Battery module and battery pack including same

Abstract

A battery module according to an embodiment of the present invention includes: a battery cell stack in which a plurality of battery cells including electrode leads are stacked; a fixed frame including both side surface parts and a bottom surface part so as to cover both side surfaces and the bottom surface of the battery cell stack; a module frame in which the battery cell stack and the fixed frame are accommodated; and an inlet and an outlet for circulating a refrigerant into the module frame. The battery cell stack includes a first battery cell stack and a second battery cell stack, which are arranged in the longitudinal direction in which the electrode leads protrude from the battery cells. The bottom surface part of the fixed frame includes a beaded surface. An adhesive member being in contact with the bottom ends of the first battery cell stack and the second battery cell stack is provided on the beaded surface. The first battery cell stack and the second battery cell stack are fixed to the fixed frame by the adhesive member.

Description

Battery module and battery pack including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0024294, filed February 20, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module and a battery pack including the same, in which cooling performance is improved and the fixing force of battery cells is strengthened, thereby improving the vibration and impact performance of the battery module.

[0004] As technological developments and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. Accordingly, extensive research is being conducted on secondary batteries that can meet diverse needs.

[0005] Secondary batteries are attracting much attention not only as an energy source for mobile devices such as cell phones, digital cameras, and laptops, but also as a power source for power devices such as electric bicycles, electric cars, and hybrid electric vehicles.

[0006] Recently, as the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, the demand for battery packs with medium- to large-sized module structures that assemble battery modules in which a number of secondary batteries are connected in series / parallel is increasing.

[0007] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series / parallel, it is common to configure a battery module composed of at least one battery cell and configure a battery pack by adding other components using at least one battery module.

[0008] The battery cells that make up these medium- to large-sized battery modules are composed of rechargeable secondary batteries. Therefore, these high-output, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat from multiple battery cells accumulates in a small space, which can cause the temperature to rise rapidly and severely. In other words, battery modules with multiple battery cells stacked on top of each other and battery packs equipped with such battery modules can achieve high output, but it is difficult to remove the heat generated from the battery cells during charging and discharging. If the heat dissipation of the battery cells is not properly performed, the deterioration of the battery cells will be accelerated, shortening their lifespan and increasing the risk of explosion or fire.

[0009] Moreover, battery modules included in vehicle battery packs are frequently exposed to direct sunlight and may be subjected to high-temperature conditions, such as summer or desert environments. Furthermore, because multiple battery modules are densely packed together to increase vehicle range, flames or heat generated in one module can easily spread to neighboring modules, ultimately leading to ignition or explosion of the battery pack itself.

[0010] Figure 1 is an exploded perspective view of a conventional battery pack.

[0011] Referring to FIG. 1, a conventional battery pack (10) includes a lower pack frame (11) on which a plurality of battery modules (1) are mounted, an upper pack frame (12) positioned above the battery modules (1), and an internal beam (13) that defines a location where the battery modules (1) are mounted within the battery pack (10).

[0012] In this way, when a battery module (1) is mounted inside a battery pack (10), the energy density of the battery pack (10) is reduced due to the internal beam (13) that partitions between the battery modules (1), so there is a problem that a larger number of battery packs (10) must be equipped to meet the efficiency required in a device, etc. In addition, there is a limit to the number of battery packs (10) that can be equipped in a device due to the weight of the battery pack (10). Therefore, in order to reduce the weight of the battery pack (10) and at the same time reduce the energy density of the battery pack (10), a larger number of battery modules (1) must be mounted inside the battery pack (10).

[0013] Fig. 2 is a cross-sectional view showing the battery module of Fig. 1.

[0014] Referring to FIG. 2, a conventional battery module (1) includes a battery cell stack (3) including battery cells (2) stacked in a preset direction, and a module frame (4) for accommodating the battery cell stack (3), and the battery cell stack (3) is fixedly positioned on a thermally conductive resin layer (5) positioned on the bottom of the module frame (4). In this case, in order to cool the heat generated in the battery cell stack (3), a heat sink (6) positioned in the -z-axis direction of FIG. 2 and in contact with the bottom of the module frame (4) may be provided.

[0015] However, the heat sink (6) does not receive heat by directly contacting the battery cell stack (3), but rather transfers heat only through the edge portion of the battery cell (2), so there is a disadvantage in that the cooling efficiency is not very high. Therefore, an improved cooling method is needed to more effectively cool the battery module (1).

[0016] The problem to be solved by the present invention is to provide a battery module having improved cooling performance and strengthening the fixing force of battery cells, thereby improving vibration and impact performance of the battery module, and a battery pack including the same.

