Battery packs and devices containing such battery packs

Abstract

A battery pack according to an embodiment of the present invention includes: a pack frame on which a plurality of battery modules are mounted; an internal frame located inside the pack frame and partitioning the plurality of battery modules from each other; and at least one lifting portion located between the internal frame and the upper portion of the pack frame, wherein at least one of the lifting portions is deformed according to the temperature inside the pack frame.

Description

[Technical Field]

[0001] The present invention relates to a battery pack and a device including the battery pack, and more particularly to a battery pack and a device including the battery pack that can maintain the structure of the battery pack when a thermal runaway or heat propagation phenomenon occurs inside the battery pack. [Background technology]

[0002] Secondary batteries, which are easily applicable to various products and have electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles or hybrid vehicles powered by electrical sources, power storage devices, etc. These secondary batteries are attracting attention as a new energy source that is environmentally friendly and improves energy efficiency because they do not produce any by-products due to energy use, in addition to their primary advantage of dramatically reducing the use of fossil fuels.

[0003] Currently, commercial secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, extremely low self-discharge rate, and high energy density.

[0004] Generally, lithium secondary batteries can be classified according to the shape of the exterior material into cylindrical or prismatic secondary batteries in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries in which an electrode assembly is housed in an aluminum laminate sheet pouch.

[0005] In recent years, the use of secondary batteries as energy storage sources has led to an increasing need for large-capacity secondary battery structures, and this has led to an increasing demand for battery packs with medium- to large-sized modular structures that assemble battery modules in which multiple secondary batteries are connected in series or parallel. Such battery modules improve capacity and output by connecting multiple battery cells in series or parallel to each other to form a battery cell stack. Furthermore, multiple battery modules can be mounted together with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack.

[0006] Because battery packs are made up of multiple battery modules, if some of the battery modules experience overvoltage, overcurrent, or overheating, the safety and operating efficiency of the battery pack may become an issue. In particular, as battery pack capacity gradually increases to improve driving distance, the energy inside the pack also increases. As such, it is necessary to design a structure that meets stricter safety standards and ensures the safety of the vehicle and driver.

[0007] In relation to this, when thermal runaway or heat propagation occurs within a battery pack, high-temperature gases and particles inside the battery pack may cause deformation of the battery pack's components. In particular, in such a high-temperature environment, the lid, which is the upper pack frame of the battery pack, may be structurally deformed, such as sagging in the direction of gravity, which may cause the upper vent passage of the battery pack to become clogged. If the upper vent passage of the battery pack becomes clogged, the release of high-temperature gases and particles inside the battery pack may be delayed, which may lead to an explosion or fire of the battery pack. Therefore, to prevent such situations from occurring, there is a need to develop a battery pack that can prevent clogging of the upper vent passage of the battery pack and minimize damage even when thermal runaway or heat propagation occurs inside the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a battery pack and a device including the battery pack that can maintain the structure of the battery pack when a thermal runaway or heat propagation phenomenon occurs inside the battery pack.

[0009] The problems to be solved by the present invention are not limited to those described above, and problems not mentioned above will be clearly understood by those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Means for solving the problem]

[0010] A battery pack according to one embodiment of the present invention includes: a pack frame in which a plurality of battery modules are mounted; an inner frame located inside the pack frame and separating the plurality of battery modules from each other; and at least one lifting part located between the inner frame and an upper part of the pack frame, wherein the at least one lifting part is deformed in response to a temperature inside the pack frame.

[0011] The lifting portion may include a lifting member that bends toward an upper portion of the pack frame when the temperature inside the pack frame rises.

[0012] The lifting unit may further include at least one fixing member for fixing the lifting member to the inner frame.

[0013] The fixing member may be a bolting member, and the lifting member and the inner frame may be bolted together.

[0014] The lifting member may be configured such that a portion located between portions fixed by the fixing member bends in a direction toward the upper portion of the pack frame.

[0015] The lifting member may extend along a width direction of the battery module.

