Battery Pack

Abstract

A battery pack is disclosed, comprising: battery cells arranged in a first direction and a bus bar assembly coupled to an upper portion of the battery cells, the bus bar assembly having a bus bar electrically connected to the battery cells, a flexible substrate configured to measure state information of the battery cells, and an insulating film surrounding the bus bar and the flexible substrate.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0164707 filed in the Korean Intellectual Property Office on November 30, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0002] An embodiment of the present disclosure relates to a battery pack. Background Art

[0003] Generally, unlike non-rechargeable primary batteries, secondary batteries can be discharged and charged. Secondary batteries are used as energy sources for, for example, mobile devices, electric vehicles, hybrid vehicles, electric bicycles, or uninterruptible power supplies (UPS). Depending on the type of external device used with the battery, a single secondary battery may be used, or a battery module or battery pack in which a plurality of batteries are bundled by electrically connecting the batteries may be used.

[0004] Small mobile devices (e.g., cellular phones) can operate for a period of time using the output and capacity of a single battery. However, when long-term operation and high-power operation are required, such as in electric vehicles or hybrid vehicles that consume a lot of power, a battery module or battery pack including a large number of batteries is preferred, so that the output voltage or output current can be increased according to the number of built-in batteries. Summary of the invention

[0005] A battery pack according to an embodiment may include battery cells arranged in a first direction and a bus bar assembly coupled to upper portions of the battery cells, the bus bar assembly having bus bars electrically connected to the battery cells, a flexible substrate configured to measure state information of the battery cells, and an insulating film surrounding the bus bars and the flexible substrate.

[0006] The insulating film may include a first insulating film located on an upper portion of the flexible substrate and the bus bar and a second insulating film located on a lower portion of the flexible substrate and the bus bar.

[0007] The bus bar may include a body and a connection portion extending to one side of the body and coupled to an electrode terminal of the battery cell, and each of the first and second insulating films includes a terminal hole exposing the connection portion.

[0008] The flexible substrate may include a temperature measuring unit for measuring a temperature of the battery cell and a sensing plate for measuring a voltage of the battery cell, and each of the first insulating film and the second insulating film may include a first hole exposing the temperature measuring unit.

[0009] The first insulating film may include a second hole exposing a portion of the sensing plate.

[0010] The battery pack may further include a third insulating film located between the first insulating film and the second insulating film.

[0011] The bus bar may include a first bus bar located between the first insulating film and the third insulating film and a second bus bar located between the third insulating film and the second insulating film.

[0012] The bus bar may include a body and a connection portion extending to one side of the body and coupled to the electrode terminal of each of the battery cells, and the second bus bar may further include a bent portion between the body and the connection portion.

[0013] The height of the bent portion may correspond to the thickness of the third insulating film.

[0014] The third insulating film may be formed to have an area smaller than those of the first insulating film and the second insulating film, and may be located between the body of the first bus bar and the body of the second bus bar.

[0015] The flexible substrate may include a sensing plate for measuring a voltage of the battery cell, and the sensing plate may include a first sensing plate electrically connected to the first bus bar and a second sensing plate electrically connected to the second bus bar.

[0016] The third insulating film may include a through hole exposing a portion of the second sensing plate.

[0017] The second sensing plate may be electrically connected to the body of the second bus bar through the through-hole.

[0018] The bent portion of the second sensing plate may be formed to have a height greater than that of the bent portion of the first sensing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

[0020] Figure 1 is an exploded perspective view of a battery pack according to an embodiment of the present disclosure;

[0021] Figure 2 yes Figure 1 A cross-sectional view of a battery cell in a battery pack;

[0022] Figure 3 yes Figure 1 An exploded perspective view of a bus bar assembly in a battery pack;

[0023] Figure 4 is a perspective view of a bus bar assembly in a battery pack according to another embodiment;

[0024] Figure 5 yes Figure 4 An exploded perspective view of a bus bar assembly;

[0025] Figure 6 Among them Figure 5 A plan view of a state where the bus bar and the flexible substrate are combined;

[0026] Figure 7 yes Figure 6 an enlarged view of portion A of ; and

[0027] Figure 8 It is along Figure 6 A cross-sectional view taken along line BB. DETAILED DESCRIPTION

[0028] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, example embodiments may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art.

