Battery pack and device including the battery pack

Abstract

A battery pack according to an embodiment of the present disclosure includes: a plurality of battery modules, the plurality of battery modules including: a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a radiator located below the bottom of the module frame; a battery pack frame for accommodating the plurality of battery modules; and a refrigerant transfer bolt for fastening the bottom of the module frame, the radiator, and the battery pack frame, wherein the battery pack frame includes a battery pack refrigerant pipe for supplying and discharging refrigerant, wherein a connection pipe is formed on the refrigerant transfer bolt for connecting the battery pack refrigerant pipe and the radiator, and wherein the refrigerant transfer bolt includes an opening / closing member that opens or blocks the connection pipe in response to the temperature of the refrigerant.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of Korean Patent Application No. 10 - 2020 - 0106097, filed with the Korean Intellectual Property Office on Aug. 24, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0003] The present disclosure relates to a battery pack and a device including the battery pack, and more particularly, to a battery pack having improved cooling performance and safety and a device including the battery pack. Background Art

[0004] In modern society, as portable devices such as mobile phones, laptop computers, portable cameras, and digital cameras have been in daily use, the development of technologies in the fields related to the above - mentioned mobile devices has become active. In addition, in an attempt to solve problems such as air pollution caused by existing gasoline vehicles using fossil fuels, rechargeable / dischargeable secondary batteries are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug - in hybrid electric vehicles (P - HEVs), etc. Therefore, the development of secondary batteries is increasingly required.

[0005] Currently commercialized secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries have received attention because they have advantages over nickel - type secondary batteries, for example, they hardly exhibit a memory effect and thus can be freely charged and discharged, and have a very low self - discharge rate and high energy density.

[0006] Such lithium secondary batteries mainly use lithium - based oxides and carbonaceous materials as the positive electrode active material and the negative electrode active material, respectively. The lithium secondary battery includes: an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with a positive electrode active material and a negative electrode active material, are placed with a separator interposed therebetween; and a battery case that seals and houses the electrode assembly together with an electrolyte solution.

[0007] Generally, based on the shape of the external material, lithium secondary batteries can be classified into can - type secondary batteries in which the electrode assembly is installed in a metal can and pouch - type secondary batteries in which the electrode assembly is installed in a pouch made of an aluminum laminate.

[0008] In the case of a secondary battery for a small device, two to three battery cells are placed, but in the case of a secondary battery for a medium or large device (such as an automobile), a battery module in which a large number of battery cells are electrically connected is used. In such a battery module, a large number of battery cells are connected to each other in series or in parallel to form a cell stack, thereby increasing the capacity and output. In addition, one or more battery modules may be installed together with various control and protection systems (such as a BMS (Battery Management System) and a cooling system) to form a battery pack.

[0009] When the temperature of a secondary battery rises above an appropriate temperature, the performance of the secondary battery may deteriorate, and in the worst case, there is also a risk of explosion or fire. In particular, a large number of secondary batteries (i.e., a battery module or a battery pack having battery cells) may accumulate heat generated from a large number of battery cells in a narrow space, such that the temperature may rise more rapidly and excessively. In other words, a battery module in which a large number of battery cells are stacked and a battery pack equipped with such a battery module can obtain a high output, but it is not easy to dissipate the heat generated from the battery cells during charging and discharging. When the heat dissipation of the battery cells is not properly performed, the deterioration of the battery cells is accelerated, the lifespan is shortened, and the possibility of explosion or fire increases.

[0010] Moreover, in the case of a medium or large battery module included in a vehicle battery pack, the battery module is frequently exposed to direct sunlight and may be subjected to high temperature conditions, such as in summer or in a desert area.

[0011] Therefore, when constructing a battery module or a battery pack, it may be very important to stably and effectively ensure the cooling performance.

[0012] Figure 1 is a partial perspective view of a conventional battery pack, and Figure 2 is a partial perspective view showing a method of mounting Figure 1 the battery modules included in the battery pack.

[0013] Referring to Figure 1 and Figure 2 , a conventional battery pack may include a plurality of battery modules 10 and a battery pack frame 11 that houses the plurality of battery modules. For convenience of explanation, only one battery module is shown in Figure 1 .

[0014] The conventional battery pack is provided with a refrigerant pipe for cooling the battery module 10, and refrigerant is supplied via a refrigerant pipe connector 13 connected to the refrigerant pipe. This refrigerant is usually cooling water, and a fluid indirect cooling structure is applied, in which such cooling water flows inside the battery pack to lower the temperature.

[0015] Meanwhile, when the battery module 10 is received in the battery pack frame 11, mounting holes are provided at four corners, and mounting bolts 12 can pass through the mounting holes and be fastened to the battery pack frame 11. Such mounting connections can be formed for each battery module 10.

[0016] At this time, a cooling structure (such as a refrigerant pipe connector 13 for cooling the battery module 10) and a mounting structure (such as a mounting bolt 12 for mounting the battery module 10) are separate structures, and there are problems that each structure has many parts and is complex.

[0017] Due to assembly defects or accidents during operation, the following may occur: Refrigerant leaks from the refrigerant pipes, refrigerant pipe connectors 13, etc., and the leaked refrigerant may penetrate into the interior of the battery pack and cause a fire or explosion.

[0018] Therefore, there is a need to develop a battery pack that can minimize damage caused by refrigerant leakage while improving cooling performance. Summary of the Invention

[0019] Technical Problem

[0020] An object of the present disclosure is to provide a battery pack capable of preventing damage caused by refrigerant leakage while improving cooling performance, and an apparatus including the battery pack.

