Battery pack case and battery pack including the same

Abstract

According to an exemplary embodiment, a battery pack housing is provided. The battery pack housing includes a bottom plate, a cross beam on the bottom plate, and a plurality of hybrid bolts coupled to the bottom plate and the cross beam, wherein each hybrid bolt of the plurality of hybrid bolts includes a bolt including a shank and a flange, and a first coating applied to the shank.

Description

Technical Field

[0001] This disclosure relates to a battery pack housing and a battery pack including the battery pack housing. This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0144768, filed on October 22, 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 a power source for various types of wireless devices, such as mobile phones, laptops, and cordless vacuum cleaners. Recently, the primary use of secondary batteries is shifting from mobile devices to mobility tools, as the manufacturing cost per unit capacity of secondary batteries has decreased dramatically due to improvements in energy density and economies of scale, and as the driving range of battery electric vehicles (BEVs) has increased to the same level as that of fuel cell vehicles.

[0003] The technological trend in secondary batteries used in transportation vehicles is towards increased energy density and safety. The safety of secondary batteries in transportation vehicles is directly related to passenger lives and is therefore extremely important. In the event of thermal runaway, the safety of secondary batteries can be achieved through mechanical robustness, reliable electrical insulation, and delay in thermal transfer. Summary of the Invention

[0004] Technical issues

[0005] This disclosure aims to provide a battery pack housing with improved safety and a battery pack including the battery pack housing.

[0006] Technical solution

[0007] Embodiments of this disclosure provide a battery pack housing. The battery pack housing includes: a base plate; a crossbeam located on the base plate; and a plurality of hybrid bolts connected to the base plate and the crossbeam, wherein each of the plurality of hybrid bolts includes: a bolt, the bolt including a shank and a flange; and a first coating applied to the shank.

[0008] The first coating may include a resin.

[0009] The first coating may include a heat-fusible material.

[0010] The first coating may include one of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polysulfone.

[0011] The melting point of the first coating may be different from the melting point of the bolt.

[0012] The melting point of the first coating may be lower than that of the bolt.

[0013] Each of the plurality of hybrid bolts may include a second coating applied to the shank.

[0014] The second coating may include a material different from that of the first coating.

[0015] The melting point of the second coating may be different from that of the first coating.

[0016] The melting point of the second coating may be higher than that of the first coating.

[0017] The second coating may include one of epoxy resin, polyurethane, silicone resin, polyimide, fluororesin and metal oxide.

[0018] The first coating may be located between the crossbeam and the bolt.

[0019] The second coating may be located between the base plate and the bolt.

[0020] The battery pack housing may also include a plurality of nuts inserted between the crossbeam and the base plate.

[0021] The crossbeam can be spaced apart from the base plate.

[0022] Each of the plurality of nuts can be welded to the base plate.

[0023] Each of the plurality of hybrid bolts can be fastened to a corresponding nut among the plurality of nuts.

[0024] The second coating may be located between the bolt and a corresponding nut among the plurality of nuts.

[0025] Beneficial effects

[0026] According to embodiments of this disclosure, the first coating on the hybrid bolt can melt when a thermal runaway event occurs in the battery cell assembly. Therefore, the base plate and crossbeam can be separated to ensure venting space between them, thereby delaying heat propagation and improving the safety of the battery pack housing and the battery pack including the housing.

[0027] The effects achievable by the embodiments of this disclosure are not limited to those described above, and those skilled in the art to which the embodiments of this disclosure pertain will clearly derive and understand other effects not described herein based on the following description. In other words, those skilled in the art can derive unexpected effects achieved in implementing the embodiments of this disclosure. Attached Figure Description

[0028] Figure 1 This is a plan view of the battery pack according to the implementation method.

[0029] Figure 2 It is along Figure 1 The cross-sectional view taken from line 1A-1A'.

[0030] Figure 3 It is along Figure 1 The cross-sectional view taken from line 1B-B'.

