Battery pack and vehicle including the same

Abstract

A battery pack according to the present invention comprises: a plurality of cell units stacked in one direction; a compression pad attached to one side or both sides of each cell unit; a cell unit group including a pair of surface pressure providing walls that integrally compress the cell units and the compression pads with the cell units and the compression pads in between; and a pack case accommodating at least one cell unit group, wherein the surface pressure providing walls have a pin insertion portion formed by being indented upward from the bottom surface and the pack case may include a guide pin portion formed protruding from the bottom plate and inserted into the pin insertion portion to guide the surface pressure providing walls to a correct position.

Description

Technology Field

[0001] The present invention relates to a battery pack, and more specifically, to a battery pack configured to allow battery cells to be directly assembled into a pack case by omitting the assembly of conventional battery module units during the assembly of the battery pack. Background Technology

[0002] Secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, not only for their primary advantage of being able to drastically reduce the use of fossil fuels, but also because they do not produce any by-products from energy use.

[0003] Accordingly, the application of secondary batteries to various devices is increasing. For example, they are widely used as energy sources for multifunctional small products such as wireless mobile devices or wearable devices, as well as for electric vehicles and hybrid electric vehicles, which are presented as alternatives to conventional gasoline and diesel vehicles, and for energy storage systems (ESS).

[0004] Generally, the operating voltage of a single secondary battery is approximately 2.5V to 4.5V. Therefore, for electric vehicles or power storage devices requiring high capacity and high output, a battery module is configured by connecting multiple secondary batteries in series and / or parallel and housing them in a module housing, and a battery pack is configured by connecting said battery modules in series and / or parallel, and these are used as energy sources. That is, a conventional battery pack includes battery modules as a sub-concept, and a battery module includes battery cells as a sub-concept. Furthermore, the number of battery cells in a single battery module or the number of battery modules in a single battery pack can be determined in various ways depending on the output or capacity of the battery pack required for the electric vehicle.

[0005] Meanwhile, as an example, the battery modules (2) of the battery pack (1) for an electric vehicle include battery cells (3), a busbar frame (not shown) for electrically connecting the battery cells, and a module housing (4) that integrates the battery cells and the busbar frame. As shown in FIGS. 1 and 2, the battery modules are placed in the internal space (5) of a pack tray and can be fixed to the bottom of the pack tray with bolts or the like. Generally, the pack tray may be equipped with multiple beam frames (6) to increase durability against shock or vibration. The beam frames extend from one side wall of the pack tray and are connected to the other side wall to suppress twisting or deformation of the pack tray. The internal space of the pack tray may be divided into multiple sections by the beam frames, and battery modules may be placed in each of the divided spaces.

[0006] However, it has been pointed out that in the case of battery packs in which battery modules are mounted in a pack tray as described above, factors such as the dead space corresponding to the gap between the battery module and the beam frame, as well as the weight and volume occupied by the module housing, act as elements that reduce the energy density per unit volume of the battery pack, making it difficult to significantly increase the energy capacity of the battery pack. Nevertheless, with the recent rapid growth of the electric vehicle market, the driving range of electric vehicles is becoming increasingly important. The driving range of an electric vehicle is largely dependent on the energy capacity of the battery pack. Therefore, devising a method to increase the energy density per unit volume of the battery pack remains a major issue in the industry. Accordingly, a so-called Cell-to-Pack type battery pack, which eliminates the module housing and mounts battery cells directly into the pack tray—that is, bypassing the battery module manufacturing stage and mounting battery cells directly into the pack tray—is recently gaining attention.

[0007] However, since cell-to-pack systems do not utilize modular housings, battery cells must be mounted and secured within the battery pack in a completely different manner compared to conventional methods. Furthermore, they must be able to restrain the cells to prevent movement even under external shocks or vibrations, and to regulate swelling during charging and discharging. Therefore, there is a demand for cell-to-pack battery packs that can maintain the structural stability of the cells during shocks or vibrations, as well as regulate cell swelling. The problem to be solved

[0008] Accordingly, the technical problem to be solved by the present invention is to provide a battery pack of the CTP type that can easily accommodate battery cells in a pack case and secure structural stability against vibration and shock by restraining the battery cells.

