Battery packs and electrical equipment

Abstract

This invention relates to the field of battery technology and discloses a battery pack and related electrical equipment, comprising: a housing, the installation space of which is enclosed by a pair of longitudinal side beams and a pair of transverse side beams; a cold plate connected to the bottom of the housing along the Z direction; a plurality of battery cell modules, arranged in rows along the X and Y directions within the installation space, wherein the gap H1 between the battery cell modules and adjacent longitudinal side beams satisfies 30mm≤H1≤50mm; the battery cell modules are bonded to the cold plate with thermally conductive structural adhesive, and the bonding area between the battery cell modules and the cold plate is greater than or equal to 90%; and a first partition plate bonded between every two adjacent battery cell modules arranged along the Y direction, with a bonding area greater than or equal to 80%. This invention effectively improves the overall structural rigidity of the battery pack, resulting in a higher inherent mode of the battery pack, thereby avoiding the overlap of the inherent mode of the battery pack with the resonant frequency of the vehicle and ensuring the overall safety and reliability of the battery pack.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a battery pack and electrical equipment. Background Technology

[0002] Battery packs are generally composed of multiple cells. Cells such as lithium-ion cells are widely used in various fields such as transportation power supply, power storage power supply, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high operating voltage, strong charge retention capability and long cycle life.

[0003] When battery packs are used in automobiles, the vehicle will generate continuous vibrations while driving. However, traditional battery packs have poor overall stiffness, and the inherent modes of the battery pack coincide with the resonant frequency of the vehicle, which leads to resonance amplification, resulting in battery pack structural fatigue, cracking, and even cell failure and thermal runaway, seriously threatening the safety of the entire vehicle. Summary of the Invention

[0004] In view of this, the present invention provides a battery pack and electrical equipment to solve the problem that the poor overall stiffness of the battery pack causes the inherent modes of the battery pack to coincide with the resonant frequency of the vehicle.

[0005] In a first aspect, the present invention provides a battery pack, comprising:

[0006] The box body has a pair of longitudinal side beams arranged opposite each other along the Y direction and a pair of transverse side beams arranged opposite each other along the X direction, and the pair of longitudinal side beams and the pair of transverse side beams are connected in sequence to form an installation space;

[0007] Cold plate, connected to the bottom of the housing along the Z direction;

[0008] Several battery cell modules are arranged in rows along the X and Y directions within the installation space. The gap H1 between each battery cell module and the adjacent longitudinal side beam satisfies 30mm ≤ H1 ≤ 50mm. The battery cell modules are bonded to the cold plate, and the bonding area between the battery cell module and the cold plate is greater than or equal to 90%.

[0009] The first partition is bonded between every two adjacent battery cell modules arranged along the Y direction, and the bonding area is greater than or equal to 80%.

[0010] Beneficial effects: By ensuring that the bonding area between the cell module and the cold plate is greater than or equal to 90%, the air gap between the cell module and the cold plate can be effectively eliminated, thereby ensuring the thermal conductivity between the cell module and the cold plate. Furthermore, a properly designed bonding area between the cell module and the cold plate allows for full contact, effectively improving the overall structural rigidity of the battery pack and resulting in higher inherent modes. This prevents the inherent modes of the battery pack from coinciding with the resonant frequency of the vehicle, ensuring the overall safety and reliability of the battery pack.

[0011] Further optimizing the gap between the battery cell module and the longitudinal side beam ensures that even during vehicle operation, when the battery cell module experiences minor displacement due to vibration, this gap prevents hard contact between the battery cell module and the longitudinal side beam, thus preventing wear or stress concentration in either the battery cell module or the longitudinal side beam. It also provides tolerance for errors in the battery cell module assembly process, reducing the difficulty of battery cell module installation. The gap between the battery cell module and the adjacent longitudinal side beam prevents the battery cell module from being rigidly mounted within the battery pack. This allows the integrated structure formed after the battery cell module is bonded to the cold plate to effectively disperse the vibration energy of the entire vehicle, preventing localized resonance between the battery pack and the vehicle, and improving the overall modal characteristics of the battery pack.

[0012] The first partition connects two adjacent cell modules into a single unit, preventing independent swaying of individual cell modules during vibration and improving the overall structural integrity and rigidity of the battery pack. By rationally setting the bonding area between two adjacent cell modules, a firm connection is formed between the first partition and the cell modules, further eliminating relative displacement between them. This makes the entire cell module array a rigid whole, significantly increasing the natural frequency of the battery pack. This effectively enhances the battery pack's modal characteristics, ensuring that the modal characteristics are greater than the vibration frequency range of the vehicle during movement. This prevents resonance between the battery pack and the vehicle, improving the battery pack's safety performance.

[0013] In one alternative embodiment, each of the battery cell modules includes two rows of battery cell groups arranged along the Y direction, and each battery cell group includes a plurality of battery cells arranged along the X direction;

[0014] The second partition is bonded between two adjacent cell groups in each cell module, and the bonding area is greater than or equal to 80%.

