Battery pack

Abstract

According to an exemplary embodiment, a battery pack is provided, the battery pack including: a pack housing including a base plate and a sidewall, a plurality of battery cell assemblies disposed on the base plate, a plurality of first TIM (Thermal Interface Material) layers interposed between the plurality of battery cell assemblies and the pack housing, a lid coupled to the sidewall, and a second TIM layer interposed between the lid and the plurality of battery cell assemblies, each of the plurality of battery cell assemblies including a plurality of battery cells arranged along a first direction and a plurality of L-shaped cooling fins interposed between the plurality of battery cells.

Description

Technical Field

[0001] The present invention relates to a battery pack. This application claims the benefit of Korean Application No. 10-2024-0005409, filed on Jan. 12, 2024, 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 cordless devices such as handsets, notebook computers, and cordless 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 been significantly reduced, and as the driving range of battery electric vehicles (BEVs) increases to a level comparable to that of fuel vehicles, the main application of secondary batteries has shifted from mobile devices to mobility.

[0003] In the current trend where secondary batteries for mobility are emphasized, the main directions of secondary battery technology development are cost reduction in production and improvement in safety. Secondary batteries account for the largest proportion of the manufacturing cost of BEVs. Therefore, the most important factor for the increase in the share of BEVs over internal combustion engine vehicles is the production cost of secondary batteries. Cost reduction in production can be achieved by reducing raw materials, reducing the number of steps in the production process, and reducing tact time. The safety of secondary batteries is very important because it is directly related to the lives of mobility passengers. The main challenge for improving the safety of secondary batteries is to provide a cooling solution for the battery pack.

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 cooling efficiency.

Means for Solving the Problems

[0005] According to an exemplary embodiment of the present invention for solving the above-mentioned problems, a battery pack is provided. The battery pack includes a pack housing including a base plate and a side wall; a plurality of battery cell assemblies disposed on the base plate; a plurality of first TIM (Thermal Interface Material) layers interposed between the plurality of battery cell assemblies and the pack housing; a lid bonded to the side wall; and a second TIM layer interposed between the lid and the plurality of battery cell assemblies, each of the plurality of battery cell assemblies including a plurality of battery cells arranged along a first direction and a plurality of L-shaped cooling fins interposed between the plurality of battery cells.

[0006] Each of the above-mentioned cooling fins includes a first portion perpendicular to the first direction and a second portion connected to the first portion and parallel to the first direction.

[0007] The length of the second portion of each of the multiple cooling fins in the first direction is different from the length of the multiple battery cells in the first direction.

[0008] The length of the second portion of each of the multiple cooling fins in the first direction is shorter than the length of the multiple battery cells in the first direction.

[0009] The length of the second portion of each of the multiple cooling fins in the first direction is longer than the length of the multiple battery cells in the first direction.

[0010] The length of the second portion of each of the multiple cooling fins in the first direction is shorter than twice the length of the multiple battery cells in the first direction.

[0011] The second TIM layer is in contact with the second portion of the multiple cooling fins of the multiple battery cell assemblies and with the lid.

[0012] The second portion of the above-mentioned multiple cooling fins is separated from the lid with the second TIM layer in between.

[0013] Each of the above-mentioned battery cells includes a terrace which is a sealed portion, and the above-mentioned cooling fins cover the terrace of the corresponding battery cell.

[0014] Each of the terraces of the above-mentioned multiple battery cells is separated from the second TIM layer.

[0015] Each of the above cooling fins may be made of aluminum or stainless steel.

[0016] Each of the above cooling fins is attached to the corresponding battery cell using an adhesive.

[0017] The shape of each of the cooling fins described above is different from a C shape.

[0018] Each of the above-mentioned cooling fins is separated from the base plate.

[0019] Each of the above-mentioned cooling fins is separated from the first TIM layer. [Effects of the Invention]

[0020] According to an exemplary embodiment of the present invention, the formation of an air layer between the TIM layer and the battery cell can be prevented by the multiple cooling fins, thereby improving the cooling efficiency of the battery pack.

