Battery pack

Abstract

According to an exemplary embodiment of the present invention, a battery pack is provided. The battery pack includes a housing, a first battery assembly and a second battery assembly disposed on the housing, each of the first battery assembly and the second battery assembly including a plurality of pouch-type battery cells, and further includes a bus bar assembly disposed on the first battery assembly and the second battery assembly, and the bus bar assembly includes a bus bar frame covering the first battery assembly and the second battery assembly, and a plurality of inter-bus bars disposed on the bus bar frame.

Description

Technical Field

[0001] The present invention relates to a battery pack. This application claims the benefit of Korean Application No. 2023-0046196, filed on April 7, 2023, which is hereby incorporated by reference in its entirety.

Background Art

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various wireless devices such as handsets, notebook computers, and wireless vacuum cleaners. In recent years, due to improvements in energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has decreased dramatically, and as the driving range of battery electric vehicles (BEVs) has increased to a level comparable to that of fuel vehicles, the main application of secondary batteries has shifted from mobile devices to mobility.

[0003] The trend in the technological development of secondary batteries for mobility is to improve energy density and safety. Here, the energy density of a secondary battery is the value obtained by dividing the maximum electrical energy that the secondary battery can store by the mass of the secondary battery. Since a high energy density of a secondary battery is directly related to the driving efficiency and driving range of mobility, various studies have been conducted to improve the energy density of secondary batteries.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the technical idea of the present invention is to provide a battery pack with improved energy density.

Means for Solving the Problems

[0005] According to an exemplary embodiment of the present invention for solving the above problems, a battery pack is provided. The battery pack includes a housing, a first battery assembly and a second battery assembly disposed on the housing, each of the first battery assembly and the second battery assembly including a plurality of pouch-type battery cells, and further includes a busbar assembly disposed on the first battery assembly and the second battery assembly, and the busbar assembly includes a busbar frame covering the first battery assembly and the second battery assembly, and a plurality of inter-busbars disposed on the busbar frame.

[0006] Each of the plurality of pouch-type battery cells includes a pouch case, a positive electrode lead and a negative electrode lead. The pouch case includes a first side facing the housing and a second side opposite to the first side. The positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are disposed on the second side, and further, the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are connected to corresponding ones of the plurality of inter-busbars.

[0007] The positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are welded to corresponding ones of the plurality of inter-busbars.

[0008] The negative electrode lead of one of the plurality of pouch-type battery cells is in contact with the upper surface of the corresponding one of the plurality of inter-busbars.

[0009] The busbar frame includes a plurality of lead slots, and further, the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells penetrate through corresponding ones of the plurality of lead slots.

[0010] The bus bar assembly includes a fireproof sheet interposed between the first battery assembly and the second battery assembly and the bus bar frame.

[0011] The bus bar frame includes a plurality of holes, the fireproof sheet includes a plurality of cutout guides, and each of the plurality of cutout guides overlaps with a corresponding one of the plurality of holes.

[0012] According to an exemplary embodiment, a battery pack is provided. The battery pack includes a housing, first to fourth battery assemblies disposed on the housing, each of the first to fourth battery assemblies including a plurality of pouch-type battery cells, a center beam interposed between the first battery assembly and the second battery assembly and the third battery assembly and the fourth battery assembly, and a bus bar assembly disposed on the first to fourth battery assemblies, and the bus bar assembly includes a bus bar frame covering the first to fourth battery assemblies.

[0013] The bus bar frame covers the center beam.

[0014] Each of the plurality of pouch-type battery cells includes a pouch case, a positive electrode lead, and a negative electrode lead. The pouch case includes a first side facing the housing and a second side opposite to the first side. The positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are disposed on the second side.

[0015] The bus bar assembly includes a plurality of inter-bus bars disposed on the bus bar frame, and the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are connected to corresponding ones of the plurality of inter-bus bars.

[0016] Each of the positive electrode leads and the negative electrode leads of the plurality of pouch-type battery cells is welded to a corresponding one of the plurality of inter-bus bars.

[0017] The positive electrode lead and the negative electrode lead of any one of the plurality of pouch-type battery cells are separated from each of the plurality of inter-bus bars.

[0018] One of the negative electrode leads of the plurality of pouch-type battery cells is in contact with the upper surface of the plurality of bus bar frames.

Advantages of the Invention

[0019] The battery pack according to an exemplary embodiment of the present invention includes a bus bar frame that covers a plurality of battery assemblies. Thereby, the number of steps in the assembly process is reduced, and the number of components assembled during the manufacture of the secondary battery is reduced, so that the manufacturing cost of the secondary battery can be reduced and the productivity of the secondary battery can be improved.

[0020] The effects obtainable from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0021]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0022] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts that conform to the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the terms in order to explain his own invention in the best way.

