Battery module, battery pack and vehicle comprising the same

Abstract

A battery module according to one embodiment of the disclosure includes a battery cell stack including a plurality of battery cells, and a module case including a bottom plate covering a lower surface of the battery cell stack, a cover plate covering an upper surface of the battery cell stack, and a connector connecting the bottom plate and the cover plate, and accommodating the battery cell stack, wherein the bottom plate and the cover plate have a curved shape such that a central region thereof is closer to the battery cell stack than an edge region.

Description

Technical Field

[0001] This disclosure relates to a battery module having a structure capable of applying uniform pressure when expansion occurs, as well as a battery pack and a vehicle including the battery module. More specifically, this disclosure relates to a battery module including a module housing with structural modifications to prevent pressure from concentrating only in the central region of the battery cells when expansion occurs, as well as a battery pack and a vehicle including the battery module.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0020137, filed in Korea on February 15, 2021, the disclosure of which is incorporated herein by reference. Background Technology

[0003] like Figure 1 As shown, a conventional battery module includes: a stack of battery cells, comprising battery cells 100 and expansion absorption pads 200; and a module housing 300 housing the stack of battery cells. In the conventional battery module, the upper plate 300a and the lower plate 300b of the module housing 300 have a generally flat shape.

[0004] When the upper plate 300a and lower plate 300b of the module housing 300 have this flat shape, the upper plate 300a and lower plate 300b bend upward and downward respectively as the battery cell 100 expands.

[0005] Due to the bending of the upper plate 300a and the lower plate 300b, the pressure exerted by the upper plate 300a and the lower plate 300b on the battery cell 100 is relatively small in the middle region of the battery cell 100 and relatively strong as it approaches the edge region.

[0006] Therefore, when the gas generated in the battery cell 100 is concentrated in the central region of the battery cell 100, the separator constituting the electrode assembly will exhibit wrinkles. The separator is a component used to prevent the movement of electrons, thereby accelerating the deterioration of the battery cell 100.

[0007] In addition, when the pressure is concentrated on the edge area of ​​the battery cell 100, the amount of expansion caused by the expansion in the central area is too large, which can cause the soft-pack module shell to tear.

[0008] Therefore, it is necessary to develop a battery module with the following structure: the deviation of the pressure applied to the battery cell due to expansion is resolved, and the bending stiffness of the module shell at the position corresponding to the middle region of the battery cell is improved. Summary of the Invention

[0009] Technical issues

[0010] This disclosure is designed to solve the problems of the related technology. Therefore, this disclosure aims to provide a battery module housing with the following structure: the deviation of the pressure applied to the battery cell due to expansion is solved, and the bending stiffness of the module housing at the position corresponding to the middle region of the battery cell is improved.

[0011] However, the technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of this disclosure other problems not mentioned herein.

[0012] Technical solution

[0013] In one aspect of this disclosure, a battery module is provided, comprising: a battery cell stack including a plurality of battery cells; and a module housing including a base plate covering a lower surface of the battery cell stack, a cover plate covering an upper surface of the battery cell stack, and a connector connecting the base plate and the cover plate, wherein the module housing accommodates the battery cell stack, wherein the base plate and the cover plate have curved shapes such that their central regions are closer to the battery cell stack than their edge regions.

[0014] The battery cell stack may also include a pair of expansion absorption pads, which are disposed on the outermost sides of the battery cell stack along the stacking direction.

[0015] The pair of expansion absorbent pads may each have a shape in which the thickness of the central region is thinner than the thickness of the edge region.

[0016] The pair of expansion absorbent pads may each have a stepped shape, such that the surfaces facing the base plate and the cover plate decrease from the edge region toward the center region.

[0017] The pair of expansion absorbent pads may each have a curved shape, such that the surfaces facing the base plate and the cover plate are in full contact with the base plate and the cover plate.

[0018] The connector may include an elongation portion having a relatively higher elongation rate than the surrounding area.

