Battery pack and cover for battery pack

Abstract

The present invention provides a battery pack and a cover for a battery pack. A battery pack according to the present invention may include: a pack case in which accommodation space parts, in which multiple battery modules are accommodated, are partitioned, and which has one side open; and a cover which is installed to cover the one side of the pack case and on which a graphene coating layer is formed.

Description

Battery pack and cover for battery pack

[0001] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2023-0184745, dated December 18, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a battery pack and a cover for a battery pack, which can rapidly disperse heat in a cover during a thermal runaway, prevent local heat concentration, and prevent explosion due to gas pressure to prevent flame leakage.

[0003] Secondary batteries typically contain a cathode, anode, and an electrolyte, and generate electrical energy through chemical reactions. Their use is steadily increasing due to their ability to be recharged and discharged. Among these secondary batteries, lithium secondary batteries boast a high energy density per unit weight, making them widely used as power sources for electronic communication devices and as power sources for high-power hybrid and electric vehicles.

[0004] In terms of the form factor of these secondary batteries, demand is growing for square and pouch-type battery cells, which can be applied to products such as mobile phones due to their thin thickness. Regarding battery cell materials, demand is also growing for lithium battery cells, such as lithium-ion batteries and lithium-ion polymer batteries, which boast high energy density, discharge voltage, and output stability.

[0005] Currently, widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these battery cells is approximately 2.5 V to 4.2 V. If a higher output voltage is required, multiple battery cells can be connected in series to form a battery module, and multiple battery modules can be connected to form a battery pack. Furthermore, multiple battery cells can be connected in parallel to form a battery pack depending on the required charge / discharge capacity of the battery pack. Accordingly, the number of battery cells and the electrical connection structure of the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0006] Electric vehicles can be subject to unexpected shocks and vibrations on their battery packs during operation. These shocks and vibrations can cause electrical connections between battery modules to break or the pack case supporting the modules to deform. Therefore, battery packs for electric vehicles require sufficient durability and rigidity to withstand external shocks and vibrations.

[0007] The above battery pack increases durability and rigidity by installing multiple package beams within the battery case. The package beams are installed across the interior of the trays that make up the pack case, and serve as structures that define the space for installing battery modules within the trays. Trays equipped with these pack beams have enhanced impact resistance, making them less susceptible to deformation even under external impact or vibration.

[0008] It is crucial for battery packs containing multiple battery modules to easily dissipate the heat generated by each module. In some cases, the heat generated during the charging and discharging process is not effectively dissipated. This can lead to heat accumulation within the battery modules, which can deteriorate the modules. Accelerated deterioration can lead to fire or explosion. Therefore, high-power, high-capacity battery packs are equipped with cooling and safety devices to cool each battery module.

[0009] When a thermal runaway occurs in a specific battery module, gas and flames are emitted from the battery module. As the gas and flames rise, the cover heats. The gas and flames concentrate heat on specific areas of the cover, and as the cover is locally heated, the ductility of that area increases. The internal pressure of the gas applied to the area of ​​increased ductility may cause the cover to burst or become damaged. This bursting or damage to the cover may allow flames and gases to escape outside the battery pack.

[0010] The background technology of the present invention is disclosed in Korean Patent Publication No. 2021-0127508 (published on October 22, 2021, titled: Battery pack including automatic separation bus bar).

[0011] The present invention has been devised to solve the above-described problems, and aims to provide a battery pack and a cover for a battery pack in which a graphene coating layer can quickly disperse heat applied to the cover.

[0012] The present invention aims to provide a battery pack and a cover for a battery pack that can prevent the cover from being locally softened by heat and thereby prevent the cover from being burst or damaged.

[0013] The present invention aims to provide a pack and a cover for a battery pack that can change the shape of a battery graphene coating layer without using a separate mold.

[0014] The present invention aims to provide a battery pack and a cover for a battery pack in which a center reinforcement part and a side reinforcement part reinforce the rigidity of the cover while being usable as a center venting passage.

[0015] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0016] In order to solve the above-described problem, a battery pack according to the present invention may include: a pack case having a compartment for accommodating a plurality of battery modules and having one side open; and a cover installed to cover one side of the pack case, the cover having a graphene coating layer formed thereon.

[0017] The above graphene coating layer can be formed on the inner surface of the cover.

[0018] The above graphene coating layer can be formed on the entire inner surface of the cover.

[0019] The above cover may have multiple curved reinforcing members formed thereon.