[0015] Beneficial effects: Connecting adjacent cell groups into a single unit via the second separator prevents independent swaying of individual cell groups during vibration, thus improving the overall structural integrity and rigidity of the battery pack. By rationally setting the bonding area between the cell group and the second separator, the cell array within the entire cell module forms a unified rigid structure, further enhancing the natural frequency of the battery pack and effectively improving its modal characteristics, thereby further enhancing its safety performance.

[0016] In one alternative embodiment, along the Z direction, the second partition has a first end and a second end, both the first end and the second end are provided with blocking portions, and the blocking portions are disposed on both sides of the second partition along the Y direction.

[0017] Beneficial Effects: By placing the blocking portions at the first and second ends of the second separator, located on opposite sides in the Y direction and extending along the X direction of the second separator, the blocking portions can cover paths where adhesive easily overflows. The blocking portions are baffles extending from the first and second ends of the second separator along the Y direction to both sides, and abutting against the sidewalls of the battery cell along the Y direction. When adhesive is applied to the bonding surface between the second separator and the battery cell, it flows along both sides in the Y direction and both ends in the Z direction under pressure. When the adhesive encounters the blocking portions, it is intercepted, preventing it from overflowing onto the non-bonding surface of the battery cell or other areas of the battery cell module; simultaneously, the intercepted adhesive flows back into the bonding surface, which actually increases the actual bonding area between the second separator and the battery cell, thereby improving the overall mode of the battery pack.

[0018] In one optional embodiment, the length L of the battery cell satisfies 200mm≤L≤500mm, and the width W1 of the battery cell satisfies 20mm≤W1≤60mm.

[0019] The thickness T of both the first partition and the second partition satisfies 6%W1≤T≤8%W1;

[0020] The height of the first partition is H2, and the height of the battery cell is H3, satisfying 1 / 3≤H2 / H3≤1 / 2;

[0021] The height of the second partition is H4, which satisfies H4 / H3≥1.1.

[0022] Beneficial effects: By rationally setting the thickness of the first and second separators, the strength of the separators themselves is ensured, and the space utilization rate of the cells within the battery pack is guaranteed. Further rationally setting the ratio between the height of the first separator and the height of the cell ensures sufficient bonding area between the first separator and the cell module while providing enough space for the thermally conductive adhesive to overflow between adjacent cell modules, thus improving the connection stability between connected cell modules. Further rationally setting the height ratio between the second separator and the cell ensures that the height of the second separator covers the cell, facilitating bonding between the second separator and the cell assembly. This also eliminates relative displacement space between cell assemblies, integrating all cells within the cell module into a single rigid structure, which helps improve the overall modal characteristics of the battery pack and prevents resonance between the battery pack and the vehicle.

[0023] In one alternative embodiment, a heat insulation element is further included, which is located between two adjacent cells and has a thickness of 1% W1 - 3% W1.

[0024] Beneficial effects: By reasonably setting the thickness of the heat insulation component, the heat insulation component can effectively absorb the small displacement of the battery cell expansion and provide sufficient elastic buffer space; moreover, the heat insulation component will not encroach on the battery cell arrangement space, which can maximize the energy density of the battery pack; at the same time, the heat insulation component can also assist in thermal isolation, effectively blocking the heat conduction between battery cells and avoiding the failure of the heat insulation component due to compression during expansion.

[0025] In one optional embodiment, a first overflow portion is provided between two adjacent battery cell modules, the height of the first overflow portion is H5, and the height of the longitudinal side beam is H6, satisfying H5 / H6≥1 / 4.

[0026] Beneficial effects: By reasonably setting the height ratio of the first overflow section to the longitudinal side beam, it can be ensured that the first overflow section has sufficient height, thereby providing sufficient buffer space for cell expansion throughout the entire cycle. This avoids the expansion force being directly applied to the cell module or housing, thus preventing cell displacement or cell housing deformation due to compression. When the expansion force is dispersed, the internal separator, electrolyte, and electrode of the cell are not compressed, which can reduce failure modes such as lithium plating and lithium dendrite growth, directly improving the cell's EOL cycle life, and thus improving the cycle life of the battery pack.

[0027] In one optional embodiment, the box body is provided with a first crossbeam along the Y direction, the two ends of the first crossbeam are respectively connected to the longitudinal side beam, and along the X direction, the width of the first crossbeam is W2, which satisfies 20mm≤W2≤30mm;

[0028] There is a second overflow section between the longitudinal side beam and the cell module. The height of the second overflow section is H7, and the height of the first crossbeam is H8, satisfying H7 / H8≥1 / 2.

[0029] Beneficial effects: By reasonably setting the height ratio of the second overflow section to the first crossbeam, the second overflow section can be ensured to have sufficient height, thereby providing sufficient buffer space for cell expansion throughout the entire cycle. This avoids the expansion force being directly applied to the cell module or housing, thus preventing cell displacement or cell housing deformation due to compression. When the expansion force is dispersed, the internal separator, electrolyte, and electrode of the cell are not compressed, which can reduce failure modes such as lithium plating and lithium dendrite growth, directly improving the cell's EOL cycle life and thus improving the cycle life of the battery pack.