[0021] The effects obtained 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 with ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following explanations. That is, unintentional effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those with ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0022] [Figure 1] It is a plan view for explaining a battery pack according to an exemplary embodiment. [Figure 2] It is an exploded perspective view of a battery pack according to an exemplary embodiment. [Figure 3] It is a perspective view of a battery cell assembly according to an exemplary embodiment. [Figure 4] It is a cross-sectional view taken along the cutting line 3I - 3I' of FIG. 3. [Figure 5] It is a partial enlarged cross-sectional view of a part of FIG. 4. [Figure 6] It is a cross-sectional view for explaining a battery cell assembly according to another exemplary embodiment. [Figure 7] It is a flowchart for explaining a method of assembling a battery pack according to another exemplary embodiment. [Figure 8] It is a perspective view for explaining a method of assembling a battery pack according to another exemplary embodiment. [Figure 9] It shows a battery cell assembly according to another exemplary embodiment. [Figure 10] It is a cross-sectional view taken along the cutting line 9I - 9I' of FIG. 9. [Figure 11] It is a partial enlarged cross-sectional view of a part of FIG. 10.

Modes for Carrying Out the Invention

[0023] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. As a premise, terms and words used herein and in the claims should not be interpreted in a manner limited to their usual or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their own invention.

[0024] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention; there may be a variety of equivalents and modifications that can substitute for them at the time of filing.

[0025] Furthermore, in describing 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, such detailed description will be omitted.

[0026] Since embodiments of the present invention are provided to give a more complete explanation to an ordinary person, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes and proportions.

[0027] (First Embodiment) Figure 1 is a perspective view illustrating a battery pack 100 according to an exemplary embodiment.

[0028] Figure 2 is an exploded perspective view of a battery pack 100 according to an exemplary embodiment.

[0029] Figure 3 is a perspective view of a battery cell assembly 120 according to an exemplary embodiment.

[0030] Figure 4 is a cross-sectional view along the cutting line 3I-3I' in Figure 3.

[0031] Figure 5 is an enlarged partial cross-sectional view of the POR portion of Figure 4.

[0032] Referring to Figures 1 to 5, the battery pack 100 may include a pack housing 110, multiple battery cell assemblies 120, a first TIM (Thermal Interface Material) layer 131, a second TIM layer 133, a gasket 140, a lid 150, a lower injection pipe 161, an upper injection pipe 163, a lower recovery pipe 171, and an upper recovery pipe 173. The battery pack 100 is the final form of a battery system installed in a mobility vehicle or the like.

[0033] The pack housing 110 can provide space for arranging multiple battery cell assemblies 120. The pack housing 110 may include a base plate 111, side walls 112, 113, 114, 115, and a center beam 116.

[0034] The two directions substantially parallel to the mounting surface of the base plate 111 are defined as the X and Y directions, and the direction substantially perpendicular to the mounting surface of the base plate 111 is defined as the Z direction. The X, Y, and Z directions may each be substantially perpendicular to one another. Unless otherwise stated, the definitions of directions are the same for the following drawings.

[0035] The base plate 111 and the side walls 112, 113 can each be provided by an extrusion process. The extrusion direction of the base plate 111 and the side walls 112, 113 can be the X direction. The base plate 111 and the side walls 112, 113 can be arranged in the Y direction. The side walls 114, 115 can also be provided by an extrusion process.

[0036] According to an exemplary embodiment, the base plate 111 and the side walls 112, 113 can be joined by friction stir welding. The base plate 111 may include a plurality of unit plates joined by friction stir welding.

[0037] The pack housing 110 may include a center beam 116. The center beam 116 may extend in the X direction. The center beam 116 may be interposed between the side walls 112 and 113. The center beam 116 may be included in a center plate positioned at the center of a plurality of unit plates that are friction stir welded to each other. This allows the center beam 116 to be formed together with the center plate in the extrusion process, and the center beam 116 may be a continuous element integrated with the center plate.

[0038] The base plate 111 may include multiple cooling channels. These multiple cooling channels can provide passages for the movement of a coolant, such as water. The multiple cooling channels can be formed by an extrusion process. The multiple cooling channels may extend in the X direction. The multiple cooling channels may be spaced apart in the Y direction.

[0039] The cooling channels of the base plate 111 can be connected to the lower injection pipe 161 and the lower recovery pipe 171. Cooling fluid introduced from the lower injection pipe 161 can flow through the cooling channels and be recovered by the lower recovery pipe 171.

[0040] Multiple battery cell assemblies 120 can be arranged on a base plate 111 of the pack housing 110. The base plate 111 can support the multiple battery cell assemblies 120. Side walls 112, 113, 114, and 115 can horizontally surround the multiple battery cell assemblies 120.

