Battery pack

Abstract

The content disclosed herein relates to a battery pack, in one example, the battery pack includes: a battery pack case provided with a bottom plate; and a plurality of battery cell units mounted on the top of the bottom plate, in which a thermal resin and a TIM pad are interposed in parallel between the bottom surface of the battery cell unit and the bottom plate to fix the battery cell unit, and the adhesive force of the TIM pad is smaller than the adhesive force of the thermal resin.

Description

Technical Field

[0001] The present disclosure relates to a battery pack, and more particularly, to a battery pack capable of replacing a portion of a plurality of battery cells installed in the battery pack when a problem occurs, thereby extending the service life of the battery pack with minimal maintenance without discarding the entire battery pack.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0072978, filed on Jun. 7, 2023, the disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] In order to improve the space utilization of the battery pack, a cell-to-pack structure has been proposed. The cell-to-pack structure has the advantage of improving the space utilization of the battery pack by directly assembling a plurality of battery cells into the battery pack without modularization.

[0004] Since the module-free structure omits or simplifies the separate module housing, a new structure is proposed to effectively install multiple battery cells into the battery pack housing. For example, a battery cell unit (equivalent to a conventional battery module) formed by a group of multiple battery cells can be combined with a side frame, thereby designing a structure that replaces the role of a conventional battery pack cross beam (referring to a cross beam integrated with the battery pack housing) by ensuring that the side frames of adjacent battery cells are joined together and has sufficient rigidity.

[0005] In addition, since a separate module housing is not required, thermal resin can be interposed between the bottom surface of the battery cell unit (on which the battery cell is exposed) and the bottom plate of the battery pack to promote conductive heat dissipation of the battery cell unit, and the battery cell unit can be further firmly fixed by curing the thermal resin.

[0006] However, for a module-free structure, a battery pack structure in which the battery cell unit is further fixed by curing of a thermal resin has many advantages, such as improving the space utilization of the battery pack by directly assembling multiple battery cells into the battery pack without a modular structure, and improving the heat dissipation performance by heat conduction compared to a structure with an additional layer of a module housing, but it has disadvantages in terms of maintenance of the battery pack. In other words, such a module-free structure makes it very difficult to disassemble the battery pack into the battery cell unit once assembled. For example, when removing the battery cell unit, the cured thermal resin used to fix the bottom surface of the battery cell unit may cause the battery cell bonded to the thermal resin to rupture, which may lead to quite dangerous consequences such as electrolyte leakage.

[0007] It is highly desirable to develop a battery pack having a module-free structure that can be easily disassembled into battery cell units so that even if only one battery cell in the battery pack fails, the battery pack can be maintained by replacing the battery cell unit, thereby allowing the battery pack to be used within its designed service life without the need to discard the expensive battery pack. Summary of the invention

[0008] Technical issues

[0009] The present disclosure is directed to providing a battery pack having a module-free structure, in which any battery cell unit can be easily removed regardless of the assembly order, thereby facilitating replacement of a faulty battery cell.

[0010] However, the technical problems that the present disclosure attempts to solve are not limited to the above problems, and a person skilled in the art can clearly understand other problems not mentioned from the description of the present disclosure set forth below.

[0011] Technical Solution

[0012] The present disclosure relates to a battery pack. In one example, the battery pack includes: a battery pack case provided with a bottom plate; and a plurality of battery single cells mounted on top of the bottom plate, wherein a thermal resin and a TIM pad are inserted in parallel between a bottom surface of the battery single cell and the bottom plate to fix the battery single cell, and the adhesive force of the TIM pad is smaller than that of the thermal resin.

[0013] Thermal resin may be applied along the perimeter of the TIM pad.

[0014] The bonding strength of the battery cell unit to the bottom plate is adjusted by the area ratio between the bonding area of ​​the thermal resin and the bonding area of ​​the TIM pad.

[0015] The thermal resin may form a curable adhesive layer, and the TIM pad may form a non-curable adhesive layer.

