Battery module and battery pack containing 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 electrode leads, are stacked; a fixing frame including both side portions and a bottom portion so as to cover both side portions and the bottom portion of the battery cell stack; a module frame in which the battery cell stack and the fixing frame are housed; 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 longitudinal direction which is the direction in which the electrode leads protrude from the battery cells. The bottom portion of the fixing frame includes a bead surface, and adhesive members are provided on the bead surface that contact the 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 members.

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 the contents disclosed in the literature of the Korean patent application are included as part of this specification.

[0002] The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module and a battery pack including the same, in which the cooling performance is improved, the fixing force of battery cells is strengthened, and the vibration and shock performance of the battery module is improved.

Background Art

[0003] With the development of technology and the increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. Accordingly, many studies on secondary batteries that can meet various requirements have been conducted.

[0004] Secondary batteries have attracted much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, and notebook computers, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0005] Recently, in addition to the utilization of secondary batteries as an energy storage source, the need for a large - capacity secondary battery structure has increased, and the demand for battery packs with a medium - to - large - module structure in which a number of battery modules in which a number of secondary batteries are connected in series and / or in parallel are assembled has been increasing.

[0006] On the other hand, when a battery pack is configured by connecting a plurality of battery cells in series / parallel, it is common to configure a battery module composed of at least one battery cell and add other components using at least one battery module to configure a battery pack.

[0007] The battery cells that make up such medium- and large-sized battery modules are composed of rechargeable secondary batteries, and such high-power, high-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat from many battery cells can be added together in a confined space, potentially causing the temperature to rise rapidly and drastically. In other words, while high output can be obtained in battery modules with many battery cells stacked on top of each other and in battery packs equipped with such modules, it is not easy 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 more 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 subjected to high-temperature conditions such as summer or desert regions. In addition, because numerous battery modules are densely arranged to increase the vehicle's driving range, flames or heat generated in one battery module can easily spread to neighboring modules, potentially leading to the battery pack itself catching fire or exploding.

[0009] Figure 1 is a disassembled perspective view of a conventional battery pack.

[0010] Referring to Figure 1, a conventional battery pack 10 includes a lower pack frame 11 on which multiple battery modules 1 are mounted, an upper pack frame 12 located above the battery modules 1, and an internal beam 13 that demarcates the positions in which the battery modules 1 are mounted within the battery pack 10.

[0011] Thus, when battery modules 1 are installed inside a battery pack 10, the internal beams 13 that partition the battery modules 1 reduce the energy density of the battery pack 10. Therefore, in order to meet the efficiency requirements of a device, a larger number of battery packs 10 must be installed, which presents a problem. In addition, the weight of the battery pack 10 limits the number of battery packs 10 that can be installed in a device. Consequently, it is necessary to reduce the weight of the battery pack 10 while simultaneously reducing its energy density, so that a larger number of battery modules 1 can be installed inside the battery pack 10.

[0012] Figure 2 is a cross-sectional view showing the battery module of Figure 1.

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

[0014] However, the heatsink 6 does not directly contact the battery cell stack 3 to transfer heat, but rather heat is transferred only through the edges of the battery cells 2, which has the disadvantage of not being very efficient at cooling. Therefore, an improved cooling method is needed to cool the battery module 1 more effectively. [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] The problem that this invention aims to solve is to provide a battery module and a battery pack including the same, in which cooling performance is improved, the fixing force of the battery cells is strengthened, and the vibration and shock performance of the battery module is improved.

[0016] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly extended 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 electrode leads, are stacked; a fixing frame including both side portions and a bottom portion so as to cover both side portions and the bottom portion of the battery cell stack; a module frame in which the battery cell stack and the fixing frame are housed; 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 longitudinal direction which is the direction in which the electrode leads protrude from the battery cells. The bottom portion of the fixing frame includes a bead surface, and adhesive members are provided on the bead surface that contact the 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 members.

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

[0019] The inlet, the first battery cell stack, the second battery cell stack, and the outlet can be sequentially positioned along the longitudinal direction which is parallel to one surface of the lower part of the fixed frame and perpendicular to the direction between the two side surfaces of the fixed frame.

