BATTERY PACKING SYSTEM WITH SURFACE PRESSURE DISTRIBUTION STRUCTURE FOR BATTERY CELLS

Abstract

A battery pack system consists of a base plate, crossbeams, and at least three upward-extending longitudinal beams that divide the surface of the base plate into a grid. Battery modules, containing battery cells, are mounted in the resulting grid-shaped spaces and coupled to support sections at each intersection. Each longitudinal beam includes a surface pressure block positioned between two mounting units, which presses the modules against these mounting units on both sides to secure them.

Description

TECHNICAL AREA The present disclosure relates to a battery pack system with a surface pressure distribution structure for battery cells and in particular to a battery pack system with a surface pressure distribution structure for battery cells which is able to distribute the surface pressure exerted on each battery cell uniformly and thereby provide more space in a battery pack and reduce a swelling phenomenon of each battery cell. BACKGROUND Battery pack systems are widely used in various fields such as electric vehicles, energy storage systems (ESS) and household appliances. Generally, a large number of battery cells are assembled in a stacked structure to form a battery module. However, in order to stably couple battery cells arranged in a specific space with maximum energy density, various types of information such as thermal expansion between the battery cells, vibrations and load must be carefully analyzed and applied during execution. Most battery cells are formed in the form of a thin plate. Furthermore, the battery cells are stacked with their broad, mutually facing surfaces to form a stacked structure. In such a stacked structure, unevenly distributed surface pressure can lead to deformation of the battery cells, deterioration of the electrical properties, or a short circuit between the battery cells. In the course of developing battery pack systems, various attempts have been made to solve the aforementioned problem regarding surface pressure. However, conventional battery pack systems still lack the flexibility to predict and prevent various phenomena that occur between battery cells. Therefore, it is necessary to propose a technology that is capable of solving these problems. SUMMARY It is a task of the present disclosure to solve a conventional problem which is that when a plurality of battery modules are coupled to form a battery pack system, the magnitude and direction of the force exerted on each battery module and each battery cell do not coincide. Another task of the present disclosure is to solve a conventional problem, which consists in the fact that a plurality of battery modules coupled to a battery housing exhibit a large variation in the given conditions depending on their position. Another function of the present disclosure is to solve a conventional problem, which is that the area or width of a space in which the battery modules are placed is difficult to control, although micro-deformation of a large number of battery cells can be caused by swelling. The tasks of the present revelation are not limited to the aforementioned tasks, and other unmentioned tasks of the present revelation will be clearly evident from the following description. A battery pack system according to one embodiment of the present disclosure comprises a battery module, a base plate, a cross member, a longitudinal member, and a support section. The battery module is configured to have a structure in which a plurality of battery cells are stacked. The base plate is a plate-shaped element, and a plurality of battery modules are mounted on a wide top surface of the base plate. A plurality of cross members are provided on the top surface of the base plate, arranged parallel to one another, extending upwards, and dividing the top surface of the base plate. At least three longitudinal members are arranged on the top surface of the base plate in a direction orthogonal to the cross members, extending upwards, and dividing the top surface of the base plate in a grid shape.The battery modules are each coupled to support sections that form a grid-like space created by the intersection of the crossbeams and longitudinal beams. Each longitudinal beam includes a pair of fastening units located at its two lateral edges, with the pair of fastening units exhibiting the highest structural stiffness among the crossbeams and longitudinal beams, and a surface pressure block positioned between the pair of fastening units and configured to press the battery modules received on both sides towards the fastening units located on those sides. In the battery pack system according to the embodiment of the present disclosure, each of the support sections can be a space with a bottom surface formed by at least a part of the top surface of the base plate and surrounded by a pair of parallel crossbeams and a pair of parallel longitudinal beams in a rectangular shape. Alternatively, in the battery pack system according to the embodiment of the present disclosure, the base plate can comprise a connection module provided on one side of the base plate as well as a first and a second side wall section, which are walls arranged parallel to the longitudinal beams and each coupled to both side ends of the base plate. In the battery pack system according to the embodiment of the present disclosure, the surface pressure block can further comprise a guide unit comprising an adhesive surface attached to the top of the base plate in an in contact state, a bearing surface formed flat along the center of an upper end thereof in a longitudinal direction, and a guide surface with a width that gradually decreases from the adhesive surface to the bearing surface, and the surface pressure block can be detachably coupled to the bearing surface of the guide unit. Alternatively, in the battery