Battery packs and devices containing them

Abstract

A battery pack according to an embodiment of the present invention includes a battery module including a plurality of battery cells, a pack case for accommodating the battery module, and a pair of pressure members disposed in the pack case, the battery module being positioned between the pair of pressure members. The battery module is inserted between the pair of pressure members by an interference fit, and a pressure is applied to the battery module by the pair of pressure members.

Description

[Technical Field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0006426, filed January 17, 2022, and Korean Patent Application No. 10-2023-0006365, filed January 16, 2023, 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 and a device including the same, and more particularly to a battery pack having a high pressure structure for a battery cell and a device including the same. [Background technology]

[0003] In modern society, the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, leading to active development of technologies related to these mobile devices. Furthermore, rechargeable secondary batteries are being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and other vehicles as a solution to air pollution caused by conventional gasoline-powered vehicles that use fossil fuels, and this has led to an increased need for development of secondary batteries.

[0004] Generally, lithium secondary batteries can be classified into can-type 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 a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0005] While secondary batteries used in small devices typically have two to three battery cells, secondary batteries used in medium- to large-sized devices such as automobiles typically use battery modules in which multiple battery cells are electrically connected. These battery modules improve capacity and output by connecting multiple battery cells in series or parallel to form a stack of battery cells. Furthermore, one or more battery modules may be installed 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.

[0006] Meanwhile, secondary batteries may experience swelling or bleeding, a phenomenon in which the internal electrolyte decomposes and generates gas during repeated charge / discharge cycles or initial charge, causing the battery cell 110 to swell. In particular, pouch-type secondary batteries may experience more severe swelling than can-type secondary batteries because the structural rigidity of the exterior material is weaker.

[0007] FIG. 1 is a cross-sectional view showing a schematic cross section of a conventional battery module 10. As shown in FIG.

[0008] Referring to FIG. 1 , a conventional battery module 10 may include a plurality of battery cells 11 stacked in one direction and a module frame 40 that houses the battery cells 11. Such battery cells 11 may be pouch-type battery cells. When swelling occurs in the battery cells 11, the battery cells 11 expand mainly in the stacking direction. In the conventional battery module 10, compression pads 50 are disposed between the battery cells 11 or between the battery cells 11 and one surface of the module frame 40 to control the swelling of the battery cells 11.

[0009] As the capacity of battery cells increases, the degree of swelling also increases significantly, and the number of battery cells applied to a battery module also tends to gradually increase, so controlling the swelling of battery cells inside a battery module has become an important issue.

[0010] When swelling occurs in a battery cell, the pressure inside the battery increases, causing an increase in volume, which can have a negative impact on the structural stability of the battery module. Furthermore, the battery module 10 includes a large number of interconnected battery cells for high output or high capacity. If the volume of each battery cell increases even slightly due to swelling, the volume changes of the individual battery cells can add up to a serious level of deformation throughout the battery module. In particular, deformation of the module frame 40 that houses the large number of battery cells can occur, and damage to the welds of the module frame 40 can occur.

[0011] Even with the conventional compression pad 50, there are limitations to controlling swelling of the battery cell 11. In particular, all-solid-state batteries can be applied to pouch battery cells to realize high-capacity battery modules and battery packs. However, in the case of all-solid-state batteries, the degree of swelling is greater and a certain level of pressure must be applied to achieve battery performance. The conventional battery module 10 has a structure that makes it difficult to apply high pressure to the battery cells.

[0012] Therefore, a new battery pack structure is required that can effectively control swelling of the battery cells and apply a high level of pressure to the battery cells. Summary of the Invention [Problem to be solved by the invention]

[0013] An object of the present invention is to provide a battery pack having a structure capable of effectively controlling swelling of a battery cell and applying a high level of pressure to the battery cell, and a device including the same.

[0014] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, but may be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0015] A battery pack according to an embodiment of the present invention includes a battery module including a plurality of battery cells, a pack case that houses the battery module, and a pair of pressure members disposed in the pack case, with the battery module positioned between the pair of pressure members. The battery module is inserted between the pair of pressure members by an interference fit, and pressure is applied to the battery module by the pair of pressure members.

[0016] The pressure member may be an elastic member that applies pressure to the battery module.

[0017] The pressure member may have a leaf spring structure that protrudes in a direction in which the battery module is positioned.

[0018] The distance between the pair of pressure members may be equal to or narrower than the width of the battery module, so that the battery module can be forcibly inserted between the pair of pressure members.

[0019] The battery cells may be stacked in one direction within the battery module, and the pair of pressure members may be positioned on both sides of the battery module in the direction in which the battery cells are stacked.

