Patent Publication Number: US-2022223961-A1

Title: Battery pack

Description:
TECHNICAL FIELD 
     The present disclosure relates to a battery pack. 
     BACKGROUND ART 
     In general, a secondary battery is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Secondary batteries are used as energy sources for mobile devices, electric vehicles, hybrid vehicles, electric bicycles, uninterruptible power supply, and the like. The secondary batteries may be used in the form of a single battery depending on the type of external device to be applied, or may be used in the form of a module in which a plurality of batteries are connected and bundled as a unit. 
     Small mobile appliances such as cell phones can be operated for a certain period of time with the power and capacity of a single battery. However, In the case of appliances that require long-term driving and high-power driving, such as electric vehicles and hybrid vehicles that consume a lot of power, due to the problem of power and capacity, a module type battery including a plurality of batteries is preferred, and an output voltage or an output current can be increased according to the number of built-in batteries. 
     DESCRIPTION OF EMBODIMENTS 
     Technical Problem 
     An embodiment of the present disclosure provides a battery pack having improved driving stability and advantageous in light reduction. 
     An embodiment of the present disclosure provides a battery pack in which the structure of an insulating adhesive tape interposed between adjacent battery cells is improved, thereby preventing defects caused when the insulating adhesive tape is cut or attached. 
     Solution to Problem 
     In order to solve the above problems, a battery back of the present disclosure includes 
     a plurality of battery cells; and 
     an insulating adhesive tape interposed between the battery cells adjacent to each other; 
     wherein the insulating adhesive tape includes 
     an insulating film; and 
     at least one double-sided adhesive film attached between the insulating film and the battery cell and extending along one direction, 
     wherein a plurality of cut lines are formed in the double-sided adhesive film. 
     Advantageous Effects of Disclosure 
     According to the present disclosure, there can be provided a battery pack in which adjacent battery cells are insulated from each other and structurally bonded to each other, thereby improving driving stability and enabling weigh reduction, and can be provided a battery pack in which cutting defects caused in the process of individually cutting a continuously supplied insulating adhesive tape can be prevented, a work for attaching the insulating adhesive tape can be easily performed by preventing the crumples or wrinkles of the insulating adhesive tape, and adhesion force between battery cells can be maintained firmly. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a perspective view of a battery pack according to an embodiment of the present disclosure. 
         FIG. 2  shows an exploded perspective view of the battery pack shown in  FIG. 1 . 
         FIG. 3  shows an exploded perspective view of a part of the battery pack shown in  FIG. 2 . 
         FIGS. 4 and 5  show a planar structure and a cross-sectional structure of the insulating adhesive tape shown in  FIG. 3 , respectively. 
         FIG. 6  shows a view for explaining a structure of a cut line of a double-sided adhesive film. 
         FIG. 7  is a view showing a modified embodiment of the double-sided adhesive film shown in  FIG. 6 . 
     
    
    
     BEST MODE 
     A battery back of the present disclosure includes 
     a plurality of battery cells; and 
     an insulating adhesive tape interposed between the battery cells adjacent to each other; 
     wherein the insulating adhesive tape includes 
     an insulating film; and 
     at least one double-sided adhesive film attached between the insulating film and the battery cell and extending along one direction, 
     wherein a plurality of cut lines are formed in the double-sided adhesive film. 
     For example, the cut lines may be formed on a straight line extending obliquely along an oblique direction with respect to a width direction of the double-sided adhesive film. 
     For example, the cut lines may extend at a constant inclination angle with respect to a width direction of the double-sided adhesive film. 
     For example, the cut lines may be formed at a regular pitch interval along a length direction of the double-sided adhesive film. 
     For example, the pitch interval may be set in a range of 20 mm to 30 mm. 
     For example, a shortest distance between the cut lines adjacent to each other in a length direction of the double-sided adhesive film may have a value greater than at least 0. 
     For example, the shortest distance between the cut lines adjacent to each other may be set in a range of 10 mm to 15 mm. 
     For example, the cut line may include first and second ends opposite to each other along a width direction of the double-sided adhesive film, and 
     the shortest distance between the cut lines adjacent to each other may correspond to a distance between the first and second ends opposite to each other. 
     For example, the cut lines may be formed at a regular pitch interval along the length direction of the double-sided adhesive film, and 
     the shortest distance between the cut lines adjacent to each other may be formed to be a half of the pitch interval. 