[0017] However, the problems to be solved by the embodiments of the present invention are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0018] According to one embodiment of the present invention, a battery module includes a battery cell stack in which a plurality of battery cells including electrode leads are stacked; a fixing frame including side portions and a lower portion to cover both side surfaces and a lower portion of the battery cell stack; a module frame in which the battery cell stack and the fixing frame are accommodated; and an inlet and an outlet for circulating a coolant into the interior of the module frame. The battery cell stack includes a first battery cell stack and a second battery cell stack arranged along a longitudinal direction in which electrode leads protrude from the battery cells. The lower portion of the fixing frame includes a bead surface, and an adhesive member is provided on the bead surface to be in contact with lower ends of the first battery cell stack and the second battery cell stack, and the first battery cell stack and the second battery cell stack are fixed to the fixing frame by the adhesive member.

[0019] The first battery cell stack and the second battery cell stack may be positioned between the inlet and the outlet.

[0020] The inlet, the first battery cell stack, the second battery cell stack, and the outlet may be positioned sequentially along the longitudinal direction, which is parallel to one surface of the lower surface of the fixed frame and perpendicular to the direction between the two side surfaces of the fixed frame.

[0021] The above bead surface is an area protruding from the lower surface in the direction where the battery cell stack is located, and an area of ​​the lower surface of the fixed frame other than the bead surface may be a flow path through which the coolant flows.

[0022] Based on each of the above battery cells, the pattern of the bead surface can be formed so that an area of ​​20% or more and 40% or less of the lower surface of the battery cell is in contact with the adhesive member.

[0023] The above bead surface may include at least one linear bead surface, and the linear bead surface may have a diagonal region extending obliquely at an acute angle with the longitudinal direction.

[0024] The above bead surface may include a block-shaped bead surface.

[0025] The above line-shaped bead surfaces are composed of multiple pieces, and the block-shaped bead surfaces can be positioned between the line-shaped bead surfaces.

[0026] The above block-shaped bead surface can be located between the above line-shaped bead surface and the side portion of the above fixed frame.

[0027] The bead surface may include a first bead formed to extend in the longitudinal direction; a second bead formed to extend in the longitudinal direction; a third bead positioned between the first bead and the second bead; a fourth bead positioned between a side portion closer to the first bead among the two side portions of the fixed frame and the first bead; and a fifth bead positioned between a side portion closer to the second bead among the two side portions of the fixed frame and the second bead.

[0028] The third bead may be positioned in the center with respect to the two side portions of the fixed frame, and the first bead and the second bead may be symmetrical with respect to the third bead.

[0029] The third bead may be positioned in the center with respect to the two side portions of the fixed frame, and the fourth bead and the fifth bead may be symmetrical with respect to the third bead.

[0030] According to another embodiment of the present invention, a battery pack including the battery module is provided.

[0031] According to embodiments of the present invention, the energy density of a battery pack can be improved by electrically connecting each battery module. Furthermore, by more effectively cooling the upper and lower surfaces of the battery cells, cooling efficiency can be improved, thereby ensuring the safety of the battery module and battery pack.

[0032] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0033] Figure 1 is an exploded perspective view of a conventional battery pack.

[0034] Fig. 2 is a cross-sectional view showing the battery module of Fig. 1.

[0035] Figure 3 is a perspective view showing a battery module according to one embodiment of the present invention.

[0036] FIG. 4 is a perspective view showing a configuration included in a battery module according to one embodiment of the present invention, including a first battery cell stack, a first bus bar frame assembly, etc.

[0037] Figure 5 is an exploded perspective view showing a first battery cell stack, a first busbar frame assembly, and a flexible printed circuit board.

[0038] FIG. 6 is a perspective view showing a battery cell stack included in a battery module according to one embodiment of the present invention.

[0039] Figure 7 is an exploded perspective view of Figure 6 with a fixed frame added.

[0040] Figure 8 is a perspective view showing the lower part of Figure 7 at a different angle.

[0041] Figure 9 is a drawing showing Figure 7 being inserted into a module frame.

[0042] Figure 10 is a perspective view showing that the coolant is located within the battery module.

[0043] FIG. 11 is a plan view from above of a battery module according to one embodiment of the present invention, with the upper portion of the module frame omitted.

[0044] Figure 12 is a perspective view of a fixed frame according to one embodiment of the present invention.

[0045] Fig. 13 is a plan view of the fixed frame of Fig. 12.

[0046] Figure 14 is a plan view of a fixed frame according to a comparative example of the present invention.

[0047] Figure 15 is a plan view of a fixed frame according to another embodiment of the present invention.

[0048] Figure 16 is a plan view of a fixed frame according to another embodiment of the present invention.

[0049] Figure 17 is a plan view of a fixed frame according to another embodiment of the present invention.

[0050]

[0051] Figure 18 is a plan view of a fixed frame according to another embodiment of the present invention.

[0052] Figure 19 is an exploded perspective view of a battery pack according to one embodiment of the present invention.