[0041] A first TIM layer 131 can be interposed between the multiple battery cell assemblies 120 and the base plate 111. The first TIM layer 131 may contain a resin composition. The first TIM layer 131 can be provided by a thermal resin coating process. The first TIM layer 131 can prevent the formation of an air layer between the base plate 111 and the battery cells 121, thereby promoting the cooling of the multiple battery cell assemblies 120. The first TIM layer 131 can be in contact with the multiple battery cells 121 of the multiple battery cell assemblies 120 and the base plate 111.

[0042] The resin composition may be a room-temperature curing composition; that is, the curing reaction of the resin composition can begin and proceed at room temperature. The curing reaction of the resin composition can be accelerated at temperatures higher than room temperature. The curing reaction rate of the resin composition at temperatures higher than room temperature may be faster than the curing reaction rate of the resin composition at room temperature. As a non-limiting example, the main component of the resin composition may be any one of silicone resin, polyol resin, epoxy resin, and acrylic resin.

[0043] Each of the multiple battery cell assemblies 120 may include multiple battery cells 121, multiple pads 122, a first circuit assembly 123, a second circuit assembly 124, a first crossbeam 125a, a second crossbeam 125b, and multiple cooling fins 126.

[0044] Each of the multiple battery cells 121 may be a lithium-ion battery. Each of the multiple battery cells 121 includes an electrode assembly, an electrolyte, and a case. Each of the multiple battery cells 121 may be one of a cylindrical battery cell, a prismatic battery cell, or a pouch-type battery cell. The case for a cylindrical battery cell may be a cylindrical metal can. The electrode assembly of a cylindrical battery cell is housed in a cylindrical metal can. The case for a prismatic battery cell may be a prismatic metal case. The electrode assembly of a prismatic battery cell is housed in a prismatic metal can. The case for a pouch-type battery cell may be a pouch sheet. The electrode assembly of a pouch-type battery cell is housed in a pouch case containing an aluminum laminate sheet.

[0045] An electrode assembly may include a positive electrode, a negative electrode, and a separation membrane interposed between the positive and negative electrodes. The electrode assembly may be either a jelly roll type or a stack type. A jelly roll type electrode assembly may include a winding structure of the positive electrode, negative electrode, and separation membrane interposed between them. A stack type electrode assembly may include multiple sequentially stacked positive electrodes, multiple negative electrodes, and multiple separation membranes interposed between them.

[0046] Multiple battery cells 121 can constitute multiple banks. Each of these banks can contain one or more battery cells 121. One or more battery cells 121 in each of these banks can be connected in parallel. Multiple banks can be connected in series. The number of banks connected in series and the number of battery cells 121 included in each bank can be determined according to the magnitude of the voltage and current that each of the battery cell assemblies 120 is to output.

[0047] Multiple pads 122 can be interposed between multiple battery cells 121. Multiple pads 122 can horizontally pressurize the multiple battery cells 121 and absorb changes in width in the X direction due to swelling of the multiple battery cells 121. Multiple pads 122 can isolate the multiple battery cells 121 from each other. According to an exemplary embodiment, each of the multiple battery cells 121 may be made of PU (Polyurethane). According to an exemplary embodiment, each of the multiple battery cells 121 may be made of a fire-resistant material such as silicone.

[0048] According to an exemplary embodiment, each of the plurality of pads 122 can be arranged alternately with two banks. According to an exemplary embodiment, two of the plurality of banks can be interposed between adjacent pads 122. According to another exemplary embodiment, only one bank may be interposed between adjacent pads 122, or three or more banks may be interposed.

[0049] The first integrated circuit assembly 123 and the second integrated circuit assembly 124 can be spaced apart in the Y direction with multiple battery cells 121 in between. The first integrated circuit assembly 123 may include an insulating frame, an integrated circuit, busbars, and an insulating cover. The second integrated circuit assembly 124 may also include an insulating frame, an integrated circuit, and an insulating cover. The second integrated circuit assembly 124 is largely similar to the first integrated circuit assembly 123, except that it does not include busbars.

[0050] The insulating frame may include an insulating material such as plastic. The insulating frame can cover the front of multiple battery cells 121. The insulating frame can support integrated circuits, busbars, and sensing plates.

