Battery module and battery pack including the same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells, each including an electrode lead, are stacked; a fixing frame having both side portions and a bottom portion covering both side portions and a bottom portion of the battery cell stack; a module frame that houses the battery cell stack and the fixing frame; and an inlet and an outlet for circulating a coolant inside the module frame. The battery cell stack includes a first battery cell stack and a second battery cell stack arranged along a length direction in which electrode leads protrude from the battery cells. The bottom portion of the fixing frame includes a beaded surface, and an adhesive member is provided on the beaded surface to contact the bottom 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.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0024294, filed on February 20, 2024, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] 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, which have improved cooling performance and enhanced fixing force of battery cells to improve vibration and impact resistance of the battery module. [Background technology]

[0003] With technological developments and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. As a result, much research is being conducted into secondary batteries that can meet various requirements.

[0004] Secondary batteries are attracting much attention not only for use in mobile devices such as mobile phones, digital cameras, and laptop computers, but also as an energy source for power plants such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0005] Recently, the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, and there has been an increasing demand for battery packs with medium to large modular structures that assemble battery modules in which multiple secondary batteries are connected in series and / or parallel.

[0006] Meanwhile, when a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a common method is to construct a battery module consisting of at least one battery cell, and then use the at least one battery module to add other components to construct the battery pack.

[0007] Because the battery cells that make up such medium- to large-sized battery modules are composed of rechargeable secondary batteries, such high-power, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat generated from the multiple battery cells can be added together in a small space, causing the temperature to rise rapidly and violently. In other words, a battery module in which multiple battery cells are stacked and a battery pack equipped with such a battery module can produce high power output, but it is difficult to remove the heat generated by the battery cells during charging and discharging. If the heat from the battery cells is not properly dissipated, the battery cells will deteriorate quickly, shortening their lifespan and increasing the risk of explosion or fire.

[0008] Furthermore, battery modules included in vehicle battery packs are often exposed to direct sunlight and may be placed in high-temperature conditions such as in summer or desert regions. In addition, since multiple battery modules are placed close together to increase the vehicle's mileage, flames or heat generated in one battery module can easily spread to adjacent battery modules, ultimately leading to the battery pack itself catching fire or exploding.

[0009] FIG. 1 is an exploded perspective view of a conventional battery pack.

[0010] 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 located above the battery modules 1, and an internal beam 13 that defines the positions within the battery pack 10 where the battery modules 1 are mounted.

[0011] When battery modules 1 are mounted in a battery pack 10, the energy density of the battery pack 10 is reduced by the internal beams 13 that separate the battery modules 1, which has resulted in a problem that a larger number of battery packs 10 must be provided to achieve the required efficiency in a device, etc. Also, the weight of the battery packs 10 limits the number of battery packs 10 that can be mounted in a device. Therefore, while reducing the weight of the battery pack 10, the energy density of the battery pack 10 must be reduced and a larger number of battery modules 1 must be mounted in the battery pack 10.

[0012] FIG. 2 is a cross-sectional view showing the battery module of FIG.

[0013] 2, a conventional battery module 1 includes a battery cell stack 3 including battery cells 2 stacked in a predetermined direction, and a module frame 4 that houses the battery cell stack 3, and the battery cell stack 3 is fixedly positioned on a thermally conductive resin layer 5 that is positioned on the bottom of the module frame 4. In this case, to cool heat generated in the battery cell stack 3, a heat sink 6 that is positioned in the -z-axis direction of FIG. 2 and contacts the bottom of the module frame 4 may be provided.

[0014] However, the heat sink 6 has the disadvantage of not being very efficient at cooling because heat is transferred only through the edges of the battery cells 2 rather than directly contacting the battery cell stack 3. Therefore, an improved cooling method is needed to cool the battery module 1 more effectively. Summary of the Invention [Problem to be solved by the invention]

[0015] An object of the present invention is to provide a battery module and a battery pack including the same, which have improved cooling performance and enhanced fixing force of battery cells to improve vibration and impact resistance of the battery module.

[0016] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0017] A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells, each including an electrode lead, are stacked; a fixing frame having both side portions and a bottom portion covering both side portions and a bottom portion of the battery cell stack; a module frame that houses the battery cell stack and the fixing frame; and an inlet and an outlet for circulating a coolant inside the module frame. The battery cell stack includes a first battery cell stack and a second battery cell stack arranged along a length direction in which electrode leads protrude from the battery cells. The bottom portion of the fixing frame includes a beaded surface, and an adhesive member is provided on the beaded surface to contact the bottom 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.