[0021] However, the problems to be solved by the embodiments of the present disclosure are not limited to the above problems, and various extensions can be made within the scope of the technical idea included in the present disclosure.

[0022] Technical Solution

[0023] According to an embodiment of the present disclosure, there is provided a battery pack including: a plurality of battery modules including: a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a radiator located below the bottom of the module frame; a battery pack frame for accommodating the plurality of battery modules; and a refrigerant transfer bolt for fastening the bottom of the module frame, the radiator, and the battery pack frame, wherein the battery pack frame includes a battery pack refrigerant pipe for supplying and discharging refrigerant, wherein a connection pipe is formed on the refrigerant transfer bolt for connecting the battery pack refrigerant pipe and the radiator, and wherein the refrigerant transfer bolt includes an open / close member that opens or blocks the connection pipe in response to the temperature of the refrigerant.

[0024] The open / close member may include a shape memory alloy and respond to the temperature of the refrigerant.

[0025] The refrigerant transfer bolt may include a first opening and a second opening, the first opening and the second opening being connected to a connection pipe. The first opening may be placed inside the refrigerant pipe of the battery pack, and the second opening may be placed between the bottom of the module frame and the radiator. The opening / closing member may adjust the opening / closing of the second opening in response to the temperature of the refrigerant.

[0026] The opening / closing member may include: a blocking portion for opening or closing the connection pipe; and a spring portion connected to the blocking portion and including a shape memory alloy.

[0027] The spring portion may deform in shape in response to the temperature of the refrigerant, and the blocking portion may move up and down according to the shape deformation of the spring portion to open or block the connection pipe.

[0028] The spring portion may be a coil spring or a plate spring.

[0029] The refrigerant opening may be formed in the battery pack frame, and the refrigerant opening may include a stepped portion for supporting one end of the spring portion.

[0030] The module frame may include a module frame extension formed by extending a part of the bottom of the module frame. The radiator may include a radiator extension extending from one side of the radiator to the portion where the module frame extension is located, and the refrigerant transfer bolt may fasten the module frame extension, the radiator extension, and the battery pack frame.

[0031] The refrigerant opening may be formed in the battery pack frame, a first mounting hole may be formed in the module frame extension, and a second mounting hole may be formed in the radiator extension. The refrigerant transfer bolt may pass through the first mounting hole, the second mounting hole, and the refrigerant opening.

[0032] The refrigerant transfer bolt may include a first opening and a second opening, the first opening and the second opening being connected to a connection pipe. The first opening may be placed inside the refrigerant pipe of the battery pack, and the second opening may be placed between the bottom of the module frame and the radiator. The opening direction of the first opening may be parallel to the penetration direction of the connection pipe, and the opening direction of the second opening may be perpendicular to the penetration direction of the connection pipe.

[0033] The refrigerant transfer bolt may include: a body portion in which the connection pipe is formed; and a head located at the upper end of the body portion.

[0034] The battery pack may further include a gasket that surrounds the body portion, and the gasket may be located in at least one of the following positions: between the head and a module frame extension formed by extending a part of the bottom of the module frame; and between the radiator and the battery pack frame.

[0035] Protrusions may be respectively formed on the front and rear surfaces of the battery module, and the battery pack may further include fixing brackets that are respectively located on the front and rear surfaces of the battery module and are coupled to the battery pack frame while wrapping the protrusions.

[0036] The battery pack frame may include: a support frame for supporting the battery module; and a lower frame located below the support frame, and the battery pack refrigerant pipe may be located between the support frame and the lower frame.

[0037] Advantageous Effects

[0038] According to an embodiment of the present disclosure, it is possible to simultaneously perform installation fixation and pressure sealing through a refrigerant transfer bolt having a refrigerant flow path, thereby reducing the number of parts and simplifying the structure.

[0039] In addition, it is possible to minimize the influence on the alignment between through holes required for supplying refrigerant, thereby reducing the possibility of refrigerant leakage.

[0040] In addition, an opening / closing member is disposed such that it is possible to actively adjust the opening / closing of a connection pipe formed in the refrigerant transfer bolt according to the temperature of the refrigerant.

[0041] Furthermore, through an improved fixing bracket structure, the battery module can be firmly fixed and at the same time damage caused by refrigerant leakage can be effectively prevented.

[0042] The effects of the present disclosure are not limited to the above effects, and according to the description of the appended claims, those skilled in the art will clearly understand additional other effects not described above. Description of the Drawings

[0043] Figure 1 is a partial perspective view of a conventional battery pack;

[0044] Figure 2 is a partial perspective view showing a method of installing Figure 1 the battery module included in the battery pack;

[0045] Figure 3 is a perspective view showing the battery module and the battery pack frame included in the battery pack according to an embodiment of the present disclosure;

[0046] Figure 4is an exploded perspective view of a fixing bracket for fixing a battery module of Figure 3 to a battery pack frame;

[0047] Figure 5 is Figure 3 an exploded perspective view of the battery module of

[0048] Figure 6 is a partial perspective view showing section “A” of Figure 3 in an enlarged manner;

[0049] Figure 7 is a partial cross-sectional view of a cross-section taken along cutting line B-B' of Figure 6 ;

[0050] Figure 8 and Figure 9 are partial perspective views showing section “E” of Figure 7 in an enlarged manner;

[0051] Figure 10 a to Figure 10 c are views of a refrigerant transfer bolt according to an embodiment of the present disclosure when observed from various angles;

[0052] Figure 11 a and Figure 11 b are views of a refrigerant transfer bolt and an opening / closing member according to an embodiment of the present disclosure when observed from various angles;

[0053] Figure 12 a and Figure 12 b are views of a refrigerant transfer bolt and an opening / closing member according to a modified embodiment of the present disclosure when observed from various angles;

[0054] Figure 13 is a partial cross-sectional view taken along cutting line C-C' of Figure 6 ; and

[0055] Figure 14 is a partial cross-sectional view of a cross-section taken along cutting line D-D' of Figure 6 ; DETAILED DESCRIPTION

[0056] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0057] For clarity, descriptions of parts irrelevant to the specification will be omitted herein, and throughout the specification, like reference numerals denote like elements.

