Battery pack and automobile including same

Abstract

The battery pack according to the present invention includes a cell unit group including a plurality of cell units stacked in one direction, a compression pad attached to one or both sides of each of the cell units, and a pair of surface pressure providing walls that sandwich the cell unit and the compression pad and press the cell unit and the compression pad together, and a pack case that houses at least one of the cell unit groups, wherein the surface pressure providing wall has a pin insertion portion at its lower end that is formed by indenting upward from the lower surface, and the pack case may include a guide pin portion that protrudes from a bottom plate and is inserted into the pin insertion portion to guide the surface pressure providing wall to a fixed position.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2022-0070524 filed on June 10, 2022 and Korean Patent Application No. 10-2023-0067180 filed on May 24, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings.

[0002] The present invention relates to a battery pack, and more particularly to a battery pack configured such that battery cells can be directly assembled to a pack case without the conventional assembly of battery modules. [Background technology]

[0003] Secondary batteries have attracted attention as a new energy source that is environmentally friendly and improves energy efficiency, since they not only have the temporary advantage of dramatically reducing the use of fossil fuels, but also have the advantage of producing absolutely no by-products associated with energy use.

[0004] For this reason, secondary batteries are increasingly being applied to a wide variety of devices. For example, they are widely used not only as energy sources for wireless mobile devices or wearable devices, which are multifunctional small products, but also as energy sources or energy storage systems (ESS) for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles.

[0005] Generally, the operating voltage of each secondary battery is about 2.5V to 4.5V. Therefore, in the case of electric vehicles and power storage devices that require large capacity and high output, a battery module is configured by connecting a plurality of secondary batteries in series and / or parallel and housing the battery module in a module housing, and a battery pack is configured by connecting the battery modules in series and / or parallel, and these are used as an energy source. That is, a conventional battery pack includes a battery module as a subordinate concept, and a battery module includes a battery cell as a subordinate concept. The number of battery cells in one battery module or the number of battery modules in one battery pack can be determined in various ways depending on the output and capacity of the battery pack required for the electric vehicle.

[0006] Meanwhile, for example, a battery module 2 of a battery pack 1 for an electric vehicle includes a battery cell 3, a bus bar frame (not shown) for electrically connecting the battery cells, and a module housing 4 for accommodating the battery cell and the bus bar frame together. As shown in Figs. 1 and 2, the battery module is disposed in an internal space 5 of a pack tray and may be fixed to a bottom surface of the pack tray by bolts or the like. In general, the pack tray may include a plurality of beam frames 6 to increase durability against impact and vibration. The beam frames extend from one wall surface of the pack tray and are coupled to the other wall surface, and may play a role in suppressing twisting and distortion of the pack tray. The pack tray may have an internal space defined by the beam frames, and the battery modules may be disposed in the defined spaces, respectively.

[0007] However, in the case of a battery pack in which a battery module is mounted on a pack tray, it has been pointed out that a dead space corresponding to a gap between the battery module and the beam frame, the weight and volume of the module housing, etc. act as factors that reduce the energy density per unit volume of the battery pack, making it difficult to dramatically increase the energy capacity of the battery pack. However, in recent years, as the electric vehicle market has grown rapidly, the travel distance of electric vehicles has become important. The travel distance of electric vehicles is largely determined by the energy capacity of the battery pack. Therefore, in the industry, it remains a major issue to provide a method that can increase the energy density per unit volume of a battery pack. For this reason, in recent years, a so-called cell-to-pack type battery pack has been attracting attention, which is a method of directly mounting a battery cell on a pack tray without using a module housing, i.e., a battery module fabrication step is omitted and the battery cell is directly mounted on the pack tray.

[0008] However, because cell-to-pack does not use a module housing, battery cells must be mounted and fixed in the battery pack in a completely different manner than conventional methods. Furthermore, the battery cells must be restrained to prevent free movement even when subjected to external shock or vibration, and swelling of the battery cells during charging and discharging must be controlled. Therefore, there is a strong demand for a cell-to-pack battery pack that can maintain the structural stability of the battery cells when subjected to shock or vibration, and can also control swelling of the battery cells. Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, a technical problem to be solved by the present invention is to provide a cell-to-pack (CTP) type battery pack in which battery cells can be easily accommodated in a pack case and the battery cells can be restrained to ensure structural stability despite vibration or impact.

[0010] The technical problems that the present invention aims to solve are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0011] According to one aspect of the present invention, a battery pack can be provided that includes a cell unit group including a plurality of cell units stacked in one direction, a compression pad attached to one or both sides of each of the cell units, and a pair of surface pressure providing walls that sandwich the cell unit and the compression pad between them and press the cell unit and the compression pad together, and a pack case that houses at least one of the cell unit groups, wherein the surface pressure providing wall has a pin insertion portion at its lower end that is formed by indenting upward from the lower surface, and the pack case includes a guide pin portion that protrudes from a bottom plate and is inserted into the pin insertion portion to guide the surface pressure providing wall to a fixed position.

