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 are stacked; and at least one cooling member disposed on both sides of the battery cell stack or at least one between the plurality of battery cells. The cooling member includes a cooling channel which is a space through which a coolant flows inside the cooling member, and an air gap which is an empty space separated from the cooling channel.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2024 - 0020265 filed on February 13, 2024, and all the contents disclosed in the document of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the same.

Background Art

[0003] In modern society, as the use of portable devices such as mobile phones, notebook computers, video cameras, and digital cameras has become common, the development of technologies in the field related to such mobile devices has been active. In addition, rechargeable secondary batteries are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug - in hybrid electric vehicles (P - HEVs), etc. as a solution to problems such as air pollution caused by existing gasoline vehicles that use fossil fuels. Therefore, the need for the development of secondary batteries is increasing.

[0004] When the temperature of a secondary battery becomes higher than an appropriate temperature, the performance of the secondary battery may deteriorate, and in severe cases, there is also a risk of explosion or ignition. A battery module or a battery pack equipped with a large number of secondary batteries, that is, battery cells, may have heat generated from a large number of battery cells added together in a narrow space, causing the temperature to rise more rapidly and excessively. In the case of a battery module in which a large number of battery cells are stacked and a battery pack to which such a battery module is attached, a high output can be obtained, but it is not easy to remove the heat generated by the battery cells during charging and discharging. If the heat dissipation of the battery cells is not properly performed, the deterioration of the battery cells will accelerate, the lifespan will be shortened, and the possibility of explosion or ignition may increase.

[0005] As secondary batteries in the form of battery modules and battery packs, with numerous battery cells stacked on top of each other, began to be widely used, fire and explosion accidents occurred, making the safety of secondary batteries a more important issue. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] One embodiment of the present invention provides a battery module and a battery pack including the same, which have a structure that can control the expansion of battery cells and improve cooling performance. [Means for solving the problem]

[0007] A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked; and at least one cooling member disposed on both sides of the battery cell stack or at least one between the plurality of battery cells. The cooling member includes a cooling channel which is a space through which a coolant flows inside the cooling member, and an air gap which is an empty space separated from the cooling channel.

[0008] One surface of the cooling member may come into contact with one surface of at least one of the plurality of battery cells.

[0009] The cooling member is in the form of a plate and can provide surface cooling for at least one of the plurality of battery cells.

[0010] The air gap may include a first air gap and a second air gap, and the cooling channel may be located between the first air gap and the second air gap.

[0011] The first air gap, the cooling channel, and the second air gap may be located sequentially along the direction in which the plurality of battery cells are stacked.

[0012] The cooling channel may include a first cooling channel and a second cooling channel, and the air gap may be located between the first cooling channel and the second cooling channel.

[0013] The first cooling channel, the air gap, and the second cooling channel may be sequentially located along the direction in which the plurality of battery cells are stacked.

[0014] Each of the plurality of battery cells includes an electrode lead, and a busbar frame is positioned relative to the battery cell stack in a direction in which the electrode leads protrude from the plurality of battery cells, and busbars may be attached to the busbar frame.

[0015] The cooling member may include an inlet port for supplying the refrigerant to the cooling channel and an outlet port for discharging the refrigerant from the cooling channel. The inlet port and the outlet port may be connected to a pack refrigerant supply pipe and a pack refrigerant discharge pipe, respectively, passing through the busbar frame.

[0016] The inlet port and the outlet port may extend beyond the busbar frame with respect to the battery cell stack.

[0017] A battery pack according to one embodiment of the present invention includes a plurality of battery modules; a pack frame housing the plurality of battery modules; and a pack refrigerant supply pipe and a pack refrigerant discharge pipe connected to the cooling member and housed in the pack frame.

[0018] The cooling member may include an inlet port connected to the pack refrigerant supply pipe and an outlet port connected to the pack refrigerant discharge pipe. The inlet port and the outlet port may be connected to the pack refrigerant supply pipe and the pack refrigerant discharge pipe, respectively, by passing through a busbar frame located on one side of the battery cell stack.

[0019] The pack refrigerant supply pipe and the pack refrigerant discharge pipe can be arranged in a space between the plurality of battery modules and a side frame of the pack frame.

[0020] An automobile according to an embodiment of the present invention includes the battery pack.

Advantages of the Invention

[0021] According to an embodiment of the present invention, by arranging a cooling member having a cooling channel and an air gap adjacent to a battery cell, it is possible to control the expansion of the battery cell and further increase the cooling performance for the battery cell.

[0022] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned should be clearly understood by those skilled in the art from the description of the claims.

