Battery cell and motor vehicle comprising the battery cell

Abstract

The invention relates to a battery cell comprising: a housing having a tubular housing part, a first end plate, and a second end plate, wherein a first end of the housing part is closed by the first end plate and a second end of the housing part is closed by the second end plate; an electrode winding accommodated in an interior of the housing; and an electrolyte accommodated in the interior of the housing; wherein the electrode winding (40) has a cavity, in particular an axial cavity, in which a capillary is arranged.

Description

[0001] 23-3277

[0002] BATTERY CELL AND MOTOR VEHICLE INDICATING THE BATTERY CELL

[0003] The present invention relates to a battery cell, in particular a lithium-ion battery cell, and a motor vehicle comprising the battery cell.

[0004] Known battery cells, especially cylindrical cells, have a housing in which an electrode winding and a liquid electrolyte are arranged, through which the ion exchange between the two electrodes, between which a separator is provided, of the electrode winding is enabled in order to charge or discharge the battery cell.

[0005] With reference to Fig. 1, such a known battery cell 100 has a housing 10 with a tubular housing part 11, a first end plate 20, and a second end plate 30, wherein a first end of the housing part 11 is closed by the first end plate 20, and a second end of the housing part 11 is closed by the second end plate 30. Inside the housing 10, an electrode winding 40 with an axial cavity 41 and a liquid electrolyte 50 are provided. One of the electrodes of the electrode winding 40 is electrically connected to a first terminal 15, and the other electrode of the electrode winding is connected to the housing 10, which forms the second terminal.

[0006] The battery cell 100 rests with its second end plate 30 on a base 70, and gravity acts in the direction opposite to the direction Z shown in the coordinate system of Fig. 1.

[0007] In Fig. 1, the battery cell 100 is shown in a state where it is not yet charged, i.e., the state of charge is 0%, but the battery cell 100 has already been formed. In Fig. 2, the battery cell 100 is shown in a state after a first complete charging process, where the state of charge is 100%. As can be seen by comparing Fig. 2 with Fig. 1, in the state shown in Fig. 2, the electrolyte level 50 has increased in the Z-direction. This is due to the fact that, during charging of the battery cell 100, the electrolyte 50 is "squeezed out" of the electrodes, as illustrated by the arrows P in Fig. 2. This results in a region 23-3277 of electrolyte 50 with low conductivity near the second end plate 30 and a region with high conductivity, where the concentration of conductivity increases in the Z-direction.

[0008] Regarding the quantity of electrolyte 50 for filling the housing 10, the following conflict of objectives exists:

[0009] If the housing 10 is filled with a large amount of electrolyte 50, this leads to a plating reaction of the electrode winding 40, so that it is covered by residual electrolyte 50, which leads to a severe loss of cycle stability at the beginning of the battery cell 100's lifetime, for example within the first 50 charging cycles.

[0010] If, however, the housing 10 is filled with a small amount of electrolyte 50, the electrolyte 50 will be incorporated into the solid electrolyte interface (SEI) over the lifetime of the battery cell 100, thus consuming the electrolyte 50 and reducing the remaining amount. This can lead to "dry running," i.e., a failure of the battery cell 100, later in its service life, for example after 600 charge cycles.

[0011] One of the objectives of the present invention is to improve a battery cell.

[0012] This problem is solved by the features of the independent patent claim. Further preferred embodiments of the invention are the subject of the dependent patent claims.

[0013] According to a first aspect of the present invention, a battery cell comprises: a housing with a tubular housing part, a first end plate and a second end plate, wherein a first end of the housing part is closed by the first end plate and a second end of the housing part is closed by the second end plate; an electrode winding received in an interior of the housing; and 23-3277 an electrolyte received in the interior of the housing; wherein the electrode winding has a cavity, in some embodiments axial, in which a capillary is arranged.

[0014] In some designs, this allows the electrolyte to be transported within the capillary from an area near the second end plate, for example from the bottom of the battery cell, towards an area near the first end plate, for example from a lid of the battery cell, by means of a capillary force effected by the capillary, so that the battery cell can be prevented from “drying out”, even if the battery cell is filled with a relatively small amount of electrolyte.

[0015] The term "motor vehicle" as used here refers in particular to a passenger car, including all types of motor vehicles, hybrid and battery-powered electric vehicles, as well as vehicles such as sedans, vans, buses, trucks, delivery vans, and the like. In particular, a vehicle may have a wireless communication device or communication equipment for wireless communication with a mobile device.