[0030] In one alternative embodiment, along the X direction, the housing has a first mounting area located on one side of the first crossbeam and a second mounting area located on the other side of the first crossbeam, the ratio of the area of ​​the first mounting area to the area of ​​the second mounting area being 1.1-1.3.

[0031] Beneficial effects: By reasonably setting the ratio of the area of ​​the first installation area to the area of ​​the second installation area, the cell arrangement space in the first installation area is increased, so that the center of gravity of the battery pack always falls within the center of gravity adaptation range of the vehicle chassis, thereby meeting the requirements of vehicle driving stability.

[0032] In one optional embodiment, the cold plate is provided with a plurality of limiting strips arranged at intervals along the Y direction, the limiting strips extending along the X direction and respectively disposed in the first installation area and the second installation area.

[0033] Beneficial effects: By applying thermally conductive structural adhesive between two adjacent limiting strips, the amount of thermally conductive structural adhesive between each pair of limiting strips is consistent, thereby ensuring the uniformity of the bonding between the battery cell and the cold plate. This allows the heat generated by the battery cell to be transferred evenly and stably to the thermally conductive structural adhesive, and further conducted quickly to the cold plate through the thermally conductive structural adhesive, thus facilitating the heat dissipation of the battery cell.

[0034] Secondly, the present invention also provides an electrical device, comprising: a battery pack as described above.

[0035] Beneficial effects: Since the electrical equipment includes the aforementioned battery pack, it has the same effects as the battery pack, which will not be elaborated here. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the exploded structure of a battery pack according to an embodiment of the present invention;

[0038] Figure 2 This is a top view of a battery pack according to an embodiment of the present invention;

[0039] Figure 3 for Figure 2 Cross-sectional view along the middle AA;

[0040] Figure 4 for Figure 3 A magnified view of part B in the diagram;

[0041] Figure 5 for Figure 3 A magnified view of part of C;

[0042] Figure 6 This is a schematic diagram of the structure of the casing and cold plate in a battery pack according to an embodiment of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 100. Housing; 110. Longitudinal side beam; 120. Transverse side beam; 130. First partition; 140. First crossbeam; 150. Second crossbeam; 160. Third crossbeam; 170. First installation area; 180. Second installation area; 200. Battery cell module; 210. Battery cell; 220. Second partition; 221. Blocking part; 300. Thermally conductive structural adhesive; 310. First overflow adhesive part; 320. Second overflow adhesive part; 400. Cold plate; 410. Limiting strip; 500. Bottom guard plate. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] The following is combined with Figures 1 to 6 The following describes embodiments of the present invention.

[0047] According to an embodiment of the present invention, in one aspect, such as Figures 1 to 4 As shown, a battery pack is provided, including: a housing 100 having a pair of longitudinal side beams 110 arranged opposite each other along the Y direction and a pair of transverse side beams 120 arranged opposite each other along the X direction, the pair of longitudinal side beams 110 and the pair of transverse side beams 120 being connected in sequence to form an installation space; a cold plate 400 connected to the bottom of the housing 100 along the Z direction; a plurality of battery cell modules 200 arranged in rows along the X and Y directions within the installation space, the gap H1 between the battery cell module 200 and the adjacent longitudinal side beam 110 satisfying 30mm≤H1≤50mm; the battery cell module 200 is bonded to the cold plate 400, and the bonding area between the battery cell module 200 and the cold plate 400 is greater than or equal to 90%; a first partition 130 is bonded between every two adjacent battery cell modules 200 arranged along the Y direction, and the bonding area is greater than or equal to 80%.

[0048] In this embodiment, the X direction is the length direction of the battery pack, the Y direction is the width direction of the battery pack, and the Z direction is the height direction of the battery pack. The housing 100 has a pair of longitudinal side beams 110 arranged opposite each other along the Y direction and a pair of transverse side beams 120 arranged opposite each other along the X direction. The pair of longitudinal side beams 110 and the pair of transverse side beams 120 are connected sequentially to enclose an installation space for accommodating the cell module 200. Along the Z direction, the upper and lower ends of the housing 100 have interconnected openings, allowing the cell module 200 to be installed into the housing 100 through the opening at the top. A cold plate 400 is connected to the bottom of the housing 100 along the Z direction, allowing the cold plate 400 to seal the opening at the bottom of the housing 100. The cold plate 400 has cooling channels inside, through which coolant flows to quickly remove the heat from the battery module 200 during operation, thus preventing thermal runaway. At the same time, the cold plate 400 also serves as the load-bearing support surface for the battery module 200, providing a stable heat conduction and mounting foundation for the battery cell 210.