[0016] The inner frame may include at least one horizontal beam extending along the width direction of the battery module and at least two vertical beams extending along the length direction of the battery module, and at least one of the lifting portions may extend along the same direction as the horizontal beam.

[0017] At least one of the lifting portions may include a pair of lifting portions spaced apart from each other, and the pair of lifting portions may be located between the horizontal beam and one side of the lower pack frame facing the horizontal beam.

[0018] At least one of the lifting portions may be located on at least two of the vertical beams, and the fixing member may fix the lifting member to each of the at least two vertical beams.

[0019] The lifting member may have a shape in which an upper portion of the lifting member is made of a relatively larger amount of material than a lower portion of the lifting member.

[0020] The lifting member may have one of a V-shaped, U-shaped, T-shaped, inverted triangular, and semicircular cross section.

[0021] The lifting member may be made of steel.

[0022] A device according to another embodiment of the present invention includes the battery pack described above. [Effects of the Invention]

[0023] According to an embodiment, the battery pack of the present invention and a device including the battery pack include a lifting member between the upper pack frame and the inner frame of the battery pack, and can maintain the structure of the battery pack when a thermal runaway or heat propagation phenomenon occurs inside the battery pack.

[0024] The effects of the present invention are not limited to those described above, and effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view showing a battery pack according to an embodiment of the present invention; [Figure 2] 2 is an exploded perspective view of components included in the battery pack of FIG. 1. FIG. [Figure 3] 2 is a perspective view showing the structure of the battery pack of FIG. 1 with an upper pack frame and a plurality of battery modules removed. FIG. [Figure 4] 2 is a diagram showing the shape of a lifting member included in the battery pack of FIG. 1; [Figure 5] 4 is a diagram showing a part of a cross section taken along the a-a' axis in FIG. 3. [Figure 6] 4 is a diagram showing a part of a cross section taken along the bb' axis of FIG. 3. [Figure 7] 4 is a diagram showing a part of a cross section taken along the bb' axis of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement various embodiments of the present invention. The present invention can be embodied in several different forms and is not limited to the examples described herein.

[0027] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0028] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0029] Also, throughout the specification, when a part is said to "comprise" a certain element, this means that it can further include other elements, rather than excluding other elements, unless otherwise specified.

[0030] Furthermore, throughout the specification, "on a plane" means a view of the target part from above, and "on a cross section" means a view of the target part cut vertically from the side.

[0031] Hereinafter, a battery pack according to an embodiment of the present invention will be described.

[0032] Fig. 1 is a perspective view showing a battery pack according to an embodiment of the present invention. Fig. 2 is an exploded perspective view of components included in the battery pack of Fig. 1. Fig. 3 is a perspective view showing the structure of the battery pack of Fig. 1 with an upper pack frame and multiple battery modules removed.

[0033] Referring to Figures 1 and 2, a battery pack according to one embodiment of the present invention includes pack frames 1100, 1200 in which multiple battery modules are mounted, and an inner frame 1300 located inside the pack frames 1100, 1200 and separating the multiple battery modules 100 from each other.

[0034] Here, the pack frames 1100 and 1200 may include a lower pack frame 1100 on which a plurality of battery modules 100 are mounted and an upper pack frame 1200 located on top of the battery modules 100. More specifically, the upper pack frame 1200 may cover the upper part of the lower pack frame 1100 when a plurality of battery modules 100 are mounted on the lower pack frame 1100. Here, the lower pack frame 1100 and the upper pack frame 1200 may be joined at their contacting surfaces by a method such as welding or adhesive bonding, thereby sealing the inside of the battery pack 1000.

[0035] 1 to 3, the lower pack frame 1100 may include an outer frame 1110 extending from the bottom surfaces of the pack frames 1100 and 1200 toward the upper pack frame 1200, and a pack bottom 1150 facing the lower surface of the battery module 100. That is, the outer frame 1110 may extend from the pack bottom 1150 toward the upper pack frame 1200.