[0031] Figure 4 This is a plan view of the battery pack according to the implementation method.

[0032] Figure 5 It is along Figure 4 The cross-sectional view taken from line 4A-4A'.

[0033] Figure 6 It is along Figure 4 The cross-sectional view taken from line 4B-4B'. Detailed Implementation

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

[0035] Therefore, the embodiments described herein and the configurations shown in the accompanying drawings are merely examples 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 these configurations as of the date of filing 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 well-known configuration or function related to the description of this disclosure will not be described in detail.

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

[0038] (First and Second Embodiments)

[0039] Figure 1 This is a plan view of the battery pack according to the implementation method.

[0040] Figure 2 It is along Figure 1 The cross-sectional view taken from line 1A-1A'.

[0041] Figure 3 It is along Figure 1 The cross-sectional view taken from line 1B-B'.

[0042] refer to Figures 1 to 3 The battery pack 100 may include a battery pack housing 110, a plurality of battery cell assemblies 120, and a support structure 130. The battery pack 100 may be the final product to be installed in an application such as a vehicle.

[0043] The battery pack housing 110 provides space for mounting multiple battery cell assemblies 120. The battery pack housing 110 may include a base plate 111, side walls 112, a central beam 113, a crossbeam 114, and multiple hybrid bolts 115.

[0044] Here, the two directions substantially parallel to the mounting surface 111M of the base plate 111 are defined as the X-axis direction and the Y-axis direction, and the direction substantially perpendicular to the mounting surface 111M of the base plate 111 is defined as the Z-axis direction. The X-axis direction, Y-axis direction, and Z-axis direction may be substantially perpendicular to each other. The mounting surface 111M may face multiple battery cell assemblies 120. The base plate 111 may have a flat plate shape. The base plate 111 may include metal.

[0045] Sidewall 112 may be located on the edge of base plate 111. Sidewall 112 may be attached to base plate 111. Sidewall 112 may be fixed to base plate 111 by bolts or welding. Sidewall 112 may horizontally surround multiple battery cell assemblies 120. Sidewall 112 may include metal.

[0046] The central beam 113 may extend along the X-axis. The central beam 113 may be surrounded by the sidewall 112. The central beam 113 may be connected to the base plate 111. The central beam 113 may be fixed to the base plate 111 by welding or bolting. The central beam 113 may include metal.

[0047] Each crossbeam 114 may extend along the Y-axis. The crossbeam 114 may be surrounded by sidewalls 112. The crossbeam 114 may be connected to the base plate 111. A central beam 113 may be located between the crossbeams 114. The crossbeams 114 may comprise metal.

[0048] Each crossbeam 114 may include a plurality of holes 114H. Each crossbeam 114 may have a solid structure. The plurality of holes 114H may be formed by machining the crossbeam 114. Each of the plurality of holes 114H may extend from the lower surface of the crossbeam 114. The lower surface of the crossbeam 114 may face the mounting surface 111M.

[0049] In the following text, the width of a component can be understood as the width of the component in a direction parallel to the mounting surface 111M of the base plate 111. For example, the width can be the length in the X-axis direction, the length in the Y-axis direction, and the length in a direction parallel to the mounting surface 111M and inclined to each of the X-axis and Y-axis directions.

[0050] Each of the plurality of hybrid bolts 115 can be connected to a corresponding crossbeam 114 and a base plate 111. Each of the plurality of hybrid bolts 115 can be tightened to a corresponding crossbeam 114 and a base plate 111. The crossbeam 114 can be fixed to the base plate 111 by the plurality of hybrid bolts 115.

[0051] Each of the plurality of hybrid bolts 115 may pass through the base plate 111. Each of the plurality of hybrid bolts 115 may include a portion located in a corresponding hole among the plurality of holes 111H. Each of the plurality of hybrid bolts 115 may pass through a corresponding crossbeam 114. Each of the plurality of hybrid bolts 115 may include a portion located in a corresponding hole among the plurality of holes 114H.

