Patent Publication Number: US-2022223931-A1

Title: Battery Module, and Battery Pack and Vehicle Comprising Same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2020/009560 filed Jul. 20, 2020, published in Korean, which claims priority from Korean Patent Application No. 10-2019-0155856 filed Nov. 28, 2019, all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a battery module, and a battery pack and a vehicle including the battery module, and more particular, to a battery module, which may cool a circuit board through an expansion hole extending from a mounting hole, and a battery pack and a vehicle including the battery module. 
     BACKGROUND ART 
     As technology development and demand for a mobile device have increased, demand for a secondary battery as an energy source has rapidly increased. Conventionally, a nickel-cadmium battery or a hydrogen ion battery has been used as the secondary battery. However, a lithium secondary battery is recently widely used because charging and discharging is free due to rare memory effect in comparison with a nickel-based secondary battery, a self-discharge rate is very low, and an energy density is high. 
     The lithium secondary battery mainly uses a lithium oxide and a carbonaceous material as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, respectively coated with the positive electrode active material and the negative electrode active material, are arranged with a separator therebetween, and an exterior, that is a battery case, which seals and receives the electrode assembly together with an electrolyte solution. 
     The lithium secondary battery includes a positive electrode, a negative electrode, and a separator interposed therebetween and an electrolyte. Depending on which material is used for the positive electrode active material and the negative electrode active material, the lithium secondary battery is classified into a lithium ion battery (LIB) and a polymer lithium ion battery (PLIB). Generally, an electrode of the lithium secondary battery is prepared by applying the positive or negative electrode active material to a current collector made of aluminum or copper sheet, mesh, film, foil, or the like and then drying the same. 
     A battery module may be configured by stacking secondary batteries, namely battery cells, and the battery module may include a bus bar, a relay, a circuit board, and the like to electrically connect the battery cells and sense and control temperature. 
     Here, the circuit board is coupled to the case using a fastening member or the like, and a mounting hole for coupling the circuit board to the case is formed in the circuit board. 
       FIG. 1  is a diagram schematically showing a circuit module of a conventional battery module.  FIG. 1  corresponds to FIG. 4 of Korean Unexamined Patent Publication No. 10-2015-0089481 (hereinafter, referred to as a prior literature). 
     Referring to  FIG. 1 , a via hole  2  is formed in a printed circuit board  1 . Seeing the prior literature, if a secondary battery protection circuit module including at least one via hole  2  vertically perforated in the printed circuit board  1  is used, an abnormal heating state and an abnormal temperature state of the protection circuit module may be accurately detected. 
     Here, referring to  FIG. 1 , since a fuse  3  closes the via hole  2  entirely, air may not flow through the via hole  2 . In other words, in the prior literature, the via hole  2  is not intended to allow air to flow therethrough, but it is intended that an abnormal heating state is accurately detected through the via hole  2  so that the fuse  3  is quickly destroyed. 
     Therefore, in the prior literature, although the electrical connection may be cut by means of the fuse  3  when the temperature of the printed circuit board  1  rises, it is not possible to cool the printed circuit board  1  through the via hole  2  when the temperature of the printed circuit board  1  rises. 
     SUMMARY 
     Technical Problem 
     The present disclosure is directed to providing a battery module, which may cool a circuit board when the temperature of the circuit board rises, and a battery pack and a vehicle including the battery module. 
     Technical Solution 
     In one aspect of the present disclosure, there is provided a battery module, comprising: a battery cell stack in which a plurality of battery cells are stacked; a case configured to accommodate the battery cell stack; a circuit board disposed at the case; a mounting hole formed in the circuit board and configured to receive a fastening member therein to fix the circuit board to the case; and an expansion hole formed in the circuit board and extending from the mounting hole. 
     Also, the expansion hole may be a perforated hole formed to perforate an area of the circuit board around the mounting hole entirely. 
     In addition, the fastening member may be a screw, and the mounting hole and expansion hole may be configured such that, when a screw body of the screw is inserted into and fastened to the mounting hole, at least a part of the expansion hole may be not covered by a screw head of the screw. 
     Also, the battery module may include a plurality of expansion holes that extend radially from the mounting hole. 
     In addition, the expansion hole may include: a first hole portion extending from the mounting hole; and a second hole portion extending from the first hole and having a different width than the first hole. 
     Also, the first hole portion may be formed to have a smaller width than the second hole portion. 
     In addition, a length direction of the expansion hole extends radially from the mounting hole, the first hole portion may have a smaller length than the second hole portion in the length direction. 
