Search

CN-121986404-A - Battery cell and vehicle with same

CN121986404ACN 121986404 ACN121986404 ACN 121986404ACN-121986404-A

Abstract

The invention relates to a battery cell comprising a housing (10) which comprises a tubular, in particular hollow-cylindrical, housing part, a first end plate (20), in particular having a circular outer circumference and having a first central section, and a second end plate (30), in particular having a circular outer circumference and having a second central section, the first end of the housing part being closed by the first end plate and the second end of the housing part being closed by the second end plate, an electrode winding body which is accommodated inside the housing and has a strip-shaped first electrode (having a first current collector) and a strip-shaped second electrode (having a second current collector), which are arranged in layers and are wound around the longitudinal axis of the battery cell with a first and a second separator in between, and at least one connecting element which is provided for limiting the movement of the first central section in the direction of the longitudinal axis away from the interior of the housing and limiting the movement of the second central section in the direction of the longitudinal axis away from the interior of the housing, in particular for preventing or at least limiting the corresponding bulging of the first end plate and the second end plate from being present in relation to the interior of the housing, in particular on the basis of an overpressure of the interior of the housing.

Inventors

  • F. Morgan stern
  • J mckinney

Assignees

  • 宝马股份公司

Dates

Publication Date
20260505
Application Date
20240912
Priority Date
20231009

Claims (14)

  1. 1. A battery cell (100, 100A, 100B, 100C) comprising: -a housing (10) comprising a tubular, in particular hollow-cylindrical, housing part (11), a first end plate (20) and a second end plate (30), in particular the first end plate having a circular periphery and having a first central section (21), in particular the second end plate having a circular periphery and having a second central section (31), 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 body (40) housed inside the casing (10) having a strip-shaped first electrode with a first current collector (50) and a strip-shaped second electrode with a second current collector (60), the first and second electrodes being wound around a longitudinal axis (L) of the battery cell (100) in a layered arrangement with first and second separators (70, 71) sandwiched therebetween, and -At least one connecting element (80, 81, 82, 83, 84) provided for limiting the movement of the first central section (21) away from the interior of the housing (10) in the direction of the longitudinal axis (L) and limiting the movement of the second central section (31) away from the interior of the housing (10) in the direction of the longitudinal axis (L), in particular in order to prevent or at least limit the respective bulging of the first and second end plates (20, 30), in particular due to an overpressure present inside the housing (10) with respect to the exterior of the housing (10).
  2. 2. The battery cell (100, 100A, 100B, 100C) according to claim 1, wherein the first current collector (50) is electrically conductively connected to the first terminal (101) of the battery cell (100) by a first contact element (51), in particular at least in sections, which is disc-shaped, wherein the first contact element (51), in particular a projection of the first contact element (51), which extends in the direction of the first end plate (20) along the longitudinal axis (L), is electrically conductively connected to the first terminal (101) by a welded connection (81), in particular between the projection of the first contact element (51) and the first central section (21), and the second current collector (60) is electrically conductively connected to the second terminal (102) of the battery cell (100) by a second contact element (61), in particular at least in sections, which is disc-shaped.
  3. 3. The battery cell (100) according to claim 1 or 2, wherein the at least one connecting element (80) has a hollow or solid, in particular non-conductive, rod (80) which extends along the longitudinal axis (L), wherein a first axial end of the rod (80) is connected to the first central section (21), in particular by connection of the first axial end of the rod (80) to the first contact element (51), and a second axial end of the rod (80) is connected to the second central section (31).
  4. 4. A battery cell (100) according to claim 3, wherein the rod (80) extends through a cavity (41) of the electrode winding body (40) extending along the longitudinal axis (L).
  5. 5. The battery cell (100) of claim 4, wherein the electrode jelly roll (40) is wound on a rod (80).
  6. 6. The battery cell (100A) according to claim 2, wherein the at least one connecting element (80, 81, 82, 83, 84) has a first pin (82) or a first screw which is connected to the first contact element (51) and/or the first central section (21) and which extends into the cavity (41) of the electrode winding body (40) extending along the longitudinal axis (L) and is connected in a force-locking manner to the inner wall of the cavity (41) or to the inner wall of the tube (42) extending in the cavity (41), and/or has a second pin (83) or a second screw which is connected to the second contact element (61) and/or the second central section (31) and which extends into the cavity (41) of the electrode winding body (40) extending along the longitudinal axis (L) and is connected in a force-locking manner to the inner wall of the cavity (41) or to the inner wall of the tube (41) extending in the cavity (42).
  7. 7. The battery cell (100, 100A, 100B, 100C) according to any of the preceding claims, wherein the first end plate (20) comprises a first perforated disc (22) with a first opening and comprises a first central plate (23), which is electrically insulated from the first perforated disc (22) by a first insulator (120), the first opening being closed by a section of the first central plate (23) and a section of the first insulator (120), and the first central plate (23) has a first central section (21).
  8. 8. The battery cell (100, 100A, 100C) according to any of the preceding claims, wherein the second end plate (30) comprises a second orifice plate (32) with a second opening and comprises a second central plate (33), the second central plate being electrically insulated from the second orifice plate (32) by a second insulator (130), the second opening being closed by a section of the second central plate (33) and a section of the second insulator (130), and the second central plate (33) having a second central section (31).
  9. 9. The battery cell (100, 100A) according to any of the preceding claims, wherein the second contact element (61) has a first connection portion (62) which is electrically conductively connected to an inner wall of the housing part (11), in particular by a clamping connection and/or a welded connection, and the housing part (11) is electrically conductively connected to the second terminal (102).
  10. 10. The battery cell (100B, 100C) according to claim 2 or claim 7 and claim 2, wherein the at least one connecting element (80, 81, 82, 83, 84, 85) has a welded connection (84, 85) between the second contact element (61), in particular a projection of the second contact element (61) extending in the direction of the longitudinal axis (L) towards the second end plate (30), and the second central section (31), and a welded connection (81) by means of which the projection of the first contact element (51) extending in the direction of the longitudinal axis (L) towards the first end plate (20) is connected to the first terminal (101), the cross-sectional area of the welded connection perpendicular to the longitudinal axis (L) being larger than the inner diameter of the electrode winding body (40).
  11. 11. The battery cell (100B, 100C) of claim 10, wherein the second end plate (30) comprises a second perforated disc (32) having a second opening and comprises a second central plate (33) electrically insulated from the second perforated disc (32) by a second insulator (130), the second opening being closed by a section of the second central plate (33) and the second insulator (130), and the second central section (31) being formed by a section of the second perforated disc (32) surrounding the second central plate (33).
  12. 12. The battery cell (100B, 100C) according to claim 10 or 11, wherein the second end plate (30) is connected with the housing part (11), in particular with an inwardly protruding protrusion (12) of the housing part (11), by means of a laser welding process.
  13. 13. The battery cell (100, 100A, 100B, 100C) according to any of the preceding claims, wherein the second end plate (30), in particular the second end plate (32), has a predetermined breaking point (34).
  14. 14. Vehicle (200), in particular an electric vehicle or a hybrid vehicle, having a battery cell (100, 100A, 100B, 100C) according to any of the preceding claims and an electric drive motor (201) for driving the vehicle (200), the battery cell (100, 100A, 100B, 100C) being provided for supplying electric energy to the electric drive motor (201) for driving the vehicle (200).

