Battery pack and manufacturing method thereof

Abstract

The battery pack of the present invention includes a battery module having a drain hole formed on a bottom surface thereof; a plate having the battery module disposed on an upper surface thereof; a heat sink provided between the battery module and the plate; and a blocking part provided between the battery module and the plate and blocking the heat sink from flowing into the drain hole.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0175164, filed December 8, 2021, and Korean Patent Application No. 10-2022-0165722, filed December 1, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery pack capable of preventing clogging of drain holes formed in a battery module, and a method for manufacturing the same. [Background technology]

[0003] Generally, a secondary battery is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in the field of advanced electronic devices such as phones, laptops, and camcorders.

[0004] The secondary battery can be classified into various types depending on the structure of the electrode assembly, for example, a stack type structure, a wound type (jelly roll type) structure, and a stack / folding type structure.

[0005] The secondary battery includes an electrode assembly and a pouch that accommodates the electrode assembly. The electrode assembly has a structure in which electrodes and separators are alternately stacked.

[0006] Meanwhile, secondary batteries are used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by an electrical drive source.

[0007] That is, the automobile uses a battery pack in which multiple secondary batteries are connected in series or parallel, and the battery pack includes a battery module made up of multiple secondary batteries, a plate on which the battery module is placed, and a heat sink provided between the battery module and the plate.

[0008] Here, a drain hole is formed on the bottom surface of the battery module to allow the electrolyte and moisture generated inside the battery module to be discharged to the outside.

[0009] However, in conventional battery packs, when a battery module is placed on a plate, the heat sink flows into a drain hole formed in the battery module, causing the drain hole to become clogged. As a result, there is a problem in that the electrolyte and moisture generated inside the battery module cannot be discharged through the drain hole. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to provide a battery pack and a manufacturing method thereof that includes a blocking portion to prevent the drain hole formed in the battery module from being clogged by a heat sink, thereby enabling the electrolyte and moisture generated inside the battery module to be stably discharged through the drain hole. [Means for solving the problem]

[0011] To solve the above problems, the battery pack of the present invention may include a battery module having a drain hole formed on a bottom surface thereof; a plate having the battery module disposed on an upper surface thereof; a heat sink provided between the battery module and the plate; and a blocking part provided between the battery module and the plate and blocking the heat sink from flowing into the drain hole.

[0012] The battery module may include a secondary battery, a module case in which the secondary battery is housed, and a module cover coupled to both opposing side surfaces of the module case in a lengthwise direction and electrically connected to the secondary battery, wherein the drain hole is formed at one end of a bottom surface of the module case to which the module cover is coupled, and the blocking part may be provided in a form that covers the remaining portion of the drain hole excluding a portion facing the module cover.

[0013] The interrupter may be integrally provided on the bottom surface of the module case.

[0014] The blocking portion may be coupled to a bottom surface of the module case.

[0015] The blocking portion may be bonded to the bottom surface of the module case via an adhesive.

[0016] The blocking portion may be coupled to an insertion groove formed on a bottom surface of the module case.

[0017] The blocking portion may be made of a material having a restoring force.

[0018] The blocking portion may be made of a material capable of absorbing moisture.

[0019] The blocking portion may be made of polyurethane material.

[0020] The interrupting portion may be coated with an insulator having insulating properties.

[0021] The insulator may be coated only on the remaining surfaces of the blocking portion except for the surface facing the drain hole.

[0022] The insulator may be made of polyethylene.

[0023] Meanwhile, a method for manufacturing a battery pack according to the present invention may include a battery module manufacturing step of manufacturing a battery module having a drain hole formed on a bottom surface thereof; a blocking unit providing step of providing a blocking unit on the bottom surface of the battery module where the drain hole is located; a heat sink forming step of forming a heat sink by pouring a viscous heat sink material onto an upper surface of a plate; and a battery module assembling step of placing the battery module on the upper surface of the plate on which the heat sink is formed, whereby the heat sink expands between the battery module and the plate to fill an empty space between the battery module and the plate, and at this time, the heat sink expanding toward the drain hole is blocked from flowing into the drain hole by the blocking unit.

