery cell.

According to an advantageous development of the invention, the anode has contact lugs, and the cathode has contact lugs. The contact lugs of the anode and the contact lugs protrude the cathode on opposite sides of the electrode unit designed as an electrode stack out.

Preferably, the contact lugs of the anode are connected directly to the first housing part. Likewise, the contact lugs of the cathode are preferably connected directly to the second housing part. Preferably, therefore, an additional collector which connects the contact lugs with the housing parts, not needed and not used.

According to an advantageous embodiment of the invention, the contact lugs of the anode are materially connected to the first housing part. Likewise, the contact lugs of the cathode are advantageously materially connected to the second housing part.

According to a further advantageous embodiment of the invention, the contact lugs of the anode are positively connected to the first housing part. Likewise, the contact lugs of the cathode are advantageously connected positively to the second housing part.

According to an advantageous development of the invention, a base area of the prismatic cell housing that is perpendicular to the stacking direction has a hexagonal shape.

According to a further advantageous embodiment of the invention, the first housing part has a convex bulge. Likewise, the second housing part has a convex bulge. By the convex bulges electrical contacting of the terminals of the battery cell forming housing parts is facilitated.

A battery cell according to the invention advantageously finds use in an electric vehicle (EV), in a hybrid vehicle (HEV), in a plug-in hybrid vehicle (PHEV), in a stationary battery, in particular for network stabilization in households, in a battery in a marine application, For example, in shipbuilding or jet skis, or in a battery in an aeronautical application, especially in aircraft. Other applications are conceivable.

Advantages of the invention

The inventive design of the battery cell, the electrochemically usable volume within the cell housing is advantageously increased. This is especially true when the tabs of the electrodes are directly connected to the housing parts, which additional collectors for connecting the electrodes to the terminals are not required. Saved volume can be used for example for an external sensor or for a cooling system. Furthermore, a connection of several battery cells with each other is possible with effective utilization of an available volume. The arrangement of the contact lugs of the electrodes on opposite sides of the current density is homogenized within the electrode unit, resulting in an extended life of the battery cell.

Brief description of the drawings

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below.

Show it:

1 a schematic sectional view of a battery cell,

2 a schematic, partially transparent representation of a battery cell according to a first embodiment,

3 a schematic representation of a blank of an electrode for the battery cell 2 .

4 a schematic, partially transparent representation of a battery cell according to a second embodiment,

5 a schematic representation of the blank of an electrode for the battery cell 4 .

6 a schematic, partially transparent representation of a battery cell according to a third embodiment,

7 a schematic, partially transparent representation of a battery cell according to a fourth embodiment,

8th a schematic sectional view of a battery cell with a possible connection of contact lugs with a housing part,

9 1 is a schematic sectional view of a battery cell with another possible connection of contact lugs with a housing part,

10 FIG. 2 a schematic sectional view of a battery cell with a further possible connection of contact lugs to a housing part, FIG.

11 a schematic sectional view of a battery cell with another possible connection of tabs with a housing part,

12 1 is a schematic sectional view of a battery cell with yet another possible connection of contact lugs with a housing part,

13 a schematic, partially transparent detail view of the battery cell 2 with an attachment and

14 a schematic sectional view of the battery cell 13 ,

Embodiments of the invention

In the following description of the embodiments of the invention, the same or similar elements are denoted by the same reference numerals, wherein a repeated description of these elements is dispensed with in individual cases. The figures illustrate the subject matter of the invention only schematically.

1 shows a schematic sectional view of a battery cell 2 , The battery cell 2 includes a cell housing 3 , which is carried out electrically conductive. The cell case 3 has a first housing part 61 and a second housing part 62 on, which by a circulating insulator 50 are electrically isolated from each other. The housing parts are made of a metal, for example made of aluminum. The first housing part 61 forms a negative terminal 11 , and the second housing part 62 forms a positive terminal 12 , About the terminals 11 . 12 can one from the battery cell 2 provided voltage can be tapped. Furthermore, the battery cell 2 over the terminals 11 . 12 also be loaded.

Inside the cell case 3 the battery cell 2 is an electrode unit designed as an electrode stack 10 arranged, which two electrodes, namely an anode 21 and a cathode 22 , having. The anode 21 and the cathode 22 are each made like a foil and each have several layers. The layers of the anode 21 and the layers of the cathode 22 are each one layer of a film-like separator under interposition 18 Stacked in a stacking direction x.

The cell case 3 is prismatic. The cell case 3 has a base and a top surface, which are congruent, and which are oriented parallel to each other and at right angles to the stacking direction x. Furthermore, the cell housing 3 a plurality of side surfaces which are oriented parallel to the stacking direction x.

