Power battery pack structure, assembling method and automobile

Abstract

This invention relates to a power battery pack structure, assembly method, and automobile. The battery pack includes a housing, within which a cell assembly is disposed. The cell assembly includes multiple cell units arranged along a first direction, with a flexible and heat-insulating first heat-insulating sheet bonded between adjacent cell units. Each cell unit includes multiple cell groups arranged along the first direction, with a liquid cooling plate bonded between adjacent cell groups. Each cell group includes multiple cells arranged along a second direction, with a flexible and heat-insulating second heat-insulating sheet bonded between adjacent cells. The second direction is perpendicular to the first direction. A flow channel is provided on the inner side of the liquid cooling plate, with both ends of the flow channel connected to a cooling medium circulation pipeline. The battery pack structure of this invention has high overall energy density and good overall strength and rigidity.

Description

Technical Field

[0001] This invention relates to the field of power battery technology for new energy vehicles, specifically to a power battery pack structure, assembly method, and vehicle. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] In current power battery pack structures, cells are cooled using liquid cooling plates. For example, one liquid-cooled battery pack discloses a cooling structure where cells are distributed on both sides of a long strip-shaped liquid cooling plate. However, the liquid cooling plate only contacts the smallest side of the cell for heat exchange, while the largest surface area of ​​the prismatic cell is not involved in the cooling, thus limiting the overall cooling effect. Another battery module arranges cells on both sides of a long strip-shaped liquid cooling plate, with the largest surface area of ​​the prismatic cell participating in the cooling. However, no heat insulation sheets are placed between the cells, failing to eliminate the heat generation effect between adjacent cells. Furthermore, this battery module has end plates of the same length on both sides of the cells, and each battery module is independently assembled into the battery box using bolts. Gaps or beams are required between identical modules, affecting the overall strength and rigidity of the battery pack, as well as space utilization and energy density. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a power battery pack structure, assembly method and automobile, which overcomes the defects of the current power battery pack.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a power battery pack structure, including a housing, a cell assembly disposed within the housing, the cell assembly including a plurality of cell units arranged along a first direction, a flexible and heat-insulating first heat-insulating sheet bonded between adjacent cell units, a cell unit including a plurality of cell groups arranged along the first direction, a liquid cooling plate bonded between adjacent cell groups, a cell group including a plurality of cell units arranged along a second direction, a flexible and heat-insulating second heat-insulating sheet bonded between adjacent cell units, the second direction being perpendicular to the first direction, and a flow channel disposed on the inner side of the liquid cooling plate, the two ends of the flow channel being connected to a cooling medium circulation pipeline.

[0006] Optionally, along the first direction, anti-expansion crossbeams are provided on both sides of the battery cell assembly. The anti-expansion crossbeams are fixedly connected to the housing, and a heat-insulating flexible sheet is provided between the anti-expansion crossbeams and the battery cell assembly.

[0007] Optionally, the thermal insulation flexible sheet may be made of thermal insulation rubber.

[0008] Optionally, the first and second heat insulation sheets may be made of MMP-type foam pads, silicone foam pads, or aerogel pads.

[0009] Optionally, the cooling medium circulation pipeline includes cavity components disposed on both sides of the liquid cooling plate. The cavity components are connected to the flow channel. The cavity components are provided with joints on the front and rear sides. The joints of the cavity components on the same side of adjacent liquid cooling plates are connected by connectors. The cavity component on one side of the liquid cooling plate at one end is connected to the cooling medium inlet pipe disposed on the shell through a pipeline, and the cavity component on the other side is connected to the cooling medium outlet pipe disposed on the shell through a pipeline.

[0010] Optionally, the connector is a connector tube that communicates with the internal space of the cavity component. Correspondingly, the connecting component is a sleeve. In two adjacent connector tubes, one end of the sleeve is sealed around the outer circumference of one connector tube, and the other end is sealed around the outer circumference of the other connector tube.

[0011] Optionally, the cross-section of the flow channel is S-shaped or oblique rhombus.