[0023] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, there may be various equivalents and modifications that can replace them at the time of this application.

[0024] Also, in the description of the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

[0025] Embodiments of the present invention are provided to more fully explain the present invention to an ordinary technician. Therefore, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically shown for a clearer explanation. Thus, the sizes and ratios of the respective components do not fully reflect the actual sizes and ratios.

[0026] (First Embodiment) FIG. 1 is a perspective view for explaining a battery pack 100 according to an exemplary embodiment.

[0027] FIG. 2 is an exploded perspective view for explaining a battery pack 100 according to an exemplary embodiment.

[0028] FIG. 3 is a side view of a pouch-type battery cell 121.

[0029] Referring to FIGS. 1 to 3, the battery pack 100 may include a housing 110, a plurality of battery assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6 (hereinafter 120_1 to 120_6), a center beam 130, bus bar assemblies 140_1, 140_2, and a cross bus bar 150. The battery pack 100 is the final form of a battery system mounted on mobility or the like.

[0030] The housing 110 may provide a space for arranging a plurality of battery assemblies 120_1 to 120_6. The housing 110 may include a support plate 110P and side walls 110S.

[0031] Define two directions substantially parallel to the support plate 110P as the X direction and the Y direction, and define the direction substantially perpendicular to the support plate 110P as the Z direction. Each of the X direction, the Y direction, and the Z direction can be substantially perpendicular to each other. Unless otherwise specified, the definition of the direction is the same for the following drawings. Also, in the description of the plurality of battery assemblies 120_1 to 120_6, the X direction, the Y direction, and the Z direction are defined based on the case where the plurality of battery assemblies 120_1 to 120_6 are arranged in the battery pack 100.

[0032] The support plate 110P may include a plurality of plates joined to each other by friction stir welding. The support plate 110P may include a plurality of cooling channels that are flow paths for a cooling fluid. The support plate 110P may include a plurality of cavities, whereby the support plate 110P can be lightened. Each of the plurality of cooling channels and the plurality of cavities may extend in the X direction.

[0033] The side wall 110S may be joined to the support plate 110P. The side wall 110S may extend in the Z direction. The side wall 110S may include an internal empty space, whereby the side wall 110S can be lightened. A part of the side wall 110S may be substantially perpendicular to the Y direction, and a part of the side wall 110S may be substantially perpendicular to the X direction.

[0034] The plurality of battery assemblies 120_1 to 120_6 may be arranged on the support plate 110P of the housing 110. The support plate 110P may support the plurality of battery assemblies 120_1 to 120_6. The side wall 110S may horizontally surround the plurality of battery assemblies 120_1 to 120_6.

[0035] The plurality of battery assemblies 120_1 to 120_6 may include a plurality of pouch-type battery cells 121, a first cross beam 125a, and a second cross beam 125b. The battery assembly 120_1 may be referred to as the first battery assembly, the battery assembly 120_2 may be referred to as the second battery assembly, the battery assembly 120_3 may be referred to as the third battery assembly, the battery assembly 120_4 may be referred to as the fourth battery assembly, the battery assembly 120_5 may be referred to as the fifth battery assembly, and the battery assembly 120_6 may be referred to as the sixth battery assembly.

[0036] According to an exemplary embodiment, the plurality of pouch-type battery cells 121 may be connected in series and / or in parallel. As an example, the plurality of pouch-type battery cells 121 may be connected in series with each other. As another example, the plurality of pouch-type battery cells 121 may be connected in parallel with each other. As another example, the plurality of pouch-type battery cells 121 connected in parallel may form a plurality of banks, and the plurality of banks may be connected in series with each other.

[0037] Each of the plurality of pouch-type battery cells 121 may include an electrode assembly, an electrolytic solution, and a pouch case 121C.

[0038] The electrode assembly incorporated in the battery case includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The electrode assembly is classified into a jelly roll type and a stack type according to the form of assembly. The jelly roll type electrode assembly is obtained by winding a positive electrode, a negative electrode, and a separator interposed therebetween. The stack type electrode assembly includes a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween, which are sequentially stacked. The positive electrode of the electrode assembly may be connected to the positive electrode lead 121P. The negative electrode of the electrode assembly may be connected to the negative electrode lead 121N.

[0039] The pouch case 121C may include a storage portion 121B and a terrace 121T. The storage portion 121B may provide a space for storing the electrode assembly, and thereby may have a convex shape with respect to the terrace 121T. The terrace 121T may be a sealed portion of the pouch case 121C. The terrace 121T may surround the storage portion 121B.