pack system according to the embodiment of the present disclosure, the surface pressure block can comprise a median plane whose width is equal to or greater than the width of the bearing surface and which is in surface contact with the bearing surface in a longitudinal direction, a pair of entry ends formed on both sides of the median plane such that they extend in the longitudinal direction of the median plane, each of the entry ends having an end that tapers downwards, a pair of internal slopes which are slopes arranged to connect the pair of entry ends to both sides of the median plane, and a pair of external slopes which are slopes formed on the sides of the entry ends opposite the internal slopes. In the battery pack system according to the embodiment of the present disclosure, the surface pressure block can comprise a pair of opposing walls formed on both sides of the median plane in the longitudinal direction of the median plane, wherein the walls extend upwards from the pair of inlet ends, and the surface pressure block, the inlet ends and the opposing walls can be formed in one piece from a material that is subject to low deformation under external load and has high stiffness. Alternatively, in the battery pack system according to the embodiment of the present disclosure, the surface pressure block can comprise at least one reinforcing rib which is arranged to connect the pair of opposing walls in a longitudinal direction, wherein the reinforcing rib is a thin plate-shaped element parallel to the median plane. In the battery pack system according to the embodiment of the present disclosure, each of the opposing walls can include a projection extending outwards from the opposing wall along the position where the reinforcing rib is formed, wherein the opposing wall has the same thickness as the reinforcing rib. Alternatively, in the battery pack system according to the embodiment of the present disclosure, the contact surface can have a plurality of mounting holes formed at predetermined intervals in a longitudinal direction and a plurality of fastening pins each coupled to the mounting holes, wherein each of the fastening pins is made of a material that is subject to large elastic deformation when subjected to an external force, the median plane can comprise a plurality of coupling holes formed at the positions corresponding to the mounting holes formed in the contact surface, and the battery pack system can further comprise a plurality of fastening elements extending vertically in an upward-downward direction through the coupling holes, the fastening pins and the coupling holes to fasten the surface pressure block to the guide unit. In the battery pack system according to the embodiment of the present disclosure, the battery module can comprise a rear support provided on the surface adjacent to the fastening unit or the surface pressure block and arranged between the fastening unit or the surface pressure block and the battery module, and the rear support can comprise an elastic layer made of an elastically deformable material, an inwardly facing surface formed on one surface of the elastic layer and having an adhesive quality, and a lubrication surface formed on the other surface of the elastic layer as a sliding surface. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a perspective view depicting a battery housing in a battery pack system according to an embodiment of the present disclosure; Fig. 2 shows a perspective view depicting a battery module coupled to a support section formed in the battery housing in the battery pack system according to the embodiment of the present disclosure; Fig. 3 shows a sectional view of the battery pack system according to the embodiment of the present disclosure along an XY plane; Fig. 4 shows an enlarged partial view showing a part designated A in Fig. 3; Fig. 5 shows an enlarged partial view showing a central part of Fig. 3; Fig. 6 shows a view showing the shape of one of the longitudinal beams to which a guide unit and a surface pressure block are coupled in the battery pack system according to the embodiment of the present disclosure; Fig.Figure 7 shows a perspective partial view illustrating the structure of the surface pressure block in the battery pack system according to the embodiment of the present disclosure; Figure 8 shows a schematic view illustrating the coupling relationship between the guide unit and the surface pressure block in the battery pack system according to the embodiment of the present disclosure; Figure 9 shows a schematic view illustrating the coupling relationship between a guide unit and a surface pressure block in a battery pack system according to another embodiment of the present disclosure; and Figure 10 shows a view illustrating the cross-sectional structure of one of the longitudinal beams, which is formed as a fastening unit in the battery pack system according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION The embodiments disclosed herein are described in detail below with reference to the accompanying drawings. Identical or similar components are designated with identical or similar reference symbols, and redundant descriptions can be omitted. When a component is described as "connected" or "coupled" with another component, the component may be directly connected or coupled to the other component, or there may be other components in between. On the other hand, if a component is described as "directly connected" or "directly coupled" to another component, this means that there is no other component in between. In this patent specification, the term "comprising" or "comprising or having" indicates the presence of the features, steps, operations or processes, components, parts or combinations thereof described herein, without excluding any of them. A first direction (X-axis direction), a second direction (Y-axis direction) and a third direction (Z-axis direction) described herein are used to describe a fixed shape in a three-dimensional space and are orthogonal to each other. The present disclosure is designed to improve the performance and stability of a battery pack system by stably mounting a battery module 1 with a plurality of battery cells and by uniformly distributing the surface pressure exerted on the battery modules 1 or battery cells. Fig. 1 shows a perspective view depicting a battery housing 10 in a battery pack system according to an embodiment of the present disclosure, and Fig. 2 shows a perspective view depicting a battery module 1 coupled to a support section 20 formed in the battery housing 10 in the battery pack system according to the embodiment of the present disclosure. As shown in Fig. 1 and Fig. 2, a battery pack system with a structure for distributed surface pressure for battery cells according to an embodiment of the present disclosure comprises a battery housing 10 with which a plurality of battery modules 1 can be coupled. The battery housing 10 is arranged such that the battery modules 1 are installed in a predetermined space with high energy density. Accordingly, the battery housing 10 has frequently predefined positions at which the battery modules 1 are coupled. First, battery module 1 comprises a large number of battery cells. The battery cells, each of which generally has a flat, plate-shaped structure, overlap each other so that they are coupled in a stacked structure. The battery cells coupled in the stacked structure thus form a single battery module 1. The multitude of battery modules 1 are coupled at predetermined positions in the battery housing 10. The battery housing 10 comprises a base plate 100, which corresponds to a bottom, a first side wall section 110 and a second side wall section 120, which both form side wall surfaces and are detachably attached to the base plate 100. The first side wall section 110 and the second side wall section 120 may further comprise a first mounting end 112 and / or a second mounting end 122 extending outwards for connection or coupling with an external device, structure or components forming the battery pack system. In addition, depending on requirements, a power line, a data line or data cable, a refrigerant or an air hose can be attached to the side of the battery housing 10 in the +Z-axis direction, which are referred to as a connection module 30 for easier identification. The battery housing 10 has a plurality of support sections 20 formed on an upper part of the base plate 100, i.e. on a top of the base plate 100, in order to distribute the space so efficiently that as many battery modules 1 as possible can be coupled. The support sections 20 are predefined spaces that are formed when a large number of crossbeams 200 and a large number of longitudinal beams 300 are arranged in predefined directions and overlap each other. In the battery pack system according to the embodiment of the present disclosure, the crossbeams 200 are provided in a plurality. The plurality of crossbeams 200 is provided on the top surface of the base plate 100 and is formed along straight lines that are arranged parallel to each other. The plurality of crossbeams 200 is provided, as shown, on the top surface of the base plate 100 parallel to each other. Each of the crossbeams 200 protrudes upwards from the top of the base plate 100 by a predetermined height. The crossbeams 200 can be implemented as walls, partitions or intermediate walls, end jaws or the like, which protrude from the top of the base plate 100, and the crossbeams 200 divide the top of the base plate 100. In the embodiment of the present disclosure, at least three longitudinal beams 300 can be provided. However, the number of longitudinal beams 300 is not limited to three. Depending on the embodiments with which the present disclosure is realized, the number of longitudinal beams 300 provided on the top of the base plate 100 can be 3, 7, 11, 15 or 19. The reason for proposing the number of longitudinal beams 300 as described above is that the efficiency is improved when a surface pressure block 400, which is designed to exert a surface pressure on the battery modules 1 located on both sides in opposite directions, is arranged on a central longitudinal beam 300 arranged in parallel. As will be described later, the longitudinal beam 300 can be divided into a fastening unit 310 and a surface pressure block 400. The fastening unit 310 is a longitudinal beam 300, which is rigidly attached and designed to absorb an external force. The surface pressure block 400, on the other hand, is a longitudinal beam 300 that distributes the surface pressure to the battery modules 1 located on both sides. Therefore, it is preferred that at least three longitudinal beams 300 are provided. The longitudinal beam 300 arranged in the middle is the surface pressure block 400 and the fastening units 310 are arranged on both sides of the surface pressure block 400, which is advantageous in order to distribute the surface pressure exerted on the interior of the battery housing 10 in the battery pack system according to the embodiment of the present disclosure. According to the figures, in the battery pack system according to the embodiment of the present disclosure, the longitudinal beam 300 can be divided into a fastening unit 310 and a surface pressure block 400. For example, with three longitudinal beams 300, a middle one of the three longitudinal beams 300 is provided as a surface pressure block 400. The two longitudinal beams 300, which are arranged parallel on both sides of the surface pressure block 400, are provided as fastening units 310. First, the fastening unit 310, which can be made of a material with high rigidity, is firmly connected or coupled to the base plate 100. The fastening unit 310 must be made of the stiffest material of the surrounding components, such