[0036] In the lower pack frame 1100, the outer frame 1110 and the pack bottom 1150 may be integrated with each other or may be fixed by a separate fastening method such as welding or adhesive.

[0037] As one example, the outer frame 1110 may be made of a heat insulating material. As another example, the outer frame 1110 may be made of a dissimilar metal bonding material such as clad metal, or may be a structure containing a heat insulating material such as aerogel or EPP (Expanded Polypropylenes) foam. As another example, the outer frame 1110 may be a structure containing a material such as silicon foam, mica, or glass fiber pad. However, the outer frame 1110 is not limited thereto, and any heat insulating material having a predetermined rigidity may be used as the outer frame 1110.

[0038] The lower pack frame 1100 may also include an inner frame 1300 located within the outer frame 1110 and extending from the pack bottom 1150 to the upper pack frame 1200. More specifically, the inner frame 1300 includes at least one horizontal beam 1310 and at least two vertical beams 1350.

[0039] The horizontal beam 1310 may extend along the width direction (x-axis direction) of the battery module 100. In addition, the vertical beam 1350 may be located between one side of the external frame 1110 and the horizontal beam 1310 and extend along the length direction (y-axis direction) of the battery module 100. Here, one side of the external frame 1110 may refer to the side of the external frame 1110 facing the horizontal beam 1310.

[0040] The plurality of battery modules 100 may be separated from each other by at least one horizontal beam 1310 and at least two vertical beams 1350. That is, the internal space separated by the at least one horizontal beam 1310 and at least two vertical beams 1350 may be a module area where the battery modules 100 are respectively mounted, and may also be an area where other electrical components are mounted in addition to the battery modules 100.

[0041] However, the configuration of the inner frame 1300 is not limited thereto, and any configuration that can separate and mount a plurality of battery modules 100 from one another can be included in this embodiment. In addition, the length, spacing, number, etc. of the at least one horizontal beam 1310 and the at least two vertical beams 1350 can be adjusted depending on the size and arrangement of the battery modules 100.

[0042] As an example, the inner frame 1300 may be made of a heat insulating material. As another example, the inner frame 1300 may be made of a dissimilar metal bonding material such as clad metal, or may be a structure containing a heat insulating material such as aerogel or EPP (Expanded Polypropylenes) foam. As another example, the inner frame 1300 may be a structure containing a material such as silicon foam, mica, or glass fiber padding. However, the inner frame 1300 is not limited thereto, and any heat insulating material having a predetermined rigidity may be used as the inner frame 1300.

[0043] As a result, in the battery pack 1000 according to this embodiment, the lower pack frame 1100 allows the plurality of battery modules 100 to be spaced apart by being separated from each other by the outer frame 1110 and the inner frame 1300, and even if a fire occurs in some of the plurality of battery modules 100, heat propagation between adjacent battery modules 100 can be effectively prevented.

[0044] 2, a battery pack 1000 according to this embodiment may include a plurality of battery modules 100. Here, the battery modules 100 may be mounted on a lower pack frame 1100. More specifically, the plurality of battery modules 100 may be mounted in areas defined by an outer frame 1110 and an inner frame 1300, respectively, as shown in FIGS. 2 and 3. However, the arrangement direction of the battery modules 100 is not limited thereto and may be appropriately changed as needed.

[0045] As an example, the battery module 100 includes a battery cell stack (not shown) in which a plurality of battery cells are stacked, and a module frame (not shown) that houses the battery cell stack (not shown).

[0046] The battery cell is preferably a pouch-type battery cell. For example, the battery cell may be manufactured by housing an electrode assembly in a pouch case made of a laminate sheet including a resin layer and a middle layer, and then heat-sealing the sealing portion of the pouch case. The battery cell may be formed in a rectangular sheet structure. The battery cell may be configured in multiple units, and the multiple battery cells may be stacked to be electrically connected to each other to form a battery cell stack (not shown). Here, the number of battery cells constituting the battery cell stack (not shown) may be adjusted as needed.