[0020] The cover may have long sides and short sides, and the plurality of reinforcing parts may include a center reinforcing part arranged at the center of the short side direction of the cover and formed along the long side direction of the cover; and a plurality of side reinforcing parts arranged parallel to the short side direction of the cover and arranged in the long side direction of the cover.

[0021] The above center reinforcement portion may be formed to protrude to one side to form a center venting passage.

[0022] The above plurality of side reinforcement parts may protrude to one side to form a plurality of side venting passages and may be connected to the center venting passage.

[0023] The cover may include a cover plate on which the center reinforcement portion and the plurality of side reinforcement portions are formed and the graphene coating layer is formed; and a reinforcing frame laminated on the periphery of the cover plate to reinforce the rigidity of the cover plate.

[0024] The above reinforcing frame may include a plurality of reinforcing panels extending toward the center reinforcing member.

[0025] The above reinforcing panel may have a recessed reinforcing step formed so as to fit tightly between the side reinforcing parts.

[0026] A cover for a battery pack according to the present invention may include: a cover plate on which a graphene coating layer is formed; and a reinforcing frame laminated on a periphery of the cover plate to reinforce the rigidity of the cover plate.

[0027] The above graphene coating layer can be formed on the inner surface of the cover plate.

[0028] The above graphene coating layer can be formed on the entire inner surface of the cover plate.

[0029] The above cover plate has a long side and a short side, and the above cover plate,

[0030] It may include a center reinforcing portion arranged in the center of the short side direction of the cover plate and formed along the long side direction of the cover plate; and a plurality of side reinforcing portions arranged in parallel with the short side direction of the cover plate and arranged in the long side direction of the cover plate.

[0031] The above center reinforcement portion may be formed to protrude to one side to form a center venting passage.

[0032] The above plurality of side reinforcement parts may protrude to one side to form a plurality of side venting passages and may be connected to the center venting passage.

[0033] The above reinforcing frame may include a plurality of reinforcing panels extending toward the center reinforcing member.

[0034] The above reinforcing panel may have a recessed reinforcing step formed so as to fit tightly between the side reinforcing parts.

[0035] According to the present invention, a graphene coating layer is formed on the cover, and the graphene coating layer can rapidly dissipate heat applied to the cover. Accordingly, the cover can be prevented from being locally heated by flames and gases in the event of thermal runaway of a specific battery module.

[0036] According to the present invention, since the graphene coating layer quickly disperses heat applied to the cover, the cover can be prevented from being locally softened by heat, thereby preventing the cover from being burst or damaged.

[0037] According to the present invention, since a graphene coating layer is formed on the cover, no adhesive is used on the cover, and thus the graphene coating layer does not come off from the cover due to heat.

[0038] According to the present invention, since the graphene coating layer is applied to the surface of the cover, a separate mold may not be used to change the shape of the graphene coating layer.

[0039] According to the present invention, the center reinforcement portion can be formed to protrude to one side to form a center venting passage. Accordingly, the center reinforcement portion can be used as a center venting passage while reinforcing the rigidity of the cover.

[0040] According to the present invention, a plurality of side reinforcements protrude to one side to form a plurality of side venting passages, and the plurality of side venting passages are connected to the center venting passage. Accordingly, the plurality of side reinforcements can be used as side venting passages while reinforcing the rigidity of the cover.

[0041] According to the present invention, a reinforcing frame is laminated around the periphery of the cover plate to reinforce the rigidity of the cover plate, thereby preventing gas or flames from leaking out to the edge of the battery pack.

[0042] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0043] Figure 1 is a perspective view schematically illustrating a battery pack according to the present invention.

[0044] FIG. 2 is a perspective view schematically illustrating a pack case of the battery pack of FIG. 1.

[0045] Fig. 3 is a perspective view schematically illustrating a state in which a battery module is accommodated in the pack case of Fig. 2.

[0046] Figure 4 is a perspective view schematically illustrating the cover of the battery pack of Figure 1.

[0047] Figure 5 is an exploded perspective view schematically illustrating the cover of the battery pack of Figure 1.

[0048] Figure 6 is a perspective view schematically illustrating a cover plate constituting the cover of Figure 5.

[0049] Figure 7 is a perspective view schematically illustrating a reinforcing frame constituting the cover of Figure 5.

[0050] Figure 8 is a perspective view schematically illustrating a graphene coating layer constituting the cover of Figure 5.