Description

Battery cell and vehicle with same Technical Field The present invention relates to a battery cell, in particular a cylindrical battery cell, and a vehicle having the battery cell. Background For example, battery cells that may be used to power a vehicle motor to drive the vehicle are typically hermetically sealed to protect the battery cells from the environment, particularly water and oxygen. In this case, a higher internal pressure than the cell environment is generally present inside the cell housing. During operation of the battery cell, this internal pressure increases based on (parasitic) side reactions between the electrolyte and the cathode and anode active materials, especially when the battery cell is in a high state of charge. This can lead to bulging of the battery cells, thereby affecting the integrity of the battery pack (which contains a plurality of battery cells interconnected in one container) and the attachment of the individual battery cells to the bottom of the container by means of an adhesive. This bulging must be compensated for in the battery pack by allocating a certain space so that the battery cells can bulge or compress the battery cells from the outside in order to maintain the size of the battery cells within a predetermined maximum size range. In prismatic cells, for example, spacers are provided between the cells and the pressure plate (tie rod) that keep the dimensions of the cells within a predetermined maximum dimension. In cylindrical cells, such bulging is largely limited to the bulging of the end plates in the longitudinal direction, i.e. in the axial direction of the housing, which is essentially planar, since the outer dimensions of the cylindrical housing parts, the axial ends of which are closed by the end plates, can be substantially maintained even at elevated internal pressures. The larger the diameter of the cylindrical cell, the more difficult it is to limit the end plate bulging, since the force F acting on the plate according to the formula "force = pressure x area" increases linearly with area. In addition, most cylindrical cells are contacted on one of the end plates (outer side), which results in additional mechanical stress on the bus bars that bear against the cell terminals or poles and causes integration problems for cells with higher internal pressure. Since the cylindrical battery cells are provided with venting means on at least one of the end plates, this presents additional challenges for the integration operation if the venting means is conventionally designed as a predetermined breaking point in order to allow gas and/or fragments to escape from the battery cells for safety reasons, for example when an internal pressure rise occurs due to a thermal event within the battery cells. Since these battery cells have to be integrated into the battery pack, the bulge in the longitudinal direction may lead to mechanical failure or affect the safety and integrity of the battery pack. This can be a particular challenge for cells with new electrolytes (e.g., liquid gas electrolytes) or cells with higher silicon germanium content or other less stable active materials, which typically have higher gas pressures than cells with standard electrolytes or standard active materials. Disclosure of Invention The object of the present invention is to provide an improved battery cell. This object is achieved by the features of claim 1. Further preferred embodiments of the invention are the subject of the dependent claims. According to a first aspect of the present invention, a battery cell according to one embodiment includes: A housing comprising a tubular (in some embodiments hollow cylindrical, in some embodiments electrically conductive) housing part, a first end plate (in some embodiments having a circular periphery and having a first central section in some embodiments located at a central region of the first end plate), and a second end plate (in some embodiments having a circular periphery and having a second central section in some embodiments located at a central region of the second end plate), the first end of the housing part being closed by the first end plate and the second end of the housing part being closed (hermetically) by the second end plate; An electrode winding body accommodated inside the case, the electrode winding body comprising a strip-shaped first electrode (having a first active material, such as a cathode active material, in some embodiments, and having a first current collector, such as a cathode current collector) and a strip-shaped second electrode (having a second active material, such as an anode active material, in some embodiments, and having a second current collector, such as an anode current collector), the first and second electrodes being arranged in layers and wound around the longitudinal axis of the battery cell with the first and second separators interposed therebetween, and At least one connecting element provided for