Patent Publication Number: US-2021167466-A1

Title: Battery Module Including Connector Having Bidirectional Coupling Structure

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national phase entry under 35 U. S U.S.C. § 371 of International Application No. PCT/KR2019/017024, filed Dec. 4, 2019, published in Korean, which claims the benefit of priority based on Korean Patent Application No. 10-2018-0155513 filed on Dec. 5, 2018 and Korean Patent Application No. 10-2019-0159240 filed on Dec. 3, 2019 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a battery module, and more particularly, to a battery module in which a module connector connected to an external connector is mounted. 
     BACKGROUND ART 
     Secondary batteries, which are easily applied to various product groups and have electrical characteristics such as high energy density, are universally applied not only for a portable device but also for an electric vehicle (EV) or a hybrid electric vehicle (HEV), an energy storage system or the like, which is driven by an electric driving source. The secondary battery is attracting attention as a new environment-friendly energy source for improving energy efficiency since it gives a primary advantage of remarkably reducing the use of fossil fuels and also does not generate by-products from the use of energy at all. 
     A battery pack for use in electric vehicles has a structure in which a plurality of cell assemblies, each including a plurality of unit cells, are connected in series to obtain a high output. In addition, the unit cell can be repeatedly charged and discharged by electrochemical reactions among components, which include a positive electrode current collector, a negative electrode current collector, a separator, an active material, an electrolyte and the like. 
     Meanwhile, as the need for a large capacity structure is increasing along with the utilization as an energy storage source in recent years, there is a growing demand for a battery pack with a multi-module structure in which a plurality of battery modules, each including a plurality of secondary batteries connected in series and/or in parallel, are integrated. 
     When a plurality of battery cells are connected in series or in parallel to configure a battery pack, it is common to configure a battery module composed of at least one battery cell first, and then configure a battery pack by using at least one battery module and adding other components. The number of battery modules included in the battery pack, or the number of battery cells included in the battery module may be variously set according to the required output voltage or the demanded charge/discharge capacity. 
     The battery module is configured to package battery cells, various electric components and the like in a module case, and further includes a module connector which is connected to an external connector for electrical connection with external devices, etc. outside the module case. The external connector may be, for example, a connector for electrically connecting a plurality of battery modules. 
     In the conventional battery module, the direction of the connector is predetermined for each module. Therefore, there was a need to develop a module with a symmetrical structure according to the predetermined direction of the connector. In this case, all of the same parts were re-developed in a symmetrical form, which resulted in time and cost loss, and increased process complexity. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     Therefore, it is an object of the present disclosure to provide a battery module capable of changing the direction of a module connector as necessary after production of the battery module, by configuring the fastening structure of the module connector mounted on the battery module so that the module connector can be inserted bidirectionally. 
     However, the problem to be solved by the embodiments of the present disclosure is not limited to the above-described problems, and can be variously expanded within the scope of the technical idea included in the present disclosure. 
     Technical Solution 
     A battery module according to an embodiment of the present disclosure includes: a cell assembly including at least one battery cell; a module case accommodating the cell assembly; and a module connector mounted outside the module case, electrically connected to the cell assembly, and configured to connect to an external connector outside the module case. A coupling surface of the module connector may have a first fastening part opened in at least one direction, and a corresponding coupling surface outside the module case may have a second fastening part that is bidirectionally opened so as to be inserted into the first fastening part in a first direction or in a second direction opposite thereto. 
     The first fastening part may be a first slide rail fastening part, and the second fastening part may be a second slide rail fastening part, wherein the first slide rail fastening part and the second slide rail fastening part may be slidably coupled to each other. 
     The second slide rail fastening part may include at least two parallel rail members, and the first slide rail fastening part may include an inner rail member configured to pass between the two rail members of the at least two parallel rail members of the second slide rail fastening part and couple thereto. 
     The two rail members of the at least two parallel rail members of the second slide rail fastening part may have the respective locking protrusions which protrude in directions opposite to each other. 
     The respective locking protrusions of the two rail members may be spaced apart at a distance along an extending direction of the two rail members so that respective centers of the respective locking protrusions are misaligned with each other. 
