Battery pack and device including same

Abstract

A battery pack according to an embodiment of the present invention includes: a battery assembly including a plurality of battery cells; a pack frame, one side of which is open and in which the battery assembly is mounted; a pack cover configured to cover one open side of the pack frame; and an adhesive configured to couple the battery assembly to at least one of the pack frame and the pack cover, wherein an adhesive strength of the adhesive is reduced at a high temperature of 130 ℃ or higher.

Description

Battery pack and device including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0198175 filed on December 27, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to a battery pack and a device including the same, and more specifically, to a battery pack capable of partial replacement and rework of internal components and a device including the same.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0006] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0007] Currently, secondary batteries can be classified according to the shape of the case into cylindrical batteries in which the electrode assembly is embedded in a cylindrical case, prismatic batteries in which the electrode assembly is embedded in a prismatic case, and pouch-type batteries in which the electrode assembly is embedded in a pouch-type case made of aluminum laminate sheet.

[0008] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module or battery pack in which multiple battery cells are electrically connected is used.

[0009] These battery modules improve capacity and output by connecting multiple battery cells in series or parallel to form a battery cell stack. Additionally, one or more battery modules can be mounted together with various control and protection systems, such as a Battery Disconnect Unit (BDU), Battery Management System (BMS), and cooling system, to form a battery pack.

[0010] Conventionally, to secure battery assemblies, such as battery modules or cells, within a battery pack, mechanical components were provided to physically fix the assemblies, or adhesives such as PU foam were used. However, incorporating mechanical components into the battery pack presents a problem in that energy density may decrease due to the space occupied by these components. Additionally, using adhesives such as PU foam presents the issue that the entire battery pack must be replaced even if only a few battery assemblies fail. Therefore, research is needed on a method to secure battery assemblies within a battery pack while resolving the aforementioned problems.

[0011] The problem that the present invention aims to solve is to fix the components within a battery pack so that they do not separate or detach from the battery pack, and specifically, to provide a battery pack and a device including the same in which the internal components can be partially replaced by using an adhesive whose adhesive strength decreases at high temperatures without the introduction of mechanical components.

[0012] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0013] A battery pack according to one embodiment of the present invention comprises: a battery assembly including a plurality of battery cells; a pack frame having one side open and on which the battery assembly is mounted; a pack cover covering the open side of the pack frame; and an adhesive that joins at least one of the battery assembly and the pack frame and the battery assembly and the pack cover; wherein the adhesive has reduced adhesive strength at a high temperature of 130°C or higher.

[0014] In one embodiment, the adhesive may comprise a thermoplastic resin.

[0015] In one embodiment, the adhesive comprises an expandable material that expands in volume at high temperatures, and the expandable material may comprise at least one of a hydrated alkali metal silicate, a polyhydric alcohol, a carbohydrate, a melamine compound, a urea compound, and a phosphate compound.

[0016] In one embodiment, the adhesive comprises a capsule that generates gas at the high temperature, and the capsule may comprise a shell comprising a thermoplastic resin and a hydrocarbon that exists in a liquid state inside the shell and vaporizes at the high temperature.

[0017] In one embodiment, the adhesive may bond the battery assembly and the pack frame.

[0018] In one embodiment, the adhesive may bond the battery assembly and the pack cover.

[0019] In one embodiment, the adhesive may bond between the pack frame and the lower surface of the battery assembly and between the upper surface of the battery assembly and the pack cover.

[0020] In one embodiment, it may further include an insulating layer provided between the adhesive and the battery assembly.

[0021] In one embodiment, the insulation layer may comprise heat-resistant plastic or mica.

[0022] In one embodiment, the battery assembly may be provided in a plurality, and the adhesive may be provided in a plurality spaced apart from each other so as to correspond to each of the plurality of battery assemblies.

[0023] In one embodiment, the pack frame has a shape with an open top, and the pack frame may cover the top of the pack frame.

[0024] In one embodiment, the pack frame and the pack cover may comprise metal.

[0025] A device according to one embodiment of the present invention includes the battery pack.

[0026] According to embodiments of the present invention, by fixing a battery assembly inside a battery pack using an adhesive whose adhesive strength decreases at high temperatures, partial replacement and repair of the battery pack are possible in the event of a defect in the battery assembly.

[0027] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0028] FIG. 1 is a perspective view of a battery pack according to one embodiment of the present invention.

[0029] Figure 2 shows a plan view of the battery pack of Figure 1.

[0030] Figure 3 shows a side view of the battery pack of Figure 1.

[0031] Figure 4 shows an exploded perspective view of the battery pack of Figure 1.

