Battery pack and electric equipment

Abstract

The present invention relates to the technical field of batteries, and discloses a battery pack and electric equipment, the battery pack comprises: a box body, a longitudinal edge beam and a transverse edge beam of the box body are sequentially connected to define a mounting space for mounting a battery cell module; the supporting plate is connected to the bottom of the box body; the battery cell is adhered to the supporting plate; the cold plate is adhered to the upper end surface of the battery cell and covers the box body, and the height H1 of the cold plate and the height H2 of the supporting plate meet the condition that H1 / H2 is more than or equal to 0.65 and less than or equal to 0.8; a hollow area is arranged on the supporting plate, and the explosion-proof valve of the battery cell corresponds to the hollow area. The box body, the supporting plate, the cold plate and the battery cell module form a rigid whole, and the height ratio of the cold plate to the supporting plate is reasonably set, so that the rigidity of the battery pack and the overall mode of the battery pack are improved, the resonance resistance of the battery pack is enhanced, the situation that the mode of the battery pack coincides with the resonance frequency of a whole vehicle is avoided, and the reliability of the battery pack is improved. The overall safety and reliability of the battery pack are ensured; and the explosion-proof valve and the cold plate are respectively arranged at two ends of the battery cell, so that thermoelectric separation is realized.

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] A battery pack is generally composed of multiple battery cells. Battery cells, such as lithium-ion cells, are widely used in various fields including transportation power supplies, power storage, new energy storage power supplies, aerospace, and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. Battery pack modes refer to the inherent vibration characteristics of the battery pack structure system itself. They reflect the vibration patterns and response laws of the battery pack at different frequencies and are an important aspect of battery pack structural dynamics analysis.

[0003] When battery packs are used in electric vehicles, traditional battery packs have low overall stiffness, making them prone to resonance with the vehicle. This results in low battery pack modes, which can damage or fail the battery pack structure, thus affecting the performance and safety of the electric vehicle. Furthermore, the explosion-proof valves for the battery cells are typically located on the top or side of the cells, failing to effectively achieve thermal-electric separation, which also impacts the safety performance of the battery pack. Summary of the Invention

[0004] In view of this, the present invention provides a battery pack and electrical device to solve the problems of structural damage or failure of the battery pack due to resonance caused by low battery pack stiffness and low safety performance of the battery pack due to the inability of the battery cells to effectively achieve thermoelectric separation.

[0005] In a first aspect, the present invention provides a battery pack, comprising: 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; Several battery cell modules are arranged in rows along the X and Y directions in the installation space, and each battery cell module has several battery cells arranged sequentially along the X direction. A support plate is connected to the bottom of the housing along the Z direction, and the lower end face of the battery cell is bonded to the support plate. A cold plate is bonded to the upper end face of the battery cell and covers the upper end face of the housing. The height H1 of the cold plate satisfies 5mm≤H1≤7mm, and the height H2 of the support plate satisfies 8mm≤H2≤12mm and 0.65≤H1 / H2≤0.8. The support plate is provided with several hollow areas extending along the X direction at intervals along the Y direction, and the lower end face of the battery cell is provided with an explosion-proof valve, which corresponds to the hollow area.

[0006] Beneficial effects: By connecting the support plate to the bottom of the housing, bonding the lower end face of the battery cell to the support plate, bonding the cold plate to the upper end face of the battery cell, and covering the upper end face of the housing with the cold plate, the housing, support plate, cold plate, and battery cell module form a rigid whole, effectively improving the rigidity of the battery pack. Furthermore, by rationally setting the ratio of the height of the cold plate to the height of the support plate, the supporting rigidity of the support plate along the Z-direction and the pressing rigidity of the cold plate along the Z-direction can be guaranteed, preventing rigidity breaks in the battery pack and avoiding stiffness imbalances between the support plate and the cold plate. This effectively improves the overall modal characteristics of the battery pack, strengthens its anti-resonance capability, prevents the inherent modes of the battery pack from coinciding with the resonant frequency of the vehicle, and ensures the overall safety and reliability of the battery pack.

[0007] Furthermore, several hollow areas extending in the X direction are spaced apart along the Y direction on the support plate. The extension direction of these hollow areas is consistent with the arrangement direction of the battery cells, allowing the explosion-proof valve of each battery cell to face the hollow area directly. At the bottom of the battery pack, the hollow areas provide a path for the high-temperature gas to escape in the event of thermal runaway, preventing the accumulation of high-temperature gas inside the battery pack. Moreover, placing the explosion-proof valve on the lower end face of the battery cell along the Z direction avoids intersection between the explosion-proof valve and the cold plate and conductive components on the upper end face of the battery cell along the Z direction, thereby achieving thermal-electric separation and improving the safety performance of the battery pack.

[0008] In one optional embodiment, the bonding area between the upper end face of the battery cell and the cold plate accounts for ≥80% of the area of ​​the upper end face of the battery cell; the bonding area between the lower end face of the battery cell and the support plate accounts for ≥50% of the area of ​​the lower end face of the battery cell.

[0009] Beneficial effects: By rationally setting the bonding area between the battery cell and the cold plate, the battery cell can make full contact with the cold plate, thereby effectively improving the overall structural rigidity of the battery pack and resulting in a higher natural mode. This avoids the natural mode of the battery pack coinciding with the resonant frequency of the vehicle, ensuring the overall safety and reliability of the battery pack. By rationally setting the bonding area between the lower end face of the battery cell and the cold plate, the battery cell can make full contact with the support plate, providing sufficient adhesive force to prevent the battery cell from sliding or tipping over on the support plate. Simultaneously, the weight and load of the battery cell are evenly transferred to the support plate and the housing, avoiding localized stress concentration that could lead to deformation of the support plate. This effectively improves the overall structural rigidity of the battery pack, resulting in a higher natural mode.