[0012] The pack case includes a pack tray having a bottom plate and a plurality of beam frames arranged perpendicular to the bottom plate to form walls, and the cell unit group is placed on the pack tray with the compression pad compressed, and one of the pair of surface pressure providing walls faces one of the two opposing beam frames, and the other of the pair of surface pressure providing walls faces the other of the two opposing beam frames.

[0013] The two opposing beam frames may be configured to support the surface pressure providing walls facing each other, so that a reaction force against the restoring force of the compression pad acts on the surface pressure providing walls.

[0014] The guide pin portion may be provided at a position spaced a predetermined distance from the beam frame and configured to be aligned with the beam frame.

[0015] The guide pin portion may be provided so as to have a width smaller than that of the pin insertion portion and may be configured to be relatively movable in the width direction inside the pin insertion portion.

[0016] The guide pin portion may have a vertical cross section formed in a trapezoidal shape that is narrow at the top and wide at the bottom.

[0017] The guide pin portion may have a longitudinal section formed in an arc shape, and a surface facing the cell unit may be configured to be perpendicular to the bottom plate.

[0018] The surface pressure providing wall may include a ball member rollably coupled to a lower end portion.

[0019] The cell unit group may be configured such that, with the compression pad in a compressed state, it is placed between two beam frames facing each other on the bottom plate, and the surface pressure providing wall is pushed out and contacts the beam frame as the compression state of the compression pad is relaxed.

[0020] The guide pin portion may be formed integrally with the bottom plate.

[0021] The pin receptacle may include a shock absorbing pad attached to an interior surface.

[0022] The cell unit may include a cell stack consisting of one or two or more stacked battery cells, and a cell cover provided to cover both side portions of the cell stack along the width direction of the cell stack and an upper portion of the cell stack.

[0023] The battery cell may be a pouch-type battery cell.

[0024] The base plate may include cooling channels therein through which a coolant can flow.

[0025] According to another aspect of the invention, there may be provided a vehicle including a battery pack as described above. Effect of the Invention

[0026] According to the present invention, it is possible to provide a cell-to-pack type battery pack in which battery cells can be easily accommodated in a pack case, the battery cells can be restrained to ensure structural stability despite vibration or impact, and excessive swelling of the battery cells during charging and discharging can be restricted to prevent deterioration of the performance of the battery cells.

[0027] Furthermore, the battery pack according to the present invention can have a larger energy capacity than a conventional battery pack because the battery cells can be collectively accommodated in the pack case.

[0028] In addition to these, the present invention can have various other effects, which will be described in the sections for each embodiment, and descriptions of effects that can be easily inferred by a person skilled in the art will be omitted. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a battery pack according to the prior art. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the battery pack of FIG. 1. [Diagram 3] 1 is a perspective view illustrating a schematic configuration of a battery pack according to an embodiment of the present invention; [Figure 4]FIG. 2 is a schematic diagram illustrating a cell unit group according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a perspective view of a cell unit according to one embodiment of the present invention. [Figure 6] FIG. 6 is an exploded perspective view of the cell unit of FIG. 5. [Figure 7] 2 is an enlarged view showing an area inside the pack tray according to one embodiment of the present invention with a portion of the wall of the pack tray omitted. FIG. [Figure 8] 11A to 11C are diagrams illustrating a process in which a cell unit group is accommodated in a pack case according to an embodiment of the present invention. [Figure 9] 11A to 11C are diagrams illustrating a process in which a cell unit group is accommodated in a pack case according to an embodiment of the present invention. [Figure 10] FIG. 10 corresponds to FIG. 9 and shows a modified example of the guide pin portion according to the embodiment of the present invention. [Figure 11] FIG. 10 corresponds to FIG. 9 and shows a modified example of a surface pressure providing wall according to an embodiment of the present invention. [Figure 12] 1 is a schematic diagram of a vehicle according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in the present specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0031] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0032] Figure 3 is an oblique view showing a schematic configuration of a battery pack according to one embodiment of the present invention, Figure 4 is a diagram showing a schematic configuration of a cell unit group according to one embodiment of the present invention, Figure 5 is an oblique view of a cell unit according to one embodiment of the present invention, Figure 6 is an exploded oblique view of the cell unit of Figure 5, and Figure 7 is an enlarged view of an area inside the pack tray according to one embodiment of the present invention, with part of the wall of the pack tray omitted.

[0033] Referring to FIG. 3, a battery pack according to an embodiment of the present invention includes a cell unit group 10 and a pack case 20.

[0034] As shown in FIG. 4, the cell unit group 10 includes a cell unit 100 stacked in one direction, a compression pad P1 attached to one or both sides of the cell unit 100, and a pair of surface pressure providing walls 200 that sandwich the cell unit 100 and the compression pad P1 and provide surface pressure to the cell unit 100 and the compression pad P1.

[0035] The cell unit 100 may refer to an energy storage body including one or more stacked battery cells 110 or a cell cover 120 housing the one or more battery cells 110.

