Battery cell, battery module, and battery pack and vehicle including same

Abstract

Disclosed are a battery cell packaged by a packaging material, a battery module, and a battery pack and a vehicle including the battery module. The encapsulation material includes an aluminum layer and a polymer layer. The encapsulation material has a graphite layer on the aluminum layer or on the polymer layer or between the aluminum layer and the polymer layer.

Description

Technical Field

[0001] This disclosure relates to a battery cell, a battery module, a battery pack including the battery module, and a vehicle, which prevents battery cell degradation and improves performance by addressing thermal imbalance in the battery cell and achieving thermal balance, and improves battery cell safety by preventing heat concentration in specific areas. Background Technology

[0002] Recently, carbon reduction technologies have been actively developed to address environmental issues such as abnormal temperatures. These technologies aim to reduce carbon emissions by generating energy in an environmentally friendly manner, rather than using fossil fuels. This energy will be stored as electricity and used in vehicles, various industrial sites, and homes.

[0003] To utilize electricity for carbon reduction, it is necessary to use batteries that store and draw energy from it. Therefore, ensuring battery performance is essential for both the efficient storage and convenient use of electrical energy.

[0004] Batteries primarily utilize the reduction-oxidation reaction of metal ions and employ high-density metal ion usage to increase capacity, charge / discharge performance, and efficiency. Furthermore, significant research has been conducted on the materials constituting the electrolyte and solid electrolyte. However, as battery performance typically improves, a decrease in stability often arises.

[0005] Batteries used in vehicles, industry, and homes are manufactured using physical units called battery packs. A battery pack contains multiple individual battery cells embedded inside a battery casing, and these cells are sealed to prevent flames from spreading to the outside in the event of an accident (such as battery thermal runaway), and to protect the internal battery cells from degradation caused by external environmental factors or damage due to physical causes.

[0006] In a battery pack, multiple battery cells are mounted in an intermediate form, called a module or assembly (CMA). In the case of a module or assembly, multiple battery cells are assembled into a single module or assembly, and these modules are secured inside the battery pack housing to complete the battery pack. Maintenance of the battery is performed on a module or assembly basis, facilitating maintenance.

[0007] A module or assembly consists of multiple individual battery cells, including a positive electrode, a negative electrode, and an electrolyte. Since individual battery cells generate heat during charging and discharging, effective heat dissipation is necessary. Furthermore, from the perspective of battery modules, assemblies, or battery packs, effective heat dissipation design is required to prevent safety accidents.

[0008] On the other hand, batteries can deteriorate due to manufacturing errors, overcharging and discharging, and aging. Furthermore, if battery deterioration continues, it can eventually lead to a fire. Therefore, it is necessary to take precautions to prevent fires from occurring in batteries.

[0009] Therefore, batteries need to be cooled by a cooling system to cool battery modules or components, and from the perspective of the individual battery cells that make up the modules or components, temperature balance must be performed as a whole.

[0010] The description of the relevant technology is provided only to help understand the background of this disclosure and should not be considered as corresponding to relevant technologies known to a person skilled in the art. Summary of the Invention

[0011] Technical issues According to embodiments of the present disclosure, the present disclosure provides a battery cell, a battery module, a battery pack including the battery module, and a vehicle that can improve the performance and safety of the battery cell by performing thermal balancing of the battery cell.

[0012] The technical problems to be solved in this disclosure are not limited to those described above, and other technical problems not mentioned can be clearly understood by those skilled in the art based on the following description.

[0013] Technical solution To achieve the above objectives, the battery cell according to this disclosure is encapsulated by an encapsulation material comprising an aluminum layer and a polymer layer, wherein the encapsulation material includes a graphite layer located on the aluminum layer, on the polymer layer, or between the aluminum layer and the polymer layer.

[0014] The graphite layer of the encapsulation material can be in close contact with the aluminum layer.

[0015] In the encapsulation material, the aluminum layer can be located outside the polymer layer, and the graphite layer can be located outside the aluminum layer.

[0016] The encapsulation material can be formed by further bonding a graphite layer to the outside while the polymer layer and aluminum layer are integrally molded.

[0017] In the encapsulation material, the graphite layer can be placed at a position corresponding to the side of the battery cell.