[0016] In an exemplary embodiment, the bonding area of ​​the TIM pad may occupy 60% to 90% of the total area of ​​the bottom surface of the battery cell unit.

[0017] A pair of TIM pads are provided, which are spaced apart from each other and may be disposed on a bottom surface of the battery cell unit.

[0018] In this case, the thermal resins coated along the respective peripheries of the paired TIM pads may be isolated from each other.

[0019] At the same time, in the battery pack of the present invention, the battery pack housing includes a cross beam, which is combined with the bottom plate to laterally divide the accommodating space in the bottom plate, and the battery single unit is provided with a side frame, which is fixed to the cross beam, wherein the side frames of the battery single units adjacent in the longitudinal direction share the upper surface of the cross beam located therebetween and may not overlap with each other in the vertical direction.

[0020] The side frame includes a side plate surrounding a side of the battery cell unit and a support block protruding from the side plate, wherein the support blocks of the battery cell units adjacent in the longitudinal direction may occupy areas of the upper surface of the cross beam that do not overlap each other.

[0021] For example, the side frame is provided with a plurality of support blocks spaced apart from each other, wherein the plurality of support blocks of the battery single units adjacent in the longitudinal direction may be alternately arranged on the upper surface of the cross beam.

[0022] In addition, the battery cell units may be fixed to the cross beams by bolts that vertically penetrate the support blocks.

[0023] Beneficial Effects

[0024] In the battery pack of the present disclosure having the above-mentioned configuration, the adhesive force for fixing the battery cell unit to the base plate is provided by both the thermal resin and the TIM pad, and by limiting the bonding area of ​​the curable thermal resin so that it is only partially bonded to the bottom surface of the battery cell unit, it is easier to remove the faulty battery cell unit from the battery pack, thereby allowing the entire battery pack to be maintained, repaired and reused without discarding the entire battery pack.

[0025] In particular, the battery pack of the present disclosure can be adapted to a module-free structure, wherein the heat dissipation of the bottom surface of the battery cell unit is sufficiently improved by both the thermal resin and the TIM pad, and the bonding area of ​​the non-curable TIM pad having relatively low bonding force can be adjusted so as to design the fixing strength to a level that is both strong and enables future separation of the battery cell unit.

[0026] Furthermore, by designing the side frames of the individual battery cells to share the upper surface of a single cross beam without stacking one another, if only one battery cell in the assembled battery pack has a problem, the faulty battery cell can be easily removed regardless of the assembly order.

[0027] However, the technical effects of the present disclosure are not limited to the above-mentioned effects, and a person skilled in the art may clearly understand other effects not mentioned from the description of the present disclosure set forth below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings attached to this specification illustrate exemplary embodiments of the present disclosure and are used to facilitate understanding of the technical idea of ​​the present disclosure together with the following detailed description of the present disclosure, and thus the present disclosure should not be restrictively interpreted based on the drawings.

[0029] Figure 1 is a diagram illustrating a fixing structure of a battery cell unit in a battery pack according to the present disclosure.

[0030] Figure 2 It is along Figure 1 Cross-sectional view of the “AA” line cut.

[0031] Figure 3 is shown removed from the battery pack Figure 2 An example diagram of a battery cell in FIG.

[0032] Figure 4 is a diagram showing an exemplary mounting structure of a thermal resin and a TIM pad.

[0033] Figure 5 is a diagram illustrating a mounting structure of a battery cell unit according to one embodiment of the present disclosure.

[0034] Figure 6 is based on Figure 5 A plan view of a battery pack of an embodiment. DETAILED DESCRIPTION

[0035] The present disclosure may have various modifications and various embodiments, so specific embodiments thereof will be described in detail below.

[0036] However, it should be understood that the present disclosure is not limited to the specific embodiments, and includes all modifications, equivalents, or substitutes within the spirit and technical scope of the present disclosure.

[0037] The terms "include", "comprising" and "having" as used herein indicate the presence of features, numbers, steps, actions, parts or components or a combination thereof described in the specification. It should be understood that the presence or possibility of adding one or more other features, numbers, steps, actions, parts, components or a combination thereof are not excluded in advance.

