Battery packs and devices containing them

Abstract

A battery pack according to one embodiment of the present invention includes a plurality of battery cell assemblies, each comprising a battery cell stack formed by stacking a plurality of battery cells, the sides and top and bottom surfaces of the battery cell stack being exposed to the outside; a lower pack frame on which the plurality of battery cell assemblies are mounted; and a cross beam formed inside the lower pack frame and extending along between an adjacent pair of battery cell assemblies, wherein each battery cell assembly includes a sub-cross beam in contact with at least one side of the battery cell stack, and the cross beam and the sub-cross beam are spaced apart from each other.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2023 - 0105715 filed on August 11, 2023, and Korean Patent Application No. 10 - 2024 - 0106318 filed on August 8, 2024, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a battery pack and a device including the same, and more specifically, to a battery cell assembly including a battery cell stack in which a plurality of battery cells are stacked, a battery pack having a CTP (Cell To Pack) structure for accommodating the battery cell assembly inside a pack frame, and a device including the same.

[0003] Particularly, the present invention relates to a battery pack including a sub - cross beam located on at least one side surface of the battery cell stack, and the sub - cross beam is spaced apart from a cross beam inside the pack frame, and a device including the same.

Background Art

[0004] In recent years, the demand for portable electronic products such as notebook computers, video cameras, mobile phones, etc. has increased rapidly, and as the development of electric vehicles, energy storage batteries, robots, satellites, etc. has become full - scale, research on high - performance secondary batteries capable of repeated charging and discharging has been actively conducted.

[0005] Currently, commercially available secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, lithium secondary batteries, etc. Among these, lithium secondary batteries have attracted attention because they have almost no memory effect compared to nickel - based secondary batteries, can be freely charged and discharged, have a very low self - discharge rate, and have a high energy density.

[0006] Such lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive electrode active material and negative electrode active material, respectively. Furthermore, the lithium secondary battery comprises a positive electrode plate and a negative electrode plate coated with these positive and negative electrode active materials, an electrode assembly in which the positive and negative electrode plates are arranged with a separator in between, and an outer casing that seals and houses the electrode assembly together with the electrolyte.

[0007] On the other hand, lithium secondary batteries can be classified into two types based on the shape of the battery case: can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in an aluminum laminate sheet pouch. Can-type secondary batteries can be further classified into cylindrical batteries and prismatic batteries depending on the shape of the metal can.

[0008] Here, the pouch of a pouch-type secondary battery can be broadly divided into a lower sheet and an upper sheet that covers it. At this time, an electrode assembly formed by stacking and winding a positive electrode, a negative electrode, and a separator is housed in the pouch. After housing the electrode assembly, the edges of the upper and lower sheets are sealed by heat fusion or the like. In addition, electrode tabs drawn out from each electrode are connected to electrode leads, and an insulating film can be added to the part of the electrode lead that comes into contact with the sealing part.

[0009] Thus, pouch-type rechargeable batteries offer the flexibility to be configured in a variety of forms. Furthermore, pouch-type rechargeable batteries have the advantage of achieving the same capacity with a smaller volume and mass.

[0010] Such lithium secondary batteries are used in battery modules and battery packs that are electrically connected after being made into a dense structure by stacking or arranging multiple battery cells, either on their own or mounted in cartridges, in order to provide high voltage and high current.

[0011] However, conventional battery packs can be disadvantageous in terms of energy density. Typically, in the process of modularizing a large number of battery cells by housing them inside a module case, the volume of the battery pack may unnecessarily increase due to various components such as the module case or stacking frame, while the space occupied by the battery cells decreases. Furthermore, the space occupied by the components themselves, such as the module case and stacking frame, as well as the space required to ensure assembly tolerances for these components, can reduce the space available for housing the battery cells. Therefore, there are limitations to increasing the energy density of conventional battery packs.

[0012] Furthermore, conventional battery packs can be disadvantageous from an assembly standpoint. In particular, manufacturing a battery pack involves first modularizing numerous battery cells to form battery modules, and then housing these battery modules in a pack case, which complicates the manufacturing process. Moreover, the process and structure for forming the cell stack using the aforementioned stacking frame, bolts, plates, etc., can become extremely complex.

[0013] Furthermore, with conventional battery packs, the module case is housed inside the pack case, and the battery cells are housed inside the module case, which presents a challenge in ensuring excellent cooling. In particular, when heat from the battery cells housed inside the module case is dissipated to the outside of the pack case via the module case, cooling efficiency decreases, and the cooling structure can become complex.

[0014] In particular, battery packs must control the swelling development of battery cells that occurs during the charging and discharging process of the battery cells contained within the battery module. More specifically, during repeated charging and discharging, the internal electrolyte of the battery cells decomposes, generating gas and causing the battery cells to swell, i.e., undergo swelling development. If such swelling of battery cells cannot be controlled, it can cause structural deformation of the battery module containing a large number of battery cells and adversely affect the durability and performance of the battery module.