[0012] Optionally, the bottom surface of the battery cell assembly is bonded to the bottom surface of the housing using structural adhesive.

[0013] Secondly, embodiments of the present invention provide a method for assembling the power battery pack structure described in the first aspect, comprising the following steps: Multiple battery cells are arranged and bonded together along the second direction, and a second heat insulation sheet is bonded between adjacent battery cells to complete the preparation of the battery cell assembly. The prepared battery cell assembly is bonded to both sides of the liquid cooling plate to complete the preparation of the battery cell unit; Multiple battery cell units are arranged and bonded together along a first direction, and a first heat insulation sheet is bonded between adjacent battery cell units to complete the preparation of the battery cell assembly. The battery cell assembly is fixed inside the housing, and a cooling medium circulation pipeline connected to the liquid cooling plate channel is assembled.

[0014] Thirdly, embodiments of the present invention provide a vehicle equipped with the power battery pack structure described in the first aspect.

[0015] The beneficial effects of this invention are as follows: 1. The battery pack structure and assembly method of the present invention include a battery cell assembly on both sides of a liquid cooling plate to form a battery cell unit. The liquid cooling plate contacts the long side of the battery cell in the battery cell unit, which provides good cooling effect for the battery cell. Multiple battery cell units are arranged along a first direction. After a first heat insulation sheet is set between adjacent battery cell units, the multiple battery cell units and the first heat insulation sheet are bonded and fixed together. The resulting battery cell assembly is then fixed inside the housing. Compared with the traditional method of setting end plates around multiple battery cell units to form a battery cell module, and then fixing each battery cell module independently inside the housing, the multiple battery cell units are pre-bonded and extruded and fixed. When installed inside the housing, there is no need to set gaps or beams between adjacent battery cell units, which increases the utilization rate of the space inside the housing and increases the overall energy density. At the same time, the multiple battery cell units form an integral structure, which improves the overall strength and rigidity of the battery pack structure.

[0016] 2. The battery pack structure of the present invention includes a flexible and heat-insulating first heat-insulating sheet and a second heat-insulating sheet. The first heat-insulating sheet and the second heat-insulating sheet can effectively eliminate the heat generation effect of adjacent battery cells, and at the same time absorb the expansion generated during the use of the battery cells, thus playing a role in protecting the battery cells from compression and improving the safety of battery cell use. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the battery cell unit structure in Embodiment 1 of the present invention; Figure 3 This is an exploded view of the battery cell unit in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the assembly of the square-shell battery cell with the first heat insulation sheet and the second heat insulation sheet in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the liquid cooling plate structure in Embodiment 1 of the present invention; Figure 6 This is a schematic cross-sectional view of the liquid cooling plate in Embodiment 1 of the present invention; Among them, 1. shell, 2. battery cell unit, 3. first heat insulation sheet, 4. cooling medium inlet for battery cell area, 5. cooling medium outlet for battery cell area; 11. Front anti-expansion crossbeam, 12. Middle anti-expansion crossbeam, 13. Rear anti-expansion crossbeam, 14. Bottom support plate, 15. Cooling medium inlet, 16. Cooling medium outlet; 21. Battery cell; 22. Liquid cooling plate; 23. Second heat insulation sheet; 24. Connecting water jacket; 221. Plate body, 222. Joint. Detailed Implementation

[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] Example 1 This embodiment provides a power battery pack structure, such as Figure 1 As shown, the device includes a housing 1, and a battery cell assembly is disposed inside the housing 1. The number of battery cell assemblies can be set according to actual needs. The battery cell assembly can be set to one, two or more. In this embodiment, the number of battery cell assemblies is set to two.

[0022] The bottom surface of the battery cell assembly 1 is bonded and fixed to the surface of the bottom support plate 14 of the housing 1 by structural adhesive. The battery cell assembly includes multiple battery cell units 2 arranged along a first direction. A first heat insulation sheet 3 is provided between adjacent battery cell units 2. The first heat insulation sheet 3 is made of flexible heat insulation material.