     The respective locking protrusions may each have an inclined surface inclined to form an obtuse angle with respect to an insertion direction of the module connector. 
     The inner rail member of the first slide rail fastening part may include a hook configured to pass between the two rail members of the at least two parallel rail members of the second slide rail fastening part and couple thereto. 
     The two rail members of the at least two parallel rail members of the second slide rail fastening part may have a first locking protrusion and a second locking protrusion, respectively, which protrude in directions opposite to each other, wherein the first locking protrusion and the second locking protrusion may be spaced apart at a distance along an extending direction of the two rail members so that respective centers of the respective first and second locking protrusions are misaligned with each other, the first locking protrusion may be positioned on a relative right side, and the second locking protrusion may be positioned on a relative left side. 
     Respective outer inclined surfaces of the first locking protrusion and the second locking protrusion facing away from each other may form a steeper inclination angle with respect to the extending direction of the two rail members than respective inner inclined surfaces of the first locking protrusion and the second locking protrusion facing each other. 
     The hook may be bent to one side at an end of the inner rail member, and when the first fastening part is inserted into the second fastening part in the first direction, the hook may be locked to the outer inclined surface of the second locking protrusion. When the first fastening part is inserted into the second fastening part in the second direction, the hook may be locked to the outer inclined surface of the first locking protrusion. 
     The first slide rail fastening part includes at least two outer rail members extending in parallel with the inner rail member, and when the module connector is coupled to the module case, a rail member of the at least two parallel rail members of the second slide rail fastening part may be sandwiched between the outer rail members of the first slide rail fastening part. 
     The module connector may be locked to the corresponding coupling surface outside the module case by inserting the first fastening part into the second fastening part in the first direction. 
     The module connector may be locked to the corresponding coupling surface outside the module case by inserting the first fastening part into the second fastening part in the second direction. 
     The battery module may include a busbar assembly which covers the cell assembly on at least one side of the module case and electrically connects electrode leads of the cell assembly, wherein the busbar assembly includes the second fastening part, and the module connector may be coupled to the busbar assembly. 
     The module connector may be electrically connected to the cell assembly through a flexible printed circuit (FPC) board. 
     The flexible printed circuit board connected to the module connector may extend while being bent in different directions over a plurality of times. 
     According to another embodiment of the present disclosure, there can be provided a battery pack including at least one of the above battery modules and a pack case packaging the at least one battery module. 
     According to still another embodiment of the present disclosure, there can be provided a device including at least one of the battery packs. 
     Advantageous Effects 
     According to the embodiments, a module connector having a fastening structure capable of being inserted and coupled bidirectionally can be applied to a battery module, thereby making it possible to change the direction of the module connector as necessary after production of the battery module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a battery module according to an embodiment of the present disclosure. 
         FIG. 2  is an enlarged perspective view showing a state in which a module connector in a battery module according to an embodiment of the present disclosure is mounted. 
         FIG. 3  is a perspective view showing a module connector of a battery module according to an embodiment of the present disclosure. 
         FIG. 4  is a bottom view showing a module connector of a battery module according to an embodiment of the present disclosure. 
         FIG. 5  is an enlarged perspective view showing a fastening part of a busbar assembly in which a module connector of a battery module according to an embodiment of the present disclosure is mounted. 
         FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 2  and illustrating a first fastening example of a module connector according to an embodiment of the present disclosure. 
         FIG. 7  is a perspective view showing a second fastening example of a module connector according to an embodiment of the present disclosure. 
         FIG. 8  is a cross-sectional view taken along line VIII-VIII of  FIG. 7  and illustrating a second fastening example of a module connector according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     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 may be modified in various different ways, and is not limited to the embodiments set forth herein. 
     Further, throughout the specification, when apart is referred to as “including” a certain component, it means that it can further include other components, without excluding the other components, unless otherwise stated. 
     Further, throughout the specification, when referred to as “planar”, it means when a target portion is viewed from the top, and when referred to as “cross-sectional”, it means when a target portion is viewed from the side of a cross section cut vertically. 