[0018] A heat insulation layer can be provided on the outermost side of the encapsulation material.

[0019] The encapsulation material can be formed by further bonding a graphite layer to the outside of the integrally formed polymer layer and aluminum layer. The graphite layer can be bent multiple times and bonded to surround the battery cell. A heat insulation layer can be provided on the outside of the graphite layer at a position corresponding to the side of the battery cell.

[0020] The battery module according to this disclosure includes: a first battery cell, the first battery cell being encapsulated by a first encapsulation material including an aluminum layer and a polymer layer; and a second battery cell, the second battery cell being encapsulated by a second encapsulation material including an aluminum layer and a polymer layer, wherein the encapsulation material includes a graphite layer located on the aluminum layer or on the polymer layer or between the aluminum layer and the polymer layer, wherein the first battery cell and the second battery cell are adjacent to each other.

[0021] A pair of first battery cells can be located adjacent to each other between a pair of second battery cells.

[0022] A pair of first cell cells can be adjacent to each other with graphite sheets between them.

[0023] Each of the second battery cells may have a compression pad installed on its outer side.

[0024] The second battery cell can be located between a pair of first battery cells.

[0025] Each of the first battery cells may have a compression pad on its outer side.

[0026] A graphite sheet may be placed between the compression pad and the first battery cell.

[0027] At least one first battery cell and at least one second battery cell can constitute a battery cell group, and compression pads can be provided on the outer sides of both sides of the battery cell group.

[0028] A graphite sheet may be disposed between the compression pad and the adjacent first battery cell.

[0029] Compression pads may include a heat insulation layer.

[0030] The battery pack and vehicle according to this disclosure include the aforementioned battery module.

[0031] Beneficial effects According to the battery cell, battery module, battery pack and vehicle including the battery module disclosed herein, self-thermal balancing can be performed in the battery cell included in the module or component, thereby improving the efficiency of overall thermal management and improving performance and stability.

[0032] In addition, since thermal equilibrium can be performed in a single battery cell, the efficiency of overall thermal management can be improved, and performance and stability can be significantly improved when using existing cooling systems as is.

[0033] In addition, by effectively using the graphite sheets required to perform thermal balancing for each battery cell, manufacturing costs can be reduced and labor hours (M / H) can be significantly reduced.

[0034] The effects obtained from this disclosure are not limited to those described above, and other effects not mentioned can be clearly understood by those skilled in the art based on the following description. Attached Figure Description

[0035] Figure 1 This is a cross-sectional view of the packaging material of a battery cell according to an embodiment of the present disclosure.

[0036] Figure 2 This is a diagram illustrating a battery cell according to an embodiment of the present disclosure.

[0037] Figure 3 This is a cross-sectional view of the encapsulation material of a battery cell according to another embodiment of the present disclosure.

[0038] Figure 4 This is a diagram illustrating a battery cell according to another embodiment of the present disclosure.

[0039] Figure 5 yes Figure 4 The image shows a cross-sectional view of a single battery cell.

[0040] Figure 6 This is a structural diagram of a battery module according to an embodiment of the present disclosure.

[0041] Figure 7 This is a structural diagram of a battery module according to another embodiment of the present disclosure.

[0042] Figure 8 This is a diagram illustrating the compression pad of a battery module according to an embodiment of the present disclosure.

[0043] Figure 9 yes Figure 8 A cross-sectional view of the compression pad.

[0044] Figure 10 This is a diagram showing a battery pack and a vehicle that utilize the battery cells disclosed herein. Detailed Implementation

[0045] In describing this disclosure, detailed descriptions of relevant known functions or constructions are omitted if they are deemed unnecessarily obscuring the spirit of the disclosure. The accompanying drawings are intended to facilitate understanding of this disclosure and should not be construed as limiting the scope of the drawings. Furthermore, this disclosure is not limited to any particular form but includes all modifications, equivalents, and substitutions without departing from the scope and spirit of the disclosure.

[0046] It should be understood that although the terms first, second, etc., may be used in this document to describe individual elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0047] Unless the context clearly indicates otherwise, the singular forms “a,” “one,” and “the” are intended to include the plural forms as used herein.