Brief Description of the Drawings

[0023] The following drawings attached to this specification illustrate embodiments of the present invention and serve to better understand the technical idea of the present invention together with the description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in those drawings. [Figure 1] FIG. 1 is a perspective view of a conventional battery module. [Figure 2] FIG. 2 is a cross-sectional view showing a cross-section cut along the cutting line A - A' of FIG. 1. [Figure 3] FIG. 3 is a perspective view showing a battery module according to an embodiment of the present invention. [Figure 4] FIG. 4 is an exploded perspective view of the battery module of FIG. 3. [Figure 5] FIG. 5 is an exploded perspective view showing a battery cell laminate, a first bus bar frame, and a second bus bar frame included in the battery module of FIG. 4. [Figure 6] FIG. 6 is a perspective view showing one of the battery cells included in the battery cell laminate of FIG. 5. [Figure 7] FIG. 7 is a perspective view showing a battery cell and a cooling member according to an embodiment of the present invention. [Figure 8] FIG. 8 is a perspective view showing a battery cell and a cooling member according to an embodiment of the present invention. [Figure 9] FIG. 9 is a perspective view showing a cooling member according to an embodiment of the present invention. [Figure 10] FIG. 10 is a partial perspective view showing the cooling member of FIG. 9 from another angle. [Figure 11] FIG. 11 is a cross-sectional view showing a cross-section cut along the cutting line B - B' of FIG. 9. [Figure 12] FIG. 12 is a cross-sectional view showing a cooling member according to another embodiment of the present invention. [Figure 13] FIG. 13 is a perspective view showing a battery cell laminate, a first bus bar frame, and a second bus bar frame according to an embodiment of the present invention. [Figure 14] FIG. 14 is a perspective view showing a first bus bar frame according to an embodiment of the present invention. [Figure 15] FIG. 15 is a front view showing a first bus bar frame according to an embodiment of the present invention. [Figure 16] FIG. 16 is a plan view showing a battery pack according to an embodiment of the present invention. [Figure 17] FIG. 17 is a perspective view illustrating an automobile including a battery pack according to an embodiment of the present invention.

[0024] In a part of the attached drawings, the corresponding components are assigned the same drawing numbers. Those skilled in the art should understand that the drawings clearly show the elements simply, and are not necessarily drawn to scale. For example, for the purpose of assisting the understanding of various embodiments, the sizes of some elements shown in the drawings may be exaggerated compared to other elements. Also, elements of known technology that are useful or essential in commercially feasible embodiments may sometimes not be depicted so as not to impede the gist of various embodiments of the present invention.

Embodiments for Carrying Out the Invention

[0025] 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.

[0026] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0027] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrarily shown for the sake of explanation and are not necessarily limited to those shown in the present invention. The thicknesses are shown enlarged in the drawings to clearly represent various layers and regions. In addition, the thicknesses of some layers and regions are exaggerated in the drawings for the sake of explanation.

[0028] 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.

[0029] Furthermore, when the specification as a whole states that a certain part "includes" a certain component, this means that, unless otherwise stated, other components are not excluded and other components may be included.

[0030] 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.

[0031] Currently, commercially available rechargeable batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium-ion batteries. Among these, lithium-ion batteries have the advantage of exhibiting almost no memory effect compared to nickel-based batteries, allowing for flexible charging and discharging, and boasting a very low self-discharge rate and high energy density.

[0032] Lithium secondary batteries can use lithium oxides and carbon materials as the positive electrode active material and negative electrode active material, respectively. A lithium secondary battery may include an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with the positive electrode active material and the negative electrode active material respectively, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0033] Lithium-ion secondary batteries can be classified into two types based on the shape of their casing: can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in an aluminum laminate sheet pouch.

[0034] In the case of secondary batteries used in small devices, two to three battery cells may be arranged, while in the case of secondary batteries used in medium to large devices such as automobiles, a battery module in which many battery cells are electrically connected may be used. Such a battery module can improve capacity and output by connecting many battery cells in series or parallel to each other to form a battery cell stack. One or more battery modules can be mounted together with various control and protection systems such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system to form a battery pack.

[0035] A battery pack includes battery modules as a sub-concept, and a battery module includes battery cells as a sub-concept. The number of battery cells in a battery module or the number of battery modules in a battery pack can be determined in various ways depending on the output and capacity of the battery pack required for the electric vehicle.

[0036] 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. Therefore, ensuring stable and effective cooling performance is extremely important when designing battery modules and battery packs. Cooling methods for battery modules and battery packs can be broadly classified into two categories: water cooling using refrigerants such as cooling water, and air cooling using cooling air. Of these, water cooling offers superior cooling performance and can effectively cool the high heat generated by large-capacity battery modules and battery packs.

[0037] Figure 1 is a perspective view of a conventional battery module, and Figure 2 is a cross-sectional view showing a cross-section cut along the cutting line A-A' in Figure 1. However, for convenience of explanation, Figure 2 also shows a heat sink 30 located beneath the battery module 10.

[0038] Referring to Figures 1 and 2, a conventional battery module 10 includes a battery cell stack 12 in which multiple battery cells 11 are stacked, and a module frame 20 that houses the battery cell stack 12. In this case, the battery cells 11 are pouch-type battery cells, and the pouch-type battery cells have a rectangular sheet structure.