[0051] The busbar can be short-circuited to the positive leads of one or more battery cells 121 in the first bank and the negative leads of one or more battery cells 121 in the last bank. The busbar can be welded to the positive leads of one or more battery cells 121 in the first bank and the negative leads of one or more battery cells 121 in the last bank. The resulting voltages of multiple battery cells 121 can be output through the busbar. The busbar can be fixed to an insulating frame.

[0052] The integrated circuit can be mounted on an insulating frame. Positive and negative leads, welded to each other, can constitute nodes within the battery cell assembly 120. The integrated circuit can be configured to measure the voltage at the nodes.

[0053] The insulating cover may contain an insulating material such as plastic. The insulating cover can be mated and coupled to an insulating frame. The insulating cover can cover an integrated circuit, thereby protecting the electrical elements of the first integrated circuit assembly 123.

[0054] Each of the first crossbeams 125a and second crossbeams 125b of the battery cell assembly 120 can be spaced apart from each other with multiple battery cells 121 in between. The first crossbeam 125a and second crossbeam 125b can cover multiple battery cells 121. The first crossbeam 125a and second crossbeam 125b can horizontally support multiple battery cells 121. The first crossbeam 125a and second crossbeam 125b can be fixed to the multiple battery cells 121 by an adhesive or the like.

[0055] According to exemplary embodiments, the first crossbeam 125a and the second crossbeam 125b may have different and complementary shapes. For example, each second crossbeam 125b of a battery cell assembly 120 may be coupled to the first crossbeam 125a of a subsequent battery cell assembly 120. For example, the second crossbeam 125b of a battery cell assembly 120 may be coupled to the first crossbeam 125a of a battery cell assembly 120.

[0056] The first crossbeam 125a and the second crossbeam 125b, joined together, can constitute a crossbeam assembly. Each of the first crossbeam 125a and second crossbeam 125b in the crossbeam assembly can engage with each other. Each of the first crossbeam 125a and second crossbeam 125b in the crossbeam assembly can touch each other. Each of the crossbeam assemblies can be extended in the Y direction.

[0057] The first crossbeam 125a of the battery cell assembly 120 adjacent to the side wall 114 can be coupled to a supporting beam located on the base plate 111. The second crossbeam 125b of the battery cell assembly 120 adjacent to the side wall 115 can be coupled to a supporting beam located on the second crossbeam 125b. Similarly, the first crossbeam 125a of the battery cell assembly 120 adjacent to the side wall 115 can be coupled to a supporting beam located on the base plate 111. The second crossbeam 125b of the battery cell assembly 120 adjacent to the side wall 115 can be coupled to a supporting beam located on the second crossbeam 125b.

[0058] Each of the multiple cooling fins 126 can have high thermal conductivity. Each of the multiple cooling fins 126 can include a metallic material such as aluminum and stainless steel.

[0059] Each of the multiple cooling fins 126 may have an L-shape. The shape of each of the multiple cooling fins 126 may differ from a C-shape. Each of the multiple cooling fins 126 may include a first portion 126V substantially perpendicular to the X direction and a second portion 126H substantially parallel to the X direction. The second portion 126H may be connected to the first portion 126V. The first portion 126V of each of the multiple cooling fins 126 may be substantially parallel to the Z direction. The second portion 126H of each of the multiple cooling fins 126 may be substantially perpendicular to the Z direction.

[0060] The second portion 126H and the first portion 126V can be extended in the Y direction. The second portion 126H of each of the multiple cooling fins 126 can guide the hot gas and flames emitted from the multiple battery cells 121 in the Y direction during a thermal runaway event. This prevents a thermal runaway event occurring in one of the multiple battery cells 121 from propagating to the others, thereby improving the safety of the battery pack 100.

[0061] Each of the multiple cooling fins 126 can be separated from the first TIM layer 131 interposed between the multiple battery cells 121 and the base plate 111. Each of the multiple cooling fins 126 can be separated from the base plate 111. Each of the multiple cooling fins 126 does not have to include a portion interposed between the multiple battery cells 121 and the base plate 111.

[0062] The length in the X direction of each second portion 126H of the multiple cooling fins 126 may differ from the length in the X direction of each of the multiple battery cells 121. The length in the X direction of each second portion 126H of the multiple cooling fins 126 may be shorter than the length in the X direction of each of the multiple battery cells 121. This prevents interference between the multiple cooling fins 126 when the multiple battery cells 121 are coupled together.