[0053] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0054] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0055] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0056] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on" or "over" another part, this includes not only cases where it is "directly on" the other part, but also cases where there are other parts in between. Conversely, when we say that a part is "directly on" another part, we mean that there are no other parts in between. Furthermore, saying that a part is "on" or "over" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "over" the reference part in the opposite direction of gravity.

[0057] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0058] Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

[0059] FIG. 3 is a perspective view showing a battery module (100) according to one embodiment of the present invention. FIG. 4 is a perspective view showing a first battery cell stack (120a), a first busbar frame assembly (180), and a flexible printed circuit board (330) as components included in a battery module (100) according to one embodiment of the present invention. FIG. 5 is an exploded perspective view showing the first battery cell stack (120a), the first busbar frame assembly (180), and the flexible printed circuit board (330). FIG. 6 is a perspective view showing a battery cell stack (120) included in a battery module according to one embodiment of the present invention. FIG. 7 is an exploded perspective view showing a fixed frame (130) added to FIG. 6. FIG. 8 is a perspective view showing the lower part of FIG. 7 at a different angle so that it is visible. FIG. 9 is a drawing showing that the component of FIG. 7 is inserted into a module frame (140). Fig. 10 is a perspective view showing that the refrigerant is positioned within the battery module (100). Fig. 11 is a plan view from above showing the battery module (100) according to one embodiment of the present invention, with the upper portion of the module frame (140) omitted.

[0060] Referring to FIGS. 3 to 11, a battery module (100) according to one embodiment of the present invention includes a battery cell stack (120) in which a plurality of battery cells (110) including electrode leads (111) are stacked. The battery module (100) includes a fixed frame (130) including side portions (131) and a lower portion (132) to cover both side surfaces and a lower surface of the battery cell stack (120); a module frame (140) in which the battery cell stack (120) and the fixed frame (130) are accommodated; and an inlet (160) and an outlet (170) for circulating a coolant into the interior of the module frame (140).

[0061] First, the battery cell (110) may be a pouch-shaped battery cell. Such a pouch-shaped battery cell may be formed by housing an electrode assembly in a pouch case made of a laminate sheet including a resin layer and a metal layer, and then heat-sealing the sealing portion of the pouch case. In this case, the battery cell (110) may be formed in a rectangular sheet-shaped structure.

[0062] These battery cells (110) may be configured in multiple units, and the multiple battery cells (110) may be stacked so as to be electrically connected to each other to form a battery cell stack (120). In particular, as illustrated in FIG. 4, the multiple battery cells (110) may be stacked along a direction parallel to the y-axis direction. As described above, the direction in which the multiple battery cells (110) are stacked may be defined as the width direction of the battery cell stack (120).

[0063] The fixed frame (130) can be positioned while covering at least one side of the battery cell stack (120). The fixed frame (130) can be positioned while covering the lower part of the battery cell stack (120), and more specifically, the fixed frame (130) can be positioned while covering the lower side and a portion of the side surface of the battery cell stack (120).

[0064] The module frame (140) may be intended to protect the battery cell stack (120) and electrical components connected thereto from external physical impact. The module frame (140) may accommodate the battery cell stack (120) and electrical components connected thereto in the internal space of the module frame (140).

[0065] The structure of the module frame (140) may vary. According to the present embodiment, the structure of the module frame (140) may be a monoframe structure. Here, the monoframe may be in the form of a metal plate with an upper surface, a lower surface, and both side surfaces integrated. The monoframe may be manufactured by extrusion molding.

[0066] However, the structure of the module frame (140) is not limited thereto, and as another example, the module frame (140) may have a structure in which a U-shaped frame and an upper plate are combined. In this case, the U-shaped frame may be formed by combining or integrating the lower surface and both side surfaces of the module frame (140). At this time, each frame or plate constituting the U-shaped frame may be manufactured by press forming. In addition, the structure of the module frame (140) may be provided as an L-shaped frame structure in addition to a mono-frame or a U-shaped frame, and may also be provided as various structures not described in the above-described examples.

[0067] The module frame (140) may be provided in a form in which the front and back sides are open along the longitudinal direction (x-axis direction). Here, the longitudinal direction may be a direction in which the electrode leads (111) protrude from the battery cells (110), as will be described later. In addition, the longitudinal direction may be a direction perpendicular to the width direction of the battery cell stack (120) described above. The longitudinal direction may be a direction parallel to the x-axis, and the width direction may be a direction parallel to the y-axis. In this case, the front and back sides of the battery cell stack (120) may be open without being covered by the module frame (140). The front and back sides of the battery cell stack (120) may be covered by busbar frame assemblies (180, 190), etc., and through this, the front and back sides of the battery cell stack (120) may be protected from external physical impacts, etc.