[0020] The bead surface is a region that protrudes from the lower surface in the direction in which the battery cell stack is positioned, and the region of the lower surface of the fixed frame other than the bead surface can be a flow path for the refrigerant.

[0021] Based on each of the battery cells, the pattern of the bead surface can be formed such that a region of 20% or more and 40% or less of the lower surface of the battery cell contacts the adhesive member.

[0022] The bead surface can include at least one line-type bead surface, and the line-type bead surface can have a slanted line region that obliquely connects at an acute angle with the length direction.

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

[0024] The line-type bead surfaces are composed of a plurality, and the block-type bead surface can be located between the line-type bead surfaces.

[0025] The block-type bead surface can be located between the line-type bead surface and the side surface portion of the fixed frame.

[0026] The bead surface can include a first bead formed by extending in the length direction, a second bead formed by extending in the length direction, a third bead located between the first bead and the second bead, a fourth bead located between the side surface portion of the fixed frame closer to the first bead and the first bead among both side surface portions of the fixed frame, and a fifth bead located between the side surface portion of the fixed frame closer to the second bead and the second bead among both side surface portions of the fixed frame.

[0027] The third bead is located at the center with respect to both side surface portions of the fixed frame, and the first bead and the second bead can be symmetric with respect to the third bead.

[0028] The third bead is located at the center with respect to both side surface portions of the fixed frame, and the fourth bead and the fifth bead can be symmetric with respect to the third bead.

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

[0030] According to embodiments of the present invention, the energy density of the 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, the cooling efficiency can be improved, thereby 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 any other effects not mentioned should be clearly understood by those skilled in the art from the claims. [Brief explanation of the drawing]

[0032] [Figure 1] This is a disassembled perspective view of a conventional battery pack. [Figure 2] Figure 1 is a cross-sectional view showing the battery module. [Figure 3] This is a perspective view showing a battery module according to one embodiment of the present invention. [Figure 4] This 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 and a first busbar frame assembly. [Figure 5] This is an exploded perspective view showing the first battery cell stack, the first busbar frame assembly, and the flexible printed circuit board. [Figure 6] This is a perspective view showing a battery cell stack included in a battery module according to one embodiment of the present invention. [Figure 7] Figure 6 is an exploded perspective view with a fixed frame added. [Figure 8] This is a perspective view showing the lower part of Figure 7 from a different angle. [Figure 9] Figure 7 is a diagram showing how it is inserted into the module frame. [Figure 10]This is a perspective view showing the location of the refrigerant inside the battery module. [Figure 11] This is a top view of a battery module according to one embodiment of the present invention, in which the upper part of the module frame is omitted. [Figure 12] This is a perspective view of a fixed frame according to one embodiment of the present invention. [Figure 13] Figure 12 is a plan view of the fixed frame. [Figure 14] This is a plan view of a fixed frame according to an comparative example of the present invention. [Figure 15] This is a plan view of a fixed frame according to another embodiment of the present invention. [Figure 16] This is a plan view of a fixed frame according to yet another embodiment of the present invention. [Figure 17] This is a plan view of a fixed frame according to yet another embodiment of the present invention. [Figure 18] This is a plan view of a fixed frame according to yet another embodiment of the present invention. [Figure 19] This is an exploded perspective view of a battery pack according to one embodiment of the present invention. [Modes for carrying out the invention]

[0033] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be realized in a variety of different forms and is not limited to the embodiments described herein.

[0034] To clearly explain the present invention, descriptive parts that are unnecessary have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0035] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for the sake of explanation, and therefore the present invention is not necessarily limited to those shown. In the drawings, the thicknesses are shown enlarged to clearly represent various layers and regions. Also, in the drawings, the thicknesses of some layers and regions are shown in an exaggerated manner for the sake of explanation.

[0036] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on top" of another part, this includes not only the case where it is "directly above" the other part, but also the case where the other part is in between. Conversely, when we say that one part is "directly above" another part, it means that there is no other part in between. Also, being "on top" of a reference part means being located above or below the reference part, and does not necessarily mean being located "up" in the opposite direction of gravity.