[0052] Each of the plurality of hybrid bolts 115 may include a bolt 115B, a first coating 115C1, and a second coating 115C2. Bolt 115B may include a flange 115F and a shank 115S. The width of the flange 115F may differ from the width of the shank 115S. The width of the flange 115F may be greater than the width of the shank 115S. Bolt 115B may include metal.

[0053] Flange 115F may contact the bottom surface 111B of base plate 111. The bottom surface 111B of base plate 111 may be opposite to mounting surface 111M. Flange 115F may be spaced apart from mounting surface 111M.

[0054] The rod portion 115S may include threads, so that the bolt 115B can be fastened to a corresponding crossbeam in the base plate 111 and the crossbeam 114. The bolt 115B may include a recess 115BP. The recess 115BP may be located in the rod portion 115S.

[0055] The first coating 115C1 may be applied to the bolt 115B. The first coating 115C1 may be applied to the shank 115S of the bolt 115B. The first coating 115C1 may comprise a material having a low melting point. The first coating 115C1 may comprise a resin. The first coating 115C1 may comprise polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polysulfone.

[0056] The first coating 115C1 may include a heat-fusible material. The melting point of the first coating 115C1 may be different from the melting point of the bolt 115B. The melting point of the first coating 115C1 may be lower than the melting point of the bolt 115B.

[0057] The second coating 115C2 can be applied to the bolt 115B. The second coating 115C2 can be applied to the shank 115S of the bolt 115B. The location where the second coating 115C2 is applied can be different from the location where the first coating 115C1 is applied. The second coating 115C2 can be closer to the flange 115F than the first coating 115C1.

[0058] The rod portion 115S may include a portion to which only the first coating 115C1 is applied and a portion to which only the second coating 115C2 is applied. The second coating 115C2 may partially overlap with the first coating 115C1. The first coating 115C1 may be located between the bolt 115B and a corresponding crossbeam in the crossbeam 114. The second coating 115C2 may be located between the bolt 115B and the base plate 111.

[0059] The second coating 115C2 may include a material different from that of the first coating 115C1. The second coating 115C2 may include a resin. The second coating 115C2 may include epoxy resin, polyurethane, silicone resin, polyimide, fluoropolymer, or metal oxide. The melting point of the second coating 115C2 may differ from the melting point of the first coating 115C1. The melting point of the second coating 115C2 may be higher than that of the first coating 115C1.

[0060] When thermal runaway occurs in adjacent battery cell assemblies of the plurality of battery cell assemblies 120, the first coating 115C1 can melt. Here, thermal runaway is a state in which the temperature change of the plurality of battery cell assemblies 120 accelerates the temperature change, i.e., an uncontrollable positive feedback. In a state of thermal runaway, the temperature of the plurality of battery cell assemblies 120 rises sharply, and a large amount of high-pressure gas and burning debris is released from them. According to an embodiment, in a thermal runaway event, the first coating 115C1 melts, thus allowing the base plate 111 and the crossbeam 114 to separate, and facilitating venting through the space between the base plate 111 and the crossbeam 114, thereby delaying or preventing heat propagation. Therefore, the safety of the battery pack 100 can be improved.

[0061] In the event of thermal runaway, the first coating 115C1 can melt, thereby facilitating the separation of the bolt 115B and the beam 114, and the second coating 115C2 can prevent oxygen inflow and flame release. The second coating 115C2 can be a heat-locking coating.

[0062] The support structure 130 can be connected to the crossbeam 114. The support structure 130 can be fixed to the crossbeam 114. Multiple battery cell assemblies 120 can be supported by the support structure 130.