     Also, an outer edge of the first hole portion may be positioned radially inward from an outer edge of the screw head and an outer edge of the second hole portion is positioned radially outward from the outer edge of the screw head. 
     Also, the battery module may further include the fastening member. 
     In addition, the battery module may further include a plurality of mounting holes, each mounting hole including one or more corresponding expansion holes. 
     Also, the battery module may include a mounting hole and one or more corresponding expansion holes at each corner of the circuit board. 
     In addition, the expansion hole may be configured to permit air to flow therethrough while the circuit board is fixed to the case by the fastening member. 
     Meanwhile, in another aspect the present disclosure, there is also provided a battery pack, comprising the battery module described in any of the embodiments herein, and a vehicle, comprising the battery module described in any of the embodiments herein. 
     Advantageous Effects 
     In the embodiments of the present disclosure, since an expansion hole extending from the mounting hole is formed, when the temperature of the circuit board rises, the circuit board may be cooled by air flowing through the expansion hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically showing a circuit module of a conventional battery module. 
         FIG. 2  is an exploded perspective view schematically showing a battery module according to an embodiment of the present disclosure. 
         FIG. 3  is a plan view showing a circuit board of the battery module according to an embodiment of the present disclosure. 
         FIG. 4  is a diagram observed along the line A-A of  FIG. 3 . 
         FIG. 5  is a diagram observed along the line B-B of  FIG. 3 . 
         FIG. 6  is a diagram showing a modified embodiment of an expansion hole in the battery module according to an embodiment of the present disclosure. 
         FIG. 7  is a diagram showing another modified embodiment of the expansion hole in the battery module according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure. 
     In the drawings, the size of each element or a specific part of the element may be exaggerated, omitted, or schematically illustrated for convenience and clarity of a description. Thus, the size of each element does not entirely reflect the actual size of the element. A detailed description of well-known functions or elements associated with the present disclosure will be omitted if it unnecessarily obscures the subject matter of the present disclosure. 
     The term, ‘coupling’ or ‘connecting’ as used herein, may refer not only to a case where one member and another member are directly combined or directly connected but also a case where one member is indirectly combined with another member via a connecting member or is indirectly connected. 
       FIG. 2  is an exploded perspective view schematically showing a battery module according to an embodiment of the present disclosure,  FIG. 3  is a plan view showing a circuit board of the battery module according to an embodiment of the present disclosure,  FIG. 4  is a diagram observed along the line A-A of  FIG. 3 ,  FIG. 5  is a diagram observed along the line B-B of  FIG. 3 ,  FIG. 6  is a diagram showing a modified embodiment of an expansion hole in the battery module according to an embodiment of the present disclosure, and  FIG. 7  is a diagram showing another modified embodiment of the expansion hole in the battery module according to an embodiment of the present disclosure. 
     Referring to the drawings, a battery module  10  according to an embodiment of the present disclosure includes a battery cell stack  100 , a case  200 , a circuit board  300 , a mounting hole  400 , and an expansion hole  600 . 
     The battery cell stack  100  may include a plurality of battery cells  110  provided with electrode leads. The electrode lead provided to the battery cell  110  is a kind of terminal exposed to the outside and connected to an external device and may be made of a conductive material. The electrode lead may include a positive electrode lead and a negative electrode lead. The positive electrode lead and the negative electrode lead may be disposed at opposite sides of the battery cell  110  in the longitudinal direction, or the positive electrode lead and the negative electrode lead may be disposed at the same side of the battery cell  110  in the longitudinal direction. The electrode lead may be electrically coupled to a bus bar. The battery cell  110  may have a structure in which a plurality of unit cells, in each of which a positive electrode plate, a separator and a negative electrode plate are arranged in order, or a plurality of bi-cells, in each of which a positive electrode plate, a separator, a negative electrode plate, a separator, a positive electrode plate, a separator and a negative electrode plate are arranged in order, are stacked suitable for a battery capacity. 
     The battery cell stack  100  may be configured such that a plurality of battery cells  110  are stacked on each other. Here, the battery cell  110  may have various structures, and the plurality of battery cells  110  may be stacked in various ways. 