[0032] FIG. 5 illustrates an additional example of an exploded perspective view of the battery pack of FIG. 1.

[0033] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0034] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0035] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0036] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0037] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0038] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0039] FIG. 1 is a perspective view of a battery pack according to one embodiment of the present invention.

[0040] Figure 2 shows a plan view of the battery pack of Figure 1.

[0041] Figure 3 shows a side view of the battery pack of Figure 1.

[0042] Figure 4 shows an exploded perspective view of the battery pack of Figure 1.

[0043] Referring together to FIGS. 1 to 4, a battery pack (1000) according to one embodiment of the present invention comprises a battery assembly (100) including a plurality of battery cells, a pack frame (1100) having one side open and on which the battery assembly (100) is mounted, a pack cover (1200) covering the open side of the pack frame (1100), and an adhesive (1300) for joining the battery assembly (100) and the pack frame (1100).

[0044] The battery assembly (100) includes a plurality of battery cells. The battery cells according to the present embodiment may be of various shapes, for example, pouch-type battery cells, prismatic battery cells, or cylindrical battery cells. For example, FIG. 4 illustrates that the battery assembly (100) includes cylindrical battery cells. The cylindrical battery cells may be arranged along the xy plane while standing upright so that the sides of the main body face each other. Additionally, the electrode terminals of the cylindrical battery cells may protrude along the +z direction. However, the battery cells according to the present embodiment are not limited to a cylindrical type, and various types of battery cells may be applied.

[0045] The battery assembly (100) may be provided in multiple numbers. As an example, FIG. 4 illustrates that three battery assemblies (100) are provided. For example, the battery assembly (100) may include a first battery assembly (100a), a second battery assembly (100b), and a third battery assembly (100c), and each of the first to third battery assemblies (100a, 100b, 100c) may have a shape extended in the +y direction and may be arranged adjacently in the +x direction. However, not limited thereto, the battery assembly (100) may be provided in one, two, or four or more numbers.

[0046] Although not illustrated, the battery assembly (100) may include a busbar frame assembly. The busbar frame assembly may include a busbar, a busbar frame on which the busbar is placed, and a printed circuit board. The printed circuit board is connected to the electrode terminals of the battery cells or to the busbar to sense voltage data of each battery cell and transmit it externally. The busbar frame assembly may electrically connect the battery cells in series or in parallel.

[0047] The battery assembly (100) can be housed in a pack frame (1100).

[0048] The pack frame (1100) according to the present embodiment has a shape that wraps around the lower surface (-z direction) of the battery assembly (100) and has one side open. The pack frame (1100) protects the battery assembly (100) and the electrical components connected thereto from external physical impact. The pack frame (1100) may include a portion with high thermal conductivity to rapidly dissipate heat generated in the internal space to the outside. For example, at least a portion of the pack frame (1100) may be made of a metal with high thermal conductivity, such as aluminum, gold, silver, copper, platinum, or an alloy containing these, but is not limited thereto. Additionally, the pack frame (1100) may have partial electrical insulation, and an insulating film may be provided or an insulating coating may be applied at locations where insulation is required.

[0049] The pack frame (1100) may include a bottom portion (1110) on which a battery assembly (100) is placed and a side beam (1120) extending along the edge of the bottom portion (1110). This side beam (1120) may extend in a direction perpendicular to one side of the bottom portion (1110). By the bottom portion (1110) and the side beam (1120), an internal space with an open top is provided, and the battery assembly (100) can be housed in this internal space.

[0050] The pack cover (1200) according to the present embodiment covers one open side of the pack frame (1100). For example, the pack cover (1200) covers the open upper side of the pack frame (1100). Additionally, the pack cover (1200) can cover the upper surface of the battery assembly (100) mounted on the pack frame (1100).

[0051] The adhesive (1300) according to the present embodiment bonds at least one of the battery assembly (100) and the pack frame (1100) and the battery assembly (100) and the pack cover (1200).

[0052] In one embodiment, the adhesive (1300) joins the battery assembly (100) and the pack frame (1100). Also in one embodiment, the adhesive (1300) joins the battery assembly (100) and the pack cover (1200). Also in one embodiment, the adhesive (1300) joins the battery assembly (100) and the pack frame (1100) and the battery assembly (100) and the pack cover (1200).

[0053] Specifically, the adhesive (1300) may include an upper adhesive (1301) that bonds the upper surface (+z direction) of the battery assembly (100) and the pack cover (1200), and a lower adhesive (1302) that bonds the pack frame (1100) and the lower surface (-z direction) of the battery assembly (100). That is, the adhesive (1300) may be provided on the upper and lower surfaces of the battery assembly (100) to bond the battery assembly (100) to the pack frame (1100) and the pack cover (1200). Additionally, although not illustrated, the adhesive (1300) may also be provided between the side of the battery assembly (100) and the pack frame (1100) as needed.