[0029] In the accompanying drawings, the sizes of layers and regions are exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being "on" another layer or element, the layer or element can be directly on the other layer or element, or there can be intervening layers or intervening elements. The same reference numerals represent the same elements throughout.

[0030] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In addition, it will be understood that when element A is referred to as being "connected to" element B, element A may be directly connected to element B, or an intervening element C may exist between element A and element B such that element A and element B are indirectly connected to each other.

[0031] As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. It will also be understood that when the term "includes or includes" and / or their variations are used in this specification, it indicates the presence of the stated features, quantities, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components and / or groups thereof.

[0032] For ease of description, spatially relative terms such as "under", "below", "down", "above", "on", etc. may be used herein to describe the relationship of one element or feature to another (other) element or feature as shown in the drawings. It will be understood that the spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the elements or features in the drawings are turned over, the elements described as "under" or "beneath" other elements or features will subsequently be positioned as "on" or "above" the other elements or features. Therefore, the exemplary term "under" can include both above and below orientations.

[0033] Figure 1 is an exploded perspective view of a battery pack according to an embodiment. Figure 2 yes Figure 1 A cross-sectional view of a battery cell, Figure 3 yes Figure 1 An exploded perspective view of a bus bar assembly.

[0034] Reference Figure 1 The battery pack 10 according to an embodiment of the present disclosure may include a plurality of battery cells 100 arranged in one direction and a bus bar assembly 200. The bus bar assembly 200 may be arranged above the plurality of battery cells 100, for example, the bus bar assembly 200 may be continuously overlapped with the top of all of the plurality of battery cells 100.

[0035] Reference Figure 2 , each of the battery cells 100 may include an electrode assembly 110, a first terminal 120, a second terminal 130, a case 140, and a cap plate 150. The electrode assembly 110 may be disposed in the case, the cap plate 150 seals the case 140, and the first terminal 120 and the second terminal 130 extend from the electrode assembly 110 through the cap plate 150.

[0036] The electrode assembly 110 may be formed by stacking a stack of a first electrode plate 111, a separator 113, and a second electrode plate 112, for example, in a thin plate shape or a film shape. This type of electrode assembly 110 may be referred to as a stacked type. In some examples, the first electrode plate 111 may be used as a negative electrode, the second electrode plate may be used as a positive electrode, and vice versa.

[0037] In some examples, the first electrode plate 111 may be formed by coating a first electrode active material (e.g., graphite or carbon) on a first electrode current collector made of a metal foil (e.g., copper, copper alloy, nickel, or nickel alloy). The first electrode plate 111 may include a first electrode uncoated region 111a, which is an area where the first electrode active material is not applied. In some examples, the second electrode plate 112 may be formed by coating a second electrode active material (e.g., a transition metal oxide) on a second electrode current collector made of a metal foil (e.g., aluminum or an aluminum alloy). The second electrode plate 112 may include a second electrode uncoated region 112a, which is an area where the second electrode active material is not applied. The first electrode uncoated region 111a may protrude to one side of the electrode assembly 110, and the second electrode uncoated region 112a may protrude to the other side of the electrode assembly 110. The separator 113 may be located between the first electrode plate 111 and the second electrode plate 112 to prevent a short circuit and enable movement of lithium ions, and may include, for example, polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

[0038] The first terminal 120 may be formed of metal and may be electrically connected to the first electrode plate 111. In some examples, the first terminal 120 may include a first current collecting plate 121, a first terminal column 122, and a first terminal plate 124. The first current collecting plate 121 may be electrically connected to the first electrode uncoated region 111a protruding to one end of the electrode assembly 110. A terminal hole may be formed in an upper portion of the first current collecting plate 121, and the first terminal column 122 may be inserted into the terminal hole for riveting and / or welding. The first terminal column 122 may protrude through the cap plate 150 and extend upward by a predetermined length, and may be electrically connected to the first current collecting plate 121 under the cap plate 150. The first terminal plate 124 may be coupled to the first terminal column 122.