[0015] In particular, recently, to manufacture high-capacity battery packs, pure Si cells and high-SiO content cells are used as battery cells, but in the case of these cells, the degree of swelling is greater. In other words, in order to manufacture high-capacity battery modules and battery packs, it is essential to effectively control the swelling of the battery cells inside the battery modules and battery packs.

[0016] Therefore, there is currently a need for technological development of battery packs that can effectively control battery cell swelling while improving spatial efficiency. [Overview of the project] [Problems that the invention aims to solve]

[0017] The problem that the present invention aims to solve is to provide a battery cell assembly including a battery cell stack in which multiple battery cells are stacked, a battery pack with a CTP (Cell To Pack) structure that houses the assembly inside a pack frame, and a device including the same.

[0018] In particular, the present invention provides a battery pack and a device including it, which includes a sub-crossbeam located on at least one side of the battery cell stack, wherein the sub-crossbeam is spaced apart from the crossbeam inside the pack frame.

[0019] The problems that this invention aims to solve are not limited to those described above, and any problems not mentioned will be clearly understood by a person with ordinary skill in the art as described herein and in the accompanying drawings. [Means for solving the problem]

[0020] A battery pack according to one embodiment of the present invention includes a battery cell stack formed by stacking a plurality of battery cells, the battery cell stack having both sides and top and bottom surfaces exposed to the outside, a plurality of battery cell assemblies; a lower pack frame on which the plurality of battery cell assemblies are mounted; and a cross beam formed inside the lower pack frame and extending along between an adjacent pair of battery cell assemblies, the battery cell assembly includes a sub-cross beam in contact with at least one side of the battery cell stack, and the cross beam and the sub-cross beam are spaced apart from each other.

[0021] The battery cell assembly further includes a busbar frame located on the front and rear surfaces of the battery cell stack, and at least one first coupling hole is formed at both ends of the subcrossbeam in the portion overlapping with the busbar frame, and the subcrossbeam and the busbar frame can be fixed together via the first coupling hole.

[0022] The subcrossbeam and the busbar frame may be bolted together.

[0023] The sub-crossbeam includes a main body and a bent portion, the main body extending along the side surface of the battery cell stack, one end of the bent portion connected to the upper end of the main body, and the other end of the bent portion may extend toward the upper part of the crossbeam.

[0024] The other end of the bent portion may overlap with the upper part of the crossbeam.

[0025] At least one second coupling hole is formed in a portion of the other end of the bent portion that overlaps with the upper part of the cross beam, and the other end of the bent portion and the upper part of the cross beam can be fixed through the second coupling hole.

[0026] The other end of the bent portion and the upper part of the cross beam may be bolted to each other.

[0027] The height of the cross beam may be smaller than the height of the lower pack frame.

[0028] The sum of the height of the cross beam and the thickness of the bent portion may be the same as or smaller than the height of the lower pack frame.

[0029] The sub-cross beam includes a first sub-cross beam and a second sub-cross beam. The first sub-cross beam can be in contact with one side surface of the battery cell laminate, and the second sub-cross beam can be in contact with the other side surface of the battery cell laminate.

[0030] The battery cell assembly further includes a first thermal resin layer applied between the lower surface of the battery cell laminate and the lower pack frame, and the first thermal resin layer may extend to the lower part of the sub-cross beam.

[0031] The battery cell assembly includes a second thermal resin layer applied to the upper part of the battery cell laminate, and the second thermal resin layer may extend to the upper part of the sub-cross beam.

[0032] The battery cell assembly may further include a pad member located between the battery cell laminate and the sub-cross beam.

[0033] The device according to another embodiment of the present invention includes at least one of the above-described battery packs.

Advantages of the Invention

[0034] According to the embodiments, the battery pack and device containing the same of the present invention have the advantages of a battery cell assembly including a battery cell stack in which a plurality of battery cells are stacked, and a CTP (Cell To Pack) structure that houses the assembly inside a pack frame, and have a higher energy density and a simplified assembly process compared to conventional battery packs.

[0035] Furthermore, the battery pack and device containing the same of the present invention include a subcross beam located on at least one side of the battery cell stack, which improves the fixing force of the battery cell assembly to the pack frame and further improves the rigidity of the CTP structure battery pack.

[0036] In addition, the battery pack and device including the present invention have the aforementioned sub-crossbeams separated from the crossbeams inside the pack frame, which allows for effective control of the swelling development of the battery cells.