[0024] The manufacturing of the battery module may include preparing a secondary battery, coupling module covers to both opposing sides of a module case in a length direction, and housing the secondary battery in the module case and then electrically connecting the secondary battery to the module cover to manufacture a battery module. The drain hole may be formed at one end of a bottom surface of the module case to which the module cover is coupled. In the providing of the interrupter, the interrupter may be provided on the bottom surface of the module case, and may be provided in a form that covers the remaining portion of the drain hole excluding a portion of the drain hole facing the module cover.

[0025] In the providing step, the interrupting part is made of a material having a resilience, and in the connecting step, when the battery module is connected to the upper surface of the plate on which the heat sink is formed, the interrupting part can be compressed by the connecting force between the battery module and the plate.

[0026] In the step of providing the blocking portion, the blocking portion may be made of a material capable of absorbing moisture.

[0027] The step of providing the blocking portion may further include coating an insulator having insulating properties on the remaining surface of the blocking portion except for the surface of the blocking portion facing the drain hole. [Effects of the Invention]

[0028] The battery pack of the present invention includes a blocking portion, which can block the heat sink from flowing into the drain hole formed in the battery module, thereby allowing the electrolyte and moisture generated inside the battery module to be stably discharged. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a perspective view showing a battery pack according to a first embodiment of the present invention. [Figure 2] 1 is an exploded perspective view showing a battery pack according to a first embodiment of the present invention. [Figure 3] 1 is a cross-sectional perspective view showing a battery module of a battery pack according to a first embodiment of the present invention. [Figure 4] 2 is a bottom perspective view showing the interrupter of the battery pack according to the first embodiment of the present invention. FIG. [Figure 5] FIG. 5 is a bottom view of FIG. 4. [Figure 6] 1 is a cross-sectional view showing a battery pack according to a first embodiment of the present invention. [Figure 7] FIG. 2 is a bottom perspective view showing a blocking portion coated with an insulator in the first embodiment of the present application. [Figure 8] FIG. 8 is a cross-sectional view taken along line AA shown in FIG. 7. [Figure 9] 3 is a flowchart showing a battery pack manufacturing method according to the first embodiment of the present invention. [Figure 10] FIG. 10 is a bottom perspective view showing a battery pack according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. In the drawings, parts that are not relevant to the description will be omitted in order to clearly explain the present invention, and similar parts will be designated by similar reference numerals throughout the specification.

[0031] [Battery pack according to the first embodiment of the present invention] The battery pack according to the first embodiment of the present invention has a structure that prevents the drain holes formed in the battery module from being clogged by a heat sink, thereby allowing the electrolyte and moisture generated inside the battery module to be stably discharged through the drain holes.

[0032] FIG. 1 is a front perspective view of a battery pack according to a first embodiment of the present invention, FIG. 2 is a bottom perspective view of the battery pack according to the first embodiment of the present invention, and FIG. 3 is a partial cross-sectional perspective view of the battery pack according to the first embodiment of the present invention.

[0033] As an example, as shown in Figures 1 to 3, a battery pack 100 according to a first embodiment of the present invention includes a battery module 110 having a drain hole formed therein, a plate 120 on which the battery module 110 is disposed, a heat sink 130 provided between the battery module 110 and the plate 120, and a blocking portion 140 that blocks the heat sink 130 from flowing into the drain hole 112a formed in the battery module 110.

[0034] Battery module The battery module 110 has a structure in which at least one secondary battery 111 is housed and a drain hole 112a is formed in the bottom surface (the bottom surface of the battery module as viewed in FIG. 2).

[0035] That is, referring to FIG. 3, the battery module 110 includes at least one secondary battery 111, a module case 112 having a structure that opens in the front-to-back direction (the left-to-right direction of the battery module when viewed in FIG. 1) and that houses the secondary battery 111, and a module cover 113 that is coupled to the front and rear sides (the left and right sides of the module case when viewed in FIG. 1) of the module case 112, respectively, and is provided with bus bars 113a that are electrically connected to the secondary battery 111.