[0023] Preferably, the first heat insulation sheet 3 is made of MMP-type foam pad, silicone foam pad, or aerogel pad. Those skilled in the art can choose according to actual needs, and will not be described in detail here.

[0024] The first heat insulation sheet 3 is bonded and fixed to the battery cell units 2 on both sides. The bonding and fixing method ensures the integrity and stability of the structure and avoids the loosening or displacement of components due to vibration during vehicle operation, thereby ensuring the long-term reliability of the battery pack. By setting the first heat insulation sheet 3, not only is the electrical insulation between the battery cell units 2 guaranteed, but the heat transfer along the first direction is also effectively blocked, preventing the spread of thermal runaway between the battery cell units 2 and greatly improving the safety of the battery pack.

[0025] like Figures 2-3 As shown, the battery cell unit 2 includes multiple battery cell groups, which are arranged along a first direction. A liquid cooling plate 22 is provided between adjacent battery cell groups, and the battery cell groups are bonded and fixed to the liquid cooling plate 22.

[0026] In this embodiment, the battery cell unit includes two battery cell groups, and there is also a liquid cooling plate 22 between the two battery cell groups.

[0027] The liquid cooling plate 22 is made of aluminum alloy plate and has flow channels inside for introducing cooling medium. The introduced cooling medium can cool the battery cells on both sides of the liquid cooling plate 22 and remove the heat generated by the battery cells 21 during operation. At the same time, the aluminum alloy plate has a certain degree of flexibility and can absorb the slight expansion and deformation generated by the battery cells during long-term operation.

[0028] The flow channel is provided in multiple ways, such as Figure 6 As shown, the cross-section of the flow channel is S-shaped or oblique rhombus. The S-shaped flow channel can increase the turbulence of the cooling medium and improve the heat exchange efficiency; while the oblique rhombus cross-section can enhance the structural strength of the flow channel and resist internal pressure while ensuring the flow area.

[0029] Those skilled in the art can set the shape of the flow channel according to actual needs, which will not be described in detail here.

[0030] The two ends of the flow channel of the liquid cooling plate 22 are connected to the cooling medium circulation pipeline. The cooling medium circulation pipeline is used to inject the cooling medium into the flow channel and receive the cooling medium after heat exchange flowing out of the flow channel.

[0031] The battery cell assembly includes multiple battery cells 21 arranged along the second direction. A second heat insulation sheet 23 is provided between adjacent battery cells 21. The battery cells 21 are bonded and fixed to the second heat insulation sheet 23, and the outer surfaces of the battery cells 21 located at both ends, perpendicular to the second direction, are also bonded with the second heat insulation sheet 23.

[0032] The second direction is perpendicular to the first direction.

[0033] In this embodiment, the battery cell group includes six battery cells 21 arranged along the second direction. It is understood that those skilled in the art can set the number of battery cells 21 in the battery cell group according to actual needs, and will not be described in detail here.

[0034] The second heat insulation sheet 23 is made of flexible heat insulation material.

[0035] Preferably, the second heat insulation sheet 23 is made of MMP-type foam pad, silicone foam pad, or aerogel pad.

[0036] MMP-type foam pads have excellent cushioning and shock absorption properties, effectively dispersing impact forces and protecting the battery cells. Moreover, compared to silicone foam pads and aerogel pads, they have lower production costs and better economic benefits.

[0037] Silicone foam pads have a wide operating temperature range, good weather resistance and anti-aging properties, long service life, and strong chemical stability.

[0038] Aerogel pads offer better thermal insulation and are lighter than MMP-type foam pads and silicone foam pads.

[0039] Those skilled in the art can choose according to their actual needs, and will not be described in detail here.

[0040] In this embodiment, the battery cell 21 is a square-shell battery cell with a cuboid structure. Among its four sides perpendicular to the bottom surface of the shell 1, the two sides with the longer length and larger area are defined as long sides, and the other two sides are defined as short sides.

[0041] For the same square-shell battery cell, a second heat insulation sheet 23 is bonded and fixed to its two short sides. The area of ​​the second heat insulation sheet 23 is the same as the area of ​​the end side.