[0051] [Explanation of symbols]

[0052] 100: Battery pack

[0053] 102: Battery module

[0054] 110: Pack Case

[0055] 111: Barrier

[0056] 112: Reception Space Department

[0057] 113: Chimney Home

[0058] 114: Benting Hall

[0059] 120: Cover

[0060] 121: Cover plate

[0061] 122: Center reinforcement

[0062] 122a: Center venting passage

[0063] 123: Side reinforcement

[0064] 123a: Side venting passage

[0065] 125: Reinforcement frame

[0066] 126: Reinforcement panel

[0067] 127: Reinforcement step

[0068] 128: Graphene coating layer

[0069] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0070] The present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and with various modifications. However, these embodiments are provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Therefore, the present invention is not limited to the embodiments disclosed below, but should be understood to include all modifications, equivalents, and substitutes included within the technical spirit and scope of the present invention, as well as substitutions or additions of the components of one embodiment with those of another embodiment.

[0071] The attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification, but should be understood to encompass all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention. In the drawings, the components may be expressed in exaggerated sizes or thicknesses for ease of understanding, but the scope of protection of the present invention should not be construed as being limited thereby.

[0072] The terminology used in this specification is only used to describe specific implementations or examples and is not intended to limit the present invention. In addition, the singular expression includes the plural expression unless the context clearly indicates otherwise. In the specification, terms such as "comprises" and "consists of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification. In other words, it should be understood that terms such as "comprises" and "consists of" in the specification do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0073] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0074] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0075] When a component is referred to as being "above" or "below" another component, it should be understood that it is not only positioned directly above that other component, but that there may also be other components present in between.

[0076] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0077] Hereinafter, a battery pack according to an embodiment of the present invention will be described.

[0078] FIG. 1 is a perspective view schematically illustrating a battery pack according to the present invention, FIG. 2 is a perspective view schematically illustrating a pack case of the battery pack of FIG. 1, FIG. 3 is a perspective view schematically illustrating a state in which a battery module is accommodated in the pack case of FIG. 2, FIG. 4 is a perspective view schematically illustrating a cover of the battery pack of FIG. 1, and FIG. 5 is an exploded perspective view schematically illustrating a cover of the battery pack of FIG. 1.

[0079] Referring to FIGS. 1 to 5, a battery pack (100) according to an embodiment of the present invention includes a pack case (110). The pack case (110) may be formed entirely of a metallic material.

[0080] The battery module (102) includes a plurality of battery cells (not shown). The plurality of battery cells may be of pouch type, square type, or cylindrical type. The battery module (102) is placed in the corresponding receiving space (112).

[0081] A plurality of barriers (111) are installed inside the pack case (110) to define a receiving space (112) in which a plurality of battery modules (102) are received. The plurality of barriers (111) may be arranged parallel to the short side direction of the pack case (110) and along the long side direction. The plurality of barriers (111) reinforce the rigidity of the pack case (110). The plurality of barriers (111) can prevent gas and flames from flowing to the adjacent receiving space (112) when thermal runaway or thermal runaway transition occurs. One side of the pack case (110) is open. A pack frame is installed to surround the periphery of the pack case (110). Venting holes (114) are formed on the front and rear sides of the pack frame.

[0082] The cover (120) can be installed to cover one side of the pack case (110). The cover (120) is connected to the outer frame of the pack case (110) to define the internal space of the pack case (110). The connection can be achieved by various means such as welding or fastening. A graphene coating layer (128) is formed on the cover (120). The graphene coating layer (128) has a thermal conductivity that is more than twice that of diamond, thereby improving heat transfer efficiency and durability. In addition, since the graphene coating layer (128) quickly disperses heat applied to the cover (120), the cover (120) can be prevented from being locally heated by flames and gases in the event of thermal runaway of a specific battery module (102). Accordingly, the cover (120) can be prevented from being locally softened by heat, thereby preventing the cover (120) from being burst or damaged. Furthermore, it is possible to delay or suppress the discharge of gas and flames to the outside of the battery pack (100) during thermal runaway of the battery pack (100).

[0083] In the past, a mica sheet could be attached to the inner surface of the cover (120) with an adhesive. In this case, when the battery module (102) experiences thermal runaway and heat transfer, the adhesive may melt as the cover (120) is heated, causing the mica sheet to fall off. In addition, since the mica sheet is approximately 1 mm thick, the gas pass space may become relatively narrow. In addition, since reinforcing ribs are formed on the cover (120) to reinforce the rigidity of the cover (120), the shape of the mica sheet must be matched to that of the cover (120) using a mold. In addition, since the mold must be remanufactured when the shape of the cover (120) is changed, the manufacturing cost of the battery pack (100) may increase.