[0018] The first battery cell stack and the second battery cell stack may be located between the inlet and the outlet.

[0019] The inlet, the first battery cell stack, the second battery cell stack, and the outlet may be sequentially positioned along the length direction that is parallel to one surface of the bottom surface portion of the fixing frame and perpendicular to a direction between the two side surfaces of the fixing frame.

[0020] The bead surface may be a region of the lower surface portion that protrudes in a direction in which the battery cell stack is located, and the region of the lower surface portion of the fixing frame other than the bead surface may be a flow path through which the coolant flows.

[0021] The bead surface pattern may be formed such that 20% to 40% of the area of ​​the lower surface of each battery cell contacts the adhesive member.

[0022] The bead surface may include at least one linear bead surface, and the linear bead surface may have a diagonal region that is diagonally connected to the longitudinal direction at an acute angle.

[0023] The bead surface may include a block-type bead surface.

[0024] The line bead surface may be formed in a plurality of sections, and the block bead surface may be positioned between the line bead surfaces.

[0025] The block-type bead surface may be located between the line-type bead surface and the side surface of the fixing frame.

[0026] 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 located between the first bead and the second bead, a fourth bead located between the first bead and one of the two side portions of the fixing frame that is closest to the first bead, and a fifth bead located between the second bead and one of the two side portions of the fixing frame that is closest to the second bead.

[0027] The third bead may be located at the center of the two side portions of the fixing frame, and the first and second beads may be symmetrical with respect to the third bead.

[0028] The third bead may be located at the center of the two side portions of the fixing frame, and the fourth and fifth beads may be symmetrical with respect to the third bead.

[0029] According to another embodiment of the present invention, there is provided a battery pack including the battery module. [Effects of the Invention]

[0030] According to an embodiment of the present invention, the energy density of the battery pack can be improved by electrically connecting the battery modules, and the upper and lower surfaces of the battery cells can be more effectively cooled, thereby improving cooling efficiency and ensuring the safety of the battery modules and the battery pack.

[0031] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the claims. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is an exploded perspective view of a conventional battery pack. [Figure 2] FIG. 2 is a cross-sectional view showing the battery module of FIG. [Figure 3] 1 is a perspective view showing a battery module according to an embodiment of the present invention; [Figure 4] 2 is a perspective view showing a first battery cell stack, a first bus bar frame assembly, and the like, which are included in a battery module according to an embodiment of the present invention. FIG. [Figure 5] FIG. 2 is an exploded perspective view showing a first battery cell stack, a first bus bar frame assembly, and a flexible printed circuit board. [Figure 6] 1 is a perspective view showing a battery cell stack included in a battery module according to an embodiment of the present invention; [Figure 7] FIG. 7 is an exploded perspective view of FIG. 6 to which a fixing frame is added. [Figure 8] FIG. 8 is a perspective view showing the lower part of FIG. 7 at a different angle. [Figure 9] FIG. 7 is a diagram showing the module being inserted into the frame. [Figure 10]FIG. 10 is a perspective view showing the location of the refrigerant within the battery module. [Figure 11] 1 is a plan view showing a battery module according to an embodiment of the present invention, in which an upper portion of a module frame is omitted; FIG. [Figure 12] FIG. 2 is a perspective view of a fixed frame according to an embodiment of the present invention. [Figure 13] FIG. 13 is a plan view of the fixed frame of FIG. [Figure 14] FIG. 10 is a plan view of a fixed frame according to a comparative example of the present invention. [Figure 15] FIG. 10 is a plan view of a fixing frame according to another embodiment of the present invention. [Figure 16] FIG. 10 is a plan view of a fixing frame according to still another embodiment of the present invention. [Figure 17] FIG. 10 is a plan view of a fixing frame according to still another embodiment of the present invention. [Figure 18] FIG. 10 is a plan view of a fixing frame according to still another embodiment of the present invention. [Figure 19] 1 is an exploded perspective view of a battery pack according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0033] The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0034] In order to clearly explain the present invention, parts not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0035] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0036] Furthermore, when a layer, film, region, plate, or other part is said to be "above" another part, this does not only mean that it is "directly above" that part, but also includes cases where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Furthermore, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being "above" in the opposite direction of gravity.