[0010] In one optional embodiment, the housing is provided with a longitudinal beam extending along the X direction and a plurality of transverse beams extending along the Y direction, all disposed within the installation space, for dividing the installation space into a plurality of sub-installation spaces, each of the sub-installation spaces being used to store the battery cell module; Along the Y direction, both ends of the crossbeam are connected to the longitudinal side beam, and the width of the crossbeam is 15mm-40mm; The two ends of the longitudinal beam are respectively connected to the transverse beam near the transverse side beam, and the width of the longitudinal beam is 15mm-40mm; The ratio of the height H3 of the crossbeam to the height H4 of the longitudinal beam satisfies H3 / H4≥2.

[0011] Beneficial effects: By rationally setting the width of the crossbeams and / or longitudinal beams, the two longitudinal side beams, three crossbeams, and longitudinal beams can be integrated into a rigid whole, significantly improving the lateral bending and torsional stiffness of the battery pack, 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 within the battery pack housing, facilitating an increase in the overall energy density of the battery pack. By designing the crossbeam height to be twice or more than the longitudinal beam height, the crossbeam's ability to bear loads in the Y direction can be significantly improved, provided the widths of the crossbeams and longitudinal beams are the same. This effectively resists bending deformation in the middle of the housing caused by Y-direction loads; it also prevents torsional deformation of the crossbeams themselves, ensuring the shape accuracy of the sub-installation space and preventing the cell modules from being squeezed or shifted due to crossbeam deformation.

[0012] In one optional embodiment, the ratio of the height H5 of the battery cell to the height H6 of the housing satisfies 0.9 ≤ H5 / H6 ≤ 0.95; The ratio of the height H3 of the crossbeam to the height H5 of the battery cell satisfies H3 / H5≥0.8.

[0013] Beneficial effects: By rationally setting the ratio of cell height to casing height, the space utilization of the casing can be effectively improved, ensuring the energy density of the battery pack. Furthermore, it allows for deformation space to accommodate the thermal expansion of the cells, preventing the expanded cells from squeezing the casing and crossbeams, thus ensuring the overall rigidity of the battery pack. By rationally setting the ratio of crossbeam height to cell height, the crossbeam provides sufficient and continuous support surface for the cells, effectively limiting the travel of the cell module in the Y-direction. This prevents the cell module from shifting in the Y-direction when the vehicle turns or changes lanes, ensuring the adhesion between the cells and the support plate and cooling plate, thereby guaranteeing the overall rigidity of the battery pack.

[0014] In one optional embodiment, the length of the housing along the X direction is L1, satisfying 600mm≤L1≤2200mm; the width of the housing along the Y direction is W1, satisfying 800mm≤W1≤1500mm; the length of the battery cell is L2, satisfying 250mm≤L2≤600mm; the width of the battery cell is W2, satisfying 10mm≤W2≤30mm; and the ratio of the length L2 of the battery cell to the width W1 of the housing satisfies L2 / W1≥0.3.

[0015] Beneficial effects: By rationally setting the ratio of cell length to box width, the volume utilization rate of the battery pack can be effectively improved, facilitating an increase in the overall energy density of the battery pack. Furthermore, the longer the cell, the larger the contact area between the cell module and the crossbeam, resulting in a more uniform support force from the crossbeam on the cell module. This effectively disperses the load along the Y-direction of the crossbeam, preventing localized stress concentration and improving the overall rigidity of the battery pack.

[0016] In one optional embodiment, the battery cell is a ternary battery cell, and there is a gap between two adjacent battery cells. The gap includes a first gap and a second gap, which are arranged sequentially. The first gap is 3mm-5mm, the second gap is 1mm-2mm, and the sum of the first gap and the second gap is 1 / 6 W2-1 / 3 W2.

[0017] Beneficial effects: By setting the first gap reasonably, when the ternary system cell experiences thermal runaway, the first gap can effectively block the hot airflow from directly contacting the adjacent cells, while providing space for natural heat convection, avoiding heat accumulation between cells, and reducing the risk of cell-chain thermal runaway; moreover, it avoids the first gap being too large, ensuring the compactness of the cell arrangement and effectively improving the volume utilization rate of the battery pack.

[0018] By properly setting the second gap, the expansion and deformation of ternary lithium-ion cells during charge and discharge cycles can be effectively accommodated, preventing deformation of the cell shell or wrinkling of the internal electrode sheets due to mutual compression after expansion, thus ensuring the safety performance of the cells. At the same time, the second gap avoids reducing the space utilization rate of the battery pack.

[0019] Furthermore, by reasonably setting the ratio of the sum of the first gap and the second gap to the width of the battery cell, the width of the battery cell can be adapted to ensure that the battery cell provides sufficient buffer for expansion under different width conditions, so that the force is uniform when the battery cell expands due to collision, which is beneficial to the battery cell's cycle.

[0020] In one optional embodiment, the battery cell is a lithium iron phosphate battery cell, and there is a third gap between two adjacent battery cells, the third gap being 0.5mm-1mm and having a weight of 1% W2-5% W2.

[0021] Beneficial effects: By rationally setting the third gap, a buffer space is provided for cell expansion, preventing damage to the cell casing caused by expansion force acting directly on it, thus avoiding short circuits. It also effectively reduces the distance between cells, improving the space utilization of the casing along the X-direction and facilitating an increase in the overall energy density of the battery pack. Furthermore, by rationally setting the proportion of the third gap to the cell width to accommodate cell widths, sufficient buffering is effectively ensured for cell expansion under different widths, resulting in uniform force distribution during cell collision and expansion, which is beneficial for cell cycle life.