[0058] In addition, in the drawings, for convenience of description, the dimensions and thicknesses of each element are arbitrarily shown, and the present disclosure is not necessarily limited to those shown in the drawings. In the drawings, for clarity, the thicknesses of layers, regions, etc. are exaggerated. In the drawings, for convenience of description, the thicknesses of some layers and regions are exaggerated.

[0059] In addition, it will be understood that when an element (such as a layer, film, region, or plate) is referred to as being "on" or "above" another element, the element can be directly on the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly" "on" another element, this means that no other intervening elements are present. Further, the terms "on" or "above" mean being placed on or under the reference part, and do not necessarily mean being placed on the upper end of the reference part in the opposite direction of gravity.

[0060] In addition, throughout the specification, when a part is referred to as "including" a specific component, this means that the part can further include other components without excluding other components, unless otherwise stated.

[0061] In addition, throughout the specification, when referred to as "planar", this means observing the target part from the upper side, and when referred to as "section", this means observing the target part from the side of a vertically cut section.

[0062] Figure 3 is a perspective view showing a battery module and a battery pack frame included in a battery pack according to an embodiment of the present disclosure. Figure 4 is a perspective view showing a fixing bracket for fixing the Figure 3 battery module to the battery pack frame. Figure 5 is Figure 3 an exploded perspective view of the battery module.

[0063] Refer to Figures 3 to 5 , a battery pack according to an embodiment of the present disclosure includes: a plurality of battery modules 100; a battery pack frame 1100 for accommodating the plurality of battery modules 100; and a refrigerant transfer bolt. The battery module 100 includes: a battery cell stack 120 in which a plurality of battery cells 110 are stacked; a module frame 200 for accommodating the battery cell stack 120; and a radiator 300 located below the bottom 210a of the module frame 200. The refrigerant transfer bolt will be described later.

[0064] The battery cell 110 can be a pouch-type battery cell. The pouch-type battery cell can be formed by accommodating an electrode assembly in a pouch casing of a laminated sheet including a resin layer and a metal layer, and then heat-sealing the outer peripheral portion of the pouch casing. At this time, the battery cell 110 can be formed into a rectangular sheet-like structure.

[0065] Such battery cells 110 can be constructed of a plurality of battery cells, and the plurality of battery cells 110 are stacked to be electrically connected to each other, thereby forming a battery cell stack 120. In particular, as shown in Figure 5 the plurality of battery cells 110 can be stacked in a direction parallel to the x-axis.

[0066] The battery cell stack 120 according to the present embodiment can be a large-area module in which the number of battery cells 110 is increased compared to the conventional case. Specifically, each battery module 100 can include 32 to 48 battery cells 110. In the case of such a large-area module, the horizontal length of the battery module becomes longer. Here, the horizontal length can mean the length in the direction of stacking the battery cells 110, that is, the direction parallel to the x-axis.

[0067] The module frame 200 for accommodating the battery cell stack 120 can include an upper cover 220 and a U-shaped frame 210.

[0068] The U-shaped frame 210 can include a bottom 210a and two side surface portions 210b extending upward from both ends of the bottom 210a. The bottom 210a can cover the lower surface (-z-axis direction) of the battery cell stack 120, and the side surface portions 210b can cover the two side surfaces (x-axis direction and -x-axis direction) of the battery cell stack 120.

[0069] The upper cover 220 can be formed into a single-plate structure that wraps the remaining upper surface (z-axis direction) except for the lower surface and the two side surfaces wrapped by the U-shaped frame 210. The upper cover 220 and the U-shaped frame 210 can be joined to each other in a state where they are in contact with each other at the corresponding corners by welding or the like, thereby forming a structure that vertically and horizontally covers the battery cell stack 120. The battery cell stack 120 can be physically protected by the upper cover 220 and the U-shaped frame 210. For this purpose, the upper cover 220 and the U-shaped frame 210 can include a metal material having a predetermined strength.

[0070] Meanwhile, although not specifically shown in the drawings, the module frame 200 according to a modified embodiment can be a single frame in the form of a metal plate, in which the upper surface, the lower surface, and the two side surfaces are integrated. That is, this is not a structure in which the U-shaped frame 210 and the upper cover 220 are joined to each other, but a structure in which the upper surface, the lower surface, and the two side surfaces are integrated by being manufactured by extrusion molding.

[0071] The end plate 400 can be located on the front and rear surfaces (in the y-axis and -y-axis directions) of the battery cell stack 120 such that the end plate 400 can be formed to cover the battery cell stack 120. The end plate 400 can physically protect the battery cell stack 120 and other electronic devices against external impacts.

[0072] Meanwhile, although not specifically shown in the figures, a bus bar frame on which a bus bar is mounted, an insulating cover for electrical insulation, etc. can be located between the battery cell stack 120 and the end plate 400.

[0073] Meanwhile, the battery module 100 according to the present embodiment includes a radiator 300 that is located below the bottom 210a of the module frame 200. The bottom 210a of the module frame 200 can constitute the upper plate of the radiator 300, and the recessed portion 340 of the radiator 300 and the bottom 210a of the module frame 200 can form a flow channel for the refrigerant.