[0039] The second terminal 130 may be made of metal and may be electrically connected to the second electrode plate 112. In some examples, the second terminal 130 may include a second current collecting plate 131, a second terminal column 132, and a second terminal plate 134. The second current collecting plate 131 may be electrically connected to the second electrode uncoated region 112a protruding from one end of the electrode assembly 110. A terminal hole may be formed in the upper portion of the second current collecting plate 131, and the second terminal column 132 may be inserted into the terminal hole for riveting and / or welding. The second terminal column 132 may protrude through the cap plate 150 and extend upward by a predetermined length, and may be electrically connected to the second current collecting plate 131 at the lower portion of the cap plate 150. The second terminal plate 134 may be coupled to the second terminal column 132. The second terminal plate 134 may be electrically connected to the cap plate 150, and the cap plate 150 and the housing 140 may have the same polarity (e.g., positive polarity) as that of the second terminal 130.

[0040] The case 140 may be made of, for example, aluminum, an aluminum alloy, or a conductive metal such as nickel-plated steel, and have a substantially hexahedral shape with an opening formed therein, and the electrode assembly 110 may be inserted and seated in the opening. The cap plate 150 may be coupled to the opening of the case 140 to seal the case 140.

[0041] The cap plate 150 may seal the opening of the housing 140 and may be made of the same material as that of the housing 140. In some examples, the cap plate 150 may be bonded to the housing 140 by laser welding. An upper coupling member 155 may be formed between each of the first terminal column 122 and the second terminal column 132 on the cap plate 150 and the cap plate 150. In addition, the upper coupling member 155 may be in close contact with the cap plate 150. The upper coupling member 155 may insulate the first terminal column 122 and the second terminal column 132 from the cap plate 150. In some examples, the upper coupling member 155 formed on the second terminal column 132 may electrically connect the second terminal plate 134 and the cap plate 150 to each other, and therefore, the second terminal 130 may have the same polarity as that of the cap plate 150 and the housing 140. The lower insulating member 156 may be formed between each of the first and second current collecting plates 121 and 131 and the cap plate 150 , and may prevent a short circuit between the first and second current collecting plates 121 and 150 and between the second current collecting plates 131 and 150 .

[0042] Reference Figure 1 , the bus bar assembly 200 may include a bus bar 210, a flexible substrate 220, a first insulating film 230, and a second insulating film 240. The bus bar assembly 200 may be disposed on top of the plurality of battery cells 100. The bus bar 210 may electrically connect the plurality of battery cells 100.

[0043] Reference Figure 3, the bus bar 210 may connect a plurality of battery cells 100 in series and / or in parallel. The bus bar 210 may include a plurality of bus bars 210 to electrically connect a plurality of battery cells 100 to each other. The bus bar 210 may be electrically connected to the first terminal 120 and / or the second terminal 130 of the battery cell 100. In some examples, the bus bar 210 may electrically connect battery cells 100 that are not adjacent to each other. In some examples, the bus bar 210 may electrically connect the first terminal 120 of one battery cell in the battery cell 100 to the first terminal 120 or the second terminal 130 of another battery cell in the battery cell 100. The bus bar 210 may be welded to the first terminal 120 or the second terminal 130 of each of the battery cells 100. The plurality of bus bars 210 may be coated or laminated with a first insulating film 230 and a second insulating film 240. In some examples, the plurality of bus bars 210 may be located in the same plane between the first insulating film 230 and the second insulating film 240, for example, the tops of the bus bars 210 may be coplanar with each other, and the bottoms of the bus bars 210 may be coplanar with each other. In some examples, output terminals 215 for leading out the output voltage of the battery pack 10 may be formed on the bus bars 210. The output terminals 215 may be led out from the battery pack 10 in the same direction.