[0009] The technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0010] According to one aspect of the present invention, a battery pack may be provided comprising: a plurality of cell units stacked in one direction; a compression pad attached to one side or both sides of each cell unit; a cell unit group including a pair of surface pressure providing walls that integrally compress the cell units and the compression pads between them; and a pack case accommodating at least one cell unit group, wherein the surface pressure providing walls have a pin insertion portion formed by being indented upward from the bottom surface and the pack case includes a guide pin portion formed protruding from a predetermined position on a bottom plate and inserted into the pin insertion portion to guide the surface pressure providing walls to a correct position.

[0011] The above pack case includes a pack tray having a bottom plate and a plurality of beam frames arranged perpendicularly to the bottom plate to form a wall, and the cell unit group may be configured such that the compression pad is seated in the pack tray in a compressed state, one of the pair of surface pressure providing walls faces one of the two beam frames facing each other, and the other of the pair of surface pressure providing walls faces the other of the two beam frames facing each other.

[0012] The two beam frames facing each other can be configured to support the surface pressure providing walls facing each other, so that a reaction force against the restoring force of the compression pads acts on the surface pressure providing walls.

[0013] The guide pin portion may be provided at a position spaced apart from the beam frame by a predetermined distance and configured parallel to the beam frame.

[0014] The guide pin portion is provided with a width smaller than that of the pin insertion portion and can be configured to move relatively in the width direction within the pin insertion portion.

[0015] The above guide pin portion may be provided with a cross-sectional shape that is narrower at the top and wider at the bottom in a trapezoidal form.

[0016] The above guide pin portion may be configured such that its cross-section is in the shape of an arc, and the surface facing the cell units is perpendicular to the bottom plate.

[0017] The above surface pressure providing wall may include a ball member that is rollably coupled to the lower portion.

[0018] The cell unit group above may be configured such that the compression pad is seated between two beam frames facing each other on the bottom plate while in a compressed state, and the compression state of the compression pad is relieved so that the surface pressure providing wall is pushed or comes into contact with the beam frames.

[0019] The above guide pin portion can be formed integrally with the bottom plate.

[0020] The above pin insertion part may include a cushioning pad attached to the inner surface.

[0021] The cell unit may include a cell stack composed of one 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 the top of the cell stack.

[0022] The above battery cell may be a pouch-type battery cell.

[0023] The above-mentioned bottom plate may include a cooling channel through which a refrigerant can flow.

[0024] According to another aspect of the present invention, an automobile comprising the battery pack described above may be provided. Effects of the invention

[0025] According to the present invention, a battery pack of the Cell-to-Pack type can be provided, which can easily accommodate battery cells in a pack case and secure structural stability against vibration and shock by restraining the battery cells, and can prevent performance degradation of the battery cells by regulating excessive swelling of the battery cells during charging and discharging.

[0026] In addition, the battery pack according to the present invention can have a larger energy capacity than conventional battery packs because the battery cells can be intensively stored in the pack case.

[0027] In addition to the above, the present invention may have various other effects, which are described in each embodiment, or effects that can be easily inferred by those skilled in the art, etc., will be omitted. Brief explanation of the drawing

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a schematic diagram illustrating the configuration of a battery pack according to the prior art. Figure 2 is a schematic cross-sectional view of the battery pack of Figure 1. FIG. 3 is a perspective view schematically illustrating the configuration of a battery pack according to one embodiment of the present invention. FIG. 4 is a perspective view of a cell unit according to one embodiment of the present invention. Figure 5 is an exploded perspective view of the cell unit of Figure 4. FIG. 6 is a schematic diagram illustrating a cell unit group according to one embodiment of the present invention. FIG. 7 is a drawing showing an enlarged view of an area inside a pack tray with a portion of the wall of the pack tray omitted, according to one embodiment of the present invention. FIGS. 8 and 9 are drawings illustrating the process of a cell unit group being housed in a pack case according to one embodiment of the present invention. FIG. 10 is a drawing corresponding to FIG. 9, illustrating a modified example of a guide pin portion according to one embodiment of the present invention. FIG. 11 is a drawing corresponding to FIG. 9, illustrating a modified example of a surface pressure providing wall according to one embodiment of the present invention. FIG. 12 is a schematic drawing illustrating an automobile according to one embodiment of the present invention. Specific details for implementing the invention

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0030] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0031] FIG. 3 is a perspective view schematically illustrating the configuration of a battery pack according to one embodiment of the present invention, FIG. 4 is a perspective view of a cell unit according to one embodiment of the present invention, FIG. 5 is an exploded perspective view of the cell unit of FIG. 4, FIG. 6 is a diagram schematically illustrating a cell unit group according to one embodiment of the present invention, and FIG. 7 is a diagram showing an enlarged view of an area inside a pack tray with a part of the wall of the pack tray omitted according to one embodiment of the present invention.