[0038] Furthermore, in the present disclosure, when a portion of a layer, film, region, plate, etc. is disposed “on” another portion, this includes not only a case where one portion is “directly” disposed “on” another portion, but also a case where another portion is interposed between the portion and the other portion. In contrast, when a portion of a layer, film, region, plate, etc. is disposed “below” another portion, this includes not only a case where one portion is “directly” disposed “below” another portion, but also a case where another portion is interposed between the portion and the other portion. Furthermore, in the present application, “on…” may include not only a case where it is disposed on an upper portion, but also a case where it is disposed on a lower portion.

[0039] The present disclosure relates to a battery pack, in one example, the battery pack includes: a battery pack case, the battery pack case is provided with a bottom plate; and a plurality of battery single cells, the plurality of battery single cells are mounted on top of the bottom plate, wherein a thermal resin and a TIM pad are inserted in parallel between a bottom surface of the battery single cell and the bottom plate to fix the battery single cell, and the adhesive force of the TIM pad is smaller than that of the thermal resin.

[0040] In the battery pack of the present disclosure having such a configuration, the adhesive force for fixing the battery cell unit to the base plate is provided by both the thermal resin and the TIM pad, and by limiting the bonding area of ​​the curable thermal resin so that it only partially adheres to the bottom surface of the battery cell unit, a faulty battery cell unit can be more easily removed from the battery pack, thereby enabling it to be maintained, repaired and reused without discarding the entire battery pack.

[0041] [Embodiments of the present disclosure]

[0042] Hereinafter, with reference to the accompanying drawings, a specific embodiment of the battery pack 10 according to the present disclosure will be described in detail. As a reference, the front-rear, vertical and left-right directions used to designate relative positions in the following description are intended to help understand the present disclosure, and unless otherwise defined, these directions refer to the directions shown in the accompanying drawings.

[0043] [First embodiment]

[0044] Figure 1 is a diagram showing a fixing structure of a battery cell unit 200 in a battery pack 10 according to the present disclosure, Figure 2 It is along Figure 1 Cross-sectional view of the “AA” line cut.

[0045] The present disclosure relates to a battery pack 10, which includes a battery pack housing 100 and a plurality of battery cell units 200 installed in the battery pack housing 100. As used herein, the battery cell unit 200 refers to a plurality of battery cells 210 fixed together as a group and includes a structure for making the plurality of battery cells 210 into a unit. For example, the battery cell unit 200 may include a bus bar frame assembly 220 and a side frame 230, the bus bar frame assembly 220 mechanically and electrically combined with the plurality of battery cells 210 at the lateral ends where the leads (not shown) of the battery cells 210 protrude, and the side frame 230 protects the battery cells 210 on both longitudinal sides. And, in order to make the battery cell unit 200 shown suitable for the battery pack 10 of a non-module structure, the battery cells 210 are exposed on the bottom surface without any additional structure.

[0046] The battery pack housing 100 includes a bottom plate 110 as a bottom plate. The bottom plate 110 supports the bottom surface of the battery cell unit 200 and is used to absorb heat from the bottom surface of the battery cell unit 200 in the form of heat conduction and dissipate the heat to the outside. The bottom plate 110 itself may have a heat sink built therein, or a separate heat sink may be bonded to its bottom surface so that the absorbed heat can be dissipated to the outside via a coolant. The configuration of the heat sink itself is not critical to the present disclosure, so it will not be described or illustrated.

[0047] A plurality of battery cell units 200 mounted on the bottom plate 110 (as one of the fixing structures for the battery pack housing 100) may have a thermal resin 300 having excellent thermal conductivity applied to the bottom surface of the battery cell unit 200. The thermal resin 300 has the characteristics of a viscous gel when applied, but hardens into a solid after being exposed to air for a period of time. As a result of this curing of the thermal resin 300, the bottom surface of the battery cell unit 200 is firmly fixed to the bottom plate 110.