[0022] In one optional embodiment, a bottom protective plate is further included, located below the support plate along the Z direction and connected to the housing. The bottom of the support plate is provided with a protrusion protruding towards the bottom protective plate, and the protrusion abuts against the bottom protective plate. In the hollow area, the support plate and the bottom protective plate form an exhaust channel, and the explosion-proof valve is located in the exhaust channel.

[0023] Beneficial effects: Each support plate has a protrusion extending towards the bottom protective plate. This protrusion abuts against the bottom protective plate, creating cavities between the bottom protective plate and the support plate. This increases the distance between the outside environment and the battery cell module. When the bottom of the battery pack is impacted, the protective structure formed by the bottom protective plate and the support plate increases the load-bearing capacity of the battery pack. Multiple cavities enhance energy absorption, better resisting external damage and maximizing battery pack safety. By placing the exhaust channel at the bottom of the battery pack, it is completely isolated from the top cold plate. High-temperature gases will not contact the cold plate or the thermally conductive adhesive, preventing damage to the battery pack's heat dissipation system and ensuring efficient heat dissipation during normal cell operation.

[0024] In an optional embodiment, a battery pack circuit breaker unit is further included, located between the transverse side beam and a beam close to the transverse side beam, and connected to the housing. The battery pack circuit breaker unit abuts against the lower end face of the cold plate along the Z direction, and a heat-conducting element is provided between the battery pack circuit breaker unit and the cold plate.

[0025] Beneficial effects: By placing the Battery Disconnect Unit (BDU) in the reserved space between the transverse side beam of the enclosure and the crossbeam close to the transverse side beam, and fixing the BDU to the enclosure, the BDU can realize the integrated arrangement of electrical safety components by utilizing the structural space between the transverse side beam and the crossbeam, without compressing the effective installation space of the cell module, effectively ensuring the volumetric energy density of the battery pack and fully ensuring the volume utilization rate of the battery pack.

[0026] Furthermore, the BDU is placed against the lower end face of the cold plate along the Z direction, and a heat-conducting component is set between the BDU and the cold plate. This allows the cold plate to dissipate heat for both the battery cell and the BDU, and effectively eliminates the gap between the BDU and the cold plate. This allows heat to be transferred directly through the heat-conducting component with a high thermal conductivity, significantly reducing the thermal resistance of the contact and thus ensuring the heat dissipation efficiency of the BDU.

[0027] Secondly, the present invention also provides an electrical device, comprising: a battery pack as described above.

[0028] 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

[0029] 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.

[0030] Figure 1 This is a schematic diagram of the exploded structure of a battery pack according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a battery pack housing according to an embodiment of the present invention; Figure 3 for Figure 2 Cross-sectional view along the middle AA; Figure 4 This is a bottom view of the casing of a battery pack according to an embodiment of the present invention; Figure 5 for Figure 4 Cross-sectional view along the middle BB; Figure 6 for Figure 5 A magnified view of part of C; Figure 7 for Figure 5 A magnified view of part of D; Figure 8 for Figure 5 A magnified view of part of E in the diagram; Figure 9 This is a schematic diagram of the structure of a cell module in a battery pack according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of a cold plate and a battery pack circuit breaker unit in a battery pack according to an embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures: 100. Housing; 110. Longitudinal side beam; 120. Transverse side beam; 130. Longitudinal beam; 140. Transverse beam; 200. Battery cell module; 210. Battery cell; 300. Support plate; 310. Hollowed-out area; 320. Protrusion; 400. Cold plate; 500. Bottom protective plate; 600. Battery pack circuit breaker unit; 700. Insulation cotton. Detailed Implementation

[0032] 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.

[0033] The following is combined Figures 1 to 10 The following describes embodiments of the present invention.

[0034] According to embodiments of the present invention, in one aspect, such as Figures 1 to 6 , Figure 9 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 sequentially connected to form an installation space; a plurality of battery cell modules 200, arranged in rows along the X and Y directions respectively within the installation space, the battery cell module 200 having a plurality of battery cells 210 arranged sequentially along the X direction; and a support plate 300 connected to the bottom of the housing 100 along the Z direction, the battery cells 210 being... The lower end face of the cell 210 is bonded to the support plate 300; the cold plate 400 is bonded to the upper end face of the cell 210 and covers the upper end face of the housing 100. The height H1 of the cold plate 400 satisfies 5mm≤H1≤7mm, and the height H2 of the support plate 300 satisfies 8mm≤H2≤12mm and 0.65≤H1 / H2≤0.8. The support plate 300 is provided with a number of hollow areas 310 extending in the X direction along the Y direction. The lower end face of the cell 210 is provided with an explosion-proof valve, which corresponds to the hollow area 310.

[0035] 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 end of the housing 100 has an opening, allowing the cell module 200 to be installed into the housing 100 through the opening at the top.

[0036] Several 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. Each cell module 200 has several cells 210 arranged sequentially along the X direction, and end plates are provided at both ends of the cell module 200, while side plates are provided on both sides of the cell module 200 to protect the cells 210.

[0037] A support plate 300 is connected to the bottom of the housing 100 along the Z-direction, and the lower end face of the battery cell 210 is bonded to the support plate 300, providing a stable mounting base for the battery cell 210. Along the Z-direction, a cold plate 400 is bonded to the upper end face of the battery cell 210 using thermally conductive structural adhesive to form a stable structural connection; furthermore, the cold plate 400 covers the upper end face of the housing 100 and is connected to the housing 100, allowing it to seal any openings above the housing 100. The cold plate 400 has cooling channels through which coolant flows, quickly dissipating heat from the battery cell module 200 during operation and preventing thermal runaway of the battery cell 210.