[0032] Referring to FIG. 3, a battery pack according to one embodiment of the present invention includes a cell unit group (10) and a pack case (20).

[0033] The cell unit group (10) comprises, as illustrated in FIG. 4, cell units (100) stacked in one direction, a compression pad (P1) attached to one side or both sides of the cell units (100), and a pair of surface pressure providing walls (200) that provide surface pressure between the cell units (100) and the compression pads (P1).

[0034] The cell unit (100) may mean an energy storage body comprising one or more stacked battery cells (110) or a cell cover (120) that accommodates the one or more battery cells (110).

[0035] Specifically, referring to FIGS. 5 and 6, the cell unit (100) according to the present embodiment comprises a cell stack composed of one or more stacked pouch-type battery cells (110), and a cell cover (120) that covers the remaining parts of the cell stack, excluding the front side, rear side, and bottom side where the electrode lead (111) is located. In other words, the cell cover (120) can be configured to cover both side parts and the top side of the cell stack along the width direction (±X direction) of the cell stack. Additionally, the cell unit (100) comprises a terminal busbar (131) electrically connected to the electrode lead (111) of the pouch-type battery cells (110), and a busbar frame assembly (130) that supports the terminal busbar (131) and covers the front open end and rear open end of the cell cover (120) which is open. That is, the cell unit (100) of the present embodiment has a busbar frame assembly (130) on the front side and the rear side, respectively. However, unlike the present embodiment, the cell unit (100) may be composed only of a cell stack and a cell cover (120). In this case, a plurality of cell units (100) may be stacked in one direction, and a busbar frame assembly (130) capable of covering the front side and the rear side of the stacked plurality of cell units (100) at once may be used.

[0036] Referring again to FIG. 6, the pouch-type battery cell (110) comprises an electrode assembly, a pouch case that accommodates the electrode assembly, and an electrode lead (111) connected to the electrode assembly and extended outward from the pouch case. The electrode lead (111) comprises a pair of positive lead and negative lead. Here, the positive lead and the negative lead may be provided at both ends of the battery cell (110) along the longitudinal direction (Y direction) of the battery cell (110).

[0037] These pouch-type battery cells (110) can be set up so that their wide side is perpendicular to the ground and can be stacked in a predetermined number in one direction (X direction). For example, as shown in FIG. 6, three pouch-type battery cells (110) can be stacked in one direction (X direction). In this case, the positive lead of each pouch-type battery cell (110) is positioned to face forward (-Y direction) and the negative lead of each pouch-type battery cell (110) is positioned to face backward (+Y direction). In this case, the three pouch-type battery cells (110) can be connected in parallel by welding the electrode leads (111) of the same polarity to terminal busbars (131) located on corresponding sides, and can form a single power bank.

[0038] That is, three pouch-type battery cells (110) are accommodated in a cell cover (120) to maintain a stacked state and can be connected in parallel via a terminal busbar (131) of a busbar frame assembly (130). The terminal busbar (131) can be configured so that its upper end is exposed to the outside of the busbar housing (132), and the upper end of the terminal busbar (131) can function as a positive terminal or a negative terminal of the cell unit (100).

[0039] In this embodiment, the cell unit (100) is configured using three pouch-type battery cells (110), but the cell unit (100) may also be configured using one, two, or four or more pouch-type battery cells (110). 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 then two groups of three pouch-type battery cells (110) connected in parallel may be connected in series to configure the six pouch-type battery cells (110) in a so-called '3P2S' form. In this case, the cell unit (100) may be configured to have its positive terminal and negative terminal in the same direction.

[0040] Meanwhile, the pouch-type battery cell (110) may have a storage portion (R) corresponding to a portion that accommodates an electrode assembly inside a pouch case, and four edge portions (E1 to E4) that surround the storage 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 storage portion (R) in a pouch-type battery cell (110) that is arranged upright as in FIG. 6.

[0041] Here, the above edge portions (E1~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. To elaborate, when housing the electrode assembly, a pouch-type battery cell (110) that applies a method of folding a single laminate film has three sealing portions, and a pouch-type battery cell (110) that applies a method of bonding the edges of two laminate films has four sealing portions. Accordingly, the pouch-type battery cell (110) may have three edge portions (E2, E3, E4 or E1, E3, E4) as sealing portions, or all four edge portions (E1~E4) as sealing portions.