       FIG. 1  is a perspective view showing a battery module according to an embodiment of the present disclosure.  FIG. 2  is an enlarged perspective view showing a state in which a module connector  130  in a battery module according to an embodiment of the present invention is mounted. 
     Referring to  FIGS. 1 and 2 , a battery module  10  according to the present embodiment includes a module connector  130  mounted outside a module case  150  accommodating a cell assembly  100 . Battery cells constituting the cell assembly  100  may be provided as a pouch-type secondary battery, and may be provided by stacking a plurality of battery cells in the cell assembly  100 . The plurality of battery cells may be electrically connected to each other, and each of the battery cells may include an electrode assembly, a battery case accommodating the electrode assembly, and an electrode lead  110  protruding out of the battery case and electrically connected to the electrode assembly. 
     The battery module  10  may include various electric components, and may include, for example, an internal circuit board (ICB) and a battery management system (BMS). Electric components such as the ICB and the BMS board may be electrically connected to the plurality of battery cells. 
     The module case  150  forms the exterior of the battery module  10  and accommodates the cell assembly  100 , wherein a busbar assembly  120  may be coupled to at least one side or both sides of the cell assembly  100  positioned in the direction where the electrode leads  110  of the cell assembly  100  extend, and an insulating frame  160  may be coupled to the outside thereof. The busbar assembly  120  may include a busbar frame  123  disposed to cover the cell assembly  100 , and a busbar fixed to the busbar frame  123 . The busbar frame  123  is made of an insulator and includes a lead slot through which the electrode leads  110  of the cell assembly  100  can pass. The busbar  121  may electrically connect the electrode leads  110  of the cell assembly  100 . 
     Referring to  FIG. 2 , the module connector  130  may be coupled to the busbar assembly  120 , particularly the busbar frame  123 . The module connector  130  has a first fastening part  135  opened in at least one direction on a coupling surface of the lower portion thereof, and the busbar frame  123  has a second fastening part  235  configured on a corresponding coupling surface outside the module case  150  so as to be coupled to the first fastening part  135 . In this embodiment, the first fastening part  135  and the second fastening part  235  may be formed of a slide rail fastening part. In the following, they are referred to as a first slide rail fastening part and a second slide rail fastening part, respectively. However, the present disclosure is not limited to this embodiment, and any module connector having a fastening part with a structure that can be inserted bidirectionally may be included in the scope of the present disclosure. 
     Meanwhile, the battery module  10  may include a flexible printed circuit (FPC) board  140  configured to sense the battery cells inside the module case  150 , and the flexible printed circuit board  140  extends out of the module case  150  and is connected to the module connector  130 . Accordingly, the module connector  130  may be electrically connected to the cell assembly  100  via the flexible printed circuit board  140 . In addition, since the flexible printed circuit board  140  is formed to extend while being bent in different directions over a plurality of times, the degree of freedom in the fastening process may be increased. 
       FIG. 3  is a perspective view showing a module connector of a battery module according to an embodiment of the present disclosure,  FIG. 4  is a bottom view showing a module connector of a battery module according to an embodiment of the present disclosure,  FIG. 5  is an enlarged perspective view showing a fastening part of a busbar assembly in which a module connector of a battery module according to an embodiment of the present disclosure is mounted, and  FIG. 6  is a cross-sectional view taken along line VI-VI of  FIG. 2  and illustrating a first fastening example of a module connector according to an embodiment of the present disclosure. 
     Referring to  FIGS. 3 and 4 , the module connector  130  of the present embodiment has a first slide rail fastening part  135  opened in at least one direction on the coupling surface of the lower portion. Referring to  FIG. 5 , the corresponding coupling surface outside the module case  150 , i.e., the busbar frame  123  of the busbar assembly  120  has a second slide rail fastening part  235  opened bidirectionally. Therefore, the first slide rail fastening part  135  may be coupled to the second slide rail fastening part  235  in a first direction or in a second direction opposite thereto through the opened portion. Thus, the module connector  130  can be coupled to the busbar assembly  120 . In a first fastening example, as shown in  FIG. 6 , the first slide rail fastening part  135  is inserted into the second slide rail fastening part  235  in the first direction (from right to left in  FIG. 6 ), so that it can be locked to the corresponding coupling surface outside the module case  150  of  FIG. 1 . 