[0037] Furthermore, throughout the specification, when a part is described as "comprising" a certain element, this does not mean that it can further include other elements, unless otherwise specified.

[0038] Furthermore, throughout the specification, "in a plane" means a view of the subject matter as viewed from above, and "in cross section" means a view of the subject matter as viewed from the side across a vertical cross section.

[0039] FIG. 3 is a perspective view of a battery module 100 according to an embodiment of the present invention. FIG. 4 is a perspective view of a first battery cell stack 120a, a first bus bar frame assembly 180, and a flexible printed circuit board 330, which are components included in the battery module 100 according to an embodiment of the present invention. FIG. 5 is an exploded perspective view of the first battery cell stack 120a, the first bus bar frame assembly 180, and the flexible printed circuit board 330. FIG. 6 is a perspective view of a battery cell stack 120 included in a battery module according to an embodiment of the present invention. FIG. 7 is an exploded perspective view of FIG. 6 with a fixing frame 130 added. FIG. 8 is a perspective view illustrating the configuration of FIG. 7 inserted into a module frame 140. FIG. 10 is a perspective view illustrating the placement of a refrigerant within the battery module 100. FIG. 11 is a plan view of a battery module 100 according to an embodiment of the present invention, with the upper portion of the module frame 140 omitted, as viewed from above.

[0040] 3 to 11, a battery module 100 according to an embodiment of the present invention includes a battery cell stack 120 in which a plurality of battery cells 110, each including an electrode lead 111, are stacked. The battery module 100 includes a fixing frame 130 having both side portions 131 and a bottom portion 132 to cover both side and bottom surfaces of the battery cell stack 120, a module frame 140 in which the battery cell stack 120 and the fixing frame 130 are housed, and an inlet 160 and an outlet 170 for circulating a refrigerant inside the module frame 140.

[0041] First, the battery cell 110 may be a pouch-type battery cell. Such a pouch-type battery cell may be formed by accommodating 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 structure.

[0042] A plurality of such battery cells 110 are configured, and the plurality of battery cells 110 are stacked so as to be electrically connected to each other to form a battery cell stack 120. In particular, as shown in Fig. 4, the plurality of battery cells 110 may be stacked in a direction parallel to the y-axis direction. The direction in which the plurality of battery cells 110 are stacked as described above may be defined as the width direction of the battery cell stack 120.

[0043] The fixing frame 130 may be positioned while covering at least one surface of the battery cell stack 120. The fixing frame 130 may be positioned while covering the lower surface of the battery cell stack 120, more specifically, the fixing frame 130 may be positioned while covering the lower surface and part of the side surface of the battery cell stack 120.

[0044] The module frame 140 may be configured to protect the battery cell stack 120 and the electrical components connected thereto from external physical impacts. The module frame 140 may accommodate the battery cell stack 120 and the electrical components connected thereto in an internal space of the module frame 140.

[0045] The module frame 140 may have various structures. According to this embodiment, the module frame 140 may have a mono-frame structure. Here, the mono-frame may be a metal plate having an integrated upper surface, lower surface, and both side surfaces. The mono-frame may be manufactured by extrusion molding.

[0046] 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. In this case, each frame or plate constituting the U-shaped frame may be manufactured by press molding. Furthermore, the module frame 140 may have a mono-frame or U-shaped frame structure, or an L-shaped frame structure, and may have various structures not described in the above examples.

[0047] The module frame 140 may be provided with front and rear open sides along the length direction (x-axis direction). Here, the length direction may be a direction in which the electrode leads 111 protrude from the battery cells 110, as described below. The length direction may be perpendicular to the width direction of the battery cell stack 120 described above. The length direction may be parallel to the x-axis, and the width direction may be parallel to the y-axis. In this case, the front and rear sides of the battery cell stack 120 may be open and not blocked by the module frame 140. The front and rear sides of the battery cell stack 120 may be blocked by bus bar frame assemblies 180, 190, etc., thereby protecting the front and rear sides of the battery cell stack 120 from external physical impacts, etc.