[0036] The secondary battery 111 has a structure in which a plurality of electrodes are alternately stacked with a separator interposed therebetween, and the plurality of electrodes may be positive and negative electrodes. The positive electrode is connected to a positive electrode tab and a positive electrode lead, and the negative electrode is connected to a negative electrode tab and a negative electrode lead.

[0037] Meanwhile, the secondary battery 111 has a structure in which at least one, preferably two or more, positive and negative electrode leads are arranged vertically in the front-rear direction of the module case 112 .

[0038] The module case 112 has the form of a box that is open in the front-to-rear direction (the left-to-right direction when viewed in FIG. 1), and houses at least one or more secondary batteries 111 inside. A drain hole 112a is formed at one end of the bottom surface of the module case 112 to which the module cover 113 is coupled (the lower left end of the module case in FIG. 2).

[0039] Here, the drain hole 112a serves as a passage for discharging the electrolyte or moisture generated inside the module case 112. In particular, the drain hole is formed at one end of the bottom surface of the module case to quickly discharge the moisture.

[0040] The module cover 113 is coupled to the front and rear surfaces of the module case 112 to seal the front and rear surfaces of the module case 112, and includes a bus bar 113a electrically connected to the secondary battery 111.

[0041] plate The plate 120 is a component for mounting the battery module 110. That is, the plate 120 is made of a rectangular metal plate, and the battery module 110 is mounted on the top surface. At this time, the battery module may be attached to the plate so that it does not move. That is, the plate 120 and the battery module 110 may be attached via bolts.

[0042] heat sink The heat sink 130 is provided between the battery module 110 and the plate 120 and transfers heat generated in the battery module to the plate. That is, the heat sink 130 is made of a material for dissipating heat from the battery module 110 arranged on the plate 120. In summary, the heat sink 130 is provided between the battery module 110 and the plate 120 and transfers heat generated in the battery module 110 to the plate, which then releases the transferred heat to the outside. This prevents the temperature of the battery module 110 from rising.

[0043] Here, the heat sink 130 has a property of being stretched by a pressure force. That is, when the battery module 110 is coupled to the upper surface of the plate 120, the heat sink 130 is stretched or expanded by the coupling force between the battery module 110 and the plate 120, thereby filling the empty space between the battery module 110 and the plate 120.

[0044] Meanwhile, the heat sink 130 may be formed by pouring a viscous heat sink material onto the plate 120 and then solidifying it.

[0045] For example, the heat sink 130 may be made of any one of carbon nanofiber, alumina, and graphite.

[0046] However, when the battery module and the plate are joined, the heat sink flows into the drain hole formed in the battery module, causing the drain hole to become clogged. To prevent this, the battery pack 100 according to the first embodiment of the present invention includes a blocking portion that blocks the heat sink from flowing into the drain hole.

[0047] The interrupter will be described in more detail below.

[0048] Breaker The blocking portion 140 is provided between the battery module and the plate and has a structure for blocking the heat sink 130 from flowing into the drain hole 112a.

[0049] That is, the blocking part 140 is provided on the bottom surface of the module case 112, and is provided in a form that encloses the remaining part of the drain hole 112a excluding a portion (the left side of the drain hole as viewed in FIG. 2) of the drain hole 112a facing the module cover 113. As a result, the blocking part 140 can prevent the heat sink 130 from flowing into the drain hole 112a when the battery module 110 and the plate 120 are combined, thereby preventing the drain hole 112a from being clogged with the heat sink 130.

[0050] FIG. 4 is a bottom perspective view showing a cutoff portion of a battery pack according to a first embodiment of the present invention, FIG. 5 is a bottom view of FIG. 4, and FIG. 6 is a cross-sectional view showing a battery pack according to the first embodiment of the present invention.

[0051] 4 to 6, the drain hole has a rectangular shape, and the blocking part 140 is provided in a V shape to surround three sides of the drain hole 112a except for one side (the left side of the drain hole as viewed in FIG. 2) facing the module cover 113. As a result, the blocking part 140 can block the heat sink 130 from flowing into the remaining three sides of the drain hole 112a, thereby preventing the heat sink 130 from flowing into the drain hole 112a.

