Battery unit for a vehicle

Abstract

Aspects of the present invention relate to a battery cell (202) for a vehicle, the battery cell (202) comprising: a battery cell housing (104), at least one electrode stack (110) disposed in the battery cell housing (104), and at least one compressible element (204) disposed in the battery cell housing (104), the at least one compressible element (204) configured to counteract any bulging of the battery cell (102).

Description

Technical Field

[0001] This disclosure relates to battery cells for vehicles. Aspects of the invention relate to battery cells for vehicles, batteries for vehicles, vehicles, methods of manufacturing battery cells for vehicles, methods of manufacturing batteries for vehicles, and apparatus for manufacturing battery cells for vehicles. Background Technology

[0002] Some known lithium-ion pouch cells and prismatic cells are prone to bulging due to various reversible and irreversible electrochemical reactions that occur during their charge and discharge cycles. Some known cells are known to expand and contract slowly and steadily (also known as "cell breathing"). Bulging can occur throughout the lifespan of pouch and prismatic cells due to a number of factors, including ion insertion into the electrodes, gas generation from side reactions within the cell, and the growth of a solid electrolyte interphase (SEI) layer due to degradation. Irreversible bulging factors can lead to cell capacity loss, high stress concentration on the electrodes, and / or excessive cell-to-cell load transfer within the cell stack, which poses a significant challenge to cell-to-module / pack integration. These problems can result in cell stack bending, busbar weld misalignment, and / or detachment of the cell carrier within the cell stack.

[0003] It is known to control the bulging effect and prevent or limit the aforementioned challenges by introducing compression elements (in the form of pads) between the battery cells in a battery. Such compression elements are used to apply a constant force at the interface between adjacent battery cells. This restoring force is typically achieved by compressing the cell stack assembly after the endplates have been assembled. This provides both mechanical and electromechanical benefits to the cell. During the stack assembly process, compression pads are inserted between each adjacent cell, or periodically. A major challenge arises in controlling cell-pad-cell alignment. Once the stack assembly is compressed at its endplates, unintended misalignment between the cells and pads is amplified, potentially leading to uneven pressure distribution along the cell interface and relative displacement between cells. Such problems can cascade and trigger other issues within the surrounding battery pack.

[0004] The purpose of this invention is to address one or more of the disadvantages associated with the prior art. Summary of the Invention

[0005] The various aspects and embodiments of the present invention provide, as claimed in the appended claims, a battery cell for a vehicle, a battery for a vehicle, a vehicle, a method for manufacturing a battery cell for a vehicle, a method for manufacturing a battery for a vehicle, and an apparatus for manufacturing a battery cell for a vehicle.

[0006] According to one aspect of the invention, a battery cell for a vehicle is provided, comprising a battery cell housing and at least one compressible element disposed in the battery cell housing, the at least one compressible element being configured to counteract any bulging of the battery cell.

[0007] According to one aspect of the present invention, a battery cell for a vehicle is provided, comprising: a battery cell housing, at least one electrode stack disposed in the battery cell housing, and at least one compressible element disposed in the battery cell housing, the at least one compressible element being configured to counteract any bulging of the battery cell.

[0008] The battery cells are independently self-constrained, making the compressible element an internal feature within the battery cell housing (as opposed to the prior art where the compressible element is located outside the battery cell housing but between adjacent battery cells). This not only helps control electrode bulging, but also ensures that the compressible element can be tightly controlled in its alignment with the electrode stack. This will also reduce the number of parts required during the stacking assembly process (only the battery cells need to be aligned with each other).

[0009] In some embodiments, the battery cell includes at least one can, wherein each of at least one electrode stack is disposed in one of the at least one can, and at least a portion of the at least one can is conductive. The at least one can may serve as both part of the battery cell housing and a conductive terminal of the battery cell.

[0010] In some embodiments, at least one compressible element may not be disposed in at least one tank. While there are certain benefits associated with disposing of the compressible element in a tank, embodiments in which the compressible element is not disposed in at least one tank can still benefit from the advantages discussed above.

[0011] In some embodiments, the battery cell includes two cans, and at least one compressible element is disposed between the two cans. This is a particularly convenient and efficient location for the compressible element. In some embodiments, at least one can includes a recess for receiving at least a portion of the at least one compressible element. The recess can improve the alignment of the compressible element within the battery cell.