     The battery cell stack  100  may include a plurality of cartridges (not shown) for respectively accommodating the battery cells  110 . Each cartridge (not shown) may be manufactured by injection-molding plastic, and a plurality of cartridges (not shown), each having an accommodation portion capable of storing the battery cell  110 , may be stacked. A cartridge assembly in which the plurality of cartridges (not shown) are stacked may have a connector element or a terminal element. The connector element may include, for example, various types of electrical connection parts or members for connection to a battery management system (BMS) that may provide data on voltage or temperature of the battery cell  110 . In addition, the terminal element includes a positive terminal and a negative terminal as main terminals connected to the battery cell  110 , and the terminal element may have a terminal bolt to be electrically connected to the outside. Meanwhile, the battery cell  110  may have various shapes. 
     The case  200  is configured to accommodate the battery cell stack  100 . Here, the case  200  may be configured to surround the battery cell stack  100 . That is, in the case  200 , the battery cell stack  100  or the cartridge assembly accommodating the battery cell stack  100  may be stored. That is, the case  200  surrounds the battery cell stack  100  or the plurality of cartridge assemblies entirely, thereby protecting the battery cell stack  100  or the cartridge assemblies from external vibration or impact. 
     The case  200  may be shaped corresponding to the shape of the battery cell stack  100  or the cartridge assembly. For example, if the battery cell stack  100  or the cartridge assembly is provided in a hexahedral shape, the case  200  may also be provided in a hexahedral shape to correspond thereto. 
     The case  200  may be manufactured by, for example, bending a metal plate, or using an injection-molded plastic. In addition, the case  200  may be manufactured as an integral type, or may be manufactured as a separable type. 
     The case  200  may have a perforated portion (not shown) formed therein so that the connector element or the terminal element may be exposed therethrough to the outside. That is, the connector element or the terminal element may be electrically connected to a predetermined external component or member, and the perforated portion may be formed in the case  200  so that the electrical connection is not disturbed by the case  200 . 
     The case  200  may include an upper case  210 , a lower case  220 , and a side case  230 , but is not limited thereto. 
     The circuit board  300  is disposed at and coupled to the case  200 . The circuit board  300  may be coupled to the case  200  at various locations. Referring to  FIG. 2 , the circuit board  300  is coupled to the upper case  210 , but this is an example and the present disclosure is not limited thereto. If the circuit board  300  is coupled to the upper case  210 , a housing (not shown) for protecting the case  200  may be further provided. 
     The mounting hole  400  is formed in the circuit board  300  so that the fastening member  500  is inserted therein to fix the circuit board  300 . The mounting hole  400  may be provided in various ways, and, for example, the mounting hole  400  may be provided as a circular hole. 
     In addition, the fastening member  500  may also be provided in various ways, but hereinafter, it will be described that the fastening member  500  is a screw  510 . In addition, a thread may be formed at the circuit board  300  so as to be fastened to the screw  510 , but the thread of the circuit board  300  is not shown in the drawings. The screw  510  may include a screw body  511  and a screw head  512 . The screw body  511  is inserted into the mounting hole  400  of the circuit board  300  to fix the circuit board  300 . The screw head  512  is coupled to the screw body  511 . 
     Referring to  FIG. 3 , the expansion hole  600  extends from the mounting hole  400 . In addition, referring to  FIG. 5 , the expansion hole  600  is provided as a perforated hole to perforate the circuit board  300  entirely. Here, referring to  FIGS. 3 and 5 , when the screw body  511  described above is inserted into the mounting hole  400  and fastened thereto, at least a part of the expansion hole  600  is located out of the screw head  512 . 
     If the expansion hole  600  extending from the mounting hole  400  is located out of the screw head  512  in this way, air may flow through the expansion hole  600  as shown in  FIG. 5 . That is, the air flowing by convection may move through the expansion hole  600  (see an arrow X in  FIG. 5 ) and cool the circuit board  300  with a high temperature. 
     Referring to  FIG. 3 , the expansion hole  600  may be provided in plural, and the plurality of expansion holes  600  may be formed to extend radially from the mounting hole  400 . The plurality of expansion holes  600  are formed radially even in modified embodiments of  FIGS. 6 and 7 , explained later. However, the plurality of expansion holes  600  are not necessarily arranged radially. 
     Referring to  FIG. 6 , which is a modified embodiment of the expansion hole  600 , the expansion hole  600  may include a first hole  610  and a second hole  620 . Here, the first hole  610  may be a hole extending from the mounting hole  400 , the second hole  620  may be a hole extending from the first hole  610 , and the first hole  610  and the second hole  620  may be formed to have different widths. 