[0044] For example, Figure 3 As shown in , each of the bus bars 210 may include a body 212 and a connection portion 211, the connection portion 211 extending (or protruding) to one side of the body 212 and electrically connected to the first terminal 120 and / or the second terminal 130 of the battery cell 100. In some examples, the connection portion 211 may include two connection portions (e.g., consist of two connection portions). The connection portion 211 may be welded to the first terminal 120 or the second terminal 130 of the battery cell 100. In some examples, the connection portion 211 may be welded to the first terminal plate 124 or the second terminal plate 134. For example, as Figure 3 As shown in , top surfaces of the body 212 and the connection portion 211 may be coplanar with each other, and bottom surfaces of the body 212 and the connection portion 211 may be coplanar with each other to define a (eg, completely) flat bus bar 210 .

[0045] For example, Figure 3 As further shown in FIG. 1 , each body 212 may extend along the x-axis, and two connecting portions 211 may extend from opposite ends of the body 212 on the y-axis (eg, extending parallel to each other). Figure 1 and Figure 3, two rows of the main body 212 along the x-axis may be arranged to overlap the first terminal 120 of the battery cell 100, and two rows of the main body 212 along the x-axis may be arranged to overlap the second terminal 130 of the battery cell 100. For example, in each of the two rows of the main body 212, the busbars 210 may be arranged in a zigzag pattern, for example, the connection portion 211 of one of the two rows may face the connection portion 211 of the other of the two rows.

[0046] The flexible substrate 220 may be located on top of the plurality of battery cells 100. In some examples, the flexible substrate 220 may extend in a direction (eg, along an x-axis) along which the plurality of battery cells 100 are arranged, and may be formed to pass through the center of the cap plate 150. Figure 3 As shown in , the flexible substrate 220 can extend between the paired rows of bus bars 210, for example, the width of the flexible substrate 220 on the y-axis can be accommodated between the paired rows of bus bars 210. In some examples, the flexible substrate 220 can be referred to as a flexible printed circuit assembly (FPCA) or a flexible printed circuit board (FPCB). In some examples, the flexible substrate 220 can measure the state information of the battery cell 100 (e.g., the voltage and / or temperature of the battery cell 100).

[0047] The flexible substrate 220 may include a temperature measuring unit 221 (i.e., a temperature measurer) for measuring the temperature of the battery cell 100 and a sensing board 225 for measuring the voltage of the battery cell 100. In some examples, the flexible substrate 220 may include a plurality of temperature measuring units 221 and a plurality of sensing boards 225 to measure the temperature and voltage of various parts of the plurality of battery cells 100. The temperature measuring unit 221 may directly contact the battery cell 100 to measure the temperature of the battery cell 100. In some examples, the temperature measuring unit 221 may include a temperature sensor (e.g., a thermistor) and a connection board welded to the battery cell 100. For example, the temperature measuring unit 221 may sense the temperature of the battery cell 100 by measuring the resistance value of the temperature sensor (i.e., thermistor). In addition, a connector 227 may be coupled to one end of the flexible substrate 220, and the flexible substrate 220 may be connected to an external system through the connector 227.

[0048] The first insulating film 230 and the second insulating film 240 can complete the bus bar assembly 200 by laminating (e.g., surrounding or encapsulating) the bus bar 210 and the flexible substrate 220. The first insulating film 230 can be bonded from the top of the flexible substrate 220 and the bus bar 210, and the second insulating film 240 can be bonded from the bottom of the flexible substrate 220 and the bus bar 210. For example, Figure 3As shown in , the first insulating film 230 may extend continuously over the bus bar 210 and the flexible substrate 220, and the second insulating film 240 may extend continuously under the bus bar 210 and the flexible substrate 220. In some examples, after positioning the bus bar 210 and the flexible substrate 220 between the first insulating film 230 and the second insulating film 240, the first insulating film 230 and the second insulating film 240 are thermally fused to form the bus bar assembly 200, for example, so that the bus bar 210 and the flexible substrate 220 may be embedded in a fused (e.g., laminated) structure of the first insulating film 230 and the second insulating film 240.

[0049] In some examples, the first insulating film 230 and / or the second insulating film 240 may include, for example, a polyethylene terephthalate (PET) film, a polyimide (PI) film, a polyethylene naphthalate (PEN) film, or a polycarbonate (PC) film. The first insulating film 230 and / or the second insulating film 240 may be any film or sheet including an insulating material.