[0068] In particular, referring to FIGS. 10 and 11, in the battery module (100) according to the present embodiment, the refrigerant may be introduced into the module frame (140) through the inlet (160) and then discharged to the outside of the battery module (100) through the outlet (170). At this time, the refrigerant may be a fluid. However, since the refrigerant is in direct contact with the battery cell stack (120), other electrical components, and busbar frame assemblies (180, 190) within the battery module (100), it is necessary to be electrically insulated. Therefore, the refrigerant may be a material having insulating properties. For example, the refrigerant may be an insulating oil.

[0069] In the first direction (d1) and the second direction (d2) which are parallel to and opposite to the direction in which the battery cells (110) are stacked, the inlet (160) may be positioned offset in the first direction (d1) from the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked. The outlet (170) may be positioned offset in the second direction (d2) from the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked. That is, it is preferable that the inlet (160) and the outlet (170) are positioned on opposite sides based on the direction in which the battery cells (110) are stacked. The inlet (160) and the outlet (170) must be positioned in this manner so that the coolant can flow throughout the space inside the module frame (140) and evenly cool all the battery cells (110). If the inlet (160) and the outlet (170) are located at the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked, the coolant will only flow to the center where the flow resistance is the lowest, and thus the coolant will not flow well to the battery cells (110) located at the outer portion of the battery cell stack (120). Ultimately, this causes a cooling imbalance inside the battery module (100). In addition, if the inlet (160) and the outlet (170) are located so as to be biased toward only one of the first direction (d1) and the second direction (d2), the coolant will only flow to the battery cells (110) at some outer portions adjacent to the biased direction, and thus a cooling imbalance will also occur inside the battery module (100). Therefore, in order to induce the coolant to flow evenly through all of the battery cells (110) inside the battery module (100), as mentioned above, it is preferable that the inlet (160) and the outlet (170) be located on opposite sides based on the direction in which the battery cells (110) are stacked.

[0070] The end plate (300) can be positioned on the first open side (x-axis direction) and the second side (-x-axis direction) of the module frame (140). The end plate (300) positioned on the first open side of the module frame (140) can be a first end plate (310), and the end plate (300) positioned on the second open side of the module frame (140) can be a second end plate (320). This end plate (300) can physically protect the battery cell stack (120) and other electrical components from external impact.

[0071] The inlet (160) may be a hole including a protrusion that protrudes in the opposite direction from the area where the module frame (140) is arranged. The protrusion may be positioned while penetrating an inlet opening (not shown) formed in the first end plate (310). The outlet (170) may be a hole including a protrusion that protrudes in the opposite direction from the area where the module frame (140) is arranged. The protrusion may be positioned while penetrating an outlet opening (not shown) formed in the second end plate (320). However, this structure is only one example of the inlet and outlet in the present invention, and there is no particular limitation on the shape of the inlet and outlet as long as they can introduce refrigerant into the module frame (140) and discharge refrigerant from the module frame (140).

[0072] Referring again to FIGS. 4 to 8, 10, and 11, a battery module (100) according to one embodiment of the present invention may further include a first busbar frame assembly (180) provided on one side of a first battery cell stack (120a); and a second busbar frame assembly (190) provided on one side of a second battery cell stack (120b).

[0073] Busbar frame assemblies (180, 190) can be formed to cover the battery cell stack (120) by being positioned on the open first side (x-axis direction) and second side (-x-axis direction) of the module frame (140). The busbar frame assemblies (180, 190) can electrically connect the battery cells (110) constituting the battery cell stack (120) in series or in parallel.

[0074] The battery module (100) according to the present embodiment may be formed by electrically connecting a first battery cell stack (120a) and a second battery cell stack (120b) along the longitudinal direction (x-axis direction) of the battery cells (110). To this end, busbar frame assemblies (180, 190) may also be positioned between the first battery cell stack (120a) and the second battery cell stack (120b). Specifically, the first busbar frame assembly (180) located at the other end of the first battery cell stack (120a) and the second busbar frame assembly (190) located at one end of the second battery cell stack (120b) may be electrically connected to form the battery module (100) according to the present embodiment.

[0075] The busbar frame assemblies (180, 190) may comprise an electrically insulating material.

[0076] Meanwhile, a flexible printed circuit board (330) may be provided to electrically connect the first busbar frame assembly (180) and the second busbar frame assembly (190). The flexible printed circuit board (330) is configured to extend in the longitudinal direction of the battery cells (110) and be mounted to sense the battery cells (110). That is, as shown in FIG. 5, the flexible printed circuit board (330) is positioned on the upper surface of the battery cell stack (120) and senses voltage data or thermal data of the battery cells (110). In particular, the flexible printed circuit board (330) may be electrically connected while being bent toward the busbar frame assemblies (180, 190) at one end. Accordingly, the voltage data of each battery cell (110) can be sensed and transmitted to the outside.

[0077] Referring again to FIGS. 6 to 8 and 10, the battery cell stack (120) includes a first battery cell stack (120a) and a second battery cell stack (120b) arranged along the longitudinal direction in which the electrode leads (111) protrude from the battery cells (110).