[0042] By setting a second heat insulation sheet 23, the heat generation effect between adjacent cells 21 along the second direction can be effectively eliminated. At the same time, it absorbs the expansion of cells 21 along the second direction during use, provides insulation, and protects against squeezing between cells 21, thus avoiding damage to cells 21 caused by expansion force.

[0043] Of its two long sides, the inner long side is bonded and fixed to the liquid cooling plate 22, and the outer long side is bonded and fixed to the first heat insulation sheet 3. The area of ​​the first heat insulation sheet 3 is the same as the area of ​​the long side.

[0044] By setting the first heat insulation sheet 3, the heat generation effect of adjacent battery cell units can be effectively eliminated. At the same time, it absorbs the expansion of the battery cell along the first direction during use, provides insulation, and protects against squeezing between battery cells, thus avoiding damage to the battery cell 21 caused by expansion force.

[0045] In this embodiment, the battery cell 21 is cooled by the liquid cooling plate 22 and insulated by the heat insulation sheet, which ensures the safe operation of the battery pack under extreme conditions.

[0046] In this embodiment, the battery cell assembly is provided with anti-expansion crossbeams on both sides along the first direction. The bottom of the anti-expansion crossbeams is fixedly connected to the bottom support plate of the housing 1 by welding or screw fastening. A heat-insulating flexible sheet is provided between the side of the battery cell assembly and the anti-expansion crossbeams. The battery cell assembly and the anti-expansion crossbeams are bonded and fixed to the heat-insulating flexible sheet.

[0047] The anti-expansion crossbeam can restrain the expansion of cell 21 and maintain the structural integrity of the battery pack.

[0048] Preferably, the heat-insulating flexible sheet is made of heat-insulating rubber sheet. The heat-insulating rubber material has good elasticity and insulation, which can both buffer pressure and prevent heat from being conducted to the metal anti-expansion beam.

[0049] The battery cell assembly is arranged between the anti-expansion crossbeams and bears the preload of the anti-expansion crossbeams as a whole. By setting heat-insulating rubber sheets, the anti-expansion crossbeams are prevented from directly squeezing the battery cell assembly.

[0050] The application of preload eliminates internal gaps in the battery cell assembly, increasing its rigidity, while the heat-insulating rubber sheet acts as a buffer to prevent damage caused by hard contact.

[0051] In this embodiment, since two battery cell assemblies are provided, three anti-expansion crossbeams are provided, namely the front anti-expansion crossbeam 11, the middle anti-expansion crossbeam 12, and the rear anti-expansion crossbeam 13.

[0052] Furthermore, along the first direction, the battery cell units 2 located at both ends of the battery cell assembly remove the battery cell groups located on the outer side. Therefore, the anti-expansion crossbeam cooperates with the liquid cooling plate 22 of the battery cell unit, that is, the heat insulation flexible sheet is set between the anti-expansion crossbeam and the liquid cooling plate 22 of the battery cell unit 2, and the liquid cooling plate 22, the anti-expansion crossbeam and the heat insulation flexible sheet are bonded and fixed.

[0053] like Figure 5 As shown, the flow channels of the liquid cooling plate 22 are connected to the cooling medium circulation pipeline at both ends. The cooling medium circulation pipeline includes cavity components fixed to both ends of the plate body 221 of the liquid cooling plate 22. The cavity component fixed to one side of the plate body 221 of the liquid cooling plate 22 serves as the inlet cavity component, and the cavity component fixed to the other side of the plate body 221 of the liquid cooling plate 22 serves as the outlet cavity component. One end of the flow channel communicates with the internal space of the inlet cavity component as the cooling medium inlet, and the other end of the flow channel communicates with the internal cavity of the outlet cavity component as the cooling medium outlet.

[0054] The cavity component is provided with a connector 222 on both the front and rear sides. The connector 222 adopts a circular tube structure and the internal space of the connector 222 is connected to the internal space of the cavity component.

[0055] The connector 222 adopts a round tube structure, which facilitates the connection between adjacent connectors 222 using standardized connectors.