The anode 21 includes an anodic active material 41 , which is designed like a film. The anode 21 further includes a current collector 31 , which is also formed like a foil and electrically conductive. The anodic active material 41 is present on both sides of the current collector 31 the anode 21 arranged and connected to this. The cathode 22 comprises a cathodic active material 42 , which is designed like a film. The cathode 22 further includes a current collector 32 , which is also formed like a foil and electrically conductive. The cathodic active material 42 is present on both sides of the current collector 32 the cathode 22 arranged and connected to this.

The current collector 31 the layers of the anode 21 each have a contact lug in one end region 35 the anode 21 on which from the electrode unit 10 sticking out. The current collector 32 the layers of the cathode 22 each have a contact lug in one end region 36 the cathode 22 on which from the electrode unit 10 sticking out. The contact flags 35 the anode 21 and the contact flags 36 the cathode 22 protrude in a longitudinal direction y on opposite sides of the electrode unit 10 out. The longitudinal direction y is at right angles to the stacking direction x. A transverse direction z, which is also used below, is at right angles to the stacking direction x and at right angles to the longitudinal direction y.

The contact flags 35 the anode 21 are to the first housing part 61 led and at a negative connection point 71 associated with this. Thus, the negative terminal 11 the battery cell 2 electrically with the anode 21 connected. The contact flags 36 the cathode 22 are to the second housing part 62 guided and at a positive connection point 72 associated with this. Thus, the positive terminal 12 the battery cell 2 electrically with the cathode 22 connected.

2 shows a schematic, partially transparent representation of a battery cell 2 according to a first embodiment. The base of the cell case 3 has a hexagonal shape. The cell case 3 has two side surfaces which are oriented at right angles to the longitudinal direction y. The cell case 3 also has two side surfaces which are oriented at right angles to the transverse direction z. Furthermore, the cell housing 3 two side surfaces which are oriented at an angle of the present 45 ° inclined to the longitudinal direction y and to the transverse direction z. On one of these two side surfaces is the negative connection point 71 at which the contact flags 35 the anode 21 with the first housing part 61 are connected. At the other of these two side areas is the positive connection point 72 at which the contact flags 36 the cathode 22 with the second housing part 62 are connected.

3 shows a schematic representation of a blank of an electrode, in this case a cathode 22 , for the battery cell 2 out 2 , On the foil-like current conductor 32 the cathode 22 is the cathodic active material 42 applied, wherein each side a strip of Stromableiters 32 the cathode 22 free from the cathodic active material 42 is. The individual layers of the cathode 22 are punched in the present case at an angle of 45 °. One corner of the punched out layers protrudes into the free strip of the current conductor 32 the cathode 22 into it and forms there the contact lug 36 the cathode 22 , At the opposite corner a recess is provided. The layers of the anode 21 are punched out analogously. Subsequently, the layers of the anode 21 and the layers of the cathode 22 and interlayer of layers of the separator 18 stacked so that the tabs 36 the cathode 22 over the recesses of the anode 21 lie, and that the contact flags 35 the anode 21 over the recesses of the cathode 22 lie. The contact flags 35 . 36 can, if necessary, be extended by welding on additional pieces.

4 shows a schematic, partially transparent representation of a battery cell 2 according to a second embodiment. At two opposite sides of the cell housing in the longitudinal direction y 3 in each case a convex bulge is provided. In the area of one of these convex bulges is the negative attachment site 71 , on which the contact flags 35 the anode 21 with the first housing part 61 are connected. In the area of the other convex bulge is the positive attachment site 72 , on which the contact flags 36 the cathode 22 with the second housing part 62 are connected. The two convex recesses are diagonally opposite, ie in the longitudinal direction y and in the transverse direction z opposite, on the cell housing 3 intended.

5 shows a schematic representation of the blank of an electrode, in this case a cathode 22 , for the battery cell 2 out 4 , On the foil-like current conductor 32 the cathode 22 is the cathodic active material 42 applied, wherein each side a strip of Stromableiters 32 the cathode 22 free from the cathodic active material 42 is. The individual layers of the cathode 22 are punched out so that a part of the punched out layers in the free strips of the current collector 32 the cathode 22 protrudes into it and there the contact flag 36 the cathode 22 forms. The layers of the anode 21 are punched out analogously. Subsequently, the layers of the anode 21 and the layers of the cathode 22 and interlayer of layers of the separator 18 stacked so that the tabs 36 the cathode 22 diagonally offset to the contact lugs 35 the anode 21 lie. The contact flags 35 . 36 can, if necessary, be extended by welding on additional pieces.

6 shows a schematic, partially transparent representation of a battery cell 2 according to a third embodiment, which is substantially similar to the second embodiment. In contrast to the battery cell 2 According to the second embodiment are in the battery cell 2 according to the third embodiment, the convex protrusions on the cell housing 3 arranged in the longitudinal direction y opposite and in the transverse direction z in alignment.