[0037] The effects of the present invention are not limited to those described above, and any effects not mentioned herein will be clearly understood by a person skilled in the art to which the present invention pertains, based on this specification and the accompanying drawings. [Brief explanation of the drawing]

[0038] [Figure 1] This is a perspective view of a battery cell assembly according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of the battery cell assembly. [Figure 3] This is a side view showing one of the battery cells included in the battery cell assembly shown in Figure 1. [Figure 4] Figure 1 is a perspective view showing a subcross beam located on at least one side of the battery cell assembly. [Figure 5] This is a perspective view showing a battery pack according to another embodiment of the present invention. [Figure 6]This is a schematic cross-sectional view showing a portion of the cross-section cut along the zy-plane in Figure 5. [Modes for carrying out the invention]

[0039] The following describes various embodiments of the present invention in detail, with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily implement them. The present invention can be realized in various different forms and is not limited to the embodiments described herein.

[0040] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals will be used throughout the specification for identical or similar components.

[0041] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for illustrative purposes, and the present invention is not necessarily limited to those shown. In the drawings, thicknesses are shown enlarged to clearly represent various layers and regions. Also, in the drawings, the thicknesses of some layers and regions are shown exaggerated for illustrative purposes.

[0042] Furthermore, when a specification states that a certain part "includes" a certain component, unless otherwise stated, this means that it may include other components rather than excluding them.

[0043] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0044] The following describes a battery cell assembly according to an embodiment of the present invention.

[0045] Figure 1 is a perspective view of a battery cell assembly according to one embodiment of the present invention. Figure 2 is an exploded perspective view of the battery cell assembly of Figure 1. Figure 3 is a side view showing one of the battery cells included in the battery cell assembly of Figure 1. Figure 4 is a perspective view showing a subcross beam located on at least one side of the battery cell assembly of Figure 1.

[0046] Referring to Figures 1 and 2, each battery cell assembly 100 includes a battery cell stack 120 formed by stacking multiple battery cells 110. More specifically, the battery cell stack 120 can be formed by stacking multiple battery cells 110 so that they are electrically connected to each other. Here, the number of battery cells 110 constituting the battery cell stack 120 can be adjusted depending on the circumstances.

[0047] Furthermore, both sides and the top and bottom surfaces of the battery cell stack 120 can be exposed to the outside. More specifically, unlike conventional battery modules which are modularized by housing them inside a separate module case, the battery cell assembly 110 does not house the battery cell stack 120 inside a separate module case, and is housed in the lower pack frame 1100 (Figure 5) with both sides and the top and bottom surfaces of the battery cell stack 120 exposed to the outside.

[0048] As a result, the battery cell assembly 100 according to this embodiment does not require additional components such as a module case, as is the case with conventional battery modules or packs. In other words, by eliminating the space occupied by these components in this embodiment, the battery cells can occupy even more space, thereby improving energy density, reducing overall volume and weight, and simplifying the manufacturing process.

[0049] Furthermore, in the battery cell assembly 100, the lower part of the battery cell stack 120 can be exposed to the outside. That is, when the battery cell assembly 100 is housed in the lower pack frame 1100 (Figure 5), which will be described later, the lower parts of the battery cells 110 included in the battery cell stack 120 can be exposed toward the bottom surface of the lower pack frame 1100 (Figure 5).

[0050] As a result, in this embodiment, the lower part of the battery cell 110 contained in the battery cell stack 120 can directly contact the bottom surface of the lower pack frame 1100 (Figure 5), thereby improving the cooling performance of the battery pack 1000 (Figure 5). In other words, the heat released from the battery cell 110 is directly transferred to the lower pack frame 1100 (Figure 5), further improving the cooling performance of the battery pack 1000 (Figure 5). In this case, a separate cooling structure does not need to be provided between the battery cell 110 and the lower pack frame 1100 (Figure 5), thus achieving efficient cooling performance.

[0051] Referring to Figures 2 and 3, in the battery cell assembly 100, the battery cell 110 may be a pouch-type battery cell. Such a pouch-type battery cell can be formed by housing an electrode assembly in a laminate sheet pouch case containing a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. Such a battery cell 110 can be formed in a rectangular sheet structure. Specifically, the battery cell 110 according to this embodiment has a structure in which two electrode leads 111 and 112 face each other and protrude from one end 114a and the other end 114b of the battery body 113, respectively. The battery cell 110 can be manufactured by housing an electrode assembly (not shown) in the battery case 114, and then bonding both ends 114a and 114b of the battery case 114 to a side portion 114c that connects them. In other words, the battery cell 110 according to one embodiment of the present invention has a total of three sealing parts, the sealing parts are sealed by methods such as fusion bonding, and the remaining other side can be made up of a connecting part 115.

[0052] However, the aforementioned battery cell 110 is an illustrative structure, and it is of course possible to have a unidirectional battery cell in which the two electrode leads protrude in the same direction.