[0019] The elongated portion may correspond to a region made of metal with a relatively higher elongation rate compared to the surrounding region.

[0020] The elongated portion may correspond to a region that is thinner than the surrounding area.

[0021] Meanwhile, in another aspect of this disclosure, a battery pack is provided, including a battery module according to an embodiment of this disclosure.

[0022] In another aspect of this disclosure, a vehicle is provided that includes a battery pack according to one embodiment of this disclosure.

[0023] Beneficial effects

[0024] According to one aspect of this disclosure, deviations in pressure applied to a battery cell due to expansion can be resolved, and the bending stiffness of the module housing at the location corresponding to the central region of the battery cell can be increased. Attached Figure Description

[0025] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are intended to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0026] Figure 1 This is a diagram showing a conventional battery module.

[0027] Figures 2 to 5 This is a diagram illustrating a battery module according to an embodiment of the present disclosure.

[0028] Figure 6 and Figure 7 This is a diagram illustrating the deformation of the module housing due to expansion in a battery module according to an embodiment of the present disclosure.

[0029] Figure 8 and Figure 9 This is a diagram illustrating various shapes of the expansion absorption pad in a battery module according to an embodiment of the present disclosure.

[0030] Figures 10 to 12 This is a diagram illustrating a battery module according to another embodiment of the present disclosure.

[0031] Figure 13 and Figure 14 This is a diagram illustrating a battery module according to yet another embodiment of the present disclosure.

[0032] Figure 15 This is a diagram illustrating a battery pack according to an embodiment of the present disclosure.

[0033] Figure 16 This is a diagram illustrating a vehicle according to an embodiment of the present disclosure. Detailed Implementation

[0034] The preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. Before the description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its conventional and dictionary meanings, but rather as being understood based on the principle that the inventors can appropriately define the terms for best description, and on their corresponding meanings and concepts in relation to the technical aspects of this disclosure. Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes and are not intended to limit the scope of this disclosure. It should be understood that other equivalent substitutions and modifications can be made without departing from the scope of this disclosure.

[0035] Reference Figures 2 to 7 A battery module 1 according to an embodiment of the present disclosure is described. (Refer to...) Figures 2 to 7 According to one embodiment of the present disclosure, the battery module 1 includes a battery cell stack 10 and a module housing 20.

[0036] The battery cell stack 10 includes a plurality of battery cells 11. For example, a pouch cell can be used as the battery cell 11. Each battery cell 11 includes a pair of electrode leads 11a extending along its length (parallel to the X-axis) to the outside of the battery cell 11. The pair of electrode leads 11a can be led out in the same or opposite directions. The plurality of battery cells 11 are stacked and face each other in a vertical direction (parallel to the Z-axis).

[0037] The battery cell stack 10 may further include a pair of expansion absorption pads 12 disposed on the outermost sides of the battery cell stack 10 along the stacking direction (parallel to the Z-axis). In addition to being disposed on the outermost sides of the battery cell stack 10 along the stacking direction, the expansion absorption pads 12 may be disposed between adjacent battery cells 11. When the battery cell 11 expands due to repeated charging / discharging, the expansion absorption pads 12 can be compressed to absorb the volume expansion of the battery cell 11.

[0038] The expansion absorbent pad 12 can have the same as Figure 1 The expansion absorber 200 shown has a flat shape similar to that provided in a conventional battery module, but it can also have a shape corresponding to the curved shape of the module housing 20 as described below. The specific shape of the expansion absorber 12 will be described in detail after the description of the module housing 20 in this disclosure.

[0039] The module housing 20 includes a base plate 21, a cover plate 22, and a connector 23. The battery cell stack 10 is housed within the module housing 20. The module housing 20 may be made of metallic material to ensure rigidity.

[0040] The base plate 21 covers the lower surface (parallel to the XY plane) of the battery cell stack 10. The cover plate 22 covers the upper surface (parallel to the XY plane) of the battery cell stack 20. The connector 23 connects the base plate 21 and the cover plate 22.

