Battery pack

Abstract

According to an exemplary embodiment, a battery pack is provided. The battery pack includes: a battery pack case including a bottom plate and a side wall; first to third battery cell assemblies on the base plate, each of the first to third battery cell assemblies including a plurality of battery cells arranged in a first direction; a thermal insulation pad between the first battery cell assembly and the second battery cell assembly; and a first partition wall between the second battery cell assembly and the third battery cell assembly.

Description

battery pack Technical Field

[0001] This disclosure relates to a battery pack. This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0080281, filed on June 20, 2024, the entire contents of which are incorporated herein by reference. Background Technology

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as power sources for various types of wireless devices, such as mobile phones, laptops, and cordless vacuum cleaners. Recently, the primary use of secondary batteries has shifted from mobile devices to mobility services, as increased energy density and economies of scale have led to a dramatic decrease in the manufacturing cost per unit capacity, and the driving range of battery electric vehicles (BEVs) has increased to the same level as fuel cell vehicles.

[0003] As rechargeable batteries are used in mobility applications, the demand for their stability is increasing. In the event of an accident such as a fire in a rechargeable battery used in mobility applications, the driver's life could be endangered. Therefore, research into technologies to enhance the stability of rechargeable batteries is indispensable. Summary of the Invention

[0004] Technical issues

[0005] This disclosure aims to provide a battery pack with improved safety.

[0006] Technical solution

[0007] Embodiments of this disclosure provide a battery pack. The battery pack includes: a battery pack housing, which includes a base plate and sidewalls; a first battery cell assembly to a third battery cell assembly disposed on the base plate, each of the first battery cell assembly to the third battery cell assembly including a plurality of battery cells arranged in a first direction; a heat insulation pad between the first battery cell assembly and the second battery cell assembly; and a first partition wall between the second battery cell assembly and the third battery cell assembly.

[0008] The length of the heat insulation pad in the second direction perpendicular to the first direction may differ from the length of each of the first and second battery cell assemblies in the second direction.

[0009] The length of the heat insulation pad in the second direction perpendicular to the first direction can be greater than the length of each of the first battery cell assembly and the second battery cell assembly in the second direction.

[0010] The heat insulation pad can be spaced apart from the first partition wall, and the second battery cell assembly is located between the heat insulation pad and the first partition wall.

[0011] Each of the first to third battery cell assemblies may include a frame assembly surrounding a plurality of battery cells and a flame cap attached to the frame assembly.

[0012] The frame assembly may include a U-shaped frame and a top plate welded together.

[0013] The heat insulation pad can contact the flame cap of each of the first and second battery cells.

[0014] A thermal insulation pad may include a pad housing, a heat diffusion layer in the pad housing, and a heat-absorbing material.

[0015] The heat diffusion layers can be spaced apart from each other, and the heat-absorbing material is located between the heat diffusion layers.

[0016] Each layer in the heat diffusion layer may include metal.

[0017] Heat-absorbing materials can include water and highly absorbent resins.

[0018] The battery cell in each of the first to third battery cell assemblies may include a cell housing, and the cell housing may include the same material as the pad housing.

[0019] Insulation pads can be shaped like dog bones.

[0020] Insulation pads can be dumbbell shaped.

[0021] Beneficial effects

[0022] According to embodiments of this disclosure, inter-module pads comprising a housing, a thermally conductive layer, and a superabsorbent polymer (SAP) can be provided between modules. These inter-module pads are suitable for narrow spaces where crossbeams cannot be accommodated and prevent heat transfer between modules, thereby improving the safety of the battery pack.

[0023] The effects achievable from the embodiments of this disclosure are not limited to those described above, and other effects not described herein will be clearly derived and understood by those skilled in the art from the following description. In other words, unintended effects achieved when implementing the embodiments of this disclosure are those deriveable by those skilled in the art from the embodiments of this disclosure. Attached Figure Description

[0024] Figure 1 is a plan view of the battery pack according to an embodiment.

[0025] Figure 2 is a perspective view of a battery cell assembly according to an embodiment.

[0026] Figure 3 is an exploded perspective view of a battery cell assembly according to an embodiment.

[0027] Figure 4 is a flowchart of a battery pack manufacturing method according to an embodiment.

[0028] Figure 5 is a perspective view illustrating a method for manufacturing a battery pack according to an embodiment.

[0029] Figure 6 is a plan view illustrating a method for manufacturing a battery pack according to an embodiment.

[0030] Figure 7 is a side view of the heat insulation pad according to an embodiment.

[0031] Figure 8 is a cross-sectional view of the heat insulation pad according to an embodiment.

[0032] Figure 9 is a perspective view illustrating a method for manufacturing a battery pack according to an embodiment.

[0033] Figure 10 is a plan view illustrating a method for manufacturing a battery pack according to an embodiment. Detailed Implementation

[0034] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Before describing the embodiments of this disclosure, the terms or expressions used in this specification and claims should not be construed as limited to their common understanding or as defined in common dictionaries, but should be understood based on the principle that the inventors of this application can appropriately define terms or expressions to best interpret this disclosure, according to the matching meanings and concepts corresponding to this disclosure.