[0053] Multiple such battery cells 110 are arranged in groups, and these multiple battery cells 110 are stacked so as to be electrically connected to each other to form a battery cell stack 120. In particular, as shown in Figure 2, multiple battery cells 110 can be stacked along a direction parallel to the y-axis. The battery case 114 usually consists of a laminate structure of a resin layer / metal thin film layer / resin layer. For example, if the surface of the battery case consists of an O(oriented)-nylon layer, when stacking a large number of battery cells to form a medium-to-large battery module, it tends to slip easily due to external impacts. Therefore, in order to prevent this and maintain a stable stacked structure of the battery cells, an adhesive member such as double-sided tape or a chemical adhesive that bonds through a chemical reaction during bonding can be attached to the surface of the battery case to form the battery cell stack 120.

[0054] As another example, unlike in Figure 3, the battery cell 110 may be a prismatic battery cell or a cylindrical battery cell in the form of a jelly roll. However, any configuration that allows for the formation of a battery cell stack 120 containing a large number of battery cells 110 within the limited space inside the battery cell assembly 100 is applicable to this embodiment.

[0055] On the other hand, the battery cell assembly 100 according to this embodiment may further include a first end plate 310 and a second end plate 320 located on one side and the other side of the battery cell stack 120, respectively; a first busbar frame 410 located between the battery cell stack 120 and the first end plate 310; and a second busbar frame 420 located between the battery cell stack 120 and the second end plate 320.

[0056] More specifically, the first busbar frame 410 and the first end plate 310 can be sequentially positioned on one side of the battery cell 110 in the direction (x-axis direction) from which one of the electrode leads 111 protrudes, and the second busbar frame 420 and the second end plate 320 can be sequentially positioned on the other side of the battery cell 110 in the direction (-x-axis direction) from which the other electrode lead 112 protrudes.

[0057] The first busbar frame 410 and the second busbar frame 420 can be arranged to cover the front and rear surfaces of the battery cell stack, respectively, corresponding to the directions in which the electrode leads 111 and 112 protrude (the x-axis direction and the -x-axis direction).

[0058] The first end plate 310 and the second end plate 320 can be positioned to cover one side of the first busbar frame 410 and one side of the second busbar frame 420, respectively. Such first end plates 310 and second end plates 320 may be plastic insulating covers with electrical insulation, protecting the busbars 500 and other electrical components such as electrode leads 111 and 112 located on the first busbar frame 410 and second busbar frame 420 from the outside, while simultaneously blocking the possibility of short circuits with the outside.

[0059] In other embodiments of the present invention, the first end plate 310 and the second end plate 320 can be made of a metal material such as aluminum and have high rigidity. However, in this case, it is preferable to add separate insulating covers between the first end plate 310 and the first busbar frame 410, and between the second end plate 320 and the second busbar frame 420.

[0060] The battery cell assembly 100 according to this embodiment may further include a busbar 500 mounted on a first busbar frame 410 and a second busbar frame 420. The second busbar frame 420 and the busbar 500 mounted thereon, although not shown in the figures, may have the same or similar structure as the first busbar frame 410.

[0061] The electrode leads 111 and 112 of the battery cell 110 can be bent and connected to the busbar 500 after passing through lead slits formed in the first busbar frame 410 or the second busbar frame 420. More specifically, one of the electrode leads 111 can be connected to the busbar 500 after passing through the lead slit in the first busbar frame 410, and the other electrode lead 112 can be connected to the busbar 500 after passing through the lead slit in the second busbar frame 420. There are no special restrictions on the method of connection between the electrode leads 111 and 112 and the busbar 500, but they can be welded together, for example.

[0062] In this manner, the battery cells 110 that make up the battery cell stack 120 can be connected to each other in series or in parallel.

[0063] On the other hand, although not specifically shown in the diagram, the first busbar frame 410 or the second busbar frame 420 may be fitted with terminal busbars for external power connection of the battery cell assembly 100 and module connectors for transmitting voltage and temperature sensing information.

[0064] Referring to Figures 2 and 4, the battery cell assembly 100 may include a subcrossbeam 200 that contacts at least one side of the battery cell stack 120. More specifically, the subcrossbeam 200 may include a first subcrossbeam 210 and a second subcrossbeam 220, where the first subcrossbeam 210 contacts one side of the battery cell stack 120 and the second subcrossbeam 220 contacts the other side of the battery cell stack 110. For example, the first subcrossbeam 210 and the second subcrossbeam 220 may be identical to each other but in a symmetrical configuration.

[0065] As an example, the subcrossbeam 200 can be made of steel, and more specifically, stainless steel (SUS). As another example, the cell cover can be made entirely of SUS material.

[0066] As a result, in the battery cell assembly 100 according to this embodiment, if the subcrossbeam 200 is made of steel, it has excellent mechanical strength and rigidity, so the stacked state of the multiple battery cells 110 included in the battery cell stack 120 can be supported more stably. In addition, in this case, damage or breakage of the battery cells 110 from external impacts, such as needle-shaped objects, can be prevented more effectively. Moreover, in this case, the handling of the battery cells 110 may become easier.