[0041] The connector 23 can be integrally formed with the base plate 21 and / or the cover plate 22. Alternatively, the connector 23 can be formed separately from the base plate 21 and / or the cover plate 22, and can be fixed to the base plate 21 and / or the cover plate 22 by means of welding, bolting or other methods.

[0042] like Figure 2 and Figure 3As shown, connector 23 may have a shape including a side plate forming the side of module housing 20. On the other hand, as Figure 4 and Figure 5 As shown, connector 23 can have a rod-shaped or beam-shaped form for connecting and securing base plate 21 and cover plate 22. In this case, connector 23 can be secured to the four corner regions of each of base plate 21 and cover plate 22.

[0043] The base plate 21 and the cover plate 22 have curved shapes, such that their central regions are closer to the battery cell stack 10 than their edge regions. The accompanying drawings of this disclosure only show the cases where the expansion absorption pad 12 is inserted between the base plate 21 and the battery cell 11, and between the cover plate 22 and the battery cell 11, respectively. However, this disclosure is not limited to this and also includes cases where the expansion absorption pad 12 is not provided.

[0044] Reference Figure 6 and Figure 7 When the battery cell 11 expands, due to the curved shape of the base plate 21 and the cover plate 22, the central region of the battery cell 11 contacts the base plate 21 and the cover plate 22 before its edge regions. Therefore, the central region of the battery cell 11 is pressurized first until the battery cell 11 undergoes a volume expansion of more than a predetermined level due to expansion. When the battery cell 11 has a volume expansion of more than a predetermined level due to expansion, the edge regions of the battery cell 11 also contact the base plate 21 and the cover plate 22, thereby enabling pressure to be applied to the entire region of the battery cell 11.

[0045] Meanwhile, when the battery module 1 according to one embodiment of the present disclosure includes a pair of expansion absorption pads 12 located on the outermost sides of the battery cell stack 10 along the stacking direction, the pair of expansion absorption pads 12 may each have a shape in which the thickness of the central region is thinner than the thickness of the edge region. In this case, the contact area between the battery cell stack 10 and the base plate 21 and the contact area between the battery cell stack 10 and the cover plate 22 can be increased. Therefore, when volume expansion occurs due to the expansion of the battery cell 11, uniform pressure can be applied over the entire area of ​​the battery cell 11.

[0046] Reference Figures 2 to 8 The pair of expansion-absorbing pads 12 may each have a stepped shape, such that the surfaces facing the base plate 21 and the cover plate 22 gradually decrease from the edge region towards the center region. The stepped shape formed on the expansion-absorbing pads 12 can provide, for example... Figures 2 to 7 A stepped structure as shown, or as Figure 8 The diagram shows multiple stepped structures.

[0047] Reference Figure 9 ,and Figures 2 to 8As shown, a pair of expansion absorbent pads 12 have curved shapes with their surfaces facing the base plate 21 and the cover plate 22 in complete contact with the base plate 21 and the cover plate 22, respectively.

[0048] As described above, a battery module 1 according to an embodiment of the present disclosure includes a base plate 21 and a cover plate 22 having curved shapes, and optionally includes an expansion absorption pad 12 having a shape corresponding to the base plate 21 and the cover plate 22, so that uniform pressure can be applied over the entire area of ​​the battery cell 11 when expansion occurs.

[0049] Next, we will refer to Figures 10 to 14 A battery module 1 according to another embodiment of the present disclosure is described. The battery module 1 according to another embodiment of the present disclosure may include the same features as the battery module 1 according to the foregoing embodiment, except that, compared to the electrode module 1 according to the foregoing embodiment, an extension 23a is provided in the connector 23. Therefore, when describing the battery module 1 according to another embodiment of the present disclosure, the connector 23 can be described in detail, and descriptions repeated in the foregoing embodiments can be omitted.