[0039] Since a large number of battery cells 11 are stacked, the battery module 10 generates a large amount of heat during the charging and discharging process. Conventionally, a heat transfer path was created from the edge portion of the battery cell 11 to the heat sink 30 to cool the battery module 10.

[0040] The battery module 10 may include a thermal resin layer 40 located between the battery cell stack 12 and the bottom of the module frame 20. Furthermore, when the battery module 10 is attached to a pack frame to form a battery pack, a heat transfer member 50 and a heat sink 30 may be sequentially positioned beneath the battery module 10. The heat transfer member 50 may be a heat dissipation pad, and the heat sink 30 may include a cooling channel 31 through which a coolant such as cooling water flows. The edges of the battery cells 11, stacked in one direction, contact the thermal resin layer 40, and the heat generated from the battery cells 11 can be transferred to the outside of the battery module 10 sequentially through the thermal resin layer 40, the bottom of the module frame 20, the heat transfer member 50, and the heat sink 30. In other words, the conventional battery module 10 employs a water-cooled structure that dissipates heat through the edges of the battery cells 11.

[0041] While this water-cooling structure using the edge portion of the battery cell 11 has a relatively simple structure, its cooling performance is reduced, and there is a risk of cracks occurring in the pouch case of the battery cell 11 when the battery cell 11 undergoes significant expansion.

[0042] During repeated charging and discharging cycles or the initial charging process, the internal electrolyte of the battery cell 11 may decompose, generating gas and potentially causing the battery cell 11 to swell, a phenomenon known as swelling or breathing.

[0043] As the capacity of battery cells increases, the degree of expansion also increases significantly, and the number of battery cells applied to battery modules tends to increase gradually. Therefore, controlling the expansion of battery cells inside battery modules has become an important issue.

[0044] Referring again to Figure 2, the thermal resin layer 40 generally has adhesive properties and fixes the battery cell 11 in place. Therefore, when the battery cell 11 expands, high stress is generated at the edges of the battery cell 11, which can lead to cracks in the pouch case of the battery cell 11. The further out a battery cell 11 is located in the battery cell laminate 12, the greater the stress caused by expansion, and the greater the risk of cracking.

[0045] When applying a conventional water-cooling method using the edges to a battery module containing battery cells that expand in this way, there is a high risk of cracks occurring in the battery cells, and excessive stress may be applied, potentially compromising the structural safety of the battery module.

[0046] Therefore, there is a need for a battery module that has a novel cooling structure that can control the expansion of battery cells and improve cooling performance.

[0047] Figure 3 is a perspective view showing a battery module according to one embodiment of the present invention. Figure 4 is an exploded perspective view of the battery module of Figure 3. Figure 5 is an exploded perspective view showing the battery cell stack, first busbar frame, and second busbar frame included in the battery module of Figure 4. Figure 6 is a perspective view showing one of the battery cells included in the battery cell stack of Figure 5.

[0048] Referring to Figures 3 to 6, 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 are stacked; and at least one cooling member 600a disposed on both sides of the battery cell stack 120 or at least one between the battery cells 110. The cooling member 600a may include a cooling channel, which is a space through which a coolant flows, and an air gap, which is an empty space separated from the cooling channel. The form of the cooling member 600a will be described later.

[0049] The battery cell 110 in this embodiment may be of various forms, such as a pouch-type battery cell, a prismatic battery cell, or a cylindrical battery cell. As an example, as shown in Figures 4 to 6, the battery cell 110 in this embodiment may be a pouch-type battery cell. The following description will focus on pouch-type battery cells, but the battery cell 110 in this embodiment is not limited to this, and various types of battery cells can be applied.

[0050] The battery cell 110 according to this embodiment may be in a form in which an electrode assembly having electrode leads 111 protruding in one direction or both directions is housed in a pouch case 114. Such a battery cell 110 may be in the shape of a rectangular sheet. The battery cell 110 can be formed by housing the electrode assembly in a pouch case 114 made of a laminate sheet containing a resin layer and a metal layer, and then bonding the outer periphery of the pouch case 114. As an example, the battery cell 110 may have a structure in which two electrode leads 111 face each other and protrude from one end 114a and the other end 114b of the cell body 113, respectively. In another embodiment, the battery cell 110 may have a structure in which both electrode leads 111 protrude in one direction. One of the electrode leads 111 is a positive electrode lead and the other is a negative electrode lead.

[0051] The battery cell 110 may be manufactured by bonding both ends 114a, 114b of the pouch case 114 and one side portion 114c connecting them, with the electrode assembly (not shown) housed in the pouch case 114. In other words, the battery cell 110 according to one embodiment of the present invention has a total of three sealing portions 114s, the sealing portions 114s are sealed by methods such as fusion bonding, and the remaining other side portion may consist of a folding portion 115. That is, the battery cell 110 according to this embodiment may be a pouch-type secondary battery in which the electrode assembly is housed inside the pouch case 114, and the outer periphery of the pouch case 114 is sealed to form the sealing portions 114s. In Figure 6, only the pouch case 114 with sealing portions 114s formed on both ends 114a and 114b is shown, and the sealing portion on the side facing the folding portion 115 is not shown. However, the sealing portion on the side facing the folding portion 115 is folded to one side after sealing is completed for space utilization.