[0012] In some embodiments, at least one compressible element is planar. The planar shape can be conveniently positioned within the battery cell while counteracting any bulging therein.

[0013] In some embodiments, each of at least one electrode stack includes a plurality of electrodes, each extending along a first longitudinal axis, and at least one compressible element extends in a first plane parallel to the first longitudinal axis of each of the plurality of electrodes. This orientation is intended to mitigate any bulging effect along the direction in which such a phenomenon is most likely to occur.

[0014] In some implementations, at least one compressible element is preloaded. Preloading the compressible element allows for a more uniform force response to be provided by the compressible element.

[0015] In some implementations, the compressible element may include foam (e.g., polyurethane foam or silicone foam). Such materials are particularly advantageous for providing the desired resilience.

[0016] Alternatively or additionally, the compressible element may include a dielectric material. In such an embodiment, the compressible element may be additionally used for two components (e.g., two adjacent cans) within an electrically isolated battery cell.

[0017] According to another aspect of the invention, a battery for a vehicle is provided, the battery comprising a plurality of battery cells assembled together, wherein the plurality of battery cells are as described above.

[0018] In some embodiments, there are no compressible elements between adjacent battery cells (i.e., outside each battery cell). Because embodiments of the invention can provide the aforementioned benefits due to the compressible elements being inside the battery cell housing, including them between adjacent battery cells (although they may be present in some embodiments) may not be necessary.

[0019] According to another aspect of the invention, a vehicle is provided that includes a battery cell or a battery as described above.

[0020] According to another aspect of the invention, a method for manufacturing a battery cell is provided, the method comprising: assembling at least one electrode stack in a battery cell housing, and assembling at least one compressible element in the battery cell housing, the at least one compressible element being configured to counteract any bulging of the battery cell.

[0021] In some implementations, the method may include preloading at least one compressible element.

[0022] According to another aspect of the present invention, a method for manufacturing a battery for a vehicle is provided, comprising manufacturing a plurality of battery cells as described above, and assembling the plurality of battery cells together.

[0023] According to another aspect of the invention, an apparatus for manufacturing a battery cell is provided, the apparatus comprising a loading device for preloading a compressible element and an assembly device for assembling the compressible element into a battery cell housing.

[0024] Within the scope of this application, it is expressly intended that various aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, in the claims, and / or in the following description and drawings, and in particular their various features, may be adopted independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination, unless such features are incompatible. The applicant reserves the right to amend any originally filed claim or accordingly file any new claim, including the right to modify any originally filed claim to be subordinate to any other claim and / or incorporated into any other claim, although not initially claimed in this manner. Attached Figure Description

[0025] One or more embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0026] Figure 1 A three-dimensional view of the battery cell is shown;

[0027] Figure 2 It shows Figure 1 A top view of the battery cell;

[0028] Figure 3 The section cut along line AA is shown. Figure 2 A cross-sectional view of the battery cell;

[0029] Figure 4 It shows Figure 3 A detailed cross-sectional view of the battery cell, section B;

[0030] Figure 5 A schematic cross-sectional view of a battery cell according to an embodiment of the present invention is shown;

[0031] Figure 6 A perspective view of a battery according to an embodiment of the present invention is shown;

[0032] Figure 7 It shows Figure 6 Side view of the battery;

[0033] Figure 8 The CC section along the line is shown. Figure 7 A cross-sectional view of the battery;

[0034] Figure 9 It shows Figure 8A detailed cross-sectional view of the battery (D).

[0035] Figure 10 A method for manufacturing a battery cell according to an embodiment of the present invention is shown;

[0036] Figure 11 A method for manufacturing a battery according to an embodiment of the present invention is shown;

[0037] Figure 12 An apparatus for manufacturing a battery cell according to an embodiment of the present invention is schematically illustrated; and

[0038] Figure 13 A vehicle according to an embodiment of the present invention is shown. Detailed Implementation

[0039] Figure 1 A perspective view of battery cell 102 is shown. As described below, battery cell 102 can be assembled with other identical or similar battery cells 102 to form a battery. The battery can be a vehicle battery (e.g., a traction battery). In some embodiments, the battery can be a pouch cell or a prismatic cell. In some embodiments, the battery can be any battery with a stacked electrode arrangement (as further described below).