[0042] The cell cover (120) may be configured to cover at least a portion of one or more stacked pouch-type battery cells (110). For example, a cell cover (120) configured to cover one pouch-type battery cell (110) may be manufactured in a form that covers both sides of the upper edge portion (E1) and the storage portion (R) of the said pouch-type battery cell (110). Alternatively, as shown in FIG. 6, the cell cover (120) according to the present embodiment may be manufactured in a form that covers the upper edge portion (E1) of the three pouch-type battery cells (110), one side of the storage portion (R) of the first pouch-type battery cell (110) in the stacking order, and one side of the storage portion (R) of the third pouch-type battery cell (110).

[0043] These cell covers (120) can be made of various materials. In particular, the cell covers (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 maintained more stably, and the pouch-type battery cells (110) can be protected more safely from external impacts. For example, the cell covers (120) may be entirely made of stainless steel (SUS) or an alloy including stainless steel.

[0044] Pouch-type battery cells (110) can be said to be vulnerable to external impact and have low hardness because the pouch case is made of a flexible material. Therefore, it is not easy to store only the pouch-type battery cells (110) inside the pack case (20). Accordingly, a cell cover (120) is used, and the cell cover (120) allows the stacked state and upright state of the pouch-type battery cells (110) to be stably maintained.

[0045] Additionally, the cell cover (120) prevents damage or breakage of the pouch-type battery cells (110) from external impacts, and in particular, when storing the pouch-type battery cells (110) in the pack case (20), the stacked state of the pouch-type battery cells (110) can be maintained stably.

[0046] More specifically, regarding the configuration of the cell cover (120) according to the present embodiment, the cell cover (120) includes an upper cover portion (121), a first side cover portion (122), and a second side cover portion (123), as shown in FIG. 6.

[0047] The upper cover portion (121) may be configured to wrap around the upper edge portion (E1) of the pouch-type battery cell (110) housed inside. The upper cover portion (121) may be configured to be in contact with or spaced apart from the upper edge portion (E1) of the pouch-type battery cell (110).

[0048] The first side cover portion (122) may be configured to extend downward from one corner line along the width direction of the upper cover portion (121). For example, the first side cover portion (122) may be configured to extend downward from the left end of the upper cover portion (121) longer than the storage portion (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 cover one side of the storage portion (R) of the first pouch-type battery cell (110) in FIG. 6.

[0050] The second side cover portion (123) may be configured to extend downward from the other corner line along the width direction of the upper cover portion (121). For example, the second side cover portion (123) may be configured to extend downward from the right end of the upper cover portion (121) longer than the storage portion (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 cover one side of the storage portion (R) of the third pouch-type battery cell (110) in FIG. 6.

[0052] The gap between the first side cover portion (122) and the second side cover portion (123) can be determined within a range where the pouch-type battery cells (110) accommodated inside the cell cover (120) can be compressed.

[0053] According to this cell cover (120) configuration, pouch-type battery cells (110) can be compressed inside the cell cover (120), and the lower edge portions of the pouch-type battery cells (110) are 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 portions of the pouch-type battery cells (110) can come into direct contact with the bottom plate (24) of the pack case (20). In this case, heat exchange between the lower edge portions of the pouch-type battery cells (110) and the bottom plate (24) of the pack case (20) can be carried out more smoothly. Additionally, a thermally conductive adhesive (G), etc., may be applied to the bottom plate (24) of the pack case (20) to increase the heat transfer rate between the lower edge portions of the pouch-type battery cells (110) and the bottom plate (24) of the pack case (20). That is, according to the embodiment in which the lower part of the pouch-type battery cells (110) is not covered using the cell cover (120) as in the present embodiment, 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), and furthermore, cooling of the pouch-type battery cells (110) can be easily and efficiently performed.

[0054] Additionally, the cell cover (120) may be provided with the front side, rear side, and bottom side open. Furthermore, the cell cover (120) of the present embodiment may include a cut-off section (124) provided with both upper ends cut off as shown in FIG. 6. Through this cut-off section (124), as shown in FIG. 5, the busbar frame assembly (130) can be inserted into the cell cover (120), and the upper portion bent from the terminal busbar (131) can be exposed in the upper direction of the cell cover (120). In this way, by configuring the electrode terminal of the cell unit (100) to face upward, the convenience of connecting with other cell units (100) or external devices can be increased.