[0052] Meanwhile, in this embodiment, the blocking portion 140 in a "Y" shape has been described as one embodiment, but it can be applied to various shapes such as a circle, an oval, an L-shape, a U-shape, and the like.

[0053] Meanwhile, the blocking part 140 may be made of a material having compressive and restoring forces in order to minimize the space between the battery module 110 and the plate 120. In particular, the blocking part 140 may be formed to have the same thickness as the heat sink 130 when compressed. This can prevent unnecessary space from being generated between the battery module 110 and the plate 120 due to the blocking part 140.

[0054] In addition, the blocking part 140 may be made of a material that absorbs the electrolyte and moisture discharged into the drain hole 112a, thereby preventing contamination caused by the electrolyte or moisture discharged into the drain hole 112a.

[0055] For example, the blocking portion 140 may be made of polyurethane, which has excellent heat resistance, abrasion resistance, solvent resistance, and chemical resistance, and is also used as a heat insulating material and a sound absorbing material.

[0056] 2, the blocking unit 140 may be integrally formed on the bottom surface of the module case. That is, the blocking unit 140 may be manufactured at the same time as the module case is manufactured. This can improve the connection between the module case and the blocking unit and increase ease of manufacturing.

[0057] 4, in another embodiment, the blocking unit 140 may be manufactured separately from the module case and then coupled to the bottom surface of the module case, thereby allowing the blocking unit 140 to be replaced depending on whether it is damaged or contaminated.

[0058] Meanwhile, the blocking unit 140 may be attached to the bottom surface of the battery module 110 using an adhesive, thereby allowing the blocking unit 140 to be easily attached to the module case and increasing the flow phenomenon and fixing strength.

[0059] FIG. 7 is a bottom perspective view showing an insulating-coated interrupter in the first embodiment of the present application, and FIG. 8 is a cross-sectional view taken along line AA shown in FIG.

[0060] Meanwhile, referring to FIGS. 7 and 8, the outer circumferential surface of the blocking portion 140 may be coated with an insulator 150 having insulating properties for insulating between the battery module 110 and the plate 120 .

[0061] In particular, the insulator 150 may be made of an elastic material and may be coated on the remaining surfaces of the blocking portion 140 except for the surface facing the drain hole 112a. As a result, the blocking portion 140 can absorb the electrolyte or moisture discharged from the drain hole 112a through the surface not coated with the insulator 150, thereby improving the insulation between the battery module 110 and the plate 120 via the insulator 150.

[0062] On the other hand, the insulator 150 may be made of polyethylene, which is a plastic that is harmless to the human body and is widely used as an electrical insulator for household items, toys, and the like.

[0063] Therefore, the battery pack 100 according to the first embodiment of the present invention includes the blocking portion 140, thereby preventing the heat sink 130 from flowing into the drain hole 112a formed in the battery module 110, thereby allowing the electrolyte and moisture generated inside the battery module 110 to be discharged to the drain hole 112a.

[0064] A method for manufacturing the battery pack 100 according to the first embodiment of the present invention will now be described.

[0065] FIG. 9 is a flowchart showing a method for manufacturing a battery according to the first embodiment of the present invention.

[0066] [Method of manufacturing a battery according to the first embodiment of the present invention] As shown in FIG. 9, the method for manufacturing a battery according to the first embodiment of the present invention includes the steps of manufacturing a battery module, providing a cutoff part, forming a heat sink, and assembling the battery modules.

[0067] Battery module manufacturing stage In the battery module manufacturing step, a battery module 110 is manufactured, in which at least one secondary battery 111 is housed and in which a drain hole 112a is formed in the bottom surface.