[0036] Specifically, referring to FIG. 5 and FIG. 6, the cell unit 100 according to this embodiment includes a cell stack consisting of one or two or more stacked pouch-type battery cells 110, and a cell cover 120 that encloses the remaining part of the cell stack except for the front side, rear side, and lower side where the electrode lead 111 is located. In other words, the cell cover 120 may be configured to cover both side portions and the upper side of the cell stack along the width direction (±X direction) of the cell stack. In addition, the cell unit 100 includes a terminal bus bar 131 electrically connected to the electrode lead 111 of the pouch-type battery cell 110, and a bus bar frame assembly 130 that supports the terminal bus bar 131 and covers the front open end and rear open end of the open cell cover 120. That is, the cell unit 100 according to this embodiment has the bus bar frame assembly 130 on the front side and rear side, respectively. However, unlike this embodiment, the cell unit 100 may be composed of only a cell stack and a cell cover 120. In this case, a bus bar frame assembly 130 may be used that is capable of stacking a plurality of cell units 100 in one direction and collectively covering the front and rear sides of the stacked cell units 100.

[0037] 6, the pouch-type battery cell 110 includes an electrode assembly, a pouch case that houses the electrode assembly, and an electrode lead 111 that is connected to the electrode assembly and extends to the outside of the pouch case. The electrode lead 111 includes a pair of a positive electrode lead and a negative electrode lead. Here, the positive electrode lead and the negative electrode lead may be provided at both ends of the battery cell 110 along the longitudinal direction (Y direction) of the battery cell 110.

[0038] Such pouch-type battery cells 110 may be stacked in one direction (X direction) in a predetermined number, with the wide surface being vertical to the ground. For example, as shown in FIG. 6, three pouch-type battery cells 110 may be stacked in one direction (X direction). At this time, the positive electrode lead of each pouch-type battery cell 110 faces forward (-Y direction), and the negative electrode lead of each pouch-type battery cell 110 faces backward (+Y direction). In this case, the three pouch-type battery cells 110 may be connected in parallel by welding the electrode leads 111 of the same polarity to the terminal bus bar 131 located on the corresponding side, forming one power bank.

[0039] That is, the three pouch-type battery cells 110 may be housed in the cell cover 120 to maintain a stacked state, and may be connected in parallel via the terminal bus bar 131 of the bus bar frame assembly 130. The terminal bus bar 131 may be configured such that its upper end is also exposed to the outside of the bus bar housing 132, and the upper end of the terminal bus bar 131 may function as a positive terminal or a negative terminal of the cell unit 100.

[0040] In this embodiment, the cell unit 100 is configured using three pouch-type battery cells 110, but one, two, or four or more pouch-type battery cells 110 may be used to configure the cell unit 100. Although not shown, for example, six pouch-type battery cells 110 may be used to connect three pouch-type battery cells 110 in parallel, and two groups of three pouch-type battery cells 110 connected in parallel in this manner may be connected in series to configure the six pouch-type battery cells 110 in a so-called "3P2S" configuration. In this case, the cell unit 100 may be configured to have its positive terminal and negative terminal in the same direction.

[0041] Meanwhile, the pouch-type battery cell 110 may include a housing portion R corresponding to a portion that houses an electrode assembly inside a pouch case, and four edge portions E1 to E4 that surround the housing portion R. The four edge portions E1 to E4 refer to, for example, an upper edge portion E1, a lower edge portion E2, a front edge portion E3, and a rear edge portion E4 based on the housing portion R in a pouch-type battery cell 110 that is arranged upright as shown in Fig. 6 .

[0042] Here, the edge portions E1 to E4 may all be sealing portions, or the remaining three edge portions E2, E3, E4 or E1, E3, E4 excluding the upper edge portion E1 or the lower edge portion E2 may be sealing portions. In more detail, the pouch-type battery cell 110 using a method of folding one laminate film to accommodate an electrode assembly has three sealing portions, and the pouch-type battery cell 110 using a method of joining the peripheries of two laminate films has four sealing portions. Thus, in the pouch-type battery cell 110, the three edge portions E2, E3, E4 or E1, E3, E4 may be sealing portions, or the four edge portions E1 to E4 may all be sealing portions.

[0043] The cell cover 120 may be configured to enclose at least a portion of one or two or more stacked pouch-type battery cells 110. For example, the cell cover 120 configured to enclose one pouch-type battery cell 110 may be fabricated in a shape that encloses both sides of the upper edge portion E1 and the receiving portion R of the pouch-type battery cell 110. Alternatively, as shown in FIG. 6, the cell cover 120 according to the present embodiment may be fabricated in a shape that can enclose and cover the upper edge portion E1 of the three pouch-type battery cells 110, one side of the receiving portion R of the first pouch-type battery cell 110 in the stacking order, and one side of the receiving portion R of the third pouch-type battery cell 110.