     The first slide rail fastening part  135  of the module connector  130  includes three parallel rail members  135   a ,  135   b  and  135   c , and the second slide rail fastening part  235  of the busbar frame  123  includes two parallel rail members  235   a  and  235   b . Among the rail members  135   a ,  135   b  and  135   c  of the first slide rail fastening part  135 , the inner rail member  135   b  may be configured to pass between the two rail members  235   a  and  235   b  of the second slide rail fastening part  235  and couple thereto. 
     The two rail members  235   a  and  235   b  of the second slide rail fastening part  235  may have locking protrusions  236  and  237  which protrude in directions opposite to each other, respectively. These locking protrusions  236  and  237  may have an inclined surface inclined with respect to the insertion direction of the module connector  130 . That is, since the module connector  130  can be inserted into the second slide rail fastening part  235  in the first direction or in the second direction as described above, both the inclined surfaces of the locking protrusions  236  and  237  may be bidirectionally inclined to form an obtuse angle with respect to the extending direction of the rail member. In addition, the locking protrusions  236  and  237  opposite to each other may be spaced apart at a distance along the extending direction of the rail member so that the respective centers are misaligned with each other. Further, inclination angle of the inclined surfaces back to each other (in opposite directions) may be formed more steeply than that of the inclined surfaces facing each other in the pair of locking protrusions  236  and  237 . Here, the inclined surfaces facing each other in the pair of locking protrusions  236  and  237  are referred to as inner inclined surfaces  236   a  and  237   a , and the inclined surfaces back to each other (in opposite direction) are referred to as outer inclined surfaces  236   b  and  237   b . That is, the outer inclined surfaces  236   b  and  237   b  in the pair of locking protrusions  236  and  237  can respectively forma steeper inclined angle with respect to the extending direction of the rail members  235   a  and  235   b  than each of the inner inclined surfaces  236   a  and  237   a.    
     Specifically, in the first locking protrusions  236  positioned relatively on the right side among the locking protrusions  236  and  237  where the centers are misaligned with each other, the inclination angle of the outer inclined surface  236   b  may be formed more steeply than that of the inner inclined surface  236   a , and in the second locking protrusions  237  positioned relatively on the left side among the locking protrusions  236  and  237  where the centers are misaligned with each other, the inclination angle of the outer inclined surface  237   b  may be formed more steeply than that of the inner inclined surface  237   a.    
     Meanwhile, the inner rail member  135   b  of the first slide rail fastening part  135  is a hook-type rail member configured to pass between the two rail members  235   a  and  235   b  of the second slide rail fastening part  235  and lock thereto. The end of the hook-type rail member includes a hook  136  which is bent to one side, and the other side opposite to the hook  136  may be chamfered. Therefore, when the module connector  130  is coupled, the inner rail member  135   b  of the first slide rail fastening part  135  passes between the two rail members  235   a ,  235   b  of the second slide rail fastening part  235  and, thus, the hook  136  may sequentially pass through two locking protrusions  236  and  237  and be locked. 
     Specifically, when the first slide rail fastening part  135  is inserted in the first direction (from right to left as viewed in  FIG. 6 ), the hook  136  may pass though the inner inclined surface  237   a  of the second locking protrusion  237  located on the left side and then locked to the outer inclined surface  237   b  of the second locking protrusion  237 . The inner inclined surface  237   a  forms a relatively gradual inclination angle and, therefore, is easy for the hook  136  to pass through, and the outer inclined surface  237   b  forms a relatively steep inclination angle, so the hook  136  can be firmly locked thereto. 
     In addition, since the side opposite to the hook  136  is chamfered, it can easily pass through the outer inclined surface  236   b  of the first locking protrusion  236  located on the right side. 
     The first slide rail fastening part  135  of the module connector  130  may include two outer rail members  135   a  and  135   c  extending in parallel with the inner rail member  135   b . When the module connector  130  is coupled, the rail members  235   a  and  235   b  of the second slide rail fastening part  235  may be sandwiched between the outer rail members  135   a  and  135   c  of the first slide rail fastening part  135 . 