[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 and 6, the first busbar frame assembly may be positioned at one end (-Y direction) along the longitudinal direction of the cell cover (120), and the second busbar frame assembly may be positioned at the other end (+Y direction) of the cell cover (120). As previously mentioned, in this embodiment, the positive leads of three stacked pouch-type battery cells (110) may be integrally welded to the terminal busbar (131) of the first busbar frame assembly, and the negative leads may be integrally welded to the terminal busbar (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 busbar frame assembly (130) may include, as a main component, a terminal busbar (131), a busbar housing (132), a housing cover (133), and an insulating sheet (134), as shown in FIG. 6.

[0057] The terminal busbar (131) may be made of a metal such as copper, nickel, or aluminum, and the busbar housing (132) may be made of an electrically insulating material such as plastic.

[0058] The busbar housing (132) supports the terminal busbar (131) and can be coupled with the cell cover (120). That is, the busbar housing (132) can be configured to be coupled to the front open end and the rear open end of the cell cover (120), respectively, as shown in FIG. 5. At this time, the busbar housing (132) can be fixedly coupled to the cell cover (120) through various fastening methods such as adhesive, welding, snap-fit, hook-fit, bolting, and rivet fastening.

[0059] This busbar housing (132) may be provided in a box shape with a roughly rectangular structure. The busbar housing (132) may be provided with 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. Accordingly, the electrode lead (111) of the battery cell (110) penetrates the busbar housing (132) through the slit and is drawn out to the outside, and the drawn-out portion can be attached to the terminal busbar (131). Laser welding may be performed when attaching the electrode lead (111) to the terminal busbar (131). The portion where the electrode lead (111) and the terminal busbar (131) are joined may be shielded by a housing cover (133). Additionally, an insulating sheet (134) may be further attached to the outside of the housing cover (133). The above insulating sheet (134) can be formed from a flame-retardant material such as, for example, mica.

[0060] As described above, a cell unit (100) according to one embodiment of the present invention may be configured, and a compression pad (P1) may be attached to one side 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 restored 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] Referring again to FIG. 4, cell units (100) with compression pads (P1) attached are stacked facing each other in one direction (X direction), and a surface pressure providing wall (200) is disposed on the outermost side of the stack of cell units (100) thus stacked. That is, a cell unit group (10) according to one embodiment of the present invention includes a plurality of cell units (100), a buffer pad (P2) disposed between the cell units (100), and a surface pressure providing wall (200) disposed one on each side of the outermost side according to the stacking direction of the cell units (100).

[0062] The above surface pressure providing wall (200) can be described as a component used to secure structural stability against vibration and shock by easily storing stacked cell units (100) as a single unit in a pack case (20) and restraining the cell units (100) so that they do not move after being stored in the pack case (20).

[0063] For example, cell units (100) can be stored one by one without using the above-mentioned pressure-providing wall (200). However, this is not effective, such as when the working time is prolonged. In addition, the pouch-type battery cell (110) has a problem where the storage portion (R) expands during overcharging and discharging, and this acts as a factor in performance degradation. This swelling phenomenon can be suppressed or mitigated by compressing the pouch-type battery cell (110) with appropriate pressure. However, if the cell units (100) are mounted directly into the pack case (20) without any compression device, it is difficult to suppress the swelling of the battery cells (110), and furthermore, the position of the battery cells (110) becomes unstable due to external shock or vibration, so there is a possibility that problems may arise in structural and electrical stability.

[0064] Accordingly, the battery pack according to the present invention is configured such that when a cell unit group (10) is configured to include the pair of surface pressure providing walls (200) and the cell unit group (10) is integrally gripped using a robot arm (not shown) or a gripping jig (not shown) and placed in a pack case (20), the pair of surface pressure providing walls (200) provide uniform surface pressure to the stacked battery cells (110). Below, the components of the present invention for this purpose and their operation will be described in more detail.

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

[0066] The above pack tray (22) includes a bottom plate (24) and a plurality of beam frames (23) arranged perpendicularly to the bottom plate (24) to form a wall. The plurality of beam frames (23) may include an outer beam frame (23a) that forms a wall along the outer perimeter of the bottom plate (24) and an inner beam frame (23b) that partitions the internal space of the pack tray (22) by extending across the bottom plate (24) from the inside of the bottom plate (24).