[0056] In this embodiment, the cavity component of the liquid cooling plate 22 closest to the rear expansion beam 13 is not provided with a joint on the rear side or the joint on the rear side is sealed to prevent leakage of the cooling medium.

[0057] Along the first direction, in adjacent liquid cooling plates 22, the connector 222 on the rear side of the inlet cavity of one liquid cooling plate 22 is connected to the connector 222 on the front side of the inlet cavity of the other liquid cooling plate 22 via a connector.

[0058] The connector 222 on the rear side of the outlet cavity of one of the liquid cooling plates 22 is connected to the connector 222 on the front side of the outlet cavity of another liquid cooling plate 22 via a connector.

[0059] In this embodiment, since the connector 222 adopts a cylindrical structure, the connecting element adopts a connecting water jacket 24. One end of the connecting water jacket 24 is sealed around the outer periphery of one of the connectors 222, and the other end of the connecting water jacket 24 is sealed around the outer periphery of the other connector 222.

[0060] The sealing method between the water jacket 24 and the connector 222 can be achieved using existing technology, and will not be described in detail here.

[0061] In other embodiments, the two ends of the connecting water jacket 24 are provided with flange structures, and correspondingly, the outer end of the connector 222 is also provided with a flange structure, so that the connecting water jacket 24 can be connected to the connector 222 through the flange structure.

[0062] Those skilled in the art can set the connection form between the connector 222 and the connecting parts according to actual needs, which will not be described in detail here.

[0063] The front connector of the inlet cavity component of the liquid cooling plate 22 closest to the front anti-expansion crossbeam 11 serves as the cooling medium inlet 4 for the battery cell area, and is connected to one end of the first pipeline. The other end of the first pipeline is connected to the cooling medium inlet 15 provided in the housing 1.

[0064] The front connector of the outlet cavity component of the liquid cooling plate 22 closest to the front anti-expansion crossbeam 11 serves as the cooling cut-off outlet 5 for the battery cell area, and is connected to one end of the second pipeline. The other end of the second pipeline is connected to the cooling medium outlet 16 provided in the housing 1.

[0065] The cooling medium can enter the first pipeline through the cooling medium inlet 15. After passing through the first pipeline, it flows through the inlet cavity of multiple liquid cooling plates 22 in sequence, and then flows into the flow channel of the liquid cooling plate 22 through the inlet cavity. The cooling medium flows in the flow channel and exchanges heat with the battery cell 21. After cooling the battery cell 21, it flows into the outlet cavity and then flows through the second pipeline to the cooling medium outlet 16 for discharge.

[0066] Preferably, both the first and second pipelines are made of flexible hoses. The flexibility of the hoses compensates for manufacturing and assembly errors, reduces installation difficulty, and facilitates the connection of the first pipeline to the cooling medium inlet 15 and the connector 222, and the connection of the second pipeline to the cooling medium outlet 16 and the connector 222.

[0067] Furthermore, a notch is provided on the front anti-expansion beam 11 to allow the connector 222 on the front side of the inlet cavity and outlet cavity of the liquid cooler 22 to pass through, thus forming a space for the connector 222 to pass through the front anti-expansion beam 11.

[0068] In this embodiment, as Figure 4As shown, for a square-shell cell, except for the long side that is glued to the liquid cooling plate 22, the other three sides are covered by heat insulation sheets to form a "C"-shaped heat insulation ring to avoid mutual thermal influence. In addition, due to the presence of the first heat insulation sheet 3 and the second heat insulation sheet 23, each cell unit 2 does not need to be provided with end plates on both sides. Each cell unit 2 can be placed tightly side by side in the housing 1 of the battery pack. The front anti-expansion crossbeam 11, the middle anti-expansion crossbeam 12, and the rear anti-expansion crossbeam 13 are fixed by the bottom support plate 14 of the housing 1 as end plates of the overall cell cooling area, forming an integral CTP-like structure, which improves the strength and energy density of the battery pack.