[0035] Therefore, the embodiments described herein and the configurations shown in the accompanying drawings are merely embodiments of this disclosure and do not reflect all the technical ideas of this disclosure. It should be understood that various equivalents and modifications have been made to replace the described configurations as of the filing date of this application.

[0036] When it is determined that a well-known configuration or function related to the description of this disclosure would obscure the subject matter of this disclosure due to unnecessary details, the configuration or function will not be described in detail.

[0037] Because the embodiments of this disclosure are provided to more fully explain the disclosure to those skilled in the art, the shapes, dimensions, etc., of the components shown in the accompanying drawings may be exaggerated, omitted, or illustrated schematically for clarity. Therefore, it should not be construed that the dimensions or proportions of the components fully reflect their actual dimensions or proportions.

[0038] (First Implementation)

[0039] Figure 1 is a plan view of the battery pack 100 according to an embodiment.

[0040] Referring to Figure 1, the battery pack 100 may include a battery pack housing 110, a plurality of battery cell assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6, 120_7, 120_8, 120_9, 120_10, 120_11, 120_12 and 120_13 (hereinafter referred to as 120_1 to 120_13), a first partition wall 131, a second partition wall 133, a third partition wall 135, a fourth partition wall 137, a fifth partition wall 139, and heat insulation pads 140_1, 140_2, 140_3 and 140_4. The battery pack 100 may be an end product installed in an application such as a vehicle.

[0041] The housing 110 can provide space for mounting multiple battery cell assemblies 120_1 to 120_13. The battery pack housing 110 may include a base plate 111 and side walls 112, 113, 114 and 115.

[0042] Each of the base plate 111 and side walls 112, 113 can be formed by an extrusion process. Side walls 114 and 115 can also be formed by an extrusion process. Side walls 112, 113, 114 and 115 can be substantially perpendicular to the base plate 111.

[0043] According to an embodiment, the base plate 111 and the side walls 112 and 113 can be joined by friction stir welding. The base plate 111 may include a plurality of unit plates joined to each other by friction stir welding.

[0044] Here, the two directions that are substantially parallel to the upper surface of the base plate 111 are defined as the X-axis direction and the Y-axis direction, and the direction that is substantially perpendicular to the upper surface of the base plate 111 is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction can be substantially perpendicular to each other.

[0045] The base plate 111 may include multiple cooling channels. These cooling channels can provide pathways for the movement of a refrigerant, such as water. The multiple cooling channels can be formed by an extrusion process.

[0046] Multiple battery cell assemblies 120_1 to 120_13 may be located on the base plate 111 of the battery pack housing 110. The base plate 111 may support the multiple battery cell assemblies 120_1 to 120_13. Side walls 112, 113, 114 and 115 may be horizontally surrounding the multiple battery cell assemblies 120_1 to 120_13.

[0047] Battery cell assemblies 120_1, 120_2, 120_3, 120_4, and 120_5 (hereinafter, 120_1 to 120_5) can be arranged in the Y-axis direction. Battery cell assemblies 120_1 to 120_5 can be arranged sequentially in the Y-axis direction. Battery cell assembly 120_2 can be inserted between battery cell assemblies 120_1 and 120_3. Battery cell assembly 120_3 can be inserted between battery cell assemblies 120_2 and 120_4. Battery cell assembly 120_4 can be inserted between battery cell assemblies 120_3 and 120_5. Battery cell assemblies 120_1 and 120_5 can be spaced apart from each other, with battery cell assemblies 120_2, 120_3, and 120_4 located between them.

[0048] Battery cell assemblies 120_6, 120_7, 120_8, and 120_9 (hereinafter, 120_6 to 120_9) can be arranged in the X-axis direction. Battery cell assemblies 120_6 to 120_9 can be arranged sequentially in the X-axis direction. Battery cell assembly 120_7 can be inserted between battery cell assemblies 120_6 and 120_8. Battery cell assembly 120_8 can be inserted between battery cell assemblies 120_7 and 120_9. Battery cell assemblies 120_6 and 120_9 can be spaced apart from each other, with battery cell assemblies 120_7 and 120_8 located between them.

[0049] Battery cell assemblies 120_10, 120_11, 120_12, and 120_13 (hereinafter, 120_10 to 120_13) can be arranged in the X-axis direction. Battery cell assemblies 120_10 to 120_13 can be arranged sequentially in the X-axis direction. Battery cell assembly 120_11 can be inserted between battery cell assemblies 120_10 and 120_12. Battery cell assembly 120_12 can be inserted between battery cell assemblies 120_11 and 120_13. Battery cell assemblies 120_10 and 120_13 can be spaced apart from each other, with battery cell assemblies 120_11 and 120_12 located between them.

[0050] Each of the first partition wall 131, the second partition wall 133, the third partition wall 135, the fourth partition wall 137, and the fifth partition wall 139 may be located on the base plate 111. Each of the first partition wall 131, the second partition wall 133, the third partition wall 135, the fourth partition wall 137, and the fifth partition wall 139 may be integrally formed with a portion of the base plate 111 by an extrusion process, or may be welded to the base plate 111.

[0051] Each of the first partition wall 131 and the second partition wall 133 may be substantially parallel to each of the side walls 112 and 113. Each of the first partition wall 131 and the second partition wall 133 may be inserted between the side walls 112 and 113.