[0040] Battery cell 102 includes two cans 120, namely a first can 122 and a second can 124 stacked on top of each other, a first cap 106, and a second cap 108 (in Figure 3 and Figure 4 (shown in the figure) and a battery cell frame 130 extending around the periphery of the battery cell 102. The battery cell housing 104 of the battery cell 102 includes a first cover 106, a second cover 108, the battery cell frame 130, and portions of two canisters 120. Figure 2 It shows Figure 1 A top view of the battery cell 102.

[0041] Figure 3 The section cut along section line AA is shown. Figure 2 A cross-sectional view of battery cell 102. (See diagram below.) Figure 3As shown, the battery cell 102 includes a pair of electrode stacks 110 (i.e., a stacked arrangement of electrodes). The pair of electrode stacks 110 includes a first electrode stack 112 and a second electrode stack 114. Each electrode stack in the electrode stacks 110 is disposed within a can 120. The two cans 120 include a first can 122 and a second can 124, wherein the first can 122 is stacked on top of the second can 124. The first electrode stack 112 is disposed within the first can 122, and the second electrode stack 114 is disposed within the second can 124. The can 120 contains an electrolyte such that the electrode stacks 110 are in contact with the electrolyte. In some embodiments, the electrolyte may be a liquid. In other embodiments, the electrolyte may be a solid.

[0042] A first cap 106 is engaged with a first can 122 to seal the volume containing the first electrode stack 112. Similarly, a second cap 108 is engaged with a second can 124 to seal the volume containing the second electrode stack 114. In such sealed volumes, each electrode stack 110 resides in an electrolyte. Each electrode stack 110 is electrically connected to each of the first can 122 and the second can 124, such that can 120 serves as an electrical terminal of the battery cell 102.

[0043] Figure 4 It shows Figure 3 Details B of the battery cell 102. Each electrode stack 110 includes a stack of individual electrodes extending parallel to a first longitudinal axis 118 and converging and terminating in tabs 116. At least one tab 116 is a converging portion of the anode of the corresponding electrode stack 110, and at least one other tab 116 is a converging portion of the cathode of the corresponding electrode stack 110. The tabs 116 are electrically connected to cans 120. More specifically, at least one tab 116 of each electrode stack 110 is electrically connected to a first can 122, and at least one other tab 116 of the corresponding electrode stack 110 is electrically connected to a second can 124.

[0044] like Figure 4 As shown, the second can 124 includes a second can hole 126, allowing the second electrode stack 114 disposed in the second can 124 to be electrically connected to the first can 122. Figure 4In the non-limiting embodiment shown, a portion of the first can 122 extends through the second can opening 126, allowing for electrical connection. In an alternative embodiment, tabs 116 of the second electrode stack 114 connected to the first can 122 may extend through the second can opening 126, so that no part of the first can 122 needs to extend through the second can opening 126. At the same end of the battery cell 102 on opposite sides of the first can 122, tabs 116 of the first electrode stack 112 disposed within the first can 122 are connected to the first can 122. Thus, the first can 122 is electrically connected on opposite surfaces to tabs 116 of two different electrode stacks 110. The tabs 116 connected to the first can 122 have the same polarity, such that the first can 122 serves as either the positive or negative terminal of the battery cell 102.

[0045] At the opposite end of battery cell 102 (in Figure 4 At a location (not shown in the diagram), the first can 122 has a first can hole, allowing another tab 116 of the first electrode stack 112 disposed in the first can 122 to form an electrical connection with the second can 124. The opposite tab 116 of the electrode stack 110 disposed in the second can 124 (in the diagram) is located at a location where the first can 122 has a first can hole, allowing the other tab 116 of the first electrode stack 112 disposed in the second can 124 to form an electrical connection with the second can 124. Figure 4 (Not shown) is also electrically connected to the second can 124. Therefore, the second can 124 is electrically connected on opposite surfaces to the tabs 116 of the two electrode stacks 110. The tabs 116 connected to the second can 124 have the same polarity, such that the second can 124 becomes either the positive or negative terminal of the battery cell 102 (opposite to the polarity of the first can 122).

[0046] Electrical insulators, such as coatings or inserts (not visible in the figures), are provided between the first can 122 and the second can 124 to electrically isolate one from the other.