[0048] It should also be understood that when the terms “comprising,” “including,” “containing,” and / or “having” are used herein, they specify the presence of the said feature, integer, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0049] In the following description, suffixes such as “module,” “part,” or “unit” are used to refer to elements only for the convenience of interpreting this disclosure, and have no special meaning in themselves.

[0050] When referring to a first element being "connected" or "electrically connected" to a second element, the first element may be directly connected or directly electrically connected to the second element; however, it should be understood that a third element may be present in between. On the other hand, when referring to a first element being "directly connected" or "directly electrically connected" to a second element, it should be understood that there is no third element present in between.

[0051] Figure 1 This is a cross-sectional view of the packaging material of a battery cell according to an embodiment of the present disclosure. Figure 2 This is a diagram illustrating a battery cell according to an embodiment of the present disclosure. Figure 3 This is a cross-sectional view of the packaging material of a battery cell according to another embodiment of the present disclosure. Figure 4 This is a diagram illustrating a battery cell according to another embodiment of the present disclosure. Figure 5 yes Figure 4 The cross-sectional view of the battery cell shown in the image. Figure 6 This is a structural diagram of a battery module according to an embodiment of the present disclosure. Figure 7 This is a structural diagram of a battery module according to another embodiment of the present disclosure. Figure 8 This is a diagram illustrating the compression pad of a battery module according to an embodiment of the present disclosure. Figure 9 yes Figure 8 A cross-sectional view of the compression pad. Figure 10 This is a diagram showing a battery pack and a vehicle that utilize the battery cells disclosed herein.

[0052] In the following description, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. Regardless of the reference numerals, the same parts are given the same reference numerals, and redundant descriptions will be omitted.

[0053] The temperature of individual battery cells rises during charging and discharging, leading to a decrease in battery performance and lifespan. Therefore, cooling structures are needed to continuously maintain the battery cells below a specific temperature. One such structure is a bottom cooling system where coolant flows within the battery pack to cool the bottom of the battery module. However, this cooling method results in a temperature difference between the bottom and top of the battery cells, reducing battery efficiency. To improve this, uniform cooling of the overall temperature of the battery cells is required. In other words, thermal equilibrium is needed not only within the battery module but also within the individual battery cells.

[0054] This disclosure aims to improve fast charging performance and lifespan by effectively balancing the temperature of individual battery cells in a battery module or assembly or battery cell group or stack structure formed by aggregating multiple battery cells, thereby reducing the temperature difference between the locations (top-bottom, side-middle) of the battery cells.

[0055] This disclosure aims to address the problem of position-induced temperature differences that exist even in a single battery cell by adding thin-film thermally conductive materials between battery cells in structures such as stacks, components, modules, and groups of multiple battery cells, thereby reducing the temperature difference in the planar direction of the battery cells.

[0056] Battery cells can be classified as prismatic cells, cylindrical cells, or pouch cells formed from canisters. The various encapsulation materials for these cells are primarily made of aluminum. In this disclosure, the encapsulation materials for these cells utilize thin-film graphite sheets or graphite layers, which are lightweight, thin, and possess excellent thermal conductivity, even superior to that of aluminum. This disclosure aims to suppress heat transfer between adjacent battery cells by applying graphite layers or sheets in various ways and additionally adding heat-insulating baffles to the compression pad, thereby ensuring thermal balance within the battery cell and preventing flame propagation between battery cells.

[0057] According to this disclosure, multiple battery cells can be stacked to form a stack, module, or group. In this disclosure, such a group of battery cells is collectively referred to as a battery module. Therefore, a battery module according to this disclosure should be interpreted as a group of multiple battery cells, such as a stack, module, or group. Furthermore, a battery pack should be understood to include at least one battery module.

[0058] Figure 1A cross-sectional structure of the encapsulation material of a battery cell according to an embodiment of the present disclosure is shown. The battery cell according to the present disclosure may include: an electrode assembly 10, the electrode assembly 10 including a positive electrode, a negative electrode, and an electrolyte; and an encapsulation material 100 surrounding and protecting the electrode assembly 10. Furthermore, the encapsulation material 100 needs to be formed of a material that prevents moisture or foreign matter penetration to prevent short circuits and allows heat exchange with the outside while preventing flame propagation.