[0037] Furthermore, when a specification states that a part of it "includes" a certain component, unless otherwise specified, this means that it can further encompass other components rather than excluding them.

[0038] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0039] Figure 3 is a perspective view showing a battery module 100 according to one embodiment of the present invention. Figure 4 is a perspective view showing the components included in the battery module 100 according to one embodiment of the present invention, namely the first battery cell stack 120a, the first busbar frame assembly 180, and the flexible printed circuit board 330. Figure 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. Figure 6 is a perspective view showing the battery cell stack 120 included in the battery module according to one embodiment of the present invention. Figure 7 is an exploded perspective view in which the fixed frame 130 is added to Figure 6. Figure 8 is a perspective view shown at a different angle so that the lower part of Figure 7 is visible. Figure 9 is a drawing showing that the components of Figure 7 are inserted into the module frame 140. Figure 10 is a perspective view showing that the refrigerant is located inside the battery module 100. Figure 11 is a top view of the battery module 100 according to one embodiment of the present invention, in which the upper part of the module frame 140 is omitted.

[0040] Referring to Figures 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, each including an electrode lead 111, are stacked. The battery module 100 includes a fixed frame 130, which includes side portions 131 and a bottom portion 132 to cover both sides and the bottom of the battery cell stack 120; a module frame 140 in which the battery cell stack 120 and the fixed frame 130 are housed; and an inlet 160 and an outlet 170 for circulating a coolant inside the module frame 140.

[0041] First, the battery cell 110 can be a pouch-type battery cell. Such a pouch-type battery cell can be formed by housing an electrode assembly in a pouch case made of a laminate sheet containing a resin layer and a metal layer, and then heat-sealing the pouch case. In this case, the battery cell 110 can be formed in a rectangular sheet-type structure.

[0042] Such a battery cell 110 is composed of multiple cells, and multiple 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 Figure 4, multiple battery cells 110 can be stacked along a direction parallel to the y-axis direction. The direction in which multiple battery cells 110 are stacked as described above can be defined as the width direction of the battery cell stack 120.

[0043] The fixed frame 130 can be positioned while covering at least one surface 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 surface and part of the side surface of the battery cell stack 120.

[0044] The module frame 140 can be used to protect the battery cell stack 120 and the electrical components connected thereto from external physical shocks. The module frame 140 can house the battery cell stack 120 and the electrical components connected thereto within its internal space.

[0045] The structure of the module frame 140 can be diverse. According to this embodiment, the structure of the module frame 140 can be a monoframe structure. Here, the monoframe can be in the form of a metal plate material in which the top surface, bottom surface and both sides are integrated. The monoframe can be manufactured by extrusion molding.

[0046] However, the structure of the module frame 140 is not limited to this. As another example, the module frame 140 can have a structure in which a U-shaped frame and an upper plate are joined together. In this case, the U-shaped frame can be formed by joining or integrating the bottom surface and both sides of the module frame 140. At this time, each frame or plate constituting the U-shaped frame can be manufactured by press molding. Furthermore, the structure of the module frame 140 may be provided as an L-shaped frame structure in addition to a monoframe or U-shaped frame, and may be provided in a variety of structures not described in the examples above.

[0047] The module frame 140 can be provided in a configuration in which the front and rear surfaces are open along the longitudinal direction (x-axis direction). Here, the longitudinal direction can be the direction in which the electrode leads 111 protrude from the battery cell 110, as will be described later. The longitudinal direction can also be perpendicular to the width direction of the battery cell stack 120 described earlier. The longitudinal 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 surfaces of the battery cell stack 120 can be left open without being obstructed by the module frame 140. The front and rear surfaces of the battery cell stack 120 can be obstructed by busbar frame assemblies 180, 190, etc., thereby protecting the front and rear surfaces of the battery cell stack 120 from external physical shocks, etc.

[0048] Referring particularly to Figures 10 and 11, in the battery module 100 according to this embodiment, the refrigerant can 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. At this time, the refrigerant can be a fluid. However, since the refrigerant comes into direct contact with the battery cell stack 120, other electrical components, and busbar frame assemblies 180, 190, etc., within the battery module 100, it needs to be electrically insulated. Therefore, the refrigerant can be an insulating material. As an example, the refrigerant can be insulating oil.