[0069] In the power battery pack structure of this embodiment, multiple cell units 2 are arranged along a first direction. After a first heat insulation sheet 3 is set between adjacent cell units 2, the multiple cell units 2 and the first heat insulation sheet 3 are bonded and fixed together. The resulting cell assembly is then fixed inside the housing 1. Compared with the traditional method of setting end plates around multiple cell units to form a cell module, and then fixing each cell module independently inside the housing, the multiple cell units 2 are pre-bonded and extruded and fixed. When installed in the housing 1, there is no need to set gaps or beams between adjacent cell units 2, which increases the utilization rate of the space inside the housing 1 and increases the overall energy density. At the same time, the multiple cell units form an integral structure, which improves the overall strength and rigidity of the battery pack structure.

[0070] Example 2 This embodiment provides a method for assembling the power battery pack structure described in Embodiment 1, including the following steps: Step 1: Prepare the battery cell assembly.

[0071] The fabrication of the battery cell assembly includes the following specific steps: Step 1.1: Prepare the battery cell unit.

[0072] Step 1.2 Assemble the battery cell units to form a battery cell assembly.

[0073] The method for manufacturing the battery cell unit is as follows: First, multiple sets of battery cell assemblies are manufactured, and then the battery cell assemblies are assembled with the liquid cooling plate 22 to complete the manufacturing of the battery cell unit 2. The specific steps are as follows: Step 1.1.1: Arrange and bond multiple battery cells 21 along the second direction, and bond and fix the second heat insulation sheet 23 between adjacent battery cells 21 to complete the preparation of the battery cell assembly. Specifically: Select the first square-shell cell in the cell assembly, and bond the second heat insulation sheet 23 to its two end sides. Then, bond and fix one short side of the second square-shell cell to the second heat insulation sheet 23 at one end of the first square-shell cell. Use the same method to bond and fix the remaining second heat insulation sheets 23 and square-shell cells along the second direction in sequence to complete the preparation of the cell assembly.

[0074] During this step, adhesive needs to be applied evenly to the side of the square-shell battery cell, and then the second heat insulation sheet 23 is bonded and fixed to the square-shell battery cell.

[0075] Step 1.1.2: After uniformly applying adhesive to the long side of each square-shell cell in the cell assembly, bond one side of the liquid cooling plate 22 to a cell assembly and the other side to another cell assembly, thus completing the fabrication of cell unit 2.

[0076] When manufacturing the cell unit 2, two cell units 2 are reserved and the cell assembly is bonded to one side of the liquid cooling plate 22, serving as the cell units 2 at the two ends of the cell assembly.

[0077] The specific method for assembling the battery cell unit 2 is as follows: multiple battery cell units 2 are arranged and bonded along the first direction, and the first heat insulation sheet 3 is bonded and fixed between adjacent battery cell units to complete the preparation of the battery cell assembly.

[0078] Specifically: After applying adhesive to the long side of the square-shell cell of the first cell unit 2 at the end and bonding the first heat insulation sheet 3, one long side of the cell of the second cell unit is bonded and fixed to the first heat insulation sheet 3. Then, adhesive is evenly applied to the other long side of the cell 21 of the second cell unit 2 and the first heat insulation sheet 3 is bonded. Using the same method, multiple first heat insulation sheets 3 and cell units 2 are bonded and fixed in sequence, thus completing the fabrication of the entire cell assembly.

[0079] Step 2: Install the battery cell assembly inside the housing.

[0080] Specifically, heat-insulating rubber sheets are bonded to both sides of the first battery cell assembly. Then, a clamp is used to apply pressure to the first battery cell assembly, which is then placed between the pre-installed front anti-expansion crossbeam 11 and the middle anti-expansion crossbeam 12 on the bottom support plate 14 of the housing 1. The bottom surface of the first battery cell assembly is then bonded and fixed to the bottom support plate 14 of the housing 1 using structural adhesive. After the clamp is removed, the first battery cell assembly springs back, and the heat-insulating rubber sheets on both sides contact and bond with the front anti-expansion crossbeam 11 and the middle anti-expansion crossbeam 12, respectively.