[0044] The cell cover 120 may be made of a variety of materials. In particular, the cell cover 120 may be made of a metal material to ensure rigidity. In the case of a metal material, the stacked state of the pouch-type battery cells 110 can be more stably maintained and the pouch-type battery cells 110 can be more securely protected from external impact. For example, the entire cell cover 120 may be made of a stainless steel (SUS) material or an alloy including stainless steel.

[0045] The pouch-type battery cell 110 has a pouch case made of a soft material, and is therefore vulnerable to external impacts and has low hardness. Therefore, it is not easy to accommodate only the pouch-type battery cell 110 inside the pack case 20. For this reason, a cell cover 120 is used, and the cell cover 120 allows the pouch-type battery cells 110 to stably maintain their stacked and upright states.

[0046] In addition, the cell cover 120 prevents the pouch-type battery cells 110 from being damaged or broken due to external impact, and in particular, enables the stacked state of the pouch-type battery cells 110 to be stably maintained when the pouch-type battery cells 110 are housed in the pack case 20.

[0047] More specifically, the configuration of the cell cover 120 according to this embodiment will be described. As shown in FIG. 6, the cell cover 120 includes an upper cover portion 121, a first side cover portion 122, and a second side cover portion 123.

[0048] The upper cover part 121 may be configured to enclose an upper edge part E1 of the pouch-type battery cell 110 housed therein. The upper cover part 121 may be configured to be in contact with and separated from the upper edge part E1 of the pouch-type battery cell 110. The first side cover part 122 may be configured to have a shape extending downward from one edge line along the width direction of the upper cover part 121. For example, the first side cover part 122 may be configured to have a shape extending downward from the left end part of the upper cover part 121 longer than the receiving part R of the pouch-type battery cell 110.

[0049] The first side cover portion 122 may be configured to cover one side of the at least one pouch-type battery cell 110. For example, the first side cover portion 122 may be configured to enclose one side of the containing portion R of the first pouch-type battery cell 110 in FIG.

[0050] The second side cover part 123 may be configured to have a shape extending downward from the other edge line along the width direction of the upper cover part 121. For example, the second side cover part 123 may be configured to have a shape extending downward from the right end part of the upper cover part 121 longer than the housing part R of the pouch-type battery cell 110.

[0051] The second side cover portion 123 may be configured to cover one side of the at least one pouch-type battery cell 110. For example, the second side cover portion 123 may be configured to enclose one side of the containing portion R of the third pouch-type battery cell 110 in FIG.

[0052] The distance between the first side cover part 122 and the second side cover part 123 may be determined within a range in which the pouch-type battery cell 110 housed inside the cell cover 120 can be compressed.

[0053] According to the configuration of the cell cover 120, the pouch-type battery cell 110 can be compressed inside the cell cover 120, and the lower edge portion of the pouch-type battery cell 110 is exposed to the outside. Therefore, when the cell unit 100 is placed on the bottom plate 24 of the pack case 20, the lower edge portion of the pouch-type battery cell 110 can directly face the bottom plate 24 of the pack case 20. In this case, heat exchange between the lower edge portion of the pouch-type battery cell 110 and the bottom plate 24 of the pack case 20 can be more smoothly performed. In addition, the heat transfer rate between the lower edge portion of the pouch-type battery cell 110 and the bottom plate 24 of the pack case 20 can be increased by applying a thermally conductive adhesive G or the like to the bottom plate 24 of the pack case 20. That is, according to the embodiment, in which the cell cover 120 is not used to cover the lower part of the pouch-type battery cell 110, the stacked state of the pouch-type battery cells 110 can be stably maintained and the pouch-type battery cells 110 can be mounted in the pack case 20; furthermore, cooling of the pouch-type battery cells 110 is easy and efficiently performed.

[0054] Also, the cell cover 120 may be provided in a shape in which the front side, rear side, and bottom side are open. And, the cell cover 120 of this embodiment may include cutout portions 124 in which both end portions of the upper end are arranged in a cutout shape as shown in FIG. 6. By using such cutout portions 124, as shown in FIG. 5, the bus bar frame assembly 130 can be pulled inward of the cell cover 120, and the upper end portion bent from the terminal bus bar 131 can be exposed toward the upper portion of the cell cover 120. In this way, by configuring the electrode terminals of the cell unit 100 to face the upper direction, the convenience of connection with other cell units 100 or external devices can be improved.

[0055] The busbar frame assembly 130 includes a first busbar frame assembly and a second busbar frame assembly. The first busbar frame assembly and the second busbar frame assembly have substantially the same configuration, and as shown in FIGS. 5 to 6, the first busbar frame assembly may be disposed at one end (-Y direction) along the longitudinal direction of the cell cover 120, and the second busbar frame assembly may be disposed at the other end (+Y direction) of the cell cover 120. As described above, in this embodiment, the positive electrode leads of the three stacked pouch-type battery cells 110 may be integrally welded to the terminal bus bar 131 of the first busbar frame assembly, and the negative electrode leads may be integrally welded to the terminal bus bar 131 of the second busbar assembly. In this case, the three pouch-type battery cells 110 may be connected in parallel in a 3P1S configuration.