[0020] The one direction in which the battery cells are stacked may be parallel to one surface of a bottom of the pack case.

[0021] The one direction in which the battery cells are stacked may be perpendicular to one surface of the bottom of the pack case.

[0022] The battery module may include a support frame facing the pair of pressure members.

[0023] The support frame may have a recessed shape corresponding to the protruding shape of the pressure member.

[0024] One surface of the support frame facing the pressing member may have a recessed shape, and the other surface facing the battery cell may have a flat shape.

[0025] At least one bearing ball is inserted into the support frame, so that the at least one bearing ball can rotate within the support frame.

[0026] A portion of at least one of the bearing balls may be exposed and protruded from one surface of the support frame toward the pressure member, so that the at least one bearing ball may come into contact with the pressure member.

[0027] The rotation of the at least one bearing ball allows the battery module to be coupled between the pair of pressure members in an interference fit.

[0028] The battery module may include a module frame that houses the battery cells, and the support frame may form both sides of the module frame.

[0029] The battery module may include a module frame that houses the battery cells, and the support frames may be attached to both sides of the module frame.

[0030] The battery pack may further include at least two vertical beams disposed in the pack case, and the pair of pressure members and the battery module may be positioned between a pair of adjacent vertical beams among the at least two vertical beams.

[0031] At least one bearing ball may be inserted into the pressure member, and the at least one bearing ball may rotate within the pressure member. A portion of the at least one bearing ball may be exposed and protrude toward the battery module, and the at least one bearing ball may contact the battery module.

[0032] The battery cell may be an all-solid-state battery.

[0033] A device according to an embodiment of the present invention includes the battery pack. [Effects of the Invention]

[0034] According to an embodiment of the present invention, a battery module is inserted between a pair of pressure members in an interference fit, and swelling of the battery cells included in the battery module can be effectively controlled to apply a high level of pressure to the battery cells.

[0035] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned above will be apparent to those skilled in the art from the claims. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 10 is a cross-sectional view schematically showing a cross section of a conventional battery module. [Figure 2] 1 is a perspective view showing a battery pack according to an embodiment of the present invention; [Figure 3] 3 is a perspective view showing a battery module included in the battery pack of FIG. 2. FIG. [Figure 4] 1 is a perspective view showing a battery cell stack according to an embodiment of the present invention; [Figure 5] 5 is a perspective view showing one of the battery cells included in the battery cell stack of FIG. 4. FIG. [Figure 6] FIG. 1 is a perspective view showing a support frame according to an embodiment of the present invention. [Figure 7]FIG. 7 is a plan view of the support frame of FIG. 6 as seen from above. [Figure 8] 4 is a partial view showing a first frame and a bearing ball according to an embodiment of the present invention. [Figure 9] 4 is a partial view showing a second frame according to an embodiment of the present invention. [Figure 10] FIG. 2 is a perspective side view of a pressure member according to an embodiment of the present invention. [Figure 11] FIG. 2 is a side view of a pressure member according to an embodiment of the present invention. [Figure 12] 1 is a plan view showing an arrangement of a battery cell stack, a support frame, and a pressure member according to an embodiment of the present invention. FIG. [Figure 13] FIG. 10 is an exploded perspective view showing a battery module according to another embodiment of the present invention. [Figure 14] FIG. 10 is a perspective view showing a battery pack according to another embodiment of the present invention, in which the stacking direction of the battery cells is different. [Figure 15] FIG. 10 is a perspective view showing a battery pack according to a modified embodiment of the present invention; [Figure 16] 16 is a plan view of a pressure member included in the battery pack of FIG. 15, as viewed from above. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0038] 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.

[0039] Furthermore, 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, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0040] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where it is "directly above" that 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. Furthermore, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" or "above" in the opposite direction of gravity.

[0041] Furthermore, throughout the specification, when a part "comprises" other elements, this means that it can further include other elements, not excluding the other elements, unless otherwise specified.

[0042] Also, throughout the specification, "in a plane" means a view of the subject matter as seen from above, and "in cross section" means a view of the subject matter as seen from the side of a vertical cross section.

[0043] Fig. 2 is a perspective view showing a battery pack according to an embodiment of the present invention, and Fig. 3 is a perspective view showing a battery module included in the battery pack of Fig. 2.

[0044] 2 and 3, a battery pack 1000 according to an embodiment of the present invention includes a battery module 100 including a plurality of battery cells 110, a pack case 1100 that houses the battery module 100, and a pair of pressure members 1200 disposed in the pack case 1100. The battery module 100 is positioned between the pair of pressure members 1200.