as the multitude of cross members 200 and the multitude of longitudinal members 300 provided in the battery housing 10. The fastening unit 310 can have a fastening surface 312 formed at its upper end, which is formed by a wall extending along an imaginary straight line parallel to the Z-axis and having a predetermined width. Both sidewall surfaces of the fastening unit 310 can be covered with a different material up to a specified thickness to increase strength. The two long, opposing sidewall surfaces of the fastening unit 310 form a load-bearing wall 314. The load-bearing wall 314 is designed to be rigid in order to withstand shear forces. The surface pressure block 400 can be detachably coupled to the top of the base plate 100. In particular, with reference to the figures, a central longitudinal beam 300, which is mounted parallel on the top of the base plate 100, can comprise a guide unit 330 and a surface pressure block 400. The guide unit 330 is attached to a top surface of the base plate 100. The guide unit 330 includes an adhesive surface 336. The adhesive surface 336 is coupled to and in contact with the top surface of the base plate 100 and is formed on a lower surface or underside of the guide unit 330. The adhesive surface 336 has a constant width and extends in a straight direction parallel to the longitudinal beams 300 around them. A central part of the upper end of the guide unit 330 has a bearing surface 332, which is a flat surface formed in a longitudinal direction. The bearing surface 332 is opposite the adhesive surface 336 and is arranged directly above the adhesive surface 336 along the path along which the adhesive surface 336 is formed. The width of the contact surface 332 is smaller than the width of the adhesive surface 336. The width between the two sides of the guide unit 330 gradually decreases from the adhesive surface 336 at its lower end to the support surface 332 at its upper end. That is, both sides of the guide unit 330 are formed as guide surfaces 334 that are inclined inwards and upwards. A pair of entry ends 420, formed at the lower end of the surface pressure block 400, lie against the guide surfaces 334 on both sides of the guide unit 330, and the support surface 332 at the upper end of the guide unit 330 and a median plane 410 at a lower end of the surface pressure block 400 are connected to each other and aligned with each other at a predetermined position. Fig. 3 shows a sectional view of the battery pack system according to the embodiment of the present disclosure along an XY plane, and Fig. 4 shows an enlarged partial view showing a part designated A in Fig. 3. As shown in Figs. 3 and 4, the battery housing 10 comprises a base plate 100, which forms a bottom surface parallel to the XZ plane. The plurality of crossbeams 200 and the plurality of longitudinal beams 300 are arranged in a predetermined shape on a wide top surface of the base plate 100. Referring to Fig. 3, the plurality of crossbeams 200 on the top side of the base plate 100 is formed along a straight path parallel to the X-axis. The multitude of longitudinal beams 300 is formed on the top of the base plate 100 along a straight path parallel to the Z-axis. The battery pack system according to the embodiment of the present disclosure can further comprise a first side wall section 110 and a second side wall section 120, which are side walls formed in a direction parallel to the longitudinal beams 300 along both edges of the base plate 100. The majority of the top surface of the base plate 100 is provided with a multitude of support sections 20, each of which holds a battery module 1. The multitude of support sections 20 is designed to maximize the efficiency of the multiple battery modules 1 and various components, such as a short-circuit module and a cooling module. The battery pack system according to the embodiment of the present disclosure is characterized in that each of the plurality of longitudinal beams 300 is divided into a fastening unit 310 and a surface pressure block 400. Referring to the figures, in the present disclosure, where there are three longitudinal beams 300, one of the longitudinal beams 300 is provided as a surface pressure block 400, and the two longitudinal beams 300, which are arranged on both sides of the surface pressure block 400, are provided as fastening units 310. The support section 20, on which each battery module 1 is attached or mounted, is formed as a space with four sides, surrounded by a pair of parallel longitudinal beams 300 and a pair of parallel transverse beams 200. Each of the support elements 20 has a bottom side formed by part of the top of the base plate 100. The battery housing 10 can be provided with a plurality of support sections 20. In the embodiment of the present disclosure, the support sections 20 are formed by a plurality of spaces arranged in a grid-like pattern on the base plate 100. The battery modules 1 are each included in the support sections 20 to form the battery pack system. As shown, a pair of end plates 600 can be provided within the first side wall section 110 or the second side wall section 120, which are designed to attach or fix the battery module 1 mounted on both sides in the plurality of support sections 20. As shown in Fig. 3 and Fig. 4, the surface pressure block 400 is mounted on the top side of the base plate 100 transversely to its center in the direction of the Z-axis. A pair of parallel fastening units 310 is arranged on both sides of the surface pressure block 400, and the support section 20 is formed between each side of the surface pressure block 400 and the inwardly facing load-bearing wall 314 of each of the fastening units 310, so that the battery module 1 is mounted therein. Each battery module 1 is mounted in a corresponding support section 20, taking into account the direction of the contact surfaces of the battery cells arranged in the