[0068] Meanwhile, the battery module 110 includes at least one secondary battery 111, a module case 112 that has a structure that opens in the front-to-rear direction (left-to-right direction when viewed in FIG. 1) and accommodates the secondary battery 111, and a module cover 113 that is coupled to the front and rear sides (left and right sides of the module case when viewed in FIG. 1) of the module case 112, respectively, and is electrically connected to the secondary battery 111. Here, a drain hole 112a is formed at one end of the bottom of the module case 112 to which the module cover 113 is coupled (the lower left end of the module case in FIG. 2), and the drain hole 112a serves as a passage for discharging electrolyte and moisture generated inside the module case 112 to the outside.

[0069] That is, the battery module manufacturing step includes a process of preparing a secondary battery 111, a process of attaching a module cover 113 to both opposing sides of the module case 112 in the overall length direction, and a process of housing the secondary battery 111 in the module case 112 and then electrically connecting it to the module cover 113 to manufacture a battery module 110.

[0070] Breaker part installation stage The blocking portion providing step includes providing a blocking portion 140 having a first thickness on a bottom surface of the battery module 110 located outside the drain hole 112a. In particular, the blocking portion 140 may be integrally provided on the bottom surface of the battery module 110 or attached using an adhesive.

[0071] For example, the drain hole 112a has a rectangular shape, and the blocking part 140 is provided in a square shape to surround three sides of the drain hole 112a except for one side facing the module cover 113. As a result, in the step of assembling the battery module, the blocking part 140 can effectively block the heat sink 130 from flowing into the remaining three sides of the drain hole 112a, thereby preventing the heat sink 130 from flowing into the drain hole 112a.

[0072] Meanwhile, the blocking portion 140 may be made of a material having compressive and restoring force and capable of absorbing moisture, i.e., polyurethane.

[0073] Meanwhile, the step of providing the blocking portion may further include an insulator coating process to enhance the insulating properties of the blocking portion 140 facing the drain hole 112a. That is, the step of providing the blocking portion may coat only the remaining surfaces of the blocking portion 140 except for the surface facing the drain hole 112a with an insulator having insulating properties.

[0074] Heat sink formation stage In the heat sink forming step, a viscous heat sink material is poured onto the upper surface of the plate 120 to form the heat sink 130 .

[0075] Meanwhile, the heat sink 130 may be made of polyethylene.

[0076] Battery module assembly stage In the battery module coupling step, the battery module 110 is coupled to the upper surface of the plate 120 on which the heat sink 130 is formed. Then, the heat sink 130 expands between the battery module 110 and the plate 120 due to the coupling force between the battery module 110 and the plate 120, thereby filling the empty space between the battery module 110 and the plate 120. At this time, the heat sink 130 expanding toward the drain hole 112a is blocked by the blocking portion 140, thereby preventing the heat sink 130 from flowing into the drain hole 112a.

[0077] Meanwhile, in the battery module combining step, when the battery module 110 and the plate 120 are combined, the blocking portion 140 is compressed to a second thickness that is smaller than the first thickness, thereby preventing a large gap between the battery module 110 and the plate 120.

[0078] On the other hand, the second thickness may be the same as the thickness of the extended heat sink 130 .

[0079] Once the above steps are completed, the battery pack is manufactured.

[0080] In the following description of other embodiments of the present invention, the same reference numerals will be used for components having the same configuration as those in the above-described embodiment, and duplicated descriptions will be omitted.

[0081] [Battery pack according to a second embodiment of the present invention] FIG. 10 is a bottom perspective view showing a battery pack according to a second embodiment of the present invention.

[0082] As shown in FIG. 10, the battery pack 100 according to the second embodiment of the present invention includes a blocking portion 140 provided on the bottom surface of the battery module 110 to block the heat sink 130 from flowing into the drain hole 112a.

[0083] Here, the bottom surface of the battery module 110 may be formed with an insertion groove 112b into which the blocking part 140 is inserted.

[0084] That is, an insertion groove 112b is formed on the bottom surface of the battery module 110, and a part of the blocking part 140 (the upper part of the blocking part as viewed in FIG. 10) is inserted into the insertion groove 112b. This makes it possible to easily check the coupling position of the blocking part 140 and prevent the blocking part 140 from moving. Meanwhile, the insertion groove 112b may have the same shape as the outer shape of the blocking part 140.