[0045] The battery module 100 is inserted between the pair of pressure members 1200 in a forced insertion manner, and pressure is applied to the battery module 100 by the pair of pressure members 1200 .

[0046] First, the battery module 100 according to this embodiment and the battery cells 110 included therein will be described in detail.

[0047] Figure 4 is a perspective view showing a battery cell stack according to an embodiment of the present invention. Figure 5 is a perspective view showing one of the battery cells included in the battery cell stack of Figure 4. Specifically, Figure 3 shows the battery cell stack 120, as well as a support frame 200 and an end plate 300, which will be described later, but for convenience of explanation, Figure 4 shows only the battery cell stack 120.

[0048] 2 to 5, the battery module 100 according to this embodiment may include a plurality of battery cells 110. As shown in FIG.

[0049] The battery cell 110 may be a pouch-type battery cell. For example, the battery cell 110 according to this embodiment has a structure in which two electrode leads 150 face each other and protrude from one end 114a and the other end 114b of the battery body 113, respectively. More specifically, the electrode leads 150 are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell 110.

[0050] Meanwhile, the battery cell 110 can be manufactured by bonding both ends 114a, 114b of the battery case 114 and one side 114c connecting them together while an electrode assembly (not shown) is housed in the battery case 114. In other words, the battery cell 110 according to this embodiment has a total of three sealing portions 114sa, 114sb, and 114sc, and the sealing portions 114sa, 114sb, and 114sc are sealed by a method such as heat sealing, and the remaining one side may be formed as a folding portion 115. In addition, the folding portion 115 may extend long along one edge of the battery cell 110.

[0051] FIG. 5 shows a bidirectional lead battery cell 110 in which two electrode leads 150 protrude in directions opposite to each other, but as another embodiment of the present invention, a unidirectional lead battery cell in which two electrode leads protrude in the same direction is also possible.

[0052] The battery cells 110 may be in the form of a sheet, and the battery cells 110 may be stacked in one direction to form a battery cell stack 120. Figure 4 shows a configuration in which a plurality of battery cells 110 are stacked in a direction parallel to the x-axis, so that the electrode leads 150 protrude in the y-axis direction and the -y-axis direction.

[0053] The battery module 100 according to this embodiment may include a support frame 200 facing a pair of pressing members 1200. Specifically, the support frame 200 is disposed adjacent to each of the outermost battery cells 110a, 110b of the battery cell stack 120. Depending on the stacking direction of the battery cells 110, the support frame 200 may be formed on both side surfaces of the battery module 100 as shown in the drawing.

[0054] Meanwhile, the battery module 100 may further include end plates 300 positioned between the support frames 200 and covering one and other sides of the battery cell stack 120. The one and other sides of the battery cell stack 120 may be surfaces of the battery cell stack 120 from which the electrode leads 150 protrude. Although not specifically shown, a bus bar frame and an insulating cover may be positioned between the end plates 300 and the battery cell stack 120. The bus bar frame is configured to mount bus bars for connecting the electrode leads 150 of each battery cell 110 to each other, and the insulating cover includes an electrically insulating material and is configured to block electrical connection between the battery cells 110 and the end plates 300.

[0055] The support frame 200 according to this embodiment will be described in detail below.

[0056] Fig. 6 is a perspective view showing a support frame according to an embodiment of the present invention, and Fig. 7 is a plan view of the support frame of Fig. 6 as seen from above.

[0057] 6 and 7, at least one bearing ball 230 may be inserted into the support frame 200 according to this embodiment. The at least one bearing ball 230 may rotate within the support frame 200.

[0058] Specifically, the support frame 200 may include a first frame 210 , a second frame 220 , and a bearing ball 230 positioned between the first frame 210 and the second frame 220 .

[0059] The first frame 210 and the second frame 220 may be plate-shaped members. The first frame 210 may face the outermost battery cells 110a and 110b of the battery cell stack 120, and the second frame 220 may face the pressing member 1200 (see FIG. 2). One side of the first frame 210 and one side of the second frame 220 may be spaced apart from each other by a predetermined distance, and a bearing ball 230 may be positioned therebetween.

[0060] Fig. 8 is a partial view showing a first frame and a bearing ball according to an embodiment of the present invention, and Fig. 9 is a partial view showing a second frame according to an embodiment of the present invention.

[0061] 8, a plurality of ribs 211 may be formed on the first frame 210 according to this embodiment. The ribs 211 may be integrally formed with the first frame 210 by extrusion molding. The ribs 211 are provided with receiving portions 211a in which the bearing balls 230 may be received. The bearing balls 230 according to this embodiment may be positioned rotatably in the spaces within the receiving portions 211a formed in the ribs 211 without being fixed.