[0048] However, such curing of the thermal resin 300 can firmly fix the battery cell unit 200 in place, but if the battery cell unit 200 fails, it will hinder the removal of the battery cell unit 200 from the battery pack 10. In many cases, it is almost impossible to remove the battery cell unit 200 adhered with the thermal resin 300, or even if it is removed, it may cause damage to the battery cell unit 200 itself, other battery cell units 200 nearby, and even the battery pack case 100. Because of this, the irreparable battery pack 10 has to be discarded in its entirety.

[0049] The battery pack 10 of the present disclosure is intended to solve these problems and is characterized in that a thermal resin 300 and a TIM pad 400 are inserted in parallel between the bottom surface of the battery cell unit 200 and the bottom plate 110 to fix the battery cell unit 200, wherein the adhesive force of the TIM pad 400 is smaller than the adhesive force of the thermal resin 300.

[0050] Inserting the thermal resin 300 and the TIM pad 400 in parallel means that the bonding surface between the bottom surface of the battery cell unit 200 and the upper surface of the bottom plate 110 is partially composed of the thermal resin 300 and partially composed of the TIM pad 400, rather than the thermal resin 300 and the TIM pad 400 being stacked from top to bottom (inserted in series). Figure 1 and Figure 2 This can be clearly understood.

[0051] The TIM pad 400 refers to a slightly elastic pad on which a thermally conductive thermal interface material (TIM) is coated or embedded, and generally has adhesive layers on both sides (for example, double-sided tape is adhered to both sides thereof), and has the same function as the thermal resin 300, having high thermal conductivity and fast thermal conductivity. The TIM pad 400 has adhesive layers on both sides, and the adhesive layers are respectively adhered to the bottom surface of the battery cell unit 200 and the upper surface of the bottom plate 110, and the TIM pad 400 very weakly bonds the battery cell unit 200 to the bottom plate 110 compared to the thermal resin 300. Therefore, the TIM pad 400 alone is insufficient to fix the battery cell unit 200 to the bottom plate 110.

[0052] By combining the characteristics of the thermal resin 300 and the TIM pad 400, such as adhesive strength and curing performance, the present disclosure provides sufficient fixing strength to the battery cell unit 200 and improves removability during maintenance. That is, the thermal resin 300 forms a curable adhesive layer 310, and the TIM pad 400 forms a non-curable adhesive layer 410, and the adhesive strength of the battery cell unit 200 and the bottom plate 110 is adjusted by the area ratio between the adhesive area of ​​the thermal resin 300 and the adhesive area of ​​the TIM pad 400. For example, considering the respective adhesive strengths of the thermal resin 300 and the TIM pad 400, the adhesive area of ​​the TIM pad 400 can be designed to occupy 60% to 90% of the total area of ​​the bottom surface of the battery cell unit 200, so that the battery cell unit 200 can be disassembled without applying excessive force.

[0053] Figure 3 is removed from the battery pack 10 Figure 2 An example diagram of a battery cell unit 200 in FIG. Figure 2As shown, the battery cell unit 200 is fixed to the bottom plate 110 by the curable adhesive layer 310 of the thermal resin 300 and the non-curable adhesive layer 410 of the TIM pad 400. When an upward pulling force is applied, the adhesive force of the non-curable adhesive layer 410 of the TIM pad 400 can be overcome with a small force, so that the battery cell unit 200 can be removed without significant damage. It should be noted that Figure 3 The curable adhesive layer 310 of the thermal resin 300 is shown to remain on the battery cell unit 200 by way of illustration only, and is not intended to imply that the battery cell unit 200 can only be Figure 3 Separate in the form shown.

[0054] Figure 4 3 is an exemplary illustration of the mounting structure of the thermal resin 300 and the TIM pad 400. Figure 4 As shown in (a) of FIG. 1 , a single TIM pad 400 may be disposed in the center, and the thermal resin 300 may be applied along the periphery of the TIM pad 400. Alternatively, as shown in FIG. Figure 4 As shown in (b), a pair of TIM pads 400 may be spaced apart, and thermal resin 300 may be applied along respective peripheries of the TIM pads 400 .