     For example, the cut line may include first and second ends opposite to each other along a width direction of the double-sided adhesive film, and 
     the pitch interval may correspond to a distance between the same first ends or second ends of the cut lines adjacent to each other. 
     For example, the cut line may be limitedly formed over a cut thickness corresponding to a part of a total thickness of the double-sided adhesive film. 
     For example, an attachment area of the double-sided adhesive film attached to the insulating film may be smaller than an area of the insulating film. 
     For example, the double-sided adhesive film may be formed in a stripe pattern extending along one direction crossing the insulating film. 
     For example, the double-sided adhesive film may extend along a height direction of the battery cell. 
     For example, the double-sided adhesive film may be formed in pairs spaced apart from each other along a width direction of the battery cell. 
     For example, along an arrangement direction of the battery cells, the double-sided adhesive film may be attached to front and back surfaces of the insulating film, respectively. 
     MODE OF DISCLOSURE 
     Hereinafter, a battery pack according to a preferred embodiment of the present disclosure will be described with reference to the accompanying drawings. 
       FIG. 1  shows a perspective view of a battery pack according to an embodiment of the present disclosure.  FIG. 2  shows an exploded perspective view of the battery pack shown in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the battery pack may include a plurality of battery cells C, a bus bar  200  for electrically connecting the plurality of battery cells C, and a bus bar holder  150  for providing electrical insulation between the bus bar  200  and the battery cells C. 
     The battery cell (C) may include an electrode assembly (not shown) and a case  10  for accommodating the electrode assembly (not shown), and first and second electrode terminals  11  and  12  electrically connected to different electrode plates of an electrode assembly (not shown) may be formed on the case  10 . The first and second electrode terminals  11  and  12  may be assembled on the case  10 , and any one of the first and second electrode terminals  11  and  12 , for example, the first electrode terminal  11  may form a conductive connection with the case  10  and may have the same polarity as the case  10 . In this case, the first electrode terminal  11  may be omitted, and the case  10  may serve as the first electrode terminal  11 . Meanwhile, the second electrode terminal  12  may form an insulating connection with the case  10 . 
     The bus bar  200  may connect a pair of adjacent battery cells C in parallel with the same polarity, and may connect a pair of adjacent battery cells C in parallel with each other to form a parallel module PM. The bus bar  200  may connect a pair of parallelly connected battery cells C (parallel module PM) and another pair of parallelly connected battery cells C (another parallel module PM) in series with opposite polarities. The bus bar  200  may electrically connect a pair of parallelly connected battery cells C (parallel module PM) and another pair of parallelly connected battery cells C (another parallel module PM) in series, but a pair of battery cells C (parallel module PM) and another pair of battery cells C (another parallel module PM), which are connected by the bus bar  200 , may not be adjacent to each other. As such, first and second output terminals  501  and  502  of the battery pack may be concentrated at any one side of the battery pack through a manner in which the bus bar  200  connects non-adjacent battery cells C, that is, non-adjacent parallel modules PM in series. 
     The bus bar holder  150  may provide insulation between the battery cell C and the bus bar  200 , and may include a terminal hole  150 ′ for allowing coupling between the first and second electrode terminals  11  and  12  formed in the battery cell C and the bus bar  200 . A positioning rib R for aligning the assembly position of the bus bar  200  may be formed around the terminal hole  150 ′ of the bus bar holder  150 . 
       FIG. 3  shows an exploded perspective view of a part of the battery pack shown in  FIG. 2 .  FIGS. 4 and 5  show a planar structure and a cross-sectional structure of the insulating adhesive tape shown in  FIG. 3 , respectively. 
     Referring to  FIG. 3 , referring to  FIG. 3 , an insulating adhesive tape  100  may be interposed between a plurality of battery cells C arranged in a row. The insulating adhesive tape  100  may serve to block the electrical interference and thermal interference between adjacent battery cells C. For example, the case  10  of the battery cell C may have an electrical polarity, and may have the same polarity as one electrode plate of an electrode assembly (not shown). In this case, the insulating adhesive tape  100  may be interposed between the neighboring battery cells C to block electrical interference therebetween. 