[0040] Each pouch case 121C of the plurality of pouch-type battery cells 121 may include first to fourth sides 121S1, 121S2, 121S3, and 121S4. The first side 121S1 of the pouch case 121C may face the support plate 110P of the housing 110. The second side 121S2 of the pouch case 121C may be opposite to the first side 121S1 of each of the plurality of pouch-type battery cells 121. The third side 121S3 and the fourth side 121S4 of the pouch case 121C may connect the first side 121S1 and the second side 121S2 of the pouch case 121C.

[0041] According to an exemplary embodiment, each of the plurality of pouch-type battery cells 121 may be a single-direction cell. According to an exemplary embodiment, the positive electrode lead 121P and the negative electrode lead 121N of each of the plurality of pouch-type battery cells 121 may be arranged in the same direction. According to an exemplary embodiment, the positive electrode lead 121P and the negative electrode lead 121N of each of the plurality of pouch-type battery cells 121 may be arranged on the second side 121S2 of the pouch case 121C of each of the plurality of pouch-type battery cells 121. The positive electrode lead 121P and the negative electrode lead 121N may protrude from the second side 121S2 of the pouch case 121C. The positive electrode lead 121P and the negative electrode lead 121N may be separated in the Y direction. The positive electrode lead 121P may be arranged at one end in the Y direction of the second side 121S2, and the positive electrode lead 121P may be arranged at the other end in the Y direction of the second side 121S2.

[0042] According to an exemplary embodiment, each of the plurality of battery assemblies 120_1 to 120_6 may further include a plurality of separators 122 (see FIG. 6) interposed between the plurality of pouch-type battery cells 121. The plurality of separators 122 (see FIG. 6) may prevent swelling of the plurality of pouch-type battery cells 121 by horizontally supporting the plurality of pouch-type battery cells 121. According to an exemplary embodiment, the plurality of separators 122 (see FIG. 6) may be a thermal barrier. According to an exemplary embodiment, each of the plurality of separators 122 (see FIG. 6) may have a high melting temperature and a low thermal conductivity. According to an exemplary embodiment, each of the plurality of separators 122 (see FIG. 6) may include a flame retardant material such as ceramic and coated glass fibers. According to an exemplary embodiment, each of the plurality of separators 122 (see FIG. 6) may also be configured to release a fire retarding material and a fire extinguishing agent when a thermal runaway event occurs.

[0043] The first cross beam 125a of the battery assemblies 120_1, 120_6 disposed on the outer periphery may be coupled to the first support beam 116a disposed on the support plate 110P of the housing 110. The first cross beam 125a and the first support beam 116a may be fixed to the support plate 110P of the housing 110 by mechanical means such as bolts.

[0044] The second cross beam 125b of the battery assemblies 120_3, 120_5 disposed on the outer periphery may be coupled to the second support beam 116b. The second support beam 116b may be disposed on the second cross beam 125b. The second cross beam 125b and the second support beam 116b may be fixed to the support plate 110P of the housing 110 by mechanical means such as bolts.

[0045] Each of the first cross beam 125a and the second cross beam 125b of the battery assemblies 120_1 to 120_6 can be spaced apart from each other with a plurality of pouch-type battery cells 121 therebetween. The first cross beam 125a and the second cross beam 125b can horizontally cover the plurality of pouch-type battery cells 121. The first cross beam 125a and the second cross beam 125b can be fixed to the plurality of pouch-type battery cells 121 by an adhesive material or the like.

[0046] According to an exemplary embodiment, the first cross beam 125a and the second cross beam 125b can be different from each other and have complementary shapes. For example, the second cross beam 125b of the battery assembly 120_2 can be coupled to the first cross beam 125a of the battery assembly 120_3. The first cross beam 125a and the second cross beam 125b coupled to each other can constitute a cross beam assembly CBA. Each of the first cross beam 125a and the second cross beam 125b of the cross beam assembly CBA can mesh with each other.

[0047] The center beam 130 can extend between the side walls 110S perpendicular to the X direction. The center beam 130 can extend in the X direction. The center beam 130 can separate the battery assemblies 120_1, 120_2, 120_5 from the battery assemblies 120_3, 120_4, 120_6. The center beam 130 can be interposed between the battery assemblies 120_1, 120_2, 120_5 and the battery assemblies 120_3, 120_4, 120_6.

[0048] Each of the bus bar assemblies 140_1 and 140_2 can extend in the X direction. The X-direction length of each of the bus bar assemblies 140_1 and 140_2 may be greater than the Y-direction length of each of the bus bar assemblies 140_1 and 140_2. The bus bar assemblies 140_1 and 140_2 can be spaced apart from each other in the Y direction. In the Y direction, a center beam 130 can be interposed between the bus bar assemblies 140_1 and 140_2. Each of the bus bar assemblies 140_1 and 140_2 can be horizontally (e.g., in the Y direction) spaced apart from the center beam 130. Each of the bus bar assemblies 140_1 and 140_2 may not overlap with the center beam 130 in the Z direction.