[0049] Several battery cell modules 200 are arranged in rows along the X and Y directions within the installation space, ensuring a regular arrangement of the cell modules 200 within the housing 100 and maximizing the space utilization of the battery pack. Multiple cell modules 200 can be connected in series, parallel, or in a mixed configuration via a busbar to form a battery pack. The bottom of each cell module 200 is bonded to the cold plate 400 using thermally conductive structural adhesive 300 to form a stable structural connection. The heat generated by the cell module 200 can also be transferred to the thermally conductive structural adhesive 300, which then efficiently conducts the heat to the cold plate 400, ensuring uniform operating temperature of the cell module 200 and preventing localized overheating that could lead to thermal runaway. The bonding area between the cell module 200 and the cold plate 400 can be any value from 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, and 100%, or any value between any two of these.

[0050] By ensuring that the bonding area between the cell module 200 and the cold plate 400 is greater than or equal to 90%, the air gap between them can be effectively eliminated, thus guaranteeing the thermal conductivity between them. Furthermore, a properly designed bonding area between the cell module 200 and the cold plate 400 allows for full contact, effectively improving the overall structural rigidity of the battery pack and resulting in higher inherent modes. This prevents the inherent modes of the battery pack from coinciding with the resonant frequency of the vehicle, ensuring the overall safety and reliability of the battery pack.

[0051] The gap H1 between the cell module 200 and the adjacent longitudinal side beam 110 can be any value of 30mm, 35mm, 40mm, 45mm, or 50mm, or any value between two of these. By reasonably setting the gap between the cell module 200 and the longitudinal side beam 110, even if the cell module 200 undergoes slight displacement due to vibration during vehicle operation, this gap can prevent hard contact between the cell module 200 and the longitudinal side beam 110, thus preventing wear or stress concentration in either the cell module 200 or the longitudinal side beam 110. It also provides tolerance space for the assembly process of the cell module 200, reducing the difficulty of its installation. The gap between the cell module 200 and the adjacent longitudinal side beam 110 prevents the cell module 200 from being rigidly mounted within the housing 100, allowing the overall structure formed after the cell module 200 is bonded to the cold plate 400 to effectively disperse the vibration energy of the entire vehicle, avoiding local resonance between the battery pack and the vehicle, and improving the overall modal characteristics of the battery pack.

[0052] Along the Y-direction, a first partition 130 is bonded between every two adjacent battery cell modules 200. The bonding area can be any value or any combination of 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, and 90%. The first partition 130 connects adjacent battery cell modules 200 into a single unit, preventing independent swaying of individual battery cell modules 200 during vibration, thus improving the overall integrity and rigidity of the battery pack structure. By rationally setting the bonding area between adjacent battery cell modules 200, a firm connection is formed between the first partition 130 and the battery cell modules 200, further eliminating relative displacement between the battery cell modules 200. This makes the entire array of battery cell modules 200 a rigid whole, significantly increasing the natural frequency of the battery pack. This effectively enhances the modal characteristics of the battery pack, ensuring that the modal characteristics are greater than the vibration frequency range during vehicle movement, preventing resonance between the battery pack and the vehicle, and improving the safety performance of the battery pack.

[0053] In one embodiment, each cell module 200 includes two rows of cell groups arranged along the Y direction, and each cell group includes a plurality of cells 210 arranged along the X direction; a second partition 220 is bonded between two adjacent cell groups in each cell module 200, and the bonding area is greater than or equal to 80%.

[0054] In this embodiment, each cell module 200 includes two rows of cell groups arranged along the Y direction, and each cell group includes several cells 210 arranged along the X direction. Along the X direction, pressure plates are provided at both ends of the cell module 200, and along the Y direction, the pressure plates at least partially cover the two rows of cell groups. When the cell module 200 needs to be installed into the housing 100, the pressure plates at both ends of the cell module 200 are clamped by a clamping device, allowing both rows of cell groups to be simultaneously placed into the housing 100. Unlike traditional cell modules, this cell module 200 does not require end plates and side plates on the outer periphery of the cells 210, thereby increasing the usable space within the housing 100 of the battery pack, which is beneficial for improving the overall energy density of the battery pack. Furthermore, it reduces the assembly steps of the cell module 200, lowering the manufacturing cost of the battery pack.

[0055] In each cell module 200, a second separator 220 is bonded between two adjacent cell groups. Double-sided adhesive is applied to the side of the second separator 220 or to the side of the cell 210 closest to the second separator 220, thus bonding the cell 210 to the second separator 220. This allows the two cell groups to fit together with the second separator 220, forming a single unit, i.e., the cell module 200. The bonding area between the cell group and the second separator 220 can be any value from 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, and 90%, or any combination of any two values. If the bonding area between the cell group and the second separator 220 is too small, such as less than 80%, the bonding may be weak, leading to relative displacement between the cell 210 and the second separator 220, thereby compromising the integrity of the cell 210 array and reducing the overall mode of the battery pack. Both the first partition 130 and the second partition 220 can be epoxy boards.