     The insulating adhesive tape  100  may structurally couple adjacent battery cells C to each other and bind a plurality of battery cells C to form a single pack. For example, in an embodiment of the present disclosure, the plurality of battery cells C for forming a battery pack may be coupled to each other through the insulating adhesive tape  100 , and a separate binding structure for binding the plurality of battery cells C may be omitted. That is, as a binding structure for combining the plurality of battery cells C into one pack, a plurality of metal plates surrounding a row of battery cells C, for example, an end plate (not shown) and a side plate (not shown) need not be applied, and thus these metal plates may be omitted. As such, a low-weight battery pack may be provided by binding the plurality of battery cells C in the form of one pack through the insulating adhesive tape  100 , and the volume and weigh of the battery pack may be reduced by omitting the binding structure made of a metal material. 
     The insulating adhesive tape  100  is interposed between adjacent battery cells C, and may be disposed in a central region of the battery cells C. The battery cell C may experience swelling in which volume expands according to charging and discharging operations, and in this case, swelling may be concentrated in the central region of the battery cell C rather than the edge of the battery cell C where the bending or warping of the case  10 , which may limit the swelling, is formed. In this case, the insulating adhesive tape  100  may be placed in the central region of the battery cell C, thereby blocking electrical interference and thermal interference between adjacent battery cells C that may be deformed in a direction approaching each other according to swelling. In an embodiment of the present disclosure, the insulating adhesive tape  100  may be placed over most of the region of the battery cell C, including the central region of the battery cell C. 
     The insulating adhesive tape  100  may include an insulating film  110  and a double-sided adhesive film  120  attached to the insulating film  110 . The insulating film  110  may be made of an insulating material to provide electrical insulation and thermal insulation between adjacent battery cells C, and may be formed in a size sufficient to cover most of the region of the battery cell C, including the central region of the battery cell C. For example, the insulating film  110  may be formed in the shape of a rectangular sheet, and may be made of a ceramic material such as MICA. 
     The double-sided adhesive film  120  may have adhesive properties on both surfaces thereof, that is, one surface and the other surface thereof so as to attach the insulating film  110  to the battery cell C. That is, one surface of the double-sided adhesive film  120  may be attached to the insulating film  110 , and the other surface thereof may be attached to the battery cell C. The double-sided adhesive film  120  is limitedly attached to a part of the insulating film  110 , and may not be attached over most of the region of the insulating film  110 . That is, the attachment area between the insulating film  110  and the double-sided adhesive film  120  may be at least smaller than the total area of the insulating film  110 . 
     The double-sided adhesive film  120  may be formed in an area sufficient to provide adhesion between the insulating film  110  and the battery cell C. When the double-sided adhesive film  120  is formed in an excessive area, the insulating film  110  may be wrinkled or crumpled, and thus the attachment area of the double-sided adhesive film  120  is preferably limited to an appropriate level. 
     If the double-sided adhesive film  120  is excessively attached over most of the region of the insulating film  110 , the insulating film  110  may be wrinkled or crumpled, and thus a work for attaching the insulating adhesive tape  100  may be difficult. For example, with respect to the formation of the insulating adhesive tape  100 , the insulating adhesive tape  100  is formed by attaching the double-sided adhesive film  120  onto the flat insulating film  110 , and the insulating adhesive tape  100  formed in this way may be delivered by being wound in the form of a roll. Then, the insulating adhesive tape  100  delivered in the form of a roll may be transported in one direction with transition from a state of being wound around an unroller, to a state of being flattened again, cut individually to a predetermined size, and then attached between the battery cells C. As such, the insulating adhesive tape  100  repeats bending in the form of a roll and flattening, and in the attachment area between the insulating film  110  and the double-sided adhesive film  120  that are stickily attached to each other, stress may be accumulated to such an extent that movement therebetween is limited. In this case, when the attachment area of the double-sided adhesive film  120  is formed in an excessive area exceeding an appropriate level, the double-sided adhesive film  120  restricts the movement of the insulating film  110  and the causes the crumples or wrinkles of the insulating film  110 . 