[0049] Each of the bus bar assemblies 140_1 and 140_2 can cover a part of the plurality of battery assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6. Each of the bus bar assemblies 140_1 and 140_2 can be spaced apart from a part of the plurality of battery assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6.

[0050] The bus bar assembly 140_1 can be disposed on the battery assemblies 120_1, 120_2, 120_5. The bus bar assembly 140_1 can cover the battery assemblies 120_1, 120_2, 120_5. The bus bar assembly 140_1 may overlap with the battery assemblies 120_1, 120_2, 120_5 in the Z direction. The bus bar assembly 140_1 may not cover the battery assemblies 120_3, 120_4, 120_6. The bus bar assembly 140_1 can be horizontally (e.g., in the Y direction) spaced apart from the battery assemblies 120_3, 120_4, 120_6. The bus bar assembly 140_1 may not overlap with the battery assemblies 120_3, 120_4, 120_6 in the Z direction.

[0051] The bus bar assembly 140_2 can be disposed on the battery assemblies 120_3, 120_4, 120_6. The bus bar assembly 140_2 can cover the battery assemblies 120_3, 120_4, 120_6. The bus bar assembly 140_2 can overlap with the battery assemblies 120_3, 120_4, 120_6 in the Z direction. The bus bar assembly 140_2 may not cover the battery assemblies 120_1, 120_2, 120_5. The bus bar assembly 140_2 can be horizontally (e.g., in the Y direction) separated from the battery assemblies 120_1, 120_2, 120_5. The bus bar assembly 140_2 may not overlap with the battery assemblies 120_1, 120_2, 120_5 in the Z direction.

[0052] In this exemplary illustration, since two bus bar assemblies 140_1 and 140_2 separated in the Y direction cover the battery assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6 arranged in 3 columns in the X direction and 2 rows in the Y direction, such an arrangement of the bus bar assemblies 140_1, 140_2 and the battery assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6 can be said to be a 3×2 arrangement. A person of ordinary skill in the art can easily arrive at the bus bar assemblies 140_1, 140_2 arranged in M×N and a plurality of battery assemblies 120_1 to 120_6 based on what is described herein. Here, M and N are each any integer of 2 or more.

[0053] The battery pack 100 may further include electrical components. The electrical components may include any electronic elements necessary to drive the battery pack.

[0054] The electrical component may include, for example, a BMS (Battery Management System). The BMS may be configured to perform monitoring, balancing, and control of the battery pack. The monitoring of the battery pack 100 may include measuring the voltage and current of specific nodes within the plurality of battery assemblies 120_1 to 120_6, and measuring the temperature at a set position inside the battery pack 100. The battery pack 100 may include measuring instruments for measuring the above-mentioned voltage, current, and temperature.

[0055] The balancing of the battery pack 100 is an operation to reduce the deviation among the plurality of battery assemblies 120_1 to 120_6. The control of the battery pack 100 includes preventing overcharging, over-discharging, and over-current generation. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing the shortening of the respective lifetimes of the plurality of battery assemblies 120_1 to 120_6.

[0056] The electrical component may further include a cooling device, a PRA (Power Relay Assembly), a safety plug, etc. The cooling device may include a cooling fan. The cooling fan may prevent overheating of each of the plurality of battery assemblies 120_1 to 120_6 by circulating the air inside the battery pack 100. The PRA may be configured to supply or cut off the power of the high-voltage battery to an external load (e.g., the motor of a vehicle). The PRA can protect the plurality of battery assemblies 120_1 to 120_6 and the external load (e.g., the motor of a vehicle) by cutting off the power supply to the external load (e.g., the motor of a vehicle) in a situation where an abnormal voltage such as a voltage surge occurs.

[0057] The battery pack 100 may further include a lead plate coupled to the side wall 110S. The lead plate may cover elements disposed inside the battery pack 100 such as the battery assemblies 120_1 to 120_6 and electrical components. The lead plate may be fixed to the side wall 110S by mechanical means such as bolts, for example.

[0058] The battery pack 100 may further include a plurality of exhaust devices. The plurality of exhaust devices may be installed on either the lead plate or the side wall 110S. The plurality of exhaust devices may provide a path for discharging high-temperature gas inside the battery pack 100 to the outside when a thermal runaway event occurs in a part of the plurality of battery assemblies 120_1 to 120_6. Thereby, thermal propagation may be delayed and the stability of the battery pack 100 may be improved.