[0038] By connecting the support plate 300 to the bottom of the housing 100, bonding the lower end face of the battery cell 210 to the support plate 300, bonding the cold plate 400 to the upper end face of the battery cell 210, and covering the upper end face of the housing 100, the housing 100, the support plate 300, the cold plate 400, and the battery cell module 200 form a rigid whole, which can effectively improve the rigidity of the battery pack.

[0039] Furthermore, an explosion-proof valve is provided on the lower end face of the cell 210 along the Z direction. When a large amount of gas is generated inside the cell 210 due to overheating, short circuit, or other problems, the explosion-proof valve can rupture and release gas in time, preventing the cell 210 from exploding. Several hollow areas 310 extending along the X direction are spaced apart along the Y direction on the support plate 300. The extension direction of these hollow areas 310 is consistent with the arrangement direction of the cells 210, ensuring that the explosion-proof valve of each cell 210 faces the hollow area 310. The hollow areas 310 at the bottom of the battery pack provide a path for the high-temperature gas generated during thermal runaway of the cell 210, preventing the high-temperature gas from accumulating inside the battery pack. Moreover, placing the explosion-proof valve on the lower end face of the cell 210 along the Z direction prevents the explosion-proof valve from intersecting with the cold plate 400 on the upper end face of the cell 210 along the Z direction, preventing the high-temperature gas from burning the cold plate 400 when the cell 210 depressurizes, and avoiding secondary accidents involving the cell 210. Furthermore, by placing the explosion-proof valve on the lower end face of the cell 210, the explosion-proof valve can be separated from conductive components such as the terminal post and busbar. This can prevent high-temperature exhaust gas from contacting the conductive area, thereby avoiding secondary accidents such as short circuits in the cell 210. This achieves thermal-electric separation of the cell 210, which is beneficial to improving the safety performance of the battery pack.

[0040] Furthermore, the cold plate 400 and the support plate 300 serve as rigid end plates at the upper and lower ends of the housing 100 along the Z-direction. The height ratio of the cold plate 400 and the support plate 300 directly affects the uniformity of the overall stiffness of the housing 100 along the Z-direction. If the heights of the cold plate 400 and the support plate 300 are mismatched, an imbalance in stiffness between the support plate 300 and the cold plate 400 will occur, leading to a decrease in the overall modal strength of the housing 100. The support plate 300, as the bottom load-bearing component of the battery pack, directly bears the weight of the battery cell 210 and requires a pre-reserved hollow area 310. The hollow area 310 will cause a local stiffness loss in the support plate 300. Therefore, a higher height is needed to compensate for the stiffness reduction caused by the hollow area 310 to ensure the overall load-bearing capacity of the bottom of the battery pack. The cold plate 400, as the top load-bearing component of the battery pack, mainly bears the static pressure and vibration loads of the top of the vehicle. Since the cold plate has no hollow design, it does not need to be too high to meet the load-bearing requirements.

[0041] The height H1 of the cold plate 400 can be any value of 5mm, 5.5mm, 6mm, 6.5mm, or 7mm, or any value between any two of these values; the height H2 of the support plate 300 can be any value of 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, or 12mm, or any value between any two of these values; the ratio H1 / H2 of the height H1 of the cold plate 400 to the height H2 of the support plate 300 can be any value of 0.65, 0.67, 0.69, 0.71, 0.73, 0.75, 0.77, or 0.8, or any value between any two of these values. If H1 / H2 is too small, such as less than 0.65, the height of the cold plate 400 will be too low, thus relatively reducing the stiffness of the cold plate 400 along the Z direction. This makes the cold plate 400 a weak point in the rigid structure along the Z direction. Simultaneously, the low height of the cold plate will affect the height of the flow channels, impacting the coolant flow rate and consequently affecting the cooling and heating rates of the battery pack. When the battery pack is subjected to vibration loads, the top cold plate 400 will undergo significant bending deformation due to insufficient stiffness, directly leading to a decrease in the overall modal characteristics of the battery pack. This can cause resonance between the battery pack and the vehicle, resulting in battery pack failure. If H1 / H2 is too large, such as greater than 0.8, the height of the cold plate 400 will be too high, resulting in an excessively high overall height of the battery pack. This may not meet the vehicle chassis space requirements, preventing the battery pack from being installed under the vehicle. If the overall height of the battery pack is relatively reduced by lowering the height of the cell 210, the capacity of the cell 210 will be directly reduced, leading to a decrease in the volumetric energy density and gravimetric energy density of the battery pack.

[0042] By appropriately setting the ratio of the height of the cold plate 400 to the height of the support plate 300, the supporting stiffness of the support plate 300 along the Z-direction and the pressing stiffness of the cold plate 400 along the Z-direction can be guaranteed. This prevents stiffness discontinuity in the battery pack as a whole and avoids stiffness imbalance between the support plate 300 and the cold plate 400, thereby effectively improving the overall modal characteristics of the battery pack and enhancing its anti-resonance capability. This prevents the battery pack's inherent modes from coinciding with the vehicle's resonance frequency, ensuring the overall safety and reliability of the battery pack. Furthermore, it allows the battery pack to adapt to the vehicle's chassis space and maintains its energy density.

[0043] In one embodiment, the bonding area between the upper end face of the battery cell 210 and the cold plate 400 accounts for ≥80% of the area of ​​the upper end face of the battery cell 210; the bonding area between the lower end face of the battery cell 210 and the support plate 300 accounts for ≥50% of the area of ​​the lower end face of the battery cell 210.