[0059] The battery cell encapsulation material 100 disclosed herein may include an aluminum layer 120 and a polymer layer 110. Additionally, a graphite layer 130 may be disposed on one side of the aluminum layer 120, one side of the polymer layer 110, or between the aluminum layer 120 and the polymer layer 110. Figure 1 As shown, a polypropylene (PP) layer is disposed on the innermost side as a polymer. Furthermore, an aluminum layer 120 is disposed on the polymer layer 110. The aluminum layer 120 maintains the rigidity of the encapsulation material 100 and conducts heat, while the inner PP layer 110 is responsible for insulation. Various aluminum alloys, besides pure aluminum, can be used to form the aluminum layer 120.

[0060] The outer side of the aluminum layer 120 is in direct contact with the graphite layer 130. Unlike aluminum, graphite is a material with excellent thermal conductivity in the width direction rather than the thickness direction. Therefore, aluminum is positioned close to the electrode assembly of the battery to ensure heat dissipation and thermal conductivity are achieved first, and graphite is applied on top of it to address the temperature imbalance in the planar direction of aluminum. Thus, through aluminum and graphite, the battery cell can ensure both thermal conductivity and thermal balance in the planar direction. To insulate and protect the graphite layer 130, a nylon layer 140 and a polyethylene terephthalate (PET) layer 150 are bonded on the outer side to form the encapsulation material 100.

[0061] Figure 1 The embodiment shown illustrates a cross-sectional structure of an encapsulation material with a graphite layer 130 disposed after a polymer layer 110 and an aluminum layer 120, and these layers are integrally formed to form a single encapsulation material 100. In this case, the graphite layer 130 of the encapsulation material 100 is configured to be in close contact with the aluminum layer 120, thereby transferring heat from the aluminum layer 120 in the planar direction to achieve planar balance.

[0062] Figure 2 A battery cell is shown as an example of applying this type of encapsulation material 100. Figure 2 The battery cell is a prismatic battery cell, and this refers to a type of battery cell in which an electrode assembly 10 is inserted into a prismatic can having an internal space and is sealed with a cap 30. In this case, the prismatic encapsulation material 100 is made of... Figure 1The encapsulation material is formed to ensure thermal balance in the planar direction. Alternatively, as shown, in the case of graphite layer 130, it may be possible to partially apply graphite layer 130 to a relatively large area only in the portion of the encapsulation material forming the surface other than the corner portions.

[0063] on the other hand, Figure 3 Another example of the encapsulation material is shown. In this case, firstly, polymer layer 110 and aluminum layer 120 are stacked, then polymer layers of nylon 140 and PET 150 are stacked, followed by bonding graphite layer 130 to the outermost layer. That is, in this case, a battery cell is formed from encapsulation material consisting only of polymer layers 110, 140, and 150 and aluminum layer 120, and then graphite layer 130 is bonded to the outer side of the encapsulation material through an additional operation. In this case, graphite layer 130 is separated from aluminum layer 120 by PET layer 150 and nylon layer 140, thereby achieving electrical insulation and performing thermal conduction in the planar direction, thereby achieving thermal equilibrium.

[0064] When the graphite layer 130 is formed together with the encapsulation material 100, the bonding process can be eliminated, which makes manufacturing easier. When the graphite layer 130 is bonded separately, the encapsulation material without the graphite layer can be properly mixed with the encapsulation material with the graphite layer, which can reduce material, reduce weight and increase energy density.

[0065] On the other hand, a heat insulation layer 160 may be additionally bonded to the outer side of the graphite layer 130. The heat insulation layer 160 may include a MICA layer. The MICA layer may have mica as the main component to perform heat insulation and effectively prevent flame propagation. However, since the heat insulation layer 160 may have lower formability compared to polymers, this separate bonding method is considered. By applying the heat insulation layer 160 together, the battery cell can simultaneously achieve planar thermal equilibrium and flame blocking.

[0066] Figure 4 An embodiment is shown in which the graphite layer 130 is additionally bonded to the outer side while the polymer layer and aluminum layer are integrally formed into an encapsulation material. In the encapsulation material, the graphite layer 130 may be disposed at a position corresponding to the side of the battery cell 20, and the heat insulation layer 160 may be disposed on the outermost side, such as... Figure 5 As shown. Specifically, in the encapsulation material 100, in a state where the polymer layer and the aluminum layer are integrally formed, the graphite layer 130 can be additionally bonded to the outside, the graphite layer 130 can be bent multiple times and bonded to surround the battery cell 20, and the heat insulation layer 160 can be disposed on the outside of the graphite layer 130 at a position corresponding to the side of the battery cell.