[0059] Here, the thermal runaway of the plurality of battery assemblies 120_1 to 120_6 is a state in which the temperature changes of the plurality of battery assemblies 120_1 to 120_6 further accelerate the temperature changes, which is an uncontrollable positive feedback. The plurality of battery assemblies 120_1 to 120_6 in the thermal runaway state show a rapid temperature rise and discharge a large amount of high-pressure gas and combustion residues.

[0060] FIG. 4 is an exploded perspective view of bus bar assemblies 140_1, 140_2 according to an exemplary embodiment.

[0061] FIG. 5 is an enlarged partial plan view of the partial POR of FIG. 1.

[0062] FIG. 6 is a cross-sectional view taken along the cutting line 5I-5I' of FIG. 5.

[0063] FIG. 7 is an enlarged partial cross-sectional view of a part of FIG. 6.

[0064] Referring to FIGS. 2 and 4 to 7, each of the busbar assemblies 140_1, 140_2 may include a busbar frame 141, a plurality of fireproof sheets 143, and a plurality of inter-busbars 145a, 145b, 145c.

[0065] Each busbar frame 141 of the busbar assemblies 140_1, 140_2 may include an insulating material. Each busbar frame 141 of the busbar assemblies 140_1, 140_2 may extend in the X direction. Each busbar frame 141 of the busbar assemblies 140_1, 140_2 may include a plurality of holes 141H and a plurality of slots 141S. Each busbar frame 141 of the busbar assemblies 140_1, 140_2 may further include a coupling hole 141C for coupling with the cross-beam assembly CBA. For example, mechanical coupling means such as long bolts may pass through the cross-beam assembly CBA through the coupling hole 141C and be coupled to the support plate 110P of the housing 110.

[0066] Each positive electrode lead 121P and each negative electrode lead 121N of the plurality of pouch-type battery cells 121 may pass through corresponding ones of the plurality of slots 141S. Thereby, each busbar frame 141 of the busbar assemblies 140_1, 140_2 may horizontally support and protect each positive electrode lead 121P and each negative electrode lead 121N of the plurality of pouch-type battery cells 121. The Y-direction length of each of the plurality of slots 141S may be longer than the Y-direction length of each of the plurality of slots 141S.

[0067] The plurality of slots 141S may constitute a first slot array AR1 and a second slot array AR2. That is, the first slot array AR1 and the second slot array AR2 may each include a plurality of slots 141S arranged along the X direction. The first slot array AR1 may be parallel to the X direction and may be at the edge of the bus bar frame 141 adjacent to the side wall 110S. The second slot array AR2 may be parallel to the X direction and may be at the edge of the bus bar frame 141 adjacent to the center beam 130.

[0068] Accordingly, one of the positive electrode leads 121P and the negative electrode leads 121N of each of the plurality of pouch-type battery cells 121 may pass through the slots 141S of the first slot array AR1, and the other one of the positive electrode leads 121P and the negative electrode leads 121N of each of the plurality of pouch-type battery cells 121 may pass through the slots 141S of the second slot array AR2. For example, when the positive electrode lead 121P of the pouch-type battery cell 121 passes through the slots 141S of the first slot array AR1, the negative electrode lead 121N of the pouch-type battery cell 121 may pass through the slots 141S of the second slot array AR2.

[0069] There may be a plurality of holes 141H between the first slot array AR1 and the second slot array AR2. The first slot array AR1 and the second slot array AR2 may be spaced apart from each other with the plurality of holes 141H therebetween. The plurality of holes 141H may provide a path for exhausting high-temperature gas when a thermal runaway event occurs within the battery pack 100. Each of the plurality of slots 141S is for allowing either one of the thin positive electrode lead 121P and the negative electrode lead 121N to pass through, while each of the plurality of holes 141H is for exhausting high-temperature gas, so the area of each of the plurality of holes 141H may be even larger than the area of each of the plurality of slots 141S.

[0070] A plurality of refractory sheets 143 may be interposed between the plurality of pouch-type battery cells 121 and the bus bar frame 141. As a non-limiting example, the plurality of refractory sheets 143 and the plurality of battery assemblies 120_1 to 120_6 may correspond one-to-one. That is, each of the plurality of refractory sheets 143 has an area (e.g., an area perpendicular to the Z direction) similar to each of the plurality of battery assemblies 120_1 to 120_6, and each of the plurality of refractory sheets 143 may cover a corresponding one of the plurality of battery assemblies 120_1 to 120_6.

[0071] Based on what is described herein, a person of ordinary skill in the art can easily arrive at embodiments in which some of the plurality of refractory sheets 143 cover two or more of the plurality of battery assemblies 121_1 to 121_6, or in which two or more refractory sheets 143 cover one of the plurality of battery assemblies 121_1 to 121_6.