[0063] Each of the support structures 130 may include a mounting portion 131 that overlaps with a corresponding crossbeam of the crossbeam 114 in the Z-axis direction, a support portion 133 that overlaps with a corresponding battery cell assembly of the plurality of battery cell assemblies 120 in the Z-axis direction, and a connecting portion 135 that connects the mounting portion 131 and the support portion 133. The connecting portion 135 may be substantially perpendicular to the X-axis direction.

[0064] Mounting part 131 can be connected to crossbeam 114. Mounting part 131 can be fixed to crossbeam 114 by welding or bolting. Mounting part 131 can be substantially perpendicular to the Z-axis direction.

[0065] The support portion 133 may be closer to the base plate 111 than the mounting portion 131. The support portion 133 may support a corresponding battery cell assembly among the plurality of battery cell assemblies 120. The support portion 133 may include a plurality of vent holes 130H exposing the lower part of the corresponding battery cell assembly among the plurality of battery cell assemblies 120. The support portion 133 may be substantially perpendicular to the Z-axis direction. The support portion 133 may be spaced apart from the base plate 111. The support portion 133 may be inserted between the base plate 111 and the corresponding battery cell assembly among the plurality of battery cell assemblies 120.

[0066] The central beam 113 and the crossbeam 114 can isolate multiple battery cell assemblies 120 from each other. The multiple battery cell assemblies 120 can be spaced apart in the Y-axis direction by means of the central beam 113 inserted therebetween. The central beam 113 can be inserted between the multiple battery cell assemblies 120. The multiple battery cell assemblies 120 can be spaced apart in the X-axis direction by means of the crossbeam 114 inserted therebetween. The crossbeam 114 can be inserted between the multiple battery cell assemblies 120.

[0067] exist Figure 1 In this configuration, the array of multiple battery cell components 120 can be a 3×2 array. Figure 1 The array of multiple battery cell assemblies 120 is a non-limiting example and should not be construed as limiting the technical concept of this disclosure in any way. Based on the above description, those skilled in the art will be able to readily derive multiple battery cell assemblies 120 arranged in an M×N array (where M and N are each integers of 2 or greater).

[0068] Multiple battery cell assemblies 120 can be mounted on the support structure 130. The multiple battery cell assemblies 120 can be spaced apart from the base plate 111. Therefore, venting space can be provided between the base plate 111 and the support structure 130. Each of the multiple battery cell assemblies 120 may include multiple battery cells, multiple pads, and a first integrated circuit assembly and a second integrated circuit assembly.

[0069] Each of a plurality of battery cells may include an electrode assembly, an electrolyte, and a housing. Each of the plurality of battery cells may be a cylindrical battery cell, a prismatic battery cell, or a pouch battery cell. The electrode assembly of a cylindrical battery cell is embedded in a cylindrical metal can. The electrode assembly of a prismatic battery cell is embedded in a prismatic metal can. The electrode assembly of a pouch battery cell is embedded in a pouch housing comprising aluminum laminates.

[0070] Electrode assemblies may include a positive electrode, a negative electrode, and a separator located between the positive and negative electrodes. A wound-core type electrode assembly may include a structure in which the positive electrode, negative electrode, and separator located between the positive and negative electrodes are wound together. A stacked type electrode assembly may include multiple positive electrodes and multiple negative electrodes stacked sequentially, and multiple separators inserted between the positive and negative electrodes.

[0071] According to the implementation, multiple battery cells can form multiple groups. Multiple groups may include one or more battery cells connected in parallel. Multiple groups may be connected in series with each other. The number of battery cells in each of the multiple groups and the number of groups connected in series with each other can be determined by the voltage and current output through each battery cell assembly in the multiple battery cell assemblies 120.

[0072] According to one embodiment, each of the plurality of pads may include a compressible material. The plurality of pads may be interposed between a plurality of battery cells. The plurality of pads may absorb the expansion of the plurality of battery cells. According to one embodiment, the plurality of pads may be a thermal barrier.