[0044] In this embodiment, the bonding area between the upper surface of the battery cell 210 and the cold plate 400 can be any value or a value between any two of the following: 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, 96%, 98%, and 100%. By ensuring that the bonding area between the upper surface of the battery cell 210 and the cold plate 400 is greater than or equal to 80% of the upper surface area of ​​the battery cell 210, the air gap between the battery cell 210 and the cold plate 400 can be effectively eliminated, thereby ensuring the thermal conductivity between the battery cell 210 and the cold plate 400. Furthermore, by rationally setting the bonding area between the battery cell 210 and the cold plate 400, sufficient contact between the battery cell 210 and the cold plate 400 can be achieved, thereby effectively improving the overall structural rigidity of the battery pack and resulting in a higher natural mode of the battery pack. This avoids the natural mode of the battery pack coinciding with the resonant frequency of the vehicle, ensuring the overall safety and reliability of the battery pack.

[0045] The bonding area between the lower end face of the battery cell 210 and the cold plate 400 can be any value among 50%, 55%, 60%, 65%, 70%, 75%, and 80%, or any value between two of these. By ensuring that the bonding area between the lower end face of the battery cell 210 and the cold plate 400 is greater than or equal to 50% of the area of ​​the lower end face of the battery cell 210, sufficient contact between the battery cell 210 and the support plate 300 can be achieved, providing adequate adhesive force to prevent the battery cell 210 from sliding or tipping over on the support plate 300. Simultaneously, the weight and load of the battery cell 210 are evenly distributed to the support plate 300 and the housing 100, avoiding localized stress concentration that could lead to deformation of the support plate 300. This effectively improves the overall structural rigidity of the battery pack, resulting in higher inherent modes of the battery pack.

[0046] Understandably, the bonding area between the lower end face of the battery cell 210 and the cold plate 400 can be reasonably set according to the usage requirements to ensure that the support plate 300 has a sufficient hollow area 310 to prevent the explosion-proof valve from failing to open effectively when the battery cell 210 thermally runs away, which would prevent the high-temperature gas inside the battery pack from being discharged, thereby causing a sudden increase in the internal pressure of the battery pack and the rupture of the casing 100 and other serious safety accidents.

[0047] like Figure 7As shown, in one embodiment, the housing 100 is provided with a longitudinal beam 130 extending along the X direction and a plurality of transverse beams 140 extending along the Y direction, all of which are arranged within the installation space to divide the installation space into a plurality of sub-installation spaces, each of which is used to store the battery cell module 200; along the Y direction, the two ends of the transverse beam 140 are respectively connected to the longitudinal side beam 110, and the width of the transverse beam 140 is 15mm-40mm; the two ends of the longitudinal beam 130 are respectively connected to the transverse beam 140 near the transverse side beam 120, and the width of the longitudinal beam 130 is 15mm-40mm; the ratio of the height H3 of the transverse beam 140 to the height H4 of the longitudinal beam 130 satisfies H3 / H4≥2.

[0048] In this embodiment, both the crossbeams 140 and the longitudinal beams 130 are disposed within the installation space. There are three crossbeams 140, arranged along the X direction and extending along the Y direction, such that both ends of the three crossbeams 140 along the Y direction are connected to the longitudinal side beams 110 on both sides. The longitudinal beams 130 extend along the X direction, with both ends of the longitudinal beams 130 connected to the crossbeams 140 on the side closest to the transverse side beams 120. The crossbeams 140 and longitudinal beams 130 work together to divide the installation space into four independent sub-installation spaces, each of which can accommodate several battery cell modules 200.

[0049] The width of the crossbeam 140 can be any value or a value between any two of 15mm, 20mm, 25mm, 30mm, 35mm, and 40mm; the width of the longitudinal beam 130 can be any value or a value between any two of 15mm, 20mm, 25mm, 30mm, 35mm, and 40mm. If the width of the crossbeam 140 and / or the longitudinal beam 130 is too small, such as less than 15mm, the crossbeam 140 and / or the longitudinal beam 130 are prone to bending deformation, resulting in a decrease in the overall rigidity of the housing 100, thereby reducing the energy density of the battery pack. If the width of the crossbeam 140 and / or the longitudinal beam 130 is too large, such as greater than 40mm, the crossbeam 140 and / or the longitudinal beam 130 will encroach on the installation space of the cell module 200 and reduce the number of cells 210, thereby reducing the energy density of the battery pack. By appropriately setting the widths of the crossbeams 140 and / or the longitudinal beams 130, the two longitudinal side beams 110, the three crossbeams 140, and the longitudinal beams 130 can be integrated into a rigid whole, significantly improving the lateral bending and torsional stiffness of the battery pack 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.

[0050] Furthermore, the ratio of the height H3 of the crossbeam 140 to the height H4 of the longitudinal beam 130 can be any value from 2, 2.1, 2.2, 2.3, 2.4, 2.5, or any value between two of these. During vehicle operation, centrifugal forces or lateral impact forces, such as those experienced during turning, lane changes, and emergency braking, mostly act on the battery pack along the Y direction; while the load along the X direction is relatively small. Therefore, the crossbeam 140 is the direct load-bearing component in the Y direction and needs sufficient height to improve its bending and torsional stiffness. By designing the height of the crossbeam 140 to be twice or more than that of the longitudinal beam 130, the ability of the crossbeam 140 to bear loads in the Y direction can be significantly improved, provided that the widths of the crossbeam 140 and the longitudinal beam 130 are the same. This effectively resists the bending deformation of the middle part of the housing 100 caused by Y-direction loads; it also prevents the crossbeam 140 itself from undergoing torsional deformation, ensuring the shape accuracy of the sub-installation space and preventing the cell module 200 from being squeezed or shifted due to the deformation of the crossbeam 140.