[0072] The plurality of refractory sheets 143 can overlap with the plurality of holes 141H. The plurality of refractory sheets 143 may not overlap with the first slot array AR1 and the second slot array AR2. The plurality of refractory sheets 143 may be horizontally (e.g., in the Y direction) spaced apart from each of the first slot array AR1 and the second slot array AR2. The plurality of refractory sheets 143 may be interposed between the first slot array AR1 and the second slot array AR2.

[0073] According to an exemplary embodiment, the plurality of refractory sheets 143 may include a refractory material such as, for example, mica. Each of the plurality of refractory sheets 143 may include a plurality of cutting guides 143G. Each of the plurality of cutting guides 143G may overlap in the Z direction with a corresponding one of the plurality of holes 141H of the bus bar frame 141. The plurality of cutting guides 143G may be formed, for example, by non-cutting processing of the plurality of refractory sheets 143 using a knife or the like. When a thermal runaway event occurs due to the plurality of cutting guides 143G, the plurality of refractory sheets 143 at the portions where the plurality of cutting guides 143G are formed may be easily broken, whereby the high-temperature gas generated from the plurality of battery assemblies 120_1 to 120_6 may be discharged through the plurality of holes 141H.

[0074] The plurality of inter-bus bars 145a, 145b, 145c may be disposed on the bus bar frame 141. The plurality of inter-bus bars 145a, 145b, 145c may include a conductive material such as, for example, metal. As a non-limiting exemplary illustration, the inter-bus bar 145a may have a substantially "L" shape, the inter-bus bar 145b may have a substantially "I" shape, and the inter-bus bar 145c may have a substantially "C" shape.

[0075] Each of the inter-bus bars 145a may include a slot 145aS, each of the inter-bus bars 145b may include a slot 145bS, and each of the inter-bus bars 145c may include a slot 145cS. Due to the slots 145aS, 145bS, 145cS, each of the plurality of inter-bus bars 145a, 145b, 145c may include a comb shape. Each positive electrode lead 121P and negative electrode lead 121N of the plurality of pouch-type battery cells 121 that have passed through the corresponding ones of the plurality of slots 141S may pass through the corresponding ones of the slots 145aS, 145bS, 145cS.

[0076] The inter-bus bar 145a can be an external connection terminal for drawing the voltages of the plurality of battery assemblies 120_1 to 120_6. The positive potential of the plurality of battery assemblies 120_1 to 120_6 can be output to any one of the inter-bus bars 145a, and the negative potential of the plurality of battery assemblies 120_1 to 120_6 can be output to another one of the inter-bus bars 145a. Any one of the inter-bus bars 145a can be in contact with the positive electrode lead 121P, and another one of the inter-bus bars 145a can be in contact with the negative electrode lead 121N.

[0077] The inter-bus bar 145b may not overlap with the cross-beam assembly CBA in the Z direction. The inter-bus bar 145b can be horizontally separated (for example, in the X direction) from the cross-beam assembly CBA. Thereby, the inter-bus bar 145b can be in contact with the relatively adjacent positive electrode lead 121P and negative electrode lead 121N.

[0078] The inter-bus bar 145c may overlap with the cross-beam assembly CBA in the Z direction. Thereby, the distance between the positive electrode lead 121P and the negative electrode lead 121N in contact with the inter-bus bar 145b can be relatively large. Thereby, each of the inter-bus bars 145b can include a comb-shaped portion separated from each other and a bridge connecting the comb-shaped portions.

[0079] The plurality of inter-bus bars 145a, 145b, 145c can be welded to the positive electrode lead 121P and the negative electrode lead 121N. Thereby, the reliability of the electrical and mechanical connection among the plurality of inter-bus bars 145a, 145b, 145c, the positive electrode lead 121P, and the negative electrode lead 121N can be improved.

[0080] The cross bus bar 150 can be disposed on the bus bar assemblies 140_1 and 140_2. The cross bus bar 150 can overlap with the bus bar assemblies 140_1 and 140_2 in the Z direction. The cross bus bar 150 can overlap with the center beam 130 in the Z direction. The cross bus bar 150 can have a substantially line shape. The cross bus bar 150 can include a slot 150S1 that overlaps with the bus bar assembly 140_1 and a slot 150S2 that overlaps with the bus bar assembly 140_2. The slot 150S1 can be at the first end of the cross bus bar 150, and the slot 150S2 can be at the second end of the cross bus bar 150. The first end and the second end of the cross bus bar 150 can be opposite to each other in the Y direction.