7 shows a schematic, partially transparent representation of a battery cell 2 according to a fourth embodiment, which is substantially similar to the second embodiment. In contrast to the battery cell 2 According to the second embodiment are in the battery cell 2 According to the fourth embodiment, the convex protrusions on the cell housing 3 arranged in the longitudinal direction y opposite and centrally aligned in the transverse direction z.

8th shows a schematic sectional view of a battery cell 2 with a possible connection of contact flags 35 the anode 21 with the first housing part 61 , The second housing part 62 as well as the insulator 50 are not shown. The contact flags 35 the anode 21 are from the electrode unit 10 first in the stacking direction x and in the longitudinal direction y to the base of the cell housing 3 guided. From there, the contact flags run 35 the anode 21 in the longitudinal direction y parallel to the base surface to a side surface of the cell housing 3 , Next run the tabs 35 the anode 21 in the stacking direction x away from the base.

8a shows a first step to connect the tabs 35 the anode 21 with the first housing part 61 , In the said side surface a convex projection is provided, to which the tabs 35 the anode 21 are guided. The contact flags 35 the anode 21 be with the convex projection, which is the negative attachment point 71 represents in the present case materially connected, for example by means of ultrasonic welding, resistance welding or laser welding. Alternatively, the contact flags 35 the anode 21 also positively, for example by means of clinching or crimping, with the convex projection, which is the negative connection point 71 represents connected.

In a next step, which in 8b is the negative connection point 71 with the associated contact flags 35 the anode 21 in the cell case 3 bent over.

9 shows a schematic sectional view of a battery cell 2 with another possible connection of contact flags 35 the anode 21 with the first housing part 61 , The contact flags 35 the anode 21 are from the electrode unit 10 first in the stacking direction x and in the longitudinal direction y to the base of the cell housing 3 guided. The contact flags 35 the anode 21 are at the negative connection point 71 , which is located on the base, directly with the first housing part 61 connected, preferably cohesively. The insulator 50 , which is the first housing part 61 from the second housing part 62 isolated, it is partially inside and partly outside of the cell housing 3 and is by means of housing connectors 56 with the housing parts 61 . 62 connected. In the case connector 56 it is for example an adhesive.

10 shows a schematic sectional view of a battery cell 2 with another possible connection of contact lugs 35 the anode 21 with the first housing part 61 , The contact flags 35 the anode 21 are from the electrode unit 10 first in the stacking direction x and in the longitudinal direction y to the base of the cell housing 3 guided. From there, the contact flags run 35 the anode 21 in the longitudinal direction y parallel to the base surface to a side surface of the cell housing 3 , The contact flags 35 the anode 21 are at the negative connection point 71 , which is located on this side surface, directly to the first housing part 61 connected, preferably cohesively. The insulator 50 , which is the first housing part 61 from the second housing part 62 isolated, is similar to in 9 shown trained and with the housing parts 61 . 62 connected.

11 shows a schematic sectional view of a battery cell 2 with still a possible connection of contact flags 35 the anode 21 with the first housing part 61 , The contact flags 35 the anode 21 are from the electrode unit 10 first in the stacking direction x and in the longitudinal direction y to a connection element 54 guided, which with the first housing part 61 connected is. The contact flags 35 the anode 21 are at the negative connection point 71 , which are connected to the connection element 54 located with the attachment element 54 preferably connected positively. Thus, the tabs are 35 the anode 21 indirectly with the first housing part 61 connected. The insulator 50 , which is the first housing part 61 from the second housing part 62 isolated, is similar to in 9 shown trained and with the housing parts 61 . 62 connected.

12 shows a schematic sectional view of a battery cell 2 with yet another possible connection of contact lugs 35 the anode 21 with the first housing part 61 , The contact flags 35 the anode 21 are from the electrode unit 10 first in the longitudinal direction y to a collector 52 guided and connected with this. The collector 52 is at the negative connection point 71 , which are located on the first housing part 61 located, with the first housing part 61 connected. Thus, the tabs are 35 the anode 21 indirectly with the first housing part 61 connected. The insulator 50 , which is the first housing part 61 from the second housing part 62 isolated, is similar to in 9 shown trained and with the housing parts 61 . 62 connected.

13 shows a schematic, partially transparent detail view of the battery cell 2 out 2 with an attachment 80 , The attachment 80 is prismatic and has present a triangular base. The attachment 80 Adjacent to the side surface of the cell housing 3 at which the positive connection point 72 is located, and which is oriented at an angle of the present 45 ° inclined to the longitudinal direction y and to the transverse direction z. Another attachment 80 Adjacent to the side surface of the cell housing 3 at which the negative connection point 71 is located, and which is oriented at an angle of the present 45 ° inclined to the longitudinal direction y and to the transverse direction z. The add-on elements 80 are designed such that the cell housing 3 and the attachments 80 to complement each other to a cuboid.