[0085] The scope of the present invention is defined by the claims that follow rather than by the above detailed description, and various embodiments are possible that are derived from the meaning and scope of the claims and their equivalents. [Explanation of symbols]

[0086] 100 battery packs 110 Battery Module 111 Secondary battery 112 Module Case 112a Drain Hole 112b Insertion groove 113 Module Cover 113a busbar 120 plates 130 Heat sink 140 Breaker 150 Insulator

Claims

1. a battery module having a drain hole formed on the bottom surface; a plate on which the battery module is disposed; a heat sink made of polyethylene and provided between the battery module and the plate so as to fill the empty space between the battery module and the plate; and The battery pack further comprises a blocking portion disposed between the battery module and the plate, the blocking portion blocking the heat sink from flowing into the drain hole.

2. the battery module includes a secondary battery, a module case in which the secondary battery is accommodated, and module covers coupled to both sides of the module case facing each other in a length direction and electrically connected to the secondary battery, the drain hole is formed at one end of a bottom surface of the module case to which the module cover is coupled; The battery pack of claim 1 , wherein the blocking portion is provided in a form that encloses the remaining portion of the drain hole except for a portion of the drain hole that faces the module cover.

3. The battery pack according to claim 2 , wherein the cutoff portion is integrally provided on a bottom surface of the module case.

4. The battery pack according to claim 2 , wherein the cutoff portion is coupled to a bottom surface of the module case.

5. The battery pack according to claim 4 , wherein the interrupter is attached to the bottom surface of the module case via an adhesive.

6. The battery pack according to claim 4 , wherein the cutoff portion is coupled to an insertion groove formed on a bottom surface of the module case.

7. The battery pack according to claim 1 , wherein the interrupting portion is made of a material having a restoring force.

8. The battery pack according to claim 1 , wherein the interrupting portion is made of a material capable of absorbing moisture.

9. The battery pack according to claim 1 , wherein the blocking portion is made of polyurethane material.

10. The battery pack according to claim 1 , wherein the interrupter is coated with an insulating material.

11. The battery pack according to claim 10 , wherein the insulator is coated only on the remaining surface of the blocking portion excluding the surface of the blocking portion facing the drain hole.

12. 12. The battery pack of claim 11, wherein the insulator is formed from polyethylene.

13. a battery module manufacturing step of manufacturing a battery module having a drain hole formed on a bottom surface thereof; a step of providing a cutoff part on a bottom surface of the battery module where the drain hole is located; forming a heat sink by pouring a heat sink material onto the top surface of the plate, the heat sink material being polyethylene; and and a connecting step of connecting the battery module and the plate, the connecting step being performed in such a manner that the heat sink expands between the battery module and the plate to fill a space between the battery module and the plate when the battery module is disposed on an upper surface of the plate on which the heat sink is formed, and the heat sink expanding toward the drain hole is blocked from flowing into the drain hole by a blocking portion.

14. the manufacturing step of the battery module includes a step of preparing a secondary battery; a step of attaching module covers to both sides of a module case that face each other in a length direction; and a step of housing the secondary battery in the module case and then electrically connecting the secondary battery to the module cover to manufacture a battery module; the drain hole is formed at one end of a bottom surface of the module case to which the module cover is coupled; 14. The method of claim 13, wherein in the providing step, the blocking part is provided on the bottom surface of the module case, and is provided in a form that encloses the remaining part except for a part of the drain hole leading to the module cover.

15. In the step of providing the interrupting portion, the interrupting portion is formed from a material having a restoring force, 14. The method of claim 13, wherein, in the battery module coupling step, when the battery module is coupled to an upper surface of the plate on which the heat sink is formed, the blocking portion is compressed by a coupling force between the battery module and the plate.

16. The method of manufacturing a battery pack according to claim 14 , wherein in the providing step, the interrupting portion is made of a material capable of absorbing moisture.

17. 15. The method of claim 14, wherein the providing step further comprises coating an insulating material on the remaining surface of the blocking portion except for the surface of the blocking portion facing the drain hole.

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