[0062] 9, according to this embodiment, a through-hole 220H may be formed in the second frame 220. When the first frame 210 and the second frame 220 are combined, the through-hole 220H may be positioned to correspond to the bearing ball 230.

[0063] That is, the through-holes 220H of the second frame 220 are provided at positions corresponding to the receiving portions 211a of the first frame 210. When the first frame 210 and the second frame 220 are combined, the bearing balls 230 are disposed in the spaces between the receiving portions 211a and the through-holes 220H.

[0064] The diameter of the through-hole 220H is smaller than the diameter of the bearing ball 230, so that the bearing ball 230 does not fall out. However, a part of the bearing ball 230 may protrude outward from one surface of the support frame 200, particularly the second frame 220, through the through-hole 220H.

[0065] In summary, in this embodiment, at least one bearing ball 230 is rotatably disposed within the support frame 200, and a portion of at least one bearing ball 230 can be exposed and protrude from one surface of the support frame 200 in the direction of the pressure member 1200 (see FIG. 2). The second frame 220 is the surface facing the pressure member 1200 (see FIG. 2), and the protruding portion of the bearing ball 230 can come into contact with the pressure member 1200.

[0066] Meanwhile, the support frame 200 may further include a spring portion 240 located between the first frame 210 and the second frame 220. The spring portion 240 may be in the form of a plate spring. When swelling of the battery cell 110 occurs, the spring portion 240 inside the support frame 200 is compressed, thereby absorbing some of the swelling of the battery cell 110.

[0067] Meanwhile, there is no particular limitation on the method of connecting the first frame 210 and the second frame 220, but a physical connection method may be applied. For example, as shown in Fig. 7, the first frame 210 and the second frame 220 may be physically connected by a type of crimping connection method in which both ends of the second frame 220 are bent and wrap around both ends of the first frame 210.

[0068] The pressure member according to this embodiment will be described in detail below.

[0069] 10 and 11 are a perspective view and a side view, respectively, of a pressure member according to one embodiment of the present invention.

[0070] 2, 10 and 11, as described above, the pair of pressure members 1200 according to this embodiment are disposed in the pack case 1100, and the battery module 100 is positioned between the pair of pressure members 1200.

[0071] The pressing member 1200 according to this embodiment may be an elastic member that applies a pressing force toward the battery module 100. For example, the pressing member 1200 may have a spring structure that applies a pressing force in the direction in which the battery module 100 is positioned. As a result, when the battery module 100 is forcibly inserted between the pair of pressing members 1200, a pressing force may be applied to both sides of the battery module 100.

[0072] More specifically, the pressing members 1200 may have a leaf spring structure that protrudes in the direction in which the battery module 100 is positioned. In addition, the distance between the pair of pressing members 1200 may be equal to or slightly smaller than the width of the battery module 100. Here, the width of the battery module 100 may refer to the length of the battery module 100 along the stacking direction of the battery cells 110 (the direction parallel to the x-axis).

[0073] A pair of pressure members 1200 having the above-described structure is provided in the pack case 1100, and the battery module 100 is inserted between them in an interference fit, with pressure being applied to the battery module 100 by the pair of pressure members 1200. Here, "inserted by an interference fit" refers to a form in which the battery module 100 is forcibly inserted between the pair of pressure members 1200, with the gap between the pair of pressure members 1200 being equal to or slightly narrower than the width of the battery module 100. That is, the gap between the pair of pressure members 1200 is equal to or narrower than the width of the battery module 100, and the battery module 100 is forcibly inserted between the pair of pressure members 1200. As a result, pressure is naturally applied to the battery module 100 by the pair of pressure members 1200. In other words, the battery module 100 can be fitted between the pair of pressure members 1200 in a resiliently assembled form. Elastic assembly refers to a form in which the battery module 100 is fitted between a pair of pressure members 1200, causing the pair of pressure members 1200 to behave elastically due to the battery module 100, and the battery module 100 is fixed in place by the elastic force of the pair of pressure members 1200, and is also subjected to pressure.

[0074] More specifically, the pressing member 1200 may be configured to bend and protrude from both ends of the pressing member 1200 toward the location of the battery module 100 in a direction (y-axis direction or -y-axis direction) parallel to the direction in which the electrode leads 150 of the battery cells 110 protrude, such that the center of the pressing member 1200 is bent toward the location of the battery module 100. This allows the pressing member 1200 to apply a certain level of pressure to both sides of the battery module 100.