[0067] Each cell unit group (10) can be placed in the internal space of a pack tray (22) that is enclosed and partitioned by the plurality of beam frames (23). For example, as shown in FIG. 3, each cell unit group (10) can be placed in the internal space of a pack tray (22) enclosed by the outer beam frame (23a) and the inner beam frame (23b) of the pack tray (22). Meanwhile, although the pack tray (22) is configured to accommodate four cell unit groups (10) according to the present embodiment, the pack tray (22) may be configured to accommodate fewer 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 position of the outer beam frame (23a) and the inner beam frame (23b).

[0068] The cell unit group (10) may be seated on the pack tray (22) with the compression pads (P1) in a compressed state, and one of the pair of surface pressure providing walls (200) may face one of the two beam frames (23) facing each other, and the other of the pair of surface pressure providing walls (200) may be seated facing the other of the two beam frames (23) facing each other.

[0069] At this time, the battery pack according to the present invention may be configured such that two beam frames (23) facing each other each support a pair of surface pressure providing walls (200) facing each other, so that a reaction force against the restoring force of the compression pads (P1) acts on the surface pressure providing walls (200).

[0070] This will be explained in detail with reference mainly to FIG. 7 to FIG. 9, together with FIG. 3.

[0071] As illustrated in FIG. 3, the surface pressure providing wall (200) is provided with a pin insertion portion (201) at the bottom. The pin insertion portion (201) can be specified as an empty space formed inside the surface pressure providing wall (200) by being indented upward from the bottom surface of the surface pressure providing wall (200). This pin insertion portion (201) can be provided in a form that extends long along the longitudinal direction of the surface pressure providing wall (200).

[0072] And the pack case (20) may include a guide pin part (25) that is formed to protrude at a predetermined position on the bottom plate (24) and is inserted into the pin insertion part (201) to guide the surface pressure providing wall (200) to the correct position.

[0073] The guide pin portion (25) is formed integrally with the pack tray (22) and can be positioned parallel to the beam frame (23) and corresponding in the vertical direction to the pin insertion portion (201) of the surface pressure providing wall (200) when the cell unit group (10) is seated 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) in each partitioned internal space of the pack tray (22) where each cell unit group (10) is to be seated. In this embodiment, one of the two guide pin portions (25) may be provided at a position spaced apart from the outer beam frame (23a) by a predetermined distance, and the other one may be provided at a position spaced apart from the inner beam frame (23b) by a predetermined distance. Here, the predetermined distance may be determined by considering the thickness of the surface pressure providing wall (200), the degree of compression of the compression pads (P1), etc. However, the predetermined distance 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 (200).

[0075] The guide pin portion (25) may have a length corresponding to the surface pressure providing wall (200), and its cross-section may be provided in a trapezoidal shape that is narrower at the top and wider at the bottom. In this case, during the process of placing the surface pressure providing wall (200) onto the pack tray (22), the guide pin portion (25) can be easily inserted into the pin insertion portion (201) of the surface pressure providing wall (200). At this time, if the pin insertion portion (201) is also in a trapezoidal shape corresponding to the guide pin portion (25), insertion between the pin insertion portion (201) and the guide pin portion (25) can be made more easily.

[0076] Additionally, the guide pin portion (25) may be provided with 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), the guide pin portion (25) can be inserted more easily into the pin insertion portion (201) of the surface pressure providing wall (200), and after the guide pin portion (25) is inserted into the pin insertion portion (201), the guide pin portion (25) can be moved relative to the width direction inside the pin insertion portion (201).

[0077] According to the above configuration, as shown in FIG. 8, the cell unit group (10) is placed on the pack tray (22) in a compressed state using a gripping jig (not shown), and when the compression is released, the surface pressure providing wall (200) can be pushed and moved in the ±X direction as indicated by the arrow in FIG. 9 by the restoring force of the compression pads (P1). That is, the cell unit group (10) according to the present embodiment is placed between two beam frames (23) facing each other on the bottom plate (24) in a state where the compression pads (P1) are compressed, and as the compression state of the compression pads (P1) is relieved, the surface pressure providing wall (200) can be pushed in the direction in which the restoring force of the compression pads (P1) acts or come into contact with the beam frames (23).