[0052] Each of the third partition wall 135, the fourth partition wall 137, and the fifth partition wall 139 may be substantially parallel to each of the side walls 114 and 115. Each of the third partition wall 135, the fourth partition wall 137, and the fifth partition wall 139 may be inserted between the side walls 114 and 115.

[0053] Each of the first partition wall 131 and the second partition wall 133 may extend in the X-axis direction. One of the first partition walls 131 may be inserted between battery cell assemblies 120_2 and 120_3. One of the first partition walls 131 may isolate battery cell assemblies 120_2 and 120_3 in the Y-axis direction. The other of the first partition walls 131 may be inserted between battery cell assemblies 120_3 and 120_4. The other of the first partition walls 131 may isolate battery cell assemblies 120_3 and 120_4 in the Y-axis direction. The second partition wall 133 may be inserted between battery cell assemblies 120_6 to 120_9 and battery cell assemblies 120_10 to 120_13. The second partition wall 133 may isolate battery cell assemblies 120_6 to 120_9 and battery cell assemblies 120_10 to 120_13 in the Y-axis direction.

[0054] A thermal insulation pad may not be present between battery cell assemblies 120_2 and 120_3. A thermal insulation pad may not be present between battery cell assemblies 120_3 and 120_4. A thermal insulation pad may not be present between battery cell assemblies 120_6, 120_7, 120_8, and 120_9 and battery cell assemblies 120_10, 120_11, 120_12, and 120_13. Each of thermal insulation pads 140_1, 140_2, 140_3, and 140_4 may be spaced apart from each of the first partition wall 131 and the second partition wall 133.

[0055] Each of the third partition wall 135, the fourth partition wall 137, and the fifth partition wall 139 may extend in the Y-axis direction. The third partition wall 135 may be inserted between battery cell assemblies 120_1 to 120_5 and battery cell assemblies 120_6, 120_7, 120_8, 120_9, 120_10, 120_11, 120_12, and 120_13 (hereinafter referred to as 120_6 to 120_13). The third partition wall 135 may isolate battery cell assemblies 120_1 to 120_5 and battery cell assemblies 120_6 to 120_13 in the X-axis direction.

[0056] The fourth partition wall 137 may overlap each other in the Y-axis direction. The second partition wall 133 may be located between the fourth partition walls 137. One of the fourth partition walls 137 may be inserted between battery cell assemblies 120_7 and 120_8. One of the fourth partition walls 137 may isolate battery cell assemblies 120_7 and 120_8 in the Y-axis direction. The other of the fourth partition walls 137 may be inserted between battery cell assemblies 120_11 and 120_12. The other of the fourth partition walls 137 may isolate battery cell assemblies 120_11 and 120_12 in the Y-axis direction.

[0057] The fifth partition wall 139 may overlap each other in the Y-axis direction. The second partition wall 133 may be located between the fifth partition walls 139. One of the fifth partition walls 139 may be inserted between battery cell assemblies 120_8 and 120_9. One of the fifth partition walls 139 may isolate battery cell assemblies 120_8 and 120_9 in the Y-axis direction. The other of the fifth partition walls 139 may be inserted between battery cell assemblies 120_10 and 120_11. The other of the fifth partition walls 139 may isolate battery cell assemblies 120_10 and 120_11 in the Y-axis direction.

[0058] A thermal insulation pad may not be present between battery cell assemblies 120_1 to 120_5 and battery cell assemblies 120_6 to 120_13. A thermal insulation pad may not be present between battery cell assemblies 120_7 and 120_8. A thermal insulation pad may not be present between battery cell assemblies 120_8 and 120_9. A thermal insulation pad may not be present between battery cell assemblies 120_6 to 120_9 and battery cell assemblies 120_10 to 120_13. A thermal insulation pad may not be present between battery cell assemblies 120_10 and 120_11. A thermal insulation pad may not be present between battery cell assemblies 120_11 and 120_12. Each of thermal insulation pads 140_3 and 140_4 may be spaced apart from the third partition wall 135. Each of the heat insulation pads 140_1, 140_2, 140_3 and 140_4 may be spaced apart from each of the fourth partition wall 137 and the fifth partition wall 139.

[0059] Heat insulation pads 140_1, 140_2, 140_3 and 140_4 may be located in the space between multiple battery cell assemblies 120_1 to 120_13, the width of which is insufficient to accommodate the first to fifth partition walls 131, 133, 135, 137 and 139.

[0060] A heat insulation pad 140_1 can be inserted between battery cell assemblies 120_1 and 120_2. The heat insulation pad 140_1 can isolate battery cell assemblies 120_1 and 120_2 in the Y-axis direction. The heat insulation pad 140_1 can contact each of battery cell assemblies 120_1 and 120_2. The heat insulation pad 140_1 can contact the flame cap 129 (see Figure 3) of each of battery cell assemblies 120_1 and 120_2.

[0061] A heat insulation pad 140_2 can be inserted between battery cell assemblies 120_4 and 120_5. The heat insulation pad 140_2 can isolate battery cell assemblies 120_4 and 120_5 in the Y-axis direction. The heat insulation pad 140_2 can contact each of battery cell assemblies 120_4 and 120_5. The heat insulation pad 140_2 can contact the flame cap 129 (see Figure 3) of each of battery cell assemblies 120_4 and 120_5.