     In an embodiment of the present disclosure, the double-sided adhesive film  120  may be formed in a stripe pattern extending along one direction crossing the insulating film  110 , and may include a pair of double-sided adhesive films  120  extending in parallel with each other. More specifically, the double-sided adhesive film  120  may be formed in a stripe pattern along the height direction Z 2  of the battery cell C, and may be formed as a pair so as to be spaced apart from each other along the width direction Z 3  of the battery cell C. In this embodiment, the length direction Z 2  of the double-sided adhesive film  120  may correspond to the height direction Z 2  of the battery cell C, and the width direction Z 3  of the double-sided adhesive film  120  may correspond to the width direction Z 3  of the battery cell C. Throughout the present specification, the height direction Z 2  of the battery cell C may refer to a direction facing an electrode surface of the battery cell C in which the first and second electrode terminals  11  and  12  are formed, and the width direction Z 3  of the battery cell C may refer to a direction in which the first and second electrode terminals  11  and  12  face each other. The height direction Z 2  of the battery cell C and the width direction Z 3  of the battery cell C may correspond to directions perpendicular to each other. 
     The double-sided adhesive film  120  may be formed in pairs spaced apart from each other along the width direction Z 3  of the battery cell C, thereby providing a balanced adhesion between the battery cell C and the insulating film  110 . In this case, the double-sided adhesive films  120  may be respectively formed on the front and back surfaces of the insulating film  110  along the arrangement direction Z 1  of the battery cells C, so that the front battery cell (C) and the rear battery cell (C) may be attached to each other, and the battery cells C adjacent to each other in the front and rear directions may be firmly attached to each other through the double-sided adhesive films  120  formed in pairs at balanced positions along the width direction Z 3  of the battery cells C. Throughout the present specification, the front-rear direction may refer to an arrangement direction Z 1  in which the battery cells C are arranged. 
     The double-sided adhesive films  120  are formed in pairs spaced apart from each other along the width direction Z 3  of the battery cell C, thereby providing an extra space capable of absorbing the volume expansion of swelling concentrated in the central region of the battery cell C. Meanwhile, in another embodiment of the present disclosure, the double-sided adhesive films  120  may be formed in a stripe pattern along the width direction Z 3  of the battery cell C, and may also be formed in a pair so as to be spaced apart from each other along the height direction Z 2  of the battery cell C. In this embodiment, the length direction Z 3  of the double-sided adhesive film  120  may correspond to the width direction Z 3  of the battery cell C, and the width direction Z 2  of the double-sided adhesive film  120  may correspond to the height direction Z 2  of the battery cell C. 
     Cut lines  121  may be formed in the double-sided adhesive film  120 . The cut lines  121  may allow relative deformation or positional movement between the double-sided adhesive film  120  and the insulating film  110 , thereby relieving the stress between the double-sided adhesive film  120  and the insulating film  110  and thus preventing the crumples or wrinkles of the insulating film  110 . 
     As described above, with respect to the formation of the insulating adhesive tape  100 , the insulating adhesive tape  100  is formed by attaching the double-sided adhesive film  120  onto the flat insulating film  110 , and the insulating adhesive tape  100  formed in this way may be delivered by being wound in the form of a roll. Then, the insulating adhesive tape  100  delivered in the form of a roll may be transported in one direction with transition from a state of being wound around an unroller, to a state of being flattened again, cut individually to a predetermined size, and then attached between the battery cells C. In this case, the double-sided adhesive film  120  attached to the flat insulating film  110  may cause the crumples or wrinkles of the insulating film  110  while being wound in a roll form, and in contrast, the double-sided adhesive film  120  may cause the crumples or wrinkles of the insulating film  110  while the insulating adhesive tape  100  wound around an unroller in a roll form spreading out again in a flat state. That is, the insulating adhesive tape  100  repeats bending in the form of a roll and flattening, and in this case, as the movement between the insulating film  110  and the double-sided adhesive film  120 , which are attached to each other in a sticky manner, is restricted, stress may accumulate between the insulating film  110  and the double-sided adhesive film  120 , and the accumulation of stress may cause the crumple or wrinkle of the insulating film  110 . 
     In the present disclosure, since the cut lines  121  are formed in the double-sided adhesive film  120 , relative deformation or positional movement between the double-sided adhesive film  120  and the insulating film  110  may be allowed, thereby relieving the stress between the double-sided adhesive film  120  and the insulating film  110  and thus preventing the crumples or wrinkles of the insulating film  110  due to the accumulation of stress. 