[0016] Any terms used herein, such as "comprises," "includes," "features," "has," "with," or any other variant thereof, are intended to cover non-exclusive inclusion. For example, a method or apparatus that includes or features a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent in such method or apparatus.

[0017] Furthermore, unless expressly stated otherwise, “or” refers to an inclusive or and not an exclusive “or”. For example, a condition A or B is satisfied by one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). 23-3277

[0018] The terms "ein" or "eine," as used here, are defined as "one or more." The terms "ein anderer" and "ein Weitere," as well as any other variant thereof, are to be understood as "at least one more."

[0019] The term "plural", as used here, is to be understood in the sense of "two or more".

[0020] The terms "configured" or "set up" to perform a specific function (and their respective variations) are understood within the meaning of the invention to mean that the corresponding device or apparatus already exists in a configuration or setting in which it can perform the function, or at least that it is adjustable—i.e., configurable—so that it can perform the function after appropriate adjustment. Configuration can be achieved, for example, by adjusting parameters of a process sequence or by using switches or similar devices to activate or deactivate functionalities or settings. In particular, the device or apparatus can have several predetermined configurations or operating modes, so that configuration can be carried out by selecting one of these configurations or operating modes.

[0021] Preferred embodiments of the invention and their further developments are described below, which, unless expressly excluded, can be combined with each other as desired and with the second aspect of the invention described below.

[0022] In some designs, the second end plate rests on a surface when the battery cell is used as intended, with the cavity and capillary extending perpendicular to the surface. In some designs, the cavity and capillary extend parallel or antiparallel to the direction in which gravity acts.

[0023] In some designs, the length of the capillary is equal to or greater than the length of the electrode winding, which in some designs is axial.

[0024] In some designs, the electrode winding is spaced away from the first end plate and / or the second end plate. 23-3277

[0025] In some designs, pores are provided on the inside of the capillary, with the pores having a diameter in the range of 0.1 pm to 0.5 mm.

[0026] In some versions, the electrolyte contains a carbonate-containing solvent, in some versions ethylene carbonate, dimethyl carbonate, diethyl carbonate or mixtures thereof, and / or LiPFe as a conducting salt.

[0027] In some designs, the axial ends of the capillary are flush with the axial ends of the electrode winding.

[0028] In some designs, the capillary extends towards the second end plate with respect to the electrode winding. This is particularly advantageous when the second end plate forms the base of the battery cell, as it allows electrolyte located near the second end plate and at a distance from the electrode winding to be transported through the capillary towards the first end plate.

[0029] In some designs, the capillary is designed to transport at least part of an electrolyte located near the second end plate (and spaced away from the electrode winding) against gravity towards the first end plate by means of the capillary effect.

[0030] In some versions, the capillary has an inner diameter ranging from 0.1 mm to 1.5 mm.

[0031] A second aspect of the present invention relates to a motor vehicle having a battery cell as described above.

[0032] The features and advantages described in relation to the first aspect of the invention and its advantageous embodiment also apply, at least where technically feasible, to the second aspect of the invention and its advantageous embodiments, and vice versa. 23-3277

[0033] Further advantageous developments result from the following description of preferred embodiments. This is shown, in part schematically:

[0034] Fig. 1 shows a state-of-the-art battery cell filled with electrolyte before a first charging process.

[0035] Fig. 2 shows the battery cell filled with electrolyte as shown in Fig. 1 after the first charging process.

[0036] Fig. 3 shows a battery cell according to the invention in one embodiment,

[0037] Fig. 4 shows the battery cell shown in Fig. 3, which is filled with an electrolyte, and

[0038] Fig. 5 shows a motor vehicle with a battery cell according to one embodiment.

[0039] Fig. 3 schematically shows a battery cell 100 according to the invention in an embodiment without electrolyte. The battery cell 100 has a housing 10 with a tubular housing part 11, a first end plate 20 and a second end plate 30. Here, a first end of the housing part 11 is closed by the first end plate 20, and a second end of the housing part 11 is closed by the second end plate 30.

[0040] Inside the housing 10 is an electrode winding 40 which has a cavity 41, axial in some versions, in which a capillary 60 is arranged.

[0041] Pores (not shown) are provided on an inner surface 61 of the capillary 60, with a diameter ranging from 0.1 µm to 0.5 mm. In some embodiments, the capillary 60 can have an inner diameter ranging from 0.1 mm to 1.5 mm.