[0062] A heat insulation pad 140_3 can be inserted between battery cell assemblies 120_6 and 120_7. The heat insulation pad 140_3 can isolate battery cell assemblies 120_6 and 120_7 in the X-axis direction. The heat insulation pad 140_3 can contact each of battery cell assemblies 120_6 and 120_7. The heat insulation pad 140_3 can contact the flame cap 129 (see Figure 3) of each of battery cell assemblies 120_6 and 120_7.

[0063] A heat insulation pad 140_4 can be inserted between battery cell assemblies 120_12 and 120_13. The heat insulation pad 140_4 can isolate battery cell assemblies 120_12 and 120_13 in the X-axis direction. The heat insulation pad 140_4 can contact each of battery cell assemblies 120_12 and 120_13. The heat insulation pad 140_4 can contact the flame cap 129 (see Figure 3) of each of battery cell assemblies 120_12 and 120_13.

[0064] Therefore, adjacent battery cell assemblies in battery cell assemblies 120_1 to 120_13 can be isolated by one of the first to fifth partition walls 131, 133, 135, 137 and 139 and heat insulation pads 140_1, 140_2, 140_3 and 140_4 to prevent heat propagation between adjacent battery cell assemblies in battery cell assemblies 120_1 to 120_13, thereby improving the safety of battery pack 100.

[0065] The length of the heat insulation pad 140_1 (e.g., its length in the X-axis direction) may differ from the length of each of the battery cell assemblies 120_1 and 120_2 (e.g., its length in the X-axis direction). The length of the heat insulation pad 140_1 (e.g., its length in the X-axis direction) may be greater than the length of each of the battery cell assemblies 120_1 and 120_2 (e.g., its length in the X-axis direction).

[0066] The length of the heat insulation pad 140_2 (e.g., its length in the X-axis direction) may differ from the length of each of the battery cell assemblies 120_4 and 120_5 (e.g., its length in the X-axis direction). The length of the heat insulation pad 140_2 (e.g., its length in the X-axis direction) may be greater than the length of each of the battery cell assemblies 120_4 and 120_5 (e.g., its length in the X-axis direction).

[0067] The length of the heat insulation pad 140_3 (e.g., its length in the Y-axis direction) may differ from the length of each of the battery cell assemblies 120_6 and 120_7 (e.g., its length in the Y-axis direction). The length of the heat insulation pad 140_3 (e.g., its length in the Y-axis direction) may be greater than the length of each of the battery cell assemblies 120_6 and 120_7 (e.g., its length in the Y-axis direction).

[0068] The length of the heat insulation pad 140_4 (e.g., its length in the Y-axis direction) may differ from the length of each of the battery cell assemblies 120_12 and 120_13 (e.g., its length in the Y-axis direction). The length of the heat insulation pad 140_4 (e.g., its length in the Y-axis direction) may be greater than the length of each of the battery cell assemblies 120_12 and 120_13 (e.g., its length in the Y-axis direction).

[0069] The battery pack 100 may also include a battery management system (BMS). The BMS can be configured to monitor, balance, and control the battery pack 100. Monitoring of the battery pack 100 may include measuring the voltage and current of certain nodes within multiple battery cell assemblies 120_1 to 120_13 and measuring the temperature at designated locations within the battery pack 100.

[0070] Balancing the battery pack 100 is an operation to reduce deviations among the multiple battery cell assemblies 120_1 to 120_13. Control of the battery pack 100 includes prevention of overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing shortening of the lifespan of each of the multiple battery cell assemblies 120_1 to 120_13.

[0071] The battery pack 100 may also include an exhaust device coupled to sidewalls 114 and 115. One of the sidewalls 114 and 115 may include an exhaust port connected to the exhaust device. The exhaust device may be configured to delay heat propagation by venting hot gases from the interior of the battery pack 100 to the exterior in the event of a thermal runaway event in any of the multiple battery cell assemblies 120_1 to 120_13.

[0072] Here, the thermal runaway event of multiple battery cell modules 120_1 to 120_13 is a state in which the temperature change of multiple battery cell modules 120_1 to 120_13 accelerates the temperature change (i.e., uncontrollable positive feedback). The temperature of the multiple battery cell modules 120_1 to 120_13 in the thermal runaway state rises sharply, and a large amount of high-pressure gas and combustion debris are emitted.

[0073] The battery pack 100 may also include additional electronic components, such as a cooling device, a power relay assembly (PRA), and a safety plug. The cooling device may include a cooling fan. The cooling fan circulates air within the battery pack 100 to prevent overheating of each of the multiple battery cell assemblies 120_1 to 120_13. The PRA can be configured to supply or disconnect power from the high-voltage battery to an external load (e.g., a vehicle's motor). In the event of an abnormal voltage such as a voltage surge, the PRA can disconnect power to the external load (e.g., the vehicle's motor) to protect both the multiple battery cell assemblies 120_1 to 120_13 and the external load (e.g., the vehicle's motor). The additional electronic components may be inserted between the multiple battery cell assemblies 120_1 to 120_13 and the sidewall 115. The space between the battery cell assemblies 120_1 to 120_13 and the sidewall 115 may be referred to as the electronic component mounting area.