stacked structure therein. As shown in Fig. 1, the support section 20 is formed between the surface pressure block 400 and the fastening unit 310, and the battery module 1 is coupled to the support section 20. In this case, the battery module 1 is mounted such that one surface of the battery module 1 faces the supporting wall 314 on one side of the fastening unit 310 with high structural stiffness, and the other surface of the battery module 1 faces the surface pressure block 400 located in the middle. Fig. 5 shows an enlarged partial view showing a central part of Fig. 3, and Fig. 6 shows a view showing the shape of one of the longitudinal beams 300 to which the guide unit 330 and the surface pressure block 400 are coupled in the battery pack system according to the embodiment of the present disclosure. As shown in Fig. 5 and Fig. 6, the battery modules 1 can be coupled with the respective support sections 20 in a pre-assembly process in which a surface of each battery module 1 is lightly pressed against the supporting walls 314 on both sides of the fastening unit 310. While a surface of the battery module 1 can be in direct contact with the supporting wall 314 facing the battery module, in the battery pack system according to the embodiment of the present disclosure, a rear support 500 is arranged between the surface of the battery module 1 and the supporting wall 314. Similarly, the rear support 500 can also be arranged between the surface of the battery module 1 and an opposite wall 430 of the surface pressure block 400. Each of the rear supports 500 is formed such that it corresponds to the area or surface of each of the two opposing side surfaces of each battery module 1, and is formed as a thin support to provide a predetermined damping and force distribution. The rear layer 500 includes an elastic layer 520, which consists of a highly elastic material and forms a middle layer. One surface of the elastic layer 520 can be provided with an inwardly facing surface 510, which is a surface layer with adhesive properties or a high coefficient of friction. Furthermore, the other surface of the elastic layer, i.e., the surface facing the side opposite the inwardly facing surface, can be provided with a lubricating surface that has a low coefficient of friction and is designed to slide easily. When each battery module 1 comes into contact with a structure in the battery housing, the rear support 500 can be positioned between them. The inwardly facing surface 510 of the rear support 500 necessarily rests against the surface of the battery module 1, and the opposite lubricating surface 530 points outwards away from the battery module 1. In addition to the rear support 500, a contact plate 320 can be inserted between a surface of each battery module 1 and the supporting wall 314 of the fastening unit 310 facing it. The contact plate 320 is arranged between the lubrication surface 530 of the rear support 500 and the surface of the supporting wall 314 and is designed in such a way that the force acting in a direction from left to right is not concentrated, but distributed in a planar direction corresponding to the adjacent surfaces. Following the pre-assembly process described above, a post-assembly process can be carried out. The post-assembly process involves inserting the surface pressure block 400 between the battery modules 1, which are placed in the support sections 20 on both sides of the guide unit 330, from top to bottom in the pre-assembled state. The surface pressure block 400 is provided at its lower end with a central plane 410, which represents a downwardly directed surface, and on both sides of the central plane 410 are pointed downwardly projecting entry ends 420. The surface pressure block 400 comprises two opposing walls 430, which are side wall structures extending upwards from the entry ends 420 and forming a long length on both sides of the surface pressure block 400. The surface pressure block 400 can be made from a material with high stiffness and can be available individually. The median plane 410 has a width that is at least equal to or greater than the width of the bearing surface 332 formed on the top of the guide unit 330. A pair of entry ends 420, extending in the direction of the Z-axis, is formed at both corner sections of the median plane 410. Each entry end 420 has a protruding structure, the end of which points downwards. Each of the entry ends 420 can include an internal slope 422 that points inwards towards the median plane 410, and an external slope 424 that is opposite the internal slope 422 and slopes or chamfers outwards from a lower end of the entry end 420, and a pair of opposite walls 430 can be formed as two wall structures extending upwards from the external slopes 424 formed at the entry ends 420. The lower end of the surface pressure block 400, on which the central plane 410 and the entry ends 420 are formed, is inserted in the pre-assembled state between the battery modules 1 located in the support sections 20 on both sides. The pair of opposing walls 430, which are formed on both sides of the surface pressure block 400, presses the adjacent surfaces of the battery modules 1 outwards. The surface pressure block 400 is fitted between the battery modules 1 in an upward-downward direction such that the inner slopes 422 of the entry ends 420 formed at their lowest end rest against the guide surfaces 334 of the guide unit 330. This allows the middle plane 410 and the support surface 332 to be aligned in such a way that the middle plane and the support surface 332 are adjacent to each other within a specified area. The surface pressure block 400 can further comprise reinforcing ribs 440 on a pair of opposing walls 430, which are provided on both sides of the block to exert a surface pressure on the surfaces of the battery modules 1 which are arranged on both sides of the block. The reinforcing rib 