[0047] The module frame (not shown) may include an upper cover and a U-shaped frame. The U-shaped frame may include a bottom and two side portions extending upward from both ends of the bottom. The bottom may cover the lower surface of the battery cell stack (not shown), and the side portions may cover the side surfaces of the battery cell stack (not shown). The upper cover may be joined to the U-shaped frame by welding or the like with corresponding corners in contact with each other, thereby forming a structure that covers the top, bottom, left, and right of the battery cell stack (not shown). For this reason, the upper cover and the U-shaped frame may be made of a metal material having a predetermined strength.

[0048] However, the structure of the module frame (not shown) is not limited thereto, and in another embodiment, the module frame (not shown) may have a mono-frame structure. Here, the mono-frame may be in the form of a metal plate with an integrated top, bottom, and both side surfaces. The mono-frame may be manufactured by extrusion molding. Furthermore, the module frame (not shown) may have an L-frame structure in addition to a mono-frame or U-frame structure, and may also have various structures not described in the above examples.

[0049] The battery module 100 further includes bus bar frames located on the front and rear surfaces of the battery cell stack (not shown), and end plates covering the bus bar frames. Here, bus bars (not shown) electrically connected to the battery cell stack (not shown) may be located on the bus bar frames. As a result, the end plates can physically protect the battery cell stack (not shown) and other electrical components from external impacts.

[0050] Hereinafter, the lifting unit 1400 included in the battery pack 1000 according to an embodiment of the present invention will be mainly described.

[0051] 2 and 3, the battery pack 1000 according to an embodiment of the present invention may include at least one lifting unit 1400 located between the inner frame 1300 and the upper portions of the pack frames 1100 and 1200. More specifically, the at least one lifting unit 1400 may be located between the inner frame 1300 and the upper pack frame 1200. That is, the at least one lifting unit 1400 may be located in a space where the inner frame 1300 and the upper pack frame 1200 are spaced apart from each other.

[0052] At least one lifting part 1400 may extend along the width direction (x-axis direction) of the battery module 100. More specifically, at least one lifting part 1400 may extend along the same direction (x-axis direction) as the horizontal beam 1310. Here, the lifting part 1400 may extend between one side and the other side of the outer frames 1110 that are positioned facing each other of the lower pack frame 1100.

[0053] 2 and 3, the at least one lifting unit 1400 may include a pair of lifting units 1400. Here, the pair of lifting units 1400 may be located between the horizontal beam 1310 and one side of the lower pack frame 1100 facing the horizontal beam 1310. Also, the pair of lifting units 1400 may be located spaced apart from each other.

[0054] However, the number and arrangement of the lifting parts 1400 are not limited to this, and any number and / or arrangement that can prevent sagging of the upper pack frame 1200 of the battery pack 1000 when thermal runaway occurs inside the battery pack 1000 can be included in this embodiment.

[0055] The lifting unit 1400 may include a lifting member 1410 that bends toward the upper part of the pack frames 1100, 1200 when the temperature inside the pack frames 1100, 1200 rises. More specifically, the lifting member 1410 may be made of a material that expands in length when the temperature inside the pack frames 1100, 1200 rises. In addition, as will be described later, the lifting member 1410 is fixed to the inner frame 1300 by a fixing member 1450, so that the lifting member 1410 can bend toward the upper pack frame 1200 when it expands in length.

[0056] For example, the lifting member 1410 may be made of a material that expands at temperatures from room temperature to 1500 degrees Celsius or less. Here, room temperature refers to a temperature between 15 degrees Celsius and 25 degrees Celsius, and may have the same meaning as commonly used room temperature.

[0057] As a result, in the battery pack 1000 according to this embodiment, the upper pack frame 1200 can be supported within a temperature range ranging from room temperature, which is the typical usage environment for the battery pack 1000, to a high-temperature environment in which thermal runaway occurs within the battery pack 1000, and sagging due to structural deformation of the upper pack frame 1200 can be prevented.