[0081] The cross bus bar 150 can be connected to a part of the negative electrode leads 121N of the pouch-type battery cells 121 of the battery assembly 120_5 and a part of the positive electrode leads 121P of the pouch-type battery cells 121 of the battery assembly 120_6. The cross bus bar 150 can be in contact with a part of the negative electrode leads 121N of the pouch-type battery cells 121 of the battery assembly 120_5 and a part of the positive electrode leads 121P of the pouch-type battery cells 121 of the battery assembly 120_6. The cross bus bar 150 can be welded to a part of the negative electrode leads 121N of the pouch-type battery cells 121 of the battery assembly 120_5 and a part of the positive electrode leads 121P of the pouch-type battery cells 121 of the battery assembly 120_6. The cross bus bar 150 can provide an electrical connection between a part of the negative electrode leads 121N of the pouch-type battery cells 121 of the battery assembly 120_5 and a part of the positive electrode leads 121P of the pouch-type battery cells 121 of the battery assembly 120_6.

[0082] In the case of a conventional battery pack, since each of the battery assemblies includes one or two busbar assemblies, there is a problem that the mass of the battery pack increases and the energy density and productivity of the battery pack decrease. According to an exemplary embodiment, by providing busbar assemblies 140_1 and 140_2 that cover a plurality of battery assemblies 120_1 to 120_2, the number of parts and the number of assembly steps of the battery pack 100 can be reduced. Thereby, the energy density and productivity of the battery pack 100 can be improved.

[0083] (Second Embodiment) FIG. 8 is a perspective view for explaining a battery pack 101 according to an exemplary embodiment.

[0084] FIG. 9 is an exploded perspective view of the battery pack 101 of FIG. 8.

[0085] FIG. 10 is an exploded perspective view of the busbar assemblies 140_1' and 140_2' of FIG. 8.

[0086] FIG. 11 shows a portion corresponding to FIG. 7 in the battery pack 101 of FIG. 8.

[0087] Referring to FIGS. 8 to 11, the battery pack 101 may include a housing 110, a plurality of battery assemblies 120_1 to 120_6, a center beam 130, busbar assemblies 140_1' and 140_2', and a cross busbar 150. Since the battery pack 101, the housing 110, and the plurality of battery assemblies 120_1 to 120_6 are substantially the same as those described with reference to FIGS. 1 to 7, redundant descriptions thereof are omitted.

[0088] Each of the busbar assemblies 140_1’ and 140_2’ may include a busbar frame 141, a plurality of refractory sheets 143, and an inter-busbar 145a. Since the busbar frame 141, the plurality of refractory sheets 143, and the inter-busbar 145a are substantially the same as those described with reference to FIGS. 4 to 7, duplicate descriptions thereof are omitted.

[0089] According to an exemplary embodiment, each of the busbar assemblies 140_1’ and 140_2’ may not include the inter-busbars 145b and 145c, unlike the busbar assemblies 140_1 and 140_2 of FIG. 4.

[0090] Thereby, some of the positive electrode leads 121P and negative electrode leads 121N of the pouch-type battery cells 121 may be separated from the inter-busbar 145a. Some of the positive electrode leads 121P and negative electrode leads 121N of the pouch-type battery cells 121 may not be in contact with the inter-busbar 145a.

[0091] The positive electrode lead 121P and the negative electrode lead 121N separated from the inter-busbar 145a may be welded to each other. The lowermost one of the positive electrode lead 121P and the negative electrode lead 121N welded to each other may be in contact with the upper surface 141U of the busbar frame 141. The upper surface 141U of the busbar frame 141 may be opposite to the lower surface 141L facing the plurality of pouch-type battery cells 121. In contrast, the lowermost one of the positive electrode lead 121P and the negative electrode lead 121N welded to each other in the battery pack 100 of FIG. 2 may be welded to the inter-busbar 145b as shown in FIG. 7.

[0092] According to an exemplary embodiment, other inter-bus bars 145b and 145c (see FIG. 4), except for the inter-bus bar 145a which is an external output terminal and the cross-bus bar 150 that requires a relatively long length, may be omitted. As a result, the number of components assembled during the manufacture of the battery pack 101 is reduced, so the production cost of the battery pack 101 is reduced, and the energy density of the battery pack 101 can be improved.

[0093] (Third Embodiment) FIG. 12 is a perspective view showing a battery pack 102 according to an exemplary embodiment.

[0094] FIG. 13 is an exploded perspective view of the battery pack 102 of FIG. 12.

[0095] Referring to FIGS. 12 and 13, the battery pack 102 may include a housing 110, a plurality of battery assemblies 120_1 to 120_6, a center beam 130, a bus bar assembly 140, and a cross-bus bar 150. Since the battery pack 102, the housing 110, and the plurality of battery assemblies 120_1 to 120_6 are substantially the same as those described with reference to FIGS. 1 to 7, redundant descriptions thereof are omitted.