[0054] In this way, the present invention does not introduce mechanical components and combines the battery assembly (100) with the pack frame (1100) and the pack cover (1200) using only an adhesive (1300), thereby reducing the space occupied by the mechanical components in the past, reducing the weight of the battery pack (1000), and increasing the energy density of the battery pack (1000).

[0055] Additionally, the adhesive (1300) can absorb vibrations and shocks that may occur inside the battery pack (1000). Specifically, it can prevent the battery assembly (100) from moving or detaching from the battery pack (1000) due to external shocks or vibrations. Through this, stable placement of the battery assembly (100) is possible, and the physical rigidity of the battery pack (1000) can be maintained.

[0056] Meanwhile, each of the upper adhesive (1301) and the lower adhesive (1302) is provided in a spaced-apart plurality to correspond to each of the plurality of battery assemblies (100). Specifically, the upper adhesive (1301) may be provided in three portions corresponding to the upper surface (+z direction) of the first to third battery assemblies (100a, 100b, 100c). The lower adhesive (1302) may be provided in three portions corresponding to the lower surface (-z direction) of the first to third battery assemblies (100a, 100b, 100c). Accordingly, the adhesive provided on the upper and lower surfaces of the first battery assembly (100a), the adhesive provided on the upper and lower surfaces of the second battery assembly (100b), and the adhesive provided on the upper and lower surfaces of the third battery assembly (100c) are spaced apart from each other and are independent. Each of the upper adhesive (1301) and the lower adhesive (1302) is provided independently according to the number of battery assemblies (100) provided, not limited to FIG. 4. Additionally, FIG. 4 illustrates, as an example, that the adhesive (1300) includes both the upper adhesive (1301) and the lower adhesive (1302), but the present embodiment is not limited thereto. For example, in one embodiment, the adhesive (1300) of the present invention may include only the upper adhesive (1301) and be used to bond the battery assembly (100) and the pack frame (1100). Also, in one embodiment, the adhesive (1300) may include only the lower adhesive (1302) and be used to bond the battery assembly (100) and the pack cover (1200).

[0057] The adhesive (1300) according to the present embodiment has reduced adhesive strength at high temperatures of 130°C or higher. Accordingly, when a defect occurs in a first battery assembly (100a), which is, for example, part of a battery assembly (100) in a battery pack that has been manufactured, the first battery assembly (100a) can be replaced by applying heat only to the adhesive (1300) provided to the first battery assembly (100a). Accordingly, partial replacement and repair of the battery pack (1000) is possible.

[0058] The method of applying heat only to the adhesive (1300) is to apply heat to the adhesive (1300) from the outside of the pack frame (1100) and the pack cover (1200). Since the pack frame (1100) and the pack cover (1200) contain metal, heat can be easily transferred to the adhesive (1300) inside even if heat is applied from the outside of the battery pack (1000). Meanwhile, as described above, the adhesive (1300) is provided independently to each of the multiple battery assemblies (100a, 100b, 100c), so the adhesive strength can be reduced by applying heat only to the adhesive (1300) provided to the first battery assembly (100a) that requires replacement.

[0059] In one embodiment, the adhesive (1300) may be formed from a thermoplastic resin. The adhesive (1300) containing the thermoplastic resin does not change its physical properties at room temperature, but when a high temperature of 130°C or higher is applied, the thermoplastic resin melts and the adhesive strength may decrease.

[0060] In one embodiment, the adhesive (1300) may include an intumescent material that expands in volume at high temperatures. The intumescent material may include at least one of a hydrated alkali metal silicate, a polyhydric alcohol, a carbohydrate, a melamine compound, a urea compound, and a phosphate compound. When the adhesive (1300) containing the intumescent material is exposed to heat and becomes high, a carbonized layer may form, causing the volume to expand and the adhesive strength to decrease.

[0061] In one embodiment, the adhesive (1300) may include a capsule that generates gas at high temperatures. For example, the capsule may include a foaming agent material. Specifically, the capsule may include a shell containing a thermoplastic resin and a hydrocarbon that exists in a liquid state inside the shell and vaporizes at high temperatures. The adhesive (1300) containing the capsule does not operate at room temperature, but when a high temperature of 130°C or higher is applied, the shell melts and the liquid hydrocarbon inside vaporizes into gas. The adhesive (1300) may expand due to the pressure generated at this time, and the adhesive strength may decrease.