[0058] The lifting members 1410 may extend along the width direction (x-axis direction) of the battery module 100. More specifically, the lifting members 1410 may extend along the same direction (x-axis direction) as the horizontal beams 1310. Here, the lifting members 1410 may extend between one side and the other side of the outer frames 1110 that are positioned facing each other of the lower pack frame 1100.

[0059] 2 and 3, the lifting members 1410 may include a pair of lifting members 1410. Here, the pair of lifting members 1410 may be located between the horizontal beam 1310 and one side of the lower pack frame 1100 facing the horizontal beam 1310. Also, the pair of lifting members 1410 may be located spaced apart from each other.

[0060] However, the number and arrangement of the lifting members 1410 are not limited to this, and any number and / or arrangement that can prevent sagging of the upper pack frame 1200 of the battery pack 1000 when thermal runaway occurs inside the battery pack 1000 can be included in this embodiment.

[0061] 4 is a diagram showing the shape of a lifting member included in the battery pack of FIG. 1. The lifting member 1410 may have a shape in which the upper portion of the lifting member 1410 has a relatively larger material content than the lower portion. In other words, the lifting member 1410 has a shape in which the upper portion of the lifting member 1410 has a relatively larger area than the lower portion of the lifting member 1410 in the vertical direction of the lifting member 1410. For example, as shown in FIG. 4, the lifting member 1410 may have one of a V-shaped, U-shaped, T-shaped, inverted triangular, and semicircular cross section.

[0062] As a result, the lifting member 1410 can bend in a portion where there is a relatively large amount of material in a high-temperature environment caused by a temperature rise inside the battery pack 1000. In other words, the lifting member 1410 can bend toward the upper portion, which is a relatively wide area based on the vertical direction of the lifting member 1410. That is, the lifting member 1410 can bend toward the upper portion of the lifting member 1410, i.e., the lifting member 1410 can bend in a direction toward the upper pack frame 1200.

[0063] However, the shape of the lifting member 1410 is not limited to this, and any shape that can bend toward the top of the pack frames 1100 and 1200 in a high-temperature environment due to a rise in temperature inside the battery pack 1000 can be included in this embodiment.

[0064] As an example, the lifting member 1410 may be made of steel, but is not limited thereto, and may be made of any material that is heat-resistant and bends toward the top of the pack frames 1100 and 1200 in a high-temperature environment caused by a temperature rise inside the battery pack 1000.

[0065] FIG. 5 is a drawing showing a part of a cross section taken along the aa' axis in FIG.

[0066] 3 to 5, the lifting unit 1400 may include at least one fixing member 1450 for fixing the lifting member 1410 to the inner frame 1300. More specifically, at least one fixing member 1450 is disposed at each of the positions where the lifting member 1410 and the inner frame 1300 contact each other, thereby fixing the lifting member 1410 and the inner frame 1300 to each other. For example, as shown in FIG. 3, the at least one lifting member 1410 is positioned on at least two vertical beams 1350, and at least one fixing member 1450 fixes the at least one lifting member 1410 to each of the at least two vertical beams 1350. That is, in the battery pack 1000 according to this embodiment, the lifting member 1410 may not be fixed to the upper pack frame 1200.

[0067] For example, the fixing member 1450 may be a bolting member, and the lifting member 1410 may be bolted to the inner frame 1300. However, the method and shape of the fixing member 1450 are not limited thereto, and any method and shape that can fix the lifting member 1410 to the inner frame 1300 may be included in this embodiment.

[0068] 6 and 7 are drawings showing a part of a cross section cut along the bb' axis of FIG.

[0069] 5 and 6, the lifting part 1400 may not undergo structural deformation in the normal state of the battery pack 1000. In contrast, when the temperature inside the pack frames 1100 and 1200 rises, the lifting part 1400 may bend in a direction toward the upper part of the pack frames 1100 and 1200, as shown in FIG. 7. That is, the lifting part 1400 may bend in a direction toward the upper pack frame 1200.