[0067] Referring to Figure 4, the subcrossbeam 200 may include a main body 201 and a bent portion 205. Here, the main body 201 and the bent portion 205 may be connected to each other. Here, the main body 201 and the bent portion 205 may be integrated with each other or fixed by a separate joining / connecting method such as welding.

[0068] More specifically, the main body portion 201 may extend along the side surface of the battery cell stack 120. Here, the main body portion 201 may be the same size as or larger than the side surface of the battery cell stack 120.

[0069] In the subcrossbeam 200, at least one first coupling hole 201h may be formed at both ends of the subcrossbeam 200. More specifically, at least one first coupling hole 201h may be formed at both ends of the main body portion 201 of the subcrossbeam 200. Here, at least one first coupling hole 201h may be formed in the portion where the main body portion 201 of the subcrossbeam 200 and the busbar frames 410, 420 overlap. That is, the subcrossbeam 200 and the busbar frames 410, 420 can be fixed together via the first coupling hole 201h.

[0070] As an example, the subcrossbeam 200 and the busbar frames 410 and 420 may be bolted together. Here, although not shown in Figures 2 and 4, the subcrossbeam 200 and the busbar frames 410 and 420 may be fastened together by inserting a long bolt member into the first connecting hole 201h.

[0071] In another embodiment of the present invention, the subcrossbeam 200 can be fixed to the end plates 310 and 320 via the first coupling hole 201h. In this case, the position of the first coupling hole 201h in the subcrossbeam 200 can be changed to the portion where the main body 201 and the end plates 310 and 320 overlap.

[0072] As a result, the battery cell assembly 100 according to this embodiment further includes a subcross beam 200 located on one side of the battery cell stack 120, which additionally ensures the rigidity of the battery cell assembly 100 and allows the battery cells 110 contained in the battery cell stack 120 to be protected from external impacts while maintaining a stable stacked state.

[0073] Furthermore, one end of the bent portion 205 is connected to the upper end of the main body portion 201, and the other end of the bent portion 205 may extend in the opposite direction to the direction toward the battery cell stack 120. More specifically, the other end of the bent portion 205 may extend toward the upper part of the cross beam 1200 (Figure 5) formed on the lower pack frame 1100, which will be described later. That is, the other end of the bent portion 205 may overlap with the upper part of the cross beam 1200 (Figure 5).

[0074] In the subcrossbeam 200, at least one second bonding hole 205h may be formed in the bent portion 205. More specifically, at least one second bonding hole 205h may be formed at the other end of the bent portion 205. Here, at least one second bonding hole 205h may be formed in the portion where the other end of the bent portion 205 and the upper part of the crossbeam 1200 (Figure 5) overlap. That is, the other end of the bent portion 205 and the upper part of the crossbeam 1200 (Figure 5) can be fixed together via the second bonding hole 205h.

[0075] For example, the other end of the bent portion 205 and the upper part of the crossbeam 1200 (Figure 5) may be bolted together. Here, although not shown in Figures 2 and 4, a long bolt member may be inserted into the second connecting hole 205h to fasten the other end of the bent portion 205 and the upper part of the crossbeam 1200 (Figure 5) together.

[0076] As a result, the battery cell assembly 100 according to this embodiment further includes a subcross beam 200 located on one side of the battery cell stack 120, which additionally ensures the rigidity of the battery cell assembly 100 and allows the battery cells 110 contained in the battery cell stack 120 to be protected from external impacts while maintaining a stable stacked state.

[0077] In addition, in this embodiment, the battery cell assembly 100 has a sub-crossbeam 200 located on one side of the battery cell stack 120, and the crossbeam 1200 (Figure 5) is fixed to each other, so that the fixing force between the battery cell assembly 100 and the lower pack frame 1100 (Figure 5) can be effectively secured.

[0078] Furthermore, by fixing the sub-crossbeam 200 and the crossbeam 1200 (Figure 5) in this manner, a separate adhesive layer may be omitted on the lower part of the battery cell assembly 100, or even if an adhesive layer is added, a material with relatively weak adhesive strength may be used. In other words, if the adhesive layer between the lower part of the battery cell assembly 100 and the lower frame 1100 (Figure 5) is omitted, or if an adhesive layer with weak adhesive strength is added, the connection between the battery cell assembly 100 and the lower pack frame 1100 (Figure 5) can be easily released, and the replacement of the battery cell assembly 100 becomes easier.

[0079] Furthermore, the battery cell assembly 100 may further include a pad member 150 located between the battery cell stack 120 and the subcross beam 200. More specifically, the pad member 150 may be an insulating member, a heat insulating member, or a compression pad.