     Referring to  FIG. 5 , the cut line  121  may be limitedly formed only to a cut thickness Tc corresponding to a part of the total thickness T of the double-sided adhesive film  120 , and may not be formed to the remaining thickness Tr. That is, the remaining thickness Tr may include an intact double-sided adhesive film  120  in which the cut line  121  is not formed. If the cut line  121  is formed over the entire thickness T of the double-sided adhesive film  120 , since the double-sided adhesive film  120  is separated by a unit of the cut line  121 , in the process of attaching the double-sided adhesive film  120 , it is necessary to individually attach each piece of the double-sided adhesive film  120  separated by the cut line  121  to each piece without performing a continuous work, and there is a concern about the detachment of the torn double-sided adhesive film even after the attachment of the double-sided adhesive film  120 , so that the cut line  121  to be formed in the double-sided adhesive film  120  may be limitedly formed only to the cut thickness Tc, which is a part of the total thickness T of the double-sided adhesive film  120 , for the efficiency of the attachment operation and the strong attachment of the double-sided adhesive film  120 . For example, of the total thickness T of the double-sided adhesive film  120 , the remaining thickness Tr of the double-sided adhesive film  120  having an intact form, to which the cut line  121  is not formed and the double-sided adhesive film  120  is not cut, may be formed to be 0.1 mm or more. If the residual thickness Tr of the double-sided adhesive film  120  is formed to be less than 0.1 mm, the double-sided adhesive film  120  may be separated by a unit of the cut line  121  even with a small shock or vibration. 
     Meanwhile, the cut line  121  of the double-sided adhesive film  120  is for relieving the stress between the double-sided adhesive film  120  and the insulating film  110  by allowing the relative deformation or positional movement between the double-sided adhesive film  120  and the insulating film  110 , it is preferred that the cut thickness Tc of the cut line is formed to a sufficient thickness. When the cut thickness Tc of the cut line  121  is formed too thin, it may not be sufficient to relieve the stress between the double-sided adhesive film  120  and the insulating film  110  and it may be difficult to prevent the insulating film  110  from being wrinkled. 
       FIG. 6  shows a view for explaining a structure of a cut line of a double-sided adhesive film. 
     Referring to  FIG. 6 , a plurality of cut lines  121  may be formed with a pitch interval P therebetween in the length direction Z 2  of the double-sided adhesive film  120 . For example, the cut lines  121  may be formed at a constant pitch interval P along the length direction Z 2  of the double-sided adhesive film  120 . The cut line  121  may include first and second ends  121   a  and  121   b  opposite to each other along the width direction Z 3  of the double-sided adhesive film  120 , and the pitch interval P may correspond to a distance between the same first ends  121   a  of the first and second cut lines  1211  and  1212  adjacent to each other or a distance between the same second ends  121   b  of the first and second cut lines  1211  and  1212  adjacent to each other. Throughout the present specification, the width direction Z 3  of the double-sided adhesive film  120  may refer to a direction perpendicular to the length direction Z 2  of the double-sided adhesive film  120 . For example, in an embodiment of the present disclosure, the length direction Z 2  and the width direction Z 3  of the double-sided adhesive film  120  may correspond to the height direction Z 2  and the width direction Z 3  of the battery cell C, respectively. 
     With respect to the setting of the pitch interval P, it is preferred that the first cut line  1211  and the second cut line  1212  adjacent to each other along the longitudinal direction Z 2  of the double-sided adhesive film  120  are spaced apart from each other with a sufficient pitch interval P so as not to overlap each other along the width direction Z 3  of the double-sided adhesive film  120 . For example, it is preferred that the first and second cut lines  1211  and  1212  are spaced apart from each other with a sufficient pitch interval P therebetween such that the projections (hatched regions in  FIG. 6 ) of the first and second cut lines  1211  and  1212  do not overlap each other along the width direction Z 3  of the double-sided adhesive film  120 . In an embodiment of the present disclosure, the pitch interval P may be set within the range of 20 mm to 30 mm. It is preferred that the pitch interval P between the cut lines  121  adjacent to each other is set in relation to the shortest distance D between the cut lines  121  adjacent to each other, which will be described later. 