[0056] The second separator 220 connects two adjacent cell groups into a whole, preventing independent swaying of individual cell groups during vibration, which helps improve the overall integrity and rigidity of the battery pack structure. By reasonably setting the bonding area between the cell group and the second separator 220, the array of cells 210 within the entire cell module 200 forms a rigid whole structure, which can further increase the natural frequency of the battery pack, effectively improve the mode of the battery pack, and further enhance the safety performance of the battery pack.

[0057] Furthermore, the battery cell 210 is formed by assembling a battery cell housing, a battery cell cover plate, and an electrode assembly. The battery cell housing has a receiving cavity and an opening communicating with the receiving cavity, through which the electrode assembly is installed into the receiving cavity. The battery cell cover plate is installed on the opening of the battery cell housing, serving to fix and seal, thereby enclosing the internal components such as the electrode assembly within the battery cell housing to prevent the entry of external impurities and moisture, while also preventing leakage of the internal electrolyte, providing a stable working environment for the battery cell 210. The electrode posts are set in the mounting holes on the battery cell cover plate and are electrically connected to the tabs on the electrode assembly. During the charging or use of the battery cell 210, the heat generated by the electrode assembly can be transferred to the bottom of the battery cell 210, and further transferred to the cold plate 400, whereby the cold plate 400 dissipates the heat, thereby cooling the battery cell 210 and reducing its temperature rise.

[0058] When the second separator 220 is bonded between two adjacent cell groups along the Y direction, the adhesive applied during the gluing process will overflow to both sides along the Y direction due to pressure. If the adhesive overflows onto the non-bonding surface of the cell 210, it will contaminate the surface of the cell 210 and may even seep into components such as the cell terminals and sealing rings, leading to short circuits or sealing failures in the cell 210. If the adhesive overflows into other areas inside the cell module 200, it may stick to other components, affecting subsequent assembly, and may even harden into hard spots, damaging the flexible buffer of the cell 210 array and indirectly reducing the overall mode of the battery pack.

[0059] In one embodiment, along the Z direction, the second partition 220 has a first end and a second end, both the first end and the second end are provided with a blocking portion 221, and the blocking portion 221 is disposed on both sides of the second partition 220 along the Y direction.

[0060] In this embodiment, along the Z-direction, the second partition 220 has a first end and a second end located at its upper and lower ends. The first end and the second end are the two vertical endpoints of the second partition 220. A blocking portion 221 is disposed on the second partition 220, with the first end and the second end located on opposite sides in the Y-direction, and extending along the X-direction of the second partition 220, so that the blocking portion 221 can cover the path where glue easily overflows. The blocking portion 221 is a baffle extending from the first end and the second end of the second partition 220 to both sides along the Y-direction, and the blocking portion 221 abuts against the side wall of the battery cell 210 along the Y-direction.

[0061] When the adhesive is applied to the bonding surface between the second separator 220 and the cell 210, it will flow along both sides in the Y direction and both ends in the Z direction under pressure. When the adhesive encounters the blocking part 221, it will be intercepted by the blocking part 221, preventing the adhesive from overflowing onto the non-bonding surface of the cell 210 or other areas of the cell module 200; at the same time, the intercepted adhesive will flow back into the bonding surface, which can increase the actual bonding area between the second separator 220 and the cell 210, thereby helping to improve the overall mode of the battery pack.

[0062] In one embodiment, the length L of the battery cell 210 satisfies 200mm≤L≤500mm, and the width W1 of the battery cell 210 satisfies 20mm≤W1≤60mm; the thickness T of the first separator 130 and the second separator 220 both satisfy 6%W1≤T≤8%W1; the height of the first separator 130 is H2, and the height of the battery cell 210 is H3, satisfying 1 / 3≤H2 / H3≤1 / 2; the height of the second separator 220 is H4, satisfying H4 / H3≥1.1.

[0063] In this embodiment, the length L of the battery cell 210 can be any value or any two values ​​between 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, and 500mm; the width W1 of the battery cell 210 can be any value or any two values ​​between 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, and 60mm.

[0064] The thickness T of both the first separator 130 and the second separator 220 satisfies 6%W1-8%W1, i.e., 1.2mm-4.8mm. Therefore, the thickness T of the first separator 130 and the second separator 220 can be any value or any value between any two of the following: 1.2mm, 1.5mm, 1.7mm, 2.0mm, 2.2mm, 2.5mm, 2.7mm, 3.0mm, 3.2mm, 3.5mm, 3.7mm, 4.0mm, 4.2mm, 4.5mm, and 4.8mm. If the thickness of the separator is too small, such as less than 1.2mm, the separator may be prone to deformation and have insufficient rigidity after bonding, leading to loosening of the cell 210 array and directly reducing the battery pack mode. If the thickness of the separator is too large, such as greater than 4.8mm, the separator will encroach on the effective space of the cell 210, thereby reducing the energy density of the battery pack. By reasonably setting the thickness of the first separator 130 and the second separator 220, the strength of the separator itself is ensured, and the space utilization rate of the battery cell 210 inside the battery pack is also ensured.