[0063] The length in the Z direction of each first portion 126V of the multiple cooling fins 126 may differ from the length in the Z direction of each of the multiple battery cells 121. The length in the Z direction of each first portion 126V of the multiple cooling fins 126 may be longer than, but not limited to, the length in the Z direction of each of the multiple battery cells 121. The length in the Z direction of each first portion 126V of the multiple cooling fins 126 may be the same as, or shorter than, the length in the Z direction of each of the multiple battery cells 121.

[0064] Multiple cooling fins 126 can be interposed between multiple battery cells 121. Each first portion 126V of the multiple cooling fins 126 can be interposed between multiple battery cells 121. Each of the multiple cooling fins 126 can be coupled to a corresponding battery cell 121. According to an exemplary embodiment, multiple battery cells 121 and multiple cooling fins 126 can correspond one-to-one.

[0065] According to an exemplary embodiment, one of a plurality of cooling fins 126 can be interposed between two adjacent battery cells 121. According to an exemplary embodiment, one of a plurality of battery cells 121 can be interposed between two adjacent cooling fins 126.

[0066] Multiple cooling fins 126 can be coupled to multiple battery cells 121. Multiple cooling fins 126 can be coupled to multiple battery cells 121, for example, by adhesive. Adhesive can be applied between each first portion 126V of the multiple cooling fins 126 and the multiple battery cells 121.

[0067] Each second portion 126H of the multiple cooling fins 126 can be separated from the multiple battery cells 121. Each second portion 126H of the multiple cooling fins 126 can cover the terrace 121T of the corresponding battery cell 121. The terraces 121T of the multiple battery cells 121 can be separated from the second TIM layer 133. Each terrace 121T of the multiple battery cells 121 can be isolated from the second TIM layer 133 by the multiple cooling fins 126. Here, the terrace 121T may be the sealed portion of the pouch case of each of the multiple battery cells 121. The terrace 121T can be secured to the storage portion of the pouch case by folding tape.

[0068] The center beam 116 can be extended in the X direction. The center beam 116 can overlap with the center of the base plate. The center beam 116 can isolate the battery cell assemblies 120 from each other. The center beam 116 can be interposed between the battery cell assemblies 120.

[0069] In this example, the multiple battery cell assemblies 120 are arranged in two rows and three columns. Thus, the multiple battery cell assemblies 120 are arranged in a 3x2 configuration. A typical technician in the industry can easily arrive at a battery pack containing multiple battery cell assemblies 120 arranged in an MxN configuration based on what is described here, where M and N are any integers greater than or equal to 2.

[0070] The lid 150 can be coupled to the side walls 112, 113, 114, and 115. The lid 150 can be fixed to the side walls 112, 113, 114, and 115 by mechanical means such as bolts. The lid 150 can cover elements located inside the battery pack 100, such as the battery cell assembly 120 and electrical components. A gasket 140 can be interposed between the lid 150 and the side walls 112, 113, 114, and 115. The gasket can provide liquid tightness to the battery pack 100.

[0071] According to an exemplary embodiment, the lid 150 can be provided by an extrusion process. The lid 150 may include a plurality of cooling channels. The plurality of cooling channels can provide passages for the movement of a coolant, such as water. The plurality of cooling channels can be formed by an extrusion process. The plurality of cooling channels can be extended in the X direction. The plurality of cooling channels can be spaced apart in the Y direction.

[0072] The cooling channels of the lid 150 can be connected to the upper injection pipe 163 and the upper recovery pipe 173. Cooling fluid introduced from the upper injection pipe 163 can flow through the cooling channels and be recovered by the upper recovery pipe 173.

[0073] A second TIM layer 133 can be interposed between the lid 150 and the battery cell assembly 120. The second TIM layer 133 may be a heat transfer pad. Each of the second TIM layers 133 can be separated from the plurality of battery cells 121. Each of the second TIM layers 133 can be in contact with the plurality of cooling fins 126. Each of the second TIM layers 133 can be in contact with the second portion 126H of the plurality of cooling fins 126. Each of the second TIM layers 133 can be in contact with the lid 150. The second portion 126H of each of the plurality of cooling fins 126 can be separated from the lid 150 with the second TIM layer 133 in between.

[0074] Conventional cooling solutions cover multiple battery cells 121 with a second TIM layer 133. In this case, the terraces 121T of the multiple battery cells 121 can form an air layer between the multiple battery cells 121 and the second TIM layer 133, which can reduce the cooling efficiency of the multiple battery cells 121.