[0048] 10 and 11 , in the battery module 100 according to this embodiment, the refrigerant may flow into the module frame 140 through the inlet 160 and then be discharged to the outside of the battery module 100 through the outlet 170. In this case, the refrigerant may be a fluid. However, since the refrigerant directly contacts the battery cell stack 120, other electrical components, and the bus bar frame assemblies 180 and 190 within the battery module 100, it must be electrically insulated. Therefore, the refrigerant may be a material having insulating properties. For example, the refrigerant may be insulating oil.

[0049] In the first direction d1 and the second direction d2, which are parallel to the direction in which the battery cells 110 are stacked but opposite each other, 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 of each other based on the direction in which the battery cells 110 are stacked. If the inlet 160 and the outlet 170 are arranged in this manner, the refrigerant can flow throughout the entire internal space of the module frame 140 and evenly cool all of the battery cells 110. If the inlet 160 and the outlet 170 are both positioned at the center of the battery cell stack 120 in the stacking direction of the battery cells 110, the refrigerant will flow only to the center, which has the least flow resistance, and will not flow well to the battery cells 110 located on the outer sides of the battery cell stack 120. This ultimately leads to unbalanced cooling within the battery module 100. Furthermore, if the inlet 160 and the outlet 170 are both positioned offset in either the first direction d1 or the second direction d2, the refrigerant will only flow to some of the outer battery cells 110 adjacent to the offset direction, similarly causing unbalanced cooling within the battery module 100. Therefore, in order to guide the refrigerant to flow evenly to all of the battery cells 110 inside the battery module 100, it is preferable that the inlet 160 and the outlet 170 be positioned on opposite sides of each other in the stacking direction of the battery cells 110, as described above.

[0050] The end plates 300 may be located on the first open side (x-axis direction) and the second open side (-x-axis direction) of the module frame 140. The end plate 300 located on the first open side of the module frame 140 may be the first end plate 310, and the end plate 300 located on the second open side of the module frame 140 may be the second end plate 320. Such end plates 300 may physically protect the battery cell stack 120 and other electrical components from external impacts.

[0051] The inlet 160 may be a hole including a protrusion that protrudes in a direction opposite to the area where the module frame 140 is disposed. The protrusion may be positioned by passing through 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 a direction opposite to the area where the module frame 140 is disposed. The protrusion may be positioned by passing through an outlet opening (not shown) formed in the second end plate 320. However, this structure is merely one example of the inlet and outlet of the present invention, and there is no particular limitation on the shape of the inlet and outlet as long as they can allow the refrigerant to flow into and discharge from the module frame 140.

[0052] Referring again to Figures 4 to 8, 10, and 11, the battery module 100 according to an embodiment of the present invention may further include a first bus bar frame assembly 180 provided on one side of the first battery cell stack 120a and a second bus bar frame assembly 190 provided on one side of the second battery cell stack 120b.

[0053] The bus bar frame assemblies 180 and 190 may be located on the open first side (x-axis direction) and second side (-x-axis direction) of the module frame 140 and may be formed to cover the battery cell stack 120. The bus bar frame assemblies 180 and 190 may electrically connect the battery cells 110 that make up the battery cell stack 120 in series or parallel.

[0054] The battery module 100 according to this embodiment may be formed by electrically connecting a first battery cell stack 120a and a second battery cell stack 120b to each other along the length direction (x-axis direction) of the battery cells 110. Therefore, bus bar frame assemblies 180 and 190 may be positioned between the first battery cell stack 120a and the second battery cell stack 120b. Specifically, the first bus bar frame assembly 180 positioned at the other end of the first battery cell stack 120a and the second bus bar frame assembly 190 positioned at one end of the second battery cell stack 120b may be electrically connected to form the battery module 100 according to this embodiment.

[0055] The bus bar frame assemblies 180, 190 may comprise an electrically insulating material.

[0056] Meanwhile, a flexible printed circuit board 330 may be provided to electrically connect the first bus bar frame assembly 180 and the second bus bar frame assembly 190. The flexible printed circuit board 330 is attached to extend in the length direction of the battery cells 110 and is configured 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 and thermal data of the battery cells 110. In particular, the flexible printed circuit board 330 may be bent at one end toward the bus bar frame assemblies 180 and 190 and electrically connected thereto. As a result, voltage data of each battery cell 110 can be sensed and transmitted to the outside.

[0057] Referring again to Figures 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 length direction, which is the direction in which the electrode leads 111 protrude from the battery cells 110.