     For example, as shown in  FIG. 6 , the width of the first hole  610  may be smaller than the width of the second hole  620 . As shown in  FIG. 3 , in the case where the overall width of the expansion hole  600  is the same, if the width of the expansion hole  600  is too large, the total area of the thread of the circuit board  300  fastened to the screw body  511  decreases, so the fastening rigidity of the screw body  511  may be reduced. Meanwhile, if the width of the expansion hole  600  is too small for the fastening rigidity of the screw body  511 , air may not flow smoothly. 
     In this consideration, the expansion hole  600  is configured to include the first hole  610  and the second hole  620  with different widths. Also, for the fastening rigidity of the screw body  511 , the first hole  610  is formed to have a smaller width than the second hole  620 , and, for smooth air flow, the second hole  620  is formed to have a larger width than the first hole  610 . 
     That is, in  FIG. 6 , in order to increase the area of the portion (see a portion P in  FIG. 6 ) of the circuit board  300  that is fastened to the screw body  511 , the width of the first hole  610  is formed relatively smaller than the width of the second hole  620  to increase the fastening rigidity of the screw body  511  and the circuit board  300 . 
     However, if there is no serious problem in the fastening rigidity of the screw  510  and the air flow, the expansion hole  600  having the same width as shown in  FIG. 3 , which is easy to manufacture, may be used. 
     In addition, based on a longitudinal direction extending radially from the mounting hole  400  (refer to an arrow Y in  FIG. 6 ), the first hole  610  may be formed to have a smaller length than the second hole  620 . Since the width of the first hole  610  is smaller than the width of the second hole  620  as described above, as the length of the second hole  620  is longer, the flow space through which air may flow is widened. 
     In  FIG. 6 , a part of the second hole  620  is covered by the screw head  512 , but a perforated hole is formed in a lower part of the screw head  512  by the second hole  620 , so air may flow through the perforated hole. Thus, even though a part of the second hole  620  is covered by the screw head  512 , air may flow smoothly. 
     Therefore, if the second hole  620  is formed to have a larger length than the first hole  610 , the amount of air flow increases, thereby increasing the cooling efficiency. 
     Referring to  FIG. 7 , which is another modified embodiment of the expansion hole  600 , the first hole  610  of the expansion hole  600  is formed to have a smaller width than the second hole  620 , so that based on an edge of the screw head  512 , the first hole  610  is disposed inner than the edge of the screw head  512  and the second hole  620  is disposed outer than the edge of screw head  512 .  FIG. 7  shows an embodiment in which the fastening rigidity of the screw body  511  is more important, compared to  FIG. 6 . 
     Hereinafter, the operations and effects of the battery module  10  according to an embodiment of the present disclosure will be described with reference to the drawings. 
     The screw  510  is inserted through the mounting hole  400  formed in the circuit board  300  to fix the circuit board  300  to the case  200 . Here, the expansion hole  600  is formed to extend from the mounting hole  400 , where an upper side of the mounting hole  400  is blocked by the screw head  512  but at least part of the expansion hole  600  is located out of the screw head  512 , thereby securing an opened state. 
     In addition, since the expansion hole  600  is provided as a perforated hole that perforates the circuit board  300  entirely, air may flow through the opened expansion hole  600  and cool the circuit board  300 . 
     Meanwhile, the first hole  610  extends from the mounting hole  400 , the second hole  620  extends from the first hole  610 , and the first hole  610  may be formed to have a smaller width than the second hole  620 . In addition, based on a longitudinal direction extending radially from the mounting hole  400 , the first hole  610  may be formed to have a smaller length than the second hole  620 . 
     With this configuration, the screw body  511  may be fastened to the circuit board  300  to have sufficient rigidity, and also the circuit board  300  may be effectively cooled. 
     Meanwhile, a battery pack (not shown) according to an embodiment of the present disclosure may include at least one battery module  10  according to an embodiment of the present disclosure. Also, in addition to the battery modules  10 , the battery pack (not shown) may further includes a case for accommodating the battery modules  10 , and various devices for controlling charge and discharge of the battery modules  10 , such as a BMS, a current sensor, a fuse, and the like. 
     Meanwhile, a vehicle (not shown) according to an embodiment of the present disclosure may include the battery module  10  or the battery pack (not shown) described above, and the battery pack (not shown) may include the battery module  10 . In addition, the battery module  10  according to an embodiment of the present disclosure may be applied to the vehicle (not shown), for example a predetermined vehicle (not shown) provided to use electricity such as an electric vehicle or a hybrid electric vehicle. 
     The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure relates to a battery module, and a battery pack and a vehicle including the battery module, and may be used in industries related to batteries.