[0078] Specifically, the battery module (100) of the present embodiment may be one in which one end and the other end of each battery cell stack (120) constituting two conventional battery modules (100) are electrically connected. In other words, the first battery cell stack (120a) and the second battery cell stack (120b) may be electrically coupled. As described above, the battery module (100) according to the present embodiment has a structure in which a coolant directly contacts and cools the battery cells (110) in order to increase cooling performance. However, in the case of such a cooling structure, an inlet (160) and an outlet (170) are required for each battery module (100), which is disadvantageous in terms of energy density. In order to compensate for the factor of reduced energy density due to such a cooling structure, the battery module (100) according to the present embodiment has a long module structure in which at least two battery cell stacks (120a, 120b) are arranged in one module frame (140).

[0079] Fig. 12 is a perspective view of a fixed frame (130) according to one embodiment of the present invention. Fig. 13 is a plan view of the fixed frame (130) of Fig. 12.

[0080]

[0081] Referring to FIGS. 6 to 8, 10, 12, and 13, the fixing member (130) according to the present embodiment includes side members (131) that cover both sides of the battery cell stack (120), and a lower member (132) that covers the lower surface of the battery cell stack (120).

[0082] The lower surface (130b) of the fixed frame (130) includes a bead surface (500), and an adhesive member (210) is provided on the bead surface (500) to be in contact with the lower ends of the first battery cell stack (120a) and the second battery cell stack (120b). The first battery cell stack (120a) and the second battery cell stack (120b) are fixed to the fixed frame (130) by the adhesive member (210).

[0083] The bead surface (500) may be a region in which a portion of the lower surface (130b) of the fixed frame (130) protrudes upward, i.e., in the direction in which the battery cell stack (120) is located. An adhesive material (210) may be applied on the bead surface (500) protruding upward in this manner.

[0084] The fixed frame (130) is formed of a material having rigidity, and can play a role in protecting the battery cell stack (120) from external physical impact and firmly fixing and supporting them within the module frame (140).

[0085] In the case of a structure in which the coolant directly contacts the battery cells (110) to cool them, an airtight structure that seals the coolant so that it does not leak to the outside of the battery module (100) is essential. This airtight structure can be implemented by housing the battery cells (110) in the internal space formed by the module frame (140) and the end plate (300), but in this case, there is a problem in that the battery cells (110) are not properly fixed inside the module frame (140). Accordingly, in the battery module (100) of the cooling structure using the coolant, in order to fix the battery cells (110) and maintain a stable stacked structure of the battery cells (110), a fixing structure using a fixing frame (130) is implemented in the present embodiment. However, if an adhesive member is provided on the entire lower surface (132) of the fixing frame (130), there is a concern that the lower surface of the battery cell stack (120) may not be in contact with the coolant, resulting in a decrease in cooling performance. Accordingly, in order to secure a certain level of cooling area on the lower surface of the battery cell stack (120) while fixing the battery cells (110), a bead surface (500) protruding upward is provided on a portion of the lower surface (130b) of the fixing frame (130). That is, in the area where the bead surface (500) is not formed, the coolant can directly contact the lower surface of the battery cell stack (120) and cool the lower portion of the battery cells (110).

[0086] The adhesive member (210) is a general term for a member having adhesive properties for fixing the battery cells (110). For example, the adhesive member (210) may be a pressure-sensitive adhesive such as a double-sided tape or a chemical adhesive that is bonded by a chemical reaction during adhesion to a bead surface (500) provided on the lower surface (132) of the fixing frame (130). The laminated structure of the first battery cell stack (120a) and the second battery cell stack (120b) can be maintained by the adhesive member (210).

[0087] In another embodiment, the adhesive member (210) may be an insulating tape. In another embodiment, the adhesive members (210) may be formed of a resin. For example, the adhesive members (210) may be formed of resin or the like. When the adhesive members (210) come into contact with other components, they may be hardened and then bonded to the other components to securely support them.

[0088] Accordingly, the adhesive strength between the first battery cell stack (120a) and the second battery cell stack (120b) and the fixed frame (130) can be made more solid. In this case, even if an impact is applied to the battery module (100) from the outside, the first battery cell stack (120a) and the second battery cell stack (120b) do not separate or detach from the fixed frame (130), thereby improving the safety and mechanical reliability of the battery.

[0089] An adhesive material (210) that is in contact with the lower part of the battery cell stack (120) is applied to a part or the entire area of ​​the bead surface (500).

[0090] Meanwhile, referring again to FIGS. 10 and 11, the first battery cell stack (120a) and the second battery cell stack (120b) may be positioned between the inlet (160) and the outlet (170). More specifically, the inlet (160), the first battery cell stack (120a), the second battery cell stack (120b), and the outlet (170) may be positioned sequentially along the longitudinal direction, which is parallel to one surface of the lower surface (132) of the fixed frame (130) and perpendicular to the direction between the two side surfaces (131) of the fixed frame (130).