[0074] Specifically, the radiator 300 can include: a lower plate 310 that forms the skeleton of the radiator 300 and is directly coupled to the bottom 210a of the module frame 200 by welding or the like; and a recessed portion 340 that is a path through which the refrigerant flows.

[0075] The recessed portion 340 of the radiator 300 is formed corresponding to the lower plate 310 as a portion recessed on the lower side. The recessed portion 340 can be a U-shaped pipe having a U-shaped cross-section cut in a direction perpendicular to the extending direction of the refrigerant flow channel in the xz plane, and the bottom 210a can be located on the open upper side of the U-shaped pipe. When the radiator 300 comes into contact with the bottom 210a, a region through which the refrigerant flows, i.e., a refrigerant flow path, is formed in the space between the recessed portion 340 and the bottom 210a. Thus, the bottom 210a of the module frame 200 can come into contact with the refrigerant.

[0076] The method of manufacturing the recessed portion 340 of the radiator 300 is not particularly limited, but the U-shaped recessed portion 340 having an open upper side can be formed by providing a structure recessed with respect to the plate-shaped radiator 300.

[0077] Meanwhile, although not shown in the figures, a thermally conductive resin layer including a thermally conductive resin can be located Figure 5 between the bottom 210a of the module frame 200 and the battery cell stack 120. The thermally conductive resin layer can be formed by applying the thermally conductive resin to the bottom 210a and curing the applied thermally conductive resin.

[0078] The thermally conductive resin may include a thermally conductive binder material. Specifically, it may include at least one of a silicone resin material, a urethane material, and an acrylic material. The thermally conductive resin is liquid during application but is cured after application, enabling the thermally conductive resin to function to fix one or more battery cells 110 constituting the battery cell stack 120. In addition, since the thermally conductive resin has excellent heat transfer properties, the heat generated from the battery cell 110 can be quickly transferred to the lower side of the battery module.

[0079] The battery module 100 according to the present embodiment can achieve an integrated cooling structure of the module frame 200 and the radiator 300, thereby further improving the cooling performance. The bottom 210a of the module frame 200 can function as the upper plate corresponding to the radiator 300, thereby achieving an integrated cooling structure. Due to direct cooling, the cooling efficiency can be increased, and through the structure in which the radiator 300 is integrated with the bottom 210a of the module frame 200, the space utilization rate on the battery module and the battery pack equipped with the battery module can be further improved.

[0080] Specifically, the heat generated from the battery cell 110 can pass through a thermally conductive resin layer (not shown) located between the battery cell stack 120 and the bottom 210a, the bottom 210a of the module frame 200, and the refrigerant, and then can be transferred to the outside of the battery module 100. By removing unnecessary components according to the conventional cooling structure, the heat transfer path can be simplified, and the air gap between the corresponding layers can be reduced, enabling the cooling efficiency or performance to be improved. In particular, since the bottom 210a is configured as the upper plate of the radiator 300 and the bottom 210a is in contact with the refrigerant, it has the advantage of being able to perform more direct cooling through the refrigerant.

[0081] In addition, by removing unnecessary cooling structures, the height of the battery module 100 is reduced, so the cost can be reduced, and the space utilization rate can be increased. Furthermore, since the battery module 100 can be placed in a compact manner, the capacity or output of the battery pack 1000 including a plurality of battery modules 100 can be increased.

[0082] Meanwhile, the bottom 210a of the module frame 200 can be joined by welding to a part of the lower plate 310 of the radiator 300 where the recess 340 is not formed. In this embodiment, through the integral cooling structure of the bottom 210a of the module frame 200 and the radiator 300, it is possible to achieve the effects of not only improving the above cooling performance but also supporting the load of the battery cell stack 120 accommodated in the module frame 200 and enhancing the rigidity of the battery module 100. In addition, the lower plate 310 and the bottom 210a of the module frame 200 are sealed by welding or the like, so that the refrigerant can flow without leaking into the recess 340 formed inside the lower plate 310.

[0083] For effective cooling, as shown in Figure 5 , the recess 340 is preferably formed over the entire area corresponding to the bottom 210a of the module frame 200. For this purpose, the recess 340 can be bent at least once to connect from one side to the other side. In particular, the recess 340 is preferably bent several times so that the recess 340 is formed over the entire area corresponding to the bottom 210a of the module frame 200. As the refrigerant moves from the starting point to the ending point of the refrigerant flow passage formed over the entire area corresponding to the bottom 210a of the module frame 200, efficient cooling can be performed over the entire area of the battery cell stack 120.

[0084] Meanwhile, the refrigerant is a medium for cooling and is not particularly limited, but the refrigerant can be cooling water.

[0085] Meanwhile, the protruding pattern 340D can be formed in the recess 340 of the radiator 300 according to this embodiment. In the case of a large-area battery module such as the battery cell stack 120 according to this embodiment, compared with the conventional case, the number of stacked battery cells is significantly increased, the width of the refrigerant flow passage may be formed wider, and thus the temperature deviation may be more serious. Compared with the conventional case where about 12 to 24 battery cells are stacked in one battery module, in a large-area battery module, there may be a case where about 32 to 48 battery cells are stacked in one battery module. In this case, the protruding pattern 340D according to this embodiment can achieve the effect of substantially reducing the width of the refrigerant flow passage, so that the pressure drop can be minimized and at the same time the temperature deviation between the widths of the refrigerant flow paths can be reduced. Therefore, a uniform cooling effect can be achieved.