[0050] The first insulating film 230 and the second insulating film 240 may include terminal holes 231 and 241 formed at positions corresponding to the first terminal plate 124 and the second terminal plate 134 of the battery cell 100, respectively. Figure 3 , the edges of the first insulating film 230 and the second insulating film 240 along the x-axis may be completely fused to each other to surround the bus bar 210, so that only the terminal holes 231 and 241 may expose a portion of the bus bar 210. In addition, the terminal holes 231 and 241 may expose the connection portion 211 of the bus bar 210 that is electrically connected to the first terminal plate 124 or the second terminal plate 134. The first insulating film 230 may include a first hole 232 that exposes the temperature measuring unit 221 and a second hole 233 that exposes a portion of the sensing plate 225 for measuring voltage. The first insulating film 230 may cover the remaining portion of the sensing plate 225 except for the portion exposed by the second hole 233, thereby preventing the sensing plate 225 from being corroded and preventing a short circuit from occurring between the sensing plate 225 and an external circuit. That is, the first insulating film 230 may have the same effect as coating the surface of the sensing plate 225. In addition, the first insulating film 230 may prevent an unnecessary short circuit between the bus bar 210 and an external component.

[0051] The second insulating film 240 may include a first hole 242 exposing the temperature measurement unit 221. The first hole 232 of the first insulating film 230 and the first hole 242 of the second insulating film 240 are formed at the same position (for example, the first hole 232 and the second hole 242 may be vertically overlapped with each other). Here, the second insulating film 240 is located below the bus bar 210 and the flexible substrate 220, so it is not necessary to form a second hole exposing the sensing plate 225. The second insulating film 240 can insulate the bus bar 210 and the cap plate 150 from each other.

[0052] As described above, the bus bar assembly 200 can be completed by positioning the bus bar 210 and the flexible substrate 220 between the first insulating film 230 and the second insulating film 240 and thermally fusing the first insulating film 230 and the second insulating film 240. Therefore, in the battery pack 10 according to the embodiment, a separate holder or support member for fixing the bus bar 210 and the flexible substrate 220 is not required, thereby reducing costs. In addition, in the battery pack 10 according to the embodiment, by fixing the bus bar 210 and the flexible substrate 220 using the first insulating film 230 and the second insulating film 240 that are relatively thin compared to the holder or the support member, the volume of the battery pack 10, that is, the height (e.g., along the z-axis), can be reduced, thereby increasing the energy density (or capacity per unit volume).

[0053] Figure 4 is a perspective view of a bus bar assembly according to another embodiment of the present disclosure. Figure 5 yes Figure 4 An exploded perspective view of a bus bar assembly. Figure 6 Among them Figure 5 A plan view of a state where a bus bar and a flexible substrate are combined. Figure 7 yes Figure 6 An enlarged view of part A of FIG. Figure 8 It is along Figure 6 A cross-sectional view taken along line BB.

[0054] Reference Figures 4 to 8 , the bus bar assembly 300 may include bus bars 310A and 310B, a flexible substrate 320, a first insulating film 330, a second insulating film 340, and a third insulating film 350. In some examples, Figure 3 Compared with the bus bar assembly 200 , the bus bar assembly 300 may further include a third insulating film 350 . The third insulating film 350 may be located between the first insulating film 330 and the second insulating film 340 .

[0055] The bus bars 310A and 310B may electrically connect the plurality of battery cells 100 to each other. The bus bars 310A and 310B may include a first bus bar (or referred to as a first sub-bus bar) 310A located between the first insulating film 330 and the third insulating film 350 and a second bus bar (or referred to as a second sub-bus bar) 310B located between the second insulating film 340 and the third insulating film 350. In other words, the bus bars 310A and 310B may include a first bus bar 310A located above the third insulating film 350 and a second bus bar 310B located below the third insulating film 350.

