Patent Publication Number: US-2023143366-A1

Title: Battery Module, And Battery Pack And Vehicle Comprising Battery Module

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/KR2020/012796 filed on Sep. 22, 2020, which claims priority from Korean Patent Application No. 10-2019-0132947 filed on Oct. 24, 2019 in the Republic of Korea, the disclosures 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. 
     BACKGROUND ART 
     Secondary batteries which are highly applicable to various products and exhibit superior electrical properties such as high energy density, etc. are commonly used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electrical power sources. The secondary battery is drawing attention as a new energy source for enhancing environment friendliness and energy efficiency in that the use of fossil fuels can be reduced greatly and no byproduct is generated during energy consumption. 
     Secondary batteries widely used at present include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries and the like. An operating voltage of the unit secondary battery cell, namely a unit battery cell, is about 2.5V to 4.5V. Therefore, if a higher output voltage is required, a plurality of battery cells may be connected in series to configure a battery pack. In addition, depending on the charge/discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to configure a battery pack. Thus, the number of battery cells included in the battery pack may vary according to the required output voltage or the required charge/discharge capacity. 
     Meanwhile, 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 including at least one battery cell first, and then configure a battery pack by using at least one battery module and adding other components. 
     In the case of a conventional battery module, an electrode lead of a battery cell and a sensing bus bar of a bus bar assembly are closely pressed by using a welding jig so that the electrode lead and the sensing bus bar are welded by laser welding or the like. When welding the electrode lead of the conventional battery cell and the sensing bus bar of the bus bar assembly, a protrusion step difference may occur between the electrode lead and the sensing bus bar due to an assembly tolerance of the bus bar assembly or the like. In the conventional battery module, if the welding process is performed in a state where the protrusion step difference occurs, welding defects may be more likely to occur. 
     In the conventional art, when pressing the electrode lead and the sensing bus bar using a pressing jig or the like in order to compensate for the protrusion step difference, in the conventional battery module, generally, the sensing bus bar is mounted in a state of being fixed to a bus bar frame of the bus bar assembly. Thus, the relatively movable electrode lead side is intensively pressed, which may cause a damage to the electrode lead. 
     Therefore, there is a demand to develop a battery module which may prevent the electrode lead from being damaged while welding and connecting an electrode lead of at least one battery cell and a sensing bus bar of the bus bar assembly and also prevent welding quality from deteriorating even if a protrusion step difference is formed due to an assembly tolerance, and also to provide a battery pack and a vehicle including the battery module. 
     DISCLOSURE 
     Technical Problem 
     Therefore, the present disclosure is directed to providing a battery module which may prevent an electrode lead from being damaged when an electrode lead of at least one battery cell and a sensing bus bar of a bus bar assembly are welded and connected, and a battery pack and a vehicle including the battery module. 
     In addition, the present disclosure is also directed to providing a battery module, which may prevent welding quality from deteriorating even if a protrusion step difference is formed due to an assembly tolerance when the electrode lead of at least one battery cell and the sensing bus bar of the bus bar assembly are welded and connected, and a battery pack and a vehicle including the battery module. 
     Moreover, the present disclosure is also directed to providing a battery module, which may prevent the electrode lead from being damaged when cell swelling occurs at battery cells, 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 plurality of battery cells having electrode leads configured to protrude on at least one side thereof; and a bus bar assembly configured to electrically connect the electrode leads of the plurality of battery cells, wherein the bus bar assembly includes: a bus bar frame configured to cover at least one side of the plurality of battery cells; a plurality of lead slots defined by the bus bar frame so that the electrode leads pass therethrough; at least one sensing bus bar disposed between the plurality of lead slots and connected to the electrode leads; and at least one elastic guider configured to elastically support the at least one sensing bus bar and disposed at the rear of the at least one sensing bus bar in a front and rear direction of the bus bar frame. 
     The at least one sensing bus bar may be configured to be movable along the front and rear direction of the bus bar frame while elastically contacting the at least one elastic guider. 
     The at least one elastic guider may include a first leaf spring coupled to the bus bar frame and configured to be elastically deformable in the front and rear direction of the bus bar frame; and a second leaf spring coupled to the bus bar frame to be spaced apart from the first leaf spring by a predetermined distance and configured to be elastically deformable in the front and rear direction of the bus bar frame. 
     The at least one elastic guider may include a spring connection portion provided to the bus bar frame and configured to connect the first leaf spring and the second leaf spring. 
     The spring connection portion may be configured to be in contact with a rear surface of the at least one sensing bus bar. 
     The at least one elastic guider may be formed integrally with the bus bar frame. 
     The bus bar assembly may include an anti-separation stopper coupled to the bus bar frame and configured to prevent the at least one sensing bus bar from being separated from the bus bar frame. 