     It is preferred that the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other along the length direction Z 2  of the double-sided adhesive film  120  (or the shortest distance D between the neighboring cut lines  121 ) is formed to have a value greater than at least 0 (zero). The first and second cut lines  1211  and  1212  may extend obliquely at a constant inclination angle θ along the width direction Z 3  of the double-sided adhesive film  120 . In this case, the shortest distance D between the first and second cut lines  1211  and  1212  along the length direction Z 2  of the double-sided adhesive film  120  (or the shortest distance D between neighboring cut lines  121 ) may correspond to a distance between the first and second ends  121   a  and  121   b  opposite to each other along the width direction Z 3  among the first and second cut lines  1211  and  1212 . 
     More specifically, the shortest distance D between the first and second cut lines  1211  and  1212  (or the shortest distance D between neighboring cut lines  121 ) may correspond to a distance from the second end  121   b  of the first cut line  1211  to the first end  121   a  of the second cut line  1212  along the length direction Z 2  of the double-sided adhesive film  120 . Here, the second end  121   b  of the first cut line  1211  and the first end  121   a  of the second cut line  1212  are ends adjacent to each other along the length direction Z 2  of the double-sided adhesive film  120 , and the distance therebetween may correspond to the shortest distance D between the first and second cut lines  1211  and  1212 . Contrary, the first end  121   a  of the first cut line  1211  and the second end  121   b  of the second cut line  1212  are ends arranged away from each other in the length direction Z 2  of the double-sided adhesive film  120 , and the distance therebetween may correspond to the longest distance between the first and second cut lines  1211  and  1212 , but does not correspond to the shortest distance D. 
     As described above, unlike the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other, the pitch interval P of the first and second cut lines  1211  and  1212  (or the pitch interval P of the cut line  121 ) may correspond to a distance between the same first ends  121   a  or second ends  121   b  of the first and second cut lines  1211  and  1212  along the width direction Z 3 . 
     In order to separate the continuously formed insulating adhesive tape  100  (or double-sided adhesive film  120 ) individually, the shortest distance D between the first and second cut lines  1211  and  1212  may form an clearance width of a cutting path B through which a cutting blade passes in the width direction Z 3  of the double-sided adhesive film  120 . That is, the insulating adhesive tape  100  (or the double-sided adhesive film  120 ) may be individually cut to an appropriate size along the length direction Z 2  and attached to the battery cell C. In this case, if the cutting path B and the cut line  121  are in contact with each other, some pieces of the double-sided adhesive film  120  are detached from the double-sided adhesive film  120  while the cutting path B and the cut-out line  121  are in contact with each other, so that an adhesion gap may occur. Accordingly, in the present disclosure, it is preferable to sufficiently secure the clearance width, that is, the shortest distance (D) between the first and second cut lines  1211  and  1212 , such that the cutting path B and the cut line  121  do not come into contact with each other. 
     Referring to  FIG. 6 , in an embodiment of the present disclosure, the shortest distance D between the first and second cut lines  1211  and  1212  (or the shortest distance D between neighboring cut lines  121 ) may correspond to an extra length remaining by excluding the projections (hatched areas in  FIG. 6 ) of the first and second cut lines  1211  and  1212  from the pitch interval P of the first and second cut lines  1211  and  1212  (or the pitch interval of the cut line  121 ). If the cutting path B of the cutting blade passing in the width direction Z 3  is formed inside the projection (hatched area in  FIG. 6 ) of the first and second cut lines  1211  and  1212  in order to cut the insulating adhesive tape  100  or the double-sided adhesive film  120  individually, the double-sided adhesive film  120  is fragmented as the cutting path B and the first and second cut lines  1211  and  1212  come into contact with each other. Therefore, it is preferred that the cutting pass B passes through the extra length remaining by excluding the projections (hatched areas in  FIG. 6 ) of the first and second cut lines  1211  and  1212  from the pitch interval P of the first and second cut lines  1211  and  1212  (or the pitch interval of the cut line  121 ) or passes through the shortest distance D between the second cut lines  1211  and  1212 . 
     In an embodiment of the present invention, the shortest distance D between the first and second cut lines  1211  and  1212 , that is, the clearance width of the cutting path B may be set to about half of the pitch interval P of the first and second cut lines  1211  and  1212 . As described above, as the shortest distance D between the first and second cut lines  1211  and  1212  set to about half the pitch interval P of the first and second cut lines  1211  and  1212 , the cutting pass B may have a process margin to some degree, and even if there are some errors along the length direction Z 2  of the double-sided adhesive film  120 , it might be prevented adhesion gap of pieces of the double-sided adhesive film  120  being detached, in which the cutting blade crosses the projections (the hatched area in  FIG. 6 ) of the first and second cut lines  1211  and  1212  and comes into contact with the first and second cut lines  1211  and  1212 . 