[0075] In particular, as described above, the battery cells 110 may be stacked in one direction within the battery module 100. As shown in FIGS. 2 and 4, a plurality of battery cells 110 may be stacked in a direction parallel to the x-axis to form the battery cell stack 120. In this embodiment, the one direction in which the battery cells 110 are stacked may be parallel to one surface of the bottom 1100F of the pack case 1100. The battery cells 110 may be stacked such that one surface of the battery cells 110, specifically one surface of the battery body 113 (see FIG. 5) of each battery cell 110, is perpendicular to one surface of the bottom 1100F of the pack case 1100. In other embodiments of the present invention, the battery cells 110 may be stacked in a different manner, which will be described again with reference to FIG. 14.

[0076] In this case, the pair of pressure members 1200 may be positioned on both sides of the battery module 100 in the direction in which the battery cells 110 are stacked. The pair of pressure members 1200 may pressurize both sides of the battery module 100 in the direction in which the battery cells 110 are stacked. That is, the pair of pressure members 1200 apply pressure in a direction that can control the swelling of the battery cells 110.

[0077] 10 and 11, the pressing member 1200 according to this embodiment may have a configuration in which a plurality of spring members 1210 are arranged at intervals along the height direction. Individual spring members 1210, each having a curved center, are arranged at regular intervals along the height direction where the battery module 100 is located. Here, the height direction refers to a direction perpendicular to one surface of the bottom 1100F of the pack case 1100 and parallel to the z-axis direction.

[0078] The pressure member 1200 may further include connecting parts 1220 that connect the spring members 1210 so that the spring members 1210 are maintained at regular intervals. There is no particular limitation on the number or location of the connecting parts 1220, but they may be located at both ends of the pressure member 1200. Furthermore, other connecting parts 1220 may be additionally provided at regular intervals between the connecting parts 1220 located at both ends.

[0079] As described above, the pressure member 1200 is not configured as a single leaf spring, but includes individual spring members 1210 that are separated from each other, allowing for individual responses to the swelling characteristics of each position of the battery cell 110. That is, in this embodiment, the individual spring members 1210 are separated, which has the advantage of exhibiting flexible elastic behavior in response to swelling of the battery cell 110 compared to a completely integrated structure.

[0080] The material of the pressure member 1200 according to this embodiment will be described in detail below. The pressure member 1200 according to this embodiment may include a composite material, which may be fiber reinforced plastic (FRP) or carbon fiber reinforced plastic (CFRP). The fiber reinforced plastic and carbon fiber reinforced plastic are plastic composite materials reinforced with glass fiber and carbon fiber, respectively, and are materials with excellent mechanical properties and corrosion resistance.

[0081] When a metal material is used for the pressure member 1200, there is a problem in that the amount of displacement that can be absorbed when swelling the battery cells 110 is small due to a low tensile modulus of elasticity. Even if the battery cell stack 120 is only slightly displaced due to swelling of the battery cells 110, a large amount of stress is generated in the curved portion of the leaf spring. In the case of battery cells that swell to a large extent, such as pure silicon cells, all-solid-state batteries, and high SiO content cells, the amount of displacement that must be absorbed by the battery module is also large due to the large degree of swelling. Therefore, frames made of metal in battery modules that use these battery cells have limitations in absorbing swelling.

[0082] On the other hand, fiber reinforced plastics and carbon fiber reinforced plastics have tensile strengths equal to or greater than those of metals and a lower Young's modulus than metals, so they have high rigidity against swelling of the battery cell and can exhibit elastic behavior that can effectively absorb swelling. Pure Si cells and all-solid-state batteries generate pressures of up to 3 to 8 MPa at the end of life (EOL), but composite materials of fiber reinforced plastics and carbon fiber reinforced plastics can exhibit elastic behavior even at such high pressures, making them suitable for use in the pressing member 1200 of this embodiment.

[0083] In addition, fiber reinforced plastics and carbon fiber reinforced plastics are manufactured by laminating glass fibers or carbon fibers and then hardening resin around them, which has the advantage that the strength and elastic modulus can be set differently in each direction.

[0084] However, conventional composite materials such as fiber reinforced plastics and carbon fiber reinforced plastics were developed with an emphasis on lightweight and high strength properties, and have the drawback of being brittle and relatively expensive. Therefore, the composite material of this embodiment solves these problems by changing the resin material and incorporating a sheet material in addition to the fiber material.