[0051] In one embodiment, the ratio of the height H5 of the battery cell 210 to the height H6 of the housing 100 satisfies 0.9≤H5 / H6≤0.95; the ratio of the height H3 of the crossbeam 140 to the height H5 of the battery cell 210 satisfies H3 / H5≥0.8.

[0052] In this embodiment, the ratio H5 / H6 of the height H5 of the battery cell 210 to the height H6 of the housing 100 can be any value or any two values ​​from 0.9, 0.91, 0.92, 0.93, 0.94, and 0.95. If the ratio of the height of the battery cell 210 to the height of the housing 100 is too small, such as less than 0.9, there will be spatial redundancy in the housing 100 along the Z direction, thereby reducing the overall space utilization of the housing 100. If the ratio of the height of the battery cell 210 to the height of the housing 100 is too large, such as greater than 0.95, the expanded battery cell 210 will directly compress the side beams and internal crossbeams 140 of the housing 100 during charge and discharge cycles, thereby causing problems such as deformation of the housing 100, damage to the battery cell 210 under pressure, and breakage of the electrode tabs. By reasonably setting the ratio of the height of the battery cell 210 to the height of the housing 100, the space utilization of the housing 100 can be effectively improved, ensuring the energy density of the battery pack. Furthermore, space is reserved for the thermal expansion of the battery cell 210 to prevent the expanded battery cell 210 from squeezing the housing 100 and the crossbeam 140, thereby ensuring the overall rigidity of the battery pack.

[0053] Furthermore, the ratio H3 / H5 of the height H3 of the crossbeam 140 to the height H5 of the cell 210 can be any value or any two values ​​from 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, and 0.90. By reasonably setting the ratio of the height of the crossbeam 140 to the height of the cell 210, the crossbeam 140 provides a sufficient and continuous support surface for the cell 210, effectively limiting the travel of the cell module 200 in the Y direction. This prevents the cell module 200 from shifting in the Y direction when the vehicle turns or changes lanes, ensuring the bonding effect between the cell 210 and the support plate 300 and the cold plate 400, thereby ensuring the overall rigidity of the battery pack.

[0054] like Figure 8 As shown, in one embodiment, the length of the housing 100 along the X direction is L1, satisfying 600mm≤L1≤2200mm, and the width of the housing 100 along the Y direction is W1, satisfying 800mm≤W1≤1500mm; the length of the battery cell 210 is L2, satisfying 250mm≤L2≤600mm, and the width of the battery cell 210 is W2, satisfying 10mm≤W2≤30mm; the ratio of the length L2 of the battery cell 210 to the width W1 of the housing 100 satisfies L2 / W1≥0.3.

[0055] In this embodiment, the length L1 of the housing 100 along the X direction can be any value or any combination of two of the following: 600mm, 800mm, 1000mm, 1200mm, 1400mm, 1600mm, 1800mm, 2000mm, and 2200mm. The width W1 of the housing 100 along the Y direction can be any value or any combination of two of the following: 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, and 1500mm. The length L2 of the battery cell 210 can be any value or any combination of two of the following: 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, and 600mm. The width W2 of the battery cell 210 can be any value or any combination of two of the following: 10mm, 15mm, 20mm, 25mm, and 30mm.

[0056] The ratio of the length L2 of the battery cell 210 to the width W1 of the housing 100 can be any value from 0.3, 0.33, 0.36, 0.39, 0.42, 0.45, and 0.48, or any value between any two. If the ratio of the length of the battery cell 210 to the width of the housing 100 is too small, such as less than 0.3, the width of the housing 100 will be much larger than the length of the battery cell 210, resulting in an excessively small overall volume of the battery cell 210. With a fixed number of battery cell modules 200, this significantly reduces the energy density of the battery pack. Even if the number of battery cell modules 200 can be appropriately increased, the gaps between the battery cell modules 200 will still relatively reduce the space utilization rate of the housing 100, similarly reducing the energy density of the battery pack. By reasonably setting the ratio of the length of the battery cell 210 to the width of the housing 100, the volume utilization rate of the battery pack can be effectively improved, facilitating an increase in the overall energy density of the battery pack. Moreover, the longer the cell 210 is, the larger the contact area between the cell module 200 and the crossbeam 140, and the more uniform the supporting force of the crossbeam 140 on the cell module 200, so as to effectively disperse the load of the crossbeam 140 along the Y direction, avoid local stress concentration of the crossbeam 140, and help improve the overall rigidity of the battery pack.

[0057] In one embodiment, the battery cell 210 is a ternary battery cell, and there is a gap between two adjacent battery cells 210. The gap includes a first gap and a second gap, which are arranged sequentially. The first gap is 3mm-5mm, the second gap is 1mm-2mm, and the sum of the first gap and the second gap is 1 / 6 W2-1 / 3 W2.

[0058] In this embodiment, the ternary lithium battery cell is a cell 210 that uses lithium nickel cobalt manganese or lithium nickel cobalt aluminum oxide as the positive electrode material. After thermal runaway, the ternary lithium battery cell rapidly releases high-temperature gas and heat. If the gaps between adjacent cells 210 are equidistant and too small, heat will rapidly accumulate within the gaps, triggering a chain reaction of thermal runaway. If the gaps are equidistant and too large, it will sacrifice the space utilization of the battery pack and reduce its energy density. Therefore, a first gap and a second gap with unequal spacing are provided between two adjacent cells 210, and the first gap and the second gap are arranged alternately along the cell 210 arrangement direction to reserve space for thermal diffusion buffering, expansion deformation, and passive heat dissipation for the cells 210.