440 can be a thin, plate-shaped element formed parallel to the midplane 410. Fig. 7 shows a perspective partial view illustrating the structure of the surface pressure block 400 in the battery pack system according to the embodiment of the present disclosure, Fig. 8 shows a schematic view illustrating the coupling relationship between the guide unit 330 and the surface pressure block 400 in the battery pack system according to the embodiment of the present disclosure, and Fig. 9 shows a schematic view illustrating the coupling relationship between a guide unit 330 and a surface pressure block 400 in a battery pack system according to another embodiment of the present disclosure. As shown, the reinforcing rib 440 is formed in the space between the opposing walls 430 and connects the facing surfaces of the opposing walls 430. A plurality of reinforcing ribs 440 can be arranged horizontally at predetermined vertical intervals. The surface pressure block 400 and the guide unit 330 can be fastened in the state in which the center plane 410 and the bearing surface 332 are in contact with each other by the compressive force of the supporting walls 314 from both sides and a corresponding counterforce. However, a fastening pin 342 and a fastening element 344 can also be provided such that the surface pressure block 400 and the guide unit 330 can be fastened more securely to each other. The bearing surface 332 of the guide unit 330 can have a plurality of fastening holes 340, which are formed at predetermined intervals in the longitudinal direction. The fastening pin 342, which is made of a highly elastic material, can be inserted into any of the fastening holes 340. When part of the lower end of the fastening element 344 is inserted into the fastening hole 340, the fastening pin 342 is elastically deformed to couple the fastening element 344 more securely to the fastening hole 340. A plurality of coupling holes 412, corresponding to the fastening holes 340 formed in the bearing surface 332, are formed in the median plane 410 of the surface pressure block 400. If at least one reinforcing rib 440 is provided on the surface pressure block 400 according to an embodiment of the present disclosure, each of the reinforcing ribs 440 can also have a coupling hole 412 formed directly above the coupling holes 412 formed in the median plane 410. The fastening element 344 can extend vertically downwards through the coupling hole 412 formed in the reinforcing rib 440, and a tool T for fastening the fastening element 344 can be moved in the up-down direction. As shown in Figs. 8 and 9, each of the two opposing walls 430 provided on the surface pressure block 400 can further be provided with a projection extending transversely from an outwardly facing outer surface thereof. The projection can be provided on an outer surface of each of the opposing walls 430 along the position where the reinforcing rib 440 is perpendicularly connected to an inner surface of each of the opposing walls 430, when the reinforcing rib 440 is formed between the pair of opposing walls 430. Fig. 10 shows a view showing the cross-sectional structure of one of the longitudinal beams 300, which is formed as a fastening unit 310 in the battery pack system according to the embodiment of the present disclosure. As shown in Fig. 10, in the battery pack system according to the embodiment of the present disclosure, the fastening unit 310, which is one of the longitudinal beams 300, can have expansion joint holes 412 and 316, which are configured to provide higher resistance to external forces in the transverse direction between the load-bearing walls 314 on both sides. Each of the expansion joint holes 412 and 316 is a passage with a circular cross-section formed in the vertical direction. The tool T or the fasteners can be passed through the expansion joint holes 412 and 316, which, due to their circular cross-section, further increase the structural stiffness of the load-bearing walls 314 on both sides of the fastening unit 310. The present disclosure makes the process of assembling a large number of battery modules into a battery housing more regular and simplified, thereby making the manufacture of a battery pack system faster and easier. The present disclosure causes the plurality of battery modules coupled to the battery housing to exhibit a small deviation under the given conditions, even with different coupling positions. The present disclosure enables a large number of battery modules to be flexibly assembled even when the size or volume of the individual battery modules varies within a tolerance range in a regular insertion and processing process. The present disclosure makes each battery cell, each battery module and each battery pack system more stable and robust by ensuring that the surface pressure exerted on each of the battery modules arranged closely together in a defined space is evenly distributed. The effects of this disclosure are not limited to the aforementioned effects, and other, unmentioned effects of this disclosure will be clearly apparent to a person skilled in the art from the above description. Embodiments of the present disclosure have been described above with reference to the drawings. The described embodiments and the drawings are exemplary, and it is obvious that the present disclosure can be modified in various ways within the scope of the disclosed technical ideas. The described embodiments are to be considered as part of the present disclosure, and the scope of the present disclosure is not limited to the described embodiments. The scope of the present disclosure is to be determined by the technical ideas mentioned in the claims. Even if the described embodiments do not expressly describe the operation, process or effect of a particular design, the operation, process or effect that can be predicted by the design falls within the scope of this disclosure.