[0081] Heat-insulating rubber sheets are bonded to both sides of the second battery cell assembly. Then, clamping force is applied to the second battery cell assembly using a clamp. The second battery cell assembly is then placed between the middle anti-expansion crossbeam 12 and the rear anti-expansion crossbeam 13 pre-set on the bottom support plate 14 of the housing 1. The bottom surface of the second battery cell assembly is bonded and fixed to the bottom support plate 14 of the housing 1 using structural adhesive. After the clamp is removed, the second battery cell assembly springs back, and the heat-insulating rubber sheets on both sides of it come into contact with and are bonded and fixed to the middle anti-expansion crossbeam 12 and the rear anti-expansion crossbeam 13, respectively.

[0082] The fixture can be made using existing equipment, and its specific structure will not be described in detail here.

[0083] Step 3: Install the cooling medium circulation pipeline.

[0084] The connectors 222 of the inlet cavity components of adjacent liquid cooling plates 22 are connected sequentially through the connecting water jacket 24, and the connectors 222 of the outlet cavity components are connected sequentially through the connecting water jacket 24.

[0085] The connector 222 of the inlet cavity component of the liquid cooling plate 22 located at the front is connected to the cooling medium inlet 15 on the housing 1 through the first pipeline, and the connector 222 of the outlet cavity component of the liquid cooling plate 22 located at the front is connected to the cooling medium outlet 16 on the housing 1 through the second pipeline.

[0086] The assembly of the remaining battery pack structures can be carried out using existing technologies, and further technical details will not be described in detail here.

[0087] Example 3 This embodiment provides a power battery pack structure, including a housing, inside which a cell assembly is disposed. The cell assembly includes multiple cell units 2 arranged sequentially along a first direction, with a first heat insulation sheet 3 between adjacent cell units 2. The multiple cell units 2 and the first heat insulation sheet 3 are bonded and fixed together. The cell unit 2 includes a liquid cooling plate 22, and cell groups are bonded and fixed on both sides of the liquid cooling plate 22. The cell group includes multiple square-shell cells arranged sequentially along a second direction, with a second heat insulation sheet 23 between adjacent square-shell cells. The multiple square-shell cells and the second heat insulation sheet 23 are bonded and fixed together to form a cell group. Compared with embodiment 1, only one cell assembly is disposed inside the housing 1. Correspondingly, a front anti-expansion crossbeam 11 and a rear anti-expansion crossbeam 13 are disposed on both sides of the cell assembly, eliminating the need for a middle anti-expansion crossbeam 12.

[0088] The rest of the structure in this embodiment is exactly the same as in Embodiment 1, and will not be described in further detail here.

[0089] In this embodiment of the power battery pack structure, after the cell assembly is fabricated, heat-insulating rubber sheets are bonded to both sides of the cell assembly. Pressure is applied to the cell assembly using a clamp, causing it to slightly contract. The amount of contraction is determined based on actual operating conditions and will not be described in detail here. The cell assembly is then placed between the pre-set front anti-expansion crossbeam 11 and rear anti-expansion crossbeam 13 on the bottom support plate 14 of the housing 1. The cell assembly springs back, and the heat-insulating rubber sheets on both sides contact and bond to the front anti-expansion crossbeam 11 and rear anti-expansion crossbeam 13, respectively. The fabrication method of the cell assembly is exactly the same as in Embodiment 2 and will not be repeated here. The assembly method of the cooling medium circulation pipeline is exactly the same as in Embodiment 2 and will not be repeated here.

[0090] Example 4 This embodiment provides a new energy vehicle, which is equipped with the power battery pack structure described in Embodiment 1 or Embodiment 3. The rest of the vehicle structure can be constructed using existing technology, and will not be described in further detail here.

[0091] New energy vehicles can be pure electric passenger vehicles, pure electric commercial vehicles, or plug-in hybrid electric vehicles, etc. Those skilled in the art can choose according to actual needs. By applying the power battery pack structure of Embodiment 1 or Embodiment 3, new energy vehicles can achieve longer driving range, higher safety and better space utilization.