[0050] Reference Figures 10 to 14 The connector 23 includes an elongated portion 23a having a relatively higher elongation rate than the surrounding area. For example... Figures 10 to 12 As shown, the elongated portion 23a can correspond to a region made of metal having a relatively higher elongation rate than the surrounding region. On the other hand, as... Figure 13 and Figure 14 As shown, the elongated portion 23a can correspond to a region that is formed thinner than the surrounding region.

[0051] When the pressure caused by expansion puts a downward force on the base plate 21 and an upward force on the cover plate 22, the connector 23 will slightly elongate when a tensile force exceeding a predetermined level is applied to it. This elongation of the extension 23a prevents excessive increase in pressure applied to the battery cell 11. The metal material constituting the extension 23a and / or the thickness of the extension 23a can be appropriately selected based on the magnitude of the expansion pressure of the battery cell 11.

[0052] As described above, in addition to the structure in which pressure caused by expansion can be uniformly applied to the entire area of ​​the battery cell 11, the battery module 1 according to another embodiment of the present disclosure may have a structure in which the connector 23 can slightly elongate when a tensile force exceeding a predetermined level is applied. Therefore, in the battery module 1 according to another embodiment of the present disclosure, damage to the battery cell 11 due to excessive pressure applied to the battery cell 11 can be prevented.

[0053] Reference Figure 15According to one embodiment of the present disclosure, the battery pack 3 includes at least one battery module 1 according to the present disclosure. The battery pack 3 may have a shape in which the battery module 1 is housed in the battery pack housing 2.

[0054] At the same time, refer to Figure 16 The vehicle 4 according to one embodiment of the present disclosure includes the battery pack 3 according to one embodiment of the present disclosure as described above. The vehicle 4 may be, for example, an electric vehicle powered by electricity from the battery pack 3.

[0055] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples given are by way of illustration only, indicating preferred embodiments of the present disclosure, and various changes and modifications within the scope of the present disclosure will be apparent to those skilled in the art based on the detailed description.

[0056] [Figure Labels]

[0057] 1: Battery Module

[0058] 2: Battery pack casing

[0059] 3: Battery pack

[0060] 4: Vehicles

[0061] 10: Battery cell stack

[0062] 11: Battery cell

[0063] 12: Expansion Absorption Pad

[0064] 20: Module casing

[0065] 21: Base Plate

[0066] 22: Cover plate

[0067] 23: Connector

[0068] 23a: Elongation

Claims

1. A battery module, comprising: A battery cell stack, wherein the battery cell stack comprises multiple battery cells; as well as The module housing includes a base plate covering the lower surface of the battery cell stack, a cover plate covering the upper surface of the battery cell stack, and a connector connecting the base plate and the cover plate, and the module housing accommodates the battery cell stack. The base plate and the cover plate have curved shapes, such that their central regions are closer to the battery cell stack than their edge regions. The battery cell stack further includes a pair of expansion absorption pads disposed along the stacking direction on the outermost sides of the battery cell stack and respectively located between the battery cell stack and the base plate and between the battery cell stack and the cover plate. The pair of expansion absorbent pads each have a shape in which the thickness of the central region in the length direction is thinner than the thickness of the edge region in the length direction.

2. The battery module according to claim 1, in, The pair of expansion absorbent pads each have a stepped shape, such that the surfaces facing the base plate and the cover plate decrease from the edge region toward the central region.

3. The battery module according to claim 1, in, The pair of expansion absorbent pads each have a curved shape, such that the surfaces facing the base plate and the cover plate are in complete contact with the base plate and the cover plate.

4. The battery module according to claim 1, in, The connector includes an elongated portion having a relatively higher elongation rate than the surrounding area.

5. The battery module according to claim 4, in, The elongated portion corresponds to a region made of metal having a relatively higher elongation rate compared to the surrounding region.

6. The battery module according to claim 4, in, The elongated portion corresponds to a region that is formed to be thinner than the surrounding region.

7. A battery pack comprising a battery module according to any one of claims 1 to 6.

8. A vehicle comprising the battery pack according to claim 7.

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