[0086] Next, the fastening by the refrigerant transfer bolt will be described in detail with reference to Figure 6 and Figure 7 .

[0087] Figure 6 is shown in an enlarged mannerFigure 3 Partial perspective view of section “A” of Figure 7 is a partial cross-sectional view of a cross-section taken along Figure 6 cutting line B-B' of

[0088] Refer to Figures 4 to 7 , the battery pack according to the present embodiment includes: a bottom 210a of the module frame 200; and a refrigerant transfer bolt 700 for fastening the radiator 300 and the battery pack frame 1100.

[0089] The battery pack frame 1100 according to the present embodiment may include: battery pack refrigerant pipes 1130 and 1140 for supplying and discharging refrigerant; and refrigerant openings 1150 and 1160 formed in the battery pack refrigerant pipes 1130 and 1140. Specifically, the battery pack refrigerant pipes 1130 and 1140 may include a battery pack refrigerant supply pipe 1130 for supplying refrigerant and a battery pack refrigerant discharge pipe 1140 for discharging refrigerant. The refrigerant openings 1150 and 1160 may include a refrigerant supply opening 1150 connected to the battery pack refrigerant supply pipe 1130 and a refrigerant discharge opening 1160 connected to the battery pack refrigerant discharge pipe 1140.

[0090] The battery pack frame 1100 may include: a support frame 1110 for supporting the battery module 100; and a lower frame 1120 located below the support frame 1110. The battery pack refrigerant supply pipe 1130 and the battery pack refrigerant discharge pipe 1140 may be located between the support frame 1110 and the lower frame 1120. More specifically, the battery pack refrigerant supply pipe 1130 and the battery pack refrigerant discharge pipe 1140 may be configured to be located directly below the support frame 1110 and integrated with the support frame 1110.

[0091] The module frame 200 according to the present embodiment may include a module frame extension 211 formed by extending a part of the bottom 210a of the module frame 200. In addition, the radiator 300 according to the present embodiment may include a radiator extension 311 extending from one side of the radiator 300 to the part where the module frame extension 211 is located. The module frame extension 211 and the radiator extension 311 may have corresponding shapes to each other and may be extended to pass through the end plate 400.

[0092] The first mounting hole 211H may be formed in the module frame extension 211, and the second mounting hole 311H may be formed in the radiator extension 311.

[0093] The refrigerant transfer bolt 700 according to the present embodiment fastens the module frame extension 211, the radiator extension 311, and the battery pack frame 1100. Specifically, the refrigerant transfer bolt 700 sequentially passes through the first mounting hole 211H, the second mounting hole 311H, and the refrigerant supply opening 1150 of the battery pack frame 1100 and is fastened.

[0094] Next, the refrigerant transfer structure through the refrigerant transfer bolt will be described in detail with reference to Figures 8 to 11 etc. In the battery pack refrigerant pipes 1130 and 1140, the battery pack refrigerant supply pipe 1130 will be mainly described, but the refrigerant transfer structure through the refrigerant transfer bolt 700 can be similarly applied to the battery pack refrigerant discharge pipe 1140.

[0095] Figure 8 and Figure 9 is a partial perspective view showing the section “E” in an enlarged manner. Figure 7 Figure 10 a to Figure 10 c are views of the refrigerant transfer bolt according to an embodiment of the present disclosure when observed from various angles. Figure 11 a and Figure 11 b are views of the refrigerant transfer bolt and the opening / closing member according to an embodiment of the present disclosure when observed from various angles.

[0096] Specifically, Figure 8 shows the state in which the refrigerant flow path is opened by the opening / closing member 900a, and Figure 9 shows the state in which the refrigerant flow path is blocked by the opening / closing member 900a. Meanwhile, for convenience of explanation, Figure 10 a to Figure 10 c show the refrigerant transfer bolt 700 in a state in which the opening / closing member 900a is removed, where Figure 10 a is a perspective view of the refrigerant transfer bolt 700, Figure 10 b is a plan view of the refrigerant transfer bolt 700 of Figure 10 a when observed from below, Figure 10 c is a side view of the refrigerant transfer bolt 700 of Figure 10 a when observed from the side after flipping Figure 11 a and Figure 11 b show the state in which the opening / closing member 900a is placed on the refrigerant transfer bolt 700.

[0097] Refer to Figures 8 to 11 ​, a connecting pipe 713 for connecting the refrigerant pipes 1130 and 1140 of the battery pack to the radiator 300 is formed in the refrigerant transfer bolt 700 according to the present embodiment, and the refrigerant transfer bolt 700 includes an opening / closing member 900a that opens or blocks the connecting pipe 713 in response to the temperature of the refrigerant. Figure 8 The connecting pipe 713 of the refrigerant transfer bolt 700 that connects the battery pack refrigerant supply pipe 1130 and the radiator 300 is shown.

[0098] Specifically, the refrigerant transfer bolt 700 may include: a body portion 710 in which the connecting pipe 713 is formed; and a head portion 720 located at the upper end of the body portion 710. Although the columnar structure of the body portion 710 having a diameter corresponding to the inner diameters of the first mounting hole 211H and the second mounting hole 311H is not specifically shown, threads may be formed on the outer peripheral surface. Threads may also be formed on the inner surface of the refrigerant supply opening 1150 so that the body 710 can be fastened to the battery pack frame 1100. The head portion 720 is configured to have a diameter larger than that of the body portion 710 and may bring the module frame extension portion 211 and the radiator extension portion 311 into close contact with each other.