[0084] In contrast, since the present invention forms a graphene coating layer (128) on the cover (120), no adhesive is used on the cover (120), so the graphene coating layer (128) does not come off from the cover (120) due to heat. In addition, since the graphene coating layer (128) is applied to the surface of the cover (120), a separate mold may not be used. In addition, the graphene coating layer (128) may be applied to covers (120) of various shapes. Furthermore, since the thickness of the graphene coating layer (128) is formed very thinly, the gas pass space in the cover (120) becomes relatively wide, and space utilization may be increased.

[0085] The graphene coating layer (128) is formed on the inner surface of the cover (120). The graphene coating layer (128) is formed in steps corresponding to the center reinforcement part (122) and the side reinforcement part (123) of the cover (120) to be described below. At this time, the graphene coating layer (128) can be formed on the entire inner surface of the cover (120). Accordingly, the graphene coating layer (128) can disperse heat throughout the entire cover (120). In FIG. 5, the graphene coating layer (128) is illustrated as being separated from the cover, but this is for the convenience of explanation, and the graphene coating layer (128) is actually a layer coated on the cover (120).

[0086] The cover (120) may be formed in an overall rectangular shape with long and short sides. This cover (120) is formed to correspond to the shape of the pack case (110).

[0087] FIG. 4 is a perspective view schematically illustrating a cover of the battery pack of FIG. 1, FIG. 5 is an exploded perspective view schematically illustrating a cover of the battery pack of FIG. 1, FIG. 6 is a perspective view schematically illustrating a cover plate constituting the cover of FIG. 5, FIG. 7 is a perspective view schematically illustrating a reinforcing frame constituting the cover of FIG. 5, and FIG. 8 is a perspective view schematically illustrating a graphene coating layer constituting the cover of FIG. 5.

[0088] Referring to FIGS. 4 to 8, a plurality of curved reinforcing members (122, 123) may be formed on the cover (120). The plurality of reinforcing members (122, 123) are formed in steps on the cover (120) to increase the structural rigidity of the cover (120).

[0089] The plurality of reinforcing members (122, 123) may include one or more center reinforcing members (122) and a plurality of side reinforcing members (123). When a plurality of battery modules (102) are arranged in two rows in the longitudinal direction inside the battery pack (100), one center reinforcing member (122) may be formed at the center of the short side direction of the battery pack (100). In addition, when a plurality of battery modules (102) are arranged in three or more rows in the longitudinal direction inside the battery pack (100), two or more center reinforcing members (122) may be formed at the center of the short side direction of the battery pack (100).

[0090] The center reinforcement part (122) is arranged at the center of the short side direction of the cover (120) and may be formed parallel to the long side direction of the cover (120). The center reinforcement part (122) may be formed in a straight line. A plurality of side reinforcement parts (123) may be arranged parallel to the short side direction of the cover (120) and may be arranged in the long side direction of the cover (120).

[0091] The center reinforcement member (122) is formed to protrude to one side to form a center venting passage (122a). At this time, a plurality of barriers (111) may have a communication groove (113) formed in a size corresponding to the center reinforcement member (122) at the longitudinal center of the barrier (111). The degree of protrusion of the center reinforcement member (122) and the depth of the communication groove (113) may be determined in consideration of the size of the center venting passage (122a).

[0092] A plurality of side reinforcement parts (123) protrude to one side to form a plurality of side venting passages (123a), and the plurality of side venting passages (123a) are connected to the center venting passage (122a). The plurality of side reinforcement parts (123) are formed in a straight line. At least one side reinforcement part (123) may correspond to one side of each receiving space part (112). Depending on the size of the receiving space part (112), the number of side reinforcement parts (123) corresponding to the corresponding receiving space part (112) may be appropriately changed. Since the plurality of side venting passages (123a) are connected to the center venting passage (122a), gas and flame generated in the battery module (102) can be discharged to the outside of the battery pack (100) through the plurality of side venting passages (123a), the center venting passage (122a), and the venting hole part (114).

[0093] According to the present embodiment, a battery pack (100) is provided in which the structural, mechanical, and thermal stability of the cover (120) are simultaneously strengthened by the graphene coating layer (128) preventing softening of the cover (120) due to a local temperature increase, and the plurality of reinforcing members (122, 123) preventing structural damage to the cover (120).

[0094] In addition, according to the present embodiment, heat is rapidly propagated and dissipated due to the graphene coating layer (128), and gas and flames can be discharged through the venting passages (122a, 123a), thereby preventing thermal runaway, increasing cooling and heat dissipation efficiency, and reducing the risk of explosion, etc., thereby providing a battery pack (100).

[0095] The cover (120) includes a cover plate (121) and a reinforcing frame (125).