[0052] The laminated sheet pouch case 114 may include an inner resin layer for sealing, a metal layer to prevent penetration of materials, and an outermost outer resin layer. With respect to the electrode assembly inside the pouch case 114, the inner resin layer may be located on the innermost side, the outer resin layer on the outermost side, and the metal layer may be located between the inner and outer resin layers.

[0053] The outer resin layer may have excellent tensile strength and resistance to corrosion relative to its thickness to protect the electrode assembly from the outside, and may exhibit electrical insulation properties. Such an outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. A metal layer may prevent or suppress the inflow of air, moisture, etc., into the pouch-type secondary battery. Such a metal layer may include aluminum (Al). The inner resin layer may be heat-sealed by heat and / or pressure applied with the electrode assembly inside. Such an inner resin layer may include casted polypropylene (CPP) or polypropylene (PP).

[0054] The pouch case 114 may be divided into two parts, and a recessed housing portion may be formed in at least one of the two parts on which an electrode assembly can be placed. Along the outer circumference of such a housing portion, the inner resin layers of the two parts of the pouch case 114 may be joined together to form a sealing portion 114s. In this manner, the pouch case can be sealed and a battery cell 110, which is a pouch-type secondary battery, can be manufactured.

[0055] A battery module 100 can consist of multiple battery cells 110. For example, multiple battery cells 110 can be stacked along one direction so that they can be electrically connected to each other, forming a battery cell stack 120. For example, multiple battery cells 110 can be stacked upright along a direction parallel to the X-axis. With one side of the battery cell 110 parallel to the side portion 210b of the module frame 200 (described later), the battery cells 110 can be stacked from one side portion 210b to the other side portion 210b. As a result, the electrode leads 111 can protrude perpendicular to the direction in which the battery cells 110 are stacked. In a battery cell 110, one electrode lead 111 can protrude in the Y-axis direction, and the other electrode lead 111 can protrude in the -Y-axis direction. If the electrode leads 111 protrude in only one direction, the electrode leads 111 can protrude in either the Y-axis direction or the -Y-axis direction.

[0056] On the other hand, the battery module 100 according to this embodiment may include a module frame 200 that houses the battery cells 110. For example, the module frame 200 according to this embodiment may include a lower frame 210 on which the battery cells 110 are mounted and an upper cover 220 that covers the upper part of the battery cells 110.

[0057] The lower frame 210 and the upper cover 220 are joined together by welding or other methods at their corresponding corners, so that the module frame 200 can cover the upper, lower, and both sides of the battery cell stack 120. On the other hand, although not specifically shown, a module frame according to another embodiment of the present invention may be a monoframe in which the top, bottom, and both sides are integrated.

[0058] The lower frame 210 according to this embodiment may include a bottom portion 210a and two side portions 210b. The two side portions 210b may extend upward from opposing sides of the bottom portion 210a along a direction perpendicular to one surface of the bottom portion 210a. The bottom portion 210a and the two side portions 210b may cover the bottom surface and both sides of the battery cell stack 120. As described above, within the battery cell stack 120, one surface of the battery cell 110 is parallel to the side portion 210b of the lower frame 210, and the battery cells 110 may be stacked along a direction from one side portion 210b to the other side portion 210b.

[0059] On the other hand, in the battery module 100 according to this embodiment, a first end plate 310 and a second end plate 320 may be arranged on one side of the battery cell stack 120 in the direction in which the electrode leads 111 protrude, and on the opposite side, respectively. Such first end plates 310 and second end plates 320 can be joined to the module frame 200 by methods such as welding. The module frame 200, the first end plate 310, and the second end plate 320 may include metal materials to have a predetermined strength. The battery cell stack 120 can be covered by the module frame 200, the first end plate 310, and the second end plate 320, and protected from external shocks and vibrations.

[0060] On the other hand, the battery module 100 according to this embodiment may include a first busbar frame 410 and a second busbar frame 420 that cover one side of the battery cell stack 120 in the direction in which the electrode leads 111 protrude and the opposite side, respectively. The first busbar frame 410 may be located between the battery cell stack 120 and the first end plate 310, and the second busbar frame 420 may be located between the battery cell stack 120 and the second end plate 320. The first busbar frame 410 and the second busbar frame 420 may include an electrically insulating material, which can prevent or suppress short circuits caused by the busbars 510 and terminal busbars 520 (described later) coming into contact with other parts of the battery cell 110 other than the electrode leads 111.

[0061] Busbars 510, terminal busbars 520, and module connectors 530, etc., may be attached to the first busbar frame 410 and the second busbar frame 420, respectively. The busbars 510, terminal busbars 520, and module connectors 530, etc., can be attached to the opposite sides of the first and second busbar frames 410, 420 from the sides facing the battery cell stack 120. The busbars 510 can be electrically connected to the electrode leads 111 of the battery cells 110. For example, the busbars 510 and the electrode leads 111 may be joined by welding. Slits can be formed in the first and second busbar frames 410, 420, and the electrode leads 111 can pass through such slits to be connected to the busbars 510. The battery cells 110 can be electrically connected in series or parallel via such busbars 510.