[0099] The refrigerant transfer bolt 700 may include a first opening 711 and a second opening 712 that are connected to the connecting pipe 713 and are formed in the body portion 710. The first opening 711 may be placed inside the battery pack refrigerant supply pipe 1130, and the second opening 712 may be placed between the bottom 210a of the module frame 200 and the radiator 300. The opening direction of the first opening 711 may be parallel to the penetrating direction of the connecting pipe 713, and the opening direction of the second opening 712 may be perpendicular to the penetrating direction of the connecting pipe 713. The first opening 711 may be located at one end of the body portion 710 while being connected to the connecting pipe 713, and a plurality of second openings 712 may be formed along the outer peripheral surface of the body portion 710 and may be connected to the connecting pipe 713.

[0100] The refrigerant that has moved through the battery pack refrigerant supply pipe 1130 sequentially passes through the first opening 711, the connecting pipe 713, and the second opening 712 and flows into the space between the bottom 210a and the radiator 300. As described above, the flowing refrigerant may move along the recessed portion 340 of the radiator 300 to cool the battery module 100.

[0101] The refrigerant transfer bolt 700 according to the present embodiment is not only used to mount and fix the module frame 200 and the radiator 300 to the battery pack frame 1100, but also can be used as a path for supplying refrigerant to the lower end of the battery module 100. Additionally, since the bottom 210a, the radiator 300, and the battery pack refrigerant supply pipe 1130 are strongly and tightly contacted with each other by the fastening force of the refrigerant transfer bolt 700, the sealing property is improved, and the possibility of refrigerant leakage therebetween can be reduced. That is, since installation fixing, pressure sealing, and refrigerant transfer can be performed simultaneously, the number of parts can be reduced and the structure can be simplified. Further, since the refrigerant supply opening 1150 and the second mounting hole 311H are necessarily aligned by the refrigerant transfer bolt 700, the influence of the alignment between the through holes required for supplying refrigerant can be minimized, thereby reducing the possibility of refrigerant leakage.

[0102] Meanwhile, the opening / closing member 900a according to the present embodiment opens or blocks the connection pipe 713 in response to the temperature of the refrigerant. Specifically, the opening / closing member 900a may include a shape memory alloy, and in response to the temperature of the refrigerant, it can adjust the opening and closing of the second opening 712. Additionally, by adjusting the degree of opening and closing, the flow rate of the refrigerant flowing through the radiator 300 can be adjusted. At this time, the shape memory alloy is an alloy that deforms at a transition temperature or lower temperature and has the property of restoring its shape before deformation when the transition temperature is exceeded.

[0103] Specifically, the opening / closing member 900a may include: a blocking portion 910a for opening or blocking the connection pipe 713; and a spring portion 920a connected to the blocking portion 910a and including a shape memory alloy. The blocking portion 910a may have a shape surrounding the outer peripheral surface of the body portion 710 formed with the second opening 712, and the spring-shaped spring portion 920a may be connected below the blocking portion 910a.

[0104] The spring portion 920a may include a shape memory alloy and be capable of deforming in shape in response to the temperature of the refrigerant. In particular, the shape of the spring may expand or contract in the vertical direction according to the temperature of the refrigerant. In response to the shape deformation of the spring portion 920a, the blocking portion 910a may move up and down to open or block the connection pipe 713, particularly the second opening 712. As an example, Figure 8 shows a state where the spring portion 920a contracts in the vertical direction and the blocking portion 910a moves downward to open the second opening 712. Meanwhile, Figure 9 shows a state where the spring portion 920a extends in the vertical direction and the blocking portion 910a moves upward to block the second opening 712.

[0105] Meanwhile, as described above, the battery pack frame 1100 according to the present embodiment may include battery pack refrigerant pipes 1130 and 1140, and refrigerant openings 1150 and 1160 formed in the battery pack refrigerant pipes 1130 and 1140. At this time, the refrigerant openings 1150 and 1160 may include a stepped portion 1150S that supports one end of the spring portion 920a. Refer to Figure 8 and Figure 9 , the refrigerant supply opening 1150 through which the refrigerant transfer bolt 700 passes may include a stepped portion 1150S having a stepped structure. The spring portion 920a may be placed on the upper surface of the stepped portion 1150S. When the spring portion 920a expands or contracts in the vertical direction according to the temperature of the refrigerant, the spring portion 920a is supported by the stepped portion 1150S, and thus, the blocking portion 910a can move up and down.

[0106] By applying the opening / closing member 900a using a shape memory alloy responsive to a predetermined temperature to the refrigerant transfer bolt 700, the battery pack according to the present embodiment can actively adjust the supply and blocking of the refrigerant according to the temperature of the refrigerant, and can also adjust the flow rate of the refrigerant according to the degree of opening and closing. A refrigerant circulation system that adjusts the flow rate according to the temperature of the battery module can be easily formed without requiring a separate complex adjustment device.

[0107] Meanwhile, the battery pack according to the present embodiment may further include a gasket 600 that surrounds the body portion 710 of the refrigerant transfer bolt 700. The gasket 600 may be located in at least one of the following positions: between the head 720 and the module frame extension portion 211; and between the radiator 300 and the battery pack frame 1100. Leakage of the refrigerant can be prevented by the gasket 600.