[0056] The bus bar frame assembly 130 may include, as main components, a terminal bus bar 131, a bus bar housing 132, a housing cover 133, and an insulating sheet 134, as shown in FIG.

[0057] The terminal bus bars 131 may be made from a metal such as, for example, copper, nickel, aluminum, etc., and the bus bar housings 132 may be made from an electrically insulating material such as, for example, plastic.

[0058] The bus bar housing 132 supports the terminal bus bar 131 and may be coupled to the cell cover 120. That is, the bus bar housing 132 may be configured to be coupled to a front open end and a rear open end of the cell cover 120, as shown in Fig. 5. At this time, the bus bar housing 132 may be coupled to be fixed to the cell cover 120 using a variety of fastening methods, such as adhesion, welding, fitting, hook-fitting, bolting, and riveting.

[0059] The bus bar housing 132 may be provided in a box shape having a substantially rectangular parallelepiped structure. The bus bar housing 132 may have a slit into which the electrode lead 111 of the battery cell 110 can be inserted so that the electrode lead 111 can pass through the body. Thus, the electrode lead 111 of the battery cell 110 may be pulled out through the bus bar housing 132 through the slit, and the pulled out portion may be attached to the terminal bus bar 131. When the electrode lead 111 is attached to the terminal bus bar 131, laser welding may be performed. Then, the portion where the electrode lead 111 and the terminal bus bar 131 are joined may be shielded by a housing cover 133. An insulating sheet 134 may be further attached to the outside of the housing cover 133. The insulating sheet 134 may be made of a flame-retardant material such as mica.

[0060] The cell unit 100 according to an embodiment of the present invention may be constructed as described above, and a compression pad P1 may be attached to one or both sides of the cell unit 100. The compression pad P1 may be made of a material that can be compressed by an external force and can restore its original shape when the external force is released. For example, the compression pad P1 may be made of a material such as rubber, silicone, or memory foam.

[0061] 4, the cell units 100 with the compression pads P1 attached are stacked in one direction (X direction) facing each other, and a surface pressure providing wall 200 is disposed on the outermost side of the stack of the stacked cell units 100. That is, a cell unit group 10 according to one embodiment of the present invention includes a plurality of cell units 100, buffer pads P2 disposed between the cell units 100, and surface pressure providing walls 200 disposed on both sides of the outermost edge of the cell units 100 in the stacking direction.

[0062] The surface pressure providing wall 200 is a component used to make it easy to accommodate the stacked cell units 100 together in the pack case 20, and to ensure structural stability against vibration and impact by restraining the cell units 100 from moving freely after they are accommodated in the pack case 20.

[0063] For example, the cell units 100 may be accommodated one by one without using the surface pressure providing wall 200. However, this is not effective as it takes a long time to complete the work. In addition, the pouch-type battery cell 110 has a problem that the accommodation portion R swells during overcharging and overdischarging, which acts as a factor in the deterioration of performance. This swelling phenomenon can be suppressed or alleviated by compressing the pouch-type battery cell 110 with an appropriate pressure. However, if the cell unit 100 is directly mounted in the pack case 20 without any compression device, it is difficult to suppress the swelling of the battery cell 110, and furthermore, it cannot be said that there is no room for problems with structural and electrical stability as the position of the battery cell 110 becomes unstable due to external impact or vibration.

[0064] For this reason, in the battery pack according to the present invention, the cell unit group 10 includes the pair of surface pressure providing walls 200, and when the cell unit group 10 is gripped as a whole using a robot arm (not shown) or a gripping jig (not shown) and placed on the pack case 20, the pair of surface pressure providing walls 200 are configured to provide a uniform surface pressure to the stacked battery cells 110. Hereinafter, the components of the present invention and their functions for this purpose will be described in more detail.

[0065] Returning to FIG. 3, the pack case 20 may include a pack tray 22 and a pack cover 21.

[0066] The pack tray 22 includes a bottom plate 24 and a plurality of beam frames 23 that are arranged perpendicular to the bottom plate 24 and form a wall. The plurality of beam frames 23 may include an outer beam frame 23a that forms a wall along the outer periphery of the bottom plate 24, and an inner beam frame 23b that crosses the bottom plate 24 on the inside of the bottom plate 24 to define the internal space of the pack tray 22.

[0067] Each cell unit group 10 may be placed in an internal space of the pack tray 22 defined by being surrounded by the plurality of beam frames 23. For example, as shown in Fig. 3, each cell unit group 10 may be placed in an internal space of the pack tray 22 surrounded by the outer beam frame 23a and the inner beam frame 23b of the pack tray 22. Meanwhile, the pack tray 22 is configured to accommodate four cell unit groups 10 according to this embodiment, but the pack tray 22 may be configured to accommodate less than four or more than four cell unit groups 10 by changing the area of ​​the bottom plate 24 of the pack tray 22 or the number and positions of the outer beam frames 23a and the inner beam frames 23b.