[0065] Along the Z-direction, the height of the first partition 130 is H2, and the height of the battery cell 210 is H3. H2 / H3 can be any value from 0.34, 0.38, 0.42, 0.46, and 0.5, or any value between any two. By reasonably setting the ratio between the height of the first partition 130 and the height of the battery cell 210, while ensuring the bonding area between the first partition 130 and the battery cell module 200, sufficient overflow space for the thermally conductive structural adhesive 300 can be provided. This allows the thermally conductive structural adhesive 300 to overflow between two adjacent battery cell modules 200, further improving the connection stability of the two connected battery cell modules 200.

[0066] The height of the second separator 220 is H4, and H4 / H3 can be any value from 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, or any value between two of these. By reasonably setting the height ratio of the second separator 220 to the cell 210, the height of the second separator 220 covers the cell 210, which facilitates the bonding between the second separator 220 and the cell assembly. It also eliminates the relative displacement space between the cell assemblies, integrating all the cells 210 within the cell module 200 into a single rigid structure. This is beneficial for improving the overall mode of the battery pack and preventing resonance between the battery pack and the vehicle.

[0067] In one embodiment, a heat insulation element is also included, which is located between two adjacent cells 210, and the thickness of the heat insulation element is 1% W1 - 3% W1.

[0068] In this embodiment, along the X direction, the heat insulation component is disposed between two adjacent cells 210. When the cells 210 are charged and discharged, they generate thermal expansion and volume expansion. The heat insulation component is slightly compressed and absorbs the expansion force to evenly distribute the expansion force and prevent the expansion force from acting directly on the cell shell, thus preventing the cell shell from being squeezed and cracked. At the same time, the heat insulation component can rebound when the cells 210 contract, keeping the gap between the cells 210 stable and ensuring that the cell 210 array is always in a constrained state. This helps to improve the overall stiffness of the cell 210 array and the mode of the battery pack.

[0069] The thickness of the heat insulation component is 1% W1 - 3% W1, i.e., 0.2mm-1.8mm. Therefore, the specific thickness of the heat insulation component can be any value or any combination of 0.2mm, 0.5mm, 0.7mm, 1.0mm, 1.2mm, 1.5mm, and 1.8mm. By reasonably setting the thickness of the heat insulation component, it can effectively absorb the small displacements caused by the expansion of the battery cell 210 and provide sufficient elastic buffer space. Moreover, the heat insulation component will not encroach on the arrangement space of the battery cell 210, which can maximize the energy density of the battery pack. At the same time, the heat insulation component can also assist in thermal isolation, effectively blocking heat conduction between the battery cells 210 and preventing the heat insulation component from failing due to compression during expansion. The heat insulation component can be aerogel, heat insulation plate, etc.

[0070] During charge and discharge cycles, the cell 210 will continuously undergo minute volume expansion. If there is no reserved space between the cell module 200 and the housing 100 and the cold plate 400, the expansion force will directly squeeze the cell module 200, causing the cell module 200 to shift and the cell housing to be deformed by compression. Long-term cycling will cause cell tab fatigue, sealing failure, internal lithium plating, etc., directly shortening the cell's EOL (End of Life) cycle life.

[0071] Therefore, as Figure 5As shown, in one embodiment, there is a first overflow portion 310 between two adjacent battery cell modules 200. The height of the first overflow portion 310 is H5, and the height of the longitudinal side beam 110 is H6, satisfying H5 / H6≥1 / 4.

[0072] In this embodiment, the ratio between the height H5 of the first overflow portion 310 and the height H6 of the longitudinal side beam 110 can be any value among 0.25, 0.27, 0.30, 0.32, 0.35, 0.37, and 0.40, or any value between any two of these. When the thermally conductive structural adhesive 300 overflows between two adjacent battery cell modules 200, the first overflow portion 310 is formed along the Z-direction.

[0073] By rationally setting the height ratio of the first overflow section 310 and the longitudinal side beam 110, the first overflow section 310 can be ensured to have sufficient height, thereby providing sufficient buffer space for the expansion of the cell 210 throughout the entire cycle. When the cell 210 expands, the cell module 200 can be slightly displaced in the Y direction, so that the expansion force is absorbed by the first overflow section 310, thereby avoiding the expansion force from acting directly on the cell module 200 or the housing 100, and thus avoiding displacement of the cell 210 or deformation of the cell housing due to compression. When the expansion force is dispersed, the separator, electrolyte, and electrode plates inside the cell 210 are not compressed, which can reduce failure modes such as lithium plating and lithium dendrite growth, directly improving the cell's EOL cycle life, and thus improving the cycle life of the battery pack.

[0074] like Figure 6 As shown, in one embodiment, the housing 100 is provided with a first crossbeam 140. Along the Y direction, the two ends of the first crossbeam 140 are respectively connected to the longitudinal side beam 110. Along the X direction, the width of the first crossbeam 140 is W2, which satisfies 20mm≤W2≤30mm. The longitudinal side beam 110 and the battery cell module 200 have a second overflow part 320. The height of the second overflow part 320 is H7, and the height of the first crossbeam 140 is H8, which satisfies H7 / H8≥1 / 2.