[0074] The battery pack 100 may also include multiple inter-bus bars configured to electrically connect battery cell assemblies 120_1 to 120_13. The battery cell assemblies 120_1 to 120_13 can be connected in series via the multiple inter-bus bars. Therefore, the battery pack 100 can be configured to output a high voltage to an external load (e.g., a vehicle's motor).

[0075] Figure 2 is a perspective view of the battery cell assembly 120 according to an embodiment.

[0076] Figure 3 is an exploded perspective view of the battery cell assembly 120 according to an embodiment.

[0077] Each of the multiple battery cell assemblies 120_1 to 120_13 in Figure 1 can be substantially the same as the battery cell assembly 120 which will be described below with reference to Figures 2 and 3.

[0078] The battery cell assembly 120 may include multiple battery cells 121, a pad 122, a first integrated circuit assembly 123C, a first end plate assembly 123E, a second integrated circuit assembly 124C, a second end plate assembly 124E, a U-shaped frame 125, a top plate 126, a flat flexible cable (FFC) assembly 127, a TIM layer 128, and a frame cover 129.

[0079] Each of the plurality of battery cells 121 may be a lithium-ion battery. Each of the plurality of battery cells 121 includes an electrode assembly, an electrolyte, and a cell housing 121C. The cell housing 121C may include an aluminum laminate, a cylindrical metal can, a square metal can, or a combination thereof. The technical concept of this disclosure will now be described with reference to an example in which the cell housing 121C is an aluminum laminate. Based on the description herein, those skilled in the art will be able to readily derive embodiments in which the cell housing 121C is a cylindrical or square can.

[0080] The cell housing 121C may include an inner resin layer, a metal layer, and an outer resin layer. The inner resin layer may be thermally adhesive, thus enabling it to seal the cell housing 121C. The inner resin layer may, for example, comprise a polyolefin-based material. The metal layer may include an alloy of iron, carbon, chromium, and manganese, an alloy of iron, chromium, and nickel, or aluminum.

[0081] The electrode assembly in the cell housing 121C includes a positive electrode, a negative electrode, and a separator between the positive and negative electrodes. The electrode assembly can be a wound-core type or a stacked type. A wound-core type electrode assembly may include a structure in which the positive electrode, negative electrode, and the separator between the positive and negative electrodes are wound together. A stacked type electrode assembly may include multiple positive electrodes and multiple negative electrodes sequentially stacked, along with multiple separators between them. The positive electrode may include a positive current collector and a positive electrode active material. The negative electrode may include a negative current collector and a negative electrode active material.

[0082] Each of the plurality of battery cells 121 may include a positive lead and a negative lead. The positive and negative leads may be collectively referred to as electrode leads. That is, an electrode lead can be either a positive lead or a negative lead. The positive lead may be connected to the negative electrode tab of the electrode assembly. The negative lead may be connected to the negative electrode tab of the electrode assembly.

[0083] Multiple battery cells 121 can be arranged in one direction. Each of the multiple battery cells 121 can be a bidirectional cell. Therefore, the positive and negative leads of each of the multiple battery cells 121 can protrude in opposite directions.

[0084] In the following description, the technical concept of this disclosure will be described with reference to an example in which each of the plurality of battery cells 121 is a bidirectional cell as described above. Based on the description herein, those skilled in the art will be able to readily derive embodiments in which each of the plurality of battery cells 121 is a unidirectional cell.

[0085] Some of the multiple battery cells 121 can be connected in parallel. The number of battery cells 121 to be connected in parallel can be determined by the current to be output through the battery cell assembly 120. A group of battery cells 121 connected in parallel can be called a bank. Multiple battery cells 121 can form multiple banks, and multiple banks can be connected in series. The number of banks to be connected in series can be determined by the voltage to be output through the battery cell assembly 120.

[0086] The positive lead of battery cell 121 in the first battery cell bank can be short-circuited to busbar 123P. The positive lead of battery cell 121 in the first battery cell bank can be soldered to busbar 123P. The negative lead of battery cell 121 in the last battery cell bank can be short-circuited to busbar 123N. The negative lead of battery cell 121 in the last battery cell bank can be soldered to busbar 123N. The voltage obtained from the circuit including multiple battery cells 121 can be output to the outside through busbars 123P and 123N.

[0087] The cells between the first and last cells can be referred to as intermediate cells. The negative lead of the battery cell 121 in each intermediate cell can contact the positive lead of the battery cell 121 in the next cell. The negative lead of the battery cell 121 in each intermediate cell can be soldered to the positive lead of the battery cell 121 in the next cell. The positive lead of the battery cell 121 in each intermediate cell can contact the negative lead of the battery cell 121 in the previous cell. The positive lead of the battery cell 121 in each intermediate cell can be soldered to the negative lead of the battery cell 121 in the next cell.

[0088] According to one embodiment, pad 122 may be a polyurethane pad. According to another embodiment, each of pads 122 may include an elastic material. Pads 122 may absorb the expansion of multiple battery cells 121. One or two cartridges may be inserted between adjacent pads 122, but the embodiment is not limited thereto.

[0089] According to other embodiments, pad 122 may be a thermal barrier. According to embodiments, each of the plurality of pads 122 may have a high melting temperature and low thermal conductivity. When each of the plurality of pads 122 is a thermal barrier, each of the plurality of pads 122 may include a flame-retardant material (such as ceramic or coated glass fiber).