[0068] The cell unit group 10 can be placed on the pack tray 22 with the compression pad P1 compressed, and one of the pair of surface pressure providing walls 200 can be placed so as to face one of the two opposing beam frames 23, and the other of the pair of surface pressure providing walls 200 can be placed so as to face the other of the two opposing beam frames 23.

[0069] In this case, the battery pack according to the present invention may be configured such that the two opposing beam frames 23 support the pair of surface pressure-providing walls 200 facing each other, and a reaction force against the restoring force of the compression pad P1 acts on the surface pressure-providing walls 200.

[0070] This will be explained in more detail primarily with reference to FIGS. 7-9 in conjunction with FIG.

[0071] 3, the surface pressure-providing wall body 200 has a pin insertion portion 201 at its lower end. The pin insertion portion 201 can be specified as an empty space formed inside the surface pressure-providing wall body 200 by indenting upward from the lower surface of the surface pressure-providing wall body 200. Such a pin insertion portion 201 can be disposed in a shape extending elongated along the longitudinal direction of the surface pressure-providing wall body 200.

[0072] The pack case 20 may include a guide pin portion 25 that is protruded from the bottom plate 24 at a pre-specified position and is inserted into the pin insertion portion 201 to guide the surface pressure providing wall body 200 to a fixed position.

[0073] The guide pin portion 25 is formed integrally with the pack tray 22 and aligned with the beam frame 23, and can be provided at a position that can correspond to the pin insertion portion 201 of the surface pressure providing wall body 200 in the vertical direction when the cell unit group 10 is placed on the pack tray 22.

[0074] More specifically, two guide pin portions 25 may be provided on the bottom plate 24 of the pack tray 22 for each defined internal space of the pack tray 22 on which each cell unit group 10 is to be placed. In this embodiment, one of the two guide pin portions 25 may be provided at a position spaced apart by an amount corresponding to a predetermined interval in the outer beam frame 23a, and the other of the two guide pin portions 25 may be provided at a position spaced apart by an amount corresponding to a predetermined interval in the inner beam frame 23b. Here, the predetermined interval may be determined in consideration of the thickness of the surface pressure providing wall body 200, the degree of compression of the compression pad P1, and the like. However, the predetermined interval may be determined within a range smaller than the left-right width (±X direction) of the pin insertion portion 201 of the surface pressure providing wall body 200.

[0075] The guide pin portion 25 may have a length corresponding to the surface pressure-providing wall body 200, and its vertical cross section may be formed into a trapezoid shape that is narrow at the top and wide at the bottom. In this case, in the process of placing the surface pressure-providing wall body 200 on the pack tray 22, the guide pin portion 25 is easily inserted into the pin insertion portion 201 of the surface pressure-providing wall body 200. At this time, if the pin insertion portion 201 is also a trapezoid shape corresponding to the guide pin portion 25, the insertion of the guide pin portion 25 into the pin insertion portion 201 can be performed much more easily.

[0076] Also, the guide pin portion 25 may be provided so as to have a width smaller than that of the pin insertion portion 201. In this case, when the cell unit group 10 is placed on the pack tray 22, not only is it easier for the guide pin portion 25 to be inserted into the pin insertion portion 201 of the surface pressure providing wall body 200, but after the guide pin portion 25 is inserted into the pin insertion portion 201, the guide pin portion 25 can move relatively in the width direction inside the pin insertion portion 201.

[0077] According to the above configuration, as shown in Fig. 8, when the cell unit group 10 is compressed using a gripping jig (not shown) and then placed on the pack tray 22, if the compression is released, the restoring force of the compression pad P1 can push and move the surface pressure providing wall 200 in the ±X directions as shown by the arrows in Fig. 9. That is, the cell unit group 10 according to this embodiment is placed between the two beam frames 23 facing each other on the bottom plate 24 with the compression pad P1 in a compressed state, and as the compressed state of the compression pad P1 is relaxed, the surface pressure providing wall 200 can be pushed in the direction in which the restoring force of the compression pad P1 acts and come into contact with the beam frame 23.

[0078] 8, the cell unit group 10 may be provided with a compression pad P1 and placed on the bottom plate 24 of the pack tray 22 in a compressed state. At this time, the positions of two guide pin parts 25 on the pack tray 22 and the distance between them may be a measure for determining the degree of compression and the loading position of the cell unit group 10. In addition, since there is a gap between the beam frame 23 of the pack tray 22 and the guide pin part 25, and the width of the guide pin part 25 is formed to be smaller than the pin insertion part 201 of the surface pressure providing wall 200, the cell unit group 10 may be placed on the bottom plate 24 of the pack tray 22 without contacting the inner surface of the pin insertion part 201 of the surface pressure providing wall 200 and the guide pin part 25. In this state, after the cell unit group 10 is placed on the pack tray 22, the compression applied to the cell unit group 10 is released (by the gripping jig), and the restoring force of the compression pad P1 acts to push the surface pressure providing wall 200 in the direction opposite to the compression direction, causing it to move toward the beam frame 23.