     More specifically, the pitch interval P of the cut line  121  may be formed to be about 20 mm to 30 mm, and the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B) may be formed to be about 10 mm to 15 mm, which is a half of the pitch interval P of the cut line  121 . In an embodiment of the present disclosure, the pitch interval P of the cut line  121  may be formed to be 25 mm, and the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B) may be formed to be 12.5 mm, which is a half of the pitch interval P of the cut line  121 . 
     As such, since the pitch interval P of the cut line  121  determines the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B), if the pitch interval P of the cut line  121  is formed to be smaller than the lower limit value (20 mm), as the cut line  121  and the cutting path B come into contact with each other, the double-sided adhesive film  120  is torn apart and detached to form an adhesion gap. In addition, when the pitch interval P of the cut line  121  is formed to be larger than the upper limit value (30 mm), that is, when the cut line  121  is sparsely formed along the length direction Z 2  of the double-sided adhesive film  120 , since the relative deformation or positional movement between the double-sided adhesive film  120  and the insulating film  110  may be allowed by the cut line  121 , and thus it becomes difficult to achieve the purpose of relieving the stress therebetween and removing the crumples or wrinkles of the insulating film  110 . 
     In an embodiment of the present disclosure, the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B) may be set in relation to the thickness of the cutting blade (not shown). For example, the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B) may be formed to be about 1 to 3 times of the thickness of the cutting blade (not shown), and preferably about 2 times of the thickness of the cutting blade (not shown). If the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B) is formed to be smaller than 1 time of the thickness of the cutting blade (not shown), as the cut line  121  and the cutting path B come into contact with each other, the double-sided adhesive film  120  may be torn apart and thus an adhesive gap may be formed. In addition, when the shortest distance D between the first and second cut lines  1211  and  1212  adjacent to each other (or the clearance width of the cutting path B) is formed to be larger than 3 times of the thickness of the cutting blade (not shown), consequently, the pitch interval P of the cut line  121  is formed widely, considering that the relative deformation or positional movement between the double-sided adhesive film  120  and the insulating film  110  may be allowed by the cut line  121 , it becomes difficult to achieve the purpose of relieving the stress therebetween and removing the crumples or wrinkles of the insulating film  110 . 
     Referring to  FIG. 6 , a plurality of cut lines  121  may be formed along the length direction Z 2  of the double-sided adhesive film  120 , and in this case, it is preferred that the plurality of cut lines  121  are arranged in parallel at a constant inclination angle θ. If the plurality of cut lines  121  are formed at different inclination angles, it may be difficult to secure a clearance width of the cutting path B through which the cutting blade passes in the process of individually cutting the continuously formed insulating adhesive tape  100  or double-sided adhesive film  120 . That is, when the first and second cut lines  1211  and  1212  adjacent to each other extend at different angles, the shortest distance D therebetween may be narrower, compared to when the first and second cut lines  1211  and  1212  adjacent to each other extend in parallel to each other. 
     In an embodiment of the present disclosure, the cut line  121  may be formed in a straight line extending obliquely along a diagonal direction inclined at a constant inclination angle θ with respect to the width direction Z 3  of the double-sided adhesive film  120 . In another embodiment of the present invention, the cut line  121  may be modified into various shapes. For example, as may be seen in the double-sided adhesive film  120 ′ shown in  FIG. 7 , the cut line  121 ′ may be formed in a V-shape or an inverted V-shape in which two straight lines extending at different angles contact each other instead of on a straight line extending obliquely in an oblique direction. However, as shown in  FIG. 6 , a cut line  121  on a straight line extending obliquely along an oblique direction may be preferred in that in the V-shape or inverted V-shape of the cut line  121 ′, it is possible to form valleys in which foreign substances W such as moisture are accumulated. 
     Although the present invention has been described with reference to the embodiments shown in the accompanying drawings, this is merely exemplary, it will be understood that those skilled in the art to which the present disclosure belongs can make various modifications and equivalent other embodiments therefrom. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure may be applied to a battery pack as an energy source capable of charging and discharging, and may also be applied to various appliances using the battery pack as a driving power source.