[0049] In a first direction d1 and a second direction d2, which are parallel to the direction in which the battery cells 110 are stacked but opposite to each other, the inlet 160 can 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 can 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. In other words, it is preferable that the inlet 160 and the outlet 170 are located on opposite sides of each other with respect to the direction in which the battery cells 110 are stacked. With the inlet 160 and the outlet 170 arranged in this way, the coolant can flow throughout the entire space inside the module frame 140 and cool all the battery cells 110 evenly. If both the inlet 160 and the outlet 170 are located in the center of the battery cell stack 120 in the direction in which the battery cells 110 are stacked, the refrigerant will flow only to the central part, which has the least flow resistance, and therefore the battery cells 110 located on the outer part of the battery cell stack 120 will not receive sufficient refrigerant flow. Ultimately, this leads to a cooling imbalance inside the battery module 100. Similarly, if both the inlet 160 and the outlet 170 are located biased towards either the first direction d1 or the second direction d2, the refrigerant will flow only to some of the outer battery cells 110 adjacent to the biased direction, causing a cooling imbalance inside the battery module 100. Therefore, in order to guide the refrigerant to flow evenly to all the battery cells 110 inside the battery module 100, it is preferable, as described above, that the inlet 160 and the outlet 170 are located on opposite sides of each other with respect to the direction in which the battery cells 110 are stacked.

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

[0051] The inlet 160 may be a hole including a projection that protrudes in the opposite direction to the area where the module frame 140 is located. The projection may be located through an inlet opening (not shown) formed in the first end plate 310. The outlet 170 may be a hole including a projection that protrudes in the opposite direction to the area where the module frame 140 is located. The projection may be located through an outlet opening (not shown) formed in the second end plate 320. However, such structures are merely examples of the inlets and outlets that may exist in the present invention, and there are no particular limitations on the form of the inlets and outlets as long as they can allow refrigerant to flow into the module frame 140 and discharge refrigerant from the module frame 140.

[0052] Referring again to Figures 4-8, 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 the first battery cell stack 120a and a second busbar frame assembly 190 provided on one side of the second battery cell stack 120b.

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

[0054] In this embodiment, the battery module 100 can be formed by electrically connecting a first battery cell stack 120a and a second battery cell stack 120b along the length direction (x-axis direction) of the battery cell 110. Therefore, busbar frame assemblies 180 and 190 can also be located 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 are electrically connected to form the battery module 100 according to this embodiment.

[0055] Busbar frame assemblies 180 and 190 may include electrically insulating material.

[0056] On the other hand, a flexible printed circuit board 330 can 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 mounted so as to extend in the longitudinal direction of the battery cell 110 and is configured to sense the battery cell 110. That is, as shown in Figure 5, the flexible printed circuit board 330 is located on the upper surface of the battery cell stack 120 and senses voltage data and thermal data of the battery cell 110. In particular, the flexible printed circuit board 330 can be electrically connected to the busbar frame assemblies 180 and 190 while bending at one end. This allows it to sense the voltage data of each battery cell 110 and transmit it to the outside.

[0057] Referring again to Figures 6 to 8 and Figure 10, the battery cell stack 120 includes a first battery cell stack 120a and a second battery cell stack 120b, which are arranged along the longitudinal direction in which the electrode leads 111 protrude from the battery cell 110.

[0058] Specifically, the battery module 100 of this embodiment can 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 this embodiment has an immersion cooling structure in which a refrigerant directly cools the battery cells 110 in order to improve cooling performance. However, in the case of an immersion cooling structure, an inlet 160 and an outlet 170 are required for each battery module 100, which is disadvantageous in terms of energy density. To compensate for the factors that reduce energy density due to such an immersion cooling structure, the battery module 100 according to this embodiment realizes a long module structure in which at least two battery cell stacks 120a and 120b are arranged in a single module frame 140.

[0059] Figure 12 is a perspective view of a fixed frame 130 according to one embodiment of the present invention. Figure 13 is a plan view of the fixed frame 130 of Figure 12.