[0058] Specifically, the battery module 100 of this embodiment may be configured such that 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 of this embodiment has an immersion cooling structure in which a refrigerant directly cools the battery cells 110 to improve cooling performance. However, the immersion cooling structure requires an inlet 160 and an outlet 170 for each battery module 100, which is disadvantageous in terms of energy density. To compensate for the reduced energy density caused by the immersion cooling structure, the battery module 100 of this embodiment has a long module structure in which at least two battery cell stacks 120a, 120b are arranged in one module frame 140.

[0059] 12 is a perspective view of a stationary frame 130 according to one embodiment of the present invention, and FIG. 13 is a plan view of the stationary frame 130 of FIG.

[0060] 6 to 8, 10, 12, and 13, the fixing frame 130 according to this embodiment includes side portions 131 that respectively cover both side surfaces of the battery cell stack 120 and a bottom portion 132 that covers the bottom surface of the battery cell stack 120.

[0061] The lower surface portion 132 of the fixing frame 130 includes a bead surface 500, and adhesive members 210 that contact the lower ends of the first battery cell stack 120a and the second battery cell stack 120b are provided on the bead surface 500. The first battery cell stack 120a and the second battery cell stack 120b are fixed to the fixing frame 130 by the adhesive members 210.

[0062] The bead surface 500 may be a region of the lower surface portion 132 of the fixing frame 130 that protrudes upward, i.e., in the direction in which the battery cell stack 120 is located. The adhesive material 210 may be applied to the bead surface 500 that protrudes upward.

[0063] The fixing frame 130 is made of a rigid material and serves to protect the battery cell stack 120 from external physical impacts and to firmly fix and support the battery cell stack 120 within the module frame 140 .

[0064] The immersion cooling structure requires an airtight structure that seals the refrigerant to prevent leakage to the outside of the battery module 100. Such an airtight structure is achieved by housing the battery cells 110 in the internal space formed by the module frame 140 and the end plates 300. However, this poses a problem in that the battery cells 110 are not properly fixed inside the module frame 140. Therefore, in this embodiment, a fixing structure using a fixing frame 130 is implemented to fix the battery cells 110 in the immersion cooling structure battery module 100 and maintain a stable stacked structure of the battery cells 110. However, if an adhesive material is provided over the entire lower surface 132 of the fixing frame 130, the lower surface of the battery cell stack 120 may not come into contact with the refrigerant, which could result in reduced cooling performance. Therefore, to fix the battery cells 110 and ensure a certain amount of cooling area under the battery cell stack 120, a protruding bead surface 500 is provided on a portion of the lower surface 132 of the fixing frame 130. That is, in the area where the bead surface 500 is not formed, the coolant comes into direct contact with the lower surface of the battery cell stack 120 and can cool the lower part of the battery cells 110 .

[0065] The adhesive member 210 refers to 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 double-sided tape or a chemical adhesive that bonds through a chemical reaction when attached to the bead surface 500 provided on the lower surface 132 of the fixing frame 130. The adhesive member 210 can maintain the stacked structure of the first battery cell stack 120a and the second battery cell stack 120b.

[0066] In another embodiment, the adhesive member 210 may be an insulating tape. In still another embodiment, the adhesive member 210 may be formed of resin. For example, the adhesive member 210 may be formed of resin. When the adhesive member 210 comes into contact with other components, it hardens and bonds to the other components, thereby fixing and supporting them.

[0067] Therefore, the adhesive strength between the first and second battery cell stacks 120a and 120b and the fixing frame 130 can be stronger. In this case, even if an external impact is applied to the battery module 100, the first and second battery cell stacks 120a and 120b will not separate or detach from the fixing frame 130, thereby improving the safety and mechanical reliability of the battery.

[0068] An adhesive material 210 that contacts the lower end of the battery cell stack 120 is applied to a part or the entire area of ​​the bead surface 500 .

[0069] 10 and 11, the first battery cell stack 120a and the second battery cell stack 120b may be located 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 located sequentially along a length direction that is parallel to one surface of the lower surface portion 132 of the fixing frame 130 and perpendicular to the direction between the two side surfaces 131 of the fixing frame 130.