[0059] The first gap can be any value from 3mm, 3.5mm, 4mm, 4.5mm, and 5mm, or any value between two of these. By reasonably setting the first gap, when the ternary lithium battery cell experiences thermal runaway, the first gap can effectively block the hot airflow from directly contacting adjacent cells 210, while providing space for natural heat convection, preventing heat accumulation between cells 210, and reducing the risk of cascading thermal runaway of cells 210; moreover, it avoids the first gap being too large, ensuring the compact arrangement of cells 210 and effectively improving the volume utilization rate of the battery pack.

[0060] The second gap can be any value from 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, and 2mm, or any value between two of these. By properly setting the second gap, the expansion and deformation of the ternary lithium-ion battery cells during charge and discharge cycles can be effectively accommodated, preventing deformation of the cell 210 casing or wrinkling of the internal electrode sheets due to mutual compression after expansion, thus ensuring the safety performance of the cell 210. At the same time, the space utilization rate of the battery pack is not reduced due to the second gap.

[0061] Furthermore, the ratio of the sum of the first gap and the second gap to the width of the battery cell 210 can be any value among 1 / 6 W², 2 / 9 W², 5 / 18 W², and 1 / 3 W², or any value between two of these. By reasonably setting the ratio of the sum of the first gap and the second gap to the width of the battery cell 210 to adapt to the width of the battery cell 210, it is possible to effectively ensure that the expansion of the battery cell 210 is adequately buffered under different width conditions, so that the force is uniform when the battery cell 210 expands due to collision, which is beneficial to the cycling of the battery cell 210.

[0062] In one embodiment, the cell 210 is a lithium iron phosphate cell, and there is a third gap between two adjacent cells 210. The third gap is 0.5mm-1mm and is 1% W2-5% W2.

[0063] In this embodiment, the lithium iron phosphate (LFP) battery cell 210 uses lithium iron phosphate as the positive electrode material and carbon as the negative electrode material. The thermal runaway triggering conditions for the LFP battery cell 210 are stringent; even if a single cell 210 experiences thermal runaway, the heat release is slow and the thermal diffusion distance is short. Therefore, by setting an equally spaced third gap between two adjacent cells 210, the thermal expansion requirements of the LFP battery cell can still be met. The third gap can be any value from 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm, or a value between any two of these values.

[0064] By rationally setting the third gap, a buffer space is provided for the expansion of the cell 210, avoiding damage to the cell casing caused by the expansion force acting directly on the cell casing, which could lead to a short circuit in the cell 210. At the same time, the distance between each cell 210 is effectively reduced, thereby effectively improving the space utilization rate of the casing 100 along the X direction and facilitating the improvement of the overall energy density of the battery pack.

[0065] Furthermore, the ratio of the third gap to the width of the cell 210 can be any value among 1%W2, 2%W2, 3%W2, 4%W2, and 5%W2, or any value between two of these. By reasonably setting the ratio of the third gap to the width of the cell 210 to adapt to the width of the cell 210, it is possible to effectively ensure that the expansion of the cell 210 is adequately buffered under different width conditions, so that the force is uniform when the cell 210 expands due to collision, which is beneficial to the cycle life of the cell 210.

[0066] In one embodiment, a bottom guard plate 500 is also included, located below the support plate 300 along the Z direction and connected to the housing 100. The bottom of the support plate 300 is provided with a protrusion 320 protruding towards the bottom guard plate 500, and the protrusion 320 abuts against the bottom guard plate 500. At the hollow area 310, the support plate 300 and the bottom guard plate 500 form an exhaust channel, and an explosion-proof valve is located at the exhaust channel.

[0067] In this embodiment, the bottom protective plate 500 is bolted to the bottom of the housing 100 and positioned below the support plate 300. This allows the bottom protective plate 500 to protect the support plate 300 and the cell module 200 from external physical damage, preventing the cell 210's explosion-proof valve from being exposed or damaged due to breakage of the support plate 300. Each support plate 300 has a protrusion 320 extending towards the bottom protective plate 500 at its bottom. This protrusion 320 abuts against the bottom protective plate 500, creating cavities between the bottom protective plate 500 and the support plate 300. This increases the distance between the outside environment and the cell module 200. When the bottom of the battery pack housing 100 is impacted, the protective structure formed by the bottom protective plate 500 and the support plate 300 increases the load-bearing capacity of the battery pack housing 100. The multiple cavities enhance energy absorption, better resisting external damage and maximizing battery pack safety.

[0068] Furthermore, at the hollowed-out area 310, the support plate 300 and the bottom protective plate 500 cooperate to form an exhaust channel extending in the X direction, and all the explosion-proof valves of the battery cells 210 correspond to the exhaust channel. In the event of thermal runaway in the battery cell 210, the high-temperature gas inside the battery cell 210 can be discharged from the explosion-proof valve and discharged to the hollowed-out area 310; then the high-temperature gas can be quickly discharged from the bottom of the battery pack to the outside of the battery pack along the exhaust channel. By setting the exhaust channel at the bottom of the battery pack, the exhaust channel is completely isolated from the top cold plate 400, and the high-temperature gas will not come into contact with the cold plate 400 and the thermally conductive structural adhesive, avoiding damage to the heat dissipation system of the battery pack and ensuring the heat dissipation efficiency of the battery cell 210 during normal operation.

[0069] like Figure 10As shown, in one embodiment, a battery pack short-circuit unit 600 is also included, located between the transverse side beam 120 and the crossbeam 140 near the transverse side beam 120, and connected to the housing 100. The battery pack short-circuit unit 600 abuts against the lower end face of the cold plate 400 along the Z direction, and a heat-conducting element is provided between the battery pack short-circuit unit and the cold plate 400.