[0079] Then, as shown in FIG. 9, the surface pressure providing wall 200 comes into face-to-face contact with the beam frame 23 and stops moving. At this time, the movable distance of the surface pressure providing wall 200 can be limited within the range of the difference in width between the guide pin portion 25 and the pin insertion portion 201. In addition, a buffer pad P2 can be attached to at least one of one side surface of the guide pin portion 25 and one side surface of the pin insertion portion 201 that face each other. The buffer pad P2 can absorb the impact caused by the contact between the guide pin portion 25 and the pin insertion portion 201, and can be compressed between the guide pin portion 25 and the inner side surface of the pin insertion portion 201. Therefore, the assembly tolerance that may occur depending on the relative positions between the surface pressure providing wall 200, the beam frame 23, and the guide pin portion 25 can be eliminated by the compression of the buffer pad P2.

[0080] According to one embodiment of the present invention, two opposing beam frames 23 support the pair of surface pressure-providing walls 200 facing each other, and a reaction force against the restoring force of the compression pad P1 can act on the surface pressure-providing walls 200.

[0081] Therefore, the reaction force of the surface pressure providing walls 200 acts on the cell unit 100, so that the cell unit 100 can be firmly held. Therefore, each cell unit group 10 mounted on the pack tray 22 is structurally stable despite external shocks and vibrations. In addition, when swelling of the battery cell 110 occurs during charging and discharging operations, the reaction force of the pair of surface pressure providing walls 200 can suppress or mitigate the swelling of the battery cell 110.

[0082] 8 and 9, the bottom plate 24 of the pack tray 22 may be configured to have cooling channels 26 inside which a refrigerant can flow. By applying a thermally conductive adhesive G onto such a bottom plate 24 and disposing the cell unit 100 on the thermally conductive adhesive G, the heat generated from the battery cells 110 can be more effectively conducted to the bottom plate 24 of the pack tray 22, thereby increasing the cooling efficiency for the battery cells 110.

[0083] FIG. 10 corresponds to FIG. 9 and shows a modified example of the guide pin portion 25 according to one embodiment of the present invention, and FIG. 11 corresponds to FIG. 9 and shows a modified example of the surface pressure-providing wall body 200 according to one embodiment of the present invention.

[0084] Next, a modified example of the present invention will be briefly described with reference to FIGS.

[0085] The same component numbers as those in the previously described embodiment indicate the same components, and duplicated descriptions of the same components will be omitted, with the focus being on the differences from the previously described embodiment.

[0086] The guide pin portion 25 on the pack tray 22 described above is not necessarily trapezoidal as in the above embodiment. The guide pin portion 25 may be manufactured in a variety of shapes other than a trapezoidal shape. For example, as shown in FIG. 10, the guide pin portion 28 may have an arc-shaped longitudinal section. More specifically, the guide pin portion 28 may have a fan-shaped cross section with an angle of 90°, and the surface facing the cell unit 100 may be configured to be perpendicular to the bottom plate 24 of the pack tray 22. The pin insertion portion 201 of the surface pressure providing wall 200 may have an internal space configured to be rectangular. In this case, when the surface pressure providing wall body 200 is placed, its lower end can be lowered by resting on the arc portion of the guide pin portion 25, and since the vertical surface of the guide pin portion 28 and the inner surface of the pin insertion portion 201 face each other horizontally, the reaction force acting between the guide pin portion 28 and the inner surface of the pin insertion portion 201 can act more uniformly and stably in the horizontal direction.

[0087] Meanwhile, as shown in Fig. 11, the surface pressure-providing wall 200 according to the modified example may further include a ball member 202 rollably coupled to a lower end portion. As described above, when the cell unit group 10 is placed on the bottom plate 24 of the pack tray 22 with the compression pad P1 in a compressed state, and the restoring force of the compression pad P1 acts to push the surface pressure-providing wall 200 toward the beam frame 23, the surface pressure-providing wall 200 according to the modified example may move with almost no friction with the bottom plate 24 of the pack tray 22 due to the rotation of the ball member 202. The ball member 202 may include, for example, a ball bearing.

[0088] According to the configuration of this modified example, the frictional force between the bottom plate 24 of the pack tray 22 and the surface pressure providing wall 200 is significantly reduced, so that the surface pressure providing wall 200 is supported more firmly by the beam frame 23, and the reaction force of the surface pressure providing wall 200 acts on the cell unit 100 without loss, thereby more strongly restraining the cell unit 100.

[0089] Meanwhile, the battery pack may further include a control module 30. The control module 30 may include a battery management system (BMS) for managing the charge / discharge operation, state of charge (SOC), state of health (SOH), and the like of the battery cells 110, and may be installed in the internal space of the pack case 20. The battery pack may further include a switching unit 40. The switching unit 40 may be configured to control an electrical connection between the battery pack and an external circuit. To this end, the switching unit 40 may selectively include a current sensor, a power relay, a fuse, and the like.