[0070] When the first battery cell stack 120a and the second battery cell stack 120b are disposed between the inlet 160 and the outlet 170, the refrigerant can maintain a unidirectional flow within the battery module 100. The refrigerant that flows in 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. In other words, the refrigerant can flow throughout the entire space within the module frame 140 to evenly cool all of the battery cells 110.

[0071] The refrigerant directly contacts the battery cell stacks 120 and other electrical components that generate heat within the battery module 100, as well as the bus bar frame assemblies 180 and 190, and transfers heat to them, thereby directly cooling them. Therefore, compared to conventional methods of indirectly cooling the battery module 100 using a heat sink (FIGS. 2 and 6), cooling efficiency can be improved, thereby extending the battery life. Referring again to FIGS. 12 and 13, the bead surface 500 is a region of the lower surface 132 of the fixing frame 130 that protrudes in the direction in which the battery cell stacks 120 are located, and the region of the lower surface 132 of the fixing frame 130 other than the bead surface 500 can be a flow path through which the refrigerant flows.

[0072] The coolant flows through the area of ​​the underside 132 of the fixing frame 130 other than the bead surface 500, allowing the coolant to come into direct contact with the underside of the battery cell stack 120 fixed to the fixing frame 130. This improves the cooling performance for the battery cells 110.

[0073] The pattern of the bead surface 500 may be formed so that 20% to 40% of the area of ​​the lower surface of each battery cell 110 contacts the adhesive member 210 .

[0074] As described above, the area of ​​the underside 132 of the fixing frame 130 other than the bead surface 500 can be a flow path through which the coolant flows. In this case, when 20% to 40% of the area of ​​the underside of the battery cell 110 contacts the adhesive member 210, 60% to 80% of the area of ​​the underside of the battery cell 110 can directly contact the coolant.

[0075] The ratio of the area in contact with the adhesive member 210 to the area of ​​the lower surface of the battery cell 110 may be determined depending on the capacity of the battery cell 110, the size of the battery module 100, etc. By adjusting the ratio of the area in contact with the adhesive member 210 to the area of ​​the lower surface of the battery cell 110, the cooling performance of the battery module 100 can be controlled and designed as intended.

[0076] Referring again to FIG. 13, the bead surface 500 includes at least one linear bead surface 500L, and the linear bead surface 500L may have a diagonal area DA that is diagonally connected to the longitudinal direction at an acute angle.

[0077] The hatched area DA serves to guide the flow of the refrigerant from the inlet 160 to the outlet 170. In addition, by introducing the hatched area DA, the ratio of the area of ​​the bottom surface of the battery cell 110 that comes into contact with the adhesive member 210 can be adjusted.

[0078] Although not shown in FIG. 13, an adhesive material 210 that contacts the lower end of the battery cell stack 120 is applied to a part or the entire area of ​​the bead surface 500 .

[0079] An area of ​​20% to 40% of the bottom surface of the battery cell 110 can be in contact with the bead surface 500, but is not limited to 20% to 40%.

[0080] FIG. 14 is a plan view of a fixed frame 130 according to a comparative example of the present invention.

[0081] 14, when a linear bead surface 500L is applied to the lower surface portion 132 of the fixing frame 130, the lower surfaces of the battery cells 110 that contact the adhesive members 210 provided on the linear bead surface 500L among the various battery cells 110 are attached to the adhesive members 210 over an area of ​​20% to 40%, but not over an entire surface. In this case, the lower surfaces of the battery cells 110 do not come into contact with the refrigerant at all, which reduces the cooling performance for the battery cells 110. The different degrees of cooling for the battery cells 110 result in uneven cooling among the battery cells 110, which may lead to reduced performance of the battery module.

[0082] 13, the linear bead surface 500L has the shaded area DA, which allows adjustment so that each of the battery cells 110 is in contact with the bead surface 500 over an area of ​​20% to 40%. This allows the battery cells 110 to be cooled uniformly, preventing performance degradation of the battery module due to uneven cooling.

[0083] Meanwhile, the bead surface 500 may include block-type bead surfaces 500B in addition to the line-type bead surfaces 500L. The block-type bead surfaces 500B may be located between the line-type bead surfaces 500L.