[0075] According to an exemplary embodiment, multiple cooling fins 126 are provided that are in contact with multiple battery cells 121 and cover the terraces 121T of the multiple battery cells 121, so that the cooling channels of the base plate 111 and the cooling channels of the lid 150 can be used efficiently, and the cooling efficiency of the battery pack 100 can be improved. Furthermore, since the bottom of each of the multiple battery cells 121 is in direct contact with the first TIM layer 131, the cooling efficiency of the battery pack 100 can be further improved.

[0076] The battery pack 100 may further include an exhaust device coupled to the side wall 115. The exhaust device can delay heat propagation by expelling hot gases and flames from inside the battery pack 100 in the event of a thermal runaway event occurring inside the battery pack 100.

[0077] Here, thermal runaway of the multiple battery cell assemblies 120 is a state in which the temperature change of the multiple battery cell assemblies 120 is further accelerated, resulting in an uncontrollable positive feedback loop. In a thermal runaway state, the multiple battery cell assemblies 120 exhibit a rapid temperature increase and emit large amounts of high-pressure gas and combustion residue.

[0078] The battery pack 100 may further include electrical components. These electrical components may include any electronic elements necessary to power the battery pack. The electrical components may be placed on the electrical component mounting area (EMR).

[0079] Electrical components may include, for example, a Battery Management System (BMS). The BMS can be configured to monitor, balance, and control the battery pack. Monitoring of the battery pack 100 may include measuring the voltage and current at specific nodes within a plurality of battery cell assemblies 120 and measuring the temperature at a set location within the battery pack 100. The battery pack 100 may include measuring instruments for measuring the aforementioned voltage, current, and temperature.

[0080] Balancing the battery pack 100 is an operation that reduces deviations between multiple battery cell assemblies 120. Control of the battery pack 100 includes preventing 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.

[0081] The electrical components may further include a cooling system, a Power Relay Assembly (PRA), a safety plug, and the like. The cooling system may include a cooling fan. The cooling fan can prevent each of the multiple battery cell assemblies 120 from overheating by circulating air inside the battery pack 100. The PRA can be configured to supply or cut off power from the high-voltage battery to an external load (e.g., the vehicle's motor). The PRA can protect the multiple battery cell assemblies 120 and the external load (e.g., the vehicle's motor) by cutting off the power supply to the external load (e.g., the vehicle's motor) in situations where abnormal voltages occur, such as voltage surges.

[0082] The battery pack 100 may further include multiple exhaust devices. These exhaust devices can be installed on the lid 150 and any one of the side walls 112, 113, 114, or 115. The multiple exhaust devices can provide a path for releasing hot gases from inside the battery pack 100 to the outside in the event of a thermal runaway event occurring in part of the battery cell assembly 120. This can delay thermal propagation and improve the stability of the battery pack 100.

[0083] (Second Embodiment) Figure 6 is a cross-sectional view illustrating a battery cell assembly 120' according to another exemplary embodiment. More specifically, Figure 6 shows the portion corresponding to Figure 5. The battery cell assembly 120' can be replaced with the battery cell assembly 120 of Figure 3.

[0084] Referring to Figure 6, the battery cell assembly 120' may include multiple battery cells 121, multiple pads 122, a first circuit assembly 123 (see Figure 3), a second circuit assembly 124 (see Figure 3), a first crossbeam 125a (see Figure 3), a second crossbeam 125b (see Figure 3), and multiple cooling fins 127.

[0085] The multiple battery cells 121, multiple pads 122, the first circuit assembly 123 (see Figure 3), the second circuit assembly 124 (see Figure 3), the first crossbeam 125a (see Figure 3), and the second crossbeam 125b (see Figure 3) are substantially the same as those described with reference to Figures 1 to 5, so their redundant explanations will be omitted.

[0086] Each of the multiple cooling fins 127 can have high thermal conductivity. Each of the multiple cooling fins 127 can include a metallic material such as aluminum and stainless steel.