[0056] The first bus bar 310A may be located in the same plane between the first insulating film 330 and the third insulating film 350. In some examples, the first bus bar 310A may include a body 312a and a connecting portion 311a extending to one side of the body 312a and electrically connected to the first terminal 120 and / or the second terminal 130 of the battery cell 100. The connecting portion 311a may be connected to at least two or more first terminals 120 and / or second terminals 130. Although Figure 5 The first bus bar 310A is shown to include four connection portions 311a, but the first bus bar 310A may include four or more connection portions 311a. In some examples, the body 312a of the first bus bar 310A may be stacked to overlap with the body 312b of the second bus bar 310B (e.g., vertically), but the third insulating film 350 may be located between the body 312a of the first bus bar 310A and the body 312b of the second bus bar 310B to prevent a short circuit therebetween.

[0057] The second bus bar 310B may be located between the third insulating film 350 and the second insulating film 340. In some examples, the second bus bar 310B may include a body 312b, a connection portion 311b extending to one side of the body 312b to electrically connect to the first terminal 120 and / or the second terminal 130 of the battery cell 100, and a bent portion 313b located between the body 312b and the connection portion 311b. Compared to the first bus bar 310A, the second bus bar 310B may further include a bent portion 313b, for example, the bent portion 313b may extend in the z-axis to connect the connection portion 311b to the body 312b.

[0058] The body 312b may be located between the third insulating film 350 and the second insulating film 340, and the connecting portion 311b may be, for example, along Figure 5The z-axis in is located at a relatively higher position than the main body 312b. In other words, the second bus bar 310B includes a bent portion 313b located between the main body 312b and the connecting portion 311b, so the connecting portion 311b and the main body 312b are not formed in the same plane, for example, the connecting portion 311b and the main body 312b with the bent portion 313b therebetween may have a stepped shape. Here, the connecting portion 311a of the first bus bar 310A and the connecting portion 311b of the second bus bar 310B may be formed in the same plane, for example, while the main body 312a of the first bus bar 310A and the main body 312b of the second bus bar 310B may be formed in different planes. Therefore, the bus bar assembly 300 can be stably placed on the first terminal 120 and the second terminal 130 of the battery cell 100. In addition, the height of the bent portion 313b may correspond to the thickness of the third insulating film 350 (for example, equal to the thickness of the third insulating film 350).

[0059] In some examples, an output terminal 315 for leading out an output voltage of the battery pack 10 may be formed on the second bus bar 310B. The output terminal 315 may be led out from the battery pack 10 in the same direction.

[0060] The flexible substrate 320 may be located between the first insulating film 330 and the third insulating film 350. The flexible substrate 320 may be Figure 3 The flexible substrate 220 is similarly formed. The flexible substrate 320 may include a temperature measuring unit 321 for measuring the temperature of the battery cell 100 and a sensing plate 325 for measuring the voltage of the battery cell 100.

[0061] For example, Figure 7 As shown in , the temperature measurement unit 321 may include a temperature sensor 322 (e.g., a thermistor) and a connection plate 323 welded to the battery cell 100. In some examples, the temperature sensor 322 may be attached to the flexible substrate 320 by welding, and the connection plate 323 may be laser welded to the cover plate 150 of the battery cell 100. In addition, as shown in Figure 5 As shown in FIG. 3 , a connector 327 may be coupled to one end of the flexible substrate 320 , and the flexible substrate 320 may be connected to an external system through the connector 327 .

[0062] like Figure 6 and Figure 8As shown in , the sensing plate 325 may include a first sensing plate 325a electrically connected to the first bus bar 310A and a second sensing plate 325b electrically connected to the second bus bar 310B. One end of the first sensing plate 325a may be electrically connected to the flexible substrate 320, and the other end of the first sensing plate 325a may be electrically connected to the body 312a of the first bus bar 310A. The flexible substrate 320 and the first bus bar 310A are located on the third insulating film 350, and the first sensing plate 325a may include a bending portion C1 according to (e.g., equal to) the thickness difference between the flexible substrate 320 and the first bus bar 310A.