[0060] Referring to Figures 6 to 8, 10, 12, and 13, the fixed frame 130 according to this embodiment includes side portions 131 that cover both sides 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 132 of the fixed frame 130 includes a bead surface 500, and adhesive members 210 are provided on the bead surface 500 that come into 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 members 210.

[0062] The bead surface 500 can be a region that protrudes in the direction in which the battery cell stack 120 is located, that is, upward, from the lower surface portion 132 of the fixed frame 130. The adhesive member 210 can be applied to this upwardly protruding bead surface 500.

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

[0064] In the case of an immersion cooling structure, an airtight structure is essential to seal the battery module 100 so that the refrigerant does not leak to the outside. Such an airtight structure is realized by housing the battery cells 110 in the internal space formed by the module frame 140 and the end plate 300. However, in this case, there is a problem that the battery cells 110 are not properly fixed inside the module frame 140. Therefore, in the battery module 100 of the immersion cooling structure, in order to fix the battery cells 110 and maintain a stable stacked structure of the battery cells 110, this embodiment realizes a fixing structure using a fixing frame 130. However, if an adhesive member is provided on the entire lower surface portion 132 of the fixing frame 130, the lower surface of the battery cell stack 120 may not be able to contact the refrigerant and the cooling performance may decrease. Therefore, in order to fix the battery cells 110 and at the same time secure a certain amount of cooling area on the lower surface of the battery cell stack 120, a bead surface 500 that protrudes upward is provided on a part of the lower surface portion 132 of the fixing frame 130. In other words, in areas where the bead surface 500 is not formed, the refrigerant can come into direct contact with the lower surface of the battery cell stack 120, thereby cooling the lower part of the battery cell 110.

[0065] The adhesive member 210 is a general term for a member that has adhesive properties for fixing the battery cells 110. For example, the adhesive member 210 can be an adhesive adhesive such as double-sided tape or a chemical adhesive that bonds through a chemical reaction during bonding to the bead surface 500 provided on the lower surface 132 of the fixing frame 130. The adhesive member 210 can maintain the laminated structure of the first battery cell laminate 120a and the second battery cell laminate 120b.

[0066] In another embodiment, the adhesive member 210 can be an insulating tape. In yet another embodiment, the adhesive member 210 can be formed from a resin. For example, the adhesive member 210 can be formed from resin or the like. When the adhesive member 210 comes into contact with other components, it hardens thereafter and bonds with the other components, fixing and supporting them.

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

[0068] An adhesive member 210 is applied to a portion or the entire area of ​​the bead surface 500, which is in contact with the lower end of the battery cell stack 120.

[0069] On the other hand, referring again to Figures 10 and 11, the first battery cell stack 120a and the second battery cell stack 120b can 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 can be positioned sequentially along a longitudinal direction that 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.

[0070] If the first battery cell stack 120a and the second battery cell stack 120b are positioned between the inlet 160 and the outlet 170, the refrigerant can maintain a unidirectional flow within the battery module 100. The refrigerant flowing 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 inside the module frame 140, allowing all the battery cells 110 to be cooled evenly.

[0071] The refrigerant can directly cool the battery cell stack 120 and other electrical components, as well as the busbar frame assemblies 180 and 190, which generate heat within the battery module 100, by directly contacting them and transferring heat. Therefore, compared to indirectly cooling the battery module 100 using a heat sink (Figures 2 and 6) as in the conventional method, the cooling efficiency can be improved, thereby extending the battery life. Referring again to Figures 12 and 13, the bead surface 500 is a region on the lower surface 132 of the fixed frame 130 that protrudes in the direction in which the battery cell stack 120 is located, and the region of the lower surface 132 of the fixed frame 130 other than the bead surface 500 can be a flow path for the refrigerant.

[0072] By allowing the refrigerant to flow through the area of ​​the lower surface 132 of the fixed frame 130 other than the bead surface 500, the refrigerant can directly contact the lower part of the battery cell stack 120 fixed to the fixed frame 130. This improves the cooling performance for the battery cells 110.