[0090] The first integrated circuit component 123IC can be on the first side of the battery cell assembly 120. The first integrated circuit component 123IC can be connected to a plurality of battery cells 121. The positive lead of each of the odd-numbered battery cells 121 and the negative lead of the even-numbered battery cells 121 can be on the first side.

[0091] The first integrated circuit assembly 123IC may include a first insulating frame and a first integrated circuit mounted on the first insulating frame. The first insulating frame may include insulating material. The first insulating frame may support the first integrated circuit, the first busbar 123P, the second busbar 123N, the positive leads of each battery cell 121 in the odd-numbered library, and the negative leads of each battery cell 121 in the even-numbered library.

[0092] The first integrated circuit can be mounted on a first insulating frame. The first integrated circuit can be configured to be electrically connected to the positive lead of each battery cell 121 in the odd-numbered library and the negative lead of each battery cell 121 in the even-numbered library. The first integrated circuit can be configured to sense the voltage of multiple nodes comprising multiple battery cells 121. The first integrated circuit may include multiple sensing boards soldered to the positive leads of the battery cells 121 in the odd-numbered library and the negative leads of the battery cells 121 in the even-numbered library. The first integrated circuit can be connected to the positive leads of each battery cell 121 in the odd-numbered library and the negative leads of each battery cell 121 in the even-numbered library via wires, and in this case, the multiple sensing boards can be omitted.

[0093] The first end plate assembly 123E can be connected to the U-shaped frame 125 and the top plate 126. The first end plate assembly 123E can be welded to the U-shaped frame 125 and the top plate 126. The first end plate assembly 123E can be on the first side of the battery cell assembly 120. The first end plate assembly 123E can cover the first integrated circuit assembly 123IC.

[0094] The second integrated circuit assembly 124 may be located on a second side of the battery cell assembly 120. This second side may be opposite to the first side. The second integrated circuit assembly 124 may be spaced apart from the first integrated circuit assembly 123IC, with a plurality of battery cells 121 located therebetween. The second integrated circuit assembly 124 may be connected to the plurality of battery cells 121. The negative lead of each battery cell 121 in the odd-numbered battery cell group and the positive lead of each battery cell 121 in the even-numbered battery cell group may be located on the second side.

[0095] The second integrated circuit assembly 124 may include a second insulating frame, a second integrated circuit, and a second insulating cover 124C. The second insulating frame may include insulating material. The second insulating frame may support the second integrated circuit, the negative lead of each battery cell 121 in the odd-numbered library, and the positive lead of each battery cell 121 in the even-numbered library.

[0096] The second integrated circuit can be mounted on the second insulating frame. The second integrated circuit can be configured to be electrically connected to the negative lead of each battery cell 121 in the odd-numbered bank and the positive lead of each battery cell 121 in the even-numbered bank. The second integrated circuit can be configured to sense the voltage of multiple nodes comprising the multiple battery cells 121.

[0097] The second end plate assembly 124E can be connected to the U-shaped frame 125 and the top plate 126. The second end plate assembly 124E can be welded to the U-shaped frame 125 and the top plate 126. The second end plate assembly 124E can be on the second side of the battery cell assembly 120. The second end plate assembly 124E can cover the second integrated circuit assembly 124IC.

[0098] When viewed from the front, the U-shaped frame 125 may have a U-shape. The U-shaped frame 125 may include a base plate 125B and side walls 125W. Each side wall 125W may be connected to an end of the base plate 125B. Each side wall 125W may be substantially perpendicular to the base plate 125B. A top plate 126 may be attached to the U-shaped frame 125. The top plate 126 may be fixed to the U-shaped frame 125 by welding. The top plate 126 and the U-shaped frame 125 may together form a frame assembly. Alternatively, the top plate 126 and the U-shaped frame 125 may be replaced by a single frame having a hollow quadrilateral prism shape. The single frame may have a substantially the same shape as the combination of the top plate 126 and the U-shaped frame 125.

[0099] The FFC assembly 127 can be mounted on multiple battery cells 121. The FFC assembly 127 can be inserted between the multiple battery cells 121 and the top plate 126. The FFC assembly 127 can have an approximately linear shape. The FFC assembly 127 can connect a first integrated circuit and a second integrated circuit to each other. The voltage collected by the second integrated circuit can be transferred to the first integrated circuit through the FFC assembly 127.

[0100] The TIM layer 128 can be inserted between the base plate 125B and the battery cell 121. The TIM layer 128 may include, but is not limited to, a thermosetting material. The TIM layer 128 can cure at room temperature. The TIM layer 128 can fix the base plate 125B and the battery cell 121 to each other. The TIM layer 128 can thermally bond the base plate 125B and the battery cell 121 to improve the cooling efficiency of the battery cell assembly 120.

[0101] The flame cap 129 may include refractory material. The flame cap 129 may be attached to the U-shaped frame 125 and the top plate 126. The flame cap 129 may be fixed to the U-shaped frame 125 and the top plate 126 via, for example, an adhesive. The flame cap 129 may be attached to the top plate 126 and the sidewall 125W of the U-shaped frame 125. The flame cap 129 may be spaced apart from the bottom plate 125B of the U-shaped frame 125.