     The anti-separation stopper may include a stopper hook provided above the at least one sensing bus bar and configured to limit a movement of a top end of the at least one sensing bus bar over a predetermined distance when the at least one sensing bus bar moves forward; and a stopper groove provided below the at least one sensing bus bar and configured to limit a movement of a bottom end of the at least one sensing bus bar over a predetermined distance when the at least one sensing bus bar moves forward. 
     In addition, the present disclosure further provides a battery pack, comprising: at least one battery module according to the above embodiments; and a pack case configured to package the at least one battery module. 
     Moreover, the present disclosure further provides a vehicle, comprising at least one battery pack according to the above embodiments. 
     Advantageous Effects 
     According to various embodiments as above, it is possible to provide a battery module which may prevent an electrode lead from being damaged when an electrode lead of at least one battery cell and a sensing bus bar of a bus bar assembly are welded and connected, and a battery pack and a vehicle including the battery module. 
     In addition, according to various embodiments as described below, it is possible to provide a battery module which may prevent welding quality from deteriorating even if a protrusion step difference is formed due to an assembly tolerance when the electrode lead of at least one battery cell and the sensing bus bar of the bus bar assembly are welded and connected, and a battery pack and a vehicle including the battery module. 
     Moreover, according to various embodiments as above, it is possible to provide a battery module which may prevent the electrode lead from being damaged when cell swelling occurs at battery cells, and a battery pack and a vehicle including the battery module. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawing. 
         FIG.  1    is a diagram for illustrating a battery module according to an embodiment of the present disclosure. 
         FIG.  2    is a diagram for illustrating a main part of the battery module of  FIG.  1   . 
         FIG.  3    is a diagram for illustrating a bus bar frame, from which a sensing bus bar of a bus bar assembly of  FIG.  2    is excluded. 
         FIG.  4    is a diagram for illustrating an anti-separation stopper according to another embodiment of the present disclosure of  FIG.  1   . 
         FIGS.  5  and  6    are diagrams for illustrating a step difference correction between electrode leads and a sensing bus bar using an elastic guider when the electrode leads of the battery cells of the battery module of  FIG.  1    and the sensing bus bar are welded. 
         FIGS.  7  and  8    are diagrams for illustrating that the damage to the electrode lead is prevented using the elastic guider when cell swelling occurs at the battery cells of the battery module of  FIG.  1   . 
         FIG.  9    is a diagram for illustrating a battery pack according to an embodiment of the present disclosure. 
         FIG.  10    is a diagram for illustrating a vehicle according to an embodiment of the present disclosure. 
     
    
    
     BEST MODE 
     The present disclosure will become more apparent by describing in detail the embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the embodiments disclosed herein are illustrative only for better understanding of the present disclosure, and that the present disclosure may be modified in various ways. In addition, for ease understanding of the present disclosure, the accompanying drawings are not drawn to real scale, but the dimensions of some components may be exaggerated. 
       FIG.  1    is a diagram for illustrating a battery module according to an embodiment of the present disclosure,  FIG.  2    is a diagram for illustrating a main part of the battery module of  FIG.  1   , and  FIG.  3    is a diagram for illustrating a bus bar frame, from which a sensing bus bar of a bus bar assembly of  FIG.  2    is excluded. 
     Referring to  FIGS.  1  to  3   , a battery module  10  may include a battery cell  100  and a bus bar assembly  200 . 
     The battery cell  100  is a secondary battery and may be provided as a pouch-type secondary battery, a rectangular secondary battery or a cylindrical secondary battery. Hereinafter, in this embodiment, it will be described that the battery cell  100  is provided as a pouch-type secondary battery. 
     There may be a plurality of battery cells  100 . The plurality of battery cells  100  are stacked to be electrically connected to each other, and electrode leads  150  may protrude on at least one side of each thereof. 
     The bus bar assembly  200  is provided for electrically connecting the electrode leads  150  of the plurality of battery cells  100 , and may be disposed at one side of the plurality of battery cells  100 . 
     The bus bar assembly  200  may include a bus bar frame  210 , a lead slot  220 , a sensing bus bar  230 , an elastic guider  240 , and an anti-separation stopper  250 . 
     The bus bar frame  210  may cover at least one side of the plurality of battery cells  100 . To this end, the bus bar frame  210  may be sized and shaped to cover at least one side of the plurality of battery cells  100 . 
     The lead slot  220  is defined by the bus bar frame  210  and may allow the electrode leads  150  of the plurality of battery cells  100  to pass therethrough. There may be a plurality of lead slots  220 , wherein each of the plurality of electrode leads  150  may pass through each of the plurality of lead slots  220 . 