[0075] In this embodiment, the two ends of the first crossbeam 140 along the Y direction are respectively connected to the longitudinal side beams 110 on both sides. Along the X direction, the width W2 of the first crossbeam 140 can be any value among 20mm, 22mm, 24mm, 26mm, 28mm, and 30mm, or any value between any two of these. If the width of the first crossbeam 140 is too small, such as less than 20mm, the first crossbeam 140 is prone to bending deformation, leading to a decrease in the overall rigidity of the housing 100, thereby lowering the battery pack's energy density. If the width of the first crossbeam 140 is too large, such as greater than 30mm, the first crossbeam 140 will encroach on the installation space of the cell module 200 and reduce the number of cells 210, thus reducing the battery pack's energy density. By setting the first crossbeam 140 and appropriately adjusting its width, the two longitudinal side beams 110 can be integrated into a rigid whole, significantly improving the lateral bending and torsional stiffness of the housing 100, thereby enhancing the overall modal characteristics of the battery pack and preventing resonance between the battery pack and the vehicle. Simultaneously, it ensures efficient space utilization of the battery pack housing 100, facilitating an increase in the overall energy density of the battery pack.

[0076] Furthermore, a second adhesive overflow portion 320 is provided between the longitudinal side beam 110 and the battery cell module 200. After the thermally conductive structural adhesive 300 overflows between the longitudinal side beam 110 and the battery cell module 200, the second adhesive overflow portion 320 is formed along the Z direction. The ratio of the height H7 of the second adhesive overflow portion 320 to the height H8 of the first crossbeam 140 can be any value among 0.5, 0.55, 0.6, 0.65, 0.7, and 0.75, or any value between any two of these values.

[0077] By rationally setting the height ratio between the second overflow section 320 and the first crossbeam 140, the second overflow section 320 can be ensured to have sufficient height, thereby providing sufficient buffer space for the expansion of the cell 210 throughout the entire cycle. When the cell 210 expands, the cell module 200 can be slightly displaced in the Y direction, allowing the expansion force to be absorbed by the second overflow section 320, thus avoiding the expansion force from acting directly on the cell module 200 or the housing 100, and preventing the cell 210 from shifting or the cell housing from deforming due to compression. When the expansion force is dispersed, the separator, electrolyte, and electrode plates inside the cell 210 are not compressed, which can reduce failure modes such as lithium plating and lithium dendrite growth, directly improving the cell's EOL cycle life, and thus improving the cycle life of the battery pack.

[0078] In one embodiment, along the X direction, the housing 100 has a first mounting area 170 located on one side of the first crossbeam 140 and a second mounting area 180 located on the other side of the first crossbeam 140, wherein the area ratio of the first mounting area 170 to the area of ​​the second mounting area 180 is 1.1-1.3.

[0079] In this embodiment, along the X direction, the housing 100 is further provided with a second crossbeam 150 and a third crossbeam 160, both ends of the second crossbeam 150 and the third crossbeam 160 along the Y direction are connected to the longitudinal side beams 110; the housing 100 has a first mounting area 170 and a second mounting area 180, wherein the first mounting area 170 and the second mounting area 180 are respectively located on both sides of the first crossbeam 140 along the X direction. Specifically, the first mounting area 170 is formed by the first crossbeam 140, the second crossbeam 150 and a pair of longitudinal side beams 110; the second mounting area 180 is formed by the first crossbeam 140, the third crossbeam 160 and a pair of longitudinal side beams 110.

[0080] Furthermore, the ratio of the area of ​​the first installation area 170 to the area of ​​the second installation area 180 can be any value or a value between any two of 1.1, 1.12, 1.15, 1.17, 1.2, 1.22, 1.25, 1.27, and 1.3. Battery cell modules 200 are installed in both the first installation area 170 and the second installation area 180. The larger the area, the more battery cell modules 200 can be arranged, resulting in a higher mass proportion of that area and a greater shift of the center of gravity towards that area.

[0081] By rationally setting the area ratio of the first installation area 170 to the second installation area 180, the space for cell 210 arrangement in the first installation area 170 is increased, ensuring that the center of gravity of the battery pack always falls within the center of gravity adaptation range of the vehicle chassis, thus meeting the requirements for vehicle driving stability. Moreover, by finely adjusting the area ratio of the first installation area 170 and the second installation area 180, the center of gravity of the battery pack can be matched with the center of gravity of the vehicle with different drive forms, and adapted to models with different wheelbases and track widths, without the need to redesign the structure of the housing 100, thereby achieving platform universality.

[0082] In one embodiment, the cold plate 400 is provided with a plurality of limiting strips 410 arranged at intervals along the Y direction, the limiting strips 410 extending along the X direction and respectively disposed in the first mounting area 170 and the second mounting area 180.