[0102] (Second Implementation)

[0103] Figure 4 is a flowchart of a battery pack manufacturing method according to an embodiment.

[0104] Figure 5 is a perspective view illustrating a method for manufacturing a battery pack according to an embodiment.

[0105] Figure 6 is a plan view illustrating a method for manufacturing a battery pack according to an embodiment.

[0106] Figure 7 is a side view of the heat insulation pad 140_1' according to an embodiment.

[0107] Figure 8 is a cross-sectional view of the heat insulation pad 140_1' according to an embodiment.

[0108] Figure 9 is a perspective view illustrating a method for manufacturing a battery pack according to an embodiment.

[0109] Figure 10 is a plan view illustrating a method for manufacturing a battery pack according to an embodiment.

[0110] Referring to Figures 4 through 8, battery cell assemblies 120_1 and 120_2 and a heat insulation pad 140_1' can be provided. Battery cell assemblies 120_1 and 120_2 are essentially the same as those described above with reference to Figures 2 and 3, so their repeated description is omitted here.

[0111] The heat insulation pad 140_1' may be different from the heat insulation pad 140_1 in Figure 1. The heat insulation pad 140_1' may not yet be connected to the battery cell assemblies 120_1 and 120_2, and therefore may not be pressed by the battery cell assemblies 120_1 and 120_2, and may have a different shape than the heat insulation pad 140_1 in Figure 1.

[0112] The heat insulation pad 140_1' may include a pad housing 141, a heat diffusion layer 143, and a heat-absorbing material 145. The heat insulation pad 140_1' may be configured to deform under external pressure. When the pad housing 141 comprises multiple layers, the outermost layer may include an insulating material.

[0113] A heat diffusion layer 143 may be covered by a housing 141. The housing 141 may surround the heat diffusion layer 143. Each heat diffusion layer 143 may be inserted between the housing 141 and the heat-absorbing material 145. The heat diffusion layers 143 may be spaced apart from each other, with the heat-absorbing material 145 located between them. One layer of the heat diffusion layer 143 may mediate heat transfer between the battery cell assembly 120_1 and the heat-absorbing material 145, and another layer of the heat diffusion layer 143 may mediate heat transfer between the battery cell assembly 120_2 and the heat-absorbing material 145.

[0114] Each heat diffusion layer 143 may have high thermal conductivity. The heat diffusion layer 143 may be configured to uniformly distribute heat transferred from the outside throughout the heat-absorbing material 145. Each heat diffusion layer 143 may include metal. Each of the heat diffusion layers 143 may include, for example, copper foil, but the implementation is not limited thereto.

[0115] The heat-absorbing material 145 may have a high ignition point and a high specific heat. According to an embodiment, the heat-absorbing material 145 may comprise a fluid. As another example, the heat-absorbing material 145 may comprise a powder. Therefore, the shape of each of the plurality of cooling bags 141 can be deformed according to pressure applied from the outside.

[0116] As a non-limiting example, the heat-absorbing material 145 may include water and a highly absorbent resin. The highly absorbent resin may also be referred to as a superabsorbent polymer (SAP), superabsorbent material (SAM), absorbent gel material (AGM), etc. The highly absorbent resin forms a gel upon absorbing water, and even under applied external pressure, the gel may not release the absorbed water, or may release a small amount of water.

[0117] According to an embodiment, the heat-absorbing material 145 may further include a thickener. The thickener can increase the viscosity of the heat-absorbing material 145. According to an embodiment, the heat-absorbing material 145 may further include an insulating precursor. The insulating precursor can be configured to form a porous structure (i.e., an air-collecting structure) in the carbonized layer under combustion conditions. Therefore, when the heat-absorbing material 145, which contains an insulating precursor in addition to water and a highly absorbent resin, is exposed in a thermal runaway event, the propagation of the thermal runaway event can be prevented or mitigated due to the insulating effect of the carbonized layer including the porous structure.

[0118] To distinguish between the cell housing 121C and the pad housing 141, the cell housing 121C is sometimes referred to as the first pouch housing, and the pad housing 141 as the second pouch housing. According to embodiments, the cell housing 121C and the pad housing 141 may comprise the same material, but are not limited thereto. The cell housing 121C and the pad housing 141 may also comprise different materials.

[0119] The housing 141 may cover a heat diffusion layer 143 and a heat-absorbing material 145. The heat diffusion layer 143 and the heat-absorbing material 145 may be located within the housing 141. Before being connected to the battery cell assemblies 120_1 and 120_2, the housing 141 may include a filled portion 141F, a sealed portion 141S, and an unfilled portion 141UF. The heat-absorbing material 145 may be present in the filled portion 141F of the housing 141. The sealed portion 141S of the housing 141 may be a heat-fused portion. The unfilled portion 141UF of the housing 141 may be inserted between the filled portion 141F and the sealed portion 141S. The unfilled portion 141UF of the housing 141 may be a portion without heat-absorbing material 145. The unfilled portion 141UF of the housing 141 may be an unsealed portion. The unfilled portion 141UF can be formed by removing air from the interior of the insulation pad 140 before sealing the insulation pad 140. The heat-absorbing material 145 in the filled portion 141F of the pad housing 141 can be moved to the unfilled portion 141UF of the pad housing 141 by external pressure.