Claims

Battery pack system with a surface pressure distribution structure for battery cells, the battery pack system comprising: a battery module 1 having a plurality of battery cells coupled in a stacked structure; a base plate 100, which is a plate-shaped element configured to allow a plurality of battery modules 1 to be mounted on a wide top surface thereof; a plurality of crossbeams 200 provided on the wide top surface of the base plate 100, arranged parallel to one another, extending upwards and configured to subdivide the wide top surface of the base plate 100; at least three longitudinal beams 300 arranged on the wide top surface of the base plate 100 in a direction orthogonal to the plurality of crossbeams 200, extending upwards and configured to subdivide the wide top surface of the base plate 100 in a grid shape;and a plurality of support sections 20, each of which is a grid-like space formed by an intersection of the crossbeams 200 and the longitudinal beams 300, and configured to allow the battery modules 1 to be coupled to them, wherein the at least three longitudinal beams 300 comprise: a pair of fastening units 310 arranged on both lateral circumferences thereof, the pair of fastening units 310 having the highest structural stiffness among the crossbeams 200 and the longitudinal beams 300; and a surface pressure block 400 arranged between the pair of fastening units 310 and configured to press the plurality of battery modules 1 received on both sides in the direction of the fastening units 310 arranged on both sides. Battery pack system according to claim 1, wherein each of the plurality of support sections 20 is a space whose underside is formed by at least a part of the wide top of the base plate 100 and is surrounded by a pair of mutually parallel crossbeams 200 and a pair of mutually parallel longitudinalbeams 300 in a square shape. Battery pack system according to claim 1, wherein the base plate 100 comprises: a connection module 30 provided on one side of the base plate 100; and a first side wall section 110 and a second side wall section 120 arranged parallel to the longitudinal beams 300 and each coupled to both side ends of the base plate 100. Battery pack system according to claim 1, wherein the surface pressure block 400 further comprises: a guide unit 330 having an adhesive surface 336 which is attached to the wide top of the base plate 100 in an abutting state; a support surface 332 which is formed flat along a center of an upper end of the guide unit 330 in a longitudinal direction; and a guide surface 334 with a width which gradually decreases from the adhesive surface 336 to the support surface 332, and the surface pressure block 400 is detachably coupled to the support surface 332 of the guide unit 330. Battery pack system according to claim 4, wherein the surface pressure block 400 further comprises: a median plane 410 having a width equal to or greater than the width of the bearing surface 332, and which is in surface contact with the bearing surface 332 in the longitudinal direction; a pair of entry ends 420 formed on both sides of the median plane 410, such that they extend in the longitudinal direction of the median plane 410, each of the entry ends 420 having an end that projects pointed downwards; a pair of internal chamfers 422 configured to connect the pair of entry ends 420 to both sides of the median plane 410; and a pair of external chamfers 424 formed on sides of the entry ends 420 opposite the internal chamfers 422. Battery pack system according to claim 5, wherein: the surface pressure block 400 further comprises a pair of opposing walls 430 formed on both sides of the central plane 410 in the longitudinal direction of the central plane 410 and extending upwards from the pair of entry ends 420, and the surface pressure block 400, the entry ends 420 and the opposing walls 430 are formed in one piece from a single material. Battery pack system according to claim 6, wherein the surface pressure block 400 further comprises at least one reinforcing rib 440 which is configured to connect the pair of opposing walls 430 in the longitudinal direction, wherein the reinforcing rib 440 is a thin plate-shaped element parallel to the median plane 410. Battery pack system according to claim 7, wherein each of the opposing walls 430 has a projection extending outwards from the opposing wall 430 along a position where the reinforcing rib 440 is formed, wherein the opposing wall 430 has the same thickness as the reinforcing rib 440. Battery pack system according to claim 5, wherein: the support surface 332 comprises: a plurality of