[0080] For example, if the pad member 150 is an insulating material, it can interrupt the electrical connection between the side surface of the battery cell stack 120 and external elements. As another example, if the pad member 150 is a heat insulating material, it can prevent heat from being transferred internally and externally when an abnormal phenomenon such as thermal runaway occurs in some of the battery cells 110 included in the battery cell stack 120. As yet another example, if the pad member 150 is a compression pad, it can effectively control swelling that occurs in some of the battery cells 110 included in the battery cell stack 120.

[0081] Furthermore, the battery cell assembly 100 according to this embodiment may further include connecting members 600 located on the upper and lower sides of the battery cell stack 120, respectively, and connecting the first sub-crossbeam 210 and the second sub-crossbeam 220. That is, the battery cell assembly 100 may have a configuration in which the battery cell stack 120 is not housed and sealed in a module housing, but rather the first sub-crossbeam 210 and the second sub-crossbeam 220 are arranged on both sides of the battery cell stack 120, and the first sub-crossbeam 210 and the second sub-crossbeam 220 are fixed via the connecting members 600. In other words, the battery cell assembly 100 according to this embodiment has a simplified module housing structure compared to the conventional one, and can be directly mounted on the battery pack 1000 (Figure 5) without a sealed module housing.

[0082] As a result, the battery cell assembly 100 according to this embodiment can omit the module housing structure and improve space utilization in units of the battery pack 1000 (Figure 5), which will be described later, thereby improving overall energy density and reducing weight.

[0083] The connecting member 600 in this embodiment may be a metal band. More specifically, the connecting member 600 may be a band containing an elastic metal material.

[0084] Multiple or individual connecting members 600 may be provided at least one location on either the upper or lower side of the battery cell stack 120. For example, multiple connecting members 600 may be provided at least one location on either the upper or lower side of the battery cell stack 120. Figure 2 shows that multiple connecting members 600 are provided on both the upper and lower sides of the battery cell stack 120. Such connecting members 600 can be spaced apart from each other at regular intervals and positioned on both the upper and lower sides of the battery cell stack 120. For example, Figure 2 shows that three connecting members 600 are arranged on both the upper and lower sides of the battery cell stack 120.

[0085] As described above, the connecting member 600 is a member that connects the first sub-crossbeam 210 and the second sub-crossbeam 220 to each other, and therefore may be configured to connect them in the direction from the first sub-crossbeam 210 to the second sub-crossbeam 220, that is, along the stacking direction of the battery cells 110. In other words, the connecting member 600 extends in a direction parallel to the y-axis direction, with one end connected to the first sub-crossbeam 210 and the other end connected to the second sub-crossbeam 220. Such a connecting member 600 can be fixed to the first sub-crossbeam 210 and the second sub-crossbeam 220 by welding.

[0086] Although not specifically shown in the figures, in another embodiment of the present invention, the connecting member 600 may further include long bolt members that fasten both ends of the connecting member 600 to the first sub-cross beam 210 and the second sub-cross beam 220. That is, the connecting member 600 can be fastened to the first sub-cross beam 210 and the second sub-cross beam 220 by bolt connection rather than welding.

[0087] As a result, in the battery cell assembly 100 according to this embodiment, the first sub-crossbeam 210 and the second sub-crossbeam 220 are also connected to each other by the connecting member 600, which further ensures the rigidity of the battery cell assembly 100 and allows for a more stable connection between the battery cell stack 120 and the sub-crossbeam 200.

[0088] On the other hand, referring again to Figure 2, the battery cell assembly 100 according to this embodiment may further include an insulating sheet 800 located between the battery cell stack 120 and the connecting member 600 located above the battery cell stack 120. The insulating sheet 800 is a thin, electrically insulating sheet and can be positioned to cover the entire upper surface of the battery cell stack 120 in order to ensure electrical insulation from the upper side of the battery cell stack 120. Such an insulating sheet 800 may be an insulating film or insulating tape, and its thickness may be 0.1 mm or less.

[0089] Figure 5 is a perspective view showing a battery pack according to another embodiment of the present invention. Figure 6 is a schematic cross-sectional view showing a portion of the cross-section cut along the zy-plane of Figure 5.

[0090] Referring to Figures 5 and 6, a battery pack 1000 according to one embodiment of the present invention may include a lower pack frame 1100 on which a plurality of battery cell assemblies 100 are mounted, and a crossbeam 1200 formed inside the lower pack frame 1100 and extending along between adjacent pairs of battery cell assemblies 100. Here, the crossbeam 1200 may be fixed to the bottom surface 1100F of the lower pack frame 1100 by a joining method such as welding, or they may be integrated with each other.