[0087] Each of the multiple cooling fins 127 may have an L-shape. The shape of each of the multiple cooling fins 127 may differ from a C-shape. Each of the multiple cooling fins 127 may include a first portion 127V substantially parallel to the Z direction and a second portion 127H substantially perpendicular to the Z direction. Each of the multiple cooling fins 127 may be separated from the first TIM layer 131 (see Figure 2) interposed between the multiple battery cells 121 and the base plate 111 (see Figure 2). Each of the multiple cooling fins 127 may not include a portion interposed between the multiple battery cells 121 and the base plate 111 (see Figure 2).

[0088] The length in the X direction of each second portion 127H of the multiple cooling fins 127 may differ from the length in the X direction of each of the multiple battery cells 121. The length in the X direction of each second portion 127H of the multiple cooling fins 127 may be longer than the length in the X direction of each of the multiple battery cells 121. This allows each second portion 127H of the multiple cooling fins 127 to cover two or more battery cells 121. The length in the X direction of each second portion 127H of the multiple cooling fins 127 may be less than N times the length in the X direction of each battery cell 121 (where N is the number of battery cells 121 covered by each of the multiple cooling fins 127). This prevents interference between the multiple cooling fins 127 when the multiple battery cells 121 are coupled together.

[0089] For example, as illustrated in Figure 6, when each second portion 127H of a plurality of cooling fins 127 covers two battery cells 121, the length in the X direction of each second portion 127H of the plurality of cooling fins 127 may be less than twice the length in the X direction of each battery cell 121.

[0090] The length in the Z direction of each first portion 127V of the multiple cooling fins 127 may differ from the length in the Z direction of each of the multiple battery cells 121. The length in the Z direction of each first portion 127V of the multiple cooling fins 127 may be longer than, but not limited to, the length in the Z direction of each of the multiple battery cells 121. The length in the Z direction of each first portion 127V of the multiple cooling fins 127 may be the same as, or shorter than, the length in the Z direction of each of the multiple battery cells 121.

[0091] Multiple cooling fins 127 can be interposed between multiple battery cells 121. Each first portion 127V of the multiple cooling fins 127 can be interposed between multiple battery cells 121. Each of the multiple cooling fins 127 can be coupled to a corresponding battery cell 121. According to an exemplary embodiment, the multiple battery cells 121 and the multiple cooling fins 127 can correspond in a many-to-one (e.g., 2 to 1) relationship.

[0092] According to an exemplary embodiment, one of a plurality of cooling fins 127 can be interposed between two adjacent battery cells 121. According to an exemplary embodiment, two or more of a plurality of battery cells 121 can be interposed between two adjacent cooling fins 127.

[0093] According to an exemplary embodiment, the multiple cooling fins 127 can be in contact with two of the multiple battery cells 121. This can improve the energy density of the battery cell assembly 120' compared to the case where the multiple cooling fins 127 are coupled to each of the multiple battery cells 121.

[0094] Multiple cooling fins 127 can be coupled to multiple battery cells 121. Multiple cooling fins 127 can be coupled to multiple battery cells 121, for example, by adhesive. Adhesive can be applied between each first portion 127V of the multiple cooling fins 127 and the multiple battery cells 121.

[0095] Each second portion 127H of the multiple cooling fins 127 can be separated from the multiple battery cells 121. Each second portion 127H of the multiple cooling fins 127 can cover the terrace 121T of the corresponding battery cell 121. Each second portion 127H of the multiple cooling fins 127 can cover two or more terraces 121T of the multiple battery cells 121.

[0096] (Third embodiment) Figure 7 is a flowchart illustrating how to assemble a battery pack 100 according to another exemplary embodiment.

[0097] Figure 8 is a perspective view illustrating how to assemble a battery pack 100 according to another exemplary embodiment.

[0098] Referring to Figures 2 and 7, a pack housing 110 can be provided at P110. Providing the pack housing 110 may include applying a first TIM layer 131 on the pack housing 110.

[0099] Referring next to Figures 2, 7, and 8, multiple battery cell assemblies 120 can be placed on the pack housing 110. To place multiple battery cell assemblies 120 on the pack housing 110, the first portion AP1 and the second portion AP2 of the multiple cooling fins 126 can be attracted, as shown in Figure 8. According to an exemplary embodiment, the multiple cooling fins 126 have relatively high rigidity and can therefore be used to transport the multiple battery cell assemblies 120 using attraction. Furthermore, since a uniform force is applied to each of the multiple battery cells 121 of the multiple battery cell assemblies 120 while each of the multiple battery cell assemblies 120 is being transported, damage to the multiple battery cells 121 during the assembly process of the battery pack 100 can be prevented.