[0084] The block-type bead surface 500B may be formed in one or more. The line-type bead surface 500 may be formed in one or more. The bead surface 500 may include both the block-type bead surface 500B and the line-type bead surface 500L. By appropriately arranging the line-type bead surface 500L and the block-type bead surface 500B, it is possible to set the area of ​​each of all the battery cells 110 to be in contact with the adhesive member 210 by 20% to 40%. However, in another example, the bead surface 500 may include only one of the block-type bead surface 500B and the line-type bead surface 500L.

[0085] The position and size of the block-type bead surfaces 500B may be determined according to the temperature distribution of the battery cell stack 120 during charging and discharging of the battery cells 110. In particular, the area of ​​the lower surface portion 132 of the fixing frame 130 other than the block-type bead surfaces 500B may be a flow path through which the refrigerant flows, and therefore the position, size, and number of the block-type bead surfaces 500B may be determined according to the shape of the refrigerant flow path.

[0086] More specifically, the bead surface 500 according to this embodiment may include a first bead 510 extending in the longitudinal direction, a second bead 520 extending in the longitudinal direction, a third bead 530 located between the first bead 510 and the second bead 520, a fourth bead 540 located between the first bead 510 and one of the side portions 131 of the fixing frame 130 that is closest to the first bead 510, and the side portion 131, and a fifth bead 550 located between the second bead 520 and one of the side portions 131 of the fixing frame 130 that is closest to the second bead 520.

[0087] All of the examples of the line-type bead surface 500L described in this specification are not necessarily in a straight line, as long as the bead surface 500 is continuous from one end of the fixed frame 130 to the other in the length direction, as shown in Fig. 13. In other words, the line-type bead surface 500L can include the shaded area DA.

[0088] The third bead 530 may be located at the center of both side portions 131 of the fixing frame 130, and the first bead 510 and the second bead 520 may be symmetrical with respect to the third bead 530.

[0089] Meanwhile, although not shown in FIG. 13, an adhesive material 210 that contacts the lower end of the battery cell stack 120 is applied to a part or the entire area of ​​the bead surface 500 .

[0090] FIG. 15 is a plan view of a stationary frame 130 according to another embodiment of the present invention.

[0091] Referring to FIG. 15, as shown in FIG. 15, the line-type bead surface 500L can be divided into one or more branches.

[0092] 15, an adhesive member 210 that contacts 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% to 40% of the lower surface of the battery cell 110 may contact the bead surface 500, but is not limited to 20% to 40%.

[0093] FIG. 16 is a plan view of a stationary frame 130 according to another embodiment of the present invention.

[0094] Referring to FIG. 16, the block-type bead surface 500B can be located between the line-type bead surface 500L and the side portion 131 of the fixed frame 130.

[0095] As shown in Fig. 16, the line-shaped bead surface 500L may be divided into one or more branches. Although not shown in Fig. 16, an adhesive material 210 that contacts 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% to 40% of the lower surface of the battery cell 110 may contact the bead surface 500, but is not limited to 20% to 40%.

[0096] FIG. 17 is a plan view of a stationary frame 130 according to another embodiment of the present invention.

[0097] Referring to FIG. 17, the bead surface 500 according to this embodiment is connected along the length direction, and the entire area of ​​the bead surface 500 may be the hatched section DA.

[0098] FIG. 18 is a plan view of a stationary frame 130 according to another embodiment of the present invention.

[0099] Referring to FIG. 18, the bead surface 500 according to this embodiment may include a first bead 510 extending in the longitudinal direction, a second bead 520 extending in the longitudinal direction, a third bead 530 located between the first bead 510 and the second bead 520, a fourth bead 540 located between the first bead 510 and one of the side portions 131 of the fixing frame 130 that is closest to the first bead 510, and the side portion 131, and a fifth bead 550 located between the second bead 520 and one of the side portions 131 of the fixing frame 130 that is closest to the second bead 520.

[0100] All of the examples of the line-type bead surface 500L described in this specification are not necessarily in a straight line, as long as the bead surface 500 is continuous from one end of the fixed frame 130 to the other in the length direction, as shown in Fig. 18. In other words, the line-type bead surface 500L can include the shaded area DA.

[0101] The third bead 530 may be located in the center based on both side portions 131 of the fixing frame 130, and the first bead 510 and the second bead 520 may be symmetrical based on the third bead 530. In addition, the fourth bead 540 and the fifth bead 550 may be symmetrical based on the third bead 530.