[0073] Using each battery cell 110 as a reference, the pattern of the bead surface 500 can be formed such that 20% to 40% of the area on the lower surface of each battery cell 110 is in contact with the adhesive member 210.

[0074] As described above, the area of ​​the lower surface portion 132 of the fixed frame 130 other than the bead surface 500 can be a flow path for the refrigerant. In this case, if 20% to 40% of the lower surface of the battery cell 110 is in contact with the adhesive member 210, then 60% to 80% of the lower surface of the battery cell 110 can be in direct contact with the refrigerant.

[0075] The ratio of the area of ​​the lower surface area of ​​the battery cell 110 that contacts the adhesive member 210 can be determined by the capacity of the battery cell 110, the size of the battery module 100, and other factors. By adjusting the ratio of the area of ​​the lower surface area of ​​the battery cell 110 that contacts the adhesive member 210, the cooling performance of the battery module 100 can be controlled and designed as intended.

[0076] Referring again to Figure 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 connected diagonally at an acute angle with respect to the length direction.

[0077] The shaded area DA serves to guide the flow of refrigerant from the inlet 160 to the outlet 170. Furthermore, by introducing the shaded area DA, it is possible to adjust the ratio of the area of ​​the lower surface area of ​​the battery cell 110 that is in contact with the adhesive member 210.

[0078] Although not shown in Figure 13, an adhesive member 210 is applied to a portion or the entire area of ​​the bead surface 500, which is in contact with the lower end of the battery cell stack 120.

[0079] While 20% to 40% of the lower surface area of ​​the battery cell 110 can come into contact with the bead surface 500, it is not limited to 20% to 40%.

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

[0081] As shown in Figure 14, when a straight line-shaped bead surface 500L is applied to the lower surface portion 132 of the fixed frame 130, the entire lower surface of the battery cell 110 that comes into contact with the adhesive member 210 on the line-shaped bead surface 500L is adhered to the adhesive member 210, rather than only 20% to 40% of the surface. In this case, the lower surface of the battery cell 110 does not come into contact with the coolant at all, resulting in a decrease in the cooling performance of the battery cell 110. Because the degree of cooling to the battery cells 110 differs, it leads to uneven cooling among the battery cells 110, which can lead to a decrease in the performance of the battery module.

[0082] On the other hand, in the embodiment shown in Figure 13, the line-shaped bead surface 500L has a shaded region DA, which allows each of the battery cells 110 to be in contact with the bead surface 500 in 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] On the other hand, the bead surface 500 may include block-type bead surfaces 500B in addition to line-type bead surfaces 500L. The block-type bead surfaces 500B can be located between line-type bead surfaces 500L.

[0084] The block-type bead surface 500B can consist of one or more. The line-type bead surface 500 can consist of one or more. The bead surface 500 can 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 each of the battery cells 110 so that only an area of ​​20% to 40% of it is in contact with the adhesive member 210. However, in other embodiments, the bead surface 500 can also 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-shaped bead surface 500B can be determined by 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 132 of the fixed frame 130 other than the block-shaped bead surface 500B may be a flow path for the refrigerant, so the position, size, and number of block-shaped bead surfaces 500B can be determined by the shape of the refrigerant flow path, etc.

[0086] More specifically, the bead surface 500 according to this embodiment may include a first bead 510 that extends in the longitudinal direction, a second bead 520 that extends 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 side surface 131 of the fixed frame 130 that is closer to the first bead 510 and the first bead 510, and a fifth bead 550 located between the side surface 131 of the fixed frame 130 that is closer to the second bead 520 and the second bead 520.

[0087] All embodiments of the linear bead surface 500L described herein are simply bead surfaces 500 that extend longitudinally from one end to the other of the fixed frame 130, as shown in Figure 13, and do not necessarily have to be in a straight line. In other words, the linear bead surface 500L may include the shaded area DA.

[0088] The third bead 530 can 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 can be symmetrical with respect to the third bead 530.

[0089] On the other hand, although not shown in Figure 13, an adhesive member 210 is applied to a part or the entire area of ​​the bead surface 500, which comes into contact with the lower end of the battery cell stack 120.