[0073] The first integrated circuit assembly may include an insulating frame, an integrated circuit, a busbar, wires, and an insulating cover. The integrated circuit assembly may include physical and functional components to provide electrical connections between multiple battery cells, output the resulting voltages of the multiple battery cells, and measure the voltage (or current) at nodes within a circuit composed of the multiple battery cells.

[0074] The insulating frame can include insulating materials such as plastic. It can cover the front of multiple battery cells. The insulating frame can support integrated circuits, busbars, and wires.

[0075] The busbar can be shorted to the positive lead of the battery cells in the first group and the negative lead of one or more battery cells in the last group. The busbar can be soldered to the positive lead of the battery cells in the first group and the negative lead of one or more battery cells in the last group. The voltage of multiple battery cells in each of the multiple battery cell assemblies 120 can be output through the busbar. The busbar can be fixed to the insulating frame.

[0076] The integrated circuit can be mounted on an insulating frame. The positive and negative leads, soldered together, can form nodes within each of the multiple battery cell assemblies 120. The integrated circuit can be configured to measure the voltage of the nodes via sensing plates and sensing strips.

[0077] The sensing strip may include a conductive material. The sensing strip may have a rod shape. The sensing strip may be shorted to a busbar. The sensing strip may be connected to a busbar. The voltage of the busbar can be measured through the sensing strip.

[0078] Each sensing plate can be in patch or pad shape. The sensing plate may include conductive material. The sensing plate can be shorted to one of the corresponding positive and negative leads of multiple battery cells.

[0079] Each sensing board can be connected to an integrated circuit. The voltage of multiple nodes within multiple battery cell assemblies 120 can be measured using the sensing boards.

[0080] The insulating cover may include insulating materials, such as plastic. The insulating cover may be interference-fitted into the insulating frame. The insulating cover may cover the integrated circuit and busbar, thus protecting the electrical components of the first and second integrated circuit assemblies.

[0081] The second integrated circuit assembly may include an insulating frame, an integrated circuit, a busbar, wires, and an insulating cover. Except that the second integrated circuit assembly does not include a busbar, it is substantially the same as the first integrated circuit assembly.

[0082] The battery pack 100 may also include a cover attached to the sidewall 112 of the battery pack housing 110. The cover may cover components inside the battery pack 100, such as battery cell assemblies 120 and electronic components. The cover may be secured to the battery pack housing 110 by a mechanical coupling such as bolts.

[0083] The battery pack 100 may also include a venting device coupled to the battery pack housing 110 or cover. The battery pack housing 110 or cover may include a vent hole connected to the venting device. The venting 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 the plurality of battery cell assemblies 120.

[0084] 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 at certain nodes in the plurality of battery cell assemblies 120 and measuring the temperature at a set location in the battery pack 100. The battery pack 100 may include measuring devices for measuring the voltage, current, and temperature as described above.

[0085] Balancing the battery pack 100 is an operation to reduce deviations among the multiple battery cell assemblies 120. Controlling 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 to prevent a reduction in the lifespan of each of the multiple battery cell assemblies 120.

[0086] 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 each of the multiple battery cell assemblies 120 from overheating. The PRA can be configured to supply or disconnect power from the high-voltage battery to an external load (e.g., the 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 and the external load.

[0087] The battery pack 100 may also include a plurality of intermediary busbars configured to electrically connect a plurality of battery cell assemblies 120. The plurality of battery cell assemblies 120 may be connected in series via the plurality of intermediary busbars. Therefore, the battery pack 100 may be configured to output a high voltage to an external load (e.g., a vehicle motor).

[0088] (Third and Fourth Embodiments)

[0089] Figure 4 This is a plan view of the battery pack 100' according to the embodiment.

[0090] Figure 5 It is along Figure 4 The cross-sectional view taken from line 4A-4A'.

[0091] Figure 6 It is along Figure 4 The cross-sectional view taken from line 4B-4B'.