[0047] Figure 5 A schematic cross-sectional view of a battery cell 202 according to an embodiment of the present invention is shown. The battery cell 202 may include any or all of the features described above with respect to battery cell 102. For example... Figure 5As shown, the battery cell 202 includes a battery cell housing 104 and a pair of cans 120 (i.e., a first can 122 and a second can 124), wherein each can 120 contains an electrode stack 110. Specifically, the first can 122 contains a first electrode stack 112, and the second can 124 contains a second electrode stack 114. The battery cell 202 also includes a compressible element 204. In a non-limiting embodiment, the compressible element 204 is disposed between adjacent cans 120, and not within any one can 120. In such an embodiment, the compressible element 204 is not exposed to or in contact with the electrolyte contained in the can 120. In this illustrated non-limiting embodiment, each can 120 includes a recess 128 for receiving at least a portion of at least one compressible element 204.

[0048] The compressible element 204 is configured to counteract any bulging of the battery cell 202. Specifically, bulging of a portion of the battery cell 202 can exert a force on the compressible element 204. In response, the compressible element 204 can apply a counterforce on the bulging portion. Therefore, the resultant force applied outside the battery cell housing 104 due to bulging can be zero or at least reduced due to the presence of the compressible element 204. In the absence of such a restorative counterforce, such bulging can accumulate in a battery comprising multiple stacked battery cells, increasing the likelihood of battery failure or suboptimal operation.

[0049] The compressible element 204 can be preloaded before being assembled within the battery cell housing 104. The compressible element 204 may have a generally nonlinear stress-strain curve associated with it (which defines the operating limits of the compressible element 204), but this curve includes generally linear segments. Preloading the compressible element 204 can mean that the compressible element 204 is compressed during operation and provides a restoring force that can be substantially constant. Operation at the upper limit of the stress-strain curve may cause the battery cell 202 to fail over time.

[0050] exist Figure 5 In the non-limiting embodiment shown, the compressible element 204 is planar. That is, the compressible element 204 generally extends within the first plane 206. Figure 5In the non-limiting embodiment shown, the first plane 206 is parallel to the first longitudinal axis 118 of the electrode stack 110. Although the compressible element 204 has a (non-zero) thickness in a direction perpendicular to the first plane 206, this dimension is much smaller than the two orthogonal dimensions of the compressible element 204 (i.e., the length and width defining the first plane 206). The length of the compressible element 204 (i.e., the dimension along the first plane 206 parallel to the first longitudinal axis 118) can be smaller than the length of the electrode stack 110. This arrangement allows the compressible element 204 to be positioned between adjacent cans 120 without interfering with the connection of the tabs 116 of each of the electrode stacks 110 to each can in the cans 120.

[0051] In alternative embodiments, the compressible element 204 may have other forms.

[0052] In some embodiments, more than one compressible element 204 may be disposed within the battery cell housing 104.

[0053] In some embodiments, one or more compressible elements 204 may be disposed in the battery cell housing 104 in addition to, for example, Figure 5 The locations shown are outside the adjacent tanks 120. In such embodiments, one or more compressible elements 204 may still not be disposed within the tank 120 and are therefore isolated from the electrolyte contained within the tank 120. In other embodiments, one or more compressible elements 204 may be disposed within one or both of the tanks 120 and are therefore in contact with the electrolyte. In some non-limiting embodiments, one or more compressible elements 204 may be disposed between one or more electrode stacks of the electrode stack 110 and the battery cell housing 104. In some embodiments, for example, one or more electrode stacks of the electrode stack 110 may be disposed between a pair of compressible elements 204.

[0054] While those skilled in the art will understand that compressible element 204 may include any suitable compressible material, in some non-limiting embodiments, compressible element 204 may include polyurethane or silicone. In some embodiments, compressible element 204 may include foam (e.g., polyurethane foam or silicone foam).

[0055] Figure 6 A perspective view of a battery 602 according to an embodiment of the present invention is shown. The battery 602 includes a plurality of battery cells 202 stacked on top of each other. Figure 6In the non-limiting embodiment shown, battery 602 includes a battery casing 604 surrounding at least a portion of battery cell 202. In such a battery 602, battery cells 202 are electrically connected to each other, specifically, a can 120 serving as the positive terminal of one battery cell 202 is electrically connected to a can 120 serving as the negative terminal of an adjacent battery cell 202 (e.g., a first can 122 of one battery cell 202 is electrically connected to a second can 124 of the next battery cell 202, such as...). Figure 9 (As shown). In this stack configuration, one end of the can 120 (e.g., the first can 122) serves as the positive terminal of the battery 602, and the other end of the can 120 (e.g., the second can 124) at the opposite end of the stack serves as the negative terminal of the battery 602.