[0102] Although not shown in FIG. 18, an adhesive material 210 that contacts the lower end of the battery cell stack 120 is applied to a part or the entire area of ​​the bead surface 500 .

[0103] FIG. 19 is an exploded perspective view of a battery pack 1000 according to one embodiment of the present invention.

[0104] Referring to FIG. 19, a battery pack 1000 including a battery module 100 is provided according to one embodiment of the present invention.

[0105] A battery pack 1000 according to an 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 located on top of the battery modules 100, and at least one venting portion 2000 provided on a side of the lower pack frame 1100. The lower pack frame 1100 and the upper pack frame 1200 may be joined to each other by welding or the like to seal the interior of the battery pack 1000. High-temperature venting gases 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.

[0106] One or more battery modules according to the above-described embodiments may 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.

[0107] The battery module 100 and the battery pack 1000 can be applied to various devices, specifically, transportation means such as electric bicycles, electric cars, and hybrid vehicles, but are not limited thereto, and can be applied to various devices that can use secondary batteries.

[0108] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are used only for convenience of explanation and may change depending on the position of the object of interest, the position of the observer, etc.

[0109] 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. [Explanation of symbols]

[0110] 100: Battery module 110: Battery cell 120: Battery cell stack 130: Fixed frame 140:Module frame 160: Inlet 170: Outlet 210: Adhesive material 500: Bead surface 500B: Block type bead surface 500L: Line type bead surface

Claims

1. a battery cell stack in which a plurality of battery cells, each including an electrode lead, are stacked; a fixing frame including both side portions and a bottom portion for covering both side surfaces and a bottom surface of the battery cell stack; a module frame that houses the battery cell stack and the fixing frame; an inlet and an outlet for circulating a refrigerant inside the module frame; Including, the battery cell stack includes a first battery cell stack and a second battery cell stack arranged along a length direction in which the electrode leads protrude from the battery cells, the lower surface portion of the fixing frame includes a bead surface, and an adhesive member is provided on the bead surface to contact lower ends of the first battery cell stack and the second battery cell stack; the first battery cell stack and the second battery cell stack are fixed to the fixing frame by the adhesive member.

2. The battery module according to claim 1 , wherein the first battery cell stack and the second battery cell stack are located between the inlet and the outlet.

3. 2. The battery module of claim 1, wherein the inlet, the first battery cell stack, the second battery cell stack, and the outlet are sequentially positioned along the length direction that is parallel to one surface of the bottom surface of the fixing frame and perpendicular to a direction between the two side surfaces of the fixing frame.

4. the bead surface is a region of the lower surface portion that protrudes in a direction in which the battery cell stack is located, The battery module according to claim 1 , wherein an area of ​​the lower surface of the fixing frame other than the bead surface is a flow path through which the coolant flows.

5. The battery module according to claim 1 , wherein the bead surface pattern is formed so that, based on each of the battery cells, 20% to 40% of the area of ​​the lower surface of the battery cell is in contact with the adhesive member.

6. The bead surface includes at least one line-type bead surface, The battery module according to claim 1 , wherein the linear bead surface has a diagonal region that is connected obliquely to the longitudinal direction at an acute angle.

7. The battery module according to claim 6 , wherein the bead surface comprises a block-type bead surface.

8. The line-type bead surface is composed of a plurality of bead surfaces, The battery module according to claim 7 , wherein the block-type bead surface is located between the line-type bead surfaces.

9. The battery module according to claim 7 , wherein the block bead surface is located between the line bead surface and the side surface of the fixing frame.

10. The bead surface is a first bead formed to extend in the longitudinal direction; a second bead formed extending in the longitudinal direction; a third bead located between the first bead and the second bead; a fourth bead located between the first bead and one of both side surface portions of the fixing frame that is closer to the first bead; The battery module according to claim 1 , further comprising: a fifth bead positioned between the second bead and one of both side surface portions of the fixing frame that is closer to the second bead.

11. the third bead is located at the center with respect to the both side surface portions of the fixing frame, The battery module of claim 10 , wherein the first bead and the second bead are symmetrical with respect to the third bead.

12. the third bead is located at the center with respect to the both side surface portions of the fixing frame, The battery module of claim 10 , wherein the fourth bead and the fifth bead are symmetrical with respect to the third bead.

13. A battery pack comprising the battery module according to any one of claims 1 to 12.

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