[0063] One end of the second sensing plate 325b can be electrically connected to the flexible substrate 320, and the other end of the second sensing plate 325b can be electrically connected to the body 312b of the second bus bar 310B. The other end of the second sensing plate 325b can pass through the third insulating film 350 and can be electrically connected to the body 312b of the second bus bar 310B. Since the flexible substrate 320 is located on the upper portion of the third insulating film 350 and the body 312a of the second bus bar 310B is located on the lower portion of the third insulating film 350, the second sensing plate 325b may include a bent portion C2 according to (e.g., equal to) the height difference between the flexible substrate 320 and the second bus bar 310B. In addition, since the third insulating film 350 is located between the flexible substrate 320 and the second bus bar 310B, the bent portion C2 of the second sensing plate 325b (e.g., along the Figure 5 The height of the first sensing plate 325a along the z-axis may be greater than the height of the bent portion C1 of the first sensing plate 325a (eg, along the z-axis). Figure 5 The height of the z-axis is large.

[0064] The first insulating film 330 may cover the first bus bar 310A and the flexible substrate 320 located on the third insulating film 350. The second insulating film 340 may cover the second bus bar 310B located below the third insulating film 350. In some examples, the first insulating film 330 and the second insulating film 340 may complete the bus bar assembly 300 by laminating the bus bars 310A and 310B and the flexible substrate 320 located on the upper and lower portions of the third insulating film 350. In some examples, after positioning the bus bars 310A and 310B, the flexible substrate 320, and the third insulating film 350 between the first insulating film 330 and the second insulating film 340, the first insulating film 330 and the second insulating film 340 may be thermally fused (e.g., as previously described with reference to Figure 3 ), thereby forming the bus bar assembly 300.

[0065] The first insulating film 330 and the second insulating film 340 may be formed to have the same size (e.g., area), and the third insulating film 350 may be formed to have a size (e.g., area) smaller than that of the first insulating film 330 and the second insulating film 340 (e.g., each of the first insulating film 330 and the second insulating film 340), for example, the third insulating film 350 may have a length shorter than that of each of the first insulating film 330 and the second insulating film 340 on the respective x-axis and y-axis. The first insulating film 330 and the second insulating film 340 may include terminal holes 331 and 341 formed at positions corresponding to (e.g., overlapping) the first terminal plate 124 and the second terminal plate 134 of the battery cell 100, respectively. The first insulating film 330 may include a first hole 332 exposing the temperature measurement unit 321 and a second hole 333 exposing a portion of the sensing plate 325 for measuring voltage. The second insulating film 340 may include a first hole 342 exposing the temperature measurement unit 321.

[0066] The third insulating film 350 may be located between the first insulating film 330 and the second insulating film 340, and may insulate the first bus bar 310A and the second bus bar 310B from each other. In some examples, the third insulating film 350 may be referred to as a flame retardant barrier (FRB), a flame retardant film, or a flame retardant sheet. For example, the third insulating film 350 may include a flame retardant material. The third insulating film 350 may be formed to have a size (e.g., area) smaller than that of the first insulating film 330 and the second insulating film 340, and may cover the main bodies 312a and 312b of the bus bars 310A and 310B and may expose the connecting portions 311a and 311b. The third insulating film 350 may include a through hole 353 exposing a portion of the second sensing plate 325b. The through hole 353 may be formed at a position corresponding to the second hole 333 of the first insulating film 330.

[0067] By summarizing and reviewing, the embodiment provides a battery pack having an improved busbar bonding structure, thereby improving energy density by reducing the height of the battery pack. That is, as described above, the battery pack according to the embodiment includes a busbar assembly having a busbar laminated with an insulating film and a flexible substrate, thereby reducing the height of the battery pack to improve energy density. In addition, the stacking structure of the busbar assembly eliminates the need for a separate busbar holder or support member, thereby reducing costs.