[0062] The terminal busbar 520 is electrically connected to the electrode leads 111 and a portion of it may be exposed to the outside of the battery module 100. For example, a terminal busbar opening 321 may be formed in the second end plate 320. A portion of the terminal busbar 520 may be exposed to the outside of the battery module 100 through such a terminal busbar opening 321. The battery module 100 can form an HV (High Voltage) connection with other battery modules or electrical components through such a terminal busbar 520. Here, an HV connection is a power supply connection for supplying power that requires high voltage, and means a connection between battery cells or between battery modules.

[0063] The module connector 530 is a component for LV (Low Voltage) connection of the battery module 100. LV connection refers to an electrical connection that requires a relatively low voltage, such as battery electrical components. For example, a sensing component (not shown) can sense voltage data from the battery cell 110 and temperature data inside the battery module 100, and the module connector 530 connected to the sensing component can send the sensed voltage data and temperature data to a BMS (Battery Management System) located outside the battery module 100. Therefore, a part of the module connector 530 may also be exposed to the outside of the battery module 100. For example, a module connector opening 322 may be formed in the second end plate 320. The module connector 530 can be exposed to the outside of the battery module 100 through the module connector opening 322 and can be connected to an external BMS, etc.

[0064] The cooling member according to this embodiment will be described below.

[0065] Figures 7 and 8 are perspective views showing a battery cell and a cooling member according to one embodiment of the present invention. Figure 9 is a perspective view showing a cooling member according to one embodiment of the present invention. Figure 10 is a partial perspective view showing the cooling member of Figure 9 from a different angle. Figure 11 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of Figure 9.

[0066] Referring to Figures 4 through 11, the cooling member 600a according to this embodiment includes a cooling channel 600C, which is a space through which a refrigerant flows, and an air gap 600G, which is an empty space separated from the cooling channel 600C. One surface of such a cooling member 600a can be in contact with one surface of the battery cell 110. In other words, the cooling member 600a can surface-cool the battery cell 110 in a plate-like form. The refrigerant may be cooling water. The battery module 100 according to this embodiment can have a water-cooled cooling structure.

[0067] While the conventional battery module 10 shown in Figures 1 and 2 has an edge cooling structure in which heat is discharged through the edges of the battery cells 11, the battery module 100 according to this embodiment can have a surface cooling structure in which a cooling member 600a having a cooling channel 600C is in contact with one surface of the cell body 113 of the battery cell 110. Since one surface of the cell body 113 of the battery cell 110 can come into contact with the cooling member 600a, the cooling area is much larger, which has the advantage of superior cooling performance compared to the conventional battery module 10.

[0068] There are no special restrictions on the number or size of the cooling members 600a, as long as they can provide surface cooling for the battery cells 110 within the battery module 100. Multiple cooling members 600a are provided within the battery module 100, but some cooling members 600a may be placed between the battery cells 110, and others may be placed on both sides of the battery cell stack 120. As an example, Figures 7 and 8 show that three cooling members 600a are placed between the battery cells 110, and two cooling members 600a are each placed on both sides of the battery cell stack 120. In another embodiment, the cooling members 600a may be placed anywhere between the battery cells 110. The number of cooling members 600a may be appropriately changed considering the size, capacity, and heat generation of the battery module 100. Furthermore, there are no special restrictions on the size of the cooling members 600a, as long as they can cover 60% or more of the surface area of ​​one side of the battery cells 110.

[0069] As mentioned above, during repeated charging and discharging, the internal electrolyte of the battery cell 110 decomposes, generating gas and potentially causing the battery cell 110 to swell. In this swelling phenomenon, the battery cell 110 expands in the thickness direction. That is, the battery cell 110 can expand along the direction in which it is stacked (for example, the direction parallel to the X-axis in Figure 5). The cooling member 600a in this embodiment contains an air gap 600G inside, so the cooling member 600a can absorb this swelling of the battery cell 110. Conventionally, to absorb the swelling of the battery cell 110, a compression pad made of foam material was interposed between the battery cells 110. In this embodiment, the cooling member 600a located between the battery cells 110 can absorb the swelling of the battery cell 110 while replacing the function of the conventional compression pad. In other words, the cooling member 600a according to this embodiment can not only provide surface cooling for the battery cell 110, but also absorb the expansion of the battery cell 110. This prevents or suppresses the battery module 100 from deforming beyond its deformation limit due to the expansion of the battery cell 110.

[0070] On the other hand, in the case of a conventional battery module 10, the edges of the battery cells 11 are bonded and fixed to the thermal resin layer 40, so when expansion occurs, high stress is generated on the edges of the battery cells 11, which can lead to cracks in the battery cells 11. In the case of the battery module 100 according to this embodiment, the cooling member 600a is arranged between the battery cells 110, so the battery cells 110 are not bonded and fixed at specific points. Even if large expansion occurs in the battery cells 110, a certain degree of structural flexibility can be provided in the stacking direction of the battery cells 110, thus preventing or suppressing the occurrence of cracks in the battery cells 110.