[0085] 2, 3, 6, and 10, the support frame 200 according to this embodiment may have a recessed shape corresponding to the protruding shape of the pressure member 1200. Specifically, one surface of the support frame 200 facing the pressure member 1200 may have a recessed shape, and the other surface facing the battery cell stack 120 may have a flat shape. More specifically, the second frame 220 of the support frame 200 faces the pressure member 1200, and one surface of the second frame 220 may have a recessed shape corresponding to the protruding shape of the pressure member 1200. Meanwhile, the first frame 210 of the support frame 200 faces the battery cell stack 120, and the first frame 210 may have a flat shape.

[0086] As a result, when the battery module 100 is inserted between the pair of pressure members 1200 in an interference fit, the pressure members 1200 can apply a predetermined pressure while being in close contact with both side surfaces of the battery module 100 .

[0087] The interference fit of the battery module according to this embodiment will be described in detail below with reference to FIG. 12 and other figures.

[0088] 12 is a plan view showing the arrangement of a battery cell stack, a support frame, and a pressure member according to one embodiment of the present invention. Specifically, it is a plan view of the portion of the battery pack shown in FIG. 2 where the support frame 200 of the battery module 100 and the pressure member 1200 come into contact, as viewed along the -z axis direction on the xy plane.

[0089] 2, 7, and 12, when the battery module 100 is inserted between the pair of pressing members 1200, the rotation of the at least one bearing ball 230 allows the battery module 100 to be tightly coupled between the pair of pressing members 1200. That is, the at least one bearing ball 230 facilitates the process of coupling the battery module 100 between the pair of pressing members 1200 with a tight fit.

[0090] In some cases, a certain level of pressure needs to be applied to the battery module 100 in order for the battery to perform well. For example, the battery cell 110 according to this embodiment may be an all-solid-state battery. In the case of an all-solid-state battery, a high pressure of at least 1 to 5 MPa needs to be applied in order for the battery to perform well. The conventional battery module 10 shown in FIG. 1 has structural difficulties in applying such a high level of pressure.

[0091] In order to apply such a high level of pressure, it is necessary to provide pressure members 1200 with a predetermined elasticity and insert the battery module 100 between them in an interference fit manner. Accordingly, in this embodiment, the spacing between the pressure members 1200, which have a leaf spring structure protruding in opposite directions, is adjusted and the battery module 100 is forcibly inserted between them, so that high pressure is naturally applied to the battery module 100 as soon as the battery module 100 is inserted.

[0092] As described above, in order to apply pressure to the battery cells 110, the pair of pressure members 1200 are preferably positioned on both side surfaces of the battery module 100 in the direction in which the battery cells 110 are stacked. That is, the pair of pressure members 1200 can apply pressure to both side surfaces of the battery module 100 in the direction in which the battery cells 110 are stacked.

[0093] Furthermore, in order to improve the assembly efficiency of this interference fit insertion method, in this embodiment, bearing balls 230 are provided on the frame 200 located on the side of the battery module 100.

[0094] As described above, the bearing balls 230 are partially exposed and protrude in the direction of the pressure member 1200 so as to come into contact with the pressure member 1200. Since the bearing balls 230 rotate during the insertion of the battery module 100, the interference fit of the battery module 100 can be facilitated. In some cases, hydraulic pressure can be applied to the battery module 100 to facilitate smooth insertion of the battery module 100. There is no particular limitation on the number or position of the bearing balls 230 formed on the support frame 200 as long as it is possible to improve the ease of assembly of the interference fit.

[0095] The battery pack 1000 according to this embodiment is intended to achieve a high pressure level of 1 to 5 MPa by the tight fit method of the battery module 100 as described above.

[0096] Meanwhile, even high levels of swelling or 10 to 20% bleeding of the battery cells 110 can be effectively absorbed through the pressure members 1200 located on the sides of the battery module 100. Although not specifically shown, a compression pad is additionally disposed inside the battery module 100 to absorb swelling and bleeding.

[0097] 2 and 3, the pair of pressure members 1200 are disposed upright and perpendicular to one surface of the bottom 1100F of the pack case 1100. The battery pack 1000 according to this embodiment may further include at least two vertical beams 1300 disposed on the pack case 1100. The at least two vertical beams 1300 are disposed perpendicular to one surface of the bottom 1100F of the pack case 1100, and the pair of pressure members 1200 and the battery module 100 may be located between adjacent pairs of the at least two vertical beams 1300. The pressure members 1200 may be coupled and fixed to the pack case 1100. There are no particular limitations on the method of coupling the pressure members 1200 to the pack case 1100, and a mechanical fastening method, an adhesive member, or the like may be used. For example, both ends of the pressure member 1200 may be fixed to the pair of vertical beams 1300, respectively.