[0067] Figure 4The casing is a soft-pack battery cell 20 with a graphite layer 130 bonded to the outside of the encapsulation material. Furthermore, as... Figure 5 As shown, by adding the heat insulation layer 160 to the side of the battery cell other than the bottom, thermal balance, flame blocking and heat propagation blocking are achieved on the side at the same time without impairing heat dissipation through the bottom of the battery cell 20.

[0068] Figure 6 and Figure 7 A battery module using such individual battery cells is shown. As mentioned above, a battery module is a group of multiple individual battery cells, and is a concept that encompasses concepts such as stacks, components, and groups.

[0069] The battery module according to this disclosure includes a first battery cell 20 encapsulated with an encapsulation material comprising an aluminum layer and a polymer layer, and a second battery cell 20' encapsulated with an encapsulation material comprising an aluminum layer and a polymer layer, wherein the encapsulation material includes a graphite layer 130 disposed on or between the aluminum layer and the polymer layer. That is, a conventional battery cell in which the encapsulation material does not employ a graphite layer can be defined as the first battery cell 20, and a battery cell in which the encapsulation material employs a graphite layer can also be defined as the first battery cell 20. The battery module of this disclosure aims to effectively utilize graphite by appropriately mixing and arranging the first battery cell 20 and the second battery cell 20', thereby reducing weight and cost, while simultaneously achieving performance equivalent to that of applying graphite to the entire module in terms of thermal balance.

[0070] Specifically, a battery cell pack refers to multiple battery cells clustered together between compression pads, and Figure 6 This is the case where the number of individual battery cells in the group is 4. Figure 7 This is the case where there are 3 battery cells. In addition, each battery cell performs basic heat dissipation through its bottom by contacting the cooling unit 50.

[0071] In both cases, the first battery cell 20 and the second battery cell 20' are arranged adjacent to each other. By arranging the first battery cell 20 and the second battery cell 20' in a mixed manner, the first battery cell 20, excluding the graphite layer, achieves thermal equilibrium in the planar direction by utilizing the graphite layer 130 of the adjacent second battery cell 20'. Therefore, the first battery cell excluding the graphite layer is configured to contact the second battery cell 20' including the graphite layer 130, thereby omitting graphite in a portion and reducing cost and weight. In addition, since the graphite layer is omitted in a portion, the overall energy density of the battery module can be increased.

[0072] Specifically, such as in Figure 6In this case, a pair of first battery cells 20 can be arranged adjacent to each other between a pair of second battery cells 20'. Furthermore, a pair of first battery cells 20 facing and in contact with each other between a pair of second battery cells 20' can be arranged adjacent to each other with a graphite sheet 300 located therebetween. In this way, the first battery cells 20 disposed in the middle share the graphite layer 130 of the second battery cells 20' on one side to achieve thermal equilibrium, and share a separately added graphite sheet 300 on the other side to achieve thermal equilibrium. Figure 3 As shown, a heat insulation layer 160 is added to the graphite layer 130 and the graphite sheet 300 to prevent the spread of heat or flame.

[0073] On the other hand, Figure 7 In this case, the second battery cell 20' is located between a pair of first battery cells 20. In this case, the graphite layer 130 included in the middle second battery cell 20' is shared, and the first battery cells 20 located on opposite sides perform thermal equilibrium together.

[0074] Furthermore, a compression pad 500 is provided on the outer side of each first battery cell 20, and a graphite sheet 300 can be disposed between the compression pad 500 and the first battery cell 20. Therefore, the first battery cell 20 achieves thermal equilibrium by sharing the graphite layer 130 of the second battery cell 20' on one side, and by separately adding the graphite sheet 300 on the other side. Figure 3 As shown, the heat insulation layer 160 can also be added to the graphite layer 130 and the graphite sheet 300 to prevent the spread of heat or flame.