[0090] Such a battery pack according to the present invention may be used as a power energy source for an automobile. That is, an automobile V according to the present invention may include the above-described battery pack according to the present invention, as shown in FIG. 12. Here, the automobile according to the present invention may include a specific automobile that uses electricity as a drive source, such as an electric automobile or a hybrid automobile. Furthermore, the automobile according to the present invention may further include various other components included in the automobile, such as a vehicle body and a motor, in addition to the battery pack according to the present invention.

[0091] Meanwhile, although directional terms such as up, down, left, right, front, and back are used in this specification, it will be obvious to those skilled in the art of the present invention that these terms are used merely for ease of explanation and may vary depending on the position of the object in question, the position of the observer, etc.

[0092] Although the present invention has been described above using limited embodiments and drawings, it goes without saying that the present invention is in no way limited to these, and that a person having ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations within the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0093] 1 Battery Pack 2 Battery Module 3 Battery Cells 4 Module Housing 5. Interior Space 6 Beam Frame 10 Cell Unit Group 20 pack case 21 Pack Cover 22 Pack Tray 23 Beam Frame 23a Outer beam frame 23b Inner beam frame 24 Bottom plate 25 Guide pin part 26 Cooling Channels 28 Guide pin part 30 Control Module 40 Switching Unit 100 cell units 110 Battery Cell 111 Electrode lead 120 Cell Cover 121 Upper cover part 122 first side cover part 123 Second side cover part 124 Notch 130 Bus bar frame assembly 131 Terminal busbar 132 Busbar housing 133 Housing cover 134 Insulation sheet 200 Surface pressure providing wall 201 Pin insertion part 202 Ball member arc CTP Cell-to-Pack E1~E4 Edge section E1 Edge section E1 Upper edge E2, E3, E4 or E1, E3, E4 Edge E2 Edge section E2 Lower edge E3 Edge section E4 Edge section ESS Power Storage Device P1 Compression Pad P2 Cushioning Pad R Storage section

Claims

1. a cell unit group including a plurality of cell units arranged in a stack in one direction, a compression pad attached to one or both sides of each of the cell units, and a pair of surface pressure providing walls sandwiching the cell unit and the compression pad therebetween and pressing the cell unit and the compression pad together; a pack case that accommodates at least one of the cell unit groups; Including, The surface pressure providing wall body has a pin insertion portion formed at a lower end thereof by being indented upward from a lower surface thereof, The pack case includes a guide pin portion that protrudes from a bottom plate and is inserted into the pin insertion portion to guide the surface pressure providing wall to a fixed position.

2. The pack case includes: a pack tray including a bottom plate and a plurality of beam frames arranged perpendicular to the bottom plate to form a wall, the cell unit group is placed on the pack tray with the compression pad compressed; 2. The battery pack according to claim 1, wherein one of the pair of surface pressure providing walls faces one of the two opposing beam frames, and the other of the pair of surface pressure providing walls faces the other of the two opposing beam frames.

3. 3. The battery pack according to claim 2, wherein the two opposing beam frames support the opposing surface pressure providing walls so that a reaction force against the restoring force of the compression pad acts on the surface pressure providing walls.

4. The battery pack according to claim 2 , wherein the guide pin portion is provided at a position spaced a predetermined distance from the beam frame and aligned with the beam frame.

5. The battery pack according to claim 1 , wherein the guide pin portion is provided so as to have a width smaller than that of the pin insertion portion and is configured to be relatively movable in the width direction inside the pin insertion portion.

6. The guide pin portion is 6. The battery pack according to claim 5, wherein the longitudinal section is formed into a trapezoidal shape narrower at the top and wider at the bottom.

7. The battery pack according to claim 5 , wherein the guide pin portion has a longitudinal section formed in an arc shape, and a surface facing the cell unit is perpendicular to the bottom plate.

8. The battery pack according to claim 5 , wherein the surface pressure providing wall includes a ball member rollably coupled to a lower end thereof.

9. 3. The battery pack according to claim 2, wherein the cell unit group is placed between the two beam frames facing each other on the bottom plate with the compression pad in a compressed state, and the surface pressure providing wall is pushed out and contacts the beam frame as the compression state of the compression pad is relaxed.

10. The battery pack according to claim 1 , wherein the guide pin portion is integrally formed with the bottom plate.

11. The battery pack of claim 1 , wherein the pin receptacle includes a shock-absorbing pad attached to an inner surface thereof.

12. The cell unit is A cell stack consisting of one or more stacked battery cells; a cell cover provided to cover both side surfaces of the cell stack along a width direction of the cell stack and an upper portion of the cell stack; 10. The battery pack of claim 1 , comprising:

13. 13. The battery pack of claim 12, wherein the battery cells are pouch-type battery cells.

14. The battery pack according to claim 1 , wherein the bottom plate includes a cooling channel therein through which a coolant can flow.

15. A motor vehicle comprising a battery pack according to any one of claims 1 to 14.

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