The attachment 80 in the present case has two cooling channels extending in the stacking direction x 84 as well as a negative voltage tap 81 and a not visible in this illustration positive voltage tap 82 on. The attachment 80 can also have other elements, such as sensors.

14 shows a sectional view of the battery cell 2 out 13 along the cutting line S which is inclined to the longitudinal direction y and to the transverse direction z. The contact flags 36 the cathode 22 are from the electrode unit 10 first to the base of the cell case 3 guided. The contact flags 36 the cathode 22 are at the positive connection point 72 , which is located on the base, directly with the second housing part 62 connected. The insulator 50 , which is the first housing part 61 from the second housing part 62 isolated, is similar to in 9 shown trained and with the housing parts 61 . 62 connected.

The insulator 50 protrudes into the attachment 80 into it. Thus, the attachment is 80 firmly with the cell case 3 connected. Preferably is the insulator 50 made of a thermally highly conductive material, whereby the heat dissipation from the interior of the cell housing 3 to the cooling channels 84 in the attachment 80 is improved. For example, the insulator 50 have a metallic core with an electrically insulating coating. The negative voltage tap 81 is with the first housing part 61 connected, which is the negative terminal 11 forms. The positive voltage tap 82 is with the second housing part 62 connected, which is the positive terminal 12 forms.

The invention is not limited to the embodiments described herein and the aspects highlighted therein. Rather, within the scope given by the claims a variety of modifications are possible, which are within the scope of expert action.

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 102012223796 A1 [0004]
• US 2012/0276437 [0005]
• JP 2011-154784 [0006]

Claims (10)

Battery cell ( 2 ), comprising a cell housing ( 3 ) in which an electrode unit ( 10 ), wherein the electrode unit ( 10 ) one with a negative terminal ( 11 ) connected anode ( 21 ) and one with a positive terminal ( 12 ) connected cathode ( 22 ), Characterized in that the electrode unit ( 10 ) is designed as an electrode stack which comprises a plurality of layers of the anode ( 21 ) and several layers of the cathode ( 22 ) which are stacked in a stacking direction (x) and that the cell housing ( 3 ) is formed prismatic, wherein all surfaces of the cell housing ( 3 ) parallel or perpendicular to the stacking direction (x), and that the cell housing ( 3 ) a first housing part ( 61 ), which is the negative terminal ( 11 ) forms, and a second housing part ( 62 ), which is the positive terminal ( 12 ) forms. Battery cell ( 2 ) according to claim 1, characterized in that the first housing part ( 61 ) and the second housing part ( 62 ) metallic and by a circulating insulator ( 50 ) are electrically isolated from each other. Battery cell ( 2 ) according to claim 2, characterized in that the insulator ( 50 ) in an attachment ( 80 ) which projects a cooling channel ( 84 ) and / or a voltage tap ( 81 . 82 ) and / or has a sensor. Battery cell ( 2 ) according to one of the preceding claims, characterized in that the anode ( 21 ) Contact flags ( 35 ), and that the cathode ( 22 ) Contact flags ( 36 ), wherein the contact lugs ( 35 ) of the anode ( 21 ) and the contact flags ( 36 ) the cathode ( 22 ) on opposite sides of the electrode unit ( 10 protrude). Battery cell ( 2 ) according to claim 4, characterized in that the contact lugs ( 35 ) of the anode ( 21 ) directly with the first housing part ( 61 ), and / or that the contact lugs ( 36 ) the cathode ( 22 ) directly with the second housing part ( 62 ) are connected. Battery cell ( 2 ) according to claim 5, characterized in that the contact lugs ( 35 ) of the anode ( 21 ) cohesively with the first housing part ( 61 ), and / or that the contact lugs ( 36 ) the cathode ( 22 ) cohesively with the second housing part ( 62 ) are connected. Battery cell ( 2 ) according to claim 5, characterized in that the contact lugs ( 35 ) of the anode ( 21 ) in a form-fitting manner with the first housing part ( 61 ), and / or that the contact lugs ( 36 ) the cathode ( 22 ) in a form-fitting manner with the second housing part ( 62 ) are connected. Battery cell ( 2 ) according to one of the preceding claims, characterized in that a base area of the cell housing (90) which is at right angles to the stacking direction (x) 3 ) has a hexagonal shape. Battery cell ( 2 ) according to one of the preceding claims, characterized in that the first housing part ( 61 ) has a convex bulge, and / or that the second housing part ( 62 ) has a convex bulge. Use of a battery cell ( 2 ) according to one of the preceding claims in an electric vehicle (EV), in a hybrid vehicle (HEV), in a plug-in hybrid vehicle (PHEV), in a stationary battery, in a battery in a marine application or in a battery in an aeronautical Application.

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