fastening holes 340 formed at predetermined intervals in the longitudinal direction; and a plurality of fastening pins 342, each coupled to the coupling holes 340, wherein each of the fastening pins 342 is made of a material that is subject to elastic deformation when subjected to an external force; the median plane 410 comprises a plurality of coupling holes 412 formed at positions corresponding to the fastening holes 340 formed in the support surface 332; and the battery pack system further comprises a plurality of fastening elements 344 extending vertically in an upward-downward direction through the coupling holes 412, the fastening pins 342, and the coupling holes 412 to fasten the surface pressure block 400 to the guide unit 330. Battery pack system according to claim 1, wherein: the battery module 1 has a rear support 500, which is provided on a surface next to the fastening unit 310 or the surface pressure block 400 and is arranged between the fastening unit 310 or the surface pressure block 400 and the battery module 1, and the rear support 500 has: an elastic layer 520 made of an elastically deformable material; an inwardly directed surface 510, which is formed on one surface of the elastic layer 520 and has an adhesive quality; and a lubrication surface 530, which is formed on the other surface of the elastic layer 520 as a sliding surface. Battery pack system with a surface pressure distribution structure for battery cells, the battery pack system comprising: a base plate 100 having a top surface; a plurality of crossbeams 200 provided on the top surface, arranged parallel to each other and extending upwards; a plurality of longitudinal beams 300 arranged on the top surface in a direction orthogonal to the plurality of crossbeams 200 and extending upwards; and a plurality of support sections 20 formed by intersections of the plurality of crossbeams 200 and the plurality of longitudinal beams 300 and arranged to accommodate a plurality of battery modules 1, wherein the plurality of longitudinal beams 300 comprising: a pair of fastening units 310, the pair of fastening units 310 having the highest structural stiffness among the plurality of crossbeams 200 and the plurality of longitudinal beams 300;and a surface pressure block 400, which is arranged and configured between the pair of fastening units 310 to press the plurality of battery modules 1 in the direction of at least one of the pair of fastening units 310. Battery pack system according to claim 11, wherein: each of the plurality of support sections 20 has a bottom surface formed by at least a part of the top surface of the base plate 100, and each of the plurality of support sections 20 is surrounded by two crossbeams 200 from the plurality of crossbeams 200 and two longitudinal beams 300 from the plurality of longitudinal beams 300 to form a square shape. Battery pack system according to claim 11, wherein the base plate 100 further comprises: a connection module 30 provided on one side of the base plate 100; a first side wall section 110; and a second side wall section 120, wherein the first side wall section 110 and the second side wall section 120 are arranged parallel to the plurality of longitudinal beams 300 and are each coupled to both side ends of the base plate 100. Battery pack system according to claim 11, wherein: the surface pressure block 400 comprises: a guide unit 330 having an adhesive surface 336 which is attached to the top of the base plate 100 in an in contact state; a support surface 332 which is formed flat along a center of an upper end of the guide unit 330 in a longitudinal direction 300; and a guide surface 334 with a width which decreases from the adhesive surface 336 to the support surface 332, and the surface pressure block 400 is detachably coupled to the support surface 332 of the guide unit 330. Battery pack system according to claim 14, wherein the surface pressure block 400 further comprises: a median plane 410 having a width equal to or greater than the width of the bearing surface 332, and which is in surface contact with the bearing surface 332 in the longitudinal direction 300; a pair of entry ends 420 formed on both sides of the median plane 410 and extending in the longitudinal direction of the median plane 410, each of the entry ends 420 having an end projecting downwards; a pair of internal chamfers 422 configured to connect the pair of entry ends 420 to both sides of the median plane 410; and a pair of external chamfers 424 formed on the sides of the entry ends 420 opposite the internal chamfers 422.

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