[0100] Next, referring to Figures 1 and 7, the pack housing 110 and the lid 150 can be joined at P130. The pack housing 110 and the lid 150 can be joined by mechanical means such as bolting.

[0101] (Fourth Embodiment) Figure 9 shows a battery cell assembly 120'' according to another exemplary embodiment.

[0102] Figure 10 is a cross-sectional view along the cutting line 9I-9I' in Figure 9.

[0103] Figure 11 is a magnified partial cross-sectional view of part POR' of Figure 10.

[0104] Referring to Figures 9 to 11, each of the multiple battery cell assemblies 120 may include multiple battery cells 121, multiple pads 122, a first circuit assembly 123, a second circuit assembly 124, a first crossbeam 125a (see Figure 3), a second crossbeam 125b (see Figure 3), and multiple cooling fins 126, 126'.

[0105] The multiple battery cells 121, multiple pads 122, first circuit assembly 123, second circuit assembly 124, first crossbeam 125a (see Figure 3), second crossbeam 125b (see Figure 3), and multiple cooling fins 126 are substantially the same as those described with reference to Figures 1 to 5, so their redundant descriptions are omitted.

[0106] Multiple cooling fins 126' can be arranged along the edges in the X direction. Each of the multiple cooling fins 126' can include a pinhole 126PH. Each pinhole 126PH of the multiple cooling fins 126' can partially expose adjacent battery cells 121.

[0107] In Figure 7, at P120, when the battery cell assembly 120'' is placed on the pack housing 110, each of the pinholes 126PH of the multiple cooling fins 126' can be used. Each of the pinholes 126PH of the multiple cooling fins 126' can be used to transport the battery cell assembly 120''. More specifically, a lifting jig can be inserted into the multiple cooling fins 126' through each of the pinholes 126PH of the multiple cooling fins 126', and the battery cell assembly 120' can be transported.

[0108] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

Claims

1. A pack housing including a base plate and side walls, A plurality of battery cell assemblies arranged on the base plate, A plurality of first TIM (thermal interface material) layers interposed between the plurality of battery cell assemblies and the pack housing, A lid attached to the side wall, It includes a second TIM layer interposed between the lid and the plurality of battery cell assemblies, Each of the aforementioned plurality of battery cell assemblies is Multiple battery cells arranged along a first direction, Interposed between the plurality of battery cells are a plurality of L-shaped cooling fins, The sealed portion is the terrace, and A battery pack comprising the plurality of cooling fins, each covering the terrace of a corresponding battery cell.

2. The battery pack according to claim 1, wherein each of the plurality of cooling fins includes a first portion perpendicular to the first direction and a second portion connected to the first portion and parallel to the first direction.

3. The battery pack according to claim 2, wherein the length of the second portion of each of the plurality of cooling fins in the first direction is different from the length of the plurality of battery cells in the first direction.

4. The battery pack according to claim 2, wherein the length of the second portion of each of the plurality of cooling fins in the first direction is shorter than the length of the plurality of battery cells in the first direction.

5. The battery pack according to claim 2, wherein the length of the second portion of each of the plurality of cooling fins in the first direction is longer than the length of the plurality of battery cells in the first direction.

6. The battery pack according to claim 2, wherein the length of the second portion of each of the plurality of cooling fins in the first direction is shorter than twice the length of the plurality of battery cells in the first direction.

7. The battery pack according to claim 2, wherein the second TIM layer is in contact with the second portion of the plurality of cooling fins of the plurality of battery cell assemblies and the lid.

8. The battery pack according to claim 7, wherein the second portion of the plurality of cooling fins is separated from the lid with the second TIM layer in between.

9. The battery pack according to claim 1, wherein each of the terraces of the plurality of battery cells is separated from the second TIM layer.

10. The battery pack according to claim 1, wherein each of the plurality of cooling fins is made of aluminum or stainless steel.

11. The battery pack according to claim 1, wherein each of the plurality of cooling fins is fixed to a corresponding of the plurality of battery cells by adhesive.

12. The battery pack according to claim 1, wherein the shape of each of the plurality of cooling fins is different from that of a C.

13. The battery pack according to claim 1, wherein each of the plurality of cooling fins is separated from the base plate.

14. The battery pack according to claim 1, wherein each of the plurality of cooling fins is separated from the first TIM layer.

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