[0071] On the other hand, as shown in Figures 8 and 11, the air gap 600G in this embodiment may include a first air gap 600G1 and a second air gap 600G2. The cooling channel 600C may be located between the first air gap 600G1 and the second air gap 600G2. The first air gap 600G1, the cooling channel 600C, and the second air gap 600G2 may be located sequentially along the direction in which the battery cells 110 are stacked (parallel to the X-axis, see Figure 8). In this embodiment, since the first air gap 600G1 and the second air gap 600G2 can be located adjacent to the battery cells 110, the expansion of the battery cells 110 can be absorbed more effectively.

[0072] Figure 12 is a cross-sectional view showing a cooling member according to another embodiment of the present invention.

[0073] Referring to Figure 12, a cooling member 600b according to another embodiment of the present invention includes a cooling channel 600C, which is a space through which a coolant flows, and an air gap 600G, which is an empty space separated from the cooling channel 600C. One surface of such a cooling member 600b can come into contact with one surface of the battery cell 110. In other words, the cooling member 600b can provide surface cooling to the battery cell 110 in a plate-like form. Similar to the cooling member 600a described above, the cooling member 600b according to this embodiment also includes a cooling channel 600C and an air gap 600G, and can therefore provide surface cooling to the battery cell 110 and absorb the expansion of the battery cell 110.

[0074] On the other hand, the cooling channel 600C of the cooling member 600b according to this embodiment may include a first cooling channel 600C1 and a second cooling channel 600C2. The air gap 600G may be located between the first cooling channel 600C1 and the second cooling channel 600C2. The first cooling channel 600C1, the air gap 600G, and the second cooling channel 600C2 can be sequentially located along the direction in which the battery cells 110 are stacked (parallel to the X-axis, see Figure 8). In this embodiment, since the first cooling channel 600C1 and the second cooling channel 600C2 can be located adjacent to the battery cells 110, the cooling performance for the battery cells 110 can be further increased.

[0075] Figure 13 is a perspective view showing a battery cell stack, a first busbar frame, and a second busbar frame according to one embodiment of the present invention. Figures 14 and 15 are a perspective view and a front view, respectively, of the first busbar frame according to one embodiment of the present invention.

[0076] Referring to Figures 5, 8 to 11, and 13 to 15, as described above, the battery cell 110 according to this embodiment may include electrode leads 111, and busbar frames 410 and 420 may be arranged in a direction in which the electrode leads 111 protrude from the battery cell 110 relative to the battery cell stack 120, and busbars 510 may be attached to such busbar frames 410 and 420. As an example, a first busbar frame 410 and a second busbar frame 420 may be arranged on each side of the battery cell stack 120.

[0077] The cooling member 600a according to this embodiment may include an inlet port 610 for supplying refrigerant to the cooling channel 600C and an outlet port 620 for discharging refrigerant from the cooling channel 600C. The inlet port 610 and the outlet port 620 may pass through the first busbar frame 410 and be connected to a pack refrigerant supply pipe and a pack refrigerant discharge pipe, respectively. The pack refrigerant supply pipe and the pack refrigerant discharge pipe will be described later with reference to Figure 16.

[0078] The inlet port 610 and outlet port 620 can be tubular members extending from one side of the cooling member 600a, and the refrigerant can flow into the cooling channel 600C through the inlet port 610 and then be discharged from the cooling channel 600C through the outlet port 620. In other words, the cooling member 600a can have a refrigerant circulation structure through the inlet port 610 and outlet port 620.

[0079] The first busbar frame 410 may be provided with an inlet hole 410H1 and an outlet hole 410H2, respectively. The inlet port 610 of the cooling member 600a can pass through the inlet hole 410H1 of the first busbar frame 410, and the outlet port 620 of the cooling member 600a can pass through the outlet hole 410H2 of the first busbar frame 410. The inlet port 610 and the outlet port 620 extend further than the first busbar frame 410 with respect to the battery cell stack 120, and can pass through the inlet hole 410H1 and the outlet hole 410H2, respectively. The inlet port 610 and the outlet port 620, having passed through the inlet hole 410H1 and the outlet hole 410H2, respectively, can be connected to a pack refrigerant supply pipe and a pack refrigerant discharge pipe, which will be described later. Each of the inlet holes 410H1 and outlet holes 410H2 can be formed in the first busbar frame 410 in a number equal to the number of cooling members 600a.

[0080] As in this embodiment, the inlet port 610 and the outlet port 620 pass through the first busbar frame 410 and extend beyond the location of the first busbar frame 410. Therefore, the portion of the inlet port 610 connected to the pack refrigerant supply pipe and the portion of the outlet port 620 connected to the pack refrigerant discharge pipe can be located a certain distance from electrical connecting components such as electrode leads and busbars. In other words, by separating the cooling connecting components to a certain extent from the electrical connecting components, the insulation of the cooling member 600a can be ensured.