[0075] on the other hand, Figure 8 and Figure 9 The graphite sheet 300 is shown applied to the compression pad 500. The compression pad 500 is formed of a compressible material and serves to absorb the contraction / expansion caused by the charging / discharging of the battery cells. The graphite sheet 300 can be attached to two opposite sides of the compression pad 500 to achieve thermal equilibrium of adjacent first battery cells 20.

[0076] In addition, the compression pad 500 can be formed to include a heat insulation layer 160 in the middle, so that it can also perform the function of preventing heat diffusion or flame propagation between the battery cells in which the compression pad 500 is arranged.

[0077] exist Figure 10 In the case described, a battery pack BP with a battery module according to the present disclosure and a vehicle V equipped with the battery pack BP are shown. In the case of the present disclosure, thermal equilibrium can be effectively achieved at the battery cell level by applying a graphite layer or graphite sheet to the side of the battery cell or compression pad. Furthermore, heat dissipation is improved by bending the graphite layer or graphite sheet to contact the cooling portion beneath it.

[0078] In addition, because a graphite layer or graphite sheet is bent twice to cover the two opposite sides and the bottom surface of a battery cell, the assembly performance is excellent, and because the compression pad together with the graphite sheet also has a heat insulation layer, the thermal balance of the battery cell can be improved while preventing heat transfer.

[0079] Although the present disclosure has been described above with reference to embodiments, those skilled in the art will understand that various modifications and changes can be made to the present disclosure without departing from the concept and scope of the present disclosure as set forth in the appended claims.

Claims

1. A battery cell, said battery cell being encapsulated by an encapsulation material comprising an aluminum layer and a polymer layer, wherein, The encapsulation material includes a graphite layer located on the aluminum layer, on the polymer layer, or between the aluminum layer and the polymer layer.

2. The battery cell according to claim 1, wherein, The graphite layer of the encapsulation material is in close contact with the aluminum layer.

3. The battery cell according to claim 1, wherein, In the encapsulation material, the aluminum layer is located outside the polymer layer, and the graphite layer is located outside the aluminum layer.

4. The battery cell according to claim 1, wherein, The encapsulation material is formed by further bonding the graphite layer to the outside while the polymer layer and the aluminum layer are integrally formed.

5. The battery cell according to claim 1, wherein, In the encapsulation material, the graphite layer is disposed at a position corresponding to the side of the battery cell.

6. The battery cell according to claim 1, wherein, The outermost layer of the encapsulation material is provided with a heat insulation layer.

7. The battery cell according to claim 1, wherein, The encapsulation material is formed by further bonding a graphite layer to the outside of the integrally formed polymer layer and aluminum layer. The graphite layer is bent multiple times and joined to surround the battery cell, and a heat insulation layer is provided on the outside of the graphite layer at a position corresponding to the side of the battery cell.

8. A battery module, comprising: The first battery cell is encapsulated by a first encapsulation material comprising an aluminum layer and a polymer layer; as well as The second battery cell is encapsulated by a second encapsulation material comprising an aluminum layer and a polymer layer, wherein the encapsulation material includes a graphite layer located on the aluminum layer, on the polymer layer, or between the aluminum layer and the polymer layer. The first battery cell and the second battery cell are adjacent to each other.

9. The battery module according to claim 8, wherein, A pair of first battery cells are located adjacent to each other between a pair of second battery cells.

10. The battery module according to claim 9, wherein, The pair of first battery cells are adjacent to each other with the graphite sheet located therebetween.

11. The battery module according to claim 9, wherein, Each of the second battery cells has a compression pad on its outer side.

12. The battery module according to claim 8, wherein, The second battery cell is located between a pair of first battery cells.

13. The battery module according to claim 12, wherein, Each of the first battery cells has a compression pad on its outer side.

14. The battery module according to claim 13, wherein, A graphite sheet is disposed between the compression pad and the first battery cell.

15. The battery module according to claim 8, wherein, At least one first battery cell and at least one second battery cell constitute a battery cell group, and compression pads are provided on the outer sides of both sides of the battery cell group.

16. The battery module according to claim 15, wherein, A graphite sheet is disposed between the compression pad and the first battery cell adjacent to the compression pad.

17. The battery module according to claim 15, wherein, The compression pad includes an insulation layer.

18. A battery pack comprising the battery module of claim 8.

19. A vehicle comprising the battery module of claim 8.

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