[0068] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some cases, as will be apparent to one of ordinary skill in the art, features, characteristics, and / or elements described in conjunction with a specific embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments as of the time of filing this application, unless specifically noted otherwise. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A battery pack, comprising battery cells arranged in a first direction and a bus bar assembly coupled to upper portions of the battery cells, the bus bar assembly comprising: a plurality of bus bars electrically connected to the battery cells; a flexible substrate configured to measure status information of the battery cell; as well as an insulating film surrounding the plurality of bus bars and the flexible substrate, wherein the flexible substrate extends between pairs of rows of the plurality of bus bars and includes a temperature measurer that directly contacts the battery cell to measure a temperature of the battery cell, wherein the insulating film includes a first insulating film located on an upper portion of the flexible substrate and the plurality of bus bars and a second insulating film located on a lower portion of the flexible substrate and the plurality of bus bars, each of the first insulating film and the second insulating film being a single film including an insulating material and including a terminal hole exposing a portion of each of the plurality of bus bars and a first hole exposing the temperature measurer, and The busbar assembly is completed by positioning the plurality of busbars and the flexible substrate between the first insulating film and the second insulating film and thermally fusing the first insulating film and the second insulating film.

2. A battery pack, the battery pack comprising battery cells arranged in a first direction and a bus bar assembly coupled to an upper portion of the battery cells, the bus bar assembly comprising: a plurality of bus bars electrically connected to the battery cells; a flexible substrate configured to measure status information of the battery cell; as well as an insulating film surrounding the plurality of bus bars and the flexible substrate, wherein the flexible substrate extends between pairs of rows of the plurality of bus bars and includes a temperature measurer that directly contacts the battery cell to measure a temperature of the battery cell, wherein the insulating film includes a first insulating film located on an upper portion of the flexible substrate and the plurality of bus bars and a second insulating film located on a lower portion of the flexible substrate and the plurality of bus bars, each of the first insulating film and the second insulating film being a single film including an insulating material and including a terminal hole exposing a portion of each of the plurality of bus bars and a first hole exposing the temperature measurer, wherein the busbar assembly is completed by positioning the plurality of busbars and the flexible substrate between the first insulating film and the second insulating film and thermally fusing the first insulating film and the second insulating film, wherein each of the plurality of bus bars includes a main body extending along the first direction and two connecting portions extending from two opposite ends of the main body in the first direction in a second direction intersecting the first direction, and wherein the plurality of bus bars are arranged in a zigzag pattern in each of the two rows of the bodies.

3. The battery pack according to claim 2, wherein: The connection portion of each of the plurality of bus bars is coupled to an electrode terminal of a corresponding one of the battery cells, and The terminal hole exposes the terminal hole of the connection part.

4. The battery pack according to claim 1 or 2, wherein: The flexible substrate further comprises: The sensing board is configured to measure the voltage of the battery cell.

5. The battery pack according to claim 4, wherein: The first insulating film includes a second hole exposing a portion of the sensing plate.

6. The battery pack according to claim 4, further comprising a third insulating film located between the first insulating film and the second insulating film, in, The bus bar includes a first sub-bus bar between the first insulating film and the third insulating film and a second sub-bus bar between the third insulating film and the second insulating film, and Wherein, each of the first sub-bus bar and the second sub-bus bar includes a main body and a connecting portion extending to one side of the main body, the connecting portion is coupled to the electrode terminal of the corresponding battery cell in the battery cells, and the second sub-bus bar also includes a bent portion located between the main body and the connecting portion.

7. The battery pack according to claim 6, wherein: The height of the bent portion is equal to the thickness of the third insulating film.

8. The battery pack according to claim 6, wherein: The third insulating film has an area smaller than an area of ​​each of the first insulating film and the second insulating film, and the third insulating film is located between the body of the first sub bus bar and the body of the second sub bus bar.

9. The battery pack according to claim 6, wherein: The connection portion of the first sub-bus bar and the connection portion of the second sub-bus bar are located in the same plane.

10. The battery pack according to claim 6, wherein: The sensing plate has a first sensing plate electrically connected to the first sub bus bar and a second sensing plate electrically connected to the second sub bus bar.

11. The battery pack according to claim 10, wherein: The third insulating film includes a through hole exposing a portion of the second sensing plate.

12. The battery pack according to claim 11, wherein: The second sensing plate is electrically connected to the body of the second sub-bus bar through the through-hole.

13. The battery pack according to claim 10, wherein: The bent portion of the second sensing plate has a height greater than that of the bent portion of the first sensing plate.

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