[0081] Furthermore, since the inlet port 610 and outlet port 620 are fitted into the inlet hole 410H1 and outlet hole 410H2 and pass through the inlet hole 410H1 and outlet hole 410H2, the inlet port 610 and outlet port 620 can be fixed in place by the inlet hole 410H1 and outlet hole 410H2. As a result, the inlet port 610 and outlet port 620 can be made safe against external vibrations and shocks, and refrigerant leakage from the inlet port 610 and outlet port 620 can be prevented or suppressed.

[0082] On the other hand, referring to Figures 4, 5 and 13 to 15 together, as described above, the battery module 100 may include a first end plate 310, and the first busbar frame 410 may be located between the first end plate 310 and the battery cell stack 120. Such a first end plate 310 may have an external inlet hole 310H1 and an external outlet hole 310H2 formed therein. The external inlet hole 310H1 and the external outlet hole 310H2 may be located to correspond to the inlet hole 410H1 and outlet hole 410H2 of the first busbar frame 410, respectively.

[0083] The inlet port 610, which passes through the inlet hole 410H1 of the first busbar frame 410, passes through the external inlet hole 310H1 of the first end plate 310 and is exposed to the outside of the battery module 100, and can be connected to the pack refrigerant supply pipe described later. The outlet port 620, which passes through the outlet hole 410H2 of the first busbar frame 410, passes through the external outlet hole 310H2 of the first end plate 310 and is exposed to the outside of the battery module 100, and can be connected to the pack refrigerant discharge pipe described later.

[0084] The following describes a battery pack according to one embodiment of the present invention.

[0085] Figure 16 is a plan view showing a battery pack according to one embodiment of the present invention.

[0086] Referring to Figures 4, 5, and 16, a battery pack 1000 according to one embodiment of the present invention includes a battery module 100; a pack frame 1100 housing the battery module 100; and a pack refrigerant supply pipe 1200 and a pack refrigerant discharge pipe 1300 connected to a cooling member 600a and housed in the pack frame.

[0087] As described above, the cooling member 600a may include an inlet port 610 connected to the pack refrigerant supply pipe 1200 and an outlet port 620 connected to the pack refrigerant discharge pipe 1300, and the inlet port 610 and the outlet port 620 can pass through the first busbar frame 410 and be connected to the pack refrigerant supply pipe 1200 and the pack refrigerant discharge pipe 1300, respectively. For example, the inlet port 610, which passes through the inlet hole 410H1 of the first busbar frame 410 and the external inlet hole 310H1 of the first end plate 310, can be connected to the pack refrigerant supply pipe 1200. Also, the outlet port 620, which passes through the outlet hole 410H2 of the first busbar frame 410 and the external outlet hole 310H2 of the first end plate 310, can be connected to the pack refrigerant discharge pipe 1300. The refrigerant supply pipe 1200 and the refrigerant discharge pipe 1300 can be connected to a refrigerant circulation system (not shown) located inside or outside the battery pack 1000. In other words, refrigerant moving from the refrigerant circulation system along the refrigerant supply pipe 1200 flows into the cooling channel 600C via the inlet port 610, and the refrigerant subsequently discharged from the cooling channel 600C via the outlet port 620 can be recovered back into the refrigerant circulation system along the refrigerant discharge pipe 1300. Through this process, a refrigerant circulation structure can be realized within the battery pack 1000.

[0088] The pack frame 1100 according to this embodiment may include a bottom frame 1110 on which the battery module 100 is mounted, and a side frame 1120 connected to the periphery of the bottom frame 1110. Such a side frame 1120 may extend in a direction perpendicular to one surface of the bottom frame 1110. The bottom frame 1110 and the side frame 1120 provide an internal space with an open top, in which the battery module 100 can be housed. On the other hand, a pack cover (not shown) may cover the open top of the pack frame 1100.

[0089] In this embodiment, the pack refrigerant supply pipe 1200 and the pack refrigerant discharge pipe 1300 can be arranged in the space between the battery module 100 and the side frame 1120 of the pack frame 1100. Furthermore, a portion of the battery module 100 can be arranged to face the second end plate 320. As described above, a terminal busbar opening 321 can be formed in the second end plate 320, and the terminal busbar 520 can be exposed through the terminal busbar opening 321. The space between the battery module 100 facing the second end plate 320 can be used as the space for HV (High voltage) connection by the terminal busbar 520. In other words, the HV line connected to the terminal busbar 520 can be arranged in the space between the battery module 100.

[0090] The pack refrigerant supply pipe 1200 and the pack refrigerant discharge pipe 1300 can be positioned in the space between the battery module 100 and the side frame 1120 of the pack frame 1100 so as to be connected to the inlet port 610 and the outlet port 620, which pass through the external inlet hole 310H1 and the external outlet hole 310H2 of the first end plate 310, respectively.