[0091] The first battery cell stack (120a) and the second battery cell stack (120b) must be arranged between the inlet (160) and the outlet (170) so that the coolant can maintain a one-way flow within the battery module (100). The coolant introduced through the inlet (160) can sequentially pass through the first battery cell stack (120a) and the second battery cell stack (120b) and be discharged through the outlet (170). That is, the coolant can evenly cool all the battery cells (110) by flowing throughout the entire space within the module frame (140).

[0092] The coolant can directly cool the battery cell stack (120) and other electrical components and busbar frame assemblies (180, 190) that generate heat within the battery module (100) by directly contacting them and receiving heat from them. Therefore, compared to indirectly cooling the battery module (100) using a heat sink (FIGS. 2, 6) or the like as in the past, the cooling efficiency can be improved, and thus the lifespan of the battery can be extended. Referring again to FIGS. 12 and 13, the bead surface (500) is an area that protrudes from the lower surface (132) of the fixed frame (130) in the direction where the battery cell stack (120) is located, and an area of ​​the lower surface (132) of the fixed frame (130) other than the bead surface (500) can be a flow path through which the coolant flows.

[0093] By allowing the coolant to flow to an area other than the bead surface (500) of the lower surface (132) of the fixed frame (130), the coolant can directly contact the lower portion of the battery cell stack (120) fixed to the fixed frame (130). Through this, the cooling performance for the battery cell (110) can be improved.

[0094] For each battery cell (110), a pattern of the bead surface (500) can be formed so that an area of ​​20% or more and 40% or less of the lower surface of the battery cell (110) is in contact with the adhesive member (210).

[0095] As described above, the area of ​​the lower surface (132) of the fixed frame (130) other than the bead surface (500) may be a flow path for the coolant. In this case, if an area of ​​20% or more and 40% or less of the lower surface of the battery cell (110) is in contact with the adhesive member (210), an area of ​​60% or more and 80% or less of the lower surface of the battery cell (110) may be in direct contact with the coolant.

[0096] The ratio of the area of ​​the lower surface area of ​​the battery cell (110) that is in contact with the adhesive member (210) can be determined by the capacity of the battery cell (110), the size of the battery module (100), etc. By adjusting the ratio of the area of ​​the lower surface area of ​​the battery cell (110) that is in contact with the adhesive member (210), the cooling performance of the battery module (100) can be managed and designed as intended.

[0097] Referring again to FIG. 13, the bead surface (500) includes at least one line-shaped bead surface (500L), and the line-shaped bead surface (500L) may have a diagonal area (DA) extending obliquely at an acute angle with the longitudinal direction.

[0098] The diagonal area (DA) serves to guide the flow of refrigerant from the inlet (160) to the outlet (170). In addition, by introducing the diagonal area (DA), the ratio of the area of ​​the lower surface of the battery cell (110) that comes into contact with the adhesive member (210) can be controlled.

[0099] Although not shown in Fig. 13, an adhesive member (210) that is in contact with the lower part of the battery cell stack (120) is applied to a part or the entire area of ​​the bead surface (500).

[0100] An area of ​​20% or more and 40% or less of the lower surface of the battery cell (110) may be in contact with the bead surface (500), but is not limited to 20% or more and 40% or less.

[0101] Figure 14 is a plan view of a fixed frame (130) according to a comparative example of the present invention.

[0102] As illustrated in FIG. 14, when a straight line-shaped bead surface (500L) is applied to the lower surface (132) of the fixed frame (130), the lower surface of the battery cell (110) that comes into contact with the adhesive member (210) provided on the line-shaped bead surface (500L) among several battery cells (110) is attached to the adhesive member (210) over the entire surface, not just an area of ​​20% or more and 40% or less. In this case, since the lower surface of the battery cell (110) does not come into contact with the coolant at all, the cooling performance for the battery cell (110) is reduced. Since the cooling degrees for the battery cells (110) are different, this causes uneven cooling between the battery cells (110), which may lead to a deterioration in the performance of the battery module.

[0103] On the other hand, in the case of the present embodiment illustrated in Fig. 13, since the linear bead surface (500L) has a diagonal area (DA), each of the battery cells (110) can be adjusted to contact the bead surface (500) in an area of ​​20% or more and 40% or less. Through this, the battery cells (110) can be cooled evenly, and performance degradation of the battery module due to uneven cooling can be prevented.

[0104] Meanwhile, the bead surface (500) may include a block-shaped bead surface (500B) in addition to a line-shaped bead surface (500L). The block-shaped bead surface (500B) may be located between the line-shaped bead surfaces (500L).