[0055] Here, if Figure 4 As shown in (b), the thermal resin 300 applied along the respective peripheries of the paired TIM pads 400 can be disconnected from each other. This creates a gap without any adhesive layer in the central area of ​​the bottom surface of the battery cell unit 200. When the battery cell unit 200 is separated, the gap can serve as a separation starting point to promote the peeling of the curable adhesive layer 310 formed by the thermal resin 300. This can separate the battery cell unit 200 more stably.

[0056] [Second embodiment]

[0057] In some cases, the bonding strength of the battery cell unit 200 to the bottom plate 110 (which can be adjusted according to the area ratio between the bonding area of ​​the thermal resin 300 and the bonding area of ​​the TIM pad 400) may need to be more firmly fixed to the battery cell unit 200. For example, this may be the case when the battery pack 10 is used in an environment with frequent vibrations. To this end, a detachable fixing structure may be added to the battery cell unit 200.

[0058] Figure 5 2 is a diagram showing a mounting structure of a battery cell unit 200 according to an embodiment of the present disclosure, Figure 6 is based on Figure 5 1 is a plan view of a battery pack 10 of an embodiment.

[0059] Reference Figure 5 and Figure 6The battery pack housing 100 includes a bottom plate 110, a side plate 120 coupled along the periphery of the bottom plate 110 to form a receiving space therein, and a crossbeam 130 coupled to the bottom plate 110 and laterally partitioning the receiving space inside the bottom plate 110. According to an embodiment, the battery pack housing may further include an intermediate beam 140, which is used to longitudinally partition the receiving space inside the bottom plate 110. Therefore, the receiving space of the battery pack housing may be divided into a grid by the crossbeam 130 and the intermediate beam 140, such as Figure 5 and Figure 6 shown.

[0060] Each accommodation space separated by the cross beam 130 is installed with a battery cell unit 200, so that the battery pack 10 can accommodate multiple battery cell units 200 to meet its design capacity. The battery cell unit 200 includes a plurality of battery cells 210 and a bus bar frame assembly 220, and the bus bar frame assembly 220 is mechanically and electrically combined with the plurality of battery cells 210 at the lateral ends where the leads (not shown) of the battery cells 210 protrude. The battery cell unit 200 also includes a side frame 230 that protects the battery cells 210 at both longitudinal sides.

[0061] The side frames 230 of the battery cell units 200 adjacent in the longitudinal direction share the upper surface of the cross beam 130 located therebetween and do not overlap each other. For example, in the illustrated embodiment, the side frames 230 include side plates 232 surrounding the sides of the battery cell units 200 and support blocks 234 protruding from the side plates 232. In addition, the support blocks 234 of the battery cell units 200 adjacent in the longitudinal direction occupy areas of the upper surface of the cross beam 130 that do not overlap each other.

[0062] In the battery cell unit 200 having such a configuration, to describe the support block 234 in more detail, the support block 234 of the side frame 230 is a protruding member capable of further supporting and fixing the battery cell unit 200 relative to the cross beam 130 so that the battery cell unit 200 is supported by the support block 234 on the upper surface of the cross beam 130. In addition, the battery cell unit 200 is fixed to the cross beam 130 by a bolt 240 vertically penetrating the support block 234. The clamping force of the bolt 240 is applied to the battery cell unit 200 through the head of the larger diameter supported at the entrance of the through hole 236.

[0063] Figure 6 The structure of the entire battery cell unit 200 installed in the battery pack 10 is shown. The battery cell units 200 adjacent in the longitudinal direction with the cross beam 130 therebetween support and fix each other and share the cross beam 130. To this end, the support blocks 234 of the battery cell units 200 adjacent in the longitudinal direction are alternately arranged on the upper surface of the cross beam 130 to occupy areas that do not overlap each other.