       FIG. 7  is a perspective view showing a second fastening example of a module connector according to an embodiment of the present disclosure, and  FIG. 8  is a cross-sectional view taken along line VIII-VIII of  FIG. 7  and illustrating the second fastening example of a module connector according to an embodiment of the present disclosure. 
     Referring to  FIGS. 7 and 8 , the first slide rail fastening part  135  is inserted into the second slide rail fastening part  235  in a second direction (from left to right as viewed in  FIG. 8 ), so that the module connector  130  can be locked to the corresponding coupling surface outside the module case  150  of  FIG. 1 . That is, as described above, the module connector  130  may be fastened to the second slide rail fastening part  235  formed on the busbar frame  123  via the first slide rail fastening part  135 . However, in the second fastening example, it is inserted and fastened from the opposite direction to the first fastening example. In this case, since the flexible printed circuit board  140  extending from the cell assembly  100  is formed to extend while being bent in different directions over a plurality of times, it can be stretched and connected according to the changed direction of the module connector  130 . 
     In addition, even when the hook  136  of the inner rail member  135   b  of the first slide rail fastening part  135  formed in the module case  150  is inserted in the second direction, it may be locked by sequentially passing through two locking protrusions  236  and  237  formed on the rail members  235   a  and  235   b  of the second slide rail fastening part  235 . 
     Specifically, when the first slide rail fastening part  135  is inserted in the second direction (from left to right as viewed in  FIG. 8 ), the hook  136  passes through the inner inclined surface  236   a  of the first locking protrusion  236  located on the right side, and then may be locked to the outer inclined surface  236   b  of the first locking protrusion  236 . The inner inclined surface  236   a  forms a relatively gradual inclination angle and, thus, is easy for the hook  136  to pass through, and the outer inclined surface  236   b  forms a relatively steep inclination angle, so that the hook  136  can be firmly locked thereto. 
     Moreover, since the side opposite to the hook  136  is chamfered, it can easily pass through the outer inclined surface  237   b  of the second locking protrusion  237  located on the left side. 
     In addition, the outer rail members  135   a  and  135   c  of the first slide rail fastening part  135  are defined outside the rail members  235   a  and  235   b  of the second slide rail fastening part  235  so that the latter members can be sandwiched between the former members. 
     Thus, according to the embodiment of the present disclosure, the connector, which has a fastening structure in which it can be inserted and coupled bidirectionally, can be applied to a battery module, thereby making it possible to change the direction of the module connector as necessary after production of the battery module. 
     In particular, as described above, through the hook  136  of the inner rail member  135   b  and the pair of locking protrusions  236  and  237  having their respective outer inclined surfaces  236   b  and  237   b  forming a steeper inclination angle compared to the inner inclined surfaces  236   a  and  237   a , it is possible to implement both the bidirectional insertion of the module connector  130  and the firm coupling upon insertion. 
     Meanwhile, one or more of the battery modules according to an embodiment of the present disclosure may be packaged in a pack case to form a battery pack. 
     The battery module as described above and the battery pack including the same can be applied to various devices. Such devices include, but are not limited to, transportation means such as an electric bicycle, an electric vehicle, and a hybrid vehicle, and the present disclosure is applicable to various devices capable of using any battery module and any battery pack including the same, which belongs to the scope of the invention. 
     Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present disclosure defined in the following claims also belong to the scope of rights. 
     DESCRIPTION OF REFERENCE NUMERALS AND SYMBOLS 
     
         
         
           
               10 : battery module 
               100 : cell assembly 
               110 : electrode lead 
               120 : busbar assembly 
               121 : busbar 
               123 : busbar frame 
               130 : module connector 
               135 : first slide fastening part 
               135   a ,  135   c : outer rail member of first slide fastening part 
               135   b : inner rail member of first slide fastening part 
               136 : hook 
               140 : flexible printed circuit board 
               150 : module case 
               235 : second slide rail fastening part 
               235   a ,  235   b : rail member of the second slide rail fastening part 
               236 ,  237 : locking protrusion