[0108] Meanwhile, although not specifically shown in the drawings, the first mounting hole 211H, the second mounting hole 311H, and the refrigerant discharge opening 1160 of the battery pack frame 1100 can also be fastened by the refrigerant transfer bolt 700 according to the present embodiment. In other words, according to the present embodiment, the battery pack refrigerant pipes 1130 and 1140 can be connected to the radiator 300 via the refrigerant transfer bolt 700, and the first mounting hole 211H, the second mounting hole 311H, and the refrigerant transfer bolt 700 can be configured in plurality. The refrigerant flowing in from the battery pack refrigerant supply pipe 1130 via any one of the second mounting hole 311H and the refrigerant transfer bolt 700 moves along the recessed portion 340, and then can be discharged to the battery pack refrigerant discharge pipe 1140 via the other second mounting hole 311H and the refrigerant transfer bolt 700.

[0109] Meanwhile, referring again to Figure 11 a and Figure 11 b, the spring portion 920a according to the present embodiment may be a coil spring. Specifically, while such a coil spring surrounds the outer peripheral surface of the body portion 710 of the refrigerant transfer bolt 700, such a coil spring can be deformed by compression or the like in the vertical direction in response to the temperature of the refrigerant.

[0110] Meanwhile, Figure 12 a and Figure 12 b are views of the refrigerant transfer bolt and the opening / closing member according to a modified embodiment of the present disclosure when viewed from various angles.

[0111] Referring to Figure 12 a and Figure 12 b, the opening / closing member 900b according to the present embodiment may include a blocking portion 910b and a spring portion 920b. At this time, the blocking portion 910b may be similar to or the same as the above-described configuration, but the spring portion 920b may be a leaf spring. Specifically, a plurality of leaf springs may be placed at regular intervals along the blocking portion 910b and may be deformed by compression or the like in the vertical direction in response to the temperature of the refrigerant.

[0112] The spring portions 920a and 920b according to the present embodiment as described above may be an exemplary structure, and their shapes are not particularly limited as long as the blocking portions 910a and 910b can move in the vertical direction.

[0113] Next, a fixing method via the fixing bracket will be described in detail with reference to Figure 13 and Figure 14 is a partial cross-sectional view taken along the cutting line C-C' of

[0114] Figure 13 and Figure 6 and Figure 14 is a partial cross-sectional view of a cross-section taken along the cutting line D-D' of Figure 6

[0115] Referring to Figure 4 、 Figure 5 、 Figure 13 and Figure 14 ​, the protrusions 410 are respectively formed on the front and rear surfaces of the battery module 100 according to the present embodiment. The end plates 400 may be located on the front and rear surfaces of the battery module 100, and the protrusions 410 may be formed on the end plates 400. Specifically, the protrusions 410 may have a structure that protrudes in a direction perpendicular to the stacking direction of the battery cells 110 (a direction parallel to the y-axis). That is, the protrusion 410 formed on the front surface of the battery module 100 may protrude in the y-axis direction, and the protrusion 410 formed on the rear surface of the battery module 100 may protrude in the -y-axis direction.

[0116] In addition, the protrusions 410 may be respectively formed at the lower edges of the front surface and the rear surface of the battery module 100. Additionally, two protrusions 410 spaced apart from each other may be formed for each of the front surface and the rear surface of the battery module 100.

[0117] The fixing bracket 500 may be coupled to the battery pack frame 1100 while surrounding the protrusions 410. Specifically, when the protrusions 410 are formed to protrude from the end plates 400, the protrusions 410 have an upper surface and three side surfaces. The fixing bracket 500 may include a fixing portion 510 that wraps the upper surface and one side surface of the protrusion 410. Furthermore, the fixing portion 510 may further wrap the other two side surfaces of the protrusion 410.

[0118] Meanwhile, a bracket hole 500H is formed in the fixing bracket 500, and a battery pack frame hole 1111H is formed in the battery pack frame 1100. The battery pack according to the present embodiment may include: a bracket bolt B1 that passes through the battery pack frame hole 1111H and the bracket hole 500H; and a bracket nut N1 that is coupled to the bracket bolt B1.

[0119] Specifically, the bracket hole 500H and the battery pack frame hole 1111H are positioned to correspond to each other, and the bracket bolt B1 may pass through the battery pack frame hole 1111H and the bracket hole 500H and be able to stand upright. After that, the bracket bolt B1 may be coupled to the bracket nut N1 to fix the fixing bracket 500 to the battery pack frame 1100. For effective fixing, preferably, the battery pack frame hole 1111H, the bracket hole 500H, the bracket bolt B1, and the bracket nut N1 are all configured in plural. In Figure 4 it, an appearance constructed by the above components with a quantity of four each is shown.

[0120] Since the two fixing brackets 500 wrap the protruding portion 410 of the battery module 100 while being coupled to the battery pack frame 1100 by the bracket bolts B1 and the bracket nuts N1, and the two fixing brackets 500 are placed facing each other with the battery module 100 therebetween, the battery module 100 can be received and fixed to the battery pack frame 1100.

[0121] Meanwhile, as shown in Figure 13 , the battery pack according to the present embodiment may further include an insulating member 800 disposed between the protruding portion 410 and the battery pack frame 1100. The insulating member 800 may be a gasket-shaped member exhibiting electrical insulation properties. Electrochemical corrosion may occur due to the contact of dissimilar materials between the end plate 400 and the battery pack frame 1100, but the insulating member 800 can be placed between the end plate 400 and the battery pack frame 1100, thereby preventing the occurrence of electrochemical corrosion.