[0083] In this embodiment, a plurality of limiting strips 410 are spaced apart and affixed to the cold plate 400 along the Y direction, and the limiting strips 410 extend along the X direction, such that the limiting strips 410 are disposed within the first mounting area 170 and the second mounting area 180. When the battery cell 210 is installed in the first mounting area 170 and the second mounting area 180, the lower end face of the battery cell 210 abuts against the limiting strips 410. When the thermally conductive structural adhesive 300 is applied to the cold plate 400, the thermally conductive structural adhesive 300 is applied between two adjacent limiting strips 410, so that the amount of thermally conductive structural adhesive 300 between each two limiting strips 410 is consistent, thereby ensuring the uniformity of the adhesion between the battery cell 210 and the cold plate 400, so as to uniformly and stably transfer the heat generated by the battery cell 210 to the thermally conductive structural adhesive 300, and further conduct it quickly to the cold plate 400 through the thermally conductive structural adhesive 300, so as to facilitate the heat dissipation of the battery cell 210.

[0084] According to an embodiment of the present invention, another aspect provides an electrical device including a battery pack. The technical solutions described in the embodiments of the present invention are applicable to various electrical devices using battery packs.

[0085] Electrical equipment can be vehicles, ships, spacecraft, etc. Vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. This invention does not impose any special limitations on the aforementioned electrical equipment.

[0086] For ease of explanation, the following embodiments use a vehicle as an example of an electrical device according to an embodiment of the present invention.

[0087] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery pack is installed inside the vehicle, and the battery pack can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller is used to control the battery pack to power the motor, for example, to meet the power needs of starting, navigation, and driving the vehicle. In other embodiments of the invention, the battery pack can not only serve as the vehicle's operating power source but also as the vehicle's drive power source, replacing or partially replacing gasoline or natural gas to provide driving force for the vehicle.

[0088] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery pack, characterized in that, include: The box body has a pair of longitudinal side beams arranged opposite each other along the Y direction and a pair of transverse side beams arranged opposite each other along the X direction, and the pair of longitudinal side beams and the pair of transverse side beams are connected in sequence to form an installation space; Cold plate, connected to the bottom of the housing along the Z direction; Several battery cell modules are arranged in rows along the X and Y directions within the installation space. The gap H1 between each battery cell module and the adjacent longitudinal side beam satisfies 30mm ≤ H1 ≤ 50mm. The battery cell modules are bonded to the cold plate, and the bonding area between the battery cell module and the cold plate is greater than or equal to 90%. The first partition is bonded between every two adjacent battery cell modules arranged along the Y direction, and the bonding area is greater than or equal to 80%. Each of the battery cell modules includes two rows of battery cell groups arranged along the Y direction, and each battery cell group includes a plurality of battery cells arranged along the X direction; The second partition is bonded between two adjacent cell groups in each cell module, and the bonding area is greater than or equal to 80%. Along the Z direction, the second partition has a first end and a second end, both of which are provided with blocking portions, and the blocking portions are disposed on both sides of the second partition along the Y direction.

2. The battery pack according to claim 1, characterized in that, The length L of the battery cell satisfies 200mm≤L≤500mm, and the width W1 of the battery cell satisfies 20mm≤W1≤60mm. The thickness T of both the first partition and the second partition satisfies 6%W1≤T≤8%W1; The height of the first partition is H2, and the height of the battery cell is H3, satisfying 1 / 3≤H2 / H3≤1 / 2; The height of the second partition is H4, which satisfies H4 / H3≥1.

1.

3. The battery pack according to claim 1, characterized in that, It also includes a heat insulation component located between two adjacent cells, the thickness of which is 1% W1 - 3% W1.

4. The battery pack according to claim 1, characterized in that, There is a first overflow section between two adjacent battery cell modules. The height of the first overflow section is H5, and the height of the longitudinal side beam is H6, satisfying H5 / H6≥1 / 4.

5. The battery pack according to claim 1, characterized in that, The box body is provided with a first crossbeam. Along the Y direction, the two ends of the first crossbeam are respectively connected to the longitudinal side beam. Along the X direction, the width of the first crossbeam is W2, which satisfies 20mm≤W2≤30mm. There is a second overflow section between the longitudinal side beam and the cell module. The height of the second overflow section is H7, and the height of the first crossbeam is H8, satisfying H7 / H8≥1 / 2.

6. The battery pack according to claim 5, characterized in that, Along the X direction, the housing has a first mounting area located on one side of the first crossbeam and a second mounting area located on the other side of the first crossbeam, wherein the area of ​​the first mounting area is 1.1-1.3 to the area of ​​the second mounting area.

7. The battery pack according to claim 6, characterized in that, The cold plate is provided with a plurality of limiting strips arranged at intervals along the Y direction, the limiting strips extending along the X direction and respectively disposed in the first installation area and the second installation area.

8. An electrical appliance, characterized in that, include: The battery pack as described in any one of claims 1 to 7.

Images