[0070] In this embodiment, the Battery Disconnect Unit (BDU) 600 is an electrical safety component used to quickly disconnect the main circuit when the battery pack experiences overcurrent, short circuit, or overtemperature, preventing the fault from escalating. The BDU is installed in the reserved space between the transverse side beam 120 of the housing 100 and the crossbeam 140 near the transverse side beam 120, and the BDU is fixedly connected to the housing 100. This allows the BDU to utilize the structural space between the transverse side beam 120 and the crossbeam 140 to achieve an integrated arrangement of electrical safety components without compressing the effective installation space of the cell module 200, effectively ensuring the volumetric energy density of the battery pack and fully guaranteeing the volume utilization rate of the battery pack.

[0071] The battery drain (BDU) abuts against the lower end face of the cold plate 400 along the Z-direction. This allows the cold plate 400 to dissipate heat for both the battery cell 210 and the BDU, ensuring that the BDU's operating temperature is stably controlled within a safe threshold. This prevents problems such as contact oxidation, increased contact resistance, relay malfunction, or premature fuse blowing caused by high temperatures, guaranteeing the effectiveness of the BDU's functions under high-rate charging / discharging or high-temperature environments, thereby effectively improving the safety of the battery cell 210 in the battery pack. A thermally conductive component, such as a thermal pad or thermal adhesive, is also provided between the BDU and the cold plate 400. This component effectively eliminates the gap between the BDU and the cold plate 400, allowing heat to be transferred directly through the high thermal conductivity of the component, significantly reducing thermal resistance and ensuring the BDU's heat dissipation efficiency.

[0072] Other possible implementations include insulation cotton 700, which is placed above the cold plate 400 along the Z direction to ensure that the battery pack can maintain stable insulation performance under different temperature environments, providing reliable protection for the normal operation of the battery pack in low-temperature environments.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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; Several battery cell modules are arranged in rows along the X and Y directions in the installation space, and each battery cell module has several battery cells arranged sequentially along the X direction. A support plate is connected to the bottom of the housing along the Z direction, and the lower end face of the battery cell is bonded to the support plate. A cold plate is bonded to the upper end face of the battery cell and covers the upper end face of the housing. The height H1 of the cold plate satisfies 5mm≤H1≤7mm, and the height H2 of the support plate satisfies 8mm≤H2≤12mm and 0.65≤H1 / H2≤0.

8. The support plate is provided with several hollow areas extending along the X direction at intervals along the Y direction, and the lower end face of the battery cell is provided with an explosion-proof valve, which corresponds to the hollow area.

2. The battery pack according to claim 1, characterized in that, The bonding area between the upper end face of the battery cell and the cold plate accounts for ≥80% of the area of ​​the upper end face of the battery cell; the bonding area between the lower end face of the battery cell and the support plate accounts for ≥50% of the area of ​​the lower end face of the battery cell.

3. The battery pack according to claim 1, characterized in that, The housing is provided with longitudinal beams extending along the X direction and multiple transverse beams extending along the Y direction, all of which are arranged within the installation space to divide the installation space into multiple sub-installation spaces, each of which is used to store the battery cell module. Along the Y direction, both ends of the crossbeam are connected to the longitudinal side beam, and the width of the crossbeam is 15mm-40mm; The two ends of the longitudinal beam are respectively connected to the transverse beam near the transverse side beam, and the width of the longitudinal beam is 15mm-40mm; The ratio of the height H3 of the crossbeam to the height H4 of the longitudinal beam satisfies H3 / H4≥2.

4. The battery pack according to claim 3, characterized in that, The ratio of the height H5 of the battery cell to the height H6 of the housing satisfies 0.9 ≤ H5 / H6 ≤ 0.95; The ratio of the height H3 of the crossbeam to the height H5 of the battery cell satisfies H3 / H5≥0.

8.

5. The battery pack according to claim 1, characterized in that, The length of the housing along the X direction is L1, satisfying 600mm≤L1≤2200mm; the width of the housing along the Y direction is W1, satisfying 800mm≤W1≤1500mm; the length of the battery cell is L2, satisfying 250mm≤L2≤600mm; the width of the battery cell is W2, satisfying 10mm≤W2≤30mm; the ratio of the length L2 of the battery cell to the width W1 of the housing satisfies L2 / W1≥0.

3.

6. The battery pack according to claim 5, characterized in that, The battery cell is a ternary system battery cell, and there is a gap between two adjacent battery cells. The gap includes a first gap and a second gap. The first gap and the second gap are arranged sequentially. The first gap is 3mm-5mm, the second gap is 1mm-2mm, and the sum of the first gap and the second gap is 1 / 6 W2-1 / 3 W2.

7. The battery pack according to claim 5, characterized in that, The battery cell is a lithium iron phosphate battery cell, and there is a third gap between two adjacent battery cells. The third gap is 0.5mm-1mm and has a weight of 1% W2-5% W2.

8. The battery pack according to claim 1, characterized in that, It also includes a bottom guard plate, located below the support plate along the Z direction and connected to the housing. The bottom of the support plate has a protrusion that protrudes towards the bottom guard plate and abuts against the bottom guard plate. In the hollow area, the support plate and the bottom guard plate form an exhaust channel, and the explosion-proof valve is located in the exhaust channel.

9. The battery pack according to claim 3, characterized in that, It also includes a battery pack circuit breaker unit, located between the transverse side beam and the crossbeam near the transverse side beam, and connected to the housing. The battery pack circuit breaker unit abuts against the lower end face of the cold plate along the Z direction, and a heat-conducting element is provided between the battery pack circuit breaker unit and the cold plate.

10. An electrical appliance, characterized in that, include: The battery pack as described in any one of claims 1 to 9.

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