[0098] Meanwhile, mounting holes 200MH may be formed in the support frame 200. The mounting holes 200MH are formed to penetrate in the height direction, and the battery modules 100 may be mounted and fixed to the pack case 1100 using the mounting holes 200MH. For example, the battery modules 100 may be mounted and fixed to the pack case 1100 in such a manner that bolts pass through the mounting holes 200MH and are coupled to the bottom 1100F of the pack case 1100.

[0099] 3, the battery module 100 according to this embodiment may include a module frame that houses the battery cells 110, and the support frame 200 may form both sides of the module frame. That is, instead of a separate frame being provided, the support frame 200 itself may form both sides of the module frame that houses the battery cells 110. Although the top and bottom of the battery cell stack 120 are shown in FIG. 3 as being open, the module frame may be formed by further providing cover members that cover the top and bottom, if necessary.

[0100] FIG. 13 is an exploded perspective view showing a battery module according to another embodiment of the present invention.

[0101] 13, a battery module according to another embodiment of the present invention may include a battery cell stack 120 in which battery cells 110 are stacked, a module frame 400 that houses the battery cell stack 120, and support frames 200 attached to both sides of the module frame 400. The module frame 400 may be open on one side and the other, and end plates 300 may be located on the open sides of the module frame 400. The support frame 200 has the same configuration as described above, but unlike the battery module of FIG. 3, it is attached to the module frame 400. That is, a battery module 100 may be manufactured by providing a separate module frame 400 that houses the battery cell stack 120, and attaching support frames 200 to both sides of the module frame 400.

[0102] FIG. 14 is a perspective view showing a battery pack according to another embodiment of the present invention, in which the stacking direction of the battery cells is changed.

[0103] 14, a battery pack 1000a according to another embodiment of the present invention includes a battery module 100 including a plurality of battery cells 110, a pack case 1100 that houses the battery module 100, and a pair of pressing members 1200 that are disposed in the pack case 1100, with the battery module 100 positioned between the pair of pressing members 1200. The battery module 100 is inserted between the pair of pressing members 1200 in an interference fit, and a pressing force is applied to the battery module 100 by the pair of pressing members 1200.

[0104] The battery cells 110 may be stacked in one direction, and the one direction in which the battery cells 110 are stacked may be perpendicular to one surface of the bottom 1100F of the pack case 1100. The battery cells 110 may be stacked in a state in which one surface of the battery cells 110, specifically one surface of the battery body 113 (see FIG. 5 ) of the battery cell 110, is parallel to one surface of the bottom 1100F of the pack case 1100.

[0105] As a result, the pair of pressure members 1200 can be arranged alongside one surface of the bottom 1100F of the pack case 1100. The pair of pressure members 1200 can also be positioned spaced apart from each other along the height direction on the bottom 1100F of the pack case 1100. The pair of pressure members 1200 can also be positioned between at least two vertical beams 1300 arranged on the pack case 1100.

[0106] Meanwhile, the battery module 100 may include a support frame 200 facing a pair of pressure members 1200, and as shown in the drawing, the support frame 200 may be formed on both the upper and lower surfaces of the battery module 100 depending on the stacking direction of the battery cells 110. At least one bearing ball 230 described above may be inserted into such a frame 200, and a portion of the bearing ball 230 is exposed and protrudes from one surface of the support frame 200 toward the pressure member 1200.

[0107] Hereinafter, a battery pack according to a modified embodiment of the present invention will be described in detail with reference to FIGS.

[0108] Fig. 15 is a perspective view showing a battery pack according to a modified embodiment of the present invention, and Fig. 16 is a plan view showing a pressing member included in the battery pack of Fig. 15 as seen from above.

[0109] 15 and 16, a battery pack 1000b according to a modified embodiment of the present invention includes a battery module 100 including a plurality of battery cells 110, a pack case 1100 that houses the battery module 100, and a pair of pressing members 1400 that are disposed in the pack case 1100, with the battery module 100 being positioned between the pair of pressing members 1400. The battery module 100 is inserted between the pair of pressing members 1400 in an interference fit, and a pressing force is applied to the battery module 100 by the pair of pressing members 1400.

[0110] The pair of pressure members 1400 may be elastic bodies that apply pressure toward the battery module 100, and at least one bearing ball 1430 may be inserted into the pair of pressure members 1400, and the at least one bearing ball 1430 may rotate within the pressure members 1400. In addition, the pair of pressure members 1400 may be fixed to the pack case 1100 between a pair of adjacent vertical beams 1300. That is, unlike the battery pack 1000 described above, the battery pack 1000b according to this embodiment has at least one bearing ball 1430 provided inside the pair of pressure members 1400 fixed to the pack case 1100.