[0042] Fig. 2 shows a state in which the battery cell 100 is infested with electrolyte 50.

[0043] The electrolyte 50 can be a carbonate-containing solvent, in some 23-3277

[0044] Versions containing ethylene carbonate, dimethyl carbonate, diethyl carbonate or mixtures thereof, and / or LiPFe as a conducting salt.

[0045] When the battery cell 100 is used as intended, the second end plate 30, which forms a base of the battery cell 100, rests on a preferably flat surface 70, with the cavity 41 and the capillary 60 extending perpendicular to the surface 70, i.e., vertically in the Z-direction. In this case, gravity acts particularly in the direction opposite to the Z-direction.

[0046] The electrode winding 40 is spaced apart from the first end plate 20 and the second end plate 30. Due to this distance between the electrode winding 40 and the second end plate 30, electrolyte 50 can collect between the electrode winding 40 and the second end plate 30.

[0047] The capillary forces exerted by the capillary 60 allow electrolyte 50, which is located near the second end plate 30, to be transported towards the first end plate 20 against the effect of gravity.

[0048] In particular, the capillary 60 is designed to transport at least part of an electrolyte 50 located near the second end plate 30 against gravity towards the first end plate 20 by means of the capillary effect.

[0049] Preferably, the (axial) length L2 of the capillary 60 is equal to or greater than the length L1 of the electrode winding 40, which in some embodiments is axial.

[0050] In the embodiment shown in Figs. 3 and 4, the axial ends 62, 63 of the capillary 60 are flush with the axial ends 42, 43 of the electrode winding 40.

[0051] In embodiments not shown, the capillary 60 can also project towards the second end plate 30 with respect to the electrode winding 40. This allows electrolyte 50 located near the second end plate 30 to be transported through the capillary 60 towards the first end plate 20.

[0052] Fig. 5 shows a motor vehicle 200, which has a battery cell 100 as described above. The battery cell 100 can, for example, be configured to supply electrical energy to a drive motor of the motor vehicle 200 (not shown).

Claims

23-3277 REQUIREMENTS 1. Battery cell (100) comprising: a housing (10) with a tubular housing part (11), a first end plate (20) and a second end plate (30), wherein a first end of the housing part (11) is closed by the first end plate (20), and a second end of the housing part (11) is closed by the second end plate (30); an electrode winding (40) received in an interior of the housing (10); and an electrolyte (50) received in the interior of the housing (10); wherein the electrode winding (40) has a cavity (41), in particular an axial one, in which a capillary (60) is arranged.

2. Battery cell (100) according to claim 1, wherein the second end plate (30) rests on a substrate (70) when the battery cell (100) is used as intended, and the cavity (41) and the capillary (60) extend perpendicular to the substrate (70).

3. Battery cell (100) according to one of the preceding claims, wherein a length (L2) of the capillary (60) is equal to or greater than a, in particular axial, length (L1) of the electrode winding (40).

4. Battery cell (100) according to one of the preceding claims, wherein the electrode winding (40) is spaced apart from the first end plate (20) and / or the second end plate (30).

5. Battery cell (100) according to one of the preceding claims, wherein pores are provided on an inner side (61) of the capillary (60), and the pores have a diameter in the range between 0.1 pm and 0.5 mm. 23-3277 6. Battery cell (100) according to any one of the preceding claims, wherein the electrolyte contains a carbonate-containing solvent, in particular ethylene carbonate, dimethyl carbonate, diethyl carbonate or mixtures thereof, and / or LiPFe as a conducting salt.

7. Battery cell (100) according to any one of the preceding claims, wherein axial ends (62, 63) of the capillary (60) are flush with axial ends (42, 43) of the electrode winding (40).

8. Battery cell (100) according to one of claims 1 to 6, wherein the capillary (60) projects towards the second end plate (30) with reference to the electrode winding (40).

9. Battery cell (100) according to any one of the preceding claims, wherein the capillary (60) is configured to transport at least a portion of an electrolyte (50) located near the second end plate (30) against gravity towards the first end plate (20) by means of capillary action.

10. Battery cell (100) according to any one of the preceding claims, wherein the The capillary (60) has an inner diameter in the range of 0.1 mm to 1.5 mm.

11. Motor vehicle (200) comprising a battery cell (100) according to one of the preceding claims.

Images