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

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

[0092] Although not shown in Figure 15, an adhesive member 210 that contacts the lower end of the battery cell stack 120 can be applied to a portion or the entire area of ​​the bead surface 500. While 20% to 40% of the lower surface of the battery cell 110 can contact the bead surface 500, this is not limited to 20% to 40%.

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

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

[0095] As shown in Figure 16, the line-shaped bead surface 500L can be divided into one or more branches. Although not shown in Figure 16, an adhesive member 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. An area of ​​20% to 40% of the lower surface of the battery cell 110 can contact the bead surface 500, but is not limited to 20% to 40%.

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

[0097] Referring to Figure 17, in this embodiment, the bead surface 500 is connected along the length direction, but the entire area of ​​the bead surface 500 can be the shaded section DA.

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

[0099] Referring to Figure 18, the bead surface 500 according to this embodiment may include a first bead 510 that extends in the longitudinal direction, a second bead 520 that extends 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 side surface 131 of the fixed frame 130 that is closer to the first bead 510 and the first bead 510, and a fifth bead 550 located between the side surface 131 of the fixed frame 130 that is closer to the second bead 520 and the second bead 520.

[0100] All embodiments of the linear bead surface 500L described herein are simply bead surfaces 500 that extend longitudinally from one end to the other of the fixed frame 130, as shown in Figure 18, and do not necessarily have to be in a straight line. In other words, the linear bead surface 500L may include the shaded area DA.

[0101] The third bead 530 can 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 can be symmetrical with respect to the third bead 530. Also, the fourth bead 540 and the fifth bead 550 can be symmetrical with respect to the third bead 530.

[0102] Although not shown in Figure 18, an adhesive member 210 is applied to a portion or the entire area of ​​the bead surface 500, which is in contact with the lower end of the battery cell stack 120.

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

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

[0105] 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 located above the battery modules 100, and at least one venting section 2000 provided on the side of the lower pack frame 1100. Here, the lower pack frame 1100 and the upper pack frame 1200 can be joined to each other by welding or other means to seal the inside 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 can be discharged to the outside through the venting section 2000.

[0106] 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.

[0107] The aforementioned battery module 100 and battery pack 1000 can be applied to a variety of devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but are not limited to these, and can be applied to a variety of devices that can use secondary batteries.

[0108] In this embodiment, terms indicating directions such as front, back, left, right, up, and down were used, but these terms are for explanatory convenience only and can change depending on the position of the object being examined, the observer's position, etc.

[0109] Although 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 by those skilled in the art that utilize the basic concepts of the present invention as 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 multiple battery cells including electrode leads are stacked, A fixed frame including both side portions and the bottom portion so as to cover both sides and the bottom of the aforementioned battery cell stack, The module frame in which the battery cell stack and the fixed frame are housed, The module frame has an inlet and an outlet for circulating the refrigerant, Includes, 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 surface of the fixed frame includes a bead surface, and adhesive members are provided on the bead surface that come into contact with 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 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. The battery module according to claim 1, wherein the inlet, the first battery cell stack, the second battery cell stack, and the outlet are sequentially positioned 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. The bead surface is a region that protrudes in the direction in which the battery cell stack is located on the lower surface. The battery module according to claim 1, wherein the area of ​​the lower surface of the fixed frame other than the bead surface is a flow path for the refrigerant.

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

6. The bead surface includes at least one line-shaped bead surface, The battery module according to claim 1, wherein the line-shaped bead surface has a diagonal region that connects at an acute angle with the longitudinal direction.

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

8. The aforementioned line-shaped bead surface is composed of multiple units. 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-type bead surface is located between the line-type bead surface and the side portion of the fixed frame.

10. The bead surface is A first bead is formed extending in the longitudinal direction, A second bead is formed extending in the longitudinal direction, A third bead is located between the first bead and the second bead, A fourth bead is located between the side of the fixed frame closest to the first bead and the first bead, The battery module according to claim 1, further comprising a fifth bead located between the side portion of the fixed frame closest to the second bead and the second bead.

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

12. The third bead is located in the center with respect to the two side portions of the fixed frame, The battery module according to 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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