[0092] refer to Figures 4 to 6The battery pack 100' may include a battery pack housing 110', multiple battery cell assemblies 120, and a support structure 130. The battery pack 100' may be a final product installed in an application such as a vehicle. The battery cell assemblies 120 and the support structure 130 are referenced above. Figures 1 to 3 The descriptions are essentially the same, so redundant descriptions are omitted here.

[0093] The battery pack housing 110' provides space for mounting multiple battery cell assemblies 120. The battery pack housing 110' may include a base plate 111, side walls 112, a central beam 113, a crossbeam 114, multiple hybrid bolts 115, and multiple nuts 116. The base plate 111, side walls 112, central beam 113, crossbeam 114, and multiple hybrid bolts 115 are as described above. Figures 1 to 3 The descriptions are essentially the same, so redundant descriptions are omitted here.

[0094] Each of the plurality of nuts 116 may be located between a base plate 111 and a corresponding crossbeam 114. Each crossbeam 114 may be spaced apart from the base plate 111. Each of the plurality of nuts 116 may be welded to the base plate 111. Liquid seals for the plurality of holes 111H in the base plate 111 may be provided by the plurality of nuts 116. The inner surfaces of the plurality of nuts 116 may include threads for fastening with a plurality of hybrid bolts 115. Each of the plurality of nuts 116 may include metal.

[0095] The melting point of the first coating 115C1 may be different from the melting point of each of the plurality of nuts 116. The melting point of the first coating 115C1 may be lower than the melting point of each of the plurality of nuts 116. The second coating 115C2 may be located between the bolt 115B and a corresponding nut of the plurality of nuts 116.

[0096] 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 to these configurations have been made as of the filing date of this application.

Claims

1. A battery pack housing, the battery pack housing comprising: Base plate; A crossbeam, which is located on the base plate; as well as Multiple hybrid bolts are used to connect the base plate and the crossbeam. Each of the plurality of hybrid bolts comprises: a bolt, the bolt including a shank and a flange; and a first coating applied to the shank.

2. The battery pack housing according to claim 1, wherein, The first coating comprises a resin.

3. The battery pack housing according to claim 1, wherein, The first coating comprises a heat-fusible material.

4. The battery pack housing according to claim 1, wherein, The first coating comprises one of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polysulfone.

5. The battery pack housing according to claim 1, wherein, The melting point of the first coating is different from the melting point of the bolt.

6. The battery pack housing according to claim 1, wherein, The melting point of the first coating is lower than that of the bolt.

7. The battery pack housing according to claim 1, wherein, Each of the plurality of hybrid bolts includes a second coating applied to the shank.

8. The battery pack housing according to claim 7, wherein, The second coating comprises a material different from that of the first coating.

9. The battery pack housing according to claim 7, wherein, The melting point of the second coating is different from that of the first coating.

10. The battery pack housing according to claim 7, wherein, The melting point of the second coating is higher than that of the first coating.

11. The battery pack housing according to claim 7, wherein, The second coating comprises one of epoxy resin, polyurethane, silicone resin, polyimide, fluororesin and metal oxide.

12. The battery pack housing according to claim 7, wherein, The first coating is located between the crossbeam and the bolt.

13. The battery pack housing according to claim 7, wherein, The second coating is located between the base plate and the bolt.

14. The battery pack housing according to claim 7, wherein the battery pack housing further comprises a plurality of nuts inserted between the crossbeam and the base plate.

15. The battery pack housing according to claim 14, wherein, The crossbeam is spaced apart from the base plate.

16. The battery pack housing according to claim 14, wherein, Each of the plurality of nuts is welded to the base plate.

17. The battery pack housing according to claim 14, wherein, Each of the plurality of hybrid bolts is fastened to a corresponding nut among the plurality of nuts.

18. The battery pack housing according to claim 14, wherein, The second coating is located between the bolt and a corresponding nut among the plurality of nuts.

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