[0056] When assembling battery cells to form a battery, placing the compressible element 204 within the battery cell 202 eliminates any requirements for assembling and aligning the compressible element between battery cells. Therefore, the assembly of the battery 602 according to an embodiment of the invention is advantageously simplified compared to prior art arrangements. In some embodiments, the additional compressible element may be disposed outside adjacent battery cells and between adjacent battery cells. In other embodiments, there is no compressible element between adjacent battery cells.

[0057] Figure 7 It shows Figure 6 Side view of battery 602.

[0058] Figure 8 The section cut along the CC line is shown. Figure 7 Cross-sectional view of battery 602.

[0059] Figure 9 It shows Figure 8 Details of battery 602 D.

[0060] Figure 10 A method 1000 for manufacturing a battery cell 202 according to an embodiment of the present invention is shown. In block 1002, method 1000 includes assembling at least one electrode stack 110 in a battery cell housing 104. In block 1004, method 1000 includes preloading at least one compressible element 204, the at least one compressible element being configured to counteract any bulging of the battery cell 102. In block 1006, method 1000 includes assembling at least one compressible element 204 in the battery cell housing 104. In some embodiments, (e.g., depending on the material of the compressible element 204) the preloading step (block 1004) may not occur.

[0061] Figure 11A method 1102 for manufacturing a battery 602 according to an embodiment of the present invention is shown. Method 1102 includes manufacturing a plurality of battery cells 202 according to method 1000 described above, and subsequently assembling the plurality of battery cells 202 together to form a battery 602.

[0062] Figure 12 An apparatus 1202 for manufacturing a battery cell 202 according to an embodiment of the present invention is schematically shown. The apparatus 1202 includes a loading device 1204 for preloading a compressible element 204 and an assembly device 1208 for assembling the compressible element 204 into a battery cell housing 104 to form a battery cell 202.

[0063] Figure 13 A vehicle 1302 including a battery 602 is shown according to an embodiment of the present invention.

[0064] It will be understood that various changes and modifications can be made to this invention without departing from the scope of this application.

Claims

1. A battery cell for a vehicle, comprising: Battery cell housing; At least one electrode stack is disposed in the battery cell housing; as well as At least one compressible element is disposed in the battery cell housing, the at least one compressible element being configured to counteract any bulging of the battery cell.

2. The battery cell according to claim 1, comprising at least one canister, wherein, Each of the at least one electrode stack is disposed in one of the at least one cans, and at least a portion of the at least one can is conductive.

3. The battery cell according to claim 2, wherein, The at least one compressible element is not located in the at least one tank.

4. The battery cell according to claim 3, comprising two canisters, wherein, The at least one compressible element is disposed between the two tanks.

5. The battery cell according to any one of claims 2 to 4, wherein, The at least one can includes a recess for accommodating at least a portion of the at least one compressible element.

6. The battery cell according to any one of claims 1 to 5, wherein, The at least one compressible element is planar.

7. The battery cell according to claim 6, wherein, Each of the at least one electrode stack includes a plurality of electrodes extending along a first longitudinal axis, and wherein the at least one compressible element extends in a first plane parallel to the first longitudinal axis of each of the plurality of electrodes.

8. The battery cell according to any one of claims 1 to 7, wherein, The at least one compressible element is preloaded.

9. A battery for a vehicle, comprising a plurality of battery cells assembled together, wherein, The plurality of battery cells are claimed in any one of claims 1 to 8.

10. The battery according to claim 9, wherein, There are no compressible elements between adjacent battery cells.

11. A vehicle comprising a battery cell according to any one of claims 1 to 8 or comprising a battery according to claim 9 or 10.

12. A method for manufacturing a battery cell, comprising: At least one electrode is stacked and assembled in the battery cell housing; as well as At least one compressible element is assembled in the battery cell housing, and the at least one compressible element is configured to counteract any bulging of the battery cell.

13. The method of claim 12, further comprising preloading the at least one compressible element.

14. A method for manufacturing a battery for a vehicle, comprising: To manufacture a plurality of battery cells according to claim 12 or 13; as well as The multiple battery cells are assembled together.

15. An apparatus for manufacturing a battery cell, comprising: A loading device for preloading compressible elements; as well as An assembly apparatus for assembling the compressible element into a battery cell housing.

Images