[0091] Therefore, from the perspective of any one battery module 100, the pack refrigerant supply pipe 1200 and the pack refrigerant discharge pipe 1300 can be located on opposite sides of the HV line. In other words, the pack refrigerant supply pipe 1200 and the pack refrigerant discharge pipe 1300 can be located outside the first end plate 310, and the HV line connected to the terminal bus bar 520 can be located outside the second end plate 320.

[0092] By positioning the refrigerant supply pipe 1200 and the refrigerant discharge pipe 1300 far away from the HV line, problems such as short circuits caused by refrigerant leaking from the refrigerant supply pipe 1200 and the refrigerant discharge pipe 1300 coming into contact with the HV line can be prevented or suppressed. In other words, in the battery pack 1000 according to this embodiment, by spatially separating the refrigerant supply pipe 1200 and the refrigerant discharge pipe 1300, through which the refrigerant flows, from the HV line, insulation performance and safety against refrigerant leakage can be ensured.

[0093] In this embodiment, terms indicating direction such as front, back, left, right, and up and down were used, but such terms are merely for explanatory convenience and can change depending on the position of the object in question, the observer's position, etc.

[0094] 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.

[0095] The aforementioned battery modules and battery packs can be applied to a variety of devices. For example, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, as well as to ESS (Energy Storage Systems), but are not limited to these, and can be applied to a variety of devices that can use secondary batteries.

[0096] Figure 17 illustrates an automobile 2000 that includes a battery pack according to one embodiment of the present invention. As shown in Figure 17, the battery pack 1000 according to the present invention may be provided in the automobile 2000. Alternatively, the battery module 100 according to the present invention may be provided in the automobile 2000. In addition to such battery pack 1000 and battery module 100, the automobile 2000 according to the present invention may further include a variety of other components included in the automobile 2000. For example, the automobile 2000 according to the present invention may further include a vehicle body, a motor, an ECU (electronic control unit) or other control devices, etc.

[0097] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, utilizing the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. Therefore, the technical scope of the diverse embodiments of the present invention is not limited by the contents described in the detailed description of the specification, but must be determined by the claims.

Claims

1. A battery cell stack in which multiple battery cells are stacked; and The cooling member comprises at least one cooling member positioned on at least one of the two sides of the battery cell stack or between the plurality of battery cells, wherein each of the two sides extends along a direction perpendicular to the stacking direction of the plurality of battery cells; The cooling element includes a cooling channel, which is a space through which a liquid coolant flows, and an air gap, which is an empty space separated from the cooling channel, in a battery module.

2. The battery module according to claim 1, wherein one surface of the cooling member is in contact with one surface of at least one of the plurality of battery cells.

3. The battery module according to claim 1, wherein the cooling member is in the form of a plate and provides surface cooling to at least one of the plurality of battery cells.

4. The air gap includes a first air gap and a second air gap, The battery module according to claim 1, wherein the cooling channel is located between the first air gap and the second air gap.

5. The battery module according to claim 4, wherein the first air gap, the cooling channel, and the second air gap are sequentially located along the direction in which the plurality of battery cells are stacked.

6. The aforementioned cooling channel includes a first cooling channel and a second cooling channel. The battery module according to claim 1, wherein the air gap is located between the first cooling channel and the second cooling channel.

7. The battery module according to claim 6, wherein the first cooling channel, the air gap, and the second cooling channel are sequentially located along the direction in which the plurality of battery cells are stacked.

8. Each of the aforementioned plurality of battery cells includes an electrode lead, With respect to the aforementioned battery cell stack, the busbar frame is arranged in a direction in which the electrode leads protrude from the plurality of battery cells. The battery module according to claim 1, wherein a busbar is attached to the busbar frame.

9. The cooling member includes an inlet port for supplying the refrigerant to the cooling channel and an outlet port for discharging the refrigerant from the cooling channel. The battery module according to claim 8, wherein the inlet port and the outlet port are connected to a pack refrigerant supply pipe and a pack refrigerant discharge pipe, respectively, passing through the busbar frame.

10. The battery module according to claim 9, wherein the inlet port and the outlet port extend further than the busbar frame with respect to the battery cell stack.

11. A plurality of battery modules according to claim 1; A pack frame housing the plurality of battery modules; and A battery pack including a pack refrigerant supply pipe and a pack refrigerant discharge pipe, which are connected to the cooling member and housed in the pack frame.

12. The cooling member includes an inlet port connected to the pack refrigerant supply pipe and an outlet port connected to the pack refrigerant discharge pipe. The battery pack according to claim 11, wherein the inlet port and the outlet port are connected to the pack refrigerant supply pipe and the pack refrigerant discharge pipe, respectively, by passing through a busbar frame located on one side of the battery cell stack.

13. The battery pack according to claim 12, wherein the pack refrigerant supply pipe and the pack refrigerant discharge pipe are arranged in the space between the plurality of battery modules and the side frame of the pack frame.

14. An automobile comprising the battery pack described in any one of claims 11 to 13.

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