[0111] Specifically, the pressure member 1400 may include a first pressure frame 1410, a second pressure frame 1420, and a bearing ball 1430 positioned between the first pressure frame 1410 and the second pressure frame 1420. The first pressure frame 1410 and the second pressure frame 1420 may be plate-shaped members. One side of the first pressure frame 1410 and one side of the second pressure frame 1420 may be spaced apart from each other by a predetermined distance, and the bearing ball 1430 may be positioned therebetween.

[0112] At least one bearing ball 1430 positioned inside the pressure member 1400 may be rotatably disposed within the pressure member 1400. A portion of the at least one bearing ball 1430 is exposed and protrudes from one side of the pressure member 1400 toward the battery module 100. The exposed portion of the bearing ball 1430 may contact the battery module 100. As an example, side plates 410, 420 may be provided on both sides of the battery module 100 in the direction in which the battery cells 110 are stacked. The side plates 410, 420 may be plate-shaped members, and the exposed portion of the bearing ball 1430 may contact the side plates 410, 420 of the battery module 100.

[0113] When the battery module 100 is inserted between the pair of pressing members 1400 with an interference fit, the rotation of at least one bearing ball 1430 facilitates the interference fit. Meanwhile, the pressing member 1400 may further include a spring portion 1440 positioned between the first pressing frame 1410 and the second pressing frame 1420. The spring portion 1440 may be in the form of a leaf spring. When the battery module 100 is inserted between the pair of pressing members 1400, the spring portion 1440 is compressed, thereby achieving an interference fit of the battery module 100.

[0114] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are used for convenience of explanation and may change depending on the position of the target object, the position of the observer, etc.

[0115] The battery pack according to the present embodiment may include various control and protection systems such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system in addition to the battery modules.

[0116] The battery pack can be applied to various devices, specifically, transportation means such as electric bicycles, electric cars, and hybrids, and energy storage systems (ESS), but is not limited thereto, and can be applied to various devices that can use secondary batteries.

[0117] 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 following claims also fall within the scope of the present invention. [Explanation of symbols]

[0118] 100 Battery Module 110 battery cells 200 support frame 1000 battery packs 1100 pack case 1200 Pressure member

Claims

1. a battery module including a plurality of battery cells; A pack case that houses the battery module; and a pair of pressure members disposed in the pack case; the battery module is positioned between the pair of pressure members, the battery module is configured such that a pressure is applied to the battery module by the pair of pressure members, the pressing member is configured to protrude in a direction in which the battery module is positioned, The battery pack is characterized in that the pressure member includes a plurality of spring members spaced apart along the height direction, and a connecting portion that connects each of the plurality of spring members so that each of the plurality of spring members is maintained at a constant interval.

2. The battery pack according to claim 1 , wherein the pressure member applies a pressure force toward the battery module.

3. 2. The battery pack according to claim 1, wherein the gap between the pair of pressure members is configured to be equal to or narrower than the width of the battery module.

4. The battery cells are stacked in one direction in the battery module, The battery pack according to claim 1 , wherein the pair of pressure members are located on both sides of the battery module in the direction in which the battery cells are stacked.

5. The battery pack according to claim 4 , wherein the one direction in which the battery cells are stacked is parallel to one surface of the bottom of the pack case.

6. The battery pack according to claim 1 , wherein the battery module includes a support frame facing the pair of pressure members.

7. The battery pack according to claim 6, wherein the support frame has a recessed shape corresponding to the protruding shape of the pressing member.

8. The battery pack according to claim 6 , wherein one surface of the support frame facing the pressing member is a recessed surface, and the other surface facing the battery cell is flat.

9. At least one bearing ball is inserted into the support frame; 7. The battery pack according to claim 6, wherein at least one of the bearing balls rotates within the support frame.

10. 10. The battery pack of claim 9, wherein a portion of at least one of the bearing balls is exposed and protrudes from one surface of the support frame toward the pressure member, and the at least one bearing ball contacts the pressure member.

11. the battery module includes a module frame that houses the battery cells; 7. The battery pack according to claim 6, wherein the support frame forms both side surfaces of the module frame.

12. the battery module includes a module frame that houses the battery cells; The battery pack according to claim 6, wherein the support frame is attached to both side surfaces of the module frame.

13. further comprising at least two vertical beams disposed on the pack case; 2. The battery pack according to claim 1, wherein the pair of pressure members and the battery module are located between a pair of adjacent vertical beams among the at least two vertical beams.

14. The battery pack according to claim 1 , wherein the battery cells are all-solid-state batteries.

15. A device comprising the battery pack of claim 1.

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