[0064] like Figure 6 As shown in the plan view of FIG. 1 , the side frames 230 of the battery cell units 200 (with the cross beams 130 between the battery cell units 200), especially the support blocks 234, share the upper surface of the single cross beam 130 but are not stacked on each other. Therefore, when a problem occurs in any of the battery cell units 200 in the assembled battery pack 10, it is easy to remove only the faulty battery cell unit 200 upward without interference regardless of the assembly order.

[0065] Therefore, the battery pack 10 of the present disclosure can maintain the battery pack 10 by replacing the faulty battery cell units 200 , so that the battery pack 10 can be fully utilized within its designed service life without discarding the entire expensive battery pack 10 .

[0066] The present disclosure has been described in more detail above through the drawings and embodiments. However, since the configuration described in the drawings or embodiments described herein is only an embodiment of the present disclosure and does not represent the entire technical concept of the present disclosure, it should be understood that the present disclosure covers various equivalents, modifications and substitutes on the filing date of the present application.

[0067] [Explanation of Reference Numerals]

[0068] 10: Battery Pack

[0069] 100: Battery pack housing

[0070] 110: Base plate

[0071] 120: Side panels

[0072] 130: Beam

[0073] 140: Middle beam

[0074] 200: Battery monomer unit

[0075] 210: Battery Cell

[0076] 220: Busbar frame assembly

[0077] 230: Side frame

[0078] 232: Side panels

[0079] 234: Support block

[0080] 236: Through hole

[0081] 240: Bolt

[0082] 300: Thermal resin

[0083] 310: Curable adhesive layer

[0084] 400:TIM pad

[0085] 410: Non-curable adhesive layer

Claims

1. A battery pack comprising: A battery pack housing, wherein the battery pack housing is provided with a bottom plate; as well as a plurality of battery cells mounted on top of the bottom plate, Wherein, thermal resin and TIM pads are inserted in parallel between the bottom surface of the battery monomer unit and the bottom plate to fix the battery monomer unit, and Compared with the adhesive force of the thermal resin, the adhesive force of the TIM pad is small.

2. The battery pack according to claim 1, wherein: The thermal resin is applied along the periphery of the TIM pad.

3. The battery pack according to claim 1, wherein: The bonding strength of the battery cell unit and the bottom plate is adjusted by an area ratio between a bonding area of ​​the thermal resin and a bonding area of ​​the TIM pad.

4. The battery pack according to claim 3, wherein: The thermal resin forms a curable adhesive layer, and the TIM pad forms a non-curable adhesive layer.

5. The battery pack according to claim 3, wherein: The bonding area of ​​the TIM pad occupies 60% to 90% of a total area of ​​the bottom surface of the battery cell unit.

6. The battery pack according to claim 2, wherein: A pair of TIM pads are provided, which are spaced apart from each other and disposed on the bottom surface of the battery cell unit.

7. The battery pack according to claim 6, wherein: The thermal resins applied along respective peripheries of the pair of TIM pads are isolated from each other.

8. The battery pack according to claim 1, wherein: The battery pack housing includes a crossbeam combined with the bottom plate to laterally partition the accommodation space within the bottom plate, and the battery cell unit is provided with a side frame fixed to the crossbeam, and The side frames of the battery monomer units adjacent to each other in the longitudinal direction share an upper surface of a cross beam located between the adjacent battery monomer units and do not overlap each other in the vertical direction.

9. The battery pack according to claim 8, wherein: The side frame includes a side plate surrounding a side of the battery cell unit and a support block protruding from the side plate, The support blocks of the battery single units adjacent to each other in the longitudinal direction occupy areas of the upper surface of the cross beam that do not overlap with each other.

10. The battery pack according to claim 9, wherein: The side frame is provided with a plurality of support blocks spaced apart from each other, Wherein, a plurality of support blocks of battery monomer units adjacent to each other in the longitudinal direction are alternately arranged on the upper surface of the crossbeam.

11. The battery pack according to claim 9, wherein: The battery cell unit is fixed to the cross beam by bolts vertically penetrating the support block.

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