[0070] That is, the lifting member 1410 can expand in the length direction in a high temperature environment caused by an increase in temperature inside the battery pack 1000. Here, since a portion of the lifting member 1410 is fixed to the inner frame 1300 by the fixing member 1450, the lifting member 1410 can bend toward the upper pack frame 1200 by expanding in the length direction.

[0071] More specifically, the portions of the lifting member 1410 located between the portions secured by the fixing members 1450 can bend in a direction toward the upper portions of the pack frames 1100, 1200. That is, the portions of the lifting member 1410 located between the portions secured by the fixing members 1450 can bend in a direction toward the upper pack frame 1200.

[0072] As a result, in the battery pack 1000 according to this embodiment, the bending direction of the lifting part 1400 is guided toward the upper pack frame 1200, and the lifting part 1400 can support the upper pack frame 1200, thereby increasing the structural rigidity of the battery pack 1000.

[0073] In addition, the lifting unit 1400 prevents sagging caused by structural deformation of the upper pack frame 1200, and the lifting unit 1400 can prevent clogging of the gas venting passage formed between the upper pack frame 1200 and the plurality of battery modules 100. That is, in the battery pack 1000 according to this embodiment, even when a thermal runaway phenomenon occurs inside the battery pack 1000, the gas generated inside the battery pack 1000 can be easily discharged to the outside, thereby preventing or delaying additional heat propagation or explosion.

[0074] A device according to another embodiment of the present invention includes the battery pack described above. Such devices are applicable to transportation means such as electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto and can be applied to various devices that can use battery modules and battery packs including the battery pack, and these are also within the scope of the present invention.

[0075] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the claims also fall within the scope of the present invention. [Explanation of symbols]

[0076] 100 Battery Module 1000 battery packs 1100 Lower Pack Frame 1200 Upper Pack Frame 1300 Internal Frame 1400 Lifting Section 1410 Lifting members 1450 Fixing member

Claims

1. a pack frame including a lower pack frame on which a plurality of battery modules are mounted and an upper pack frame located above the plurality of battery modules; an inner frame located inside the pack frame and separating the plurality of battery modules from each other; and at least one lifting portion located between the inner frame and the upper pack frame; At least one of the lifting portions is deformed in response to a temperature inside the pack frame; The battery pack, wherein the lifting portion includes a lifting member that bends toward the upper pack frame when the temperature inside the pack frame rises.

2. The battery pack of claim 1 , wherein the lifting portion further comprises at least one fixing member for fixing the lifting member to the inner frame.

3. the fixing member is a fastening member, The battery pack according to claim 2 , wherein the lifting member and the inner frame are fastened together.

4. 3. The battery pack according to claim 2, wherein the lifting member is configured so that a portion located between the portions fixed by the fixing member bends in a direction toward an upper portion of the pack frame.

5. The battery pack according to claim 2 , wherein the lifting member extends along a width direction of the battery module.

6. the inner frame includes at least one horizontal beam extending along a width direction of the battery module and at least two vertical beams extending along a length direction of the battery module; The battery pack according to claim 5 , wherein at least one of the lifting portions extends along the same direction as the horizontal beam.

7. At least one of the lifting portions includes a pair of lifting portions spaced apart from each other, The battery pack according to claim 6 , wherein the pair of lifting portions are located between the horizontal beam and one side surface of the lower pack frame facing the horizontal beam.

8. At least one of the lifting sections is located on at least two of the vertical beams; The battery pack according to claim 6 , wherein the fixing member fixes the lifting member to each of the at least two vertical beams.

9. The battery pack of claim 1 , wherein the lifting member has a shape in which an upper portion of the lifting member is made of a relatively larger amount of material than a lower portion of the lifting member.

10. The battery pack of claim 9 , wherein the lifting member has one of a V-shaped, U-shaped, T-shaped, inverted triangular, and semicircular cross section.

11. The battery pack according to claim 1 , wherein the lifting member is made of steel.

12. A device comprising the battery pack of any one of claims 1 to 11.

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