[0096] The bus bar assembly 140 may include a first part 140P1 that is substantially the same as the bus bar assembly 140_1 in FIG. 4, a second part 140P2 that is substantially the same as the bus bar assembly 140_2 in FIG. 4, and a third part 140P3 that connects the first part 140P1 and the second part.

[0097] According to an exemplary embodiment, the bus bar assembly 140 may cover each of the plurality of battery assemblies 120_1 to 120_6. According to an exemplary embodiment, the bus bar assembly 140 may overlap with each of the plurality of battery assemblies 120_1 to 120_6 in the Z direction. According to an exemplary embodiment, the bus bar assembly 140 may cover the center beam 130. According to an exemplary embodiment, the bus bar assembly 140 may overlap with the center beam 130 in the Z direction.

[0098] As described above, the present invention has been described in more detail through the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are only one embodiment of the present invention and do not represent all of the technical ideas of the present invention. Therefore, there may be various equivalents and modifications that can replace these at the time of this application.

Description of Reference Numerals

[0099] 100, 101, 102 Battery Pack 110 Housing 110P Support Plate 110S Side Wall 116a First Support Beam 116b Second Support Beam 120_1~6, 121_1~6 Battery Assembly 121 Pouch-Type Battery Cell 121B Storage Portion 121C Pouch Case 121N Negative Electrode Lead 121P Positive Electrode Lead 121S1 First Side 121S2 Second Side 121S3 Third Side 121S4 Fourth Side 121T Terrace 122 Separator 125a First Cross Beam 125b Second Cross Beam 130 Center Beam 140 Busbar Assembly 140P1 First Part 140P2 Second Part 140P3 Third Part 141 Busbar Frame 141C Coupling Hole 141H Hole 141L Bottom Surface 141S Slot 141U Top Surface 143 Fireproof Sheet 143G Cutting Guide 145a, 145b, 145c Inter - busbar 145aS, 145bS, 145cS Slots 150 Cross - busbar 150S1, 150S2 Slots AR1 First Slot Array AR2 Second Slot Array CBA Cross - beam Assembly

Claims

1. A housing, a first battery assembly and a second battery assembly disposed on the housing, each of the first battery assembly and the second battery assembly including a plurality of pouch-type battery cells, and a busbar assembly disposed on the first battery assembly and the second battery assembly, and the busbar assembly includes a busbar frame covering the first battery assembly and the second battery assembly, and a plurality of inter-busbars disposed on the busbar frame, a battery pack.

2. Each of the plurality of pouch-type battery cells includes a pouch case, a positive electrode lead, and a negative electrode lead, the pouch case includes a first side facing the housing and a second side opposite to the first side, the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are disposed on the second side, and the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are connected to corresponding ones of the plurality of inter-busbars. The battery pack according to claim 1.

3. The positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are welded to corresponding ones of the plurality of inter-busbars. The battery pack according to claim 2.

4. One of the negative electrode leads of the plurality of pouch-type battery cells is in contact with the upper surface of the corresponding one of the plurality of inter-busbars. The battery pack according to claim 2.

5. The busbar frame includes a plurality of lead slots, and the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells penetrate through corresponding ones of the plurality of lead slots. The battery pack according to claim 2.

6. The busbar assembly includes a refractory sheet interposed between the first battery assembly and the second battery assembly and the busbar frame. The battery pack according to claim 1.

7. The busbar frame includes a plurality of holes, the refractory sheet includes a plurality of cutout guides, and The battery pack according to claim 6, wherein each of the plurality of cutting guides overlaps with a corresponding one of the plurality of holes.

8. A housing, a first to fourth battery assembly disposed on the housing, each of the first to fourth battery assemblies including a plurality of pouch-type battery cells, a center beam interposed between the first battery assembly and the second battery assembly and the third battery assembly and the fourth battery assembly, and a bus bar assembly disposed on the first to fourth battery assemblies, and the bus bar assembly includes a bus bar frame covering the first to fourth battery assemblies.

9. The battery pack according to claim 8, wherein the bus bar frame covers the center beam.

10. Each of the plurality of pouch-type battery cells includes a pouch case, a positive electrode lead, and a negative electrode lead, the pouch case includes a first side facing the housing and a second side opposite to the first side, and the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are disposed on the second side.

11. The bus bar assembly includes a plurality of inter-bus bars disposed on the bus bar frame, and the positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are connected to corresponding ones of the plurality of inter-bus bars.

12. The positive electrode lead and the negative electrode lead of each of the plurality of pouch-type battery cells are welded to corresponding ones of the plurality of inter-bus bars.

13. The positive electrode lead and the negative electrode lead of any one of the plurality of pouch-type battery cells are separated from each of the plurality of inter-bus bars.

14. The negative electrode lead of one of the plurality of pouch-type battery cells is in contact with the upper surface of the plurality of bus bar frames.

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