[0091] The battery pack 1000 may further include an upper pack frame (not shown) located on top of the battery cell assembly 100, although this is not shown in Figure 5. Here, the lower pack frame 1100 and the upper pack frame (not shown) are joined together by welding or adhesive or other means at their contact surfaces, thereby sealing the inside of the battery pack 1000. However, the pack frame of the battery pack 1000 may also include an upper pack frame with an open lower end and a lower pack frame that covers the lower part of the upper pack frame. For example, the lower pack frame 1100 and the upper pack frame (not shown) may be made of plastic or metal. In addition, the pack case may employ various battery pack exterior material materials known at the time of filing of the present invention.

[0092] Referring to Figures 5 and 6, the sub-crossbeam 200 and crossbeam 1200 included in the battery cell assembly 100 may be separated from each other. More specifically, the sub-crossbeam 200 and crossbeam 1200 of the battery cell assembly 100 may be separated from each other by a predetermined gap (G).

[0093] As a result, in the battery pack 1000 according to this embodiment, the battery cell assembly 100 is separated from the lower pack frame 1100 by a predetermined gap (G), and swelling that occurs in some of the battery cells 110 included in the battery cell assembly 100 can be effectively controlled. That is, even if some of the battery cells 110 swell due to swelling development, the pressure applied to the other battery cells 110 that did not experience swelling development can be relatively reduced through the predetermined gap (G), thereby preventing structural deformation of the battery cell assembly 100.

[0094] In the battery pack 1000 according to this embodiment, the upper part of the crossbeam 1200 may further include mounting holes 1200H formed at the same positions as the second coupling holes 205h included in the sub-crossbeam 200 of the battery cell assembly 100. That is, the other end of the bent portion 205 and the mounting holes 1200H of the crossbeam 1200 may be bolted to each other. Here, although not shown in Figure 5, the other end of the bent portion 205 and the upper part of the crossbeam 1200 are fastened to each other by inserting long bolt members into the second coupling holes 205h and the mounting holes 1200H.

[0095] Furthermore, the height of the crossbeam 1200 may be less than the height of the lower pack frame 1100. The sum of the height of the crossbeam 1200 and the thickness of the bent portion 205 may be the same as or less than the height of the lower pack frame 1100.

[0096] As a result, in the battery pack 1000 according to this embodiment, even if the other end of the bent portion 205 of the sub-crossbeam 200 included in the battery cell assembly 100 partially overlaps with the upper part of the crossbeam 1200, it does not affect the height or size of the battery pack 1000, thereby improving the spatial efficiency of the battery pack 1000.

[0097] Referring to Figures 2, 5, and 6, the battery cell assembly 100 according to this embodiment may further include a thermal resin layer 900 located between the battery cell stack 120 and the lower pack frame 1100. More specifically, the thermal resin layer 900 may be located between a cooling unit 710 located on the bottom surface of the lower pack frame 1100 and the battery cell stack 120. However, the cooling unit 710 may be omitted as shown in Figure 6.

[0098] As an example, the battery cell assembly 100 further includes a first thermal resin layer 900B applied between the lower surface of the battery cell stack 120 and the lower pack frame 1100, the first thermal resin layer 900B may extend to the bottom of the subcross beam 200. The battery cell assembly 100 also includes a second thermal resin layer 900A applied to the top of the battery cell stack 120, the second thermal resin layer 900A may extend to the top of the subcross beam 200.

[0099] The thermal resin layer 900 can be formed by curing a coated or injected thermal resin. Such a thermal resin may contain a thermally conductive adhesive, specifically at least one of silicon, urethane, and acrylic materials. The thermal resin is liquid when applied, but after curing, it can serve to fix one or more battery cells 110 that make up the battery cell laminate 120. It also has excellent thermal conductivity, allowing heat generated in the battery cells 110 to be quickly transferred to the lower pack frame 1100 (Figure 5).

[0100] As a result, in the battery cell assembly 100 according to this embodiment, if a thermal resin layer 900 is further included on the upper or lower part of the battery cell stack 120, the cooling performance of the battery pack 1000 can be further improved.

[0101] Furthermore, as shown in Figures 2 and 5, when connecting members 600 are formed on the upper and lower parts of the battery cell assembly 100, the thermal resin layer 900 is placed in the space between the connecting members 600 which are spaced apart from each other.

[0102] In this case, by placing the thermal resin layer 900 in the space between the interconnecting members 600 which are spaced apart from each other, the increase in height can be minimized, reducing spatial loss in the height direction and increasing the energy density of the battery pack.

[0103] In the battery pack 1000 according to this embodiment, referring to Figure 5, the battery pack 1000 according to this embodiment further includes a heat sink 700B which includes at least one cooling section 710 through which a refrigerant flows, and the heat sink 700B may be located at the bottom of the battery cell assembly 100. However, it is not limited to this, and a heat sink may also be located at the top of the battery cell assembly 100, or the heat sink 700B described above may be omitted as shown in Figure 6.