[0062] The adhesive (1300) of the present invention comprises a thermoplastic resin, a volume-expanding material, or a capsule that generates gas at high temperatures as described above, and its adhesive strength decreases at high temperatures of 130°C or higher. The battery pack (1000) of the present invention uses the adhesive (1300) of the present invention to fix the battery assembly (100), so that if necessary, the adhesive (1300) can be melted and a part of the battery assembly (100) can be replaced. Accordingly, the usability of the battery pack (1000) can be improved.

[0063] Meanwhile, to prevent the battery assembly (100) from being thermally damaged during the process of applying heat to the adhesive (1300), the battery pack (1000) may further include an insulating layer.

[0064] FIG. 5 illustrates an additional example of an exploded perspective view of the battery pack of FIG. 1.

[0065] Referring to FIG. 5, the battery pack (1000) according to the present embodiment may further include an insulating layer (1400) provided between the adhesive (1300) and the battery assembly (100). The insulating layer (1400) may include heat-resistant plastic or Mica and may be provided in the shape of a case or film. Alternatively, the insulating layer (1400) may be an adhesive containing an insulating material.

[0066] The insulation layer (1400) may include an upper insulation layer (1401) provided between the upper adhesive (1301) and the upper surface (+z direction) of the battery assembly (100), and a lower insulation layer (1402) provided between the lower adhesive (1302) and the lower surface (-z direction) of the battery assembly (100). In FIG. 5, the upper insulation layer (1401) and the lower insulation layer (1402) are each shown as being provided in a spaced-apart plurality corresponding to a plurality of battery assemblies (100), but are not limited thereto and may be provided in a single shape. Also, in FIG. 5, the insulation layer (1400) is shown as including the upper insulation layer (1401) and the lower insulation layer (1402), but is not limited thereto and the insulation layer (1400) may be provided in a form that wraps around the battery assembly (100).

[0067] According to another embodiment of the present invention, a device including a battery pack (1000) is provided.

[0068] The battery pack (1000) can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0069]

[0070] 100: Battery assembly

[0071] 1000: Battery pack

[0072] 1100: Pack Frame

[0073] 1110: Bottom part

[0074] 1120: Side beam

[0075] 1200: Pack Cover

[0076] 1300: Adhesive

[0077] 1301: Top adhesive

[0078] 1302: Bottom adhesive

[0079] 1400: Insulation layer

[0080] 1401: Upper insulation layer

[0081] 1402: Lower insulation layer

Claims

1. A battery assembly comprising a plurality of battery cells; A pack frame having one side open and on which the battery assembly is mounted; A pack cover covering one open side of the above pack frame; and An adhesive that bonds at least one of the battery assembly and the pack frame and the battery assembly and the pack cover; comprising A battery pack in which the adhesive strength decreases at high temperatures of 130°C or higher.

2. In Paragraph 1, The above adhesive is a battery pack comprising a thermoplastic resin.

3. In Paragraph 1, The adhesive above includes an expandable material that expands in volume at high temperatures, and A battery pack in which the above-mentioned expandable material comprises at least one of a hydrated alkali metal silicate, a polyhydric alcohol, a carbohydrate, a melamine compound, a urea compound, and a phosphate compound.

4. In Paragraph 1, The above adhesive includes a capsule that generates gas at the high temperature, and The above capsule is a battery pack comprising a shell containing a thermoplastic resin and a hydrocarbon existing in a liquid state inside the shell and vaporizing at high temperatures.

5. In Paragraph 1, A battery pack in which the adhesive above bonds the battery assembly and the pack frame.

6. In Paragraph 1, A battery pack in which the adhesive above bonds the battery assembly and the pack cover.

7. In Paragraph 1, A battery pack in which the adhesive bonds between the pack frame and the lower surface of the battery assembly and between the upper surface of the battery assembly and the pack cover.

8. In Paragraph 1, A battery pack further comprising an insulating layer provided between the adhesive and the battery assembly.

9. In Paragraph 8, A battery pack in which the above-mentioned insulation layer comprises heat-resistant plastic or mica.

10. In Paragraph 1, A battery pack in which the battery assemblies are provided in plurality, and the adhesive is provided in plurality spaced apart from each other so as to correspond to each of the plurality of battery assemblies.

11. In Paragraph 1, A battery pack in which the above pack frame has an open top shape, and the above pack frame covers the top of the above pack frame.

12. In Paragraph 1, A battery pack in which the above pack frame and the above pack cover comprise metal.

13. A device comprising a battery pack according to paragraph 1.

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