[0078] To elaborate, as in the embodiment illustrated in FIG. 8, the cell unit group (10) is equipped with compression pads (P1) so that it can be placed on the bottom plate (24) of the pack tray (22) in a compressed state. At this time, the position of the two guide pin portions (25) on the pack tray (22) and the spacing between them can serve as a measure to determine the degree of compression and the loading position of the cell unit group (10). Furthermore, since there is a gap between the beam frame (23) of the pack tray (22) and the guide pin portion (25), and the width of the guide pin portion (25) is formed to be smaller than the pin insertion portion (201) of the surface pressure providing wall (200), the cell unit group (10) can be placed on the bottom plate (24) of the pack tray (22) without the inner surface of the pin insertion portion (201) of the surface pressure providing wall (200) coming into contact with the guide pin portion (25). After placing the cell unit group (10) in the pack tray (22) in this state, when the compression applied to the cell unit group (10) (with a gripping jig) is released, the restoring force of the compression pads (P1) acts, causing the surface pressure providing wall (200) to be pushed in the opposite direction of the compression direction and move toward the beam frame (23).

[0079] Then, as illustrated 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) may be limited to within the range of the width difference between the guide pin part (25) and the pin insertion part (201). Additionally, a cushioning pad (P2) may be attached to at least one side of the guide pin part (25) and the pin insertion part (201) that face each other. The cushioning pad (P2) mitigates the impact resulting from contact between the guide pin part (25) and the pin insertion part (201) and can be compressed between the inner surfaces of the guide pin part (25) and the pin insertion part (201). Therefore, assembly tolerances that may occur depending on the relative positions between the surface pressure providing wall (200), the beam frame (23), and the guide pin part (25) can be resolved by the compression of the cushioning pad (P2).

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

[0081] Therefore, the reaction force of the above-mentioned surface pressure providing wall (200) acts on the cell units (100), so that the cell units (100) can be firmly held. Thus, each cell unit group (10) mounted on the pack tray (22) can be structurally stable even against external shocks or vibrations. In addition, when the battery cells (110) swell during charging and discharging operations, the expansion of the battery cells (110) can be suppressed or mitigated by the reaction force of the above-mentioned pair of surface pressure providing walls (200).

[0082] Meanwhile, referring again to FIGS. 8 and 9, the bottom plate (24) of the pack tray (22) may be configured to have a cooling channel (26) through which a refrigerant can flow. By applying a thermally conductive adhesive (G) on the bottom plate (24) and configuring the cell units (100) to be placed 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 is a drawing corresponding to FIG. 9, illustrating a modified example of a guide pin portion (25) according to one embodiment of the present invention, and FIG. 11 is a drawing corresponding to FIG. 9, illustrating a modified example of a surface pressure providing wall (200) according to one embodiment of the present invention.

[0084] Next, variations of the present invention will be briefly described with reference to FIGS. 10 and FIGS. 11.

[0085] The same reference numbers as those in the aforementioned embodiments represent the same components. Duplicate descriptions of the same components will be omitted, and the explanation will focus on the differences from the aforementioned embodiments.

[0086] The guide pin portion (25) on the aforementioned pack tray (22) does not necessarily have to be in a trapezoidal shape, as in the aforementioned embodiment. The guide pin portion (25) can be manufactured in various shapes other than a trapezoid. For example, as shown in FIG. 10, the guide pin portion (28) may have a cross-sectional shape in the form of an arc. More specifically, the guide pin portion (28) may have a cross-sectional shape in the form of a fan with an angle of 90 degrees, and the surface facing the cell units (100) may be configured to be perpendicular to the bottom plate (24) of the pack tray (22). Also, the pin insertion portion (201) of the surface pressure providing wall (200) may have an internal space configured in a square shape. In this case, when the surface pressure providing wall (200) is seated, its lower end can slide down along the arc portion of the guide pin part (25), and since the vertical surface of the guide pin part (28) and the inner surface of the pin insertion part (201) face each other in a horizontal direction, the reaction force acting between the guide pin part (28) and the inner surface of the pin insertion part (201) can act more uniformly and stably in the horizontal direction.

[0087] Meanwhile, as illustrated in FIG. 11, the surface pressure providing wall (200) according to the modified example may further include a ball member (202) that is slidably coupled to the lower end. As described above, when the cell unit group (10) is placed on the bottom plate (24) of the pack tray (22) in a compressed state with the compression pads (P1) and the restoring force of the compression pads (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) by the rotation of the ball member (202). The ball member (202) may be equipped with, for example, a ball bearing.

[0088] According to the configuration of the present variation, 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 more reliably supported by the beam frame (23), and the reaction force of the surface pressure providing wall (200) acts on the cell units (100) without loss, thereby restraining the cell units (100) more strongly.