[0104] Each heatsink 700B may include at least one cooling section 710 through which a coolant flows. Here, the cooling section 710 of the heatsink 700B may be located below the first thermal resin layer 900B described above.

[0105] For example, the cooling section 710 may be a tubular member with an internal space, and such internal space may be a space through which a refrigerant flows. The refrigerant may be cooling water, and the heat sink 700B according to this embodiment may be a water-cooled cooling structure.

[0106] As a result, if the battery pack 1000 according to this embodiment further includes a heat sink 700B formed on the lower pack frame 1100, the cooling performance of the battery pack 1000 can be further improved.

[0107] As another example, as shown in Figures 2 and 5, when connecting members 600 are formed on the upper and lower parts of the battery cell assembly 100, the cooling portion 710 of the heat sink 700B is located on one side of the connecting member 600 at the lower part of the battery cell assembly 100. Specifically, the cooling portion 710 of the heat sink 700B can be placed in the space between the connecting members 600 which are spaced apart from each other.

[0108] This allows the cooling structure to be positioned in the space between the spaced-apart connecting members 600, minimizing the increase in height and reducing space loss in the height direction, thereby increasing the energy density of the battery pack.

[0109] The aforementioned battery cell assemblies and battery packs containing them can be applied to a variety of devices. Such devices are applied to means of transport such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and is applicable to a variety of devices in which battery cell assemblies and battery packs containing them can be used, and this also falls within the scope of the present invention.

[0110] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art, utilizing the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of symbols]

[0111] 100 Battery Cell Assembly 110 battery cells 120 Battery Cell Stack 150 Pad component 200 Subcrossbeam 201 Main body 205 Bend section 210 First sub-crossbeam 220 Second sub-crossbeam 300 End Plate 410, 420 Busbar Frame 600 Connecting member 900 Thermal resin layer 1000 Battery Pack 1100 Lower Pack Frame 1200 Crossbeam

Claims

1. Multiple battery cell assemblies, each including a battery cell stack formed by stacking multiple battery cells, wherein both sides and the top and bottom surfaces of the battery cell stack are exposed; A lower pack frame on which the plurality of battery cell assemblies are mounted; and It includes a crossbeam formed inside the lower pack frame and extending along between a pair of adjacent battery cell assemblies among the plurality of battery cell assemblies, The battery cell assembly includes a subcross beam in contact with at least one side of the battery cell stack, The aforementioned crossbeam and the aforementioned sub-crossbeam are separated from each other in this battery pack.

2. The battery cell assembly further includes busbar frames located on the front and rear surfaces of the battery cell stack, At both ends of the subcrossbeam, at least one first coupling hole is formed in the portion that overlaps with the busbar frame. The battery pack according to claim 1, wherein the subcrossbeam and the busbar frame are fixed via the first coupling hole.

3. The battery pack according to claim 2, wherein the subcrossbeam and the busbar frame are bolted together.

4. The aforementioned subcrossbeam includes a main body and a bent portion, The main body extends along the side surface of the battery cell stack, The battery pack according to claim 1, wherein one end of the bent portion is connected to the upper end of the main body, and the other end of the bent portion extends toward the upper part of the crossbeam.

5. The battery pack according to claim 4, wherein the other end of the bent portion overlaps with the upper part of the crossbeam.

6. The other end of the bent portion has at least one second bonding hole formed in the portion that overlaps with the upper part of the crossbeam. The battery pack according to claim 5, wherein the other end of the bent portion and the upper part of the cross beam are fixed via the second coupling hole.

7. The battery pack according to claim 6, wherein the other end of the bent portion and the upper part of the cross beam are bolted together.

8. The battery pack according to claim 4, wherein the height of the crossbeam is smaller than the height of the lower pack frame.

9. The battery pack according to claim 8, wherein the sum of the height of the crossbeam and the thickness of the bent portion is equal to or less than the height of the lower pack frame.

10. The aforementioned subcross beam includes a first subcross beam and a second subcross beam. The battery pack according to claim 1, wherein the first sub-cross beam is in contact with one side surface of the battery cell stack, and the second sub-cross beam is in contact with the other side surface of the battery cell stack.

11. The battery cell assembly further includes a first thermal resin layer applied between the lower surface of the battery cell stack and the lower pack frame, The battery pack according to claim 1, wherein the first thermal resin layer extends to the lower part of the subcross beam.

12. The battery cell assembly includes a second thermal resin layer applied to the upper part of the battery cell stack. The battery pack according to claim 11, wherein the second thermal resin layer extends to the upper part of the subcross beam.

13. The battery pack according to claim 1, further comprising a pad member located between the battery cell stack and the subcross beam, wherein the battery cell assembly further comprises a pad member located between the battery cell stack and the subcross beam.

14. A device comprising at least one battery pack as described in claim 1.

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