[0105] The block-shaped bead surface (500B) may be composed of one or more. The line-shaped bead surface (500L) may be composed of one or more. The bead surface (500) may include both the block-shaped bead surface (500B) and the line-shaped bead surface (500L). By appropriately arranging the line-shaped bead surface (500L) and the block-shaped bead surface (500B), each of all the battery cells (110) may be set to contact the adhesive member (210) for an area of ​​20% or more and 40% or less. However, as another embodiment, the bead surface (500) may include only one of the block-shaped bead surface (500B) and the line-shaped bead surface (500L).

[0106] The block-shaped bead surface (500B) may be determined in position and size according to the temperature distribution of the battery cell stack (120) during charging / discharging of the battery cell (110). In particular, since an area other than the block-shaped bead surface (500B) among the lower surface (132) of the fixed frame (130) may be a flow path for the coolant, the position, size, and number of the block-shaped bead surfaces (500B) may be determined according to the shape of the coolant flow path, etc.

[0107] More specifically, the bead surface (500) according to the present embodiment may include a first bead (510) formed to extend in the longitudinal direction; a second bead (520) formed to extend in the longitudinal direction; a third bead (530) positioned between the first bead (510) and the second bead (520); a fourth bead (540) positioned between the side portion (131) closer to the first bead (510) among the two side portions (131) of the fixed frame (130) and the first bead (510); and a fifth bead (550) positioned between the side portion (131) closer to the second bead (520) among the two side portions (131) of the fixed frame (130) and the second bead (520).

[0108] All embodiments of the linear bead surface (500L) described in this specification are sufficient if the bead surface (500) extends from one end of the fixed frame (130) to the other end in the longitudinal direction, as illustrated in FIG. 13, and does not always need to be a straight line. That is, the linear bead surface (500L) may include a diagonal area (DA).

[0109] The third bead (530) can be positioned in the center with respect to both side surfaces (131) of the fixed frame (130), and the first bead (510) and the second bead (520) can be symmetrical with respect to the third bead (530).

[0110] Meanwhile, although not shown in Fig. 13, an adhesive member (210) that is in contact with the lower end of the battery cell stack (120) is applied to a part or the entire area of ​​the bead surface (500).

[0111] Figure 15 is a plan view of a fixed frame (130) according to another embodiment of the present invention.

[0112] Referring to FIG. 15, as shown in FIG. 15, the line-shaped bead surface (500L) can be divided into one or more branches.

[0113] Although not shown in Fig. 15, an adhesive member (210) that is in contact with the lower end of the battery cell stack (120) may be applied to a portion or the entire area of ​​the bead surface (500). An area of ​​20% or more and 40% or less of the lower surface of the battery cell (110) may be in contact with the bead surface (500), but is not limited to 20% or more and 40% or less.

[0114] Figure 16 is a plan view of a fixed frame (130) according to another embodiment of the present invention.

[0115] Referring to Fig. 16, the block-shaped bead surface (500B) can be located between the line-shaped bead surface (500L) and the side surface (131) of the fixed frame (130).

[0116] As illustrated in Fig. 16, the linear bead surface (500L) may be divided into one or more branches. Although not illustrated in Fig. 16, an adhesive member (210) that is in contact with the lower end of the battery cell stack (120) is applied to a portion or the entire area of ​​the bead surface (500). An area of ​​20% or more and 40% or less of the lower surface of the battery cell (110) may be in contact with the bead surface (500), but is not limited to 20% or more and 40% or less.

[0117] Figure 17 is a plan view of a fixed frame (130) according to another embodiment of the present invention.

[0118] Referring to FIG. 17, the bead surface (500) according to the present embodiment may extend along the longitudinal direction, but the entire area of ​​the bead surface (500) may be a diagonal section (DA).

[0119] Figure 18 is a plan view of a fixed frame (130) according to another embodiment of the present invention.

[0120] Referring to FIG. 18, the bead surface (500) according to the present embodiment may include a first bead (510) formed to extend in the longitudinal direction; a second bead (520) formed to extend in the longitudinal direction; a third bead (530) positioned between the first bead (510) and the second bead (520); a fourth bead (540) positioned between the side portion (131) closer to the first bead (510) among the two side portions (131) of the fixed frame (130) and the first bead (510); and a fifth bead (550) positioned between the side portion (131) closer to the second bead (520) among the two side portions (131) of the fixed frame (130) and the second bead (520).

[0121] All embodiments of the linear bead surface (500L) described in this specification are sufficient if the bead surface (500) extends from one end of the fixed frame (130) to the other end in the longitudinal direction, as illustrated in FIG. 18, and does not always need to be a straight line. That is, the linear bead surface (500L) may include a diagonal area (DA).

[0122] The third bead (530) may be positioned in the center with respect to both side portions (131) of the fixed frame (130), and the first bead (510) and the second bead (520) may be symmetrical with respect to the third bead (530). In addition, the fourth bead (540) and the fifth bead (550) may be symmetrical with respect to the third bead (530).