     The sensing bus bar  230  is disposed between the plurality of lead slots  220  and may be connected to the electrode leads  150  of the battery cells  100 . There may be a plurality of sensing bus bars  230 . Hereinafter, in this embodiment, it will be described that there are a plurality of sensing bus bars  230 . 
     The plurality of sensing bus bars  230  may be passing through the lead slots  220  and connected with the electrode leads  150  of the plurality of battery cells  100  by welding such as laser welding. Here, the electrode leads  150  may be welded to the sensing bus bar  230  in a non-bending manner where the electrode leads  150  are not bent. 
     The elastic guider  240  may elastically support the sensing bus bar  230  and may be disposed at the rear of the sensing bus bar  230  in a front and rear directions of the bus bar frame  210 . 
     There may be plurality of elastic guiders  240  to correspond to the number of the sensing bus bars  230 . The elastic guider  240  may be formed integrally with the bus bar frame  210 . 
     By means of the elastic guider  240 , the plurality of sensing bus bars  230  may be provided to be movable along the front and rear direction of the bus bar frame  210  while elastically contacting the elastic guider  240 . 
     The elastic guider  240  may include a first leaf spring  242 , a second leaf spring  244 , and a spring connection portion  246 . 
     The first leaf spring  242  may be coupled to the bus bar frame  210 . The first leaf spring  242  may be elastically deformable in the front and rear direction of the bus bar frame  210 . 
     The second leaf spring  244  may be coupled to the bus bar frame  210  spaced apart from the first leaf spring  210  by a predetermined distance. The second leaf spring  244  may be elastically deformable in the front and rear direction of the bus bar frame  210 , like the first leaf spring  242 . 
     The spring connection portion  246  is coupled to the bus bar frame  210  and may connect the first leaf spring  242  and the second leaf spring  244 . The spring connection portion  246  may be in contact with a rear surface of the sensing bus bar  230 . 
     The anti-separation stopper  250  is coupled to the bus bar frame  210 , and may prevent the sensing bus bar  230  from being separated from the bus bar frame  210  when the sensing bus bar  230  moves forward and backward. 
     The anti-separation stopper  250  may include a stopper hook  252  and a stopper groove  254 . 
     The stopper hook  252  is positioned above the sensing bus bar  230  and may limit a movement of a top end of the sensing bus bar  230  over a predetermined distance when the sensing bus bar  230  moves forward. 
     The stopper groove  254  is positioned below the sensing bus bar  230  and may limit a movement of a bottom end of the sensing bus bar  230  over a predetermined distance when the sensing bus bar  230  moves forward. 
       FIG.  4    is a diagram for illustrating an anti-separation stopper according to another embodiment of the present disclosure of  FIG.  1   . 
     Referring to  FIG.  4   , the bus bar assembly  205  may include the stopper hook  252  in a pair. The pair of stopper hooks  252  may be positioned at upper and lower sides of the sensing bus bar  230 , respectively, to more effectively prevent the sensing bus bar  230  from being separated when the sensing bus bar  230  moves forward. 
     Hereinafter, a detailed operation of the elastic guider  240  of the bus bar assembly  200  of the battery module  10  according to this embodiment will be described in more detail. 
       FIGS.  5  and  6    are diagrams for illustrating a step difference correction between electrode leads and a sensing bus bar using an elastic guider when the electrode leads of the battery cells of the battery module of  FIG.  1    and the sensing bus bar are welded. 
     First, the upper and lower direction of  FIGS.  5  and  6    may correspond to the front and rear direction of  FIGS.  2  to  4   . That is, the upper direction of  FIGS.  5  and  6    may be the front direction of  FIGS.  2  to  4   , and the lower direction of  FIGS.  5  and  6    may be the rear direction of  FIGS.  2  to  4   . Hereinafter, the upper direction in  FIGS.  5  and  6    will be described as a front direction, and the lower direction in  FIGS.  5  and  6    will be described as a rear direction. 
     Referring to  FIGS.  5  and  6   , in the battery module  10 , when the battery cells  100  and the bus bar assembly  200  are assembled, a predetermined step difference may occur between the electrode leads  150  of the battery cells  100  and the sensing bus bar  230  of the bus bar assembly  200  due to an assembly tolerance or the like. 
     For example, the sensing bus bar  230  of the bus bar assembly  200  may protrude forward further from the electrode leads  150  of the battery cells  100 . To correct this protrusion step difference, a worker or the like may press the protruding sensing bus bar  230  downward using a pressing jig J. 
     In this embodiment, since the sensing bus bar  230  is elastically movable in the front and rear direction of the bus bar frame  210  by means of the elastic guider  240 , when the pressing jig J is pressed downward, the bus bar frame  210  may move rearward. 