[0096] A center reinforcing member (122) and a plurality of side reinforcing members (123) are formed on the cover plate (121), and a graphene coating layer (128) is formed. The cover plate (121) is joined to the periphery of the pack case (110) so as to cover one side of the pack case (110). The joining can be accomplished by various means such as welding or fastening.

[0097] A reinforcing frame (125) is laminated around the periphery of the cover plate (121) to reinforce the rigidity of the cover plate (121). The reinforcing frame (125) may be welded to the cover plate (121) by spot welding, laser welding, or the like. Alternatively, the reinforcing frame (125) may be joined to the cover plate (121) by other means, such as by being fastened thereto. The reinforcing frame (125) reinforces the rigidity of the periphery of the cover (120) to prevent gas or flames from leaking out to the edge of the battery pack (100).

[0098] The reinforcing frame (125) includes a plurality of reinforcing panels (126) extending toward the center reinforcing portion (122). The reinforcing panels (126) extend toward the center reinforcing portion (122) in a trapezoidal shape, a triangular shape, or the like. Since the reinforcing panels (126) are formed in a trapezoidal shape or a triangular shape, it is possible to reinforce the rigidity in the long-side direction of the pack case (110) while preventing the cover (120) from being deformed in the short-side direction of the pack case (110).

[0099] The reinforcing panel (126) may be formed with a recessed reinforcing step portion (127) so as to be in close contact between the side reinforcing portions (123). The plurality of reinforcing step portions (127) are formed in a straight line shape parallel to the short-side direction of the cover plate (121). The plurality of reinforcing step portions (127) can further improve the rigidity of the cover plate (121) in the short-side direction.

[0100] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A pack case having a compartment for accommodating multiple battery modules and having one side open; A cover installed to cover one side of the above pack case and having a graphene coating layer formed thereon; A battery pack, wherein the cover is formed with a plurality of reinforcing parts protruding to one side to form a venting passage.

2. In paragraph 1, A battery pack, wherein the graphene coating layer is formed on the inner surface of the cover.

3. In paragraph 2, A battery pack, wherein the graphene coating layer is formed on the entire inner surface of the cover.

4. In paragraph 1, A battery pack, wherein the plurality of reinforcing members are formed in a curved shape.

5. In paragraph 1, The above cover has long sides and short sides, The above multiple reinforcing parts are, A center reinforcing part arranged in the center of the short side direction of the cover and formed along the long side direction of the cover, forming a center venting passage; and A battery pack comprising: a plurality of side reinforcing members arranged in a direction parallel to the short side of the cover and arranged in a direction of the long side of the cover, the plurality of side venting passages being connected to the center venting passage.

6. In paragraph 5, The above cover, A cover plate on which the center reinforcement part and the plurality of side reinforcement parts are formed and the graphene coating layer is formed; and A battery pack, comprising: a reinforcing frame laminated on a periphery of the cover plate to reinforce the rigidity of the cover plate.

7. In paragraph 6, A battery pack, wherein the reinforcing frame includes a plurality of reinforcing panels extending toward the center reinforcing member.

8. In paragraph 7, A battery pack, wherein the reinforcing panel has a sunken reinforcing step formed between the side reinforcing parts so as to be in close contact with each other.

9. A cover plate on which a graphene coating layer is formed and a plurality of reinforcing parts protruding to one side to form a venting passage are formed; and A cover for a battery pack, comprising: a reinforcing frame laminated on a periphery of the cover plate to reinforce the rigidity of the cover plate.

10. In paragraph 9, A cover for a battery pack, wherein the graphene coating layer is formed on the inner surface of the cover plate.

11. In paragraph 10, A cover for a battery pack, wherein the graphene coating layer is formed on the entire inner surface of the cover plate.

12. In paragraph 9, The above cover plate has a long side and a short side, The above cover plate, A center reinforcing portion formed along the long side of the cover plate and positioned at the center of the short side of the cover plate, forming a center venting passage; and A cover for a battery pack, comprising: a plurality of side reinforcing parts arranged in a direction parallel to the short side of the cover plate and arranged in a direction of the long side of the cover plate, the plurality of side venting passages being connected to the center venting passage; 13. In paragraph 12, A cover for a battery pack, wherein the reinforcing frame includes a plurality of reinforcing panels extending toward the center reinforcing portion.

14. In paragraph 13, A battery pack cover, wherein the reinforcing panel has a sunken reinforcing step formed between the side reinforcing parts so as to be in close contact with each other.

15. A battery pack comprising a cover according to any one of claims 9 to 14.

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