[0089] Meanwhile, the battery pack may further include a control module (30). The control module (30) includes a Battery Management System (BMS) that manages the charging and discharging operations, State of Charge (SOC), State of Health (SOH), etc. of the battery cells (110), and may be mounted in the internal space of the pack case (20). Additionally, the battery pack may further include a switching unit (40). The switching unit (40) may be configured to control the electrical connection between the battery pack and an external circuit. To this end, the switching unit (40) may optionally include a current sensor, a power relay, a fuse, etc.

[0090] The battery pack according to the present invention can be used as a power energy source for a vehicle. That is, the vehicle (V) according to the present invention may include the battery pack according to the present invention as described above, as illustrated in FIG. 12. Here, the vehicle according to the present invention may include a specific vehicle that uses electricity as a driving source, such as an electric vehicle or a hybrid vehicle. In addition, the vehicle according to the present invention may further include various other components included in the vehicle, such as a vehicle body or a motor, in addition to the battery pack according to the present invention.

[0091] In this specification, terms indicating directions such as up, down, left, right, front, and back have been used; however, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0092] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0093] 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: Floor plate 25, 28: Guide pin section 26: Cooling channel 100: Cell unit 110: Battery cell 111: Electrode Lead 120: Cell Cover 121: Upper cover part 122: First side cover part 123: Second side cover part 124: Incision part 130: Busbar 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 P1: Compression pad P2: Cushioning pad G: Thermally conductive adhesive

Claims

Claim 1 A battery pack comprising: a plurality of cell units stacked in one direction; a compression pad attached to one or both sides of each cell unit; a cell unit group including a pair of surface pressure providing walls that press the cell units and the compression pads together; and a pack case accommodating at least one cell unit group, wherein the surface pressure providing walls have a pin insertion portion formed by being indented upward from the bottom surface and the bottom surface of the pack case is formed protruding from the bottom plate and includes a guide pin portion that is inserted into the pin insertion portion and guides the surface pressure providing walls to a correct position, wherein the guide pin portion is provided with a width smaller than that of the pin insertion portion and is configured to be movable relative to the width direction within the pin insertion portion. Claim 2 A battery pack according to claim 1, wherein the pack case comprises a pack tray having a bottom plate and a plurality of beam frames arranged perpendicularly to the bottom plate to form a wall, and the cell unit group is characterized in that the compression pad is seated on the pack tray in a compressed state, one of the pair of surface pressure providing walls faces one of the two beam frames facing each other, and the other of the pair of surface pressure providing walls faces the other of the two beam frames facing each other. Claim 3 A battery pack according to paragraph 2, characterized in that two beam frames facing each other each support the surface pressure providing wall facing each other, so that a reaction force against the restoring force of the compression pad acts on the surface pressure providing wall. Claim 4 A battery pack according to paragraph 2, wherein the guide pin portion is positioned at a predetermined distance from the beam frame and is parallel to the beam frame. Claim 5 delete Claim 6 A battery pack according to claim 1, wherein the guide pin portion is characterized by having a longitudinal cross-section in the shape of a trapezoid that is narrower at the top and wider at the bottom. Claim 7 A battery pack according to claim 1, wherein the guide pin portion is provided with a cross-sectional surface in the shape of an arc, and the surface facing the cell units is perpendicular to the bottom plate. Claim 8 A battery pack according to claim 1, wherein the surface pressure providing wall comprises a ball member that is rollably coupled to the lower portion. Claim 9 A battery pack according to paragraph 2, wherein the cell unit group is configured such that the compression pad is seated between two beam frames facing each other on the bottom plate while in a compressed state, and the compression state of the compression pad is relieved so that the surface pressure providing wall is pushed or comes into contact with the beam frames. Claim 10 A battery pack according to claim 1, wherein the guide pin portion is formed integrally with the bottom plate. Claim 11 In claim 1, the battery pack comprises a pin insertion portion including a cushioning pad attached to an inner surface. Claim 12 A battery pack according to claim 1, wherein the cell unit comprises: a cell stack composed of one 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 the top of the cell stack. Claim 13 A battery pack characterized in that, in Clause 12, the battery cell is a pouch-type battery cell. Claim 14 A battery pack according to claim 1, wherein the bottom plate comprises a cooling channel through which a refrigerant can flow. Claim 15 An automobile characterized by including a battery pack according to any one of claims 1 to 4 and claims 6 to 14.

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