     After that, in order to correct the step difference between the sensing bus bar  230  and the electrode leads  150 , the worker or the like may connect the electrode leads  150  and the sensing bus bar  230  to each other by welding, such as laser welding. 
     In this embodiment, when the pressing jig J is pressed downward, the sensing bus bar  230  is elastically movable in the front and rear direction by means of the elastic guider  240 . Therefore, when the pressing jig J is pressed for correcting the step difference, a load and stress applied to the electrode leads  150  of the battery cells  100  may be minimized. 
     Accordingly, in this embodiment, damage to the electrode leads  150  of the battery cells  100  that may occur when correcting the step difference of the pressing jig J may be effectively prevented. 
     As described above, the battery module  10  according to this embodiment may prevent the electrode lead  150  from being damaged when welding and connecting the electrode lead  150  of the battery cell  100  and the sensing bus bar  230  of the bus bar assembly  200 , and also may effectively prevent the welding quality from deteriorating even though a protrusion step difference occurs due to an assembly tolerance or the like. 
       FIGS.  7  and  8    are diagrams for illustrating that the damage to the electrode lead is prevented using the elastic guider when cell swelling occurs at the battery cells of the battery module of  FIG.  1   . 
     In  FIGS.  7  and  8   , the upper direction will be described as a front direction and the lower direction will be described as a rear direction, like  FIGS.  5  and  6   . 
     Referring to  FIGS.  7  and  8   , in the battery module  10 , the battery cells  100  may expand in a thickness direction due to an abnormal situation caused by overheating of the battery cells  100 . That is, the battery cells  100  may expand in a left and right direction according to cell swelling. 
     In this embodiment, when cell swelling occurs at the battery cells  100 , through the elastic guider  240 , the sensing bus bar  230  and the ends of the electrode leads  150  welded to the sensing bus bar  230  may move elastically rearward (in a lower direction in  FIG.  8   ). 
     As the sensing bus bar  230  and the ends of the electrode leads  150  welded to the sensing bus bar  230  move backward, the length of the electrode leads  150  tending to increase due to cell swelling of the battery cells  100  may be compensated. 
     Therefore, when cell swelling occurs in the battery cells  100 , the battery module  10  according to this embodiment may minimize a tensile stress applied to the electrode leads  150  to effectively prevent the electrode leads  150  from being damaged due to the tensile stress. 
       FIG.  9    is a diagram for illustrating a battery pack according to an embodiment of the present disclosure, and  FIG.  10    is a diagram for illustrating a vehicle according to an embodiment of the present disclosure. 
     Referring to  FIGS.  9  and  10   , a battery pack  1  may include at least one battery module  10  and a pack case  50  for packaging the at least one battery module  10  according to the above-described embodiment. 
     The battery pack  1  may be provided to a vehicle V as a fuel source of the vehicle. As an example, the battery pack  1  may be provided to an electric vehicle, a hybrid electric vehicle, and various other-type vehicles V capable of using the battery pack  1  as a fuel source. 
     In addition, the battery pack  1  may be provided in other devices, instruments or facilities such as an energy storage system using a secondary battery, in addition to the vehicle V. 
     As described above, the battery pack  1  of this embodiment and devices, instruments or facilities such as the vehicle, which have the battery pack  1 , include the battery module  10  as described above, and thus it is possible to implement a battery pack  1  having all the advantages of the battery module  10  described above, or devices, instruments, facilities or the like such as the vehicle V, which have the battery pack  1 . 
     According to various embodiments as above, it is possible to provide a battery module  10  which may prevent an electrode lead  150  from being damaged when an electrode lead  150  of at least one battery cell  100  and a sensing bus bar  230  of a bus bar assembly  200 ,  205  are welded and connected, and a battery pack  1  and a vehicle V including the battery module  10 . 
     In addition, according to various embodiments as described above, it is possible to provide a battery module  10 , which may prevent welding quality from deteriorating even if a protrusion step difference is formed due to an assembly tolerance when the electrode lead  150  of at least one battery cell  100  and the sensing bus bar  230  of the bus bar assembly  200 ,  205  are welded and connected, and a battery pack  1  and a vehicle V including the battery module  10 . 
     Moreover, according to various embodiments as described above, it is possible to provide a battery module  10 , which may prevent the electrode lead  150  from being damaged when cell swelling occurs at battery cells  100 , and a battery pack  1  and a vehicle V including the battery module  10 . 
     While the embodiments of the present disclosure have been shown and described, it should be understood that the present disclosure is not limited to the specific embodiments described, and that various changes and modifications can be made within the scope of the present disclosure by those skilled in the art, and these modifications should not be understood individually from the technical ideas and views of the present disclosure.