[0123] Although not shown in Fig. 18, an adhesive member (210) that is in contact with the lower end of the battery cell stack (120) is applied to a part or the entire area of ​​the bead surface (500).

[0124] Figure 19 is an exploded perspective view of a battery pack (1000) according to one embodiment of the present invention.

[0125] Referring to FIG. 19, according to one embodiment of the present invention, a battery pack (1000) including a battery module (100) is provided.

[0126] A battery pack (1000) according to one embodiment of the present invention may include a lower pack frame (1100) on which a plurality of battery modules (100) are mounted, an upper pack frame (1200) positioned above the battery modules (100), and at least one venting portion (2000) provided on a side surface of the lower pack frame (1100). Here, the lower pack frame (1100) and the upper pack frame (1200) may be joined to each other by a method such as welding, thereby sealing the inside of the battery pack (1000). High-temperature venting gas, etc. discharged from the battery modules (100) in the space between the lower pack frame (1100) and the upper pack frame (1200) may be discharged to the outside through the venting portion (2000).

[0127] One or more battery modules according to the above-described embodiment can be mounted together with various control and protection systems such as a BMS (Battery Management System), a BDU (Battery Disconnect Unit), and a cooling system to form a battery pack.

[0128] The above battery module (100) or battery pack (1000) can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but is not limited thereto, and can be applied to various devices that can use secondary batteries.

[0129] In this example, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0130] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0131] Description of the symbol

[0132] 100: Battery module

[0133] 110: Battery cell

[0134] 120: Battery cell stack

[0135] 130: Fixed frame

[0136] 140: Module Frame

[0137] 160: Inlet

[0138] 170: Outlet

[0139] 210: Adhesive member

[0140] 500: Bead surface

[0141] 500B: Block-shaped bead surface

[0142] 500L: Line-type bead surface

Claims

1. A battery cell stack in which a plurality of battery cells including electrode leads are stacked; A fixed frame including both side portions and a lower portion to cover both side surfaces and the lower portion of the battery cell stack; A module frame in which the battery cell stack and the fixed frame are stored; and Including an inlet and an outlet for circulating refrigerant into the interior of the above module frame; The battery cell stack includes a first battery cell stack and a second battery cell stack arranged along the longitudinal direction in which the electrode leads protrude from the battery cells, The lower portion of the fixed frame includes a bead surface, and an adhesive member is provided on the bead surface to contact the lower ends of the first battery cell stack and the second battery cell stack, A battery module in which the first battery cell stack and the second battery cell stack are fixed to the fixed frame by the adhesive member.

2. In paragraph 1, A battery module in which the first battery cell stack and the second battery cell stack are positioned between the inlet and the outlet.

3. In paragraph 1, A battery module in which the inlet, the first battery cell stack, the second battery cell stack, and the outlet are positioned sequentially along the longitudinal direction, which is parallel to one surface of the lower surface of the fixed frame and perpendicular to the direction between the two side surfaces of the fixed frame.

4. In paragraph 1, The above bead surface is an area protruding from the lower surface in the direction where the battery cell stack is located, A battery module in which the area of ​​the lower surface of the fixed frame other than the bead surface is a flow path through which the coolant flows.

5. In paragraph 1, A battery module in which the pattern of the bead surface is formed so that, based on each of the above battery cells, an area of ​​20% or more and 40% or less of the lower surface of the battery cell is in contact with the adhesive member.

6. In paragraph 1, The above bead surface includes at least one linear bead surface, The above-mentioned line-shaped bead surface is a battery module having a diagonal region extending obliquely at an acute angle with the longitudinal direction.

7. In paragraph 6, The above bead surface is a battery module including a block-shaped bead surface.

8. In paragraph 7, The above line-shaped bead surface is composed of multiple parts, The above block-shaped bead surface is a battery module located between the above line-shaped bead surfaces.

9. In paragraph 7, The above block-shaped bead surface is a battery module located between the line-shaped bead surface and the side portion of the fixed frame.

10. In paragraph 1, The above bead surface is, A first bead formed extending in the longitudinal direction; A second bead formed extending in the longitudinal direction; A third bead positioned between the first bead and the second bead; A fourth bead, located between the side portion closer to the first bead and the first bead among the two side portions of the fixed frame; and A battery module comprising a fifth bead, the fifth bead being positioned between the second bead and the side portion closer to the second bead among the two side portions of the fixed frame.

11. In paragraph 10, The third bead is located in the center of the two side surfaces of the fixed frame, A battery module wherein the first bead and the second bead are symmetrical with respect to the third bead.

12. In paragraph 10, The third bead is located in the center of the two side surfaces of the fixed frame, A battery module wherein the fourth bead and the fifth bead are symmetrical with respect to the third bead.

13. A battery pack including a battery module according to paragraph 1.

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