[0120] When connected to battery cell assemblies 120_1 and 120_2, the filling portion 141F of the pad housing 141 can be between battery cell assemblies 120_1 and 120_2. In the pad housing 141, the filling portion 141F can overlap with battery cell assemblies 120_1 and 120_2 in the Y-axis direction.

[0121] According to one embodiment, the width of the filling portion 141F can be greater than the width of the sealing portion 141S. According to one embodiment, the width of the filling portion 141F can be greater than the width of the unfilled portion 141UF. According to one embodiment, the width of the unfilled portion 141F can be greater than the width of the sealing portion 141S.

[0122] Next, referring to Figures 4, 6, 9, and 10, in P120, battery cell assemblies 120_1 and 120_2 and heat insulation pad 140_1' can be combined with each other. Battery cell assemblies 120_1 and 120_2 and heat insulation pad 140_1' can be fixed together by adhesive. During the combination of battery cell assemblies 120_1 and 120_2 with heat insulation pad 140_1', the shape of heat insulation pad 140_1' can be changed to provide heat insulation pad 140_1.

[0123] The heat insulation pad 140_1 may include an intermediate portion 140I and a first end portion 140E1 and a second end portion 140E2 of battery cell assemblies 120_1 and 120_2. The intermediate portion 140I may be located between the first end portion 140E1 and the second end portion 140E2.

[0124] When the heat insulation pad 140_1' is pressed by the battery cell assemblies 120_1 and 120_2, the heat-absorbing material 145 can move to the first end 140E1 and the second end 140E2. According to one embodiment, the width of each of the first end 140E1 and the second end 140E2 may be different from the width of the intermediate portion 140I. According to another embodiment, the width of each of the first end 140E1 and the second end 140E2 may be greater than the width of the intermediate portion 140I.

[0125] According to one embodiment, the shape of the upper surface of the heat insulation pad 140_1 may include a dog bone shape. According to another embodiment, the shape of the upper surface of the heat insulation pad 140_1 may include a dumbbell shape.

[0126] The battery cell assemblies 120_1 and 120_2 and the heat insulation pad 140_1 can then be loaded into the battery pack housing 100 (see FIG. 1). The battery cell assemblies 120_4 and 120_5 and the heat insulation pad 140_2, the battery cell assemblies 120_6 and 120_7 and the heat insulation pad 140_3, and the battery cell assemblies 120_12 and 120_13 and the heat insulation pad 140_4 can be provided by a method substantially the same as that described above with reference to FIGS. 4 to 10, and therefore their repeated description is omitted here.

[0127] The present disclosure has been described in more detail above with reference to the accompanying drawings and embodiments. However, the configurations shown in the drawings or the embodiments described in this specification are merely examples of the present disclosure and do not reflect all the technical ideas of the present disclosure. Therefore, it should be understood that various equivalents and modifications have been made to replace the configurations as of the date of filing of this application.

Claims

1. A battery pack, the battery pack comprising: A battery pack housing, the battery pack housing including a base plate and side walls; a first battery cell assembly to a third battery cell assembly disposed on the base plate, each of the first battery cell assembly to the third battery cell assembly including a plurality of battery cells arranged in a first direction; a heat insulation pad between the first battery cell assembly and the second battery cell assembly; and a first partition wall between the second battery cell assembly and the third battery cell assembly.

2. The battery pack according to claim 1, wherein, The length of the heat insulation pad in the second direction perpendicular to the first direction is different from the length of each of the first battery cell assembly and the second battery cell assembly in the second direction.

3. The battery pack according to claim 1, wherein, The length of the heat insulation pad in the second direction perpendicular to the first direction is greater than the length of each of the first battery cell assembly and the second battery cell assembly in the second direction.

4. The battery pack according to claim 1, wherein, The heat insulation pad is spaced apart from the first partition wall, and the second battery cell assembly is located between the heat insulation pad and the first partition wall.

5. The battery pack according to claim 1, wherein, Each of the first to the third battery cell assemblies includes a frame assembly surrounding the plurality of battery cells and a flame cap connected to the frame assembly.

6. The battery pack according to claim 5, wherein, The frame assembly includes a U-shaped frame and a top plate welded together.

7. The battery pack according to claim 5, wherein, The heat insulation pad contacts the flame cap of each of the first battery cell and the second battery cell.

8. The battery pack according to claim 1, wherein, The heat insulation pad includes a pad shell, a heat diffusion layer in the pad shell, and a heat-absorbing material.

9. The battery pack according to claim 8, wherein, The heat diffusion layers are spaced apart from each other, and the heat-absorbing material is located between the heat diffusion layers.

10. The battery pack according to claim 8, wherein, Each layer of the heat diffusion layer comprises a metal.

11. The battery pack according to claim 8, wherein, The heat-absorbing material comprises water and a highly absorbent resin.

12. The battery pack according to claim 8, wherein, The battery cell of each of the first to the third battery cell assemblies includes a cell housing, wherein the cell housing comprises the same material as the pad housing.

13. The battery pack according to claim 1, wherein, The heat insulation pad has a dog bone shape.

14. The battery pack according to claim 1, wherein, The heat insulation pad has a dumbbell shape.

Images