[0092] When the battery pack structure of Example 1 or Example 3 is applied to new energy vehicles, the high energy density characteristics of the battery pack structure of Example 1 or Example 3 can significantly improve the driving range of the vehicle on a single charge.

[0093] In terms of safety, thanks to the multi-layered heat insulation and the efficient liquid cooling system, the battery pack structure of Embodiment 1 or Embodiment 3 can effectively suppress the occurrence and spread of thermal runaway. Even in extreme collision accidents, the anti-expansion beam and shell structure can provide strong protection for the cell 21, preventing the cell 21 from being squeezed and deformed, thus preventing safety accidents. At the same time, the buffering effect of the flexible heat insulation and the liquid cooling plate 22 can also absorb collision energy to a certain extent, protecting the integrity of the internal battery structure.

[0094] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A power battery pack structure, comprising a housing, wherein a battery cell assembly is disposed within the housing, characterized in that, The battery cell assembly includes multiple battery cell units arranged along a first direction, with a flexible and heat-insulating first heat insulation sheet bonded between adjacent battery cell units. Each battery cell unit includes multiple battery cell groups arranged along the first direction, with a liquid cooling plate bonded between adjacent battery cell groups. Each battery cell group includes multiple battery cells arranged along a second direction, with a flexible and heat-insulating second heat insulation sheet bonded between adjacent battery cells. The second direction is perpendicular to the first direction. A flow channel is provided on the inner side of the liquid cooling plate, and both ends of the flow channel are connected to a cooling medium circulation pipeline.

2. The power battery pack structure as described in claim 1, characterized in that, Along the first direction, anti-expansion crossbeams are provided on both sides of the battery cell assembly. The anti-expansion crossbeams are fixedly connected to the housing, and a heat-insulating flexible sheet is provided between the anti-expansion crossbeams and the battery cell assembly.

3. The power battery pack structure as described in claim 2, characterized in that, The heat-insulating flexible sheet is made of heat-insulating rubber sheet.

4. The power battery pack structure as described in claim 1, characterized in that, The first and second heat insulation sheets are made of MMP-type foam pads, silicone foam pads, or aerogel pads.

5. The power battery pack structure as described in claim 1, characterized in that, The cooling medium circulation pipeline includes cavity components disposed on both sides of the liquid cooling plate. The cavity components are connected to the flow channel. The cavity components are provided with joints on the front and rear sides. The joints of the cavity components on the same side of adjacent liquid cooling plates are connected by connectors. The cavity component on one side of the liquid cooling plate at one end is connected to the cooling medium inlet pipe disposed on the shell through a pipeline, and the cavity component on the other side is connected to the cooling medium outlet pipe disposed on the shell through a pipeline.

6. The power battery pack structure as described in claim 5, characterized in that, The connector is a connector tube, which is connected to the internal space of the cavity component. Correspondingly, the connecting component is a sleeve. In two adjacent connector tubes, one end of the sleeve is sealed around the outer circumference of one connector tube, and the other end is sealed around the outer circumference of the other connector tube.

7. A power battery pack structure as described in claim 1, characterized in that, The cross-section of the flow channel is S-shaped or oblique rhomboid.

8. A power battery pack structure as described in claim 1, characterized in that, The bottom surface of the battery cell assembly is bonded and fixed to the bottom surface of the casing with structural adhesive.

9. A method for assembling a power battery pack structure according to any one of claims 1-8, characterized in that, Includes the following steps: Multiple battery cells are arranged and bonded together along the second direction, and a second heat insulation sheet is bonded between adjacent battery cells to complete the preparation of the battery cell assembly. The prepared battery cell assembly is bonded to both sides of the liquid cooling plate to complete the preparation of the battery cell unit; Multiple battery cell units are arranged and bonded together along a first direction, and a first heat insulation sheet is bonded between adjacent battery cell units to complete the preparation of the battery cell assembly. The battery cell assembly is fixed inside the housing, and a cooling medium circulation pipeline connected to the liquid cooling plate channel is assembled.

10. A car, characterized in that, The power battery pack structure according to any one of claims 1-8 is provided.

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