[0122] Meanwhile, referring back to Figure 6 , the fixing bracket 500 according to the present embodiment may include a cover portion 520 for covering the module frame extension 211. In addition, the fastening structures of the bracket bolts B1 and the bracket nuts N1 may be located on the left and right sides of the cover portion 520, respectively. By forming the cover portion 520 on the fixing bracket 500 fixed with the bracket bolts B1 and the bracket nuts N1, the module frame extension 211 can be squeezed. Accordingly, the module frame extension 211 and the radiator extension 311 are closely attached to each other, so that the possibility of refrigerant leakage therebetween can be reduced. Additionally, the head 720 of the refrigerant transfer bolt 700 can be sealed while being surrounded by the end plate 400, the module frame extension 211, and the cover portion 520. By sealing via the cover portion 520, the leaked refrigerant can be prevented from penetrating into the surrounding portions. That is, the cover portion 520 itself can perform the function of preventing refrigerant leakage.

[0123] Terms representing directions, such as the front side, the rear side, the left side, the right side, the upper side, and the lower side, have been used in the embodiments of the present disclosure, but the terms used are provided only for convenience of description and may vary depending on the position of the object, the position of the observer, and the like.

[0124] One or more battery modules according to the embodiments of the present disclosure described above can be installed together with various control and protection systems, such as a battery management system (BMS) and a cooling system, to form a battery pack.

[0125] The battery module or battery pack can be applied to various devices. For example, the battery module or battery pack can be applied to vehicle devices such as electric bicycles, electric vehicles, and hybrid electric vehicles, and can be applied to various devices that can use secondary batteries, but is not limited thereto.

[0126] The present disclosure has been described in detail with reference to the exemplary embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and modifications and improvements made by those skilled in the art using the basic concepts of the present disclosure defined in the appended claims also fall within the scope of the present disclosure.

[0127] Description of Reference Numerals

[0128] 100: Battery module

[0129] 200: Module frame

[0130] 211: Module frame extension

[0131] 300: Radiator

[0132] 311: Radiator extension

[0133] 700: Refrigerant transfer bolt

[0134] 713: Connection pipe

[0135] 900a, 900b: Open / close member

[0136] 1100: Battery pack frame

Claims

1. A battery pack, comprising: a plurality of battery modules, the plurality of battery modules including: a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a radiator located below the bottom of the module frame; a battery pack frame for accommodating the plurality of battery modules; and a refrigerant transfer bolt for fastening the bottom of the module frame, the radiator, and the battery pack frame, wherein the battery pack frame includes a battery pack refrigerant pipe for supplying and discharging refrigerant, wherein a connection pipe is formed on the refrigerant transfer bolt for connecting the battery pack refrigerant pipe and the radiator, and wherein the refrigerant transfer bolt includes an opening / closing member that opens or blocks the connection pipe in response to the temperature of the refrigerant.

2. The battery pack according to claim 1, wherein: the opening / closing member includes a shape memory alloy and responds to the temperature of the refrigerant.

3. The battery pack according to claim 1, wherein: the refrigerant transfer bolt includes a first opening and a second opening, the first opening and the second opening being connected to the connection pipe, the first opening is placed inside the battery pack refrigerant pipe, the second opening is placed between the bottom of the module frame and the radiator, and the opening / closing member adjusts the opening / closing of the second opening in response to the temperature of the refrigerant.

4. The battery pack according to claim 1, wherein: the opening / closing member includes: a blocking portion for opening or blocking the connection pipe; and a spring portion connected to the blocking portion and including a shape memory alloy.

5. The battery pack according to claim 4, wherein: the spring portion deforms in shape in response to the temperature of the refrigerant, and the blocking portion moves up and down according to the shape deformation of the spring portion to open or block the connection pipe.

6. The battery pack according to claim 4, wherein: the spring portion is a coil spring or a plate spring.

7. The battery pack according to claim 4, wherein: a refrigerant opening is formed in the battery pack frame, and the refrigerant opening includes a stepped portion for supporting one end of the spring portion.

8. The battery pack according to claim 1, wherein: the module frame includes a module frame extension formed by extending a part of the bottom of the module frame, the radiator includes a radiator extension extending from one side of the radiator to the portion where the module frame extension is located, and the refrigerant transfer bolt fastens the module frame extension, the radiator extension, and the battery pack frame.

9. The battery pack according to claim 8, wherein: a refrigerant opening is formed in the battery pack frame, The first mounting hole is formed in the module frame extension portion, the second mounting hole is formed in the radiator extension portion, and the refrigerant transfer bolt passes through the first mounting hole, the second mounting hole, and the refrigerant opening.

10. The battery pack according to claim 1, wherein: the refrigerant transfer bolt includes a first opening and a second opening, and the first opening and the second opening are connected to the connecting pipe, the first opening is placed inside the battery pack refrigerant pipe, the second opening is placed between the bottom of the module frame and the radiator, the opening direction of the first opening is parallel to the penetration direction of the connecting pipe, and the opening direction of the second opening is perpendicular to the penetration direction of the connecting pipe.

11. The battery pack according to claim 1, wherein: the refrigerant transfer bolt includes: a body portion in which the connecting pipe is formed; and a head located at the upper end of the body portion.

12. The battery pack according to claim 11, wherein: the battery pack further includes a washer that surrounds the body portion, and the washer is located in at least one of the following positions: between the head and the module frame extension portion formed by extending a part of the bottom of the module frame; and between the radiator and the battery pack frame.

13. The battery pack according to claim 1, wherein: protrusions are respectively formed on the front surface and the rear surface of the battery module, and the battery pack further includes fixing brackets that are respectively located on the front surface and the rear surface of the battery module, and the fixing brackets are coupled to the battery pack frame while wrapping the protrusions.

14. The battery pack according to claim 1, wherein: the battery pack frame includes: a support frame for supporting the battery module; and a lower frame located below the support frame, and the battery pack refrigerant pipe is located